JP7155923B2 - Molded product manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing molded articles.

Automotive structural members (particularly long members) are required to have high properties in a three-point bending test in order to improve collision safety performance. Therefore, various proposals have conventionally been made.

The drawings of Patent Document 1 and Patent Document 2 disclose impact absorbing members including a portion where a steel plate is folded three times.

Patent Literature 3 discloses a hollow columnar component in which a connection region between a vertical wall portion and a ceiling wall portion protrudes outward. To increase the number of ridges in the cross-section, the overhang is not folded over.

Patent Literature 4 discloses a method of manufacturing a cross-sectional hat-shaped component in which a groove-shaped bead portion is formed along the longitudinal direction on a vertical wall portion.

Patent Literature 5 discloses a hot-stamped article formed of a single steel sheet and having protrusions in which the steel sheets partially overlap each other, and a method of manufacturing the same.

Japanese Patent Application Laid-Open No. 2008-265609 Japanese Patent Application Laid-Open No. 2008-155749 Japanese Patent Application Laid-Open No. 2011-67841 Japanese Patent Application Laid-Open No. 2011-83807 WO2018/012603

The techniques described in Patent Documents 1 to 5 above aim to improve impact characteristics and compression characteristics compared to conventional hat-shaped structural members, and press-formed products with high strength and higher characteristics in a three-point bending test. is obtained in some cases.
However, at present, there is a demand for structural members for automobiles such as side sills, which can further improve collision safety performance. In other words, there is a demand for a press-formed product with higher strength and higher properties in a three-point bending test.

In recent years, along with the demand for energy saving, etc., there has been a demand for automobile components that are smaller and lighter while maintaining conventional performance. Therefore, structural members for automobiles are also required to have better formability.

One of the objects of the present invention, which has been made in view of such circumstances, is to provide a molded product having high strength and excellent characteristics in a three-point bending test, and a structural member using the same.
Another object of the present invention is to provide a production method for producing a molded article that has good moldability, high strength, and excellent properties in a three-point bending test.

(1 ) A method for manufacturing a molded product according to an aspect of the present invention includes a vertical wall portion formed of a metal plate, a projecting portion, and a top plate portion adjacent to the vertical wall portion via the projecting portion. , in the projecting portion, an overlapping portion where a portion of the metal plate extending from the top plate portion and a portion of the metal plate extending from the vertical wall portion overlap; and an sandwiching portion sandwiched between the metal plates forming the overlapping portion; A method for manufacturing a long molded product having an end portion in which a metal plate forming an overlapping portion is bent, comprising an upper mold, a lower mold, and a moving mold that can move vertically and horizontally. The lower die includes a punch die and a movable plate arranged to sandwich the punch die and movable at least in the vertical direction, and a material metal having a portion corresponding to the sandwiching portion serving as a sandwiching portion (Ia) placing the material metal plate between the upper mold, the moving mold and the lower mold in a state where the punch die and the material metal plate are not in contact with each other; and (Ib) moving the moving die. (IIa) moving the moving die further toward the punching die to obtain a deformed metal sheet by bringing the edge of the material metal sheet closer to the punching die by lowering it together with the movable plate and moving it toward the punching die; (IIb) a step of restraining a part of the deformed metal plate by the moving die and the side face of the punch while maintaining a state in which the upper face of the punch die and the deformed metal plate are not in contact with each other; constraining the portion of the deformed metal sheet by the upper die and the punch die by lowering the die, by overlapping the portion of the deformed metal sheet between the upper die and the moving die. The projecting portion is formed by sandwiching the portion corresponding to the sandwiching portion.
By the method for producing a molded article having the above configuration, a molded article having good moldability, high strength, and excellent properties in a three-point bending test can be obtained.

According to the present invention, a molded article having high strength and excellent properties in a three-point bending test, and a structural member using the same can be obtained. Furthermore, according to the manufacturing method of the present invention, the molded product can be easily manufactured while having good moldability.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows typically an example of the molded product of 1st Embodiment. FIG. 2 is a cross-sectional view schematically showing the molded product shown in FIG. 1; FIG. 4 is a schematic cross-sectional view for explaining the projecting portion of the molded product of the first embodiment; FIG. 4 is a schematic cross-sectional view for explaining the projecting portion of the molded product of the first embodiment; It is a typical sectional view for explaining a modification of a projection part of a cast of a 1st embodiment. It is a typical sectional view for explaining a modification of a projection part of a cast of a 1st embodiment. FIG. 10 is a schematic cross-sectional view for explaining the projecting portion of the molded product of the second embodiment; FIG. 11 is a schematic cross-sectional view for explaining a projecting portion of a molded product of a third embodiment; Fig. 2 is a perspective view schematically showing another example of the molded product according to the present invention; Fig. 2 is a perspective view schematically showing another example of the molded product according to the present invention; 1 is a perspective view schematically showing a material steel plate according to the present invention; FIG. FIG. 12 is a cross-sectional view schematically showing the material steel plate shown in FIG. 11; FIG. 11 is a cross-sectional view schematically showing an example of a preform formed in the manufacturing method of the fourth embodiment; It is a sectional view showing typically one process in the 2nd process in an example of a manufacturing method of a 4th embodiment. FIG. 15 is a cross-sectional view schematically showing a step following the step of FIG. 14; FIG. 16 is a cross-sectional view schematically showing a step following the step of FIG. 15; FIG. 17 is a cross-sectional view schematically showing a step following the step of FIG. 16; It is a sectional view showing typically one process in the 2nd process in another example of the manufacturing method of a 4th embodiment. FIG. 19 is a cross-sectional view schematically showing a step following the step of FIG. 18; FIG. 20 is a cross-sectional view schematically showing a step following the step of FIG. 19; FIG. 21 is a cross-sectional view schematically showing a step following the step of FIG. 20; FIG. 11 is a cross-sectional view schematically showing an example of an apparatus that can be used in the manufacturing method of the fourth embodiment; 23 is a photograph showing an example of the apparatus of FIG. 22; It is a sectional view showing typically one process in an example of a manufacturing method of a 5th embodiment. FIG. 25 is a cross-sectional view schematically showing a step following the step of FIG. 24; FIG. 26 is a cross-sectional view schematically showing a step following the step of FIG. 25; FIG. 27 is a cross-sectional view schematically showing a step following the step of FIG. 26; FIG. 28 is a cross-sectional view schematically showing a step following the step of FIG. 27; It is a sectional view showing typically one process in another example of the manufacturing method of a 5th embodiment. FIG. 30 is a cross-sectional view schematically showing a step following the step of FIG. 29; FIG. 30 is a cross-sectional view schematically showing a step following the step of FIG. 30; FIG. 32 is a cross-sectional view schematically showing a step following the step of FIG. 31; FIG. 33 is a cross-sectional view schematically showing a step following the step of FIG. 32; FIG. 4 is a perspective view schematically showing another example of the material steel plate according to the present invention; FIG. 35 is a cross-sectional view schematically showing the material steel plate shown in FIG. 34; FIG. 4 is a perspective view schematically showing another example of the material steel plate according to the present invention; FIG. 37 is a cross-sectional view schematically showing the material steel plate shown in FIG. 36; FIG. 4 is a cross-sectional view schematically showing the shape of a sample used in Experimental Example 2; FIG. 10 is a diagram schematically showing a three-point bending test simulated in Experimental Example 2; 7 is a graph showing the results of Experimental Example 2. FIG.

The present inventors have made intensive studies in order to obtain a molded product with high strength and excellent properties in a three-point bending test. It was found that a molded product with high strength and excellent characteristics in a three-point bending test can be obtained by producing it from a strong metal plate.
Specifically, it is formed from a high-strength metal plate, has two vertical wall portions and a top plate portion, and is provided with a projecting portion facing outward between the vertical wall portion and the top plate portion. It was found that a molded article having high strength and excellent properties in a three-point bending test was obtained.

However, in order to form a molded product having such a structure having protrusions from a high-strength metal plate, it was sometimes difficult to use cold press. Therefore, the present inventors attempted to manufacture the molded article having the above structure by hot stamp molding, in which press molding is performed while the metal plate, which is the material to be processed, is heated.

As a result, in order to obtain a molded product with high strength and excellent characteristics in the three-point bending test, it is necessary to perform a specific step of the manufacturing method of the molded product by hot stamping, so that it can be easily manufactured with good moldability. I found The present invention is based on this new finding.

Hereinafter, embodiments of the present invention will be described with examples.
In the following description, embodiments of the present invention will be described with examples, but it is obvious that the present invention is not limited to the examples described below. In the following description, specific numerical values and materials may be exemplified, but other numerical values and materials may be applied as long as the effects of the present invention can be obtained. In the following description, the molded product may be referred to as a "press molded product".

Further, in the following embodiments, the present invention will be described by taking as an example the case where the metal plate is a steel plate. A metal plate means a metal plate made of an aluminum-based alloy or a magnesium-based alloy, or containing these alloys. A steel plate in the following embodiments can be read as a metal plate.
The molded product according to the following embodiments is a long molded product made of steel and including a vertical wall portion, a projecting portion, and a top plate portion adjacent to the vertical wall portion via the projecting portion. .

The molded product according to the following embodiments includes, in the protruding portion, an overlapping portion where a portion of the steel plate extending from the top plate portion and a portion of the steel plate extending from the vertical wall portion overlap, and between the steel plates forming the overlapping portion. and a tip portion formed by bending a steel plate forming the overlapping portion.
Alternatively, the molded product according to the following embodiments includes, in the protruding portion, a superimposed portion where a part of the steel plate extending from the vertical wall portion or a part of the steel plate extending from the top plate portion overlaps, and a steel plate forming the superimposed portion. It has a sandwich portion sandwiched therebetween and a bent tip portion of the steel plate forming the overlapping portion.

In the molded product, at least the vertical wall portion, the top plate portion, and the overlapping portion forming the projecting portion are formed from steel plates.

In the projecting portion, a portion of the steel plate extending from the top plate portion and a portion of the steel plate extending from the vertical wall portion are overlapped with each other via the sandwiching portion. Alternatively, in the projecting portion, a part of the steel plate extending from the vertical wall portion overlaps with the sandwiching portion interposed therebetween, or a portion of the steel plate extending from the top plate portion overlaps with the sandwiching portion interposed therebetween.

Molded articles of the following embodiments have an elongated shape as a whole. The vertical wall portion, top plate portion, and projecting portion all extend along the longitudinal direction of the molded product. In addition, the molded article of the following embodiments may further have a flange portion extending from the vertical wall portion, and the flange portion and the projecting portion may be formed over the entire longitudinal direction of the molded product, It may be formed only partially in the longitudinal direction of the molded product.

