JP7448919B2 - Hollow structure and its manufacturing method - Google Patents

Description

The present invention relates to a plate-shaped hollow structure having a plurality of cells inside and a method for manufacturing the same.

Hollow structures made of synthetic resin have moderate strength, are lightweight, and are easy to handle, so they are known to be used, for example, in luggage boards that make up the floor of the luggage compartment at the rear of a vehicle. There is. The plate-shaped luggage board is placed on a mounting step above a floor panel at the rear of the vehicle, and defines a luggage storage space above the luggage board.

In order to stably place the luggage board on the mounting step, a mounting jig such as a clip may be used to fix the luggage board. In this case, you can fix the luggage board by inserting a clip into the mounting hole provided through both the luggage board and the mounting step, or insert a clip pre-installed on the luggage board into the mounting hole. It may be possible to fix the luggage board by inserting it into the provided mounting hole.

Patent Document 1 discloses that an article storage box is arranged above a spare tire storage recess formed in a floor panel at the rear of a vehicle, and a plate-shaped lid made of synthetic resin is placed above the article storage box. It is stated that the . The lid is removably fixed with a clip to a mounting portion formed in a quarter trim on a side surface of the rear part of the vehicle compartment, and forms part of the floor surface of the luggage compartment of the vehicle.

Japanese Patent Application Publication No. 2000-108792

By the way, when a plate material is attached to a mounting portion using a clip, the number of parts increases and the efficiency of the mounting work is reduced, and the clip may come off and be lost.
The present invention has been made to solve these conventional problems, and it is an object of the present invention to provide a hollow structure that is easy to install.

In order to solve the above problems, the hollow structure of the present invention includes a main body made of a hollow plate made of thermoplastic resin in which a plurality of cells are arranged in parallel, and a main body that is locked to a member to be locked. The locking portion is formed integrally with the main body by compressing the hollow plate material in the thickness direction at the peripheral edge of the main body, and the locking portion is formed integrally with the main body. includes a locking main body portion for locking the locked member, and a hinge portion rotatably connecting the locking main body portion to the main body portion.

According to the above configuration, there is no need to prepare a separate member for locking to the locked member. It is easy to attach the hollow structure to the locked member, and the workability of attaching the hollow structure is improved. Further, by rotating the locking main body, it is possible to lock the locking member provided at an appropriate position. Improved convenience. Furthermore, since the locking part for locking the member to be locked is formed by compressing the hollow plate material in the thickness direction, the density of the thermoplastic resin that makes up the hollow plate material is high in the locking part. ing. As a result, the rigidity of the locking portion is improved compared to that of the main body. It has the strength necessary to lock the member to be locked and the strength necessary when the lock main body portion rotates via the hinge portion.

In the above configuration, the locking main body part is configured to be rotatable toward the main body side via the hinge part, and the locking main body part has a structure that allows the locking main body part to rotate toward the main body side. It is preferable that a rotation regulating part is provided to regulate the rotation.

According to the above configuration, the locking portion is prevented from rotating more than necessary toward the main body portion. Therefore, the position of the locking portion is stabilized, and the attachment state of the hollow structure to the locked member is stabilized.
In the above configuration, it is preferable that the locking main body section is biased in a direction away from the main body section when the locking main body section is rotated toward the main body section via the hinge section.

According to the above configuration, the locking portion integrally formed on the periphery of the main body is biased in a direction away from the main body, so that the locking portion is biased toward the locked portion located on the side of the main body. It is firmly locked. The attachment state of the hollow structure to the locked portion located on the side of the hollow structure is stabilized.

In the above structure, a locking protrusion that locks into a locking recess of the locking member is formed at the tip of the locking body, and the locking protrusion locks the locking member. It is preferable that the main body be formed so as to protrude on the opposite side from the main body when the main body is rotated toward the main body.

According to the above configuration, the locking protrusion is locked to the locked member, thereby restricting movement of the hollow structure relative to the locked member. The locking portion is difficult to come off from the locked member, and the stable attachment state of the hollow structure is maintained.

In order to solve the above problems, the method for manufacturing a hollow structure of the present invention includes a main body made of a hollow plate made of thermoplastic resin in which a plurality of cells are arranged in parallel, and a main body formed integrally with the main body. a locking part, the locking part locking the main body to a locked member, and a locking main body that rotatably connects the locking main body to the main body. A method for manufacturing a hollow structural body comprising: a hollow plate forming step of forming the hollow plate with a concavo-convex sheet material; and press-molding the heated hollow plate to form the locking part. and a post-processing step of removing a peripheral portion of the intermediate to obtain the hollow structure.

According to the above configuration, the locking portion can be integrally formed on the hollow plate material by a press molding process. A hollow structure with excellent installation workability can be easily manufactured.

According to the present invention, a hollow structure that is easy to install can be obtained.

FIG. 2 is a perspective view of the luggage board, which is a hollow structure of the present embodiment, viewed from above. FIG. 2 is a cross-sectional view showing a locked state between a side wall of the luggage room, which is a member to be locked, and a locking portion, and a cross-sectional view showing a locked state between a portion corresponding to the α-α line in FIG. 1 and the side wall. (a) is a perspective view of a hollow plate material, (b) is a sectional view taken along the β-β line in (a), and (c) is a sectional view taken along the γ-γ line in (a). FIG. 3 is an enlarged perspective view of a locking portion. 2 is a cross-sectional view of the locking part taken along the α-α line in FIG. 1, where (a) is a cross-sectional view before the luggage board is locked, and (b) is a cross-sectional view with the luggage board locked. figure. FIG. 3 is a diagram illustrating a method for manufacturing a luggage board, and a diagram illustrating a process of forming a core layer. (a) is a perspective view of a sheet material constituting a core layer, (b) is a perspective view showing the sheet material in a state in the middle of folding, and (c) is a perspective view showing the state in which the sheet material is folded. (a) to (e) are diagrams explaining a method for manufacturing a luggage board. (a), (b) is sectional drawing explaining the state where a locking part is locked to a member to be locked. FIG. 4 is a sectional view illustrating a modification of the locking portion.

