US20190202502A1 - Panel - Google Patents
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- Publication number
- US20190202502A1 US20190202502A1 US16/295,985 US201916295985A US2019202502A1 US 20190202502 A1 US20190202502 A1 US 20190202502A1 US 201916295985 A US201916295985 A US 201916295985A US 2019202502 A1 US2019202502 A1 US 2019202502A1
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- US
- United States
- Prior art keywords
- protrusions
- protrusion
- panel
- ridge line
- load point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D25/00—Superstructure or monocoque structure sub-units; Parts or details thereof not otherwise provided for
- B62D25/20—Floors or bottom sub-units
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
- E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
- E04C2/08—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of metal, e.g. sheet metal
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
- E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
- E04C2/30—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by the shape or structure
- E04C2/32—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by the shape or structure formed of corrugated or otherwise indented sheet-like material; composed of such layers with or without layers of flat sheet-like material
- E04C2/326—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by the shape or structure formed of corrugated or otherwise indented sheet-like material; composed of such layers with or without layers of flat sheet-like material with corrugations, incisions or reliefs in more than one direction of the element
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D25/00—Superstructure or monocoque structure sub-units; Parts or details thereof not otherwise provided for
- B62D25/20—Floors or bottom sub-units
- B62D25/2054—Load carrying floors for commercial vehicles
Definitions
- the present invention relates to a panel, particularly to a panel having a load point to which a load is applied from the outside.
- JP 5218633B discloses a panel having a plurality of protrusions and a plurality of recesses. Each protrusion has a flat top face. Each recess has a flat bottom face. The protrusions and the recesses are alternately arranged in rows and columns.
- JP 2012-148290A discloses a sheet material having protrusions and recesses.
- this sheet material many imaginary squares are combined vertically and horizontally to form a sheet surface, and the sheet surface has a protrusion-and-recess pattern.
- a basic configuration where first and second regions are formed in the imaginary square, and more than one of various basic configurations derived from the basic configuration are butted together at their peripheral edges such that the first regions are butted together and the second regions are butted together; thus, an entire configuration of the sheet surface is obtained.
- the sheet material is configured in a manner that the protrusion-and-recess pattern is formed over the entire sheet surface by upwardly raising the first regions and downwardly recessing the second regions.
- JP 2009-286249A discloses a floor panel provided with a protrusion.
- triangular flat surfaces are combined to have an angle.
- a flat surface is formed around the protrusion.
- JP 2006-297966A discloses a floor structure of a vehicle body.
- This floor structure includes a floor panel.
- the floor panel is provided with beads.
- the beads have a concentric arc shape whose center is a portion where a side sill and a cross-member intersect each other.
- Patent Literature 1 JP 5218633B
- Patent Literature 2 JP 2012-148290A
- Patent Literature 3 JP 2009-286249A
- Patent Literature 4 JP 2006-297966A
- the above panels include a panel on which a heavy object is placed, such as a floor panel of an automobile. Such a panel needs high surface rigidity.
- surface rigidity indicates a degree to which a surface can withstand, without bending, a force pressing the surface.
- the present inventors studied the surface rigidity of the panels having protrusions and recesses described in the above cited literatures. The results revealed that none of the panels were adequate in improving surface rigidity. Specifically, since the protrusions and recesses formed in the panels described in the above cited literatures are not designed in consideration of a point to which a load is applied, improvement in surface rigidity is not adequate.
- the present invention has been made in view of the above problem, and an object of the present invention is to provide a panel whose surface rigidity can be improved appropriately in accordance with a load.
- a panel including: a load point to which a load is applied from the outside; and a protrusion that protrudes from a surface of the panel and is formed continuously or discontinuously around the load point.
- the protrusion intersects, at a plurality of positions, each of a plurality of virtual straight lines extending radially from the load point.
- the load point may be a junction with another member.
- the panel may include a plurality of the load points. At least one of density, a formation range, and a cross-sectional shape of the protrusion may differ in accordance with an assumed load applied to the load point.
- side faces of the protrusions may be continuous via a curved surface.
- a ridge line of the protrusion may perpendicularly intersect the plurality of virtual straight lines.
- the plurality of virtual straight lines may be straight lines connecting the load point and a plurality of vertices of the panel.
- the protrusion may include a top face parallel to the surface of the panel.
- the protrusion may include a plurality of ring-shaped protrusions formed concentrically.
- the center of the ring-shaped protrusion may coincide with the load point.
- the protrusion may include a spiral-shaped protrusion whose base point is the load point.
- the panel may be made of a steel sheet.
- the panel may be a floor panel of an automobile.
- FIG. 1 is a plan view of a panel according to a first embodiment.
- FIG. 2 is a II-II cross-sectional view of FIG. 1 .
- FIG. 3 is a plan view of a panel according to a second embodiment.
- FIG. 4 is a IV-IV cross-sectional view of FIG. 3 .
- FIG. 5 is a plan view of a panel according to a third embodiment.
- FIG. 6 is a VI-VI cross-sectional view of FIG. 5 .
- FIG. 7 is a plan view of a panel according to a fourth embodiment.
- FIG. 8 is a VIII-VIII cross-sectional view of FIG. 7 .
- FIG. 9 is a plan view of a panel according to a fifth embodiment.
- FIG. 10 is a X-X cross-sectional view of FIG. 9 .
- FIG. 11 is a plan view of a panel according to a sixth embodiment.
- FIG. 12 is a XII-XII cross-sectional view of FIG. 11 .
- FIG. 13 is a plan view of a panel according to a seventh embodiment.
- FIG. 14 is a XIV-XIV cross-sectional view of FIG. 13 .
- FIG. 15 is a plan view of a panel according to an eighth embodiment.
- FIG. 16 is a XVI-XVI cross-sectional view of FIG. 15 .
- FIG. 17 is a plan view for describing circumferential lengths of protrusions.
- FIG. 18 is a plan view of a panel according to a ninth embodiment.
- FIG. 19 is a XVI-XVI cross-sectional view of FIG. 17 .
- FIG. 20 is a plan view of a panel according to a tenth embodiment.
- FIG. 21 is an explanatory diagram illustrating a modification of the tenth embodiment.
- FIG. 22 is a plan view of a panel according to an eleventh embodiment.
- FIG. 23 is an explanatory diagram illustrating a modification of the eleventh embodiment.
- FIG. 24 is a plan view of a panel according to a twelfth embodiment.
- FIG. 25 is a conceptual diagram illustrating a protrusion of a panel according to Comparative Example 1.
- FIG. 26 is a conceptual diagram illustrating a protrusion of a panel according to Comparative Example 2.
- FIG. 27 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 20-mm-square square shape.
- FIG. 28 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 50-mm-square square shape.
- FIG. 29 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 100-mm-square square shape.
- FIG. 30 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 150-mm-square square shape.
- FIG. 31 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 20-mm-square square shape.
- FIG. 32 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 50-mm-square square shape.
- FIG. 33 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 100-mm-square square shape.
- FIG. 34 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 150-mm-square square shape.
- FIG. 1 is a plan view of the panel 10 .
- FIG. 2 is a II-II cross-sectional view of FIG. 1 .
- the panel 10 has a square shape in a planar view.
- the panel 10 has, in a planar view, four vertices V 11 , V 12 , V 13 , and V 14 and four sides S 11 , S 12 , S 13 , and S 14 .
- the side S 11 connects the vertex V 11 and the vertex V 12 .
- the side S 12 connects the vertex V 12 and the vertex V 13 .
- the side S 13 connects the vertex V 13 and the vertex V 14 .
- the side S 14 connects the vertex V 14 and the vertex V 11 .
- This panel 10 includes a load point P L , a reinforced section 12 , and a peripheral edge 14 .
- the panel 10 is, for example, a support plate that supports a heavy object. Specific examples are a floor panel for an automobile, a trunk lid inner panel, a floor for a building material, a support plate used for a copying machine or a refrigerator, and a casing of an attache case.
- a material of the panel 10 may be, for example, a metal (e.g., steel, aluminum alloy, titanium, or stainless steel) or a synthetic resin.
- the panel 10 is produced by press working, for example. Improving the formability of the panel 10 by heating, as in warm forming or hot stamping, facilitates forming by press working.
- the panel 10 is made of a synthetic resin
- the panel 10 is produced by injection molding, for example.
- the reinforced section 12 as a whole has, in a planar view, a square shape one size smaller than that of the panel 10 .
- the peripheral edge 14 is formed around the reinforced section 12 .
- the panel 10 is attached to another member at the peripheral edge 14 .
- the panel 10 is attached to another member at positions of the peripheral edge 14 that correspond to the four corners of the panel 10 .
- the reinforced section 12 is provided with a plurality of protrusions 16 around the load point P L .
- the plurality of protrusions 16 include a first protrusion 161 , a plurality (two in the present embodiment) of second protrusions 162 , and a plurality (four in the present embodiment) of third protrusions 163 .
- the numbers of the second protrusions 162 and the third protrusions 163 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later.
- the planar shape of the panel 10 is not particularly limited, and may be any of various shapes.
- the planar shape of the panel 10 may be, instead of a square, a rectangle or a rectangle having one of its four corners cut off.
- the load point P L indicates a position where a load is applied to the panel 10 from the outside.
- a load applied to the panel 10 means a load that is applied to the panel 10 from a direction intersecting a plane along which the panel 10 extends. Accordingly, the load point P L does not include a position where a load is applied to the panel 10 from a direction along the plane along which the panel 10 extends.
- the load point P L is typically configured as a junction with another member.
- the panel 10 is a floor panel of a vehicle
- a joint position of a support member on which a seat in a cabin is placed may serve as the load point P L .
- the load point P L of the floor panel is provided with a tapped hole, and the support member is joined to the floor panel with a bolt, etc.
- a load is applied to the load point P L .
- a method for joining another member to the load point P L of the panel 10 is not limited to the method using a bolt, etc., and may be joining by welding or joining by using an adhesive. Moreover, another member need not be joined to the load point P L of the panel 10 . For example, the panel 10 and another member may come into contact at the load point P L to cause a load to be applied to the load point P L .
- the first protrusion 161 protrudes from a surface 101 of the panel 10 .
- the panel 10 has, at a position where the first protrusion 161 is formed, a recess opening toward the rear surface side.
- the recess has a shape corresponding to the first protrusion 161 .
- the first protrusion 161 is formed concentrically with the load point P L of the panel 10 in a planar view.
- the first protrusion 161 includes a top face 18 and a side face 20 .
- the top face 18 has a circular shape in a planar view. As viewed from the thickness direction of the panel 10 , the center of the top face 18 coincides with the load point P L . The top face 18 is away from the surface 101 in the thickness direction of the panel 10 . The top face 18 is parallel to the surface 101 .
- the protrusion height of the first protrusion 161 i.e., the distance between the top face 18 and the surface 101 in the thickness direction of the panel 10 , is 0.5 to 50 mm, for example.
- the protrusion height of the first protrusion 161 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later.
- the side face 20 has a circular ring shape in a planar view.
- the inner circumferential edge of the side face 20 is farther from the surface 101 than the outer circumferential edge of the side face 20 is.
- the inner circumferential edge of the side face 20 is connected to the edge of the top face 18 .
- the outer circumferential edge of the side face 20 is connected to the surface 101 .
- Surface rigidity increases as an inclination angle ⁇ of the side face 20 with respect to the surface 101 becomes larger.
- local sheet thickness reduction or cracking becomes more likely to occur during forming as the inclination angle ⁇ of the side face 20 with respect to the surface 101 becomes larger.
- the inclination angle ⁇ is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later. On that occasion, ease of forming of a material may also be taken into consideration. In the case of a steel material, the inclination angle ⁇ is preferably 15 to 60 degrees, further preferably 45 degrees.
- a ridge line 181 formed as the boundary between the top face 18 and the side face 20 has a circular shape in a planar view. As illustrated in FIG. 1 , the ridge line 181 intersects four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the virtual straight line L 11 connects the load point P L and the vertex V 11 in a planar view.
- the virtual straight line L 12 connects the load point P L and the vertex V 12 in a planar view.
- the virtual straight line L 13 connects the load point P L and the vertex V 13 in a planar view.
- the virtual straight line L 14 connects the load point P L and the vertex V 14 in a planar view.
- the four virtual straight lines L 11 , L 12 , L 13 , and L 14 extend radially from the load point P L .
- the ridge line 181 perpendicularly intersects all of the virtual straight lines extending radially from the load point P L .
- the two second protrusions 162 each protrude from the surface 101 .
- the two second protrusions 162 each have a circular ring shape in a planar view.
- the two second protrusions 162 are formed concentrically with respect to the load point P L .
- the panel 10 has, at a position where the second protrusion 162 is formed, a recess opening toward the rear surface side.
- the recess has a shape corresponding to the second protrusion 162 .
- one of the two second protrusions 162 that is closer to the load point P L will be called a first ring-shaped protrusion 22
- one of the two second protrusions 162 that is farther from the load point P L will be called a second ring-shaped protrusion 24 .
- the first ring-shaped protrusion 22 includes a top face 26 , a side face 28 , and a side face 30 .
- the top face 26 has a circular ring shape in a planar view.
- the inner diameter of the top face 26 is larger than the diameter of the top face 18 .
- the center of the top face 26 coincides with the load point P L .
- the top face 26 is away from the surface 101 in the thickness direction of the panel 10 .
- the top face 26 is parallel to the surface 101 .
- the protrusion height of the first ring-shaped protrusion 22 i.e., the distance between the top face 26 and the surface 101 in the thickness direction of the panel 10 , is 0.5 to 50 mm, for example.
- the protrusion height of the first ring-shaped protrusion 22 may be the same as or different from the protrusion height of the first protrusion 161 .
- the protrusion height of the first ring-shaped protrusion 22 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later.
- the side face 28 is located closer to the load point P L than the top face 26 is.
- the side face 28 has a circular ring shape in a planar view.
- the outer circumferential edge of the side face 28 is farther from the surface 101 than the inner circumferential edge of the side face 28 is.
- the inner circumferential edge of the side face 28 is connected to the surface 101 .
- the outer circumferential edge of the side face 28 is connected to the inner circumferential edge of the top face 26 .
- An inclination angle ⁇ of the side face 28 with respect to the surface 101 is set similarly to the inclination angle ⁇ of the side face 20 .
- the inclination angle ⁇ of the side face 28 with respect to the surface 101 may be the same as or different from the inclination angle ⁇ of the side face 20 .
- the inclination angle ⁇ of the side face 28 with respect to the surface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later. On that occasion, the distance from the load point P L and ease of forming of a material may also be taken into consideration.
- a ridge line 261 formed as the boundary between the top face 26 and the side face 28 has a circular shape in a planar view.
- the ridge line 261 has a larger diameter than the ridge line 181 .
- the ridge line 261 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the ridge line 261 perpendicularly intersects all of the virtual straight lines extending radially from the load point P L .
- the side face 30 is farther from the load point P L than the top face 26 is.
- the side face 30 has a circular ring shape in a planar view.
- the inner circumferential edge of the side face 30 is farther from the surface 101 than the outer circumferential edge of the side face 30 is.
- the inner circumferential edge of the side face 30 is connected to the outer circumferential edge of the top face 26 .
- the outer circumferential edge of the side face 30 is connected to the surface 101 .
- An inclination angle ⁇ of the side face 30 with respect to the surface 101 is set similarly to the inclination angle ⁇ of the side face 20 .
- the inclination angle ⁇ of the side face 30 with respect to the surface 101 may be the same as or different from the inclination angles ⁇ of the side face 20 and the side face 28 .
- the inclination angle ⁇ of the side face 30 with respect to the surface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later. On that occasion, the distance from the load point P L and ease of forming of a material may also be taken into consideration.
- a ridge line 262 formed as the boundary between the top face 26 and the side face 30 has a circular shape in a planar view.
- the ridge line 262 has a larger diameter than the ridge line 261 .
- the ridge line 262 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the distance between the ridge line 262 and the ridge line 261 i.e., the width of the top face 26 , is 0.5 to 50 mm, for example.
- the ridge line 262 perpendicularly intersects all of the virtual straight lines extending radially from the load point P L .
- the second ring-shaped protrusion 24 includes a top face 32 , a side face 34 , and a side face 36 .
- the top face 32 has a circular ring shape in a planar view. As viewed from the thickness direction of the panel 10 , the center of the top face 32 coincides with the load point P L . The top face 32 is away from the surface 101 in the thickness direction of the panel 10 . The top face 32 is parallel to the surface 101 .
- the protrusion height of the second ring-shaped protrusion 24 i.e., the distance between the top face 32 and the surface 101 in the thickness direction of the panel 10 , is 0.5 to 50 mm, for example.
- the protrusion height of the second ring-shaped protrusion 24 may be the same as or different from the protrusion heights of the first protrusion 161 and the first ring-shaped protrusion 22 .
- the protrusion height of the second ring-shaped protrusion 24 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later.
- the side face 34 is located closer to the load point P L than the top face 32 is.
- the side face 34 has a circular ring shape in a planar view.
- the outer circumferential edge of the side face 34 is farther from the surface 101 than the inner circumferential edge of the side face 34 is.
- the inner circumferential edge of the side face 34 is connected to the surface 101 .
- the outer circumferential edge of the side face 34 is connected to the inner circumferential edge of the top face 32 .
- An inclination angle ⁇ of the side face 34 with respect to the surface 101 is set similarly to the inclination angle ⁇ of the side face 20 .
- the inclination angle ⁇ of the side face 34 with respect to the surface 101 may be the same as or different from the inclination angles ⁇ of the side face 20 , the side face 28 , and the side face 30 .
- the inclination angle ⁇ of the side face 34 with respect to the surface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later. On that occasion, the distance from the load point P L and ease of forming of a material may also be taken into consideration.
- a ridge line 321 formed as the boundary between the top face 32 and the side face 34 has a circular shape in a planar view.
- the ridge line 321 has a larger diameter than the ridge line 262 .
- the ridge line 321 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the ridge line 321 perpendicularly intersects all of the virtual straight lines extending radially from the load point P L .
- the side face 36 is farther from the load point P L than the top face 32 is.
- the side face 36 has a circular ring shape in a planar view.
- the inner circumferential edge of the side face 36 is farther from the surface 101 than the outer circumferential edge of the side face 36 is.
- the inner circumferential edge of the side face 36 is connected to the outer circumferential edge of the top face 32 .
- the outer circumferential edge of the side face 36 is connected to the surface 101 .
- An inclination angle ⁇ of the side face 36 with respect to the surface 101 is set similarly to the inclination angle ⁇ of the side face 20 .
- the inclination angle ⁇ of the side face 36 with respect to the surface 101 may be the same as or different from the inclination angles ⁇ of the side face 20 , the side face 28 , the side face 30 , and the side face 34 .
- the inclination angle ⁇ of the side face 36 with respect to the surface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later. On that occasion, the distance from the load point P L and ease of forming of a material may also be taken into consideration.
- a ridge line 322 formed as the boundary between the top face 32 and the side face 36 has a circular shape in a planar view.
- the ridge line 322 has a larger diameter than the ridge line 321 .
- the ridge line 322 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the ridge line 322 perpendicularly intersects all of the virtual straight lines extending radially from the load point P L .
- the distance between the ridge line 322 and the ridge line 321 i.e., the width of the top face 32 , is 1 to 50 mm, for example.
- the width of the top face 32 may be the same as or different from the width of the top face 26 .
- the four third protrusions 163 each protrude from the surface 101 .
- the four third protrusions 163 each have a substantially triangular shape in a planar view.
- the four third protrusions 163 are located at the four corners of the reinforced section 12 .
- the four third protrusions 163 are located on a circle whose center is the load point P L .
- the panel 10 has, at a position where the third protrusion 163 is formed, a recess opening toward the rear surface side.
- the recess has a shape corresponding to the third protrusion 163 .
- the four third protrusions 163 each include a top face 38 , a side face 40 , and a side face 42 .
- the top face 38 has a substantially trapezoidal shape in a planar view.
- the top face 32 is away from the surface 101 in the thickness direction of the panel 10 .
- the top face 38 is parallel to the surface 101 .
- the protrusion height of the third protrusion 163 i.e., the distance between the top face 38 and the surface 101 in the thickness direction of the panel 10 , is 0.5 to 50 mm, for example.
- the protrusion height of the third protrusion 163 may be the same as or different from the protrusion heights of the first protrusion 161 , the first ring-shaped protrusion 22 , and the second ring-shaped protrusion 24 .
- the protrusion height of the third protrusion 163 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later.
- the side face 40 is located closer to the load point P L than the top face 38 is.
- the side face 40 has a substantially trapezoidal shape in a planar view.
- the lower end edge of the side face 40 is connected to the surface 101 .
- the upper end edge of the side face 40 is connected to the top face 38 .
- An inclination angle ⁇ of the side face 40 with respect to the surface 101 is set similarly to the inclination angles ⁇ of the side face 20 , the side face 28 , the side face 30 , the side face 34 , and the side face 36 .
- the inclination angle ⁇ of the side face 40 with respect to the surface 101 may be the same as or different from the inclination angles ⁇ of the side face 20 , the side face 28 , the side face 30 , the side face 34 , and the side face 36 .
- the inclination angle ⁇ of the side face 40 with respect to the surface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later. On that occasion, the distance from the load point P L and ease of forming of a material may also be taken into consideration.
- the side face 42 is farther from the load point P L than the top face 38 is.
- the side face 42 has a substantially trapezoidal shape in a planar view.
- the lower end edge of the side face 42 is connected to the surface 101 .
- the upper end edge of the side face 42 is connected to the top face 38 .
- An inclination angle ⁇ of the side face 42 with respect to the surface 101 is set similarly to the inclination angles ⁇ of the side face 20 , the side face 28 , the side face 30 , the side face 34 , the side face 36 , and the side face 40 .
- the inclination angle ⁇ of the side face 42 with respect to the surface 101 may be the same as or different from the inclination angles ⁇ of the side face 20 , the side face 28 , the side face 30 , the side face 34 , the side face 36 , and the side face 40 .
- the inclination angle ⁇ of the side face 42 with respect to the surface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as will be described later. On that occasion, the distance from the load point P L and ease of forming of a material may also be taken into consideration.