Further, concave portions and convex portions may be formed in the vertical wall portion and the top plate portion. For example, the example of FIG. 10 shows an example in which a concave portion is formed in the top plate portion.

In the following description of the embodiments, the area surrounded by the two vertical wall portions, the imaginary plane connecting the ends of the two vertical wall portions, and the top plate portion will be referred to as “the inside of the molded product”. A region on the opposite side to the inside with the wall portion and the top plate portion sandwiched therebetween may be referred to as "the outside of the molded product".

In the molded product examples of the following embodiments, the top plate portion connects two vertical wall portions. More specifically, the top plate connects the two vertical walls via the projection. From another point of view, the top plate portion is a horizontal wall portion that connects two vertical wall portions. Therefore, in this specification, the top plate portion can be read as the lateral wall portion. When the molded product is arranged with the lateral wall portion (top plate portion) facing downward, the lateral wall portion can also be referred to as the bottom plate portion.

In the following embodiments, a portion of the projecting portion where the steel plates are double overlapped will be referred to as an "overlapping portion". The overlapped portion has a plate-like shape as a whole.
In the molded products of the following embodiments, the steel plate is bent at the tip of the projecting portion.

In the following embodiments, the "sandwiching part" may be composed of a member different from the steel plate forming the overlapping part. Alternatively, the “sandwiching portion” may be formed by a portion of the steel plate extending from the vertical wall portion or a portion of the steel plate extending from the top plate portion.
The sandwich is inserted between the steel plates forming the overlap.

When the sandwiching portion is composed of a member different from the steel plate forming the overlapping portion, a metal material, a ceramic material, or the like can be used as the sandwiching portion. From the viewpoint of ensuring the collision characteristics of the molded product, the material of the sandwiching portion is preferably a hard material, and more preferably a metal material.
Alternatively, from the viewpoint of ensuring the collision characteristics of the molded product while suppressing the manufacturing cost, it is preferable that the sandwiching portion is made of the same material as the top plate portion and the vertical plate portion.

The plate thickness ta of the sandwiched portion can be defined as the average thickness of the sandwiched portion sandwiched between the overlapping portions. Further, the plate thickness t of the steel plates forming the overlapping portion can be defined as the average thickness of the steel plates in the overlapping portion.

For example, if the sandwiching portion is a member different from the steel plate forming the overlapped portion, the average thickness of the member may be used as the plate thickness ta of the sandwiching portion.
When a portion of the steel plate extending from the vertical wall portion or a portion of the steel plate extending from the top plate portion forms the sandwiching portion, the average thickness of the steel plates forming the vertical wall portion or the top plate portion is the plate thickness t of the overlapping portion. may be Alternatively, the plate thickness t of the overlapping portion may be the average thickness of the portion forming the overlapping portion among the steel plates forming the vertical wall portion or the top plate portion.

In a cross-sectional view of a surface perpendicular to the longitudinal direction of the molded product, the "angle Y" formed by the top plate and the vertical wall is usually about 90°. The angle Y will be explained in the first embodiment. The angle Y may be less than 90°, but typically greater than or equal to 90°, and may be in the range of 90° to 150°. Although the two angles Y may be different, they are preferably substantially the same (the difference between them is within 10°), and may be the same.

In the following description of the embodiments, the angle formed by the top plate portion and the overlapping portion may be referred to as "angle X". In addition, if a part of the top plate is not flat due to the formation of minute unevenness on the top plate, the angle when the whole top plate is regarded as a flat plate is the angle of the top plate. .

In the molded articles of the following embodiments, the protrusions may protrude from each of the two borders. In this case, one projecting portion projects from each of the two boundary portions. The angle X between the two protrusions is preferably within 10°, and may be the same. The two protrusions are preferably formed such that their shapes in a cross section perpendicular to the longitudinal direction are symmetrical. However, the two projections do not have to be symmetrical.

In the molded products of the following embodiments, the angle X formed by the top plate portion and the projecting portion may be 90° or more, 105° or more, or 135° or more. good. The angle X may be 180° or less. In addition, the angle X of 180° means that the top plate portion and the projecting portion are parallel to each other. Angle X may be greater than 90° and less than or equal to 180°.

In the molded products of the following embodiments, the length of the protruding portion is the boundary where the extension lines of the vertical wall portion and the top plate portion intersect when viewed in cross section in a plane perpendicular to the longitudinal direction of the press-molded product. The length from the point to the outer wall surface of the tip of the protrusion may be 3 mm or more (eg, 5 mm or more, 10 mm or more, or 15 mm or more). Although the upper limit of the length is not particularly limited, it may be 25 mm or less, for example.
If the molded article includes two protrusions, the lengths of the two protrusions may be the same or different.

In the molded product of the following embodiments, a part of the overlapping part and a part of the sandwiching part may be fixed by a joining means in the projecting part. The joining means is, for example, welding or the like. For example, if the sandwiching portion is made of a steel plate, it may be welded by resistance spot welding or laser welding. Regardless of the material of the pinching portion, the joining means may be any one of welding, adhesive, brazing, riveting, bolting, and friction stir welding.

In the molded products of the following embodiments, the sandwiching portion and the overlapping portion may be in close contact with each other. Alternatively, there may be a space between the pinching portion and the overlapped portion for the portions that are not fixed by the joining means as described above.

When the above metal plate is a steel plate, TRIP steel, composite structure steel, steel plate for hot stamping, precipitation hardening steel, etc. can be used as the steel plate constituting the press-formed product of the following embodiments.
When the above-mentioned metal plate is a steel plate, the tensile strength of the steel plate constituting the molded article of the following embodiments may be 590 MPa or more, 780 MPa or more, or 980 MPa or more, Or it may be 1200 MPa or more. Although the upper limit of the tensile strength of the molded article is not particularly limited, it is, for example, 2500 MPa.

By performing the second step of the manufacturing method according to the embodiment described later by hot stamping, the tensile strength of the press-formed product can be made higher than the tensile strength of the steel plate (blank) that is the material.

In other words, when the tensile strength of the molded product is the above value or more, the martensite structure in the metal structure of the molded product is 20% or more in volume ratio, and the tensile strength of the molded product is 1310 MPa or more. When manufactured by hot stamping, the metal structure accounts for 90% or more.

In the molded products of the following embodiments, when the above-mentioned metal plate is a steel plate, for example, when the tensile strength of the molded product is 1500 MPa or more and the martensite structure is 90% or more in volume ratio, from the top plate part A portion of the extended steel plate, that is, the projecting portion may have a Vickers hardness of 454 or more. Moreover, the ratio of the Vickers hardness of the projecting portion to the Vickers hardness of the vertical wall portion at this time may be 0.95 or more.

The molded products of the following embodiments can be formed by deforming one material steel plate or a material steel plate in which a plurality of steel plates are joined. Specifically, a molded product can be manufactured by press-molding a material steel plate according to the manufacturing method of the following embodiment. The material steel plate used as the material will be described later.

(First embodiment)
A more specific example of the molded article according to the present invention will be described below as a first embodiment.
The molded product according to the present embodiment is a long molded product including a vertical wall portion formed of a steel plate, a projecting portion, and a top plate portion adjacent to the vertical wall portion via the projecting portion, In the projecting portion, an overlapping portion where a portion of the steel plate extending from the top plate portion overlaps a portion of the steel plate extending from the vertical wall portion, an sandwiching portion sandwiched between the steel plates forming the overlapping portion, and an overlapping portion. and a tip portion in which a steel plate forming the portion is bent.

A perspective view of a molded product 100 of the first embodiment is schematically shown in FIG. A cross-sectional view of a surface perpendicular to the longitudinal direction of the molded product 100 is schematically shown in FIG.
In the following, the upper side (top plate portion side) in FIG. 2 may be referred to as the upper side of the molded product of this embodiment, and the lower side (flange portion side) in FIG. 2 may be referred to as the lower side of the molded product of this embodiment. .

A molded product 100 is formed of one steel plate 101 . 1 and 2, elongated molded product 100 includes two vertical wall portions 111, a top plate portion 112, two flange portions 113, and two projecting portions 115. As shown in FIG.
Vertical wall portion 111, top plate portion 112, and flange portion 113 are each elongated and flat. The top plate portion 112 connects two vertical wall portions 111 adjacent to the top plate portion 112 via two projecting portions 115 .

In the example shown in FIG. 2 , the two flange portions 113 extend substantially horizontally outward from the lower ends of the two vertical wall portions 111 . That is, the flange portion 113 is substantially parallel to the top plate portion 112 .

The protruding portion 115 protrudes outward from a boundary portion 114 of a corner portion connecting the vertical wall portion 111 and the top plate portion 112 . An overlapping portion 115d exists at least on the tip portion 115t side of the projecting portion 115 .
In the overlapping portion 115d, the steel plate 101a extending from the top plate portion 112 (part of the steel plate extending from the top plate portion 112) and the steel plate 101b extending from the vertical wall portion 111 (part of the steel plate extending from the vertical wall portion 111) They are overlapped with sandwiching portions 116 interposed therebetween.

Steel plate 101a and steel plate 101b are parts of steel plate 101 respectively. A steel plate (steel plate 101a) extending from the top plate portion 112 is bent in the opposite direction at the tip portion 115t to form a steel plate 101b. The overlapping portion 115d has a flat plate shape as a whole.
A cross section (a cross section perpendicular to the longitudinal direction) of the molded product 100 excluding the protruding portion 115 is substantially hat-shaped.

As shown in FIG. 2, the angle formed by the top plate portion 112 and the projecting portion 115 is defined as an angle X. As shown in FIG. More specifically, the angle X includes a surface including the outer surface 112s of the top plate portion 112 and a surface 115ds of the overlapping portion 115d that is part of the projecting portion 115 (the surface of the steel plate 101a in the overlapping portion 115d). It refers to the angle formed by a plane.

1 and 2 show the case where the angle X is 180°. In this case, the top plate portion 112 and the projecting portion 115 are parallel. In a preferred example where the angle X is 180°, there is no step between the steel plate 101a extending from the top plate portion 112 and the top plate portion 112 .
From another point of view, the state in which the angle X is 180° can be regarded as a state in which the angle formed by the top plate portion 112 and the projecting portion 115 is 0°.

When the angle X is greater than 90°, when the molded product 100 is viewed from above the top plate portion 112, the steel plate 101b forming the projecting portion 115 is hidden by the steel plate 101a. Such portions are sometimes called negative corners. From another point of view, the negative corner portion is a portion having a reverse slope when press molding is performed using only the upper and lower dies.