Hereinafter, a luggage board 11 embodying an embodiment of the hollow structure of the present invention will be described. The luggage board 11 forms the bottom surface of a luggage room provided at the rear of the vehicle.

As shown in FIG. 1, the luggage board 11 is formed into a substantially rectangular plate shape, and is connected to a rear plate part 13 on the rear side of the vehicle and a front plate part 14 on the front side of the vehicle via a hinge part 12 extending in the vehicle width direction. are integrally connected. The luggage board 11 is composed of a hollow plate material 10 made of thermoplastic resin in which a plurality of cells S are arranged in parallel. It is formed by thinning. When the rear plate part 13 is lifted upward using the hinge part 12 as a rotation axis, tools etc. stored in the space below the luggage board 11 can be taken in and out. Here, the upper and lower sides of the luggage board 11 refer to the upper and lower sides of the vehicle, and the surface located above the luggage board 11 is referred to as the upper surface 11a, and the surface located below is referred to as the lower surface 11b.

As shown in FIG. 2, a mounting step (not shown) is provided below the periphery of the luggage room to support the lower surface of the luggage board 11, and on both sides of the luggage room in the vehicle width direction, the luggage board 11 is mounted on the side. A pair of side walls 50 are provided to support from both sides. The luggage board 11 is placed on a mounting step (not shown) and is supported between a pair of side walls 50 facing each other in the vehicle width direction. The inner surfaces 50a of the pair of side walls 50 extend in the vertical direction. As shown in FIG. 1, the length L1 of the rear plate portion 13 of the luggage board 11 in the vehicle width direction is approximately equal to the distance between the inner surfaces 50a of the pair of side walls 50.

First, the hollow plate material 10 made of thermoplastic resin that constitutes the luggage board 11 will be described.
As shown in FIG. 3(a), the hollow plate material 10 includes a core layer 20 made of thermoplastic resin in which a plurality of cells S are arranged in parallel, and covers the entire core layer 20 on both main surfaces of the core layer 20. It is composed of skin layers 24 and 25 made of thermoplastic resin that are bonded together in a manner similar to the above. The hollow plate material 10 is arranged such that the side to which the skin layer 24 is bonded is the upper surface 11a side of the luggage board 11, and the side to which the skin layer 25 is bonded is the bottom surface 11b side of the luggage board 11, thereby forming the luggage board 11. There is.

As shown in FIG. 3A, the core layer 20 is formed by folding a thermoplastic resin sheet material molded into a predetermined shape. The core layer 20 is composed of an upper wall part 21, a lower wall part 22, and a side wall part 23 that stands between the upper wall part 21 and the lower wall part 22 and partitions the cell S into a hexagonal column shape. has been done. As explained below, the upper wall part 21 and the lower wall part 22 of the core layer have a structure in which a one-layer structure and a two-layer structure are mixed, but in FIG. The upper wall portion 21 and the lower wall portion 22 are shown as having a one-layer structure.

As shown in FIGS. 3B and 3C, the cells S defined inside the core layer 20 include a first cell S1 and a second cell S2 having different configurations. As shown in FIG. 3(b), in the first cell S1, an upper wall portion 21 having a two-layer structure is provided above the side wall portion 23. As shown in FIG. Each layer of the upper wall portion 21 of this two-layer structure is joined to each other. Furthermore, an opening (not shown) is formed in the upper wall portion 21 of the two-layer structure by heat shrinking of the thermoplastic resin during molding of the core layer 20. In the first cell S<b>1 , a lower wall portion 22 having a one-layer structure is provided below the side wall portion 23 .

On the other hand, as shown in FIG. 3(c), in the second cell S2, an upper wall portion 21 having a one-layer structure is provided above the side wall portion 23. Further, in the second cell S2, a lower wall portion 22 having a two-layer structure is provided below the side wall portion 23. Each layer of the lower wall portion 22 of this two-layer structure is joined to each other. An opening (not shown) is formed in the lower wall portion 22 of the two-layer structure by thermal contraction of the thermoplastic resin during molding of the core layer 20 .

Further, as shown in FIGS. 3(b) and 3(c), the adjacent first cells S1 and the adjacent second cells S2 are each partitioned by side wall portions 23 having a two-layer structure. There is. The side wall portion 23 having the two-layer structure has a portion in the center of the core layer 20 in the thickness direction that is not thermally welded to each other. Therefore, the internal space of each cell S of the core layer 20 communicates with the internal space of the other cells S via the side wall portions 23 of the two-layer structure.

As shown in FIG. 3A, the first cells S1 are arranged in rows along the X direction. Similarly, the second cells S2 are arranged in rows along the X direction. The rows of first cells S1 and the rows of second cells S2 are arranged alternately in the Y direction orthogonal to the X direction. The core layer 20 has a honeycomb structure as a whole due to these first cells S1 and second cells S2.

The thermoplastic resin constituting the core layer 20 and the skin layers 24 and 25 may be any conventionally known thermoplastic resin, such as polypropylene resin, polyamide resin, polyethylene resin, acrylonitrile-butadiene-styrene copolymer resin, acrylic resin, etc. resin, polybutylene terephthalate resin, etc. The core layer 20 and skin layers 24 and 25 of this embodiment are made of polypropylene resin. It is preferable that the thermoplastic resin forming the core layer 20 and the thermoplastic resin forming the skin layers 24 and 25 are made of the same material. In this embodiment, the skin layer 24 and the skin layer 25 have the same thickness.

The luggage board 11 is formed by cutting the hollow plate material 10 having such a configuration into a rectangular shape of a predetermined size. Note that in FIGS. 2, 7, and 8, the hollow structure inside the hollow plate material 10 is omitted.

As shown in FIG. 1, the luggage board 11 includes a main body portion 30 and a locking portion 40. As shown in FIG. The main body part 30 is formed into a rectangular plate shape and includes a hinge part 12, a rear plate part 13, and a part that covers almost the entire front plate part 14, and constitutes the main part of the luggage board 11. . As shown in FIGS. 4 and 5(a), a side surface 31 is formed around the entire circumference of the main body portion 30. As shown in FIGS. The side surface 31 intersects the upper surface 11a and the lower surface 11b of the luggage board 11 at an angle of approximately 45 degrees, and is formed as an inclined surface that slopes inward toward the bottom.

