JP2021187259A - Automobile structural component, and method for manufacture thereof - Google Patents

Abstract

To provide an automobile structural component which can easily improve collision resistant performance while suppressing weight increase due to reinforcement.SOLUTION: An automobile structural component has a hollow member which constitutes a closed cross-sectional shape in such a manner that opposite flange parts in two hat cross section members are joined to each other. In the hollow member, when an opposite direction of two top plate parts is so made as to be a height direction, a position in a height direction of a first mating surface that is a joint area between one flange parts, and a position in a height direction of a second mating surface that is a joint area between the other flange parts are different from each other. Further, the automobile structural component comprises: a pair of plates which contacts an outer wall surface of a side wall part on one hat cross member constituting one wall part of the hollow member and an outer wall surface of a side wall part on the other hat cross section member constituting the other wall part of the hollow member respectively; and a connection member which connects the pair of plates, and suppresses increase in a distance between the pair of plates.SELECTED DRAWING: Figure 3

Description

The present invention relates to a structural member (hollow member) for an automobile in which a closed cross-sectional shape is formed by two hat cross-sectional members having a cross-sectional hat shape in which a side wall portion and a flange portion are continuous on both sides of a top plate portion. .. INDUSTRIAL APPLICABILITY The present invention is a technique for providing a structural member having collision resistance particularly against bending deformation due to a collision load input from a direction along the opposite direction of the two top plates.

In recent years, in the automobile field, stricter collision safety standards have been promoted from the viewpoint of occupant protection, and there is a strong demand for expanding the application of high-strength steel and developing vehicles with excellent collision safety performance.
Here, as the form of collision, there are a collision form in which the shaft is crushed and a collision form in which bending deformation occurs. In the collision mode in which the shaft is crushed, the longitudinal direction of the member coincides with the collision direction and the shaft crush occurs, such as a crash box or a front side member that receives a collision load input from the front surface of the automobile. In the collision mode in which bending deformation occurs, a collision load is applied to the side surface of the structural member and the member bends and deforms, as in the case of the B pillar and the side sill in a side collision. In both forms, the member absorbs collision energy by buckling and deforming, and exhibits collision resistance.

As one of the techniques for improving the collision resistance performance, a technique for improving the strength of the structural member by attaching a reinforcing member has been proposed. For example, Patent Document 1 describes a technique for suppressing deformation by providing a plurality of bulkheads inside a structural member and providing a reinforcing material between the bulkheads. Further, in Patent Document 2, a reinforcing member having an L-shaped or U-shaped cross section along the shape of the structural member is arranged inside or outside the structural member, so that the bottom plate is centered on the ridgeline of the structural member. Techniques for reinforcing the portion and the side wall portion are mentioned. Further, Patent Documents 3 and 4 describe a technique for suppressing deformation by filling the inside of a structural member with a foaming material or arranging a reinforcing member filled with foam at a bent portion that is easily deformed at the time of collision. ..

Japanese Unexamined Patent Publication No. 9-20267 WO2017-03091 Gazette Japanese Unexamined Patent Publication No. 2002-36413 Japanese Unexamined Patent Publication No. 2017-159896

However, if a reinforcing member is simply attached to the structural member, the collision resistance is improved, but the number of parts increases, the weight increases more than necessary, and the number of molds increases. There is a cost issue.
Further, in such a method, the weight increase becomes remarkable particularly as the wide area is reinforced with the reinforcing member. Further, from the viewpoint of collision resistance, high-strength steel plates tend to be applied to structural members and reinforcing members, so that there are problems in terms of productivity and cost, such as ensuring dimensional accuracy and reducing weldability.
On the other hand, reinforcement with a foam filler has a problem from the viewpoint of recyclability because there is a concern that the production process will be complicated. In addition, when partially attaching the foam filling member, adhesion is used to attach the member, but there are problems with adhesion such as peeling and deterioration over time during deformation, and it is difficult to secure stable collision resistance. Conceivable.
The present invention has been made focusing on the above points, and an object of the present invention is to provide a structural member for an automobile capable of easily improving collision resistance while suppressing an increase in weight due to reinforcement. do.