- a ridge line 381 formed as the boundary between the top face 38 and the side face 40 intersects one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- a ridge line 382 formed as the boundary between the top face 38 and the side face 42 intersects one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the distance between the ridge line 382 and the ridge line 381 i.e., the width of the top face 38 , is 1 to 50 mm, for example.
- the width of the top face 38 may be the same as or different from the widths of the top face 26 and the top face 32 .
- modes of the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 are set in consideration of surface rigidity against an assumed load applied to the load point P L .
- the heights of the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 may be made larger for larger assumed loads.
- the inclination angles ⁇ of the side faces 20 , 28 , 30 , 34 , 36 , 40 , and 42 forming the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 can be made larger for larger assumed loads.
- the heights of the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 and the inclination angles ⁇ of the side faces 20 , 28 , 30 , 34 , 36 , 40 , and 42 are elements of the cross-sectional shapes of the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 .
- Such elements of the cross-sectional shapes may have an influence on the magnitude of the surface rigidity of each of the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 .
- the heights of the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 and the inclination angles ⁇ of the side faces 20 , 28 , 30 , 34 , 36 , 40 , and 42 are set in accordance with the magnitude of the assumed load.
- the panel 10 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the widths of the top faces 18 , 26 , 32 , and 38 and the intervals between the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 may be made smaller for larger assumed loads.
- the widths of the top faces 18 , 26 , 32 , and 38 and the intervals between the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 have an influence on the density of the protrusions 16 of the panel 10 .
- the density of the protrusions 16 may have an influence on the magnitude of the surface rigidity of each region of the panel 10 .
- the widths of the top faces 18 , 26 , 32 , and 38 and the intervals between the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 are set in accordance with the magnitude of the assumed load.
- the panel 10 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces 20 , 28 , 30 , 34 , 36 , 40 , and 42 forming the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 may all be the same, or some or all may be different.
- the widths of the top faces 18 , 26 , 32 , and 38 may all be the same, or some or all may be different.
- the intervals between the first protrusion 161 , the second protrusions 162 , and the third protrusions 163 may all be the same, or some or all may be different.
- the presence or absence of the third protrusions 163 and the number of the second protrusions 162 may also be set in accordance with the magnitude of the assumed load.
- the presence or absence of the third protrusions 163 and the number of the second protrusions 162 have an influence on a formation range of the protrusions 16 .
- the formation range of the protrusions 16 may have an influence on the magnitude of the surface rigidity of the entire panel 10 . Changing the formation range of the protrusions 16 also allows the panel 10 to have appropriate surface rigidity in accordance with the assumed load.
- the ridge lines 181 , 261 , 262 , 321 , 322 , 381 , and 382 intersect, at a plurality of positions, the virtual straight lines L 11 , L 12 , L 13 , and L 14 extending radially from the load point P L .
- This increases the moment of inertia of area of a cross section taken along each of the virtual straight lines L 11 , L 12 , L 13 , and L 14 . This results in an improvement in the surface rigidity of the panel 10 .
- the anisotropy of the moment of inertia of area with respect to a load can be reduced. This provides appropriate surface rigidity against the load that the panel 10 may receive.
- the first ring-shaped protrusion 22 , the second ring-shaped protrusion 24 , and the third protrusion 163 have the top faces 26 , 32 , and 38 , respectively.
- This increases the number of ridge lines that intersect the virtual straight lines extending radially from the load point P L .
- the moment of inertia of area is further increased, making it easy to provide appropriate surface rigidity against the load that the panel 10 may receive.
- the ridge lines 181 , 261 , 262 , 321 , 322 , 381 , and 382 perpendicularly intersect the virtual straight lines L 11 , L 12 , L 13 , and L 14 connecting the load point P L and the vertices V 11 , V 12 , V 13 , and V 14 of the panel 10 , out of the virtual straight lines extending radially from the load point P L .
- This increases the number of ridge lines that intersect the virtual straight lines L 11 , L 12 , L 13 , and L 14 between the load point P L and the vertices V 11 , V 12 , V 13 , and V 14 .
- the shapes of the protrusions 16 in the panel 10 according to the present embodiment are not limited to circular shapes. Modifications of protrusions are described below in second to ninth embodiments.
- FIG. 3 is a plan view of the panel 50 .
- FIG. 4 is a IV-IV cross-sectional view of FIG. 3 .
- the panel 50 according to the second embodiment differs from the panel 10 of the first embodiment in a configuration of a plurality of protrusions 52 .
- the configuration of the protrusions 52 is mainly described below; description is given on differences from the protrusions 16 of the first embodiment.
- the protrusions 52 include a first protrusion 521 and a plurality (two in the present embodiment) of second protrusions 522 .
- the number of the second protrusions 522 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L .
- the first protrusion 521 protrudes from a surface 501 of the panel 50 .
- the first protrusion 521 is formed concentrically with the load point P L of the panel 50 in a planar view.
- the first protrusion 521 includes a top face 54 .
- the top face 54 has a square shape in a planar view. As viewed from the thickness direction of the panel 50 , the center of the top face 54 coincides with the load point P L .
- the first protrusion 521 includes a ridge line 541 .
- the ridge line 541 has a square shape in a planar view. As illustrated in FIG. 3 , the ridge line 541 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 . Although not shown, the ridge line 541 intersects all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by the ridge line 541 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the two second protrusions 522 each protrude from the surface 501 .
- the two second protrusions 522 each have a square frame shape in a planar view.
- the two second protrusions 522 are formed concentrically with respect to the load point P L .
- one of the two second protrusions 522 that is closer to the load point P L will be called a first ring-shaped protrusion 56
- one of the two second protrusions 522 that is farther from the load point P L will be called a second ring-shaped protrusion 58 .
- the first ring-shaped protrusion 56 includes a top face 60 .
- the top face 60 has a square frame shape in a planar view.
- the first ring-shaped protrusion 56 includes a ridge line 601 and a ridge line 602 .
- the ridge line 601 is located closer to the load point P L than the ridge line 602 is.
- the ridge line 601 and the ridge line 602 each have a square shape in a planar view. As illustrated in FIG. 3 , the ridge line 601 and the ridge line 602 intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- the ridge line 601 and the ridge line 602 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge line 601 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge line 602 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the second ring-shaped protrusion 58 includes a top face 62 .
- the top face 62 has a square frame shape in a planar view.
- the second ring-shaped protrusion 58 includes a ridge line 621 and a ridge line 622 .
- the ridge line 621 is located closer to the load point P L than the ridge line 622 is.
- the ridge line 621 and the ridge line 622 each have a square shape in a planar view. As illustrated in FIG. 3 , the ridge line 621 and the ridge line 622 intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- the ridge line 621 and the ridge line 622 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge line 621 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge line 622 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- modes of the first protrusion 521 and the second protrusions 522 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the first protrusion 521 and the second protrusions 522 and the inclination angles ⁇ of the side faces forming the first protrusion 521 and the second protrusions 522 can be set in accordance with the magnitude of the assumed load. In addition, as in the panel 10 according to the first embodiment, the widths of the top faces 54 , 60 , and 62 and the intervals between the first protrusion 521 and the second protrusions 522 can be set in accordance with the magnitude of the assumed load. Thus, the panel 50 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusion 521 and the second protrusions 522 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the first protrusion 521 and the second protrusions 522 may all be the same, or some or all may be different.
- the widths of the top faces 54 , 60 , and 62 may all be the same, or some or all may be different.
- the intervals between the first protrusion 521 and the second protrusions 522 may all be the same, or some or all may be different.
- the number of the second protrusions 522 can also be set in accordance with the magnitude of the assumed load.
- the panel 50 according to the second embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 5 is a plan view of the panel 70 .
- FIG. 6 is a VI-VI cross-sectional view of FIG. 5 .
- the panel 70 according to the third embodiment differs from the panel 10 of the first embodiment in a configuration of a plurality of protrusions 72 .
- the configuration of the protrusions 72 is mainly described below; description is given on differences from the protrusions 16 of the first embodiment.
- the protrusions 72 include a first protrusion 721 , a plurality (two in the present embodiment) of second protrusions 722 , and a plurality (four in the present embodiment) of third protrusions 723 .
- the numbers of the second protrusions 722 and the third protrusions 723 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as in the panel 10 of the first embodiment.
- the first protrusion 721 protrudes from a surface 701 of the panel 70 .
- the first protrusion 721 is formed concentrically with the load point P L of the panel 70 in a planar view.
- the first protrusion 721 includes a top face 74 .
- the top face 74 has a square shape in a planar view. As viewed from the thickness direction of the panel 70 , the center of the top face 74 coincides with the load point P L .
- the first protrusion 721 includes a ridge line 741 .
- the ridge line 741 has a square shape in a planar view. As illustrated in FIG. 5 , the ridge line 741 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly. Although not shown, the ridge line 741 intersects all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by the ridge line 741 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the two second protrusions 722 each protrude from the surface 701 .
- the two second protrusions 722 each have a square frame shape in a planar view.
- the two second protrusions 722 are formed concentrically with respect to the load point P L .
- one of the two second protrusions 722 that is closer to the load point P L will be called a first ring-shaped protrusion 76
- one of the two second protrusions 722 that is farther from the load point P L will be called a second ring-shaped protrusion 78 .
- the first ring-shaped protrusion 76 includes a top face 80 .
- the top face 80 has a square frame shape in a planar view.
- the first ring-shaped protrusion 76 includes a ridge line 801 and a ridge line 802 .
- the ridge line 801 is located closer to the load point P L than the ridge line 802 is.
- the ridge line 801 and the ridge line 802 each have a square shape in a planar view. As illustrated in FIG. 5 , the ridge line 801 and the ridge line 802 intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the ridge line 801 and the ridge line 802 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge line 801 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge line 802 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the second ring-shaped protrusion 78 includes a plurality (four in the present embodiment) of top faces 82 .
- the top face 82 has a trapezoidal shape in a planar view.
- the second ring-shaped protrusion 78 includes four ridge lines 821 and four ridge lines 822 .
- the ridge lines 821 are located closer to the load point P L than the ridge lines 822 are. As illustrated in FIG. 5 , the ridge lines 821 and the ridge lines 822 intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the ridge lines 821 and the ridge lines 822 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge lines 821 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge lines 822 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the four third protrusions 723 each protrude from the surface 701 .
- the four third protrusions 723 each have a substantially triangular shape in a planar view.
- the four third protrusions 723 are located around the load point P L serving as the center.
- the four third protrusions 723 are farther from the load point P L than the second ring-shaped protrusion 78 is.
- the third protrusion 723 includes a top face 84 .
- the top face 84 has a trapezoidal shape in a planar view.
- the third protrusion 723 includes a ridge line 841 and a ridge line 842 .
- the ridge line 841 is located closer to the load point P L than the ridge line 842 is. As illustrated in FIG. 5 , the ridge line 841 and the ridge line 842 perpendicularly intersect one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- modes of the first protrusion 721 , the second protrusions 722 , and the third protrusions 723 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the first protrusion 721 , the second protrusions 722 , and the third protrusions 723 and the inclination angles ⁇ of the side faces forming the first protrusion 721 , the second protrusions 722 , and the third protrusions 723 can be set in accordance with the magnitude of the assumed load.
- the widths of the top faces 74 , 80 , 82 , and 84 and the intervals between the first protrusion 721 , the second protrusions 722 , and the third protrusions 723 can be set in accordance with the magnitude of the assumed load.
- the panel 70 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusion 721 , the second protrusions 722 , and the third protrusions 723 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the first protrusion 721 , the second protrusions 722 , and the third protrusions 723 may all be the same, or some or all may be different.
- the widths of the top faces 74 , 80 , 82 , and 84 may all be the same, or some or all may be different.
- the intervals between the first protrusion 721 , the second protrusions 722 , and the third protrusions 723 may all be the same, or some or all may be different.
- the numbers of the second protrusions 722 and the third protrusions 723 can also be set in accordance with the magnitude of the assumed load.
- the panel 70 according to the third embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 7 is a plan view of the panel 90 .
- FIG. 8 is a VIII-VIII cross-sectional view of FIG. 7 .
- the panel 90 according to the fourth embodiment differs from the panel 10 of the first embodiment in a configuration of a plurality of protrusions 92 .
- the configuration of the protrusions 92 is mainly described below; description is given on differences from the protrusions 16 of the first embodiment.
- the protrusions 92 include a first protrusion 921 , a second protrusion 922 , a plurality (four in the present embodiment) of third protrusions 923 , and a plurality (four in the present embodiment) of fourth protrusions 924 .
- the numbers of the second protrusions 922 , the third protrusions 923 , and the fourth protrusions 924 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as in the panel 10 of the first embodiment.
- the first protrusion 921 protrudes from a surface 901 of the panel 90 .
- the first protrusion 921 is formed concentrically with the load point P L of the panel 90 in a planar view.
- the first protrusion 921 includes a top face 93 .
- the top face 93 has a substantially square shape in a planar view. As viewed from the thickness direction of the panel 90 , the center of the top face 93 coincides with the load point P L .
- the first protrusion 921 includes a ridge line 931 .
- the ridge line 931 has a substantially square shape in a planar view. As illustrated in FIG. 7 , the ridge line 931 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly. Although not shown, the ridge line 931 intersects all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by the ridge line 931 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the second protrusion 922 protrudes from the surface 901 .
- the second protrusion 922 is formed concentrically with respect to the load point P L . In other words, the center of the second protrusion 922 coincides with the load point P L in a planar view.
- the second protrusion 922 includes four top faces 94 .
- the second protrusion 922 includes four ridge lines 941 and four ridge lines 942 .
- the ridge lines 941 are located closer to the load point P L than the ridge lines 942 are.
- the ridge lines 941 and the ridge lines 942 each have a midpoint located closer to the load point P L than the straight line connecting both ends of the ridge line 941 or the ridge line 942 is.
- the ridge lines 941 and the ridge lines 942 each have an arc shape that is convex toward the load point P L in a planar view. As illustrated in FIG. 7 , the ridge lines 941 and the ridge lines 942 perpendicularly intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- the four third protrusions 923 protrude from the surface 901 .
- the four third protrusions 923 are located around the load point P L serving as the center.
- the third protrusions 923 are farther from the load point P L than the second protrusion 922 is.
- the third protrusion 923 includes a top face 96 .
- the third protrusion 923 includes a ridge line 961 and a ridge line 962 .
- the ridge line 961 is located closer to the load point P L than the ridge line 962 is.
- the ridge line 961 and the ridge line 962 each have a midpoint located closer to the load point P L than the straight lines connecting both ends of the ridge line 961 and the ridge line 962 are.
- the ridge line 961 and the ridge line 962 each have an arc shape that is convex toward the load point P L in a planar view. As illustrated in FIG. 7 , the ridge line 961 and the ridge line 962 perpendicularly intersect one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- the four fourth protrusions 924 protrude from the surface 901 .
- the four fourth protrusions 924 are located around the load point P L serving as the center.
- the fourth protrusions 924 are farther from the load point P L than the third protrusions 923 are.
- the fourth protrusion 924 includes a top face 98 .
- the fourth protrusion 924 includes a ridge line 981 and a ridge line 982 .
- the ridge line 981 is located closer to the load point P L than the ridge line 982 is.
- the ridge line 981 and the ridge line 982 each have a midpoint located closer to the load point P L than the straight lines connecting both ends of the ridge line 981 and the ridge line 982 are.
- the ridge line 981 and the ridge line 982 each have an arc shape that is convex toward the load point P L in a planar view. As illustrated in FIG. 7 , the ridge line 981 and the ridge line 982 perpendicularly intersect one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- modes of the first protrusion 921 , the second protrusion 922 , the third protrusions 923 , and the fourth protrusions 924 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the first protrusion 921 , the second protrusion 922 , the third protrusions 923 , and the fourth protrusions 924 and the inclination angles ⁇ of the side faces forming the first protrusion 921 , the second protrusion 922 , the third protrusions 923 , and the fourth protrusions 924 can be set in accordance with the magnitude of the assumed load.
- the widths of the top faces 93 , 94 , 96 , and 98 and the intervals between the first protrusion 921 , the second protrusion 922 , the third protrusions 923 , and the fourth protrusions 924 can be set in accordance with the magnitude of the assumed load.
- the panel 90 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusion 921 , the second protrusion 922 , the third protrusions 923 , and the fourth protrusions 924 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the first protrusion 921 , the second protrusion 922 , the third protrusions 923 , and the fourth protrusions 924 may all be the same, or some or all may be different.
- the widths of the top faces 93 , 94 , 96 , and 98 may all be the same, or some or all may be different.
- the intervals between the first protrusion 921 , the second protrusion 922 , the third protrusions 923 , and the fourth protrusions 924 may all be the same, or some or all may be different.
- the numbers of the second protrusions 922 , the third protrusions 923 , and the fourth protrusions 924 can also be set in accordance with the magnitude of the assumed load.
- the panel 90 according to the fourth embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 9 is a plan view of the panel 100 .
- FIG. 10 is a X-X cross-sectional view of FIG. 9 .
- the panel 100 according to the fifth embodiment differs from the panel 10 of the first embodiment in a configuration of a plurality of protrusions 102 .
- the configuration of the protrusions 102 is mainly described below; description is given on differences from the protrusions 16 of the first embodiment.
- the panel 100 includes, as the protrusions 102 , two protrusions 1021 .
- the number of the protrusions 1021 may be one.
- Each protrusion 1021 protrudes from a surface 1001 .
- Each protrusion 1021 has a spiral shape in a planar view.
- Each protrusion 1021 includes a top face 104 .
- Each protrusion 1021 includes a ridge line 1041 and a ridge line 1042 .
- the ridge line 1041 and the ridge line 1042 each have a spiral shape in a planar view.
- the ridge line 1041 is located closer to the load point P L than the ridge line 1042 is.
- the ridge line 1041 and the ridge line 1042 intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 at a plurality of positions.
- the ridge line 1041 and the ridge line 1042 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge line 1041 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge line 1042 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- modes of the protrusions 1021 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the protrusions 1021 and the inclination angles ⁇ of the side faces forming the protrusions 1021 can be set in accordance with the magnitude of the assumed load. In addition, as in the panel 10 according to the first embodiment, the widths of the top faces 104 and the intervals between the protrusions 1021 can be set in accordance with the magnitude of the assumed load. Thus, the panel 100 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the protrusions 1021 may be the same throughout the entire range, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the protrusions 1021 may be the same throughout the entire range, or some or all may be different.
- the widths of the top faces 104 may be the same throughout the entire range, or some or all may be different.
- the intervals between the protrusions 1021 may be the same throughout the entire range, or some or all may be different.
- the number of the protrusions 1021 can also be set in accordance with the magnitude of the assumed load.
- the panel 100 according to the fifth embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 11 is a plan view of the panel 110 .
- FIG. 12 is a XII-XII cross-sectional view of FIG. 11 .
- the panel 110 according to the sixth embodiment differs from the panel 10 of the first embodiment in a configuration of a plurality of protrusions 112 .
- the configuration of the protrusions 112 is mainly described below; description is given on differences from the protrusions 16 of the first embodiment.
- the protrusions 112 include a plurality (two in the present embodiment) of first protrusions 1121 and a plurality (six in the present embodiment) of second protrusions 1122 . Note that the numbers of the first protrusions 1121 and the second protrusions 1122 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as in the panel 10 of the first embodiment.
- the first protrusions 1121 protrude from a surface 1101 .
- the first protrusions 1121 each have a spiral shape surrounding the load point P L serving as a base point in a planar view.
- the first protrusion 1121 includes a top face 114 and a top face 116 .
- the first protrusion 1121 includes a ridge line 1141 , a ridge line 1142 , a ridge line 1161 , and a ridge line 1162 .
- the ridge line 1141 and the ridge line 1142 each have a spiral shape in a planar view. As illustrated in FIG. 11 , the ridge line 1141 and the ridge line 1142 have portions perpendicularly intersecting the four virtual straight lines L 11 , L 12 , L 13 , and L 14 . Although not shown, the ridge line 1141 and the ridge line 1142 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge line 1141 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge line 1142 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the ridge line 1161 and the ridge line 1162 are parallel to each other in a planar view.
- the ridge line 1161 and the ridge line 1162 of one of the two first protrusions 1121 perpendicularly intersect the virtual straight line L 11 .
- the ridge line 1161 and the ridge line 1162 of the other of the two first protrusions 1121 perpendicularly intersect the virtual straight line L 13 .
- the six second protrusions 1122 protrude from the surface 1101 .
- the second protrusions 1122 are farther from the load point P L than the first protrusions 1121 are.
- the second protrusion 1122 includes a top face 118 .
- the second protrusion 1122 includes a ridge line 1181 and a ridge line 1182 .
- the ridge line 1181 is located closer to the load point P L than the ridge line 1182 is.
- One of the six second protrusions 1122 is located at a position intersecting the virtual straight line L 11 .
- this second protrusion 1122 as illustrated in FIG. 11 , the ridge line 1181 and the ridge line 1182 perpendicularly intersect the virtual straight line L 11 .
- Two of the six second protrusions 1122 are located at positions intersecting the virtual straight line L 12 .
- the ridge line 1181 and the ridge line 1182 perpendicularly intersect the virtual straight line L 12 .
- One of the six second protrusions 1122 is located at a position intersecting the virtual straight line L 13 .
- this second protrusion 1122 as illustrated in FIG. 11 , the ridge line 1181 and the ridge line 1182 perpendicularly intersect the virtual straight line L 13 .
- Two of the six second protrusions 1122 are located at positions intersecting the virtual straight line L 14 .
- the ridge line 1181 and the ridge line 1182 perpendicularly intersect the virtual straight line L 14 .
- modes of the first protrusions 1121 and the second protrusions 1122 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the first protrusions 1121 and the second protrusions 1122 and the inclination angles ⁇ of the side faces forming the first protrusions 1121 and the second protrusions 1122 can be set in accordance with the magnitude of the assumed load.
- the widths of the top faces 114 , 116 , and 118 and the intervals between the first protrusions 1121 and the second protrusions 1122 can be set in accordance with the magnitude of the assumed load.
- the panel 110 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusions 1121 and the second protrusions 1122 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the first protrusions 1121 and the second protrusions 1122 may all be the same, or some or all may be different.
- the widths of the top faces 114 , 116 , and 118 may all be the same, or some or all may be different.