When the molded product of this embodiment is used as a structural member, the top plate portion 112 and the flange portion 113 may be fixed to a part of another member. In that case, it may be preferred that the angle X is 180°.
When the angle X is 180° and the surface of the top plate portion 112 and the surface of the projecting portion 115 are flush with each other, it may be easier to fix the top plate portion 112 side to another member. Moreover, when a load is applied from the top plate portion 112 side, the load can be easily supported by the top plate portion 112 and the projecting portion 115 as a whole.

When the length of the projecting portion 115 and the surface perpendicular to the longitudinal direction of the molded product 100 are viewed in cross section, the vertical wall portion 111 and the top plate portion 112 each extend in a direction parallel to the length direction of the projecting portion 115. The length D (see FIG. 3) from the boundary point 114p at which the extensions of 114p to the tip 115t of the protrusion 115 may be within the range described above.

In the molded product of the present embodiment, as shown in FIG. 4, the vertical wall portion 111 and the steel plate 101b forming the projecting portion 115 are connected by the corner portion 117. As shown in FIG. Further, the top plate portion 112 and the steel plate 101a forming the projecting portion 115 are connected by a corner portion 117. As shown in FIG.

In the example of FIG. 3, since the angle X is 180°, there is no corner portion between the top plate portion 112 and the projecting portion 115 . In addition, when the corner portion 117 is not provided and the surface perpendicular to the longitudinal direction of the molded product 100 is viewed in cross section, the vertical wall portion 111 and the steel plate 101b, or the top plate portion 112 and the steel plate 101a have an angle. may be connected.

Further, as shown in FIG. 4, the steel plate bent in the opposite direction at the tip portion 115t has an inner wall surface 115ti.

The length _L0 of the overlapped portion 115d in the cross section perpendicular to the longitudinal direction of the molded product 100 is the steel plate 101b or the steel plate that constitutes the corner portion 117 and the protruding portion 115 in the direction parallel to the length direction of the protruding portion 115. 101a from the boundary point (not shown) to the inner wall surface 115ti of the steel plate bent at the tip portion 115t. In the absence of the corner portion 117, when the cross section of the surface perpendicular to the longitudinal direction of the molded product 100 is viewed, the connection point between the vertical wall portion 111 and the steel plate 101b or the connection point between the top plate portion 112 and the steel plate 101a to the inner wall surface 115ti is the length _L0 .

In the present embodiment, in the cross section perpendicular to the longitudinal direction of the molded product 100, the point of the inner wall surface 115ti farthest from the vertical wall portion 111 among the inner wall surfaces 115ti of the tip portion 115t is the distance L or length _L0 described later. standards. That is, the distance from this point to the predetermined position is defined as the distance L or the length _L0 .
The shape of the inner wall surface 115ti can take various forms, such as a semicircular shape, a semielliptical shape, and a triangular shape, in a cross section perpendicular to the longitudinal direction of the molded product 100 .

The length _L0 of the overlapped portion 115d is less than or equal to 1 times the length D of the protruding portion, and is in the range of 0.1 to 1 times (for example, 0.5 to 1 times, or 0.3 to 0.3 times). 8 times range).

In a region other than the tip portion 115t, a portion of the steel plate forming the projecting portion 115 may be curved, but is not bent. That is, except for the tip portion 115t, the protruding portion 115 does not have a ridge portion that protrudes outward from the protruding portion 115. As shown in FIG. In these respects, the molded product 100 is different from the parts described in Patent Documents 3 and 4.

FIG. 2 shows an example in which the angle Y formed by the vertical wall portion 111 and the top plate portion 112 is greater than 90°. Here, the angle Y is the angle shown in FIG. 2 , that is, the angle formed by the vertical wall portion 111 and the top plate portion 112 inside the molded product 100 .

As shown in FIG. 2, a corner portion 118 connecting the vertical wall portion 111 and the flange portion 113 may have a rounded shape. By having the rounded shape of corner portion 118 , buckling at corner portion 118 can be suppressed.

A corner portion 117 at the boundary between the steel plate 101b and the vertical wall portion 111 in the projecting portion 115 is preferably a curved surface when a surface perpendicular to the longitudinal direction of the molded product 100 is viewed in cross section. By forming the corner portion 117 into a curved surface, buckling at the corner portion 117 can be suppressed.

The radius of curvature of the corner portion 117 on the plane perpendicular to the longitudinal direction of the molded product 100 is in the range of 0.1 to 1 times the length D (for example, in the range of 0.2 to 0.8 times, or in the range of 0.2 to 0.2 times). .5 times range).
For example, when the angle X is smaller than 180°, the corner portion of the boundary between the steel plate 101a of the projecting portion 115 and the top plate portion 112 may be curved.

In the molded article according to this embodiment, the sandwiching portion 116 may extend along the vertical wall portion 111 or the top plate portion 112 .

FIG. 5 shows an example in which the sandwiching portion 116 extends along the vertical wall portion 111 . In this example, when the cross section of the surface perpendicular to the longitudinal direction of the molded product 100 is viewed, the sandwiching portion 116 extends along the corner portion 117 and the vertical wall portion 111 . Sandwiching portion 116 and vertical wall portion 111 or corner portion 117 may be joined by the above-described joining means.

Since the sandwiching portion 116 extends along the vertical wall portion 111, when an impact is applied from a direction substantially perpendicular to the plate surface of the top plate portion 112, the vertical wall portion 111 moves toward the inside of the molded product 100. It is possible to suppress deformation and further improve collision safety performance when used as a structural member of an automobile.

FIG. 6 shows an example in which the sandwiching portion 116 extends along the top plate portion 112 . In this example, when the cross section of the surface perpendicular to the longitudinal direction of the molded product 100 is viewed, the sandwiching portion 116 extends along the top plate portion 112 . The sandwiching portion 116 and the top plate portion 112 may be joined by the joining means described above. In the example of FIG. 6, the sandwiching portion is flat.
Since the sandwiching portion 116 extends along the top plate portion 112, it is possible to increase the rigidity of the surface parallel to the plate surface of the top plate portion 112, thereby improving the collision safety performance when used as a structural member of an automobile. can be improved.

In the molded product according to this embodiment, the sandwiching portion 116 may be provided over the entire length of the molded product 100 in the longitudinal direction, or may be provided only in a part of the molded product 100 in the longitudinal direction.

For example, the sandwiching portion 116 may be provided only at the central position in the longitudinal direction of the molded product 100 , or the sandwiching portion 116 may be provided only near both ends in the longitudinal direction of the molded product 100 .

Also, in the longitudinal direction of the molded product 100, a plurality of sandwiching portions 116 may be arranged in a line with a predetermined interval. In this case, the length of the sandwiching portion 116 in the longitudinal direction of the molded product 100 and the spacing between the sandwiching portions 116 are not particularly limited, but the moldability may not be deteriorated even in a place where the sandwiching portion 116 is not present.

(Second embodiment)
A second embodiment of the molded article according to the present invention will be described below.
The molded product according to the present embodiment is a long molded product that is formed of a steel plate and includes a vertical wall portion, a projecting portion, and a top plate portion adjacent to the vertical wall portion via the projecting portion. , in the protruding portion, a superposed portion where a part of the steel plates extending from the top plate portion overlap, an sandwiching portion sandwiched between the steel plates forming the superposed portion, and a tip where the steel plates forming the superposed portion are bent a portion of the steel plate extending from the top plate portion forming the overlapping portion, and a portion of the steel plate extending from the vertical wall portion forming the sandwiching portion.

A molded product 200 according to this embodiment has the same basic configuration as that of the first embodiment, except for the configurations of an overlapping portion 215d and a sandwiching portion 216, which will be described below.

FIG. 7 schematically shows a cross-sectional view of a surface perpendicular to the longitudinal direction of the molded product 100 of the second embodiment. FIG. 7 shows a cross-sectional view of the protruding portion 215 and its surroundings.

The molded product 200 includes a steel plate 201 forming a top plate portion 212 and a steel plate 202 forming a vertical wall portion 211 . As shown in FIG. 7 , the molded product 200 includes a vertical wall portion 211 , a top plate portion 212 , a flange portion 213 and a projecting portion 215 .
The vertical wall portion 211, the top plate portion 212, and the flange portion 213 are each elongated and flat. The top plate portion 212 connects two vertical wall portions 211 adjacent to the top plate portion 212 via two projecting portions 215 .

The protruding portion 215 protrudes outward from the boundary portion of the corner portion connecting the vertical wall portion 211 and the top plate portion 212 . An overlapping portion 215d exists at least on the tip portion 215t side of the projecting portion 215 .
In the overlapping portion 215 d , the steel plate 201 extending from the top plate portion 212 (part of the steel plate extending from the top plate portion 212 ) is arranged with the steel plate 202 extending from the vertical wall portion 211 sandwiched therebetween. are superimposed on each other.

Steel plate 201 extending from top plate portion 212 is bent in the opposite direction at tip portion 215t. The overlapping portion 215d has a flat plate shape as a whole.
A cross section (perpendicular to the longitudinal direction) of the molded product 200 excluding the protruding portion 215 is substantially hat-shaped.

FIG. 7 shows the case where the angle formed by the top plate portion 212 and the projecting portion 215 is 180°. In this case, the top plate portion 212 and the projecting portion 215 are parallel.

In the molded product 200 of the present embodiment, as shown in FIG. 7, the vertical wall portion 211 and the sandwiching portion 216 are connected by the corner portion 217 . That is, the steel plate 202 forming the vertical wall portion 211 is bent at the corner portion 217 .
In the example of FIG. 7 , since the angle formed by the top plate portion 212 and the projecting portion 215 is 180°, there is no corner portion between the top plate portion 212 and the projecting portion 215 . Further, when the corner portion 217 is not provided and the surface perpendicular to the longitudinal direction of the molded product 200 is viewed in cross section, the vertical wall portion 211 or the top plate portion 212 and the protruding portion 215 are connected with an angle. may

Further, as shown in FIG. 7, the steel plate 201 forming the top plate portion 212 is bent in the opposite direction at the tip portion 215t to form an inner wall surface 215ti.

The length _L0 of the overlapped portion 215d in the cross section perpendicular to the longitudinal direction of the molded product 200 is the steel plate 201 or the steel plate forming the corner portion 217 and the protrusion 215 in the direction parallel to the length direction of the protrusion 215. 202 to the inner wall surface 215ti of the steel plate 201 bent at the tip portion 215t. If there is no corner portion 217, when the cross section of the surface perpendicular to the longitudinal direction of the molded product 200 is viewed, the connection point between the vertical wall portion 211 and the sandwiching portion 216, or the top plate portion 212 and the overlapping portion 215d. , to the inner wall surface 215ti is the length _L0 .