As shown in FIG. 1, the locking portions 40 have a shape that protrudes outward from the main body 30 in the vehicle width direction at each of both sides of the front plate 14 of the main body 30 in the vehicle width direction. It is formed integrally with 30. The locking portions 40 on both sides in the vehicle width direction have the same shape and size.

As shown in FIGS. 1 and 4, the locking portion 40 has a hinge portion 41 extending in the longitudinal direction of the vehicle, and a locking main body portion 42 connected to the main body portion 30 via the hinge portion 41. The locking body portion 42 includes, in order from the base end of the locking portion 40, a rotation restriction portion 43 that is long in the vehicle longitudinal direction, and a locking thin wall portion formed at both ends of the rotation restriction portion 43 in the vehicle longitudinal direction. 44 and a locking protrusion 45. The thin locking portions 44 and the locking protrusions 45 at both ends in the longitudinal direction of the vehicle have the same shape and size. As shown in FIG. 5(a), in the luggage board 11 before being locked to the side wall 50, the lower surface 42a of the locking body 42 is approximately flush with the lower surface 11b of the luggage board 11, and the luggage board It extends substantially parallel to the lower surface 11b of the board 11.

As shown in FIG. 5(a), the locking portion 40 has a shape in which the hollow plate material 10 constituting the main body portion 30 is thermally melted and compressed to reduce its thickness. The hinge portion 41, the rotation restriction portion 43, the thin locking portion 44, and the locking protrusion 45 have different thicknesses.

The hinge part 41 is formed to be the thinnest among the locking parts 40, and its thickness is about 1/10 of the thickness of the hollow plate material 10. In this portion, the thermoplastic resins constituting the core layer 20 and the skin layers 24 and 25 are thermally melted and compressed to be integrated, so that there is no gap. The hinge portion 41 in which the thermoplastic resin is integrated has bending elasticity to rotatably connect the locking main body portion 42 to the main body portion 30. As shown by arrow A in FIG. 5(a), in the locking portion 40, a locking main body portion 42 is rotatably connected to the main body portion 30 side about a hinge portion 41 as a rotation axis.

In the rotation restricting portion 43, inclined surfaces 43a and 43b are formed at positions on the base end side and the distal end side of the locking portion 40, which intersect with the upper surface 11a and the lower surface 11b of the luggage board 11 at an angle of about 45 degrees. has been done. As a result, the rotation regulating portion 43 has a thick portion and a thin portion, and a portion where the side wall portion 23 of the core layer 20 is hardly bent and maintains an upright state, and a portion where the side wall portion 23 of the core layer 20 is maintained in an upright state without being bent. There are also portions where the portion 23 is bent. As shown in FIGS. 5(a) and 5(b), when the locking main body portion 42 rotates in the direction of arrow A, the proximal inclined surface 43a abuts against the side surface 31 of the main body portion 30, thereby causing the locking body portion 42 to rotate in the direction of arrow A. Rotation of the stopper body portion 42 in the direction of arrow A is restricted.

As shown in FIG. 5(a), the thin locking portion 44 is formed to have the second thinnest thickness among the locking portions 40, and its thickness is approximately 1/5 of the thickness of the hollow plate 10. be. In this part, the thermoplastic resins constituting the core layer 20 and the skin layers 24 and 25 are thermally melted and compressed to be integrated, and a slight gap is formed in the integrated thermoplastic resin. It becomes. The thin locking portion 44 has a certain degree of bending elasticity. The upper surface 44a of the thin locking portion 44 is formed to be parallel to the upper surface 11a and the lower surface 11b of the luggage board 11.

The locking protrusion 45 is formed to be the third thinnest among the hollow plate members 10, and its thickness is approximately 1/2 to 2/3 of the thickness of the hollow plate member 10. In this part, a part where the side wall part 23 of the core layer 20 is bent and a part where the thermoplastic resin constituting the core layer 20 and the skin layers 24 and 25 are thermally melted and integrated are in a mixed state. ing. The proximal surface 45a of the locking protrusion 45 extends vertically perpendicularly to the top surface 44a of the thin locking portion 44, and the top surface 45b of the locking protrusion 45 is connected to the top surface 11a of the luggage board 11 and It is formed parallel to the lower surface 11b. Further, the distal end surface 45c of the locking projection 45 extends in the vertical direction so as to be parallel to the proximal end surface 45a, and a curved surface 45d having an R-shaped cross section is formed between the distal end surface 45c and the upper surface 45b. has been done.

As shown in FIG. 5(a), when the locking main body portion 42 is rotated in the direction of arrow A about the hinge portion 41, the inclined surface 43a formed on the rotation restriction portion 43 By coming into contact with the side surface 31 of the main body part 30, the locking main body part 42 is restricted from further rotation. As shown in FIG. 5(b), the side surface 31 of the main body part 30 and the inclined surface 43a of the rotation restriction part 43 are arranged to intersect with the upper surface 11a and the lower surface 11b of the luggage board 11 at an angle of about 45 degrees. Since the locking main body portion 42 is formed as an inclined surface that is inclined at a right angle, when the inclined surface 43 a comes into contact with the side surface 31 , the locking main body portion 42 becomes perpendicular to the main body portion 30 . A force is applied to the locking main body portion 42 rotated in the direction of arrow A, which urges it in the direction of arrow B, which is the opposite direction to the direction of arrow A and in the direction of moving away from the main body portion 30. do.

As shown in FIG. 2, a recess 51 is formed in each of the inner surfaces 50a of the pair of side walls 50 to which the luggage board 11 is locked. The recess 51 is formed to be slightly deeper than the protruding length of the locking protrusion 45 from the upper surface 44a of the thin locking part 44, and is slightly deeper than the protruding length of the locking protrusion 45 from the upper surface 44a of the thin locking part 44. It is formed in a large size. The luggage board 11 is locked between the pair of side walls 50 by the locking protrusion 45 being accommodated in the recess 51 of the side wall 50 when the locking main body portion 42 is rotated in the direction of arrow A. be stopped. The side wall 50 is a locked member in the claims, and the recess 51 is a locked recess in the claims.