- the intervals between the first protrusions 1121 and the second protrusions 1122 may all be the same, or some or all may be different.
- the numbers of the first protrusions 1121 and the second protrusions 1122 can also be set in accordance with the magnitude of the assumed load.
- the panel 110 according to the sixth embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 13 is a plan view of the panel 120 .
- FIG. 14 is a XIV-XIV cross-sectional view of FIG. 13 .
- the panel 120 according to the seventh embodiment differs from the panel 10 of the first embodiment in a configuration of a plurality of protrusions 122 .
- the configuration of the protrusions 122 is mainly described below; description is given on differences from the protrusions 16 of the first embodiment.
- the protrusions 122 include a first protrusion 1221 , a plurality (two in the present embodiment) of second protrusions 1222 , and a plurality (four in the present embodiment) of third protrusions 1223 .
- the numbers of the second protrusions 1222 and the third protrusions 1223 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as in the panel 10 of the first embodiment.
- the first protrusion 1221 protrudes from a surface 1201 of the panel 120 .
- the first protrusion 1221 is formed concentrically with the load point P L of the panel 120 in a planar view.
- the first protrusion 1221 includes a top face 124 .
- the top face 124 has a regular octagonal shape in a planar view. As viewed from the thickness direction of the panel 120 , the center of the top face 124 coincides with the load point P L .
- the first protrusion 1221 includes a ridge line 1241 .
- the ridge line 1241 has a square shape in a planar view. As illustrated in FIG. 13 , the ridge line 1241 intersects the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly. Although not shown, the ridge line 1241 intersects all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by the ridge line 1241 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the two second protrusions 1222 each protrude from the surface 1201 .
- the two second protrusions 1222 are formed concentrically with respect to the load point P L .
- one of the two second protrusions 1222 that is closer to the load point P L will be called a first ring-shaped protrusion 126
- one of the two second protrusions 1222 that is farther from the load point P L will be called a second ring-shaped protrusion 128 .
- the first ring-shaped protrusion 126 includes a top face 130 .
- the top face 130 has a regular octagonal frame shape in a planar view.
- the first ring-shaped protrusion 126 includes a ridge line 1301 and a ridge line 1302 .
- the ridge line 1301 is located closer to the load point P L than the ridge line 1302 is.
- the ridge line 1301 and the ridge line 1302 each have a regular octagonal shape in a planar view.
- the ridge line 1301 and the ridge line 1302 intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the ridge line 1301 and the ridge line 1302 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge line 1301 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge line 1302 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the second ring-shaped protrusion 128 includes a top face 132 .
- the top face 132 has a regular octagonal frame shape in a planar view.
- the second ring-shaped protrusion 128 includes a ridge line 1321 and a ridge line 1322 .
- the ridge line 1321 is located closer to the load point P L than the ridge line 1322 is.
- the ridge line 1321 and the ridge line 1322 each have a regular octagonal shape in a planar view. As illustrated in FIG. 13 , the ridge line 1321 and the ridge line 1322 intersect the four virtual straight lines L 11 , L 12 , L 13 , and L 14 perpendicularly.
- the ridge line 1321 and the ridge line 1322 intersect all of the virtual straight lines extending radially from the load point P L at angles within a range of 45 to 90 degrees.
- acute angles out of angles formed by the ridge line 1321 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees
- acute angles out of angles formed by the ridge line 1322 and the virtual straight lines extending radially from the load point P L are within a range of 45 to less than 90 degrees.
- the third protrusions 1223 protrude from the surface 1201 .
- the third protrusions 1223 each have a substantially trapezoidal shape in a planar view.
- the third protrusions 1223 are farther from the load point P L than the second ring-shaped protrusion 128 is.
- the third protrusion 1223 includes a top face 134 .
- the top face 134 has a trapezoidal shape in a planar view.
- the ring-shaped third protrusion 1223 includes a ridge line 1341 and a ridge line 1342 .
- the ridge line 1341 is located closer to the load point P L than the ridge line 1342 is. As illustrated in FIG. 13 , the ridge line 1341 and the ridge line 1342 perpendicularly intersect one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- modes of the first protrusion 1221 , the second protrusions 1222 , and the third protrusions 1223 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the first protrusion 1221 , the second protrusions 1222 , and the third protrusions 1223 and the inclination angles ⁇ of the side faces forming the first protrusion 1221 , the second protrusions 1222 , and the third protrusions 1223 can be set in accordance with the magnitude of the assumed load.
- the widths of the top faces 124 , 130 , 132 , and 134 and the intervals between the first protrusion 1221 , the second protrusions 1222 , and the third protrusions 1223 can be set in accordance with the magnitude of the assumed load.
- the panel 120 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusion 1221 , the second protrusions 1222 , and the third protrusions 1223 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the first protrusion 1221 , the second protrusions 1222 , and the third protrusions 1223 may all be the same, or some or all may be different.
- the widths of the top faces 124 , 130 , 132 , and 134 may all be the same, or some or all may be different.
- the intervals between the first protrusion 1221 , the second protrusions 1222 , and the third protrusions 1223 may all be the same, or some or all may be different.
- the numbers of the second protrusions 1222 and the third protrusions 1223 can also be set in accordance with the magnitude of the assumed load.
- the panel 90 according to the seventh embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 15 is a plan view of the panel 140 .
- FIG. 16 is a XVI-XVI cross-sectional view of FIG. 15 .
- the panel 140 according to the eighth embodiment differs from the panel 10 of the first embodiment in a configuration of a plurality of protrusions 142 .
- the configuration of the protrusions 142 is mainly described below; description is given on differences from the protrusions 16 of the first embodiment.
- the starting point side is called one end in the circumferential direction
- the endpoint side is called the other end in the circumferential direction.
- the protrusions 142 include a first protrusion 1421 , a plurality (two in the present embodiment) of second protrusions 1422 , a plurality (two in the present embodiment) of third protrusions 1423 , a plurality (two in the present embodiment) of fourth protrusions 1424 , a plurality (two in the present embodiment) of fifth protrusions 1425 , a plurality (four in the present embodiment) of sixth protrusions 1426 , and a plurality (four in the present embodiment) of seventh protrusions 1427 .
- the numbers of the first protrusion 1421 to the seventh protrusions 1427 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point P L , as in the panel 10 of the first embodiment.
- the first protrusion 1421 is located on the load point P L .
- the first protrusion 1421 includes a top face 143 .
- the first protrusion 1421 includes a ridge line 1431 .
- the top face 143 and the ridge line 1431 each have a circular shape in a planar view. As viewed from the thickness direction of the panel 140 , the center of the top face 143 and the center of the ridge line 1431 coincide with the load point P L .
- the two second protrusions 1422 are located on a first circle whose center is the load point P L .
- the second protrusion 1422 includes a top face 144 .
- the second protrusion 1422 includes a ridge line 1441 and a ridge line 1442 .
- the ridge line 1441 is located closer to the load point P L than the ridge line 1442 is.
- the ridge line 1441 and the ridge line 1442 each have a midpoint located farther from the load point P L than the straight lines connecting both ends of the ridge line 1441 and the ridge line 1442 are.
- the ridge line 1441 and the ridge line 1442 each have an arc shape that is convex toward a direction going away from the load point P L in a planar view.
- the ridge line 1441 and the ridge line 1442 perpendicularly intersect two of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- One of the two second protrusions 1422 is called the second protrusion 1422 A, and the other is called the second protrusion 1422 B.
- One end part in the circumferential direction of the second protrusion 1422 A perpendicularly intersects the virtual straight line L 11 .
- the other end part in the circumferential direction of the second protrusion 1422 A perpendicularly intersects the virtual straight line L 12 .
- One end part in the circumferential direction of the second protrusion 1422 B perpendicularly intersects the virtual straight line L 13 .
- the other end part in the circumferential direction of the second protrusion 1422 B perpendicularly intersects the virtual straight line L 14 .
- the two third protrusions 1423 are located on a second circle whose center is the load point P L .
- the second circle has a larger diameter than the first circle.
- the third protrusion 1423 includes a top face 146 .
- the third protrusion 1423 includes a ridge line 1461 and a ridge line 1462 .
- the ridge line 1461 is located closer to the load point P L than the ridge line 1462 is.
- the ridge line 1461 and the ridge line 1462 each have a midpoint located farther from the load point P L than the straight lines connecting both ends of the ridge line 1461 and the ridge line 1462 are.
- the ridge line 1461 and the ridge line 1462 each have an arc shape that is convex toward a direction going away from the load point P L in a planar view. As illustrated in FIG. 15 , the ridge line 1461 and the ridge line 1462 perpendicularly intersect two of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- One of the two third protrusions 1423 is called the third protrusion 1423 A, and the other is called the third protrusion 1423 B.
- One end part in the circumferential direction of the third protrusion 1423 A perpendicularly intersects the virtual straight line L 14 .
- the other end part in the circumferential direction of the third protrusion 1423 A perpendicularly intersects the virtual straight line L 11 .
- One end part in the circumferential direction of the third protrusion 1423 B perpendicularly intersects the virtual straight line L 12 .
- the other end part in the circumferential direction of the third protrusion 1423 B perpendicularly intersects the virtual straight line L 13 .
- the one end part in the circumferential direction of the third protrusion 1423 A overlaps with the other end part in the circumferential direction of the second protrusion 1422 B.
- the other end part in the circumferential direction of the third protrusion 1423 A overlaps with the one end part in the circumferential direction of the second protrusion 1422 A.
- the one end part in the circumferential direction of the third protrusion 1423 B overlaps with the other end part in the circumferential direction of the second protrusion 1422 A.
- the other end part in the circumferential direction of the third protrusion 1423 B overlaps with the one end part in the circumferential direction of the second protrusion 1422 B.
- the two fourth protrusions 1424 are located on a third circle whose center is the load point P L .
- the third circle has a larger diameter than the second circle.
- the fourth protrusion 1424 includes a top face 148 .
- the fourth protrusion 1424 includes a ridge line 1481 and a ridge line 1482 .
- the ridge line 1481 is located closer to the load point P L than the ridge line 1482 is.
- the ridge line 1481 and the ridge line 1482 each have a midpoint located farther from the load point P L than the straight lines connecting both ends of the ridge line 1481 and the ridge line 1482 are.
- the ridge line 1481 and the ridge line 1482 each have an arc shape that is convex toward a direction going away from the load point P L in a planar view. As illustrated in FIG. 15 , the ridge line 1481 and the ridge line 1482 perpendicularly intersect two of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- One of the two fourth protrusions 1424 is called the fourth protrusion 1424 A, and the other is called the fourth protrusion 1424 B.
- One end part in the circumferential direction of the fourth protrusion 1424 A perpendicularly intersects the virtual straight line L 11 .
- the other end part in the circumferential direction of the second protrusion 1422 A perpendicularly intersects the virtual straight line L 12 .
- One end part in the circumferential direction of the fourth protrusion 1424 B perpendicularly intersects the virtual straight line L 13 .
- the other end part in the circumferential direction of the fourth protrusion 1424 B perpendicularly intersects the virtual straight line L 14 .
- the one end part in the circumferential direction of the fourth protrusion 1424 A overlaps with the other end part in the circumferential direction of the third protrusion 1423 A and the one end part in the circumferential direction of the second protrusion 1422 A.
- the other end part in the circumferential direction of the fourth protrusion 1424 A overlaps with the one end part in the circumferential direction of the third protrusion 1423 B and the other end part in the circumferential direction of the second protrusion 1422 A.
- the one end part in the circumferential direction of the fourth protrusion 1424 B overlaps with the other end part in the circumferential direction of the third protrusion 1423 B and the one end part in the circumferential direction of the second protrusion 1422 B.
- the other end part in the circumferential direction of the fourth protrusion 1424 B overlaps with the other end part in the circumferential direction of the third protrusion 1423 A and the one end part in the circumferential direction of the third protrusion 1423 B.
- the two fifth protrusions 1425 are located on a fourth circle whose center is the load point P L .
- the fourth circle has a larger diameter than the third circle.
- the fifth protrusion 1425 includes a top face 150 .
- the fifth protrusion 1425 includes a ridge line 1501 and a ridge line 1502 .
- the ridge line 1501 is located closer to the load point P L than the ridge line 1502 is.
- the ridge line 1501 and the ridge line 1502 each have a midpoint located farther from the load point P L than the straight lines connecting both ends of the ridge line 1501 and the ridge line 1502 are.
- the ridge line 1501 and the ridge line 1502 each have an arc shape that is convex toward a direction going away from the load point P L in a planar view. As illustrated in FIG. 15 , the ridge line 1501 and the ridge line 1502 perpendicularly intersect two of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- One of the two fifth protrusions 1425 is called the fifth protrusion 1425 A, and the other is called the fifth protrusion 1425 B.
- One end part in the circumferential direction of the fifth protrusion 1425 A perpendicularly intersects the virtual straight line L 14 .
- the other end part in the circumferential direction of the fifth protrusion 1425 A perpendicularly intersects the virtual straight line L 11 .
- One end part in the circumferential direction of the fifth protrusion 1425 B perpendicularly intersects the virtual straight line L 12 .
- the other end part in the circumferential direction of the fifth protrusion 1425 B perpendicularly intersects the virtual straight line L 13 .
- the one end part in the circumferential direction of the fifth protrusion 1425 A overlaps with the other end part in the circumferential direction of the fourth protrusion 1424 B, the one end part in the circumferential direction of the third protrusion 1423 A, and the other end part in the circumferential direction of the third protrusion 1423 B.
- the other end part in the circumferential direction of the fifth protrusion 1425 A overlaps with the one end part in the circumferential direction of the fourth protrusion 1424 A, the other end part in the circumferential direction of the third protrusion 1423 A, and the one end part in the circumferential direction of the second protrusion 1422 A.
- the one end part in the circumferential direction of the fifth protrusion 1425 B overlaps with the other end part in the circumferential direction of the fourth protrusion 1424 A, the one end part in the circumferential direction of the third protrusion 1423 B, and the other end part in the circumferential direction of the second protrusion 1422 A.
- the other end part in the circumferential direction of the fifth protrusion 1425 B overlaps with the one end part in the circumferential direction of the fourth protrusion 1424 B, the other end part in the circumferential direction of the third protrusion 1423 B, and the one end part in the circumferential direction of the second protrusion 1422 B.
- the four sixth protrusions 1426 are located on a fifth circle whose center is the load point P L .
- the fifth circle has a larger diameter than the fourth circle.
- the sixth protrusion 1426 includes a top face 152 .
- the sixth protrusion 1426 includes a ridge line 1521 and a ridge line 1522 .
- the ridge line 1521 is located closer to the load point P L than the ridge line 1522 is.
- the ridge line 1521 and the ridge line 1522 each have a midpoint located farther from the load point P L than the straight lines connecting both ends of the ridge line 1521 and the ridge line 1522 are.
- the ridge line 1521 and the ridge line 1522 each have an arc shape that is convex toward a direction going away from the load point P L in a planar view. As illustrated in FIG. 15 , the ridge line 1521 and the ridge line 1522 perpendicularly intersect one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- One end part in the circumferential direction of the sixth protrusion 1426 A out of the four sixth protrusions 1426 perpendicularly intersects the virtual straight line L 11 .
- the other end in the circumferential direction of the sixth protrusion 1426 A is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the one end part in the circumferential direction of the sixth protrusion 1426 A overlaps with the other end part in the circumferential direction of the fifth protrusion 1425 A, the one end part in the circumferential direction of the fourth protrusion 1424 A, the other end part in the circumferential direction of the third protrusion 1423 A, and the one end part in the circumferential direction of the second protrusion 1422 A.
- One end in the circumferential direction of the sixth protrusion 1426 B out of the four sixth protrusions 1426 is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the other end part in the circumferential direction of the sixth protrusion 1426 B perpendicularly intersects the virtual straight line L 12 .
- the other end part in the circumferential direction of the sixth protrusion 1426 B overlaps with the one end part in the circumferential direction of the fifth protrusion 1425 B, the other end part in the circumferential direction of the fourth protrusion 1424 A, the one end part in the circumferential direction of the third protrusion 1423 B, and the other end part in the circumferential direction of the second protrusion 1422 A.
- One end part in the circumferential direction of the sixth protrusion 1426 C out of the four sixth protrusions 1426 perpendicularly intersects the virtual straight line L 13 .
- the other end in the circumferential direction of the sixth protrusion 1426 C is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the one end part in the circumferential direction of the sixth protrusion 1426 C overlaps with the other end part in the circumferential direction of the fifth protrusion 1425 B, the one end part in the circumferential direction of the fourth protrusion 1424 B, the other end part in the circumferential direction of the third protrusion 1423 B, and the one end part in the circumferential direction of the second protrusion 1422 B.
- One end in the circumferential direction of the sixth protrusion 1426 D out of the four sixth protrusions 1426 is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the other end part in the circumferential direction of the sixth protrusion 1426 D perpendicularly intersects the virtual straight line L 14 .
- the other end part in the circumferential direction of the sixth protrusion 1426 D overlaps with the one end part in the circumferential direction of the fifth protrusion 1425 A, the other end part in the circumferential direction of the fourth protrusion 1424 B, the one end part in the circumferential direction of the third protrusion 1423 A, and the other end part in the circumferential direction of the second protrusion 1422 B.
- the four seventh protrusions 1427 are located on a sixth circle whose center is the load point P L .
- the sixth circle has a larger diameter than the fifth circle.
- the seventh protrusion 1427 includes a top face 154 .
- the seventh protrusion 1427 includes a ridge line 1541 and a ridge line 1542 .
- the ridge line 1541 is located closer to the load point P L than the ridge line 1542 is.
- the ridge line 1541 and the ridge line 1542 each have a midpoint located farther from the load point P L than the straight lines connecting both ends of the ridge line 1541 and the ridge line 1542 are.
- the ridge line 1541 and the ridge line 1542 each have an arc shape that is convex toward a direction going away from the load point P L in a planar view. As illustrated in FIG. 15 , the ridge line 1541 and the ridge line 1542 perpendicularly intersect one of the four virtual straight lines L 11 , L 12 , L 13 , and L 14 .
- One end in the circumferential direction of the seventh protrusion 1427 A out of the four seventh protrusions 1427 is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the other end part in the circumferential direction of the seventh protrusion 1427 A perpendicularly intersects the virtual straight line L 11 .
- the other end part in the circumferential direction of the seventh protrusion 1427 overlaps with the one end part in the circumferential direction of the sixth protrusion 1426 A, the other end part in the circumferential direction of the fifth protrusion 1425 A, the one end part in the circumferential direction of the fourth protrusion 1424 A, the other end part in the circumferential direction of the third protrusion 1423 A, and the one end part in the circumferential direction of the second protrusion 1422 A.
- One end part in the circumferential direction of the seventh protrusion 1427 B out of the four seventh protrusions 1427 perpendicularly intersects the virtual straight line L 12 .
- the other end in the circumferential direction of the seventh protrusion 1427 A is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the one end part in the circumferential direction of the seventh protrusion 1427 B overlaps with the other end part in the circumferential direction of the sixth protrusion 1426 B, the one end part in the circumferential direction of the fifth protrusion 1425 B, the other end part in the circumferential direction of the fourth protrusion 1424 A, the one end part in the circumferential direction of the third protrusion 1423 B, and the other end part in the circumferential direction of the second protrusion 1422 A.
- One end in the circumferential direction of the seventh protrusion 1427 C out of the four seventh protrusions 1427 is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the other end part in the circumferential direction of the seventh protrusion 1427 C perpendicularly intersects the virtual straight line L 13 .
- the other end part in the circumferential direction of the seventh protrusion 1427 C overlaps with the one end part in the circumferential direction of the sixth protrusion 1426 C, the other end part in the circumferential direction of the fifth protrusion 1425 B, the one end part in the circumferential direction of the fourth protrusion 1424 B, the other end part in the circumferential direction of the third protrusion 1423 B, and the one end part in the circumferential direction of the second protrusion 1422 B.
- One end part in the circumferential direction of the seventh protrusion 1427 D out of the four seventh protrusions 1427 perpendicularly intersects the virtual straight line L 14 .
- the other end in the circumferential direction of the seventh protrusion 1427 D is located at the boundary between the reinforced section 12 and the peripheral edge 14 .
- the one end part in the circumferential direction of the seventh protrusion 1427 D overlaps with the other end part in the circumferential direction of the sixth protrusion 1426 D, the one end part in the circumferential direction of the fifth protrusion 1425 A, the other end part in the circumferential direction of the fourth protrusion 1424 B, the one end part in the circumferential direction of the third protrusion 1423 A, and the other end part in the circumferential direction of the second protrusion 1422 B.
- modes of the first protrusion 1421 to the seventh protrusions 1427 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the first protrusion 1421 to the seventh protrusions 1427 and the inclination angles ⁇ of the side faces forming the first protrusion 1421 to the seventh protrusions 1427 can be set in accordance with the magnitude of the assumed load.
- the widths of the top faces 143 , 144 , 146 , 148 , 150 , 152 , and 154 and the intervals between the first protrusion 1421 to the seventh protrusions 1427 can be set in accordance with the magnitude of the assumed load.
- the panel 140 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusion 1421 to the seventh protrusions 1427 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the first protrusion 1421 to the seventh protrusions 1427 may all be the same, or some or all may be different.
- the widths of the top faces 143 , 144 , 146 , 148 , 150 , 152 , and 154 may all be the same, or some or all may be different.
- the intervals between the first protrusion 1421 to the seventh protrusions 1427 may all be the same, or some or all may be different.
- the numbers of the first protrusion 1421 to the seventh protrusions 1427 can also be set in accordance with the magnitude of the assumed load.
- the circumferential length of portions that overlap with each other is set appropriately, in accordance with surface rigidity against an assumed load applied to the load point P L .
- the circumferential length of the portions overlapping with each other may be the same for two adjacent protrusions close to the load point P L and two adjacent protrusions far away from the load point P L .
- edges of the end parts in the circumferential direction intersecting the virtual straight line L 11 may extend in a direction parallel to the virtual straight line L 11 .
- the circumferential length of the portions overlapping with each other may be larger for two adjacent protrusions far away from the load point P L than for two adjacent protrusions close to the load point P L .
- edges of the end parts in the circumferential direction intersecting the virtual straight line L 11 may extend in a direction passing through the load point P L and intersecting the virtual straight line L 11 .