(Third embodiment)
A third embodiment of the molded article according to the present invention will be described below.
The molded product according to the present embodiment is a long molded product that is formed of a steel plate and includes a vertical wall portion, a projecting portion, and a top plate portion adjacent to the vertical wall portion via the projecting portion. , in the protruding portion, a superposed portion where a part of the steel plates extending from the vertical wall portion overlap, an sandwiching portion sandwiched between the steel plates forming the superposed portion, and a tip where the steel plates forming the superposed portion are bent a portion of the steel plate extending from the vertical wall portion forms the overlapping portion, and a portion of the steel plate extending from the top plate portion forms the pinching portion.

A molded product 300 according to this embodiment has the same basic configuration as that of the first embodiment or the second embodiment, except for the configurations of an overlapping portion 315d and a sandwiching portion 316, which will be described below. omitted.

FIG. 8 schematically shows a cross-sectional view of a surface perpendicular to the longitudinal direction of the molded product 300 of the third embodiment. FIG. 8 shows a cross-sectional view of the protruding portion 315 and its surroundings.

A molded product 300 includes a steel plate 301 forming a top plate portion 312 and a steel plate 302 forming a vertical wall portion 311 . As shown in FIG. 8 , the molded product 300 includes a vertical wall portion 311 , a top plate portion 312 , a flange portion 313 and a projecting portion 315 .
The vertical wall portion 311, the top plate portion 312, and the flange portion 313 are each elongated and flat. The top plate portion 312 connects two vertical wall portions 311 adjacent to the top plate portion 312 via two projecting portions 315 .

The protruding portion 315 protrudes outward from the boundary portion of the corner portion connecting the vertical wall portion 311 and the top plate portion 312 . An overlapping portion 315d exists at least on the tip portion 315t side of the projecting portion 315 .
In the overlapping portion 315 d , the steel plate 302 extending from the vertical wall portion 311 (part of the steel plate extending from the vertical wall portion 311 ) is arranged to sandwich the steel plate 301 extending from the top plate portion 312 , thereby are superimposed on each other.

Steel plate 302 extending from vertical wall portion 311 is bent in the opposite direction at tip portion 315t. The overlapping portion 315d has a flat plate shape as a whole.
A cross section of the molded product 300 excluding the protrusion 315 (a cross section perpendicular to the longitudinal direction) is substantially hat-shaped.

FIG. 8 shows a case where the angle formed by the top plate portion 312 and the projecting portion 315 is 180°. In this case, the top plate portion 312 and the projecting portion 315 are parallel.

In the molded product 300 of this embodiment, the vertical wall portion 311 and the overlapping portion 315d are connected by the corner portion 317, as shown in FIG. That is, the steel plate 302 forming the vertical wall portion 311 is bent at the corner portion 317 .
In the example of FIG. 8, since the angle formed by the top plate portion 312 and the projecting portion 315 is 180°, a corner is formed between the top plate portion 312 and the projecting portion 315 (or the top plate portion 312 and the sandwiching portion 316). part does not exist. Further, when the corner portion 317 is not provided and the surface perpendicular to the longitudinal direction of the molded product 300 is viewed in cross section, the vertical wall portion 311 or the top plate portion 312 and the protruding portion 315 are connected at an angle. may

Further, as shown in FIG. 8, the steel plate 302 forming the vertical wall portion 311 is bent in the opposite direction at the tip portion 315t to form an inner wall surface 315ti.

The length _L0 of the overlapped portion 315d in the cross section perpendicular to the longitudinal direction of the molded product 300 is the steel plate 301 or the steel plate that constitutes the corner portion 317 and the protruding portion 315 in the direction parallel to the length direction of the protruding portion 315. 302 to the inner wall surface 315ti of the steel plate 301 bent at the tip 315t. In the absence of the corner portion 317, when the cross section of the surface perpendicular to the longitudinal direction of the molded product 300 is viewed, the connecting point between the vertical wall portion 311 and the overlapping portion 315d, or the top plate portion 312 and the sandwiching portion 316 , to the inner wall surface 315ti is the length _L0 .

In the molded products according to the second and third embodiments, the steel plate forming the vertical wall portion and the steel plate forming the top plate portion are made of different steel plates. Therefore, by making the thickness of the steel plate that forms the vertical wall part, which contributes to the collision resistance of the molded product, thicker than the plate thickness of the steel plate that forms the top plate part, it is possible to reduce the weight of the member while ensuring collision resistance. can be planned.

In the molded product of the above-described embodiment, a part of the overlapping part and a part of the sandwiching part may be joined by welding. As a result, the rigidity of the projecting portion can be increased, and the collision safety performance when used as a structural member of an automobile can be further improved.

For example, in the first embodiment described above, the steel plate 101a extending from the top plate portion 112 and the sandwiching portion 116 may be joined by welding. Alternatively, the steel plate 101b extending from the vertical wall portion 111 and the sandwiching portion 116 may be joined by welding. Note that the above-described joining means can be employed.

The molded product of the above-described embodiment may have a projecting region having a projecting portion and a non-projecting region having no projecting portion in the longitudinal direction of the molded product.

9 and 10 schematically show a perspective view of an example of a molded article in which protrusions are formed only partially in the longitudinal direction. In the molded article 400 (or molded article 500) of FIG. 9 or 10, the protrusions 415 (or protrusions 515) are not formed in the regions P2 at both ends in the longitudinal direction, and protrude in the central region P1 in the longitudinal direction. A portion 415 (or a protruding portion 515) is formed.

With this configuration, when the press-formed product is combined with other members to form a structural member, the other members are not subject to shape restrictions, and desired collision safety performance can be obtained.

The length of region P1 in the longitudinal direction of molded product 400 (or molded product 500) may be 30% or more of the total longitudinal length of molded product 400 (or molded product 500).

In the region P1 where the protruding portion 415 (or protruding portion 515) is formed, the sandwiching portion 416 (or sandwiching portion 516) may be provided over the entire length in the longitudinal direction. , a plurality of sandwiching portions 416 (or sandwiching portions 516) may be arranged in a row at predetermined intervals.

In the molded product of the above embodiment, the ultimate deformability of the steel plate forming the overlapping portion is |εt|, the thickness of the steel plate forming the overlapping portion is t, and the thickness of the sandwiching portion is ta. The uniform elongation of the steel sheets forming the lapped portion may be more than 5% while satisfying (Equation 1).

|εt|>ln((2t+ta)/(t+ta)) . . . (Formula 1)

The "ultimate deformability |εt|" of a steel sheet can be defined as the ultimate deformability in plane strain tension. Specifically, a plate having _a thickness of _t0 is subjected to tensile deformation, and the plate thickness at the fracture site when the plate is fractured in a plane strain state, assuming that there is no contraction in the width direction of the plate, is set to t1. Then, the ultimate deformability |εt| can be expressed by the following (Equation A).
A grooved tensile test, the Nakajima method, and the Marciniak method can be adopted as methods for breaking a plate in a plane strain state.

|εt|=ln(t ₁ /t ₀ ) . . . (Formula A)

The "uniform elongation" of a steel plate means the limit value of permanent elongation at which the parallel portion of a test piece deforms almost uniformly in a tensile test. Specifically, it can be defined as uniform elongation obtained by a tensile test specified in JIS Z 2241 (2011).

In the molded product of the above-described embodiment, when the distance from the inner wall surface of the tip portion where the steel plate forming the overlapping portion is bent to the pinching portion is L, and the plate thickness of the pinching portion is ta, the following (Equation 2 ) may be configured to satisfy
0≦L≦5 ta. . . (Formula 2)

In the above-described embodiment, L is defined as the distance from the inner wall surface of the steel plate forming the tip portion to the sandwiching portion.
The distance L satisfies L≦5ta. That is, the distance L is defined within five times the plate thickness ta of the sandwiching portion. Also, the distance L satisfies L≧0.
Alternatively, the distance L may be less than or equal to _L0 if the above (Equation 1) is satisfied.

The end portion of the sandwiching portion is shaped so that the cross section perpendicular to the longitudinal direction of the molded product can take various forms such as a semicircular shape, a semielliptical shape, and a triangular shape. can be 0.

The molded articles of the embodiments described above can be used in a variety of applications. For example, it can be used for structural members of various means of transportation (automobiles, two-wheeled vehicles, railway vehicles, ships, aircraft) and structural members of various machines.

Examples of automotive structural members include side sills, pillars (front pillars, front pillar lowers, center pillars, etc.), roof rails, roof arches, bumpers, beltline reinforcements, and door impact beams, and other structures. It may be a member.

The molded products according to the above embodiments can be used as they are as various structural members. Alternatively, the molded article according to the above-described embodiments may be used in combination with other members (for example, steel plate members).

Here, the steel plate member is a member formed of a steel plate. Structural members described in the following embodiments include the press-formed products of the embodiments described above. In addition, the structural members for automobiles described below can be used as structural members for products other than automobiles.

An example of the structural member includes a structural member configured to include the molded article of the above-described embodiment and a steel plate member fixed to the molded article and the molded article so as to form a closed cross section. That is, the molded product and the steel plate member may form a hollow body.

It may include the molded product of the embodiment described above and one steel plate member fixed to two flange portions of the molded product. In other words, the steel plate member may be fixed to the two flange portions of the molded product so as to connect the two flange portions.

Another member may be further fixed to the flange portion. An example of the steel plate member is the press-formed product of the embodiment described above. In one example of such a case, two press-formed products that are fixed to each other are fixed so that their inner sides face each other. Examples of the steel plate member may include a steel plate (back plate) and a molded product other than the molded product of the above-described embodiments.

If the molded product does not include a flange portion, the steel plate member may be fixed to the vertical wall portion of the molded product so as to form a closed cross-section. For example, a flange portion may be provided at the end of the steel plate member, and the flange portion and the vertical wall portion of the molded product may be fixed.

That is, when the molded product according to the above embodiment and the steel plate member fixed to the molded product are included, and the cross section of the surface perpendicular to the longitudinal direction of the molded product is viewed, the molded product and the steel plate member form a closed cross section. It is good also as a structural member which carries out.

There is no particular limitation on the method of fixing the molded product and the steel plate member, and an appropriate fixing method may be selected depending on the situation. Examples of fixing methods include at least one selected from the group consisting of welding, adhesives, brazing, riveting, bolting, and friction stir welding. Among these, welding is easy to implement. Examples of welding include resistance spot welding and laser welding.

Also, only a part of the flange portion of the molded product of the embodiment described above may be fixed to another steel plate member. In that case, other parts of the flange portion are not fixed to other steel plate members. For example, of the flange portions of the molded product of the above-described embodiment, only the flange portions near both ends in the longitudinal direction are fixed to other steel plate members, and the other flange portions are not fixed to other steel plate members. good.

Further, in the structural member, at least one of the two vertical wall portions and the top plate portion, or at least one of the two vertical wall portions and the top plate portion is joined to each It may further include an auxiliary member.