Next, a method for manufacturing the luggage board 11 will be described based on FIGS. 6 and 7.
The method for manufacturing the luggage board 11 includes a hollow plate forming process, a heating process, a press molding process, and a post-processing process. The hollow plate forming step is a step of forming the core layer 20 from one sheet material 100 and joining the skin layers 24 and 25 to the core layer 20. The heating process is a process of heating the hollow plate material 10. The press molding process is a process in which the hollow plate material 10 is molded within the mold 70 to obtain the intermediate body 60. The post-processing process is a process of processing the intermediate body 60 to obtain the luggage board 11.

As shown in FIGS. 6(a) to 6(c), in the hollow plate forming step, first, the core layer 20 is formed by folding the sheet material 100.
As shown in FIG. 6(a), the sheet material 100 is formed by molding one thermoplastic resin sheet into a predetermined shape. In the sheet material 100, band-shaped planar regions 110 and bulging regions 120 are arranged alternately in the longitudinal direction (X direction) of the sheet material 100. In the bulging region 120, a first bulging portion 121 having a downward groove shape in cross section and consisting of an upper surface and a pair of side surfaces is formed over the entire length of the bulging region 120 in the extending direction (Y direction). Note that the angle between the top surface and the side surface of the first bulging portion 121 is preferably 90 degrees, and as a result, the cross-sectional shape of the first bulging portion 121 has a downward U-shape. Further, the width of the first bulging portion 121 (the length in the lateral direction of the upper surface) is equal to the width of the plane area 110, and the bulging height of the first bulging portion 121 (the length in the lateral direction of the side surface) is equal to the width of the plane area 110. ) is set to be twice the length.

Further, in the bulging region 120, a plurality of second bulging portions 122 each having a trapezoidal cross-sectional shape obtained by bisecting a regular hexagon with the longest diagonal line are arranged so as to be orthogonal to the first bulging portion 121. It is formed. The height of the second bulge 122 is set to be equal to the height of the first bulge 121 . Furthermore, the interval between adjacent second bulges 122 is equal to the width of the upper surface of the second bulges 122 .

Note that the first bulging portion 121 and the second bulging portion 122 are formed by partially bulging the sheet upward using the plasticity of the sheet. Moreover, the sheet material 100 can be molded from one sheet by a well-known molding method such as a vacuum forming method or a compression molding method.

As shown in FIGS. 6A and 6B, the core layer 20 is formed by folding the sheet material 100 configured as described above along the boundary lines P and Q. Specifically, the sheet material 100 is valley-folded along the boundary line P between the flat area 110 and the bulging area 120, and mountain-folded along the boundary line Q between the top surface and the side surface of the first bulging part 121. compress it in the X direction. As shown in FIGS. 6(b) and 6(c), the upper surface and side surface of the first bulging portion 121 are folded together, and the end surface of the second bulging portion 122 and the plane area 110 are folded over each other. One prismatic partition body 130 extending in the Y direction is formed for each bulging region 120 . A hollow plate-shaped core layer 20 is formed by continuously forming such partitions 130 in the X direction.

When the sheet material 100 is compressed as described above, the upper wall portion 21 of the core layer 20 is formed by the upper surface and side surfaces of the first bulging portion 121, and the end surface and the plane area 110 of the second bulging portion 122 are formed. The lower wall portion 22 of the core layer 20 is formed by this. As shown in FIG. 6(c), a portion of the upper wall portion 21 where the upper surface and side surface of the first bulging portion 121 overlap to form a two-layer structure, and a portion of the second bulging portion of the lower wall portion 22. The portions where the end surfaces of 122 and the plane region 110 are folded to form a two-layer structure become overlapping portions 131, respectively.

Further, the hexagonal column-shaped area formed by folding the second bulging portion 122 becomes the second cell S2, and the hexagonal column-shaped area partitioned and formed between the pair of adjacent partition bodies 130 becomes the second cell S2. One cell becomes S1. In the present embodiment, the upper surface and the side surface of the second bulging portion 122 constitute the side wall portion 23 of the second cell S2, and the side surface of the second bulging portion 122 and the second bulging portion 122 in the bulging region 120 constitute the side wall portion 23 of the second cell S2. The plane portion located in between constitutes the side wall portion 23 of the first cell S1. The contact area between the upper surfaces of the second bulging part 122 and the contact area between the flat parts of the bulge area 120 form the side wall part 23 having a two-layer structure. In addition, when implementing such a folding process, it is preferable that the sheet material 100 is heat-treated and softened.

Subsequently, the skin layer 24 is superposed on the upper surface of the core layer 20, and the skin layer 25 is superposed on the lower surface of the core layer 20. The skin layers 24 and 25 are preferably heated and softened. By heat-treating the skin layers 24 and 25, the thermoplastic resin adhesive layer coated on the skin layers 24 and 25 is partially thermally melted. Therefore, the skin layers 24 and 25 superimposed on the core layer 20 are positioned while being temporarily joined to the core layer 20. The adhesive layer is solidified by the temperature drop of the core layer 20 and the skin layers 24 and 25, and the skin layers 24 and 25 are bonded to the core layer 20 to form the hollow plate material 10.

Next, a heating process for heating the hollow plate material 10 will be explained.
As shown in FIG. 7A, first, as the hollow plate material 10 to be used for the luggage board 11, a previously manufactured hollow plate material 10 is cut into a shape slightly larger than the luggage board 11. Specifically, a board cut into a substantially rectangular shape, which is about 50 mm larger than the luggage board 11 in both the longitudinal and lateral directions, is prepared. Note that the shapes, sizes, etc. of the hollow plate 10, the intermediate body 60, and the luggage board 11 differ from the actual ones, and necessary parts are exaggerated. 7(b) to (e), only the portions of the mold 70, the intermediate body 60, and the luggage board 11 corresponding to the α-α line in FIG. 1 are shown.