- an angle ⁇ formed by one edge and the other edge is set appropriately in accordance with surface rigidity against an assumed load applied to the load point P L .
- the circumferential length of portions that overlap with each other can be configured as illustrated in FIG. 17 .
- the circumferential length of portions that overlap with each other can be configured as illustrated in FIG. 17 .
- the circumferential length of portions that overlap with each other can be configured as illustrated in FIG. 17 .
- the panel 140 according to the eighth embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 18 is a plan view of the panel 160 .
- FIG. 19 is a XVI-XVI cross-sectional view of FIG. 18 .
- the panel 160 according to the ninth embodiment differs from the panel 140 of the eighth embodiment in a configuration of a plurality of second protrusions 162 .
- the configuration of the second protrusions 162 is mainly described below; description is given on differences from the protrusions 142 of the eighth embodiment.
- the starting point side is called one end in the circumferential direction
- the endpoint side is called the other end in the circumferential direction.
- the panel 160 is obtained by adding, to the panel 140 of the eighth embodiment, a plurality (two in the present embodiment) of eighth protrusions 1621 , a plurality (two in the present embodiment) of ninth protrusions 1622 , a plurality (two in the present embodiment) of tenth protrusions 1623 , and a plurality (two in the present embodiment) of eleventh protrusions 1624 .
- the eighth protrusions 1621 protrude from a surface 1601 .
- the eighth protrusions 1621 each include a top face 164 .
- the top face 164 has a circular shape in a planar view.
- the eighth protrusions 1621 each include a ridge line 1641 .
- the ridge line 1641 has a circular shape in a planar view.
- the eighth protrusions 1621 are located on the first circle.
- the eighth protrusions 1621 are located between the two second protrusions 1422 adjacent to each other in the circumferential direction.
- the ninth protrusions 1622 protrude from the surface 1601 .
- the ninth protrusions 1622 each include a top face 166 .
- the top face 166 has a circular shape in a planar view.
- the ninth protrusions 1622 each include a ridge line 1661 .
- the ridge line 1661 has a circular shape in a planar view.
- the ninth protrusions 1622 are located on the second circle.
- the ninth protrusions 1622 are located between the two third protrusions 1423 adjacent to each other in the circumferential direction.
- the tenth protrusions 1623 protrude from the surface 1601 .
- the tenth protrusions 1623 each include a top face 168 .
- the top face 168 has a circular shape in a planar view.
- the tenth protrusions 1623 each include a ridge line 1681 .
- the ridge line 1681 has a circular shape in a planar view.
- the tenth protrusions 1623 are located on the third circle.
- the tenth protrusions 1623 are located between the two fourth protrusions 1424 adjacent to each other in the circumferential direction.
- the eleventh protrusions 1624 protrude from the surface 1601 .
- the eleventh protrusions 1624 each include a top face 170 .
- the top face 170 has a circular shape in a planar view.
- the eleventh protrusions 1624 each include a ridge line 1701 .
- the ridge line 1701 has a circular shape in a planar view.
- the eleventh protrusions 1624 are located on the fourth circle.
- the eleventh protrusions 1624 are located between the two fifth protrusions 1425 adjacent to each other in the circumferential direction.
- modes of the first protrusion 1421 to the eleventh protrusions 1624 are set in consideration of surface rigidity against an assumed load applied to the load point P L . That is, as in the panel 10 according to the first embodiment, the heights of the first protrusion 1421 to the eleventh protrusions 1624 and the inclination angles ⁇ of the side faces forming the first protrusion 1421 to the eleventh protrusions 1624 can be set in accordance with the magnitude of the assumed load.
- the widths of the top faces 143 , 144 , 146 , 148 , 150 , 152 , 154 , 164 , 166 , 168 , and 170 and the intervals between the first protrusion 1421 to the eleventh protrusions 1624 can be set in accordance with the magnitude of the assumed load.
- the panel 160 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the first protrusion 1421 to the eleventh protrusions 1624 may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the first protrusion 1421 to the eleventh protrusions 1624 may all be the same, or some or all may be different.
- the widths of the top faces 143 , 144 , 146 , 148 , 150 , 152 , 154 , 164 , 166 , 168 , and 170 may all be the same, or some or all may be different.
- the intervals between the first protrusion 1421 to the eleventh protrusions 1624 may all be the same, or some or all may be different.
- the numbers of the second protrusions 1422 to the eleventh protrusions 1624 can also be set in accordance with the magnitude of the assumed load.
- the panel 160 according to the ninth embodiment described above provides an effect similar to that of the panel 10 of the first embodiment.
- FIG. 20 is a plan view of the panel 2000 .
- the panel 2000 according to the tenth embodiment includes a plurality of load points P L 1 and P L 2 .
- Provided around each of the load points P L 1 and P L 2 are protrusions intersecting, at a plurality of positions, each of a plurality of virtual straight lines extending radially from the corresponding load points P L 1 and P L 2 .
- description will be given using as an example the panel 2000 including, as the protrusions, the protrusions 16 formed on the panel 10 according to the first embodiment.
- the panel 2000 has a rectangular shape in a planar view.
- the panel 2000 has the load point PO at the center of a left-half region 2000 L and the load point P L 2 at the center of a right-half region 2000 R.
- the left-half region 2000 L of the panel 2000 is provided with protrusions 16 L formed around the load point P L 1 .
- the protrusions 16 L include a first protrusion 161 L, second protrusions 162 L, and third protrusions 163 L.
- the right-half region 2000 R of the panel 2000 is provided with protrusions 16 R formed around the load point P L 2 .
- the protrusions 16 R include a first protrusion 161 R, second protrusions 162 R, and third protrusions 163 R.
- top faces 38 L and 38 R, side faces 40 L and 40 R, and side faces 42 L and 42 R of the third protrusions 163 L and 163 R and the surfaces 101 on the left and right are continuous.
- a spot where the side faces 40 L and 40 R or the side faces 42 L and 42 R are connected is formed with an acute angle.
- a spot where the side faces 40 L and 40 R or the side faces 42 L and 42 R are connected may be provided with a curved surface to make the side faces 40 L and 40 R or the side faces 42 L and 42 R continuous via the curved surface.
- modes of the protrusions 16 L and 16 R are set in consideration of surface rigidity against an assumed load applied to each of the load points P L 1 and P L 2 . That is, as in the panel 10 according to the first embodiment, the heights of the protrusions 16 L and 16 R and the inclination angles ⁇ of the side faces forming the protrusions 16 L and 16 R can be set in accordance with the magnitude of the assumed load. In addition, as in the panel 10 according to the first embodiment, the widths of the top faces of the protrusions 16 L and 16 R and the intervals between the protrusions 16 L and 16 R can be set in accordance with the magnitude of the assumed load. Thus, the panel 2000 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield.
- the heights of the protrusions 16 L and 16 R may all be the same, or some or all may be different.
- the inclination angles ⁇ of the side faces forming the protrusions 16 L and 16 R may all be the same, or some or all may be different.
- the widths of the top faces of the protrusions 16 L and 16 R may all be the same, or some or all may be different.
- the intervals between the protrusions 16 L and 16 R may all be the same, or some or all may be different.
- the numbers of the second protrusions 162 L and 162 R and the third protrusions 163 L and 163 R can also be set in accordance with the magnitude of the assumed load.
- the panel 2000 according to the tenth embodiment described above provides an effect similar to that of the panel 10 of the first embodiment even in the case where a load is applied to a plurality of positions of the panel 2000 from the outside.
- surface rigidity can be improved appropriately against an assumed load applied to each of the load points P L 1 and P L 2 .
- the shapes of the protrusions 16 L and 16 R in the panel 2000 according to the present embodiment are not limited to circular shapes. Instead of the shapes of the protrusions 16 in the panel 10 of the first embodiment, the shapes of the protrusions in the panel of any of the second to ninth embodiments may be used.
- the shapes of the protrusions formed in the left-half region 2000 L may be the same as or different from the shapes of the protrusions formed in the right-half region 2000 R.
- the protrusions 16 L and 16 R formed around the corresponding load points P L 1 and P L 2 have the same cross-sectional shapes, density, and formation range in the panel 2000 according to the present embodiment, but the cross-sectional shapes, density, and formation range may be changed between the protrusions 16 L and 16 R in accordance with an assumed load applied to each of the load points P L 1 and P L 2 .
- the cross-sectional shapes, density, and formation range may be changed between the protrusions 16 L and 16 R in accordance with an assumed load applied to each of the load points P L 1 and P L 2 .
- FIG. 22 is a plan view of the panel 2100 .
- the ranges of left and right regions 2100 L and 2100 R that is, the formation ranges of the protrusions 16 L and 16 R, are different. Description is given below on differences from the panel 2000 of the tenth embodiment.
- the panel 2100 according to the present embodiment is an example of a panel in which an assumed load applied to the load point P L 1 is larger than an assumed load applied to the load point P L 2 .
- the formation range of the protrusions 16 L formed around the load point P L 1 is made larger than the formation range of the protrusions 16 R formed around the load point P L 2 so that surface rigidity against a load applied to the load point P L 1 is relatively large.
- end parts of the second protrusion 162 R of the protrusions 16 R are formed so as to prevent interference between the protrusions 16 L and 16 R.
- the formation ranges of the protrusions 16 L and 16 R are set in consideration of surface rigidity against an assumed load applied to each of the load points P L 1 and P L 2 , and the formation range of the protrusions 16 L formed around the load point P L 1 with a larger assumed load is made larger. In this manner, surface rigidity centered at the load point P L 1 can be improved relatively, and thus surface rigidity can be improved appropriately against an assumed load applied to each of the load points P L 1 and P L 2 .
- the formation ranges of the protrusions 16 L and 16 R are set in accordance with an assumed load applied to each of the load points P L 1 and P L 2 .
- the formation ranges of the protrusions 16 L and 16 R may be changed in accordance with assumed loads.
- the shapes of the protrusions 16 L and 16 R in the panel 2100 according to the present embodiment are not limited to circular shapes. Instead of the shapes of the protrusions 16 in the panel 10 of the first embodiment, the shapes of the protrusions in the panel of any of the second to ninth embodiments may be used.
- the shapes of the protrusions formed in the left-half region 2100 L may be the same as or different from the shapes of the protrusions formed in the right-half region 2100 R.
- FIG. 24 is a plan view of the panel 2300 .
- the protrusions 16 L and 16 R formed in left and right regions 2300 L and 2300 R, respectively, have different densities. Description is given below on differences from the panel 2000 of the twelfth embodiment.
- the panel 2300 according to the present embodiment is an example of a panel in which an assumed load applied to the load point P L 1 is larger than an assumed load applied to the load point P L 2 .
- the density of the protrusions 16 L formed around the load point P L 1 is made higher than the density of the protrusions 16 R formed around the load point P L 2 so that surface rigidity against a load applied to the load point P L 1 is relatively large.
- the position of the boundary portion B is set such that the top faces 38 L and 38 R, side faces 40 L and 40 R, and side faces 42 L and 42 R of the third protrusions 163 L and 163 R and the surfaces 101 on the left and right are continuous.
- the densities of the protrusions 16 L and 16 R are set in consideration of surface rigidity against an assumed load applied to each of the load points P L 1 and P L 2 , and the density of the protrusions 16 L formed around the load point P L 1 with a larger assumed load is made higher. In this manner, surface rigidity centered at the load point P L 1 can be improved relatively, and thus surface rigidity can be improved appropriately against an assumed load applied to each of the load points P L 1 and P L 2 .
- the shapes of the protrusions 16 L and 16 R in the panel 2300 according to the present embodiment are not limited to circular shapes. Instead of the shapes of the protrusions 16 in the panel 10 of the first embodiment, the shapes of the protrusions in the panel of any of the second to ninth embodiments may be used.
- the shapes of the protrusions formed in the left-half region 2300 L may be the same as or different from the shapes of the protrusions formed in the right-half region 2300 R.
- the formation ranges of the protrusions 16 L and 16 R may be set in accordance with assumed loads.
- the widths of the top faces of the protrusions were 2 mm
- the inclination angles ⁇ of the side faces of the protrusions with respect to the surface of the panel were 45 degrees
- the interval between two protrusions adjacent to each other in a direction from the range of load application (load point) toward the outer side was 10 mm
- the depth of protrusions and recesses was 3 mm.
- the diameter of the top face of the protrusion located on the load point P L was set to 3 mm.
- the length of one side of the top face of the protrusion located on the load point P L was set to 6 mm.
- the angle ⁇ shown in FIG. 17 was set to 30 degrees.
- the panel 180 according to Comparative Example 1 has a protrusion 182 , as illustrated in FIG. 25 .
- FIG. 25 is an explanatory diagram illustrating the shape of a top face of the protrusion 182 .
- an inclined surface is formed at an edge portion of the protrusion 182 .
- the protrusion 182 is hatched in FIG. 25 .
- An inclination angle of the inclined surface with respect to a surface 1801 of the panel 180 was 45 degrees.
- the protrusion height of the protrusion 182 from the surface 1801 was 3 mm.
- a dimension D 1 was 24 mm.
- a dimension D 2 was 40 mm.
- a dimension D 3 was 8 mm.
- a dimension D 4 was 8 mm.
- a dimension D 5 was 8 mm.
- a dimension D 6 was 24 mm.
- a dimension D 7 was 20 mm.
- a dimension D 8 was 24 mm.
- a dimension D 9 was 3 mm.
- a dimension D 10 was 3 mm.
- a dimension D 11 was 15 mm.
- a dimension D 12 was 24 mm.
- a dimension D 13 was 3 mm.
- a dimension D 14 was 8 mm.
- a dimension D 15 was 24 mm.
- a dimension D 16 was 40 mm.
- the panel 190 according to Comparative Example 2 has a protrusion 192 , as illustrated in FIG. 26 .
- FIG. 26 is an explanatory diagram illustrating the shape of a top face of the protrusion 192 .
- an inclined surface is formed at an edge portion of the protrusion 192 .
- the protrusion 192 is hatched in FIG. 26 .
- An inclination angle of the inclined surface with respect to a surface 1901 of the panel 190 was 45 degrees.
- the protrusion height of the protrusion 192 from the surface 1901 was 3 mm.
- a dimension D 1 was 24 mm.
- a dimension D 2 was 40 mm.
- a dimension D 3 was 8 mm.
- a dimension D 4 was 3 mm.
- a dimension D 5 was 11 mm.
- a dimension D 6 was 24 mm.
- a dimension D 7 was 18 mm.
- a dimension D 8 was 40 mm.
- a dimension D 9 was 48 mm.
- a dimension D 10 was 3 mm.
- a dimension D 11 was 18 mm.
- a dimension D 12 was 12 mm.
- FIGS. 27 to 30 show the analysis results.
- FIG. 27 is a graph showing the results when the range of load application had a 20-mm-square square shape.
- FIG. 28 is a graph showing the results when the range of load application had a 50-mm-square square shape.
- FIG. 29 is a graph showing the results when the range of load application had a 100-mm-square square shape.
- FIG. 30 is a graph showing the results when the range of load application had a 150-mm-square square shape.
- the vertical axis indicates the rate of increase in surface rigidity relative to a flat plate.
- the rate of increase was determined in the following manner. First, displacement when a load was applied to the flat plate was calculated in the manner as described above. Then, the displacement when a load was applied to the flat plate was divided by displacement when a load was applied to the panel with a protrusion; thus, the rate of increase was determined.
- Examples 1 to 9 exhibited improved surface rigidity as compared with Comparative Examples 1 and 2.
- Examples 1, 3, and 6 to 9 exhibited improved surface rigidity as compared with Examples 2, 4, and 5.
- a larger number of ridge lines that perpendicularly intersect the virtual straight lines extending radially from the load point P L resulted in more improved surface rigidity.
- Surface rigidity was improved when there existed a ridge line that perpendicularly intersects a straight line connecting the load point P L and a vertex of the panel.
- FIGS. 31 to 34 show the analysis results.
- FIG. 31 is a graph showing the results when the range of load application had a 20-mm-square square shape.
- FIG. 32 is a graph showing the results when the range of load application had a 50-mm-square square shape.
- FIG. 33 is a graph showing the results when the range of load application had a 100-mm-square square shape.
- FIG. 34 is a graph showing the results when the range of load application had a 150-mm-square square shape.
- the panel need not have a peripheral edge for attaching the panel to another member, around a region where the protrusions are formed (the reinforced section in the above embodiments).
- the region where the protrusions are formed may be formed on a flat surface, or may be formed on a curved surface. A portion where a ridge line is formed may be subjected to filleting.
- the above embodiments illustrate modes in which a plurality of protrusions are arranged at regular intervals in a predetermined cross section passing through the load point P L .
- a plurality of protrusions are arranged at regular intervals in a predetermined cross section passing through the load point P L as in these embodiments.
- the intervals between the protrusions may differ entirely or partially in the panel as long as characteristics required of the panel are allowed.
- the protrusions may be partially chipped as long as characteristics required of the panel are allowed.
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Abstract
To provide a panel whose surface rigidity can be improved appropriately in accordance with a load. Provided is a panel including: a load point to which a load is applied from the outside; and a protrusion that protrudes from a surface of the panel and is formed continuously or discontinuously around the load point. The protrusion intersects, at a plurality of positions, each of a plurality of virtual straight lines extending radially from the load point.
Description
- This application is a Divisional of copending U.S. application Ser. No. 15/116,705, filed on Aug. 4, 2016, which is the National Phase under 35 U.S.C. § 371 of International Application No. PCT/JP2015/057467, filed on Mar. 13, 2015, which claims the benefit under 35 U.S.C. § 119(a) to Patent Application No. 2014-052405, filed in Japan on Mar. 14, 2014, all of which are hereby expressly incorporated by reference in their entirety into the present application.
- The present invention relates to a panel, particularly to a panel having a load point to which a load is applied from the outside.
- In recent years, panels used for automobiles and the like are required to be reduced in weight. An example of a method for weight reduction is to reduce sheet thickness. A reduction in sheet thickness, however, causes a problem in that rigidity is lowered. Hence, to ensure rigidity without increasing sheet thickness, forming protrusions and recesses in a panel is proposed. The protrusions and recesses are required to be formed with a depth as small as possible in order to suppress interference with other components.
- JP 5218633B discloses a panel having a plurality of protrusions and a plurality of recesses. Each protrusion has a flat top face. Each recess has a flat bottom face. The protrusions and the recesses are alternately arranged in rows and columns.
- JP 2012-148290A discloses a sheet material having protrusions and recesses. In this sheet material, many imaginary squares are combined vertically and horizontally to form a sheet surface, and the sheet surface has a protrusion-and-recess pattern. A basic configuration, where first and second regions are formed in the imaginary square, and more than one of various basic configurations derived from the basic configuration are butted together at their peripheral edges such that the first regions are butted together and the second regions are butted together; thus, an entire configuration of the sheet surface is obtained. The sheet material is configured in a manner that the protrusion-and-recess pattern is formed over the entire sheet surface by upwardly raising the first regions and downwardly recessing the second regions.
- JP 2009-286249A discloses a floor panel provided with a protrusion. In the protrusion, triangular flat surfaces are combined to have an angle. A flat surface is formed around the protrusion.
- JP 2006-297966A discloses a floor structure of a vehicle body. This floor structure includes a floor panel. The floor panel is provided with beads. The beads have a concentric arc shape whose center is a portion where a side sill and a cross-member intersect each other.
- Patent Literature 1: JP 5218633B
- Patent Literature 2: JP 2012-148290A
- Patent Literature 3: JP 2009-286249A
- Patent Literature 4: JP 2006-297966A
- The above panels include a panel on which a heavy object is placed, such as a floor panel of an automobile. Such a panel needs high surface rigidity. Here, surface rigidity indicates a degree to which a surface can withstand, without bending, a force pressing the surface. The present inventors studied the surface rigidity of the panels having protrusions and recesses described in the above cited literatures. The results revealed that none of the panels were adequate in improving surface rigidity. Specifically, since the protrusions and recesses formed in the panels described in the above cited literatures are not designed in consideration of a point to which a load is applied, improvement in surface rigidity is not adequate.
- The present invention has been made in view of the above problem, and an object of the present invention is to provide a panel whose surface rigidity can be improved appropriately in accordance with a load.
- According to an aspect of the present invention in order to achieve the above-mentioned object, there is provided a panel including: a load point to which a load is applied from the outside; and a protrusion that protrudes from a surface of the panel and is formed continuously or discontinuously around the load point. The protrusion intersects, at a plurality of positions, each of a plurality of virtual straight lines extending radially from the load point.
- The load point may be a junction with another member.
- The panel may include a plurality of the load points. At least one of density, a formation range, and a cross-sectional shape of the protrusion may differ in accordance with an assumed load applied to the load point.
- At a boundary portion where the protrusions formed around the corresponding plurality of load points intersect each other, side faces of the protrusions may be continuous via a curved surface.
- A ridge line of the protrusion may perpendicularly intersect the plurality of virtual straight lines.
- The plurality of virtual straight lines may be straight lines connecting the load point and a plurality of vertices of the panel.
- The protrusion may include a top face parallel to the surface of the panel.
- The protrusion may include a plurality of ring-shaped protrusions formed concentrically. The center of the ring-shaped protrusion may coincide with the load point.
- The protrusion may include a spiral-shaped protrusion whose base point is the load point.
- The panel may be made of a steel sheet.
- The panel may be a floor panel of an automobile.
- According to a panel of the present invention, surface rigidity can be improved appropriately in accordance with a load.