The present inventor has made the following invention as a result of diligent studies on a structural member that easily improves the collision resistance performance without increasing the number of parts of the reinforcing member by press working to solve the above problems. ..
In order to solve the problem, one aspect of the present invention is to join the opposing flange portions of two hat cross-sectional members having a cross-sectional hat shape in which the side wall portion and the flange portion are continuous on both sides of the top plate portion. It has a hollow member that constitutes a closed cross-sectional shape, and the hollow member has a height of a first mating surface that is a joint surface between one flange portion when the two top plate portions face each other in the height direction. The position in the vertical direction and the position in the height direction of the second mating surface, which is the joint surface between the other flange portions, are different, and further, the two hat cross-sectional members constituting one wall portion of the hollow member. The outer wall surface of the side wall portion on the side of one of the side wall portions of the hat cross-section member, and the other side wall portion of the side wall portion of the two hat cross-section members constituting the other wall portion of the hollow member. The outer wall surface of the side wall portion has one or more reinforcing members including a pair of plate members that are in contact with each other and a connecting member that connects the pair of plate materials and restrains the distance between the pair of plate materials from increasing. The gist is that.

Another aspect of the present invention is a method for manufacturing a structural member for an automobile having a closed cross-sectional shape, in which two hat cross-sectional members having a cross-sectional hat shape in which a side wall portion and a flange portion are continuous on both sides of a top plate portion, respectively. In the above, when a closed cross-sectional shape is formed by joining the facing flange portions to each other and the facing direction of the two top plate portions is the height direction, the first mating surface which is the joining surface of one flange portion is formed. A hollow member is produced in which the position in the height direction and the position in the height direction of the second mating surface, which is the joint surface between the other flange portions, are different. A nut member that can be screwed into the male screw portion of the shaft member is prepared, and one of the side wall portions of the two hat cross-sectional members constituting one wall portion of the hollow member. The shaft member penetrates the side wall portion on the hat cross-section member side and the side wall portion on the other hat cross-section member side of the side wall portions of the two hat cross-section members constituting the other wall portion of the hollow member. A washer member as a plate material with respect to the end portion of the shaft member protruding from the side wall portion provided with the through hole by opening each possible through hole and allowing the shaft member to penetrate through the two paired through holes. The gist is to attach the nut member and screw and tighten the nut member.

According to the aspect of the present invention, it is possible to provide a structural member for an automobile capable of easily improving the collision resistance performance while suppressing an increase in weight due to reinforcement.
That is, according to the aspect of the present invention, two facing wall portions of the structural member (hollow member) are connected to each other by a pair of plate members and a connecting member. Thereby, according to the aspect of the present invention, it is possible to suppress the deformation of the cross section of the member at the time of collision and to improve the collision load particularly in the bending deformation.
Further, according to the aspect of the present invention, for example, there is a concern that the weldability is lowered due to the increase in strength, and it is possible to improve the collision performance by a simple method while avoiding the joining method by welding.
Further, according to the aspect of the present invention, since the reinforcing member obtained by processing such as pressing or bending is not used, there is an effect of avoiding an increase in weight due to an increase in the number of parts and an increase in cost due to an increase in dies.

It is a perspective view which shows the hollow member which concerns on embodiment based on this invention. It is sectional drawing of the hollow member which concerns on embodiment based on this invention. It is a figure explaining the arrangement of the reinforcing member in this embodiment. It is a perspective view which shows the washer member which constitutes the plate material which concerns on embodiment based on this invention. It is a figure which shows another example of the reinforcing member in this embodiment. It is a side view explaining the three-point bending analysis condition in an Example. It is a perspective view explaining the three-point bending analysis condition in an Example. It is a figure which shows the behavior when a load is applied in the direction from the upper top plate part to the lower top plate part. It is a figure which shows an example of the relationship between a stroke (pushing amount) of a load, and a load. It is a side view which shows the reference of the arrangement of the axis of a plate material (plate) and a connecting member.