In the heating step, the hollow plate material 10 is placed in a heating furnace H set at a predetermined temperature and held for a predetermined time. The temperature in the heating furnace H is set to such a level that the thermoplastic resin constituting the hollow plate material 10 is melted.

Next, a press molding process for molding the hollow plate material 10 to obtain the intermediate body 60 will be described.
As shown in FIG. 7(b), a mold 70 used in the press molding process includes an upper mold 71 and a lower mold 72. The upper mold 71 and the lower mold 72 of this embodiment are kept at room temperature without being heated as a whole. Although the shapes of the upper mold 71 and the lower mold 72 correspond to the shape of the luggage board 11, only the portion of the luggage board 11 corresponding to the locking portion 40 will be described here. In a portion corresponding to the hinge portion 12, a convex portion (not shown) in the shape of the hinge portion 12 is formed on the lower mold 72.

As shown in FIG. 7(b), the lower mold 72 is formed with recesses 72a, 72b, and a convex portion 72c. The recessed portion 72a is a portion forming the outer side of the main body portion 30 of the luggage board 11, and is formed to have the size and shape of the luggage board 11. The recessed portion 72b is a portion for forming the locking body portion 42 of the locking portion 40 in the intermediate body 60. The convex portion 72c is a portion for forming the hinge portion 41 of the locking portion 40.

The upper die 71 is formed with recesses 71a, 71b and a protrusion 71c. The recessed portion 71a is a portion for forming the main body portion 30 of the luggage board 11 and the rotation restriction portion 43 of the locking portion 40. The recessed portion 71b is a portion for forming the locking protrusion 45 of the locking portion 40. The convex portion 71c is a portion for forming the thin locking portion 44 of the locking portion 40.

As shown in FIG. 7(b), first, the heated hollow plate material 10 is placed on the lower mold 72. As shown in FIG. At this time, the hollow plate material 10 is in a state in which the peripheral edge thereof slightly protrudes outward from the recesses 72a and 72b.

As shown in FIG. 7(c), a cavity is formed by clamping the upper mold 71 and the lower mold 72. Pressure and pressing time during pressing may be set appropriately. The hollow plate material 10 is formed into a cavity shape to become an intermediate body 60.

As shown in FIG. 7(c), in the intermediate body 60, the core layer 20 is almost compressed in the thickness direction in the recess 71a of the upper mold 71 and the recess 72a of the lower mold 72 during mold clamping. Never. Further, the thermoplastic resin that constitutes the core layer 20 hardly melts. The core layer 20 does not deform in the vertical direction, maintains its height dimension, and maintains the honeycomb structure of the core layer 20. This maintains the strength of the honeycomb structure.

In the intermediate body 60, in the convex portion 71c of the upper mold 71 and the recessed portion 72b of the lower mold 72, the thermoplastic resin constituting the core layer 20 and the skin layers 24, 25 is thermally melted during mold clamping. By being compressed, a portion of the luggage board 11 corresponding to the hinge portion 41 is formed. The thermoplastic resin constituting the upper wall 21, lower wall 22, and side wall 23 of the core layer 20 was thermally melted, and the thermoplastic resins constituting the skin layers 24 and 25 were thermally melted and integrated. state.

In the intermediate body 60, the thermoplastic resin constituting the core layer 20 and the skin layers 24 and 25 is thermally melted in the recess 72b of the lower mold 72 located outside the recess 71b of the upper mold 71 during mold clamping. The compressed portion 61 is molded by being compressed. In the compressed portion 61, the thermoplastic resin forming the upper wall 21, the lower wall 22, and the side wall 23 of the core layer 20 is thermally melted, and the thermoplastic resin forming the skin layers 24 and 25 is thermally melted. It becomes an integrated state.

In the intermediate body 60, in the convex portion 71c of the upper mold 71 and the recessed portion 72b of the lower mold 72, the side wall portion 23 of the core layer 20 is compressed and bent in the vertical direction during mold clamping, and the core A portion corresponding to the locking protrusion 45 is molded in a state in which a portion in which the thermoplastic resin constituting the layer 20 and the skin layers 24 and 25 is thermally melted and integrated is mixed together. In the locking protrusion 45, the melted and integrated thermoplastic resin is mixed with the melted and integrated thermoplastic resin with a slight gap left, and the density of the thermoplastic resin becomes higher than the density of the hollow plate material 10.

In the intermediate body 60, in the recessed part 71a of the upper mold 71 and the recessed part 72b of the lower mold 72, a part corresponding to the rotation regulating part 43 is molded, where the state of the thermoplastic resin differs depending on the part depending on the mold clamping. . Specifically, a portion where the side wall portion 23 of the core layer 20 is compressed and bent in the vertical direction, and a portion where the thermoplastic resins forming the core layer 20 and the skin layers 24 and 25 are thermally melted and integrated. The ratio of these changes depending on the height of the cavity. The lower the height of the cavity, the greater the proportion of the thermoplastic resin constituting the core layer 20 and the skin layers 24 and 25 that is thermally melted and integrated.

As shown in FIG. 7D, after the upper mold 71 is separated from the lower mold 72, the intermediate body 60 is taken out from the lower mold 72. In the intermediate body 60 obtained through the press molding process, a compressed portion 61 is formed over the entire circumference of a portion having a size corresponding to the luggage board 11.

Next, a post-processing process for processing the intermediate body 60 to obtain the luggage board 11 will be described. In the post-processing step, the compressed portion 61 at the peripheral edge of the intermediate body 60 is cut off to adjust the shape of the side surface.
As shown in FIGS. 7(d) and (e), the compressed portion 61 formed in the intermediate body 60 is cut with a cutting jig (not shown). After the compressed portion 61 is cut, the shape of the luggage board 11 is adjusted by polishing, painting, etc. Note that when a Thomson blade, laser, or the like is used as a cutting jig for cutting the compressed portion 61, polishing, painting, etc. do not necessarily have to be performed.