-
FIG. 1 is a plan view of a panel according to a first embodiment. -
FIG. 2 is a II-II cross-sectional view ofFIG. 1 . -
FIG. 3 is a plan view of a panel according to a second embodiment. -
FIG. 4 is a IV-IV cross-sectional view ofFIG. 3 . -
FIG. 5 is a plan view of a panel according to a third embodiment. -
FIG. 6 is a VI-VI cross-sectional view ofFIG. 5 . -
FIG. 7 is a plan view of a panel according to a fourth embodiment. -
FIG. 8 is a VIII-VIII cross-sectional view ofFIG. 7 . -
FIG. 9 is a plan view of a panel according to a fifth embodiment. -
FIG. 10 is a X-X cross-sectional view ofFIG. 9 . -
FIG. 11 is a plan view of a panel according to a sixth embodiment. -
FIG. 12 is a XII-XII cross-sectional view ofFIG. 11 . -
FIG. 13 is a plan view of a panel according to a seventh embodiment. -
FIG. 14 is a XIV-XIV cross-sectional view ofFIG. 13 . -
FIG. 15 is a plan view of a panel according to an eighth embodiment. -
FIG. 16 is a XVI-XVI cross-sectional view ofFIG. 15 . -
FIG. 17 is a plan view for describing circumferential lengths of protrusions. -
FIG. 18 is a plan view of a panel according to a ninth embodiment. -
FIG. 19 is a XVI-XVI cross-sectional view ofFIG. 17 . -
FIG. 20 is a plan view of a panel according to a tenth embodiment. -
FIG. 21 is an explanatory diagram illustrating a modification of the tenth embodiment. -
FIG. 22 is a plan view of a panel according to an eleventh embodiment. -
FIG. 23 is an explanatory diagram illustrating a modification of the eleventh embodiment. -
FIG. 24 is a plan view of a panel according to a twelfth embodiment. -
FIG. 25 is a conceptual diagram illustrating a protrusion of a panel according to Comparative Example 1. -
FIG. 26 is a conceptual diagram illustrating a protrusion of a panel according to Comparative Example 2. -
FIG. 27 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 20-mm-square square shape. -
FIG. 28 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 50-mm-square square shape. -
FIG. 29 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 100-mm-square square shape. -
FIG. 30 is a graph showing results of FEM analysis of surface rigidity for Comparative Examples 1 and 2 and Examples 1 to 9, and shows the results when a range of load application has a 150-mm-square square shape. -
FIG. 31 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 20-mm-square square shape. -
FIG. 32 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 50-mm-square square shape. -
FIG. 33 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 100-mm-square square shape. -
FIG. 34 is a graph showing results of FEM analysis of surface rigidity for Comparative Example 1, Example 1, and Example 8, and shows the results when a range of load application has a 150-mm-square square shape. - Hereinafter, (a) preferred embodiment(s) of the present invention will be described in detail with reference to the appended drawings. In this specification and the drawings, elements that have substantially the same function and structure are denoted with the same reference signs, and repeated explanation is omitted. Note that, in this description and the drawings, structural elements that have substantially the same function and structure are sometimes distinguished from each other using different alphabets after the same reference sign. However, when there is no need in particular to distinguish structural elements that have substantially the same function and structure, the same reference sign alone is attached.
- A
panel 10 according to a first embodiment will be described with reference toFIGS. 1 and 2 .FIG. 1 is a plan view of thepanel 10.FIG. 2 is a II-II cross-sectional view ofFIG. 1 . - The
panel 10 has a square shape in a planar view. In other words, thepanel 10 has, in a planar view, four vertices V11, V12, V13, and V14 and four sides S11, S12, S13, and S14. The side S11 connects the vertex V11 and the vertex V12. The side S12 connects the vertex V12 and the vertex V13. The side S13 connects the vertex V13 and the vertex V14. The side S14 connects the vertex V14 and the vertex V11. Thispanel 10 includes a load point PL, a reinforcedsection 12, and aperipheral edge 14. - The
panel 10 is, for example, a support plate that supports a heavy object. Specific examples are a floor panel for an automobile, a trunk lid inner panel, a floor for a building material, a support plate used for a copying machine or a refrigerator, and a casing of an attache case. A material of thepanel 10 may be, for example, a metal (e.g., steel, aluminum alloy, titanium, or stainless steel) or a synthetic resin. In the case where thepanel 10 is made of a metal, thepanel 10 is produced by press working, for example. Improving the formability of thepanel 10 by heating, as in warm forming or hot stamping, facilitates forming by press working. In the case where thepanel 10 is made of a synthetic resin, thepanel 10 is produced by injection molding, for example. - The reinforced
section 12 as a whole has, in a planar view, a square shape one size smaller than that of thepanel 10. Theperipheral edge 14 is formed around the reinforcedsection 12. Thepanel 10 is attached to another member at theperipheral edge 14. Specifically, for example, thepanel 10 is attached to another member at positions of theperipheral edge 14 that correspond to the four corners of thepanel 10. - The reinforced
section 12 is provided with a plurality ofprotrusions 16 around the load point PL. The plurality ofprotrusions 16 include afirst protrusion 161, a plurality (two in the present embodiment) ofsecond protrusions 162, and a plurality (four in the present embodiment) ofthird protrusions 163. Note that the numbers of thesecond protrusions 162 and thethird protrusions 163 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. - The planar shape of the
panel 10 is not particularly limited, and may be any of various shapes. The planar shape of thepanel 10 may be, instead of a square, a rectangle or a rectangle having one of its four corners cut off. - The load point PL indicates a position where a load is applied to the
panel 10 from the outside. In this specification, a load applied to thepanel 10 means a load that is applied to thepanel 10 from a direction intersecting a plane along which thepanel 10 extends. Accordingly, the load point PL does not include a position where a load is applied to thepanel 10 from a direction along the plane along which thepanel 10 extends. - The load point PL is typically configured as a junction with another member. For example, in the case where the
panel 10 is a floor panel of a vehicle, a joint position of a support member on which a seat in a cabin is placed may serve as the load point PL. In such an example, the load point PL of the floor panel is provided with a tapped hole, and the support member is joined to the floor panel with a bolt, etc. Thus, in the floor panel, a load is applied to the load point PL. - A method for joining another member to the load point PL of the
panel 10 is not limited to the method using a bolt, etc., and may be joining by welding or joining by using an adhesive. Moreover, another member need not be joined to the load point PL of thepanel 10. For example, thepanel 10 and another member may come into contact at the load point PL to cause a load to be applied to the load point PL. - The
first protrusion 161 protrudes from asurface 101 of thepanel 10. Thepanel 10 has, at a position where thefirst protrusion 161 is formed, a recess opening toward the rear surface side. The recess has a shape corresponding to thefirst protrusion 161. Thefirst protrusion 161 is formed concentrically with the load point PL of thepanel 10 in a planar view. Thefirst protrusion 161 includes atop face 18 and aside face 20. - The
top face 18 has a circular shape in a planar view. As viewed from the thickness direction of thepanel 10, the center of thetop face 18 coincides with the load point PL. Thetop face 18 is away from thesurface 101 in the thickness direction of thepanel 10. Thetop face 18 is parallel to thesurface 101. The protrusion height of thefirst protrusion 161, i.e., the distance between thetop face 18 and thesurface 101 in the thickness direction of thepanel 10, is 0.5 to 50 mm, for example. The protrusion height of thefirst protrusion 161 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. - The side face 20 has a circular ring shape in a planar view. The inner circumferential edge of the
side face 20 is farther from thesurface 101 than the outer circumferential edge of theside face 20 is. The inner circumferential edge of theside face 20 is connected to the edge of thetop face 18. The outer circumferential edge of theside face 20 is connected to thesurface 101. Surface rigidity increases as an inclination angle θ of theside face 20 with respect to thesurface 101 becomes larger. However, local sheet thickness reduction or cracking becomes more likely to occur during forming as the inclination angle θ of theside face 20 with respect to thesurface 101 becomes larger. The inclination angle θ is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. On that occasion, ease of forming of a material may also be taken into consideration. In the case of a steel material, the inclination angle θ is preferably 15 to 60 degrees, further preferably 45 degrees. - A
ridge line 181 formed as the boundary between thetop face 18 and theside face 20 has a circular shape in a planar view. As illustrated inFIG. 1 , theridge line 181 intersects four virtual straight lines L11, L12, L13, and L14 perpendicularly. The virtual straight line L11 connects the load point PL and the vertex V11 in a planar view. The virtual straight line L12 connects the load point PL and the vertex V12 in a planar view. The virtual straight line L13 connects the load point PL and the vertex V13 in a planar view. The virtual straight line L14 connects the load point PL and the vertex V14 in a planar view. In other words, the four virtual straight lines L11, L12, L13, and L14 extend radially from the load point PL. Although not shown, theridge line 181 perpendicularly intersects all of the virtual straight lines extending radially from the load point PL. - The two
second protrusions 162 each protrude from thesurface 101. The twosecond protrusions 162 each have a circular ring shape in a planar view. The twosecond protrusions 162 are formed concentrically with respect to the load point PL. Thepanel 10 has, at a position where thesecond protrusion 162 is formed, a recess opening toward the rear surface side. The recess has a shape corresponding to thesecond protrusion 162. Hereinafter, one of the twosecond protrusions 162 that is closer to the load point PL will be called a first ring-shapedprotrusion 22, and one of the twosecond protrusions 162 that is farther from the load point PL will be called a second ring-shapedprotrusion 24. - The first ring-shaped
protrusion 22 includes atop face 26, aside face 28, and aside face 30. Thetop face 26 has a circular ring shape in a planar view. The inner diameter of thetop face 26 is larger than the diameter of thetop face 18. As viewed from the thickness direction of thepanel 10, the center of thetop face 26 coincides with the load point PL. Thetop face 26 is away from thesurface 101 in the thickness direction of thepanel 10. Thetop face 26 is parallel to thesurface 101. The protrusion height of the first ring-shapedprotrusion 22, i.e., the distance between thetop face 26 and thesurface 101 in the thickness direction of thepanel 10, is 0.5 to 50 mm, for example. The protrusion height of the first ring-shapedprotrusion 22 may be the same as or different from the protrusion height of thefirst protrusion 161. The protrusion height of the first ring-shapedprotrusion 22 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. - The side face 28 is located closer to the load point PL than the
top face 26 is. The side face 28 has a circular ring shape in a planar view. The outer circumferential edge of theside face 28 is farther from thesurface 101 than the inner circumferential edge of theside face 28 is. The inner circumferential edge of theside face 28 is connected to thesurface 101. The outer circumferential edge of theside face 28 is connected to the inner circumferential edge of thetop face 26. An inclination angle θ of theside face 28 with respect to thesurface 101 is set similarly to the inclination angle θ of theside face 20. The inclination angle θ of theside face 28 with respect to thesurface 101 may be the same as or different from the inclination angle θ of theside face 20. The inclination angle θ of theside face 28 with respect to thesurface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. On that occasion, the distance from the load point PL and ease of forming of a material may also be taken into consideration. - A
ridge line 261 formed as the boundary between thetop face 26 and theside face 28 has a circular shape in a planar view. Theridge line 261 has a larger diameter than theridge line 181. As illustrated inFIG. 1 , theridge line 261 intersects the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 261 perpendicularly intersects all of the virtual straight lines extending radially from the load point PL. - The side face 30 is farther from the load point PL than the
top face 26 is. The side face 30 has a circular ring shape in a planar view. The inner circumferential edge of theside face 30 is farther from thesurface 101 than the outer circumferential edge of theside face 30 is. The inner circumferential edge of theside face 30 is connected to the outer circumferential edge of thetop face 26. The outer circumferential edge of theside face 30 is connected to thesurface 101. An inclination angle θ of theside face 30 with respect to thesurface 101 is set similarly to the inclination angle θ of theside face 20. The inclination angle θ of theside face 30 with respect to thesurface 101 may be the same as or different from the inclination angles θ of theside face 20 and theside face 28. The inclination angle θ of theside face 30 with respect to thesurface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. On that occasion, the distance from the load point PL and ease of forming of a material may also be taken into consideration. - A
ridge line 262 formed as the boundary between thetop face 26 and theside face 30 has a circular shape in a planar view. Theridge line 262 has a larger diameter than theridge line 261. As illustrated inFIG. 1 , theridge line 262 intersects the four virtual straight lines L11, L12, L13, and L14 perpendicularly. The distance between theridge line 262 and theridge line 261, i.e., the width of thetop face 26, is 0.5 to 50 mm, for example. Although not shown, theridge line 262 perpendicularly intersects all of the virtual straight lines extending radially from the load point PL. - The second ring-shaped
protrusion 24 includes atop face 32, aside face 34, and aside face 36. Thetop face 32 has a circular ring shape in a planar view. As viewed from the thickness direction of thepanel 10, the center of thetop face 32 coincides with the load point PL. Thetop face 32 is away from thesurface 101 in the thickness direction of thepanel 10. Thetop face 32 is parallel to thesurface 101. The protrusion height of the second ring-shapedprotrusion 24, i.e., the distance between thetop face 32 and thesurface 101 in the thickness direction of thepanel 10, is 0.5 to 50 mm, for example. The protrusion height of the second ring-shapedprotrusion 24 may be the same as or different from the protrusion heights of thefirst protrusion 161 and the first ring-shapedprotrusion 22. The protrusion height of the second ring-shapedprotrusion 24 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. - The side face 34 is located closer to the load point PL than the
top face 32 is. The side face 34 has a circular ring shape in a planar view. The outer circumferential edge of theside face 34 is farther from thesurface 101 than the inner circumferential edge of theside face 34 is. The inner circumferential edge of theside face 34 is connected to thesurface 101. The outer circumferential edge of theside face 34 is connected to the inner circumferential edge of thetop face 32. An inclination angle θ of theside face 34 with respect to thesurface 101 is set similarly to the inclination angle θ of theside face 20. The inclination angle θ of theside face 34 with respect to thesurface 101 may be the same as or different from the inclination angles θ of theside face 20, theside face 28, and theside face 30. The inclination angle θ of theside face 34 with respect to thesurface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. On that occasion, the distance from the load point PL and ease of forming of a material may also be taken into consideration. - A
ridge line 321 formed as the boundary between thetop face 32 and theside face 34 has a circular shape in a planar view. Theridge line 321 has a larger diameter than theridge line 262. As illustrated inFIG. 1 , theridge line 321 intersects the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 321 perpendicularly intersects all of the virtual straight lines extending radially from the load point PL. - The side face 36 is farther from the load point PL than the
top face 32 is. The side face 36 has a circular ring shape in a planar view. The inner circumferential edge of theside face 36 is farther from thesurface 101 than the outer circumferential edge of theside face 36 is. The inner circumferential edge of theside face 36 is connected to the outer circumferential edge of thetop face 32. The outer circumferential edge of theside face 36 is connected to thesurface 101. An inclination angle θ of theside face 36 with respect to thesurface 101 is set similarly to the inclination angle θ of theside face 20. The inclination angle θ of theside face 36 with respect to thesurface 101 may be the same as or different from the inclination angles θ of theside face 20, theside face 28, theside face 30, and theside face 34. The inclination angle θ of theside face 36 with respect to thesurface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. On that occasion, the distance from the load point PL and ease of forming of a material may also be taken into consideration. - A
ridge line 322 formed as the boundary between thetop face 32 and theside face 36 has a circular shape in a planar view. Theridge line 322 has a larger diameter than theridge line 321. As illustrated inFIG. 1 , theridge line 322 intersects the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 322 perpendicularly intersects all of the virtual straight lines extending radially from the load point PL. - The distance between the
ridge line 322 and theridge line 321, i.e., the width of thetop face 32, is 1 to 50 mm, for example. The width of thetop face 32 may be the same as or different from the width of thetop face 26. - The four
third protrusions 163 each protrude from thesurface 101. The fourthird protrusions 163 each have a substantially triangular shape in a planar view. The fourthird protrusions 163 are located at the four corners of the reinforcedsection 12. The fourthird protrusions 163 are located on a circle whose center is the load point PL. Thepanel 10 has, at a position where thethird protrusion 163 is formed, a recess opening toward the rear surface side. The recess has a shape corresponding to thethird protrusion 163. The fourthird protrusions 163 each include atop face 38, aside face 40, and aside face 42. - The
top face 38 has a substantially trapezoidal shape in a planar view. Thetop face 32 is away from thesurface 101 in the thickness direction of thepanel 10. Thetop face 38 is parallel to thesurface 101. The protrusion height of thethird protrusion 163, i.e., the distance between thetop face 38 and thesurface 101 in the thickness direction of thepanel 10, is 0.5 to 50 mm, for example. The protrusion height of thethird protrusion 163 may be the same as or different from the protrusion heights of thefirst protrusion 161, the first ring-shapedprotrusion 22, and the second ring-shapedprotrusion 24. The protrusion height of thethird protrusion 163 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. - The side face 40 is located closer to the load point PL than the
top face 38 is. The side face 40 has a substantially trapezoidal shape in a planar view. The lower end edge of theside face 40 is connected to thesurface 101. The upper end edge of theside face 40 is connected to thetop face 38. An inclination angle θ of theside face 40 with respect to thesurface 101 is set similarly to the inclination angles θ of theside face 20, theside face 28, theside face 30, theside face 34, and theside face 36. The inclination angle θ of theside face 40 with respect to thesurface 101 may be the same as or different from the inclination angles θ of theside face 20, theside face 28, theside face 30, theside face 34, and theside face 36. The inclination angle θ of theside face 40 with respect to thesurface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. On that occasion, the distance from the load point PL and ease of forming of a material may also be taken into consideration. - The side face 42 is farther from the load point PL than the
top face 38 is. The side face 42 has a substantially trapezoidal shape in a planar view. The lower end edge of theside face 42 is connected to thesurface 101. The upper end edge of theside face 42 is connected to thetop face 38. An inclination angle θ of theside face 42 with respect to thesurface 101 is set similarly to the inclination angles θ of theside face 20, theside face 28, theside face 30, theside face 34, theside face 36, and theside face 40. The inclination angle θ of theside face 42 with respect to thesurface 101 may be the same as or different from the inclination angles θ of theside face 20, theside face 28, theside face 30, theside face 34, theside face 36, and theside face 40. The inclination angle θ of theside face 42 with respect to thesurface 101 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as will be described later. On that occasion, the distance from the load point PL and ease of forming of a material may also be taken into consideration. - At each of the
third protrusions 163, aridge line 381 formed as the boundary between thetop face 38 and theside face 40 intersects one of the four virtual straight lines L11, L12, L13, and L14 perpendicularly. In addition, at each of thethird protrusions 163, aridge line 382 formed as the boundary between thetop face 38 and theside face 42 intersects one of the four virtual straight lines L11, L12, L13, and L14 perpendicularly. - The distance between the
ridge line 382 and theridge line 381, i.e., the width of thetop face 38, is 1 to 50 mm, for example. The width of thetop face 38 may be the same as or different from the widths of thetop face 26 and thetop face 32. - In the
panel 10 according to the present embodiment, modes of thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 are set in consideration of surface rigidity against an assumed load applied to the load point PL. - For example, the heights of the
first protrusion 161, thesecond protrusions 162, and thethird protrusions 163 may be made larger for larger assumed loads. Moreover, the inclination angles θ of the side faces 20, 28, 30, 34, 36, 40, and 42 forming thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 can be made larger for larger assumed loads. The heights of thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 and the inclination angles θ of the side faces 20, 28, 30, 34, 36, 40, and 42 are elements of the cross-sectional shapes of thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163. Such elements of the cross-sectional shapes may have an influence on the magnitude of the surface rigidity of each of thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163. - Larger heights of the
first protrusion 161, thesecond protrusions 162, and thethird protrusions 163 and larger inclination angles θ of the side faces 20, 28, 30, 34, 36, 40, and 42 result in difficulty in forming of a material. In particular, in the case where a sheet material made of a steel material is subjected to press forming, sheet thickness tends to be reduced, and cracking is likely to occur in the sheet material. In thepanel 10, the heights of thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 and the inclination angles θ of the side faces 20, 28, 30, 34, 36, 40, and 42 are set in accordance with the magnitude of the assumed load. Thus, thepanel 10 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - In addition, the widths of the top faces 18, 26, 32, and 38 and the intervals between the
first protrusion 161, thesecond protrusions 162, and thethird protrusions 163 may be made smaller for larger assumed loads. The widths of the top faces 18, 26, 32, and 38 and the intervals between thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 have an influence on the density of theprotrusions 16 of thepanel 10. The density of theprotrusions 16 may have an influence on the magnitude of the surface rigidity of each region of thepanel 10. - Smaller widths of the top faces 18, 26, 32, and 38 and smaller intervals between the
first protrusion 161, thesecond protrusions 162, and thethird protrusions 163 result in difficulty in forming of a material. In particular, in the case where a sheet material made of a steel material is subjected to press forming, sheet thickness tends to be reduced, and cracking is likely to occur in the sheet material. In thepanel 10, the widths of the top faces 18, 26, 32, and 38 and the intervals between thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 are set in accordance with the magnitude of the assumed load. Thus, thepanel 10 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusion 161, thesecond protrusions 162, and thethird protrusions 163 may all be the same, or some or all may be different. The inclination angles θ of the side faces 20, 28, 30, 34, 36, 40, and 42 forming thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 may all be the same, or some or all may be different. Also the widths of the top faces 18, 26, 32, and 38 may all be the same, or some or all may be different. Also the intervals between thefirst protrusion 161, thesecond protrusions 162, and thethird protrusions 163 may all be the same, or some or all may be different. - The presence or absence of the
third protrusions 163 and the number of thesecond protrusions 162 may also be set in accordance with the magnitude of the assumed load. The presence or absence of thethird protrusions 163 and the number of thesecond protrusions 162 have an influence on a formation range of theprotrusions 16. The formation range of theprotrusions 16 may have an influence on the magnitude of the surface rigidity of theentire panel 10. Changing the formation range of theprotrusions 16 also allows thepanel 10 to have appropriate surface rigidity in accordance with the assumed load. - In the above-described
panel 10 according to the present embodiment, theridge lines panel 10. In particular, since the plurality ofprotrusions 16 forming theridge lines panel 10 may receive. - In the