Next, an embodiment of the present invention will be described with reference to the drawings.
(composition)
In the present embodiment, the two hat cross-sectional members 10 having a cross-sectional hat shape in which the side wall portions 10B and 11B and the flange portions 10C and 11C are continuous on both sides of the top plate portions 10A and 11A as shown in FIGS. 1 and 2, respectively. With respect to 11, the left and right facing flange portions 10C and 11C are joined to each other to form a closed cross-sectional shape to form a hollow member. The hollow member is referred to as an automobile structural member 1 to be reinforced (hereinafter, also simply referred to as structural member 1). The flange portions 10C and 11C are joined to each other by, for example, spot welding.

The left wall portion (one wall portion) of the hollow member (structural member 1) is composed of the left side wall portions 10B and 11B and the flange portions 10C and 11C of the two hat cross-section members 10 and 11, and the right wall portion. (The other wall portion) is composed of the right side wall portions 10B and 11B and the flange portions 10C and 11C of the two hat cross-section members 10 and 11.
Here, the joining surface between the flange portions 10C and 11C corresponding to each other on the right side is referred to as a first mating surface S2, and the joining surface between the flange portions 10C and 11C facing each other on the left side is referred to as a second mating surface S1.

In the present specification, as shown in FIGS. 1 and 2, the posture in which the top plate portions 10A and 11A of the two hat cross-section members 10 and 11 are vertically opposed to each other will be described. In the present embodiment, it is assumed that an impact from the side of the structural member 1 is easily input to the top plate portion 10A on the upper side of the hat cross-section member 10.
Further, in the present specification, the opposite directions of the two top plate portions 10A and 11A are referred to as height directions.
Then, in the present embodiment, the height L2 of the first mating surface S2 on the right side and the height of the second mating surface S1 on the left side with reference to one of the two top plate portions 10A and 11A. Set so that it is different from L1.

The distance between the two facing top plate portions 10A and 11A is H, and the difference between the height L2 of the first mating surface S2 and the height L1 of the second mating surface S1 is h (= | L1-L2 |). If so, in the present embodiment, the position in the height direction of the height L2 of the first mating surface S2 on the right side and the position in the height direction of the height L1 of the second mating surface S1 on the left side are different. In this case, it is preferable to satisfy the following equation (1).
0 <h ≤ 0.55H ・ ・ ・ (1)
Here, when the height difference h between the first mating surface S2 and the second mating surface S1 is larger than 0.55 times the height H between the top plates, a collision load is applied. As a result, the balance of deformation in the collision process is greatly lost, and the cross section bends in one direction on the left and right (image of crushing a parallelogram), so it is thought that the deformation resistance is greatly reduced.

In the present embodiment, members having the same cross-sectional shape are adopted as the two hat cross-sectional members 10 and 11, and one of the two hat cross-sectional members 10 and 11 is joined by reversing the top and bottom to form a closed cross-sectional shape. It is a hollow member. Therefore, the height of the first mating surface S2 on the right side with respect to the proximal top plate portion 10A is equal to the height of the second mating surface S1 on the left side with respect to the proximal top plate portion 11A. Further, the heights a and b of the left and right mating surfaces S1 and S2 with respect to the center position in the height direction of the hollow member are equal. These values may be different on the left and right.

However, the two hat cross-section members 10 and 11 do not have to have the same dimensions. For example, the height of the lower hat cross-section member 11 may be lower than the height of the upper hat cross-section member 10. The heights of the hat cross-sectional members 10 and 11 are the heights at the average value positions of the heights of the left and right flange portions with respect to the top plate portion. The height ratio of the two hat cross-section members 10 and 11 is, for example, the ratio of the heights of the hat cross-section members 10 and 11 having the higher height to the hat cross-section members 10 and 11 having the lower height. It is set to 1 to 1: 0.5.

Further, the two facing top plate portions 10A and 11A may not be parallel to each other, and the other top plate portion may be inclined with respect to one top plate portion.
In addition, 1 or 2 or more beads extending in the longitudinal direction may be formed on the top plate portions 10A, 11A and the side wall portions 10B, 11B.
Further, although the dimensions of the members in the embodiment are also shown in FIG. 1 and other drawings, these dimensions do not limit the present invention in any way.