Through the above steps, the luggage board 11 is obtained.
Next, the function of the luggage board 11 of this embodiment will be explained based on FIG. 8.
The locking main body portion 42 of the luggage board 11 is rotatable toward the main body portion 30 using the hinge portion 41 as a rotation axis, as shown by arrow A in FIG. 5(a). As shown in FIG. 8(a), when the luggage board 11 is pushed downward with the locking body 42 of the luggage board 11 slightly rotated toward the body 30, the locking body 42 is moved downward. , a portion of the locking protrusion 45 from the curved surface 45d to the upper surface 45b moves downward along the side wall 50. The pressing force on the luggage board 11 acts as a force that rotates the locking main body portion 42 in the direction of arrow A. Since the curved surface 45d has an R-shaped cross section, the luggage board 11 smoothly moves downward.

As shown in FIG. 8(b), when the locking main body part 42 is rotated toward the main body part 30 side, the inclined surface 43a formed on the rotation regulating part 43 of the locking main body part 42 is rotated toward the main body part 30. The lock main body portion 42 is restricted from further rotation. Therefore, when the locking protrusion 45 moves downward along the inner surface 50a above the recess 51 of the side wall 50, the locking main body 42 is held in a state perpendicular to the main body 30. move while On the other hand, the locking thin wall portion 44 provided on the base end side of the locking protrusion 45 has a certain degree of bending elasticity. Therefore, the locking protrusion 45 moves to the recess 51 along the inner surface 50a of the side wall 50 while being allowed to bend toward the main body 30 to some extent.

As shown in FIG. 8(b), the locking main body 42 rotated in the direction of arrow A has a direction opposite to the direction of arrow A and a direction of arrow B separating from the main body 30. A force is acting on the Therefore, when the locking protrusion 45 reaches the position of the recess 51, the locking protrusion 45 is housed in the recess 51 by the biasing force in the direction of arrow B. At this time, the upper surface 44a of the thin locking portion 44 contacts the inner surface 50a above the recess 51 of the side wall 50, and the base end surface 45a of the locking protrusion 45 contacts the upper surface 51a of the recess 51 of the side wall 50. The locking protrusion 45 is held within the recess 51 with its movement restricted by the force urging the locking body 42 in the direction of arrow B.

Furthermore, a recess 51 is formed in each of the inner surfaces 50a of the pair of side walls 50, and the luggage board 11 is configured such that the length L1 of the main body 30 in the vehicle width direction is approximately equal to the interval between the pair of side walls 50. It is formed. Therefore, the luggage board 11 is firmly held between the pair of side walls 50 with the locking protrusions 45 formed on both sides in the vehicle width direction accommodated in the recesses 51 of the pair of side walls 50.

According to the luggage board 11 of this embodiment, the following effects can be obtained.
(1) The luggage board 11 is composed of a hollow plate material 10 made of thermoplastic resin in which a plurality of cells S are arranged in parallel, and a locking part 40 for locking to a side wall 50 as a locked member is provided. , are integrally formed on the periphery of the main body portion 30.

Therefore, there is no need to prepare a separate member for locking to the locked member. It is easy to attach the hollow structure to the locked member, and the workability of attaching the hollow structure is improved.
(2) The locking portion 40 includes a hinge portion 41 and a locking body portion 42, and the locking body portion 42 is rotatably connected to the body portion 30 via the hinge portion 41.

Therefore, by rotating the locking main body part 42, it can be easily locked to the side wall 50 provided on the side of the main body part 30.
(3) The locking portion 40 is formed by compressing the hollow plate material 10 that constitutes the main body portion 30 in the thickness direction.

Therefore, in the locking portion 40, the density of the thermoplastic resin constituting the hollow plate member 10 is high, and the rigidity of the locking portion 40 is improved compared to the main body portion 30. It has the strength necessary to lock onto the side wall 50. In addition, it has the strength necessary when the locking main body portion 42 rotates via the hinge portion 41.

(4) The locking main body part 42 is provided with a rotation regulating part 43 in which an inclined surface 43a is formed, and when the inclined surface 43a comes into contact with the side surface 31 of the main body part 30, the rotation regulating part 43 The rotation of the locking body portion 42 is restricted.

Therefore, the locking portion 40 is prevented from rotating more than necessary toward the main body portion 30, and the position of the locking portion 40 is stabilized. The attachment state of the luggage board 11 to the side wall 50 is stabilized.
(5) The side surface 31 of the main body portion 30 and the inclined surface 43a of the rotation restriction portion 43 are both inclined to intersect with the upper surface 11a and lower surface 11b of the luggage board 11 at approximately 45 degrees.

Therefore, when the locking body 42 rotates and the side surface 31 and the inclined surface 43a come into contact, the locking body 42 becomes perpendicular to the body 30. As a result, the locking main body portion 42 is held along the side wall 50 extending in the vertical direction, thereby stabilizing the locked state of the locking main body portion 42 with respect to the side wall 50.

(6) When the locking body portion 42 is rotated toward the body portion 30 via the hinge portion 41, it is urged in the direction of arrow B away from the body portion 30.
Therefore, the locking main body portion 42 is firmly locked in the recesses 51 of the pair of side walls 50 provided on both sides of the luggage room in the vehicle width direction.

(7) A locking protrusion 45 that locks into the recess 51 of the side wall 50 is formed at the distal end of the locking body 42 . It is formed so as to protrude to the side opposite to the main body portion 30 when rotated to the side.

Therefore, when the locking protrusion 45 is locked in the recess 51, upward movement of the luggage board 11 relative to the side wall 50 is restricted. The locking portion 40 is difficult to come out of the recess 51, and the stable attachment state of the luggage board 11 is maintained.

(8) The base end surface 45a of the locking protrusion 45 comes into contact with the upper surface 51a of the recess 51 while the luggage board 11 is locked to the side wall 50.
Therefore, not only the upward movement of the luggage board 11 is restricted, but also the rattling of the locking protrusion 45 within the recess 51 is suppressed.

(9) The upper surface 44a of the locking thin wall portion 44 contacts the inner surface 50a of the side wall 50 while the luggage board 11 is locked to the side wall 50.
Therefore, the locking thin wall portion 44 is unlikely to wobble between the inner surfaces 50a of the pair of side walls 50, and the mounting state of the luggage board 11 is stabilized.