panel 10, the first ring-shapedprotrusion 22, the second ring-shapedprotrusion 24, and thethird protrusion 163 have the top faces 26, 32, and 38, respectively. This increases the number of ridge lines that intersect the virtual straight lines extending radially from the load point PL. As a result, the moment of inertia of area is further increased, making it easy to provide appropriate surface rigidity against the load that thepanel 10 may receive. - In the
panel 10, theridge lines panel 10, out of the virtual straight lines extending radially from the load point PL. This increases the number of ridge lines that intersect the virtual straight lines L11, L12, L13, and L14 between the load point PL and the vertices V11, V12, V13, and V14. This results in a further increase in the moment of inertia of area of a cross section taken along each of the virtual straight lines L11, L12, L13, and L14. - The shapes of the
protrusions 16 in thepanel 10 according to the present embodiment, specifically, the shapes of theridge lines - A
panel 50 according to a second embodiment will be described with reference toFIGS. 3 and 4 .FIG. 3 is a plan view of thepanel 50.FIG. 4 is a IV-IV cross-sectional view ofFIG. 3 . Thepanel 50 according to the second embodiment differs from thepanel 10 of the first embodiment in a configuration of a plurality ofprotrusions 52. The configuration of theprotrusions 52 is mainly described below; description is given on differences from theprotrusions 16 of the first embodiment. - The
protrusions 52 include afirst protrusion 521 and a plurality (two in the present embodiment) ofsecond protrusions 522. As in thepanel 10 of the first embodiment, the number of thesecond protrusions 522 is set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL. - The
first protrusion 521 protrudes from asurface 501 of thepanel 50. Thefirst protrusion 521 is formed concentrically with the load point PL of thepanel 50 in a planar view. Thefirst protrusion 521 includes atop face 54. Thetop face 54 has a square shape in a planar view. As viewed from the thickness direction of thepanel 50, the center of thetop face 54 coincides with the load point PL. - The
first protrusion 521 includes aridge line 541. Theridge line 541 has a square shape in a planar view. As illustrated inFIG. 3 , theridge line 541 intersects the four virtual straight lines L11, L12, L13, and L14. Although not shown, theridge line 541 intersects all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 541 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The two
second protrusions 522 each protrude from thesurface 501. The twosecond protrusions 522 each have a square frame shape in a planar view. The twosecond protrusions 522 are formed concentrically with respect to the load point PL. Hereinafter, one of the twosecond protrusions 522 that is closer to the load point PL will be called a first ring-shapedprotrusion 56, and one of the twosecond protrusions 522 that is farther from the load point PL will be called a second ring-shapedprotrusion 58. - The first ring-shaped
protrusion 56 includes atop face 60. Thetop face 60 has a square frame shape in a planar view. The first ring-shapedprotrusion 56 includes aridge line 601 and aridge line 602. Theridge line 601 is located closer to the load point PL than theridge line 602 is. Theridge line 601 and theridge line 602 each have a square shape in a planar view. As illustrated inFIG. 3 , theridge line 601 and theridge line 602 intersect the four virtual straight lines L11, L12, L13, and L14. Although not shown, theridge line 601 and theridge line 602 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 601 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge line 602 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The second ring-shaped
protrusion 58 includes atop face 62. Thetop face 62 has a square frame shape in a planar view. The second ring-shapedprotrusion 58 includes aridge line 621 and aridge line 622. Theridge line 621 is located closer to the load point PL than theridge line 622 is. Theridge line 621 and theridge line 622 each have a square shape in a planar view. As illustrated inFIG. 3 , theridge line 621 and theridge line 622 intersect the four virtual straight lines L11, L12, L13, and L14. Although not shown, theridge line 621 and theridge line 622 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 621 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge line 622 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - In the
panel 50 according to the present embodiment, modes of thefirst protrusion 521 and thesecond protrusions 522 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of thefirst protrusion 521 and thesecond protrusions 522 and the inclination angles θ of the side faces forming thefirst protrusion 521 and thesecond protrusions 522 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 54, 60, and 62 and the intervals between thefirst protrusion 521 and thesecond protrusions 522 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 50 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusion 521 and thesecond protrusions 522 may all be the same, or some or all may be different. The inclination angles θ of the side faces forming thefirst protrusion 521 and thesecond protrusions 522 may all be the same, or some or all may be different. Also the widths of the top faces 54, 60, and 62 may all be the same, or some or all may be different. Also the intervals between thefirst protrusion 521 and thesecond protrusions 522 may all be the same, or some or all may be different. The number of thesecond protrusions 522 can also be set in accordance with the magnitude of the assumed load. - The
panel 50 according to the second embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 70 according to a third embodiment will be described with reference toFIGS. 5 and 6 .FIG. 5 is a plan view of thepanel 70.FIG. 6 is a VI-VI cross-sectional view ofFIG. 5 . Thepanel 70 according to the third embodiment differs from thepanel 10 of the first embodiment in a configuration of a plurality of protrusions 72. The configuration of the protrusions 72 is mainly described below; description is given on differences from theprotrusions 16 of the first embodiment. - The protrusions 72 include a
first protrusion 721, a plurality (two in the present embodiment) ofsecond protrusions 722, and a plurality (four in the present embodiment) ofthird protrusions 723. Note that the numbers of thesecond protrusions 722 and thethird protrusions 723 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as in thepanel 10 of the first embodiment. - The
first protrusion 721 protrudes from asurface 701 of thepanel 70. Thefirst protrusion 721 is formed concentrically with the load point PL of thepanel 70 in a planar view. Thefirst protrusion 721 includes atop face 74. Thetop face 74 has a square shape in a planar view. As viewed from the thickness direction of thepanel 70, the center of thetop face 74 coincides with the load point PL. - The
first protrusion 721 includes aridge line 741. Theridge line 741 has a square shape in a planar view. As illustrated inFIG. 5 , theridge line 741 intersects the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 741 intersects all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 741 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The two
second protrusions 722 each protrude from thesurface 701. The twosecond protrusions 722 each have a square frame shape in a planar view. The twosecond protrusions 722 are formed concentrically with respect to the load point PL. Hereinafter, one of the twosecond protrusions 722 that is closer to the load point PL will be called a first ring-shapedprotrusion 76, and one of the twosecond protrusions 722 that is farther from the load point PL will be called a second ring-shapedprotrusion 78. - The first ring-shaped
protrusion 76 includes atop face 80. Thetop face 80 has a square frame shape in a planar view. The first ring-shapedprotrusion 76 includes aridge line 801 and aridge line 802. Theridge line 801 is located closer to the load point PL than theridge line 802 is. Theridge line 801 and theridge line 802 each have a square shape in a planar view. As illustrated inFIG. 5 , theridge line 801 and theridge line 802 intersect the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 801 and theridge line 802 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 801 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge line 802 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - In the present embodiment, the second ring-shaped
protrusion 78 includes a plurality (four in the present embodiment) of top faces 82. Thetop face 82 has a trapezoidal shape in a planar view. The second ring-shapedprotrusion 78 includes fourridge lines 821 and fourridge lines 822. The ridge lines 821 are located closer to the load point PL than theridge lines 822 are. As illustrated inFIG. 5 , theridge lines 821 and theridge lines 822 intersect the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge lines 821 and theridge lines 822 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge lines 821 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge lines 822 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The four
third protrusions 723 each protrude from thesurface 701. The fourthird protrusions 723 each have a substantially triangular shape in a planar view. - The four
third protrusions 723 are located around the load point PL serving as the center. The fourthird protrusions 723 are farther from the load point PL than the second ring-shapedprotrusion 78 is. - The
third protrusion 723 includes atop face 84. Thetop face 84 has a trapezoidal shape in a planar view. Thethird protrusion 723 includes aridge line 841 and aridge line 842. Theridge line 841 is located closer to the load point PL than theridge line 842 is. As illustrated inFIG. 5 , theridge line 841 and theridge line 842 perpendicularly intersect one of the four virtual straight lines L11, L12, L13, and L14. - In the
panel 70 according to the present embodiment, modes of thefirst protrusion 721, thesecond protrusions 722, and thethird protrusions 723 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of thefirst protrusion 721, thesecond protrusions 722, and thethird protrusions 723 and the inclination angles θ of the side faces forming thefirst protrusion 721, thesecond protrusions 722, and thethird protrusions 723 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 74, 80, 82, and 84 and the intervals between thefirst protrusion 721, thesecond protrusions 722, and thethird protrusions 723 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 70 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusion 721, thesecond protrusions 722, and thethird protrusions 723 may all be the same, or some or all may be different. The inclination angles θ of the side faces forming thefirst protrusion 721, thesecond protrusions 722, and thethird protrusions 723 may all be the same, or some or all may be different. Also the widths of the top faces 74, 80, 82, and 84 may all be the same, or some or all may be different. Also the intervals between thefirst protrusion 721, thesecond protrusions 722, and thethird protrusions 723 may all be the same, or some or all may be different. The numbers of thesecond protrusions 722 and thethird protrusions 723 can also be set in accordance with the magnitude of the assumed load. - The
panel 70 according to the third embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 90 according to a fourth embodiment will be described with reference toFIGS. 7 and 8 .FIG. 7 is a plan view of thepanel 90.FIG. 8 is a VIII-VIII cross-sectional view ofFIG. 7 . Thepanel 90 according to the fourth embodiment differs from thepanel 10 of the first embodiment in a configuration of a plurality ofprotrusions 92. The configuration of theprotrusions 92 is mainly described below; description is given on differences from theprotrusions 16 of the first embodiment. - The
protrusions 92 include afirst protrusion 921, asecond protrusion 922, a plurality (four in the present embodiment) ofthird protrusions 923, and a plurality (four in the present embodiment) offourth protrusions 924. Note that the numbers of thesecond protrusions 922, thethird protrusions 923, and thefourth protrusions 924 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as in thepanel 10 of the first embodiment. - The
first protrusion 921 protrudes from asurface 901 of thepanel 90. Thefirst protrusion 921 is formed concentrically with the load point PL of thepanel 90 in a planar view. Thefirst protrusion 921 includes atop face 93. Thetop face 93 has a substantially square shape in a planar view. As viewed from the thickness direction of thepanel 90, the center of thetop face 93 coincides with the load point PL. - The
first protrusion 921 includes aridge line 931. Theridge line 931 has a substantially square shape in a planar view. As illustrated inFIG. 7 , theridge line 931 intersects the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 931 intersects all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 931 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The
second protrusion 922 protrudes from thesurface 901. Thesecond protrusion 922 is formed concentrically with respect to the load point PL. In other words, the center of thesecond protrusion 922 coincides with the load point PL in a planar view. Thesecond protrusion 922 includes four top faces 94. Thesecond protrusion 922 includes fourridge lines 941 and fourridge lines 942. The ridge lines 941 are located closer to the load point PL than theridge lines 942 are. The ridge lines 941 and theridge lines 942 each have a midpoint located closer to the load point PL than the straight line connecting both ends of theridge line 941 or theridge line 942 is. In other words, theridge lines 941 and theridge lines 942 each have an arc shape that is convex toward the load point PL in a planar view. As illustrated inFIG. 7 , theridge lines 941 and theridge lines 942 perpendicularly intersect the four virtual straight lines L11, L12, L13, and L14. - The four
third protrusions 923 protrude from thesurface 901. The fourthird protrusions 923 are located around the load point PL serving as the center. Thethird protrusions 923 are farther from the load point PL than thesecond protrusion 922 is. Thethird protrusion 923 includes atop face 96. Thethird protrusion 923 includes aridge line 961 and aridge line 962. Theridge line 961 is located closer to the load point PL than theridge line 962 is. Theridge line 961 and theridge line 962 each have a midpoint located closer to the load point PL than the straight lines connecting both ends of theridge line 961 and theridge line 962 are. In other words, theridge line 961 and theridge line 962 each have an arc shape that is convex toward the load point PL in a planar view. As illustrated inFIG. 7 , theridge line 961 and theridge line 962 perpendicularly intersect one of the four virtual straight lines L11, L12, L13, and L14. - The four
fourth protrusions 924 protrude from thesurface 901. The fourfourth protrusions 924 are located around the load point PL serving as the center. Thefourth protrusions 924 are farther from the load point PL than thethird protrusions 923 are. Thefourth protrusion 924 includes atop face 98. Thefourth protrusion 924 includes aridge line 981 and aridge line 982. Theridge line 981 is located closer to the load point PL than theridge line 982 is. Theridge line 981 and theridge line 982 each have a midpoint located closer to the load point PL than the straight lines connecting both ends of theridge line 981 and theridge line 982 are. In other words, theridge line 981 and theridge line 982 each have an arc shape that is convex toward the load point PL in a planar view. As illustrated inFIG. 7 , theridge line 981 and theridge line 982 perpendicularly intersect one of the four virtual straight lines L11, L12, L13, and L14. - In the
panel 90 according to the present embodiment, modes of thefirst protrusion 921, thesecond protrusion 922, thethird protrusions 923, and thefourth protrusions 924 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of thefirst protrusion 921, thesecond protrusion 922, thethird protrusions 923, and thefourth protrusions 924 and the inclination angles θ of the side faces forming thefirst protrusion 921, thesecond protrusion 922, thethird protrusions 923, and thefourth protrusions 924 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 93, 94, 96, and 98 and the intervals between thefirst protrusion 921, thesecond protrusion 922, thethird protrusions 923, and thefourth protrusions 924 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 90 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusion 921, thesecond protrusion 922, thethird protrusions 923, and thefourth protrusions 924 may all be the same, or some or all may be different. The inclination angles θ of the side faces forming thefirst protrusion 921, thesecond protrusion 922, thethird protrusions 923, and thefourth protrusions 924 may all be the same, or some or all may be different. Also the widths of the top faces 93, 94, 96, and 98 may all be the same, or some or all may be different. Also the intervals between thefirst protrusion 921, thesecond protrusion 922, thethird protrusions 923, and thefourth protrusions 924 may all be the same, or some or all may be different. The numbers of thesecond protrusions 922, thethird protrusions 923, and thefourth protrusions 924 can also be set in accordance with the magnitude of the assumed load. - The
panel 90 according to the fourth embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 100 according to a fifth embodiment will be described with reference toFIGS. 9 and 10 .FIG. 9 is a plan view of thepanel 100.FIG. 10 is a X-X cross-sectional view ofFIG. 9 . Thepanel 100 according to the fifth embodiment differs from thepanel 10 of the first embodiment in a configuration of a plurality ofprotrusions 102. The configuration of theprotrusions 102 is mainly described below; description is given on differences from theprotrusions 16 of the first embodiment. - The
panel 100 according to the present embodiment includes, as theprotrusions 102, twoprotrusions 1021. The number of theprotrusions 1021 may be one. - Each
protrusion 1021 protrudes from asurface 1001. Eachprotrusion 1021 has a spiral shape in a planar view. Eachprotrusion 1021 includes atop face 104. Eachprotrusion 1021 includes aridge line 1041 and aridge line 1042. Theridge line 1041 and theridge line 1042 each have a spiral shape in a planar view. At a given position of theprotrusion 1021, theridge line 1041 is located closer to the load point PL than theridge line 1042 is. As illustrated inFIG. 9 , theridge line 1041 and theridge line 1042 intersect the four virtual straight lines L11, L12, L13, and L14 at a plurality of positions. - Although not shown, the
ridge line 1041 and theridge line 1042 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 1041 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge line 1042 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - In the
panel 100 according to the present embodiment, modes of theprotrusions 1021 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of theprotrusions 1021 and the inclination angles θ of the side faces forming theprotrusions 1021 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 104 and the intervals between theprotrusions 1021 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 100 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
protrusions 1021 may be the same throughout the entire range, or some or all may be different. The inclination angles θ of the side faces forming theprotrusions 1021 may be the same throughout the entire range, or some or all may be different. Also the widths of the top faces 104 may be the same throughout the entire range, or some or all may be different. Also the intervals between theprotrusions 1021 may be the same throughout the entire range, or some or all may be different. The number of theprotrusions 1021 can also be set in accordance with the magnitude of the assumed load. - The
panel 100 according to the fifth embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 110 according to a sixth embodiment will be described with reference toFIGS. 11 and 12 .FIG. 11 is a plan view of thepanel 110.FIG. 12 is a XII-XII cross-sectional view ofFIG. 11 . Thepanel 110 according to the sixth embodiment differs from thepanel 10 of the first embodiment in a configuration of a plurality ofprotrusions 112. The configuration of theprotrusions 112 is mainly described below; description is given on differences from theprotrusions 16 of the first embodiment. - The
protrusions 112 include a plurality (two in the present embodiment) offirst protrusions 1121 and a plurality (six in the present embodiment) ofsecond protrusions 1122. Note that the numbers of thefirst protrusions 1121 and thesecond protrusions 1122 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as in thepanel 10 of the first embodiment. - The
first protrusions 1121 protrude from asurface 1101. Thefirst protrusions 1121 each have a spiral shape surrounding the load point PL serving as a base point in a planar view. Thefirst protrusion 1121 includes atop face 114 and atop face 116. Thefirst protrusion 1121 includes aridge line 1141, aridge line 1142, aridge line 1161, and aridge line 1162. - The
ridge line 1141 and theridge line 1142 each have a spiral shape in a planar view. As illustrated inFIG. 11 , theridge line 1141 and theridge line 1142 have portions perpendicularly intersecting the four virtual straight lines L11, L12, L13, and L14. Although not shown, theridge line 1141 and theridge line 1142 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 1141 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge line 1142 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The
ridge line 1161 and theridge line 1162 are parallel to each other in a planar view. Theridge line 1161 and theridge line 1162 of one of the twofirst protrusions 1121 perpendicularly intersect the virtual straight line L11. Theridge line 1161 and theridge line 1162 of the other of the twofirst protrusions 1121 perpendicularly intersect the virtual straight line L13. - The six
second protrusions 1122 protrude from thesurface 1101. Thesecond protrusions 1122 are farther from the load point PL than thefirst protrusions 1121 are. Thesecond protrusion 1122 includes atop face 118. Thesecond protrusion 1122 includes aridge line 1181 and aridge line 1182. Theridge line 1181 is located closer to the load point PL than theridge line 1182 is. - One of the six
second protrusions 1122 is located at a position intersecting the virtual straight line L11. In thissecond protrusion 1122, as illustrated inFIG. 11 , theridge line 1181 and theridge line 1182 perpendicularly intersect the virtual straight line L11. Two of the sixsecond protrusions 1122 are located at positions intersecting the virtual straight line L12. In thesesecond protrusions 1122, as illustrated inFIG. 11 , theridge line 1181 and theridge line 1182 perpendicularly intersect the virtual straight line L12. - One of the six
second protrusions 1122 is located at a position intersecting the virtual straight line L13. In thissecond protrusion 1122, as illustrated inFIG. 11 , theridge line 1181 and theridge line 1182 perpendicularly intersect the virtual straight line L13. Two of the sixsecond protrusions 1122 are located at positions intersecting the virtual straight line L14. In thesesecond protrusions 1122, as illustrated inFIG. 11 , theridge line 1181 and theridge line 1182 perpendicularly intersect the virtual straight line L14. - <6-3. Modes of Plurality of Protrusions>
- In the
panel 110 according to the present embodiment, modes of thefirst protrusions 1121 and thesecond protrusions 1122 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of thefirst protrusions 1121 and thesecond protrusions 1122 and the inclination angles θ of the side faces forming thefirst protrusions 1121 and thesecond protrusions 1122 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 114, 116, and 118 and the intervals between thefirst protrusions 1121 and thesecond protrusions 1122 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 110 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusions 1121 and thesecond protrusions 1122 may all be the same, or some or all may be different. The inclination angles θ of the side faces forming thefirst protrusions 1121 and thesecond protrusions 1122 may all be the same, or some or all may be different. Also the widths of the top faces 114, 116, and 118 may all be the same, or some or all may be different. Also the intervals between thefirst protrusions 1121 and thesecond protrusions 1122 may all be the same, or some or all may be different. The numbers of thefirst protrusions 1121 and thesecond protrusions 1122 can also be set in accordance with the magnitude of the assumed load. - The
panel 110 according to the sixth embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 120 according to a seventh embodiment will be described with reference toFIGS. 13 and 14 .FIG. 13 is a plan view of thepanel 120.FIG. 14 is a XIV-XIV cross-sectional view ofFIG. 13 . Thepanel 120 according to the seventh embodiment differs from thepanel 10 of the first embodiment in a configuration of a plurality ofprotrusions 122. The configuration of theprotrusions 122 is mainly described below; description is given on differences from theprotrusions 16 of the first embodiment. - The
protrusions 122 include afirst protrusion 1221, a plurality (two in the present embodiment) ofsecond protrusions 1222, and a plurality (four in the present embodiment) ofthird protrusions 1223. Note that the numbers of thesecond protrusions 1222 and thethird protrusions 1223 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as in thepanel 10 of the first embodiment. - The
first protrusion 1221 protrudes from asurface 1201 of thepanel 120. Thefirst protrusion 1221 is formed concentrically with the load point PL of thepanel 120 in a planar view. Thefirst protrusion 1221 includes atop face 124. Thetop face 124 has a regular octagonal shape in a planar view. As viewed from the thickness direction of thepanel 120, the center of thetop face 124 coincides with the load point PL. - The
first protrusion 1221 includes aridge line 1241. Theridge line 1241 has a square shape in a planar view. As illustrated inFIG. 13 , theridge line 1241 intersects the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 1241 intersects all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 1241 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The two
second protrusions 1222 each protrude from thesurface 1201. The twosecond protrusions 1222 are formed concentrically with respect to the load point PL. Hereinafter, one of the twosecond protrusions 1222 that is closer to the load point PL will be called a first ring-shapedprotrusion 126, and one of the twosecond protrusions 1222 that is farther from the load point PL will be called a second ring-shapedprotrusion 128. - The first ring-shaped