In the present embodiment, by providing the reinforcing member to the structural member 1 made of the hollow member having the above-mentioned shape, the collision resistance performance of the structural member 1 is improved in the collision mode in which the structural member 1 is bent and deformed.
As shown in FIG. 3, the reinforcing member of the present embodiment has a pair of plate materials 22 and a connecting member that connects the pair of plate materials 22 and restrains the increase in the distance between the pair of plate materials.
The pair of plate members constitutes the outer wall surface of the side wall portion of one of the side wall portions of the two hat cross-section members constituting the left wall portion of the hollow member, and the wall portion on the right side of the hollow member. It abuts on the outer wall surface of the side wall portion of the other hat cross-section member of the side wall portions of the two hat cross-section members.

That is, in the present embodiment, the pair of plate members 22 and the connecting member connect the side wall portion 10B of one hat cross-section member 10 and the side wall portion 11B of the other hat cross-section member 11.
In the present embodiment, the height L2 of the first mating surface S2, which is the joint surface between the flange portions on the right side, from the top plate portion 10A of one of the two top plate portions 10A and 11A, and the flange portion on the left side. The height L1 of the second mating surface S1 which is a joint surface between the two is different. Therefore, the two side wall portions to which the plate member 22 abuts are the side wall portion of the two side wall portions constituting the left wall portion, which has a relatively large length in the height direction, and the right side wall portion. Of the two side wall portions constituting the above, the side wall portion on the side having a relatively large length in the height direction is used.

The connecting member connects the pair of plate members 22 and restrains the increase in the distance between the pair of plate members 22. By constraining the distance between the pair of plate members 22, the connecting member swells in the out-of-plane direction of the two opposing wall portions of the structural member 1 in response to the input of the collision load to the top plate portions 10A and 11A. Suppresses buckling). That is, by using the reinforcing member of the present embodiment, it is possible to effectively suppress the member cross-sectional deformation at the time of collision, and to improve the load particularly in the bending deformation.
Here, as in the present embodiment, by connecting the side wall portions having relatively large heights with a pair of plate members 22 and a connecting member, the heights L1 and L2 of the two left and right mating surfaces S1 and S2 are connected. Even if they are different, the left and right wall portions of the hollow member can be connected at the shortest distance. Then, more effectively, it is possible to prevent the two opposing wall portions of the structural member 1 from swelling (bending) in the out-of-plane direction.

In FIG. 3, reference numeral P indicates an axial position of the connecting member.
The shaft member 20 is longer than the distance between the two side wall portions 10B and 11B facing each other, and has male screw portions formed at both ends in the axial direction. The male screw portion is formed, for example, from a position inside the side wall portions 10B and 11B toward the tip 20a.
Here, it is preferable that the area of the plate material 22 in contact with the outer surface of the side wall portion 11B is larger than the area of the nut member 21 in contact with the plate material 22. Further, when the surface of the nut member 21 is large, the nut member 21 itself may be used as a substitute for the plate member 22.

Further, through holes that can penetrate the shaft member 20 are coaxially opened in the two side wall portions 11B facing each other.
Then, the shaft member 20 is arranged so as to penetrate the end portions of the through holes opened in the two side wall portions 11B facing each other. The shaft member 20 can be easily attached even after the hollow member is manufactured, for example, by passing it through a through hole on one side wall portion 11B side.
A washer member is attached to an end portion (male screw portion) of each shaft member 20 protruding outward from each side wall portion 11B, and a nut member 21 is screwed. Then, by tightening the nut member 21, the washer member constituting each plate member 22 comes into contact with the outer surface of the side wall portion 11B. The end portion of the shaft member 20 protruding from the nut member 21 may be cut in advance or after the nut member 21 is tightened.

The surface of the washer member facing the side wall portion 11B is configured so that the entire surface is in contact with the side wall portion 11B. Therefore, as shown in FIG. 4, an inclination angle (inclination angle = 95 degrees in FIG. 4) corresponding to the inclination angle of the side wall portion 11B with respect to the top plate portion 11A is given to the surface of the washer member facing the side wall portion 11B. do. Needless to say, when the side wall portions are arranged in parallel, the side wall portion 11B can be sandwiched only by the nut member 21 except for the pair of plate members 22.
In the above description, the washer member and the nut member 21 are attached to both ends of the shaft member 20, respectively, and the nut member 21 is tightened, but the configuration of the reinforcing member is not limited to this.