(10) The locking protrusion 45 of the locking body portion 42 is formed with a curved surface 45d having an R-shaped cross section that smoothly connects the tip end surface 45c and the upper surface 45b.
Therefore, when attaching the luggage board 11, the outer surface of the locking protrusion 45 tends to follow the inner surface 50a of the side wall 50. The luggage board 11 can be attached smoothly.

(11) In the locking thin wall portion 44 of the locking main body portion 42, the thermoplastic resin constituting the core layer 20 and the skin layers 24, 25 is thermally melted and compressed to be integrated. A slight gap is formed in the resin.

Therefore, the thin locking portion 44 has a certain degree of bending elasticity, allowing the locking body portion 42 to bend when the locking protrusion 45 moves along the inner surface 50a of the side wall 50. The luggage board 11 can be attached smoothly.

(12) In the rotation regulating portion 43 of the locking main body portion 42, the side wall portion 23 of the core layer 20 is compressed and bent in the vertical direction, and the thermoplastic material forming the core layer 20 and the skin layers 24, 25 The resin is in a mixed state with a part where the resin is thermally melted and integrated.

Therefore, the density of the thermoplastic resin in the rotation regulating part 43 is higher than that of the hollow plate material 10, and when the inclined surface 43a of the rotation regulating part 43 comes into contact with the side surface 31 of the main body part 30, the rotation The strength of the regulating portion 43 is maintained.

(13) In the locking protrusion 45 of the locking body 42, the thermoplastic resin constituting the core layer 20 and the skin layers 24 and 25 is thermally melted and integrated, leaving a slight gap. It is in a mixed state with parts that have changed.

Therefore, the density of the thermoplastic resin in the locking protrusion 45 is higher than that of the hollow plate material 10, and the rigidity when the locking protrusion 45 is locked in the recess 51 is maintained.
(14) In parts other than the locking part 40 and the hinge part 12 of the luggage board 11, the thermoplastic resin constituting the core layer 20 of the hollow plate material 10 is hardly melted. Further, the core layer 20 does not deform in the vertical direction, but maintains its height dimension, and the honeycomb structure of the core layer 20 is maintained.

Therefore, the honeycomb structure of the core layer 20 is maintained over almost the entire luggage board 11, and the strength of the honeycomb structure is maintained.
(15) The length L1 of the main body portion 30 of the luggage board 11 in the vehicle width direction is formed to be equal to the distance between the inner surfaces 50a of the pair of side walls 50.

Therefore, the rattling of the luggage board 11 locked to the side wall 50 is suppressed, and the locked state is stabilized.
(16) The locking portion 40 is molded simultaneously when the intermediate body 60 is molded in a press molding process.

Therefore, the locking portion 40 can be easily formed.
Note that the above embodiment can be modified and implemented as follows. Each embodiment and the following modification examples can be implemented in combination with each other within a technically consistent range.

- The locking portion 40 of the above embodiment includes a hinge portion 41 and a locking body portion 42, and the locking body portion 42 includes, in order from the proximal end, a rotation regulating portion 43, a thin locking portion 44, and a locking body portion 42. Although a locking protrusion 45 is formed, the configuration and shape of the locking body 42 are not limited thereto.

- At least one of the rotation restricting portion 43 and the thin locking portion 44 may not be formed.
- In the locking part 40 of the above embodiment, the thickness of the hinge part 41 is about 1/10 of the thickness of the hollow plate 10, the thickness of the thin locking part 44 is about 1/5 of the thickness of the hollow plate 10, and the thickness of the locking part 44 is about 1/5 of the thickness of the hollow plate 10. Although the thickness of the stopper projection 45 is approximately 1/2 to 2/3 of the thickness of the hollow plate 10, the present invention is not limited thereto. It may be thicker or thinner than this. It can be modified as appropriate to the extent that functions such as rigidity, strength, and bending elasticity required for each part can be achieved.

- The side surface 31 of the main body part 30 may be formed to be perpendicular to the upper surface 11a and the lower surface 11b of the luggage board 11. In this case, by forming the rotation restriction part 43 into a thin plate shape that is slightly thicker than the hinge part 41, the rotation restriction part abutting against the side surface 31 of the main body part 30 is perpendicular to the main body part 30. The situation will be as follows.

- The lock main body portion 42 does not need to be biased in the direction of arrow B while being rotated in the direction of arrow A.
- The locking part 40 of the above embodiment has a shape in which a locking thin part 44 and a locking protrusion 45 are connected in two places in the vehicle longitudinal direction with respect to a rotation regulating part 43 that is long in the vehicle longitudinal direction. However, the shape of the locking portion 40 is not limited to this. For example, the lock body portion 42 is formed such that the rotation restricting portion 43, the thin lock portion 44, and the lock protrusion 45 are all the same length in the vehicle longitudinal direction, and the lock body portion 42 is located at two locations in the forward direction of the vehicle. may be formed.

- The locking thin wall portion 44 and the locking protrusion 45 may be formed at three or more locations in the vehicle longitudinal direction instead of at two locations. Alternatively, it may be formed at one location.
- As shown in FIG. 9, the locking protrusion 45 may be formed so as to protrude toward the main body 30 when the locking main body 42 is rotated toward the main body 30. In this case, a locked member 52 is erected inside a pair of side walls 50 that support the luggage board 11 from the side so as to face the side walls 50. It is preferable that the locked recesses 53 are formed at opposing positions.

- The luggage board 11 may have an uneven shape in addition to the locking part 40 and the hinge part 12. For example, the lower surface 11b of the luggage board 11 may have an uneven shape so as to absorb the uneven shape of a vehicle structure located below the luggage board 11.

- The luggage board 11 does not have to be a flat plate, and may be, for example, a curved plate.
- The luggage board 11 is not limited to a rectangular plate shape. It can be changed as appropriate depending on the shape of the vehicle to which it is applied.

- The hollow structure of the present invention can be applied to things other than the luggage board 11. As long as it is locked to a member to be locked, it may be applied to, for example, a shelf board or the like.
- As the hollow plate material 10 constituting the luggage board 11, one in which at least one of the skin layers 24 and 25 is not bonded may be used.