In the molded product according to the embodiment described above, the projecting portion is provided with the overlapping portion and the pinching portion, so that the bending deformation resistance of the projecting portion increases when an impact is received, and the impact characteristics are improved. becomes possible.

A method for manufacturing a molded product according to the present invention will be described below. A method for manufacturing a molded article according to the present invention is a method for manufacturing the molded article of the embodiment described above.
Since the matters described for the molded product of the embodiment described above can be applied to the manufacturing method described below, redundant description may be omitted. Also, it is obvious that the matters described in the following manufacturing method can be applied to the molded articles of the above-described embodiments.

The manufacturing method of the following embodiments includes a first step and a second step.
In the first step, two vertical wall portions corresponding to the two vertical wall portions, a top plate portion corresponding to the top plate portion, a projection portion corresponding to the protrusion, and a sandwiching portion corresponding to the sandwiching portion It is a step of obtaining a deformed steel plate (deformed steel plate) in which the two vertical wall portion corresponding parts are bent in the same direction with respect to the top plate corresponding part by deforming the material steel plate containing.
The second step is a step of forming a press-formed product by hot-press-forming the deformed steel plate. In the second step, the protrusion is formed by overlapping at least a part of the portion corresponding to the protrusion with sandwiching the portion corresponding to the sandwiching portion to be the sandwiching portion.

In the deformed steel plate, there is usually no clear boundary between the portion corresponding to the vertical wall portion, the portion corresponding to the top plate portion, the portion corresponding to the sandwiching portion, and the portion corresponding to the protrusion portion. However, there may be some boundaries between them.

The deformed steel plate may be in an elastically deformed state in which the deformation is canceled when the load is removed, or may be in a plastically deformed state in which the deformation is not canceled even when the load is removed. That is, the deformed steel plate may be in a state of plastic deformation or in a state of elastic deformation. A deformed steel sheet in a plastically deformed state may hereinafter be referred to as a "preform".

The first step is not particularly limited, and may be performed by known press molding.

Although the second step will be described later, hot press molding is used in the second step. The press-formed product obtained by the second step may be further post-treated.
The molded article obtained by the second step (or obtained by subsequent post-treatment) may be used as it is or may be used in combination with other members.

Below, the steel plate (material steel plate) which is a starting material may be called a "blank." The blank is generally a flat steel plate and has a planar shape corresponding to the shape of the press-formed product to be produced.

The thickness and physical properties of the blank are selected according to the properties required for the press-molded product.
For example, if the press-formed product is a structural member for an automobile, the blank is selected accordingly. The thickness of the blank may, for example, be in the range 0.4 mm to 4.0 mm, or in the range 0.8 mm to 2.0 mm. The thickness of the molded article of the above-described embodiment is determined by the thickness of the blank and the processing process, and may be within the thickness range of the blank exemplified here.

The blank has a portion corresponding to the sandwiching portion that serves as the sandwiching portion.
Also, the blank may have a tip-corresponding portion that serves as the tip. The portion corresponding to the tip may be included in the portion corresponding to the protrusion.

The blank is preferably a high-tensile steel plate (high-tensile material) having a tensile strength of 340 MPa or higher (for example, a tensile strength of 500-800 MPa, 490 MPa or higher, 590 MPa or higher, 780 MPa or higher, 980 MPa or higher, or 1200 MPa or higher).

In order to reduce the weight while maintaining the strength as a structural member, it is preferable that the tensile strength of the molded product is high, and it is more preferable to use a blank of 590 MPa or more (for example, 780 MPa or more, 980 MPa or more, or 1180 MPa or more). preferable.
There is no upper limit to the tensile strength of the blank, and one example is 2500 MPa or less. The tensile strength of the press-molded product of this embodiment is usually equal to or higher than the tensile strength of the blank, and may be within the range exemplified here.

When the tensile strength of the material steel plate (blank) is 590 MPa or more, the second step should be performed by hot press forming (also referred to as hot stamping or hot pressing) in order to obtain a press-formed product equal to or greater than the blank. is important.
Even if blanks with a tensile strength of less than 590 MPa are used, the second step may be performed by hot stamping. If hot stamping is to be carried out, blanks of known composition suitable for that purpose may be used.

In the conventional manufacturing method, if the tensile strength of the blank is high, there is a risk that cracks will occur at the tip of the protrusion in the cold press. Since it has a portion corresponding to the sandwiching portion, it is possible to suppress the occurrence of wrinkles and cracks due to protrusions and the like even when a blank having high tensile strength is used.

For example, when the tensile strength of the steel sheet after forming is 1200 MPa or more (for example, 1500 MPa or more or 1800 MPa or more), the second step is performed by hot stamping to produce a molded product with good formability. can be done.
Even if the tensile strength of the steel sheet after forming is less than 1200 MPa, by performing the second step by hot stamping, it is possible to easily produce a formed product with good formability.

Patent Documents 3 and 4 do not disclose a manufacturing method using hot stamping. However, as described above, in order to obtain a press-formed product having a tensile strength of 590 MPa or more, it is more preferable to perform the second step by hot stamping.

In hot press molding, the chemical composition of the blank more preferably has a C content of 0.09 to 0.40% by mass in order to ensure the desired strength. Moreover, it is more preferable to have 1.0 to 5.0% by mass of Mn as well. Also, it is more preferable to have 0.0005 to 0.0500% by mass of B as well.

In addition, the typical chemical composition of the blank with a tensile strength of 1500 MPa or more after quenching is not particularly limited, but C: 0.19 to 0.23 mass%, Si: 0.18 to 0.22 mass%, Mn: 1.1 to 1.5% by mass, Al: 0.02 to 0.04% by mass, Ti: 0.015 to 0.030% by mass, B: 0.0010 to 0.0020% by mass is preferable, for example, C: 0.20 mass%, Si: 0.20 mass%, Mn: 1.3 mass%, Al: 0.03 mass%, Ti: 0.020 mass%, B: 0.0015 % by mass.

The deformation in the first step is usually not too great. Therefore, regardless of the tensile strength of the blank, the first step can usually be performed by cold working (eg cold pressing). However, if necessary, the first step may be performed by hot working (for example, hot pressing).

A case where hot stamping is performed in the second step will be described.
First, the workpiece (blank or preform) is heated to a predetermined hardening temperature. The quenching temperature is a temperature higher than the A3 transformation point (more specifically, the Ac3 transformation point) at which the workpiece austenites, and may be 910° C. or higher, for example.

Next, the heated workpiece is pressed by a pressing device. Since the workpiece is heated, cracks are less likely to occur even if it is deformed significantly. Rapidly cool the workpiece when pressing the workpiece. Due to this rapid cooling, the workpiece is quenched during press working.
Rapid cooling of the workpiece can be carried out by cooling the mold or jetting water from the mold toward the workpiece. The cooling rate when quenching the workpiece by the pressing device is preferably 30° C./s or more, for example.

The hot stamping procedure (heating, pressing, etc.) and the equipment used therefor are not particularly limited, and known procedures and equipment may be used.

The preform may include a U-shaped portion having a U-shaped cross-section perpendicular to the longitudinal direction. This U-shaped part becomes two vertical wall parts, a top plate part, and a projecting part. The end of the U-shaped portion may be connected to a portion to be the flange portion.

In the following description, the term "section" basically means a section perpendicular to the longitudinal direction of a member such as a preform.

[Manufacturing method by two steps]
An example of a method for manufacturing a molded product (two-step manufacturing method for a molded product) including the first step and the second step described above and performing these steps using different apparatuses or molds will be described below.

In the second step, press molding is performed by a press die including an upper die and a lower die and two cam dies.
In the second step, (a) a step of pressing the portion corresponding to the top plate portion with an upper die and a lower die, and (b) a step of pressing two portions corresponding to the vertical wall portion with a lower die and two cam dies. and including.

In the manufacturing method of the fifth embodiment described below, the second step may include the following steps (a) and (b). This second step is preferably used when the deformed steel plate is a plastically deformed preform.

In step (a), the portion corresponding to the top plate portion is pressed by a press die including a pair of upper and lower dies. In step (b), the two vertical wall portions are pressed by a lower die and two cam dies.

In the manufacturing method of the embodiment described below, a mold may be used in which the protruding portion is formed when both step (a) and step (b) are completed. The cam die mainly moves in a direction (horizontal direction) perpendicular to the pressing direction. In one typical example, the cam mold moves only horizontally.

The timing of performing step (a) and step (b) can be selected depending on the situation, and either one may be completed first, or both may be completed at the same time. Either step (a) or step (b) may be started first, or both may be started simultaneously.
First to third examples in which the timing of completion of step (a) and step (b) are different will be described below.

In a first example of the second step, step (b) is completed after step (a) is completed. The first example is preferably performed when the angle X formed by the top plate portion and the overlapping portion is greater than 90° and less than or equal to 135°.
The movement of the cam die in step (b) may be started before step (a) is completed, as long as step (b) is completed after step (a) is completed.

In a second example of the second step, step (a) is completed after step (b) is completed. The second example is preferably performed when the angle X formed by the top plate portion and the overlapping portion is 135° or more (for example, in the range of 135° to 180°).
As long as the step (a) is completed after the step (b) is completed, the movement of the press die in the step (a) may be started before the step (b) is completed.

In a third example of the second step, steps (a) and (b) are completed simultaneously. As long as steps (a) and (b) are completed at the same time, there is no limitation on the timing of starting movement of the press die in step (a) and the timing of starting movement of the cam die in step (b).

Note that when the second step is performed by hot press molding, a step of heating the deformed steel plate is further provided between the first step and the second step, and in the second step, the convex portion of the lower mold and the deformation It further has a step of arranging in a state where the steel plate is not in contact with the steel plate.

(Fourth embodiment)
In a fourth embodiment, a method for manufacturing molded articles is described. 4th Embodiment demonstrates an example which manufactures the press-formed product demonstrated in 1st Embodiment.

In the method for manufacturing a molded product according to the fourth embodiment, in the method for manufacturing a molded product according to the above-described embodiments, the elongated shape is formed by deforming the material steel plate having the portion corresponding to the sandwiching portion to be the sandwiching portion. a first step of obtaining a deformed steel plate having a portion corresponding to the sandwiching portion, a portion corresponding to the vertical wall portion serving as the vertical wall portion, a portion corresponding to the top plate portion serving as the top plate portion, and a portion corresponding to the protrusion portion serving as the protrusion; and a second step of further hot-press-molding the deformed steel sheet to form a molded product, wherein in the second step, the portions corresponding to the protrusions are overlapped, and the portions corresponding to the sandwiching portions are sandwiched by the portions corresponding to the protrusions, thereby protruding. form a part.