For example, the shaft member 20 may be composed of a long-axis bolt, and the head of the bolt may be used instead of one of the nut members 21 (or the plate member 22).
Further, as shown in FIG. 5, a shaft member 20 may be used in which a large diameter portion 20A having the same shape as one washer member is previously fixed to one end of the shaft member 20. The large diameter portion 20A of FIG. 5 serves as both a nut member 21 and a washer member among the left and right nut members 21.
Here, in FIG. 3, along the direction described by reference numeral G1, the side wall portions having relatively small heights may be connected to each other by a pair of plate members 22 and a connecting member. In this case, the connecting member is connected. Since they are arranged diagonally, the binding force between the pair of plate members 22 and the connecting member is relatively small.

As shown in FIG. 3, the connecting member of the present embodiment is composed of a shaft member 20 (screw rod) and one nut member 21, and each of the pair of plate members 22 is composed of a washer member. In the example of FIG. 3, a case where the large diameter portion 20A is integrally formed with the right end portion of the shaft member 20 is illustrated, but the right end portion side of the shaft member 20 is also a male screw and a nut member 21. It may be configured with. The following description will be given in the case of a configuration in which the nut member 21 can be screwed into both ends of the shaft member 20.

Further, FIG. 3 illustrates a case where the reinforcing member having the above configuration is provided only at one place in the longitudinal direction (extending direction) of the structural member 1, but the present invention is not limited to this. Reinforcing members having the above configuration may be attached to a plurality of locations on the side wall portions 10B and 11B along the longitudinal direction and the height direction of the structural member 1.
The shaft member 20 is arranged with the axis oriented in the width direction of the top plate portions 10A and 11A, but may not be orthogonal to the longitudinal direction of the structural member 1 in a plan view. The reinforcing member is preferably provided in a direction intersecting the longitudinal direction of the structural member 1 (for example, in the vertical direction) in the vicinity of a position where it is presumed that a collision load is likely to be applied.

Further, regardless of the height of the hat cross-sectional members 10 and 11, the position where the pair of plate members 22 (washer members) are provided is in the height direction from the mating surface proximal to the upper top plate portion 10A to which the impact is input. It is preferable to arrange the plate material 22 so that at least a part of the plate material 22 is inserted in the side wall portions 10B and 11B within 20 mm. This is because it is possible to reinforce more effectively if the reinforcing member is provided close to the mating surface proximal to the upper top plate portion 10A where an impact is easily input.
Further, the position where the pair of plate members 22 (washer members) is provided is, for example, the top plate on the side where it is highly likely that a collision load is applied along the directions in which the two top plate portions 10A and 11A face each other. When viewed from the surface position of the portions 10A and 11A and the facing directions of the two facing side wall portions 10B and 11B, a part of the plate material 22 is positioned so as to overlap in the vertical direction (opposite directions of the two top plate portions 10A and 11A). Deploy.

Alternatively, the position where the pair of plate members 22 are provided is, for example, the surface position in the top plate portions 10A, 11A where it is presumed that a collision load toward the opposite directions of the two top plate portions 10A, 11A is likely to be applied. The side wall portions 10B and 11B are arranged so as to be positioned at the center position (position of the shaft member 20) in the deformed region where the side wall portions 10B and 11B are deformed when a preset collision load is applied.
The surface position of the top plate portion 10A, which is presumed to have a high possibility of being loaded with a collision load, is determined by, for example, a side collision of the vehicle based on past accident information based on the vehicle position in which the structural member 1 is arranged. It is estimated based on which part of the target structural member 1 the collision load is likely to be input to.