- Although the skin layers 24 and 25 have a single layer structure, they may have a multilayer structure.
- Although the skin layers 24 and 25 of the hollow plate material 10 are made of a sheet material made of thermoplastic resin, at least one of them may be made of a nonwoven fabric. When the skin layers 24 and 25 are made of nonwoven fabric, one surface can be coated with an adhesive layer made of thermoplastic resin (eg, polypropylene resin) and bonded to the core layer 20 via the adhesive layer. The nonwoven fabric constituting the skin layers 24 and 25 can be made of various conventionally known fibers such as polyamide fibers, aramid fibers, cellulose fibers, polyester fibers, polyethylene fibers, polypropylene fibers, rayon fibers, and glass fibers. When both the skin layers 24 and 25 are made of nonwoven fabric, the skin layer 24 and the skin layer 25 may have the same structure or different structures.

- The skin layers 24 and 25 may be printed on a resin film. The design of the luggage board 11 can be improved.
- Although the skin layers 24 and 25 are bonded to the core layer 20 via an adhesive layer, the adhesive layer may be omitted. Even in this case, the thermoplastic resins forming the core layer 20 and the skin layers 24 and 25 are partially melted and bonded to each other.

- The core layer 20 is not limited to being formed by folding and forming one sheet material 100. For example, a plurality of belt-shaped sheets may be arranged bent at predetermined intervals to constitute the side walls of the cell, and sheet layers may be arranged on both sides of the upper and lower sides of these belt-shaped sheets to constitute the upper and lower walls of the cell. You may also do so.

- In the above embodiment, hexagonal columnar cells S are defined inside the core layer 20, but the shape of the cells S is not particularly limited. For example, it may be a polygonal shape such as a quadrangular prism shape or an octagonal prism shape, or a cylindrical shape. Further, the shape of the cell S may be a prefixed conical shape. At this time, cells of different shapes may be mixed. Further, the cells do not need to be adjacent to each other, and a gap (space) may exist between the cells.

- The core layer 20 is not limited to one in which columnar cells S are partitioned. For example, sheet layers may be bonded to both upper and lower surfaces of a core layer having a predetermined uneven shape. Examples of the core layer having such a configuration include the one described in JP-A No. 2014-205341. Alternatively, a plastic cardboard or the like having a harmonica-shaped cross section may be used.

- In the above embodiment, a single sheet material 100 is folded and formed to form the core layer 20 as a honeycomb structure in which hexagonal cells S are sectioned inside the core layer 20, but the forming method is different. It is not limited to this. For example, as described in Japanese Patent No. 4368399, the core layer 20 as a honeycomb structure may be formed by sequentially folding a three-dimensional structure in which a plurality of rows of convex portions having a trapezoidal cross section are provided. good.

- As the thermoplastic resin constituting the core layer 20 and the skin layers 24 and 25, one to which various functional resins are added may be used. For example, flame retardancy can be increased by adding a flame retardant resin to a thermoplastic resin. It is also possible to use a material to which various functional resins are added to all of the core layer 20 and skin layers 24 and 25, and it is also possible to use it for at least one of the core layer 20 and skin layers 24 and 25. It is also possible to do so.

- The upper mold 71 and the lower mold 72 used in the press molding process may have a plurality of suction holes formed therein. In this case, the shape and position of the suction hole are not particularly limited.
- Although the upper mold 71 and the lower mold 72 were kept at room temperature without being heated as a whole, the upper mold 71 and the lower mold 72 may be heated.

The technical concept understood from the above embodiment and modification examples will be described.
(a) A main body made of a hollow plate made of thermoplastic resin in which a plurality of cells are arranged in parallel, and a locking part for locking the main body to a member to be locked, the main body The locking portion formed by compressing the hollow plate material in the thickness direction is formed integrally with the main body portion, and the density of the thermoplastic resin constituting the locking portion is the same as that of the hollow plate material. The locking portion includes a locking body portion for locking to a locked member, and a locking body portion rotatably connecting the locking body portion to the main body portion. A hollow structure characterized by comprising a hinge part.

10...Hollow board material 11...Luggage board (hollow structure)
30... Main body part 40... Locking part 41... Hinge part 42... Locking main body part 43... Rotation regulating part 45... Locking protrusion 50... Side wall (locked member)
51... Recess (locked recess)
52...Locked member 53...Locked recess S...Cell

Claims (5)

A main body made of a hollow plate made of thermoplastic resin in which a plurality of cells are arranged in parallel, and a locking part for locking the main body to a locked member,
The locking portion, which is formed by compressing the hollow plate material in its thickness direction, is formed integrally with the main body at a peripheral edge of the main body,
The locking portion includes a locking main body portion for locking the locked member, and a hinge portion rotatably connecting the locking main body portion to the main body portion. hollow structure. The locking main body part is configured to be rotatable toward the main body part via the hinge part,
2. The hollow structure according to claim 1, wherein the locking main body is provided with a rotation restricting portion that restricts rotation of the locking main body toward the main body. The hollow lock according to claim 1 or 2, wherein the locking main body section is biased in a direction away from the main body section when the locking main body section is rotated toward the main body section via the hinge section. Structure. A locking protrusion that locks into a locking concave portion of the locking member is formed at the tip of the locking body,
The locking protrusion is formed so as to protrude on the opposite side of the main body when the locking main body is rotated toward the main body. 3. The hollow structure according to any one of 3. The main body includes a hollow plate made of thermoplastic resin in which a plurality of cells are arranged in parallel, and a locking portion integrally formed with the main body, and the locking portion is connected to the main body. A method for manufacturing a hollow structure comprising: a locking main body portion that locks the locking body portion to a locked member; and a hinge portion rotatably connecting the locking main body portion to the main body portion, the method comprising:
a hollow plate forming step of forming the hollow plate with a concavo-convex sheet material;
a press molding step of press molding the heated hollow plate material to form an intermediate body having the locking part;
A method for manufacturing a hollow structure, comprising a post-processing step of removing a peripheral portion of the intermediate to obtain the hollow structure.