protrusion 126 includes atop face 130. Thetop face 130 has a regular octagonal frame shape in a planar view. The first ring-shapedprotrusion 126 includes aridge line 1301 and aridge line 1302. Theridge line 1301 is located closer to the load point PL than theridge line 1302 is. Theridge line 1301 and theridge line 1302 each have a regular octagonal shape in a planar view. As illustrated inFIG. 13 , theridge line 1301 and theridge line 1302 intersect the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 1301 and theridge line 1302 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. - In other words, acute angles out of angles formed by the
ridge line 1301 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge line 1302 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The second ring-shaped
protrusion 128 includes atop face 132. Thetop face 132 has a regular octagonal frame shape in a planar view. The second ring-shapedprotrusion 128 includes aridge line 1321 and aridge line 1322. Theridge line 1321 is located closer to the load point PL than theridge line 1322 is. Theridge line 1321 and theridge line 1322 each have a regular octagonal shape in a planar view. As illustrated inFIG. 13 , theridge line 1321 and theridge line 1322 intersect the four virtual straight lines L11, L12, L13, and L14 perpendicularly. Although not shown, theridge line 1321 and theridge line 1322 intersect all of the virtual straight lines extending radially from the load point PL at angles within a range of 45 to 90 degrees. In other words, acute angles out of angles formed by theridge line 1321 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees, and acute angles out of angles formed by theridge line 1322 and the virtual straight lines extending radially from the load point PL are within a range of 45 to less than 90 degrees. - The
third protrusions 1223 protrude from thesurface 1201. Thethird protrusions 1223 each have a substantially trapezoidal shape in a planar view. Thethird protrusions 1223 are farther from the load point PL than the second ring-shapedprotrusion 128 is. Thethird protrusion 1223 includes atop face 134. Thetop face 134 has a trapezoidal shape in a planar view. The ring-shapedthird protrusion 1223 includes aridge line 1341 and aridge line 1342. Theridge line 1341 is located closer to the load point PL than theridge line 1342 is. As illustrated inFIG. 13 , theridge line 1341 and theridge line 1342 perpendicularly intersect one of the four virtual straight lines L11, L12, L13, and L14. - In the
panel 120 according to the present embodiment, modes of thefirst protrusion 1221, thesecond protrusions 1222, and thethird protrusions 1223 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of thefirst protrusion 1221, thesecond protrusions 1222, and thethird protrusions 1223 and the inclination angles θ of the side faces forming thefirst protrusion 1221, thesecond protrusions 1222, and thethird protrusions 1223 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 124, 130, 132, and 134 and the intervals between thefirst protrusion 1221, thesecond protrusions 1222, and thethird protrusions 1223 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 120 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusion 1221, thesecond protrusions 1222, and thethird protrusions 1223 may all be the same, or some or all may be different. The inclination angles θ of the side faces forming thefirst protrusion 1221, thesecond protrusions 1222, and thethird protrusions 1223 may all be the same, or some or all may be different. Also the widths of the top faces 124, 130, 132, and 134 may all be the same, or some or all may be different. Also the intervals between thefirst protrusion 1221, thesecond protrusions 1222, and thethird protrusions 1223 may all be the same, or some or all may be different. The numbers of thesecond protrusions 1222 and thethird protrusions 1223 can also be set in accordance with the magnitude of the assumed load. - The
panel 90 according to the seventh embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 140 according to an eighth embodiment will be described with reference toFIGS. 15 and 16 .FIG. 15 is a plan view of thepanel 140.FIG. 16 is a XVI-XVI cross-sectional view ofFIG. 15 . Thepanel 140 according to the eighth embodiment differs from thepanel 10 of the first embodiment in a configuration of a plurality ofprotrusions 142. The configuration of theprotrusions 142 is mainly described below; description is given on differences from theprotrusions 16 of the first embodiment. In the following description, in the clockwise direction, i.e., the right-handed direction, the starting point side is called one end in the circumferential direction, and the endpoint side is called the other end in the circumferential direction. - The
protrusions 142 include afirst protrusion 1421, a plurality (two in the present embodiment) ofsecond protrusions 1422, a plurality (two in the present embodiment) ofthird protrusions 1423, a plurality (two in the present embodiment) offourth protrusions 1424, a plurality (two in the present embodiment) offifth protrusions 1425, a plurality (four in the present embodiment) ofsixth protrusions 1426, and a plurality (four in the present embodiment) ofseventh protrusions 1427. Note that the numbers of thefirst protrusion 1421 to theseventh protrusions 1427 are set appropriately in consideration of at least surface rigidity against an assumed load applied to the load point PL, as in thepanel 10 of the first embodiment. - The
first protrusion 1421 is located on the load point PL. Thefirst protrusion 1421 includes atop face 143. Thefirst protrusion 1421 includes aridge line 1431. Thetop face 143 and theridge line 1431 each have a circular shape in a planar view. As viewed from the thickness direction of thepanel 140, the center of thetop face 143 and the center of theridge line 1431 coincide with the load point PL. - The two
second protrusions 1422 are located on a first circle whose center is the load point PL. Thesecond protrusion 1422 includes atop face 144. Thesecond protrusion 1422 includes aridge line 1441 and aridge line 1442. Theridge line 1441 is located closer to the load point PL than theridge line 1442 is. Theridge line 1441 and theridge line 1442 each have a midpoint located farther from the load point PL than the straight lines connecting both ends of theridge line 1441 and theridge line 1442 are. In other words, theridge line 1441 and theridge line 1442 each have an arc shape that is convex toward a direction going away from the load point PL in a planar view. As illustrated inFIG. 15 , theridge line 1441 and theridge line 1442 perpendicularly intersect two of the four virtual straight lines L11, L12, L13, and L14. - One of the two
second protrusions 1422 is called thesecond protrusion 1422A, and the other is called thesecond protrusion 1422B. One end part in the circumferential direction of thesecond protrusion 1422A perpendicularly intersects the virtual straight line L11. The other end part in the circumferential direction of thesecond protrusion 1422A perpendicularly intersects the virtual straight line L12. - One end part in the circumferential direction of the
second protrusion 1422B perpendicularly intersects the virtual straight line L13. The other end part in the circumferential direction of thesecond protrusion 1422B perpendicularly intersects the virtual straight line L14. - The two
third protrusions 1423 are located on a second circle whose center is the load point PL. The second circle has a larger diameter than the first circle. Thethird protrusion 1423 includes atop face 146. Thethird protrusion 1423 includes aridge line 1461 and aridge line 1462. Theridge line 1461 is located closer to the load point PL than theridge line 1462 is. Theridge line 1461 and theridge line 1462 each have a midpoint located farther from the load point PL than the straight lines connecting both ends of theridge line 1461 and theridge line 1462 are. In other words, theridge line 1461 and theridge line 1462 each have an arc shape that is convex toward a direction going away from the load point PL in a planar view. As illustrated inFIG. 15 , theridge line 1461 and theridge line 1462 perpendicularly intersect two of the four virtual straight lines L11, L12, L13, and L14. - One of the two
third protrusions 1423 is called thethird protrusion 1423A, and the other is called thethird protrusion 1423B. One end part in the circumferential direction of thethird protrusion 1423A perpendicularly intersects the virtual straight line L14. The other end part in the circumferential direction of thethird protrusion 1423A perpendicularly intersects the virtual straight line L11. One end part in the circumferential direction of thethird protrusion 1423B perpendicularly intersects the virtual straight line L12. The other end part in the circumferential direction of thethird protrusion 1423B perpendicularly intersects the virtual straight line L13. - As viewed from the direction along which the virtual straight line L14 extends, the one end part in the circumferential direction of the
third protrusion 1423A overlaps with the other end part in the circumferential direction of thesecond protrusion 1422B. As viewed from the direction along which the virtual straight line L11 extends, the other end part in the circumferential direction of thethird protrusion 1423A overlaps with the one end part in the circumferential direction of thesecond protrusion 1422A. As viewed from the direction along which the virtual straight line L12 extends, the one end part in the circumferential direction of thethird protrusion 1423B overlaps with the other end part in the circumferential direction of thesecond protrusion 1422A. As viewed from the direction along which the virtual straight line L13 extends, the other end part in the circumferential direction of thethird protrusion 1423B overlaps with the one end part in the circumferential direction of thesecond protrusion 1422B. - The two
fourth protrusions 1424 are located on a third circle whose center is the load point PL. The third circle has a larger diameter than the second circle. Thefourth protrusion 1424 includes atop face 148. Thefourth protrusion 1424 includes aridge line 1481 and aridge line 1482. Theridge line 1481 is located closer to the load point PL than theridge line 1482 is. Theridge line 1481 and theridge line 1482 each have a midpoint located farther from the load point PL than the straight lines connecting both ends of theridge line 1481 and theridge line 1482 are. In other words, theridge line 1481 and theridge line 1482 each have an arc shape that is convex toward a direction going away from the load point PL in a planar view. As illustrated inFIG. 15 , theridge line 1481 and theridge line 1482 perpendicularly intersect two of the four virtual straight lines L11, L12, L13, and L14. - One of the two
fourth protrusions 1424 is called thefourth protrusion 1424A, and the other is called thefourth protrusion 1424B. One end part in the circumferential direction of thefourth protrusion 1424A perpendicularly intersects the virtual straight line L11. The other end part in the circumferential direction of thesecond protrusion 1422A perpendicularly intersects the virtual straight line L12. One end part in the circumferential direction of thefourth protrusion 1424B perpendicularly intersects the virtual straight line L13. The other end part in the circumferential direction of thefourth protrusion 1424B perpendicularly intersects the virtual straight line L14. - As viewed from the direction along which the virtual straight line L11 extends, the one end part in the circumferential direction of the
fourth protrusion 1424A overlaps with the other end part in the circumferential direction of thethird protrusion 1423A and the one end part in the circumferential direction of thesecond protrusion 1422A. As viewed from the direction along which the virtual straight line L12 extends, the other end part in the circumferential direction of thefourth protrusion 1424A overlaps with the one end part in the circumferential direction of thethird protrusion 1423B and the other end part in the circumferential direction of thesecond protrusion 1422A. As viewed from the direction along which the virtual straight line L13 extends, the one end part in the circumferential direction of thefourth protrusion 1424B overlaps with the other end part in the circumferential direction of thethird protrusion 1423B and the one end part in the circumferential direction of thesecond protrusion 1422B. As viewed from the direction along which the virtual straight line L14 extends, the other end part in the circumferential direction of thefourth protrusion 1424B overlaps with the other end part in the circumferential direction of thethird protrusion 1423A and the one end part in the circumferential direction of thethird protrusion 1423B. - The two
fifth protrusions 1425 are located on a fourth circle whose center is the load point PL. The fourth circle has a larger diameter than the third circle. Thefifth protrusion 1425 includes atop face 150. Thefifth protrusion 1425 includes aridge line 1501 and aridge line 1502. Theridge line 1501 is located closer to the load point PL than theridge line 1502 is. Theridge line 1501 and theridge line 1502 each have a midpoint located farther from the load point PL than the straight lines connecting both ends of theridge line 1501 and theridge line 1502 are. In other words, theridge line 1501 and theridge line 1502 each have an arc shape that is convex toward a direction going away from the load point PL in a planar view. As illustrated inFIG. 15 , theridge line 1501 and theridge line 1502 perpendicularly intersect two of the four virtual straight lines L11, L12, L13, and L14. - One of the two
fifth protrusions 1425 is called thefifth protrusion 1425A, and the other is called thefifth protrusion 1425B. One end part in the circumferential direction of thefifth protrusion 1425A perpendicularly intersects the virtual straight line L14. The other end part in the circumferential direction of thefifth protrusion 1425A perpendicularly intersects the virtual straight line L11. One end part in the circumferential direction of thefifth protrusion 1425B perpendicularly intersects the virtual straight line L12. The other end part in the circumferential direction of thefifth protrusion 1425B perpendicularly intersects the virtual straight line L13. - As viewed from the direction along which the virtual straight line L14 extends, the one end part in the circumferential direction of the
fifth protrusion 1425A overlaps with the other end part in the circumferential direction of thefourth protrusion 1424B, the one end part in the circumferential direction of thethird protrusion 1423A, and the other end part in the circumferential direction of thethird protrusion 1423B. As viewed from the direction along which the virtual straight line L11 extends, the other end part in the circumferential direction of thefifth protrusion 1425A overlaps with the one end part in the circumferential direction of thefourth protrusion 1424A, the other end part in the circumferential direction of thethird protrusion 1423A, and the one end part in the circumferential direction of thesecond protrusion 1422A. As viewed from the direction along which the virtual straight line L12 extends, the one end part in the circumferential direction of thefifth protrusion 1425B overlaps with the other end part in the circumferential direction of thefourth protrusion 1424A, the one end part in the circumferential direction of thethird protrusion 1423B, and the other end part in the circumferential direction of thesecond protrusion 1422A. As viewed from the direction along which the virtual straight line L13 extends, the other end part in the circumferential direction of thefifth protrusion 1425B overlaps with the one end part in the circumferential direction of thefourth protrusion 1424B, the other end part in the circumferential direction of thethird protrusion 1423B, and the one end part in the circumferential direction of thesecond protrusion 1422B. - <8-6. Sixth Protrusion>
- The four
sixth protrusions 1426 are located on a fifth circle whose center is the load point PL. The fifth circle has a larger diameter than the fourth circle. Thesixth protrusion 1426 includes atop face 152. Thesixth protrusion 1426 includes aridge line 1521 and aridge line 1522. Theridge line 1521 is located closer to the load point PL than theridge line 1522 is. Theridge line 1521 and theridge line 1522 each have a midpoint located farther from the load point PL than the straight lines connecting both ends of theridge line 1521 and theridge line 1522 are. In other words, theridge line 1521 and theridge line 1522 each have an arc shape that is convex toward a direction going away from the load point PL in a planar view. As illustrated inFIG. 15 , theridge line 1521 and theridge line 1522 perpendicularly intersect one of the four virtual straight lines L11, L12, L13, and L14. - One end part in the circumferential direction of the
sixth protrusion 1426A out of the foursixth protrusions 1426 perpendicularly intersects the virtual straight line L11. The other end in the circumferential direction of thesixth protrusion 1426A is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. As viewed from the direction along which the virtual straight line L11 extends, the one end part in the circumferential direction of thesixth protrusion 1426A overlaps with the other end part in the circumferential direction of thefifth protrusion 1425A, the one end part in the circumferential direction of thefourth protrusion 1424A, the other end part in the circumferential direction of thethird protrusion 1423A, and the one end part in the circumferential direction of thesecond protrusion 1422A. - One end in the circumferential direction of the
sixth protrusion 1426B out of the foursixth protrusions 1426 is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. The other end part in the circumferential direction of thesixth protrusion 1426B perpendicularly intersects the virtual straight line L12. As viewed from the direction along which the virtual straight line L12 extends, the other end part in the circumferential direction of thesixth protrusion 1426B overlaps with the one end part in the circumferential direction of thefifth protrusion 1425B, the other end part in the circumferential direction of thefourth protrusion 1424A, the one end part in the circumferential direction of thethird protrusion 1423B, and the other end part in the circumferential direction of thesecond protrusion 1422A. - One end part in the circumferential direction of the
sixth protrusion 1426C out of the foursixth protrusions 1426 perpendicularly intersects the virtual straight line L13. The other end in the circumferential direction of thesixth protrusion 1426C is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. As viewed from the direction along which the virtual straight line L13 extends, the one end part in the circumferential direction of thesixth protrusion 1426C overlaps with the other end part in the circumferential direction of thefifth protrusion 1425B, the one end part in the circumferential direction of thefourth protrusion 1424B, the other end part in the circumferential direction of thethird protrusion 1423B, and the one end part in the circumferential direction of thesecond protrusion 1422B. - One end in the circumferential direction of the
sixth protrusion 1426D out of the foursixth protrusions 1426 is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. The other end part in the circumferential direction of thesixth protrusion 1426D perpendicularly intersects the virtual straight line L14. As viewed from the direction along which the virtual straight line L14 extends, the other end part in the circumferential direction of thesixth protrusion 1426D overlaps with the one end part in the circumferential direction of thefifth protrusion 1425A, the other end part in the circumferential direction of thefourth protrusion 1424B, the one end part in the circumferential direction of thethird protrusion 1423A, and the other end part in the circumferential direction of thesecond protrusion 1422B. - The four
seventh protrusions 1427 are located on a sixth circle whose center is the load point PL. The sixth circle has a larger diameter than the fifth circle. Theseventh protrusion 1427 includes atop face 154. Theseventh protrusion 1427 includes aridge line 1541 and aridge line 1542. Theridge line 1541 is located closer to the load point PL than theridge line 1542 is. Theridge line 1541 and theridge line 1542 each have a midpoint located farther from the load point PL than the straight lines connecting both ends of theridge line 1541 and theridge line 1542 are. In other words, theridge line 1541 and theridge line 1542 each have an arc shape that is convex toward a direction going away from the load point PL in a planar view. As illustrated inFIG. 15 , theridge line 1541 and theridge line 1542 perpendicularly intersect one of the four virtual straight lines L11, L12, L13, and L14. - One end in the circumferential direction of the
seventh protrusion 1427A out of the fourseventh protrusions 1427 is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. The other end part in the circumferential direction of theseventh protrusion 1427A perpendicularly intersects the virtual straight line L11. As viewed from the direction along which the virtual straight line L11 extends, the other end part in the circumferential direction of theseventh protrusion 1427 overlaps with the one end part in the circumferential direction of thesixth protrusion 1426A, the other end part in the circumferential direction of thefifth protrusion 1425A, the one end part in the circumferential direction of thefourth protrusion 1424A, the other end part in the circumferential direction of thethird protrusion 1423A, and the one end part in the circumferential direction of thesecond protrusion 1422A. - One end part in the circumferential direction of the
seventh protrusion 1427B out of the fourseventh protrusions 1427 perpendicularly intersects the virtual straight line L12. The other end in the circumferential direction of theseventh protrusion 1427A is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. As viewed from the direction along which the virtual straight line L12 extends, the one end part in the circumferential direction of theseventh protrusion 1427B overlaps with the other end part in the circumferential direction of thesixth protrusion 1426B, the one end part in the circumferential direction of thefifth protrusion 1425B, the other end part in the circumferential direction of thefourth protrusion 1424A, the one end part in the circumferential direction of thethird protrusion 1423B, and the other end part in the circumferential direction of thesecond protrusion 1422A. - One end in the circumferential direction of the
seventh protrusion 1427C out of the fourseventh protrusions 1427 is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. The other end part in the circumferential direction of theseventh protrusion 1427C perpendicularly intersects the virtual straight line L13. As viewed from the direction along which the virtual straight line L13 extends, the other end part in the circumferential direction of theseventh protrusion 1427C overlaps with the one end part in the circumferential direction of thesixth protrusion 1426C, the other end part in the circumferential direction of thefifth protrusion 1425B, the one end part in the circumferential direction of thefourth protrusion 1424B, the other end part in the circumferential direction of thethird protrusion 1423B, and the one end part in the circumferential direction of thesecond protrusion 1422B. - One end part in the circumferential direction of the
seventh protrusion 1427D out of the fourseventh protrusions 1427 perpendicularly intersects the virtual straight line L14. The other end in the circumferential direction of theseventh protrusion 1427D is located at the boundary between the reinforcedsection 12 and theperipheral edge 14. As viewed from the direction along which the virtual straight line L14 extends, the one end part in the circumferential direction of theseventh protrusion 1427D overlaps with the other end part in the circumferential direction of thesixth protrusion 1426D, the one end part in the circumferential direction of thefifth protrusion 1425A, the other end part in the circumferential direction of thefourth protrusion 1424B, the one end part in the circumferential direction of thethird protrusion 1423A, and the other end part in the circumferential direction of thesecond protrusion 1422B. - In the
panel 140 according to the present embodiment, modes of thefirst protrusion 1421 to theseventh protrusions 1427 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of thefirst protrusion 1421 to theseventh protrusions 1427 and the inclination angles θ of the side faces forming thefirst protrusion 1421 to theseventh protrusions 1427 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 143, 144, 146, 148, 150, 152, and 154 and the intervals between thefirst protrusion 1421 to theseventh protrusions 1427 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 140 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusion 1421 to theseventh protrusions 1427 may all be the same, or some or all may be different. The inclination angles θ of the side faces forming thefirst protrusion 1421 to theseventh protrusions 1427 may all be the same, or some or all may be different. Also the widths of the top faces 143, 144, 146, 148, 150, 152, and 154 may all be the same, or some or all may be different. Also the intervals between thefirst protrusion 1421 to theseventh protrusions 1427 may all be the same, or some or all may be different. The numbers of thefirst protrusion 1421 to theseventh protrusions 1427 can also be set in accordance with the magnitude of the assumed load. - As viewed from the direction along which the virtual straight line L11 extends, in two protrusions adjacent to each other in the direction, the circumferential length of portions that overlap with each other is set appropriately, in accordance with surface rigidity against an assumed load applied to the load point PL. Here, as illustrated in
FIG. 15 , the circumferential length of the portions overlapping with each other may be the same for two adjacent protrusions close to the load point PL and two adjacent protrusions far away from the load point PL. In other words, in two protrusions adjacent to each other in the direction along which the virtual straight line L11 extends, edges of the end parts in the circumferential direction intersecting the virtual straight line L11 may extend in a direction parallel to the virtual straight line L11. - Alternatively, as illustrated in
FIG. 17 , the circumferential length of the portions overlapping with each other may be larger for two adjacent protrusions far away from the load point PL than for two adjacent protrusions close to the load point PL. In other words, in two protrusions adjacent to each other in the direction along which the virtual straight line L11 extends, edges of the end parts in the circumferential direction intersecting the virtual straight line L11 may extend in a direction passing through the load point PL and intersecting the virtual straight line L11. In this case, an angle φ formed by one edge and the other edge is set appropriately in accordance with surface rigidity against an assumed load applied to the load point PL. - Although not shown, also as viewed from the direction along which the virtual straight line L12 extends, in two protrusions adjacent to each other in the direction, the circumferential length of portions that overlap with each other can be configured as illustrated in