Further, the deformation region is specified by analyzing the deformation position of the member by, for example, FEM analysis. As the preset collision load, the allowable collision load required for the collision resistance at the position where the structural member 1 is used is adopted.
In the structural member 1 provided with the above-mentioned reinforcing member, in addition to the effect of making the heights of the left and right mating surfaces different, a pair of plate members 22 abutting on the two facing side wall portions 11B are connected to the connecting member. By connecting with, the outward bulge (buckling) of the two facing wall portions due to the collision load input in the facing directions of the two top plate portions 10A and 11A is along the axial direction of the connecting member. It is suppressed by the tensile force. Therefore, it is possible to suppress deformation at the time of collision with a reinforcing member having a small weight. That is, according to the present embodiment, it is possible to effectively suppress the cross-sectional deformation of the member at the time of collision, and to improve the maximum load particularly in the bending deformation.

Further, according to the present embodiment, a pair of plate members 22 constituting the reinforcing member is attached to the structural member 1 by screwing the nut member 21 into the shaft member 20 (screw rod). Therefore, welding work is not required to attach the reinforcing member to the structural member 1. As a result, according to the present embodiment, there is a concern that the weldability is deteriorated due to the increase in strength of the structural member 1, and the collision resistance is improved by a simple mounting method of screwing while avoiding the joining method by welding. Is possible.
For example, after the structural member 1 is manufactured, it is possible to easily reinforce it with a reinforcing member.
Although each plate member 22 may be fixed to the end of the shaft member 20 by welding, mounting by screwing has a simpler structure.
Further, according to the present embodiment, since the reinforcing member is not provided by processing such as pressing or bending, there is an effect of avoiding an increase in weight due to an increase in the number of parts and an increase in cost due to an increase in dies.

(effect)
In this embodiment, the following effects are obtained.
(1) In the present embodiment, two hat cross-sectional members having a cross-sectional hat shape in which a side wall portion and a flange portion are continuous on both sides of a top plate portion are joined to each other to form a closed cross-sectional shape. The hollow member has a hollow member, and when the opposite direction of the two top plate portions is the height direction, the hollow member has a position in the height direction of the first mating surface which is a joint surface between the flange portions. , The position in the height direction of the second mating surface, which is the joint surface between the other flange portions, is different, and further, among the side wall portions of the two hat cross-sectional members constituting one wall portion of the hollow member. The outer wall surface of the side wall portion on the side of one hat cross-section member, and the outside of the side wall portion on the other side of the side wall portion of the two hat cross-section members constituting the other wall portion of the hollow member. The wall surface has one or more reinforcing members including a pair of plate members that come into contact with each other and a connecting member that connects the pair of plate materials and restrains the distance between the pair of plate materials from increasing.

According to this configuration, it is possible to provide a structural member for an automobile capable of easily improving the collision resistance performance while suppressing an increase in weight due to reinforcement.
That is, in the present embodiment, two facing wall portions of the structural member (hollow member) are connected to each other by a pair of plate members and a connecting member. Thereby, according to the aspect of the present invention, it is possible to suppress the deformation of the cross section of the member at the time of collision and to improve the collision load particularly in the bending deformation.
Further, according to this configuration, for example, there is a concern that the weldability is deteriorated due to the increase in strength, and it is possible to improve the collision performance by a simple method while avoiding the joining method by welding.
Further, according to this configuration, since the reinforcing member obtained by processing such as pressing or bending is not used, there is an effect that the weight increase due to the increase in the number of parts and the cost increase due to the increase in the mold are avoided.

(2) In the present embodiment, the connecting member extends in the width direction of the top plate portion and penetrates the two side wall portions and the pair of plate materials that come into contact with the plate material, and has a male screw portion at the axial end portion. It is composed of a formed shaft member and a nut member that is screwed into a male screw portion of the shaft member and faces the outer wall surface of the side wall portion with the plate material interposed therebetween.
According to this configuration, a pair of plate members 22 constituting the reinforcing member is attached to the structural member 1 by screwing the nut member 21 into the shaft member 20 (screw rod). Therefore, welding work is not required to attach the reinforcing member to the structural member 1. As a result, according to the present embodiment, there is a concern that the weldability is deteriorated due to the increase in strength of the structural member 1, and the collision resistance is improved by a simple mounting method of screwing while avoiding the joining method by welding. Is possible.
Further, according to this configuration, even when the side wall portions of the two hat cross-sectional members are connected to each other by the connecting portion to be reinforced, or even after the structural member 1 is manufactured and formed into a closed cross-sectional shape, it can be easily performed. It is possible to reinforce with a reinforcing member.