In the fourth embodiment, a case where a preform that is plastically deformed is used as a deformed steel plate will be described.

FIG. 11 shows an example of the material steel plate. In the example of FIG. 11 , the material steel plate 600 has one steel plate 601 and a pinching portion corresponding portion 602 joined to the steel plate 601 .

12 is a cross-sectional view of the material steel plate 600 of FIG. 11, and is a cross-sectional view of the material steel plate 600 when viewed from a direction parallel to the longitudinal direction of the material steel plate 600 of FIG.
As shown in FIG. 12, the material steel plate 600 has a portion 602 corresponding to a sandwiching portion, a portion 603 corresponding to a vertical wall portion, a portion 604 corresponding to a top plate portion, and a portion 605 corresponding to a projection portion.

First, in the first step, the portions to be two vertical wall portions 111 (two vertical wall portion corresponding portions 603), the portion to be the top plate portion 112 (top plate portion corresponding portion 604), and the two sandwiching portions 116 are formed. A pre-formed product 610 (deformed steel plate) including at least portions (two sandwiching portion corresponding portions 602 ) and a portion that will become the projecting portion 115 (projecting portion corresponding portion 605 ) is formed by deforming the material steel plate 600 .

A 1st process can be performed by the method (for example, press work) mentioned above. A cross section (perpendicular to the longitudinal direction) of an example of the preform 610 formed in the first step is schematically shown in FIG.

As shown in FIG. 13 , the preform 610 includes a U-shaped portion 611 a and a flat portion 611 b (portion corresponding to the flange portion) that becomes the flange portion 113 . The U-shaped portion 611 a includes two vertical wall portion corresponding portions 603 and a top plate portion corresponding portion 604 , and further includes a projecting portion corresponding portion 605 .
In the preform 610 , the two vertical wall portion corresponding portions 603 are bent in the same direction with respect to the top plate portion corresponding portion 604 . That is, both of the two vertical wall portion corresponding portions 603 are bent toward one main surface side of the top plate portion corresponding portion 604 .

The cross-section of the preform 610 is generally hat-shaped. Also, the cross section of the U-shaped portion 611a is substantially U-shaped. The preform 610 is plastically deformed and retains the shape of FIG. 13 in the unloaded state.

Let Lu be the length (cross-sectional length) of the U-shaped portion 611a. Further, in the molded product, the height of the vertical wall portion is Hb, and the width between the two vertical wall portions is Wb. The U-shaped portion 611a includes, in addition to the vertical wall portion corresponding portion 603 and the top plate portion corresponding portion 604, a projecting portion corresponding portion 605 that becomes the projecting portion 115 in the second step. Therefore, length Lu, width Wb, and height Hb satisfy the relationship Wb+2Hb<Lu.

Further, the width of the U-shaped portion 611a is Wa and the height is Ha. Normally, the relationship Wb≦Wa and the relationship Wb+2Hb<Wa+2Ha are satisfied.
In addition, in the U-shaped portion 611a of the preform 610 shown in FIG. 13, there is no clear boundary between the protrusion-corresponding portion 605 and other portions.

The end portion of the flat portion 611b of the preform 610 may be lowered downward (in the direction away from the top plate portion 112). 14 to 17 below, an example of performing the second step using a preform 610 in which the end of the flat portion 611b is not lowered will be described.
As shown in FIGS. 18 to 21, a preform 610 having flat portions 611b with lowered ends can also be formed in the same manner.

The second step is done by hot stamping. Therefore, the preform is heated in advance to a temperature equal to or higher than the Ac3 transformation point (for example, a temperature higher than the Ac3 transformation point by 80° C. or more). This heating is performed, for example, by heating the preform in a heating device.

Next, the preform 610 is pressed by the pressing device 40a. An example of the configuration of a press die used for press working is shown in FIG. 14 and the like. The press device 40 a includes a press die 10 , a plate 13 , an extension mechanism 14 , a cam pressing die 15 and a cam die (slide die) 21 .

The press die 10 includes a pair of upper die 11 and lower die 12 . The lower mold 12 includes a convex portion 12 a whose convex surface faces the upper mold 11 .
Cam pressing die 15 and cam die 21 respectively have inclined surfaces 15a and 21a that act as cam mechanisms. The cam pressing die 15 is fixed to the plate 13 via an extendable extension mechanism 14 . A known elastic mechanism such as a spring and a hydraulic cylinder can be used for the elastic mechanism.

As the plate 13 descends, the upper die 11 and the cam pressing die 15 descend. As the cam pressing die 15 descends, the cam die 21 is pushed by the cam pressing die 15 and moves toward the convex portion 12 a of the lower die 12 .
As is well known, the timing of movement of cam die 21 can be adjusted by changing the position and shape of inclined surfaces 15a and 21a. That is, by adjusting them, the timing of completion of step (a) and step (b) can be adjusted.

In the above example, the cam die 21 is moved by the cam mechanism. However, instead of using the cam mechanism, the cam die 21 may be moved independently by a hydraulic cylinder or the like without depending on the movement of other dies.

This embodiment illustrates an example in which the upper die 11 and the cam pressing die 15 are attached to the same slide of the press via the plate 13 . However, the upper die 11 and the cam pressing die 15 may be mounted on separate slides of the press and operated separately.

In addition, in this embodiment, an example is illustrated in which the cam pressing die 15 is pressed to move the cam die 21 . However, cam die 21 may be moved independently by a drive directly attached to cam die 21 .

The press die 10 and cam die 21 have a cooling function. For example, when hot stamp molding is employed, the press die 10 and the cam die 21 may be configured such that cooling water circulates inside them. The heated preform 610 is shaped and cooled by pressing with a cooled mold. As a result, press forming and quenching are performed simultaneously.
In addition, you may cool by jetting water from a metal mold|die.

An example of the press molding process using the apparatus of FIG. 14 will be described.
14 to 17 schematically show an example of performing the second step in the method of the second example described above. This second example method is preferably used when the angle X is in the range of 135° to 180°.

First, as shown in FIG. 14, a preform 610 is arranged between the upper mold 11 and the lower mold 12 .
At this time, it is important to dispose the protruding portion 12a of the lower mold 12 and the preform 610 in a state that they are not in contact with each other.

Since the second step is performed by hot stamping, when the preform 610 is placed between the upper mold 11 and the lower mold 12, the U-shaped portion 611a of the deformed steel plate 610 (the portion corresponding to the pinching portion 602, the vertical wall region corresponding to part 603, part corresponding to top plate part 604, and part corresponding to projecting part 605) is in contact with projecting part 12a of lower die 12, deformed steel plate 610 is in contact with projecting part 12a of lower die 12. The contact portion is cooled by the lower die 12 .
In this case, the steel sheet temperature required for hot pressing cannot be maintained during press forming. As a result, the press-molded product may crack or wrinkle, making it impossible to obtain the desired strength. Also, the cooling rate required for quenching could not be obtained. Desired strength cannot be obtained.

In particular, the portion of the deformed steel plate 610 that becomes the protruding portion 115 (the protruding portion corresponding portion 605) and its vicinity are prone to cracks and wrinkles. Placement is important.

Next, the plate 13 is lowered. The cam die 21 is pushed by the cam pressing die 15 descending with the plate 13 and slides toward the convex portion 12a.
As a result, as shown in FIG. 15, the lower die 12 (the convex portion 12a) and the cam die 21 press the vertical wall portion 111 to constrain it. Thus, step (b) is completed.

Next, as shown in FIG. 16, the plate 13 is further lowered to start pressing the portion that will become the top plate portion 112 . At this time, the expansion mechanism 14 contracts.

Since the preform 610 has a projection-corresponding portion 605, the projection-corresponding portion 605 protrudes toward the cam die 21 side.

Next, as shown in FIG. 17, the upper die 11 is lowered to the bottom dead center, and the portion that will become the top plate portion 112 is pressed and constrained by the upper die 11 and the lower die 12 (projections 12a). Thus, step (a) is completed.

Press molding is completed as described above. The projection-corresponding portion 605 is folded between the upper mold 11 and the cam mold 21 to form the projection 115 having the overlapping portion 115d. A sandwiching portion 116 is sandwiched between the overlapping portions 115d.
Thus, the molded product 100 is obtained.

When performing hot stamping in the second step, in order to ensure the hardenability of the protruding part, that is, in order to make the tensile strength of the protruding part of the press-formed product a predetermined target strength for hot stamping, cooling during molding It is necessary to mold without slowing down.
From this point of view, since both sides of the steel plate are in contact with the mold except for the projecting portion, the material is cooled from both sides and a predetermined cooling rate can be secured.

On the other hand, since the projecting portion is cooled only from one side of the steel plate (the outside of the press-formed product), the cooling rate may decrease and the desired tensile strength may not be obtained. Therefore, when the angle X of the projecting portion of the press-formed product is in the range of 135° to 180°, it is preferable to form the top plate portion with the upper mold 11 after forming the vertical wall portion with the cam mold 21 .

Next, an example of performing the second step by the method of the first example described above will be described. 18 to 21 schematically show each step. This first example method is preferably used when the angle X is greater than 90° and less than or equal to 135°.

18 to 21 show the case where the end portion of the flat portion 611b that becomes the flange portion 113 is bent downward, and the lower die 12 has a shape corresponding thereto. With such a configuration, it becomes easy to put the end of the flat portion 611b between the lower surface of the cam die 21 and the lower die 12 .

As shown in FIGS. 14 to 17, the ends of flat portion 611b do not have to be bent downward. That is, in the manufacturing method of the present embodiment, the end portion of the flange portion of the preform may or may not be bent downward. When the end portion of the portion that will become the flange portion is bent downward, a corresponding recess may be formed in the lower die.

In the apparatus shown in FIG. 18, the upper die 11 is fixed to the plate 13 via the telescopic mechanism 14 which can be extended and retracted. On the other hand, the cam pressing die 15 is fixed to the plate 13 without the telescopic mechanism 14 interposed therebetween.

In this second step, first, as shown in FIG. 18, a preform 610 is arranged between the upper mold 11 and the lower mold 12 .
At this time, it is important to dispose the protruding portion 12a of the lower mold 12 and the preform 610 in a state that they are not in contact with each other.

Next, as shown in FIG. 19, the plate 13 is lowered, and the portion that will become the top plate portion 112 is pressed and restrained by the upper mold 11 and the lower mold 12 (projections 12a). Thus, step (a) is completed.

Next, the plate 13 is further lowered while contracting the extension mechanism 14 . Thereby, as shown in FIG. 20, the cam die 21 is slid toward the convex portion 12a. Since the preform 610 has a protrusion-corresponding portion 605, the protrusion-corresponding portion 605 protrudes upward.