FIG. 17 . Also as viewed from the direction along which the virtual straight line L13 extends, in two protrusions adjacent to each other in the direction, the circumferential length of portions that overlap with each other can be configured as illustrated inFIG. 17 . Also as viewed from the direction along which the virtual straight line L14 extends, in two protrusions adjacent to each other in the direction, the circumferential length of portions that overlap with each other can be configured as illustrated inFIG. 17 . - The
panel 140 according to the eighth embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 160 according to a ninth embodiment will be described with reference toFIGS. 18 and 19 .FIG. 18 is a plan view of thepanel 160.FIG. 19 is a XVI-XVI cross-sectional view ofFIG. 18 . Thepanel 160 according to the ninth embodiment differs from thepanel 140 of the eighth embodiment in a configuration of a plurality ofsecond protrusions 162. The configuration of thesecond protrusions 162 is mainly described below; description is given on differences from theprotrusions 142 of the eighth embodiment. In the following description, in the clockwise direction, i.e., the right-handed direction, the starting point side is called one end in the circumferential direction, and the endpoint side is called the other end in the circumferential direction. - The
panel 160 is obtained by adding, to thepanel 140 of the eighth embodiment, a plurality (two in the present embodiment) ofeighth protrusions 1621, a plurality (two in the present embodiment) ofninth protrusions 1622, a plurality (two in the present embodiment) oftenth protrusions 1623, and a plurality (two in the present embodiment) ofeleventh protrusions 1624. - The
eighth protrusions 1621 protrude from a surface 1601. Theeighth protrusions 1621 each include atop face 164. Thetop face 164 has a circular shape in a planar view. Theeighth protrusions 1621 each include aridge line 1641. Theridge line 1641 has a circular shape in a planar view. Like thesecond protrusions 1422, theeighth protrusions 1621 are located on the first circle. Theeighth protrusions 1621 are located between the twosecond protrusions 1422 adjacent to each other in the circumferential direction. - The
ninth protrusions 1622 protrude from the surface 1601. Theninth protrusions 1622 each include atop face 166. Thetop face 166 has a circular shape in a planar view. Theninth protrusions 1622 each include aridge line 1661. Theridge line 1661 has a circular shape in a planar view. Like thethird protrusions 1423, theninth protrusions 1622 are located on the second circle. Theninth protrusions 1622 are located between the twothird protrusions 1423 adjacent to each other in the circumferential direction. - The
tenth protrusions 1623 protrude from the surface 1601. Thetenth protrusions 1623 each include atop face 168. Thetop face 168 has a circular shape in a planar view. Thetenth protrusions 1623 each include aridge line 1681. Theridge line 1681 has a circular shape in a planar view. Like thefourth protrusions 1424, thetenth protrusions 1623 are located on the third circle. Thetenth protrusions 1623 are located between the twofourth protrusions 1424 adjacent to each other in the circumferential direction. - The
eleventh protrusions 1624 protrude from the surface 1601. Theeleventh protrusions 1624 each include atop face 170. Thetop face 170 has a circular shape in a planar view. Theeleventh protrusions 1624 each include aridge line 1701. Theridge line 1701 has a circular shape in a planar view. Like thefifth protrusions 1425, theeleventh protrusions 1624 are located on the fourth circle. Theeleventh protrusions 1624 are located between the twofifth protrusions 1425 adjacent to each other in the circumferential direction. - In the
panel 160 according to the present embodiment, modes of thefirst protrusion 1421 to theeleventh protrusions 1624 are set in consideration of surface rigidity against an assumed load applied to the load point PL. That is, as in thepanel 10 according to the first embodiment, the heights of thefirst protrusion 1421 to theeleventh protrusions 1624 and the inclination angles θ of the side faces forming thefirst protrusion 1421 to theeleventh protrusions 1624 can be set in accordance with the magnitude of the assumed load. In addition, as in thepanel 10 according to the first embodiment, the widths of the top faces 143, 144, 146, 148, 150, 152, 154, 164, 166, 168, and 170 and the intervals between thefirst protrusion 1421 to theeleventh protrusions 1624 can be set in accordance with the magnitude of the assumed load. Thus, thepanel 160 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
first protrusion 1421 to theeleventh protrusions 1624 may all be the same, or some or all may be different. The inclination angles θ of the side faces forming thefirst protrusion 1421 to theeleventh protrusions 1624 may all be the same, or some or all may be different. Also the widths of the top faces 143, 144, 146, 148, 150, 152, 154, 164, 166, 168, and 170 may all be the same, or some or all may be different. Also the intervals between thefirst protrusion 1421 to theeleventh protrusions 1624 may all be the same, or some or all may be different. The numbers of thesecond protrusions 1422 to theeleventh protrusions 1624 can also be set in accordance with the magnitude of the assumed load. - The
panel 160 according to the ninth embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment. - A
panel 2000 according to a tenth embodiment will be described with reference toFIG. 20 .FIG. 20 is a plan view of thepanel 2000. Thepanel 2000 according to the tenth embodiment includes a plurality ofload points P L 1 andP L 2. Provided around each of the load pointsP L 1 andP L 2 are protrusions intersecting, at a plurality of positions, each of a plurality of virtual straight lines extending radially from the correspondingload points P L 1 andP L 2. Hereinafter, description will be given using as an example thepanel 2000 including, as the protrusions, theprotrusions 16 formed on thepanel 10 according to the first embodiment. - The
panel 2000 according to the present embodiment has a rectangular shape in a planar view. Thepanel 2000 has the load point PO at the center of a left-half region 2000L and theload point P L 2 at the center of a right-half region 2000R. The left-half region 2000L of thepanel 2000 is provided withprotrusions 16L formed around theload point P L 1. Theprotrusions 16L include afirst protrusion 161L,second protrusions 162L, andthird protrusions 163L. - The right-
half region 2000R of thepanel 2000 is provided withprotrusions 16R formed around theload point P L 2. Theprotrusions 16R include afirst protrusion 161R,second protrusions 162R, andthird protrusions 163R. At a boundary portion B between the left-half region 2000L and the right-half region 2000R,top faces third protrusions surfaces 101 on the left and right are continuous. - In the
panel 2000 illustrated inFIG. 20 , at the boundary portion B between thethird protrusions FIG. 21 , a spot where the side faces 40L and 40R or the side faces 42L and 42R are connected may be provided with a curved surface to make the side faces 40L and 40R or the side faces 42L and 42R continuous via the curved surface. This configuration alleviates local stress concentration at the boundary portion B between the left-half region 2000L and the right-half region 2000R in a state where a load is applied to each of the load pointsP L 1 andP L 2. - In the
panel 2000, modes of theprotrusions P L 1 andP L 2. That is, as in thepanel 10 according to the first embodiment, the heights of theprotrusions protrusions panel 10 according to the first embodiment, the widths of the top faces of theprotrusions protrusions panel 2000 provided with appropriate surface rigidity in accordance with the assumed load can be produced with high yield. - The heights of the
protrusions protrusions protrusions protrusions second protrusions third protrusions - The
panel 2000 according to the tenth embodiment described above provides an effect similar to that of thepanel 10 of the first embodiment even in the case where a load is applied to a plurality of positions of thepanel 2000 from the outside. In particular, according to thepanel 2000 of the present embodiment, surface rigidity can be improved appropriately against an assumed load applied to each of the load pointsP L 1 andP L 2. - The shapes of the
protrusions panel 2000 according to the present embodiment, specifically, the shapes of theprotrusions protrusions 16 in thepanel 10 of the first embodiment, the shapes of the protrusions in the panel of any of the second to ninth embodiments may be used. The shapes of the protrusions formed in the left-half region 2000L may be the same as or different from the shapes of the protrusions formed in the right-half region 2000R. - In addition, the
protrusions load points P L 1 andP L 2 have the same cross-sectional shapes, density, and formation range in thepanel 2000 according to the present embodiment, but the cross-sectional shapes, density, and formation range may be changed between theprotrusions P L 1 andP L 2. Hereinafter, in eleventh to twelfth embodiments, description will be given on modifications in which protrusions formed in left and right regions have different formation ranges and densities. - A
panel 2100 according to an eleventh embodiment will be described with reference toFIG. 22 .FIG. 22 is a plan view of thepanel 2100. In thepanel 2100 according to the eleventh embodiment, the ranges of left andright regions protrusions panel 2000 of the tenth embodiment. - The
panel 2100 according to the present embodiment is an example of a panel in which an assumed load applied to theload point P L 1 is larger than an assumed load applied to theload point P L 2. In thispanel 2100, the formation range of theprotrusions 16L formed around theload point P L 1 is made larger than the formation range of theprotrusions 16R formed around theload point P L 2 so that surface rigidity against a load applied to theload point P L 1 is relatively large. At a boundary portion B between the left-half region 2100L provided with theprotrusions 16L and the right-half region 2100R provided with theprotrusions 16R, end parts of thesecond protrusion 162R of theprotrusions 16R are formed so as to prevent interference between theprotrusions - In the
panel 2100 according to the eleventh embodiment, the formation ranges of theprotrusions P L 1 andP L 2, and the formation range of theprotrusions 16L formed around theload point P L 1 with a larger assumed load is made larger. In this manner, surface rigidity centered at theload point P L 1 can be improved relatively, and thus surface rigidity can be improved appropriately against an assumed load applied to each of the load pointsP L 1 andP L 2. - In the
panel 2100 illustrated inFIG. 22 , in forming theprotrusions panel 2100, the formation ranges of theprotrusions P L 1 andP L 2. In contrast, as illustrated inFIG. 23 , within the ranges of the left-half region 2100L including theload point P L 1 and the right-half region 2100R including theload point P L 2, the formation ranges of theprotrusions - The shapes of the
protrusions panel 2100 according to the present embodiment, specifically, the shapes of theprotrusions protrusions 16 in thepanel 10 of the first embodiment, the shapes of the protrusions in the panel of any of the second to ninth embodiments may be used. The shapes of the protrusions formed in the left-half region 2100L may be the same as or different from the shapes of the protrusions formed in the right-half region 2100R. - A
panel 2300 according to a twelfth embodiment will be described with reference toFIG. 24 .FIG. 24 is a plan view of thepanel 2300. In thepanel 2300 according to the twelfth embodiment, theprotrusions right regions panel 2000 of the twelfth embodiment. - The
panel 2300 according to the present embodiment is an example of a panel in which an assumed load applied to theload point P L 1 is larger than an assumed load applied to theload point P L 2. In thispanel 2100, the density of theprotrusions 16L formed around theload point P L 1 is made higher than the density of theprotrusions 16R formed around theload point P L 2 so that surface rigidity against a load applied to theload point P L 1 is relatively large. At a boundary portion B between the left-half region 2300L provided with theprotrusions 16L and the right-half region 2300R provided with theprotrusions 16R, the position of the boundary portion B is set such that the top faces 38L and 38R, side faces 40L and 40R, and side faces 42L and 42R of thethird protrusions surfaces 101 on the left and right are continuous. - In the
panel 2300 according to the twelfth embodiment, the densities of theprotrusions P L 1 andP L 2, and the density of theprotrusions 16L formed around theload point P L 1 with a larger assumed load is made higher. In this manner, surface rigidity centered at theload point P L 1 can be improved relatively, and thus surface rigidity can be improved appropriately against an assumed load applied to each of the load pointsP L 1 andP L 2. - The shapes of the
protrusions panel 2300 according to the present embodiment, specifically, the shapes of theprotrusions protrusions 16 in thepanel 10 of the first embodiment, the shapes of the protrusions in the panel of any of the second to ninth embodiments may be used. The shapes of the protrusions formed in the left-half region 2300L may be the same as or different from the shapes of the protrusions formed in the right-half region 2300R. In addition to the densities of theprotrusions protrusions - Surface rigidity was evaluated, by FEM analysis, for each of the
panels panel 180 illustrated inFIG. 25 (Comparative Example 1) and apanel 190 illustrated inFIG. 26 (Comparative Example 2). - For the FEM analysis, a commercially available general-use program code, LS-DYNA ver. 971 rev 6.1.1 was used. Calculation was performed by a static implicit method. A 285-mm-square square-shaped sheet material with a 15-mm flange was used as each panel. The flange was formed by perpendicularly bending an end edge part of the panel. The material of each panel was a steel material (Young's modulus: 206.5 GPa, Poisson's ratio: 0.3, density: 7.85 g/cm3). Sheet thickness was 0.6 mm. Displacement when a load (10N) was applied to the center of the panel with the four corners of the panel and the center of each side of the panel restrained was calculated. The range of load application had a square shape. The length of each side of the range of load application (square shape) was of four types, 20 mm, 50 mm, 100 mm, and 150 mm.
- In the panels according to Examples 1 to 9, the widths of the top faces of the protrusions were 2 mm, the inclination angles θ of the side faces of the protrusions with respect to the surface of the panel were 45 degrees, the interval between two protrusions adjacent to each other in a direction from the range of load application (load point) toward the outer side (the interval between the top face of one protrusion and the top face of the other protrusion) was 10 mm, and the depth of protrusions and recesses was 3 mm. For Example 1, the diameter of the top face of the protrusion located on the load point PL was set to 3 mm. For Examples 2, 3, and 4, the length of one side of the top face of the protrusion located on the load point PL was set to 6 mm. For Examples 8 and 9, the angle φ shown in
FIG. 17 was set to 30 degrees. - The
panel 180 according to Comparative Example 1 has a protrusion 182, as illustrated inFIG. 25 . Here,FIG. 25 is an explanatory diagram illustrating the shape of a top face of the protrusion 182. In practice, an inclined surface is formed at an edge portion of the protrusion 182. For easy understanding, the protrusion 182 is hatched inFIG. 25 . An inclination angle of the inclined surface with respect to asurface 1801 of thepanel 180 was 45 degrees. The protrusion height of the protrusion 182 from the surface 1801 (the depth of protrusions and recesses of the panel 180) was 3 mm. - In the protrusion 182, a dimension D1 was 24 mm. A dimension D2 was 40 mm. A dimension D3 was 8 mm. A dimension D4 was 8 mm. A dimension D5 was 8 mm. A dimension D6 was 24 mm. A dimension D7 was 20 mm. A dimension D8 was 24 mm. A dimension D9 was 3 mm. A dimension D10 was 3 mm. A dimension D11 was 15 mm. A dimension D12 was 24 mm. A dimension D13 was 3 mm. A dimension D14 was 8 mm. A dimension D15 was 24 mm. A dimension D16 was 40 mm.
- The
panel 190 according to Comparative Example 2 has aprotrusion 192, as illustrated inFIG. 26 . Here,FIG. 26 is an explanatory diagram illustrating the shape of a top face of theprotrusion 192. In practice, an inclined surface is formed at an edge portion of theprotrusion 192. For easy understanding, theprotrusion 192 is hatched inFIG. 26 . An inclination angle of the inclined surface with respect to asurface 1901 of thepanel 190 was 45 degrees. The protrusion height of theprotrusion 192 from the surface 1901 (the depth of protrusions and recesses of the panel 190) was 3 mm. - In the
protrusion 192, a dimension D1 was 24 mm. A dimension D2 was 40 mm. A dimension D3 was 8 mm. A dimension D4 was 3 mm. A dimension D5 was 11 mm. A dimension D6 was 24 mm. A dimension D7 was 18 mm. A dimension D8 was 40 mm. A dimension D9 was 48 mm. A dimension D10 was 3 mm. A dimension D11 was 18 mm. A dimension D12 was 12 mm. -
FIGS. 27 to 30 show the analysis results.FIG. 27 is a graph showing the results when the range of load application had a 20-mm-square square shape.FIG. 28 is a graph showing the results when the range of load application had a 50-mm-square square shape.FIG. 29 is a graph showing the results when the range of load application had a 100-mm-square square shape.FIG. 30 is a graph showing the results when the range of load application had a 150-mm-square square shape. - In
FIGS. 27 to 30 , the vertical axis indicates the rate of increase in surface rigidity relative to a flat plate. The rate of increase was determined in the following manner. First, displacement when a load was applied to the flat plate was calculated in the manner as described above. Then, the displacement when a load was applied to the flat plate was divided by displacement when a load was applied to the panel with a protrusion; thus, the rate of increase was determined. - As shown in
FIGS. 27 to 30 , Examples 1 to 9 exhibited improved surface rigidity as compared with Comparative Examples 1 and 2. Examples 1, 3, and 6 to 9 exhibited improved surface rigidity as compared with Examples 2, 4, and 5. A larger number of ridge lines that perpendicularly intersect the virtual straight lines extending radially from the load point PL resulted in more improved surface rigidity. Surface rigidity was improved when there existed a ridge line that perpendicularly intersects a straight line connecting the load point PL and a vertex of the panel. - For the panel according to Example 8, surface rigidity in the cases of different angles φ shown in
FIG. 17 was evaluated by FEM analysis. Specifically, the angles φ of 5 degrees, 10 degrees, 20 degrees, 30 degrees, and 40 degrees were assumed. For comparison, surface rigidity was evaluated by FEM analysis also for the panel according to Example 1 and the panel according to Comparative Example 1. Here, the panel according to Example 1 corresponds to the case of the angle φ being 90 degrees. Analysis conditions were the same as those forEvaluation 1. -
FIGS. 31 to 34 show the analysis results.FIG. 31 is a graph showing the results when the range of load application had a 20-mm-square square shape.FIG. 32 is a graph showing the results when the range of load application had a 50-mm-square square shape.FIG. 33 is a graph showing the results when the range of load application had a 100-mm-square square shape.FIG. 34 is a graph showing the results when the range of load application had a 150-mm-square square shape. - As shown in
FIGS. 31 to 34 , larger angles φ resulted in more improved surface rigidity. - The preferred embodiment(s) of the present invention has/have been described above with reference to the accompanying drawings, whilst the present invention is not limited to the above examples. A person skilled in the art may find various alterations and modifications within the scope of the appended claims, and it should be understood that they will naturally come under the technical scope of the present invention.
- For example, the panel need not have a peripheral edge for attaching the panel to another member, around a region where the protrusions are formed (the reinforced section in the above embodiments). The region where the protrusions are formed (the reinforced section in the above embodiments) may be formed on a flat surface, or may be formed on a curved surface. A portion where a ridge line is formed may be subjected to filleting.
- The above embodiments illustrate modes in which a plurality of protrusions are arranged at regular intervals in a predetermined cross section passing through the load point PL. In order for a load to be received uniformly, it is preferable to arrange a plurality of protrusions at regular intervals in a predetermined cross section passing through the load point PL as in these embodiments. However, the intervals between the protrusions may differ entirely or partially in the panel as long as characteristics required of the panel are allowed. For convenience in design, etc., there may be a portion where the protrusions are not provided. For example, the protrusions may be partially chipped as long as characteristics required of the panel are allowed.
-
- 10 panel
- 12 reinforced section
- 14 peripheral edge
- 16 protrusion
- 18, 26, 32, 38 top face
- 20, 28, 30, 34, 36, 40, 42 side face
- 22 first ring-shaped protrusion
- 24 second ring-shaped protrusion
- 161 first protrusion
- 162 second protrusion
- 163 third protrusion
- 181, 261, 262, 321, 322, 381, 382 ridge line
- L11, L12, L13, L14 virtual straight line
- PL load point
Claims (17)
1. A floor panel of an automobile comprising:
a load point to which a load is applied from the outside; and
a plurality of protrusions that protrude from a surface of the floor panel and are formed continuously around the load point,
wherein each of the plurality of protrusions intersects, at a plurality of positions, each of a plurality of virtual straight lines extending radially from the load point.
2. The floor panel according to claim 1 ,
wherein the load point is a junction with another member.
3. The floor panel according to claim 1 , comprising a plurality of the load points,
wherein at least one of density, a formation range, and a cross-sectional shape of at least two of the plurality of protrusions differ in accordance with an assumed load applied to the load point.
4. The floor panel according to claim 3 ,
wherein, at a boundary portion where protrusions formed around the corresponding plurality of load points intersect each other, side faces of the protrusions are continuous via a curved surface.
5. The floor panel according to claim 1 ,
wherein a ridge line of the one of the plurality of protrusions perpendicularly intersects the plurality of virtual straight lines.
6. The floor panel according to claim 1 ,
wherein the plurality of virtual straight lines are straight lines connecting the load point and a plurality of vertices of the floor panel.
7. The floor panel according to claim 1 , wherein each of the plurality of protrusions includes a top face parallel to the surface of the floor panel.
8. The floor panel according to claim 1 ,
wherein the plurality of protrusions are ring-shaped and are formed concentrically, and
wherein the center of the plurality of protrusions coincides with the load point.
9. The floor panel according to claim 1 ,
wherein the plurality of protrusions includes a spiral-shaped protrusion whose base point is the load point.
10. The floor panel according to claim 1 ,
wherein the floor panel is made of a steel sheet.
11. The floor panel according to claim 8 , wherein a top face of each of the plurality of protrusions has a square shape in a planar view.
12. The floor panel according to claim 8 , further comprising a plurality of triangular-shaped protrusions that are triangular-shaped in a planar view and positioned farther from the load point than each of the plurality of protrusions that are ring-shaped.
13. The floor panel according to claim 12 , wherein a top face of each of the triangular shaped protrusions have a trapezoidal shape in the planar view.
14. The floor panel according to claim 1 , wherein the ridgeline of each of the plurality of protrusions intersects all of the virtual straight lines extending radially from the load point at angles within a range of 45° to 90°.
15. The floor panel according to claim 1 , wherein a height of one of the plurality of protrusions is different from a height of another of the plurality of protrusions.
16. The floor panel according to claim 5 , wherein the top face of one of the plurality of protrusions has a width that is different from another of the plurality of protrusions.
17. The floor panel according to claim 1 , wherein an inclination angle θ of one of the plurality of protrusions is different from another inclination angle θ of another of the plurality of protrusions.
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IT202100006158A1 (en) | 2021-03-16 | 2022-09-16 | Easy House System | ROOFING MODULE FOR BUILDINGS STRONG BY SHAPE |
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FR3084323B1 (en) * | 2018-07-24 | 2020-09-18 | Psa Automobiles Sa | AUTOMOTIVE VEHICLE TOPOGRAPHIC FLOOR |
JP7411522B2 (en) * | 2020-09-04 | 2024-01-11 | 本田技研工業株式会社 | car body structure |
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2015
- 2015-03-13 US US15/116,705 patent/US10272954B2/en active Active
- 2015-03-13 CN CN201580012493.3A patent/CN106103250B/en active Active
- 2015-03-13 KR KR1020167024298A patent/KR20160117576A/en active Application Filing
- 2015-03-13 MX MX2016009373A patent/MX2016009373A/en unknown
- 2015-03-13 WO PCT/JP2015/057467 patent/WO2015137482A1/en active Application Filing
- 2015-03-13 JP JP2016507842A patent/JP6319422B2/en active Active
- 2015-03-13 KR KR1020187011186A patent/KR20180043409A/en active Application Filing
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- 2019-03-07 US US16/295,985 patent/US20190202502A1/en not_active Abandoned
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IT202100006158A1 (en) | 2021-03-16 | 2022-09-16 | Easy House System | ROOFING MODULE FOR BUILDINGS STRONG BY SHAPE |
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JPWO2015137482A1 (en) | 2017-04-06 |
US10272954B2 (en) | 2019-04-30 |
KR20180043409A (en) | 2018-04-27 |
US20160347376A1 (en) | 2016-12-01 |
CN106103250B (en) | 2019-04-05 |
WO2015137482A1 (en) | 2015-09-17 |
CN106103250A (en) | 2016-11-09 |
KR20160117576A (en) | 2016-10-10 |
JP6319422B2 (en) | 2018-05-09 |
MX2016009373A (en) | 2016-09-16 |
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