(3) In the present embodiment, one end of the connecting member is integrally formed with one of the pair of plate materials, and the connecting member extends in the width direction of the top plate and the plate material comes into contact with the top plate. A shaft member that penetrates one side wall portion and the other plate material of the pair of plate materials and has a male screw portion formed at an axial end portion on the other plate material side, and a shaft member that is screwed into the male screw portion of the shaft member. The side wall is composed of a nut member facing the outer wall surface with the other plate material interposed therebetween.
According to this configuration, a pair of plate members 22 constituting the reinforcing member is attached to the structural member 1 by screwing the nut member 21 into the shaft member 20 (screw rod). Therefore, welding work is not required to attach the reinforcing member to the structural member 1. As a result, according to the present embodiment, there is a concern that the weldability is deteriorated due to the increase in strength of the structural member 1, and the collision resistance is improved by a simple mounting method of screwing while avoiding the joining method by welding. Is possible.
Further, according to this configuration, even when the side wall portions of the two hat cross-sectional members are connected to each other by the connecting portion to be reinforced, or even after the structural member 1 is manufactured and formed into a closed cross-sectional shape, it can be easily performed. It is possible to reinforce with a reinforcing member.

(4) The present embodiment is a method for manufacturing a structural member for an automobile having a closed cross-sectional shape, wherein two hat cross-sectional members having a cross-sectional hat shape in which a side wall portion and a flange portion are continuous on both sides of a top plate portion, respectively. A hollow member having a closed cross-sectional shape is manufactured by joining the flange portions to each other, and a shaft member having a male screw portion formed at at least one end of both ends in the axial direction and a nut that can be screwed into the male screw portion of the shaft member. A member is prepared, and one of the side wall portions of the two hat cross-section members constituting the left wall portion of the hollow member constitutes the side wall portion of the hat cross-section member and the right wall portion of the hollow member. A through hole through which the shaft member can penetrate is opened in each of the side wall portions of the other hat cross-section member of the side wall portions of the two hat cross-section members, and the shaft member is inserted into the pair of through holes. A washer member as a plate material is attached to the end portion of the shaft member which is penetrated and protrudes from the side wall portion provided with the through hole, and the nut member is screwed and tightened.
According to this configuration, it is possible to provide a structural member for an automobile capable of easily improving the collision resistance performance while suppressing an increase in weight due to reinforcement.

[Example 1]
The inventors analyzed in detail the deformation behavior of the parts in the three-point bending test by FEM analysis using a hollow member made of a cross-section member of a mating hat having a shape as shown in FIGS. 1 and 2. The three-point bending test conditions are shown in FIGS. 6 and 7. That is, the analysis condition of the three-point bending is a condition that two points on the lower surface of the structural member 1 separated in the longitudinal direction are supported by the support member 31, and a load is applied to the central portion in the longitudinal direction from the upper side by the punch 30.
As the upper and lower hat cross-section members 10 and 11, steel plates having a thickness of 1.2 mm and a tensile strength of 1180 MPa were used.

<Comparison example>
As a comparative component, as shown in FIG. 2, a hollow member having the mating surfaces S1 and S2 of the left and right flange portions arranged in the height direction (difference in the height direction between the mating surfaces h = 40 mm) was used. The mating surfaces have equal values of distances a and b in the height direction from the center position in the height direction of the structural member. However, in the comparative parts, reinforcement is not performed with a pair of plate materials and connecting members.
FIG. 8 shows the deformation behavior at the time of collision, and FIG. 9 shows the relationship between the load and the stroke.
In the comparative parts, as shown on the left side of FIG. 8, an impact is applied, and as the stroke (pushing amount) increases, deformation at the punch contact portion, which is the central portion in the longitudinal direction of the member, starts, and the collision load increases. did. The stroke amount is the amount of pushing downward, with the state where the punch is in contact with the top plate portion being 0 mm. Then, as the stroke increased, the cross-sectional deformation progressed while the side wall portion was opened, and after reaching the maximum load, the load decreased while the cross-section was greatly opened.