Next, as shown in FIG. 21, the plate 13 is lowered to the bottom dead center, and the cam die 21 and the lower die 12 (projections 12a) press and constrain the vertical wall portions. At this time, the projection-corresponding portion 605 is folded between the upper mold 11 and the cam mold 21 to become the projection 115 . A sandwiching portion 116 is sandwiched between the overlapping portions 115d. Thus, step (b) is completed.
Press molding is completed as described above, and the molded product 100 is obtained.

In the second step, step (a) and step (b) may be completed simultaneously, as described above as the third example of the second step. Steps (a) and (b) can be completed simultaneously by adjusting the shape and placement of the mold.

When performing the second step by hot stamping, when the movement of the dies (the press die 10 and the cam die 21) is completed, the dies and the molded product 100 are separated in order to perform proper quenching in the second step. are preferably in close contact with each other.
The molded product 100 obtained in the second step is post-treated as necessary. The obtained molded article is used in combination with other parts as required.

The second step may be performed using a press die including pins protruding from at least one of the upper die and the lower die of the press die (the same applies to other embodiments). An example of such a second step is schematically shown in FIG. Moreover, FIG. 23 is a photograph showing one process of an example of actual manufacturing.

A press device 40b of FIG. The upper die 11 is formed with a hole 11h into which the pin 16 is inserted when the upper die 11 is lowered. Pins 16 are inserted through holes formed in preform 610 . By performing press molding in the second step in this state, the protruding portion can be formed with high accuracy. In addition, the press die may have a mechanism in which at least part of the pin 16 is accommodated in the lower die 12 when the pin 16 is pressed from above.

When the angle X of the protruding portion of the molded product is greater than 90° and 135° or less, in order to increase the cooling rate of the protruding portion of the press-molded product and obtain the target strength, the top plate portion is formed by the upper die 11. It is preferable to mold the vertical wall portion with the cam die 21 after the molding.

[Manufacturing method by one step]
Another example of the manufacturing method including the first step and the second step described above will be described below. According to the manufacturing method of this example, it is possible to perform the first step and the second step with one apparatus.

This manufacturing method includes a step of heating the material steel plate before the first step. It is carried out using a press device including:
The lower die includes a punch die and two movable plates arranged to sandwich the punch die and movable at least in the vertical direction. The first step includes the following steps (Ia) and (Ib) in this order, and the second step includes the following steps (IIa) and (IIb) in this order.

Here, the vertical direction and the horizontal direction as the directions in which the movable type can move are not only one vertical direction and one horizontal direction, but also an oblique direction in which both the vertical direction and the horizontal direction overlap. may include

Step (Ia) is a step of arranging a material steel plate having a portion corresponding to a pinching portion that serves as a pinching portion between an upper mold, two moving molds, and a lower mold.
As a material steel plate, a material steel plate 600 shown in FIG. 11 or 12 is used. By deforming the material steel plate 600 shown in FIG. 11 or 12, the molded product of the above-described first embodiment can be obtained.

Including a step of heating the material steel plate before the first step, in step (Ia), the material steel plate is placed between the upper die, the two moving dies, and the lower die in a state where the punch die and the material steel sheet do not contact each other. to place.

Step (Ib) lowers the two moving dies together with the two movable plates and moves the two moving dies toward the punching dies, thereby forming two flanges between the two moving dies and the movable plates. This is a step of obtaining a deformed steel sheet in a state in which the part corresponding to the part is sandwiched.
Alternatively, in the step (Ib), the two moving dies are lowered together with the two movable plates, and the two moving dies are moved toward the punch dies to bring the ends of the material steel plate closer to the punch dies for deformation. This is the process of obtaining a steel plate.

Step (IIa) is a step of further moving the two moving dies toward the punch dies to constrain the two vertical wall portions corresponding to the two moving dies and the side portions of the punch dies.

In step (IIa), the two vertical wall portions are constrained by the two movable dies and the side portions of the punch while maintaining the state in which the upper surface of the punch and the deformed steel plate are not in contact with each other.

Step (IIb) is a step of lowering the upper mold to constrain the portion corresponding to the top plate portion with the upper mold and the punch mold.

Through the above-described steps, at least a portion of the portion corresponding to the protrusion is overlapped between the upper mold and the moving mold, thereby sandwiching the portion corresponding to the sandwiching portion, and the protrusion and the sandwiching portion are formed. to form

In addition, in the manufacturing method of the following embodiments, a through hole may be formed in the portion corresponding to the top plate portion. Then, in the second step, movement of the portion corresponding to the top plate portion may be suppressed by passing a pin protruding from the press die through the through hole. The pins usually protrude from one of the upper and lower dies of the press mold.

A through hole through which the pin passes is formed in the other of the press dies. Through-holes are generally formed in the blank stage, but may be formed in other stages prior to the second step. Also in the first step, the movement of the blank may be suppressed by passing the pin through the through hole.

A one-step manufacturing method will be described below with reference to the drawings. The embodiments described below are examples, and the present invention is not limited to the following embodiments, and various variations described above can be applied. In the following description, the same reference numerals may be given to the same parts to omit redundant description.

(Fifth embodiment)
In the fifth embodiment, an example of a one-step manufacturing method for manufacturing a press-formed product will be described. This manufacturing method includes steps (Ia), (Ib), (IIa), and (IIb) described above. A press-formed product manufactured by this manufacturing method includes two flange portions. Therefore, the deformed steel plate includes two flange-corresponding portions that become two flange portions.

A method for manufacturing a molded product according to the fifth embodiment is a method for manufacturing a molded product according to the above-described embodiments, in which a press device including an upper mold, a lower mold, and a moving mold that can move vertically and horizontally The lower die includes a punch die and a movable plate that is arranged to sandwich the punch die and is movable at least in the vertical direction, and heats the material steel plate having a portion corresponding to the sandwiching portion that becomes the sandwiching portion (Ia) placing the material steel plate between the upper die, the moving die, and the lower die in a state in which the punch die and the material steel plate are not in contact with each other; (Ib) lowering the moving die together with the movable plate; (IIa) moving the moving die toward the punch die to bring the edge of the material steel sheet closer to the punch die to obtain a deformed steel sheet; (IIb) a step of restraining a part of the deformed steel plate by the moving die and the side part of the punch die while maintaining a state where the part and the deformed steel plate do not contact; and a step of restraining the part by the upper die and the punch die, and sandwiching the part corresponding to the pinching part by overlapping a part of the deformed steel plate between the upper die and the moving die to form a projecting part. .

In this manufacturing method, the first step and the second step are performed by one press machine.
Therefore, when performing press forming by hot stamping, it is necessary to heat the material steel plate (blank) before the first step.

FIG. 24 shows an example of a press device used in this manufacturing method. The press device 40c of FIG. 24 includes an upper die 50, a lower die 60, two moving dies 51, and a plate 63.
The two moving dies 51 are respectively movable vertically and horizontally. The lower die 60 includes a punch die 61 and two movable plates 64 arranged to sandwich the punch die 61 and movable in the vertical direction.

Note that FIG. 24 shows an example in which the movable plate 64 is connected to the plate 63 via an extension mechanism 64a. As the extension mechanism 64a, the mechanism exemplified for the extension mechanism 61b can be used. The movable plate 64 may be moved independently of the movable mold 51 by a driving device directly attached to the movable plate 64 .

An example of a manufacturing process for manufacturing a press-formed product using the press device 40c will be described below. First, as shown in FIG. 24, the material steel plate B1 is arranged between the upper die 50 and the movable die 51 and the lower die 60 (step (Ia)).

The material steel plate B1 has a portion corresponding to the top plate portion in the center, and includes portions corresponding to the projection portion, portions corresponding to the vertical wall portions, and portions corresponding to the flange portions in order on both sides thereof. In step (Ia), as shown in FIG. 24, the material steel plate B1 is arranged between the upper die 50 and the two moving dies 51 and the lower die 60 in a state in which the punch die 61 and the material steel plate B1 are not in contact with each other. It is important to.

The material steel plate B1 has a portion corresponding to the top plate portion (not shown) in the center, and on both sides thereof, a portion corresponding to a protrusion portion (not shown), a portion corresponding to a vertical wall portion (not shown), and a flange portion. Includes equivalents (not shown). Further, the material steel plate B1 has a sandwiching portion corresponding portion 602 .
As the material steel plate B1, a material steel plate 600 shown in FIG. 11 or 12 can be used. By deforming the material steel plate 600 shown in FIG. 11 or 12, the molded product of the above-described first embodiment can be obtained.

Next, as shown in FIG. 25, the two moving dies 51 are lowered to sandwich the two flange-corresponding portions between the stepped portion 51a of the two moving dies 51 and the movable plate 64. 51 is lowered together with the two movable plates 64, and the two moving dies 51 are moved toward the punch 61 to obtain a deformed steel plate 610 (step (Ib)).
At this time, two flange-like portions are sandwiched between the two movable dies 51 and the movable plate 64 .

In the next second step, by lowering the upper die 50, the portion corresponding to the top plate portion is pressed by the upper die 50 and the punch die 61, and the portion corresponding to the projecting portion is pressed between the upper die 50 and the movable die 51. At least a part of them are overlapped to sandwich the portion corresponding to the sandwiching portion 602 to form the protruding portion 115 .
An example of the second step is described below.

First, as shown in FIG. 26, by further moving the two moving dies 51 toward the punching die 61, the two vertical wall portions are constrained by the two moving dies 51 and the side portions of the punching die 61. (Step (IIa)). By this process, the portion corresponding to the vertical wall portion is restrained in a predetermined position.
At this time, as the movable die 51 moves, the two flange-corresponding portions (flanges) move from the movable plate 64 to the punch die 61 .

As shown in FIG. 26, the punch die 61 includes a portion (stepped portion) having a shape corresponding to the flange portion. In step (IIa), the portion and the movable plate 64 are made substantially flush. In step (IIa), the portion corresponding to the flange portion shifts from being arranged between the movable die 51 and the movable plate 64 to being arranged between the movable die 51 and the punch die 61 .
It is preferable that the distance between the two members sandwiching the portion corresponding to the flange portion is a length obtained by adding about 0.1 to 0.3 mm to the thickness of the portion corresponding to the flange portion. Such a configuration enables smooth movement in the horizontal direction.

Next, as shown in FIG. 27, by lowering the upper die 50, the portion corresponding to the top plate portion is pressed by the upper die 50 and the punch die 61, and projected between the upper die 50 and the movable die 51. At least a part of the portion corresponding to the portion is overlapped and the portion corresponding to the sandwiching portion is sandwiched to form the projecting portion 115 and the sandwiching portion 116, thereby forming the molded product 100 (step (IIb)).

In the step (IIa) described above, the two moving dies 51 are lowered to sandwich the two flange-corresponding portions between the two moving dies 51 and the movable plate 64, and the two moving dies 51 are lowered downward. Descend to a point. After that, by moving the two moving dies 51 in the horizontal direction, the two vertical wall portions are constrained by the two moving dies 51 and the punch die 61 (see FIG. 26).

On the other hand, the two moving dies 51 are lowered to sandwich the two flange-corresponding portions between the two moving dies 51 and the movable plate 64, and then the two moving dies 51 are moved obliquely. Thus, the two vertical wall portion equivalent portions may be restrained by the two moving dies 51 and the punch 61 (see FIG. 26).

Next, as shown in FIG. 28, after moving the movable die 51 in the horizontal direction until it is separated from the projecting portion 115, the movable die 51, the movable plate 64, and the upper die 50 are raised. Then, the molded product 100 is unloaded from the press device 40c. In this manufacturing method using the press device 40c, the movable die 51 and the movable plate 64 can be raised at the same time. Therefore, it is possible to shorten the time required for manufacturing.

In the example described with reference to FIGS. 24 to 28, the entire flange-corresponding portion (or flange portion) is placed on the punch die 61 in steps (IIa) and (IIb). An example in which at least part of the portion corresponding to the flange portion (or the flange portion) is arranged on the movable plate 64 in steps (IIa) and (IIb) will be described below.

The manufacturing process of this example is shown in FIGS. 29 to 33. FIG. Duplicate descriptions may be omitted for portions similar to the examples described with reference to FIGS. 24 to 28 .

FIG. 29 shows an example of a pressing device used in this manufacturing method. A pressing device 40d of FIG. 29 differs from the pressing device 40c shown in FIG. 24 in the shape of the punch die 61 and the length of the movable plate 64. The punch die 61 of the press device 40d does not have a shape on which the entire portion corresponding to the flange portion (or the flange portion) can be placed, and the movable plate 64 is lengthened accordingly.

An example of a manufacturing process for manufacturing a press-formed product using the press device 40d will be described below. First, as shown in FIG. 29, the material steel plate B1 is arranged between the upper die 50 and the movable die 51 and the lower die 60 (step (Ia)).

Next, as shown in FIG. 30, the two moving dies 51 are lowered to obtain the deformed steel plate 610 with the two flange-corresponding portions sandwiched between the two moving dies 51 and the movable plate 64 ( Step (Ib)).

In the next second step, by lowering the upper die 50, the portion corresponding to the top plate portion is pressed by the upper die 50 and the punch die 61, and the portion corresponding to the projecting portion is pressed between the upper die 50 and the movable die 51. At least a part of them are overlapped to sandwich the portion corresponding to the sandwiching portion 602 to form the protruding portion 115 . An example of the second step is described below.

First, as shown in FIG. 31, by moving the two moving dies 51 toward the punching die 61, the two vertical wall portions are constrained by the two moving dies 51 and the side portions of the punching die 61. (Step (IIa)). By this process, the portion corresponding to the vertical wall portion is constrained in a predetermined position. In this manufacturing method, unlike the manufacturing method shown in FIG. 26, the two flange-corresponding portions (flange portions) still exist on the movable plate 64 .

Next, as shown in FIG. 32, by lowering the upper die 50, the portion corresponding to the top plate portion is pressed by the upper die 50 and the punch die 61, and projected between the upper die 50 and the movable die 51. At least a part of the portion corresponding to the portion is overlapped and the portion corresponding to the sandwiching portion is sandwiched to form the projecting portion 115 and the sandwiching portion 116, thereby forming the molded product 100 (step (IIb)).

Next, as shown in FIG. 33, the upper mold 50, movable mold 51 and movable plate 64 are raised. Also, the movable die 51 is moved in the horizontal direction. In this manufacturing method, since the molded product 100 rises as the movable plate 64 rises, the upper die 50, the movable die 51, and the movable plate 64 can be raised at the same time. This manufacturing method using the press device 40d can further reduce the time required for manufacturing.

In the fifth embodiment, an example of manufacturing a molded product including a flange portion is shown. It may be configured as

FIG. 34 shows another example of the material steel plate. In the example of FIG. 34, the material steel plate 700 is composed of a steel plate 701 including a portion corresponding to the top plate portion and a steel plate 702 including a portion corresponding to the vertical wall portion.

35 is a cross-sectional view of the material steel plate 700 of FIG. 34, and is a cross-sectional view of the material steel plate 700 when viewed from a direction parallel to the longitudinal direction of the material steel plate 700 of FIG. As shown in FIG. 35, the material steel plate 700 has a sandwiching portion corresponding portion 703 , a vertical wall portion corresponding portion 704 , a top plate portion corresponding portion 705 , and a projecting portion corresponding portion 706 .

By deforming the material steel plate 700 shown in FIG. 34 or 35, the molded product of the above-described second embodiment can be obtained.

FIG. 36 shows another example of the material steel plate. In the example of FIG. 36, the material steel plate 800 is composed of a steel plate 801 including a portion corresponding to the top plate portion and a steel plate 802 including a portion corresponding to the vertical wall portion.

37 is a cross-sectional view of the material steel plate 800 of FIG. 36, and is a cross-sectional view of the material steel plate 800 when viewed from a direction parallel to the longitudinal direction of the material steel plate 800 of FIG. As shown in FIG. 37, the material steel plate 800 has a sandwiching portion corresponding portion 803 , a vertical wall portion corresponding portion 804 , a top plate portion corresponding portion 805 and a projecting portion corresponding portion 806 .

By deforming the material steel plate 800 shown in FIG. 36 or 37, the molded product of the above-described third embodiment can be obtained.

In the description of the fourth and fifth embodiments above, an example using the material steel plate 600 shown in FIG. 11 or FIG. 12 has been described, but instead of this, the material steel plate 700 or 800 can also be used in the same way. .

By the method for producing a molded article according to the above embodiment, a molded article having good moldability, high strength, and excellent properties in a three-point bending test can be obtained.

[Example]
The invention is illustrated in more detail by the following examples.

(Experimental example 1)
In Experimental Example 1, the molded article according to the present invention was examined for the effect of improving the maximum load with respect to the molded article produced without providing the sandwiching plate portion.

A simulation of a three-point bending test was performed on structural members using the molded product having the sandwiching plate and the molded product not having the sandwiching plate described in the above embodiment. General-purpose FEM (finite element method) software (manufactured by LIVERMORE SOFTWARE TECHNOLOGY, trade name LS-DYNA) was used for the simulation.

FIG. 38 schematically shows a cross-sectional view of the sample used for the simulation. The structural member shown in FIG. 38 comprises the molded product 100 of the above embodiment and a back plate 221 welded to the flange portion 113 thereof. The sample sizes shown in FIG. 38 are as follows.
In FIG. 38, illustration of the pinching plate is omitted.

・Angle X: 180°
・Angle Y: 90°
・Length D of protrusion: 15 mm
・Height of vertical wall Hb1: 60mm
・Width Wt1 between the tips of the two protrusions: 80 mm
・Distance between two vertical walls (width of top plate) Wb1: 50mm (80-2D)
・Width Wp1 of the back plate: 90mm (120-2D)
・Curvature radius at corner portions Ra and Rb: 5 mm
・ Thickness of steel plate: 1.4 mm
・Width of sandwich plate: 10mm
・Longitudinal length: 1000mm

The samples were assumed to consist of steel sheets with a tensile strength of 1500 MPa. It was assumed that the flange portion and back plate of the molded product were fixed by spot welding at a pitch of 40 mm. The samples were designed to have the same mass per unit length in the longitudinal direction, except for the sandwich plate.

FIG. 39 schematically shows the three-point bending test method used in the simulation. A three-point bending test was performed by placing a sample on two fulcrums 5 and pushing the sample from above with an impactor 6 . In the test of Experimental Example 2, the distance S between the two fulcrums 5 was set to 400 mm. The radius of curvature of the fulcrum 5 was set to 30 mm. The radius of curvature of the impactor 6 was set to 150 mm. The impact speed of the impactor 6 was set at 7.5 km/h.

In the three-point bending test, each sample was hit with an impactor 6 from above. The direction of impact of the impactor 6 is indicated by an arrow in FIG.

FIG. 40 is a graph showing the effect of improving the maximum load of a molded product with a sandwich plate relative to a molded product without a sandwich plate portion when the plate thickness of the sandwich plate is changed for samples of the molded product with the sandwich plate. indicates

As shown in FIG. 40, the maximum load of the sample of the molded article having the sandwiching plate is improved by 15% or more compared to the sample of the molded article having no sandwiching plate portion.

As can be seen from Experimental Example 2, in the molded article according to the present invention, the maximum load is remarkably improved as compared with the conventional molded article that does not have sandwiching portions (sandwiching plates).

INDUSTRIAL APPLICABILITY The present invention can be used for molded articles, structural members using the same, and methods for manufacturing molded articles.

40a, 40b, 40c, 40d: Press device 100: Press-formed product 101, 101a, 101b: Steel plate 111: Vertical wall portion 112: Top plate portion 114: Boundary portion 114p: Boundary point 115: Protruding portion 115d: Overlapping portion 116 ：Pinch part

Claims (1)

A vertical wall portion formed of a metal plate, a projecting portion, and a top plate portion adjacent to the vertical wall portion via the projecting portion,
In the projecting portion,
an overlapping portion where a portion of the metal plate extending from the top plate portion and a portion of the metal plate extending from the vertical wall portion overlap;
a sandwiching portion sandwiched between the metal plates forming the overlapping portion;
a tip portion formed by bending the metal plate forming the overlapping portion;
A method for manufacturing a long molded product having
Performed using a press device including an upper die, a lower die, and a moving die that can move vertically and horizontally,
The lower die includes a punch die and a movable plate arranged to sandwich the punch die and movable at least in the vertical direction,
a step of heating a material metal plate having a portion corresponding to the sandwiching portion to be the sandwiching portion;
(Ia) placing the material metal plate between the upper die, the movable die, and the lower die in a state in which the punch die and the material metal plate are not in contact;
(Ib) obtaining a deformed metal plate by lowering the moving die together with the movable plate and moving it toward the punching die to bring the edge of the material metal plate closer to the punching die;
(IIa) By further moving the movable die toward the punch die, a portion of the deformed metal plate is removed while maintaining a state in which the top surface of the punch die and the deformed metal plate are not in contact with each other. a step of constraining by the moving die and the side portion of the punch die;
(IIb) a step of restraining a portion of the deformed metal plate by the upper die and the punch die by lowering the upper die;
including
A method of manufacturing a molded product, wherein the portion corresponding to the sandwiching portion is sandwiched between the upper mold and the movable mold by overlapping a portion of the deformed metal plate to form the projecting portion.

Images