<Invention Example>
As shown in FIG. 3, the invention component is a component in which the above comparative component is reinforced with a screw rod 20, a nut member 21, and a plate material 22 constituting a reinforcing member (a pair of plate members and a connecting member).
A steel material made of SS400 of M6 was used for the screw rod and the nut member 21 constituting the reinforcing member. The plate material 22 was made of a steel material made of SS400. As shown in FIG. 4, the size of the plate material 22 is a plate material 22 thicker than the side wall portions 10B and 11B. It is preferable that the plate material 22 is set so that the bending rigidity is higher than that of the side wall portions 10B and 11B.

The position of the reinforcing member is set below the punch 30 so that the shaft P of the screw rod is arranged at the center in the height direction of the hollow member.
Looking at the behavior at the time of collision in this invention example, as shown on the right side of FIG. 8, the cross-sectional deformation progresses while the opening of the side wall portion is kept small as compared with the comparative example, and the cross-sectional deformation progresses at the time of collision. The load was found to be increasing. From this study, the inventors have found that it is effective to suppress the change in the cross-sectional shape due to the opening (swelling outward) of the side wall portion in order to improve the deformation load at the time of collision.

Here, as in the comparative example, the portion where the cross section is greatly opened in the parts having different height positions of the left and right mating surfaces is hung on the two opposite side wall portions of both the hat cross section members of the two hat cross section members. It is necessary to control the change of the two hat cross-section members. For example, when restraining with a reinforcing member, it is extremely difficult to join the reinforcing member by welding from the inside after joining the two hat cross-section members to form a hollow member, and three pieces are formed on the mating surfaces S1 and S2 of the left and right flange portions. If the reinforcing members are joined by stacking, the effect of suppressing the cross-sectional shape is reduced, or the shape of the reinforcing parts becomes complicated or large. Therefore, it has been found that the cross-section control technique by the reinforcing method based on the present invention is effective as a method for easily controlling the change of the two parts. Further, this reinforcing method is considered to have an advantage that it is not necessary to consider the deterioration of weldability, which is a problem with high-strength materials.

[Example 2]
Next, the load load position by the punch 30 and the mounting position of the plate material 22 (the center position of the plate material 22 (the position of the shaft P of the shaft member 20)) are changed as shown in Table 1, and the maximum load and the average load are obtained. I tried it.
Here, the stroke was set to 100 mm. Further, in Table 1, the average load is the average value of the load in all strokes, and corresponds to the energy absorption capacity for impact.
Further, with the load direction as the y-axis, the xy coordinate axes as shown in FIGS. 7 and 10 are set, the position of y = 0 is the center position in the height direction of the structural member, and x = 0 is directly below the load direction by punching. Set to.

No. in Table 1 As can be seen from 1, 6 and 7, the maximum load and the average load are improved as compared with the comparative example by providing the plate material 22 in the vicinity of the longitudinal direction directly under the load (x = 0) in the side view. I understand. In addition, No. It was found that the average load was improved as compared with the comparative example even when the plate material 22 was arranged so as to be shifted from directly under the load to 60 mm in the longitudinal direction as in 4 and 5.
As described above, it was found that the energy absorption capacity can be set higher than that in the comparative example by providing the pair of plate members and the connecting member while making the heights of the left and right mating surfaces S1 and S2 different.
Further, in the present invention, a connecting member is provided so as to straddle between the two hat cross-section members. However, by forming the connecting member with a screw rod and a nut member, the two hat cross-section members are joined. Even after the structural member 1 (hollow member) is formed, it can be easily attached and the reinforcement adjustment is easy.

1 Structural members for automobiles (hollow members)
10, 11 Hat cross-section members 10, 11 Hat cross-section members 10A, 11A Top plate portion 10B, 11B Side wall portion 10C, 11C Flange portion 20 Shaft member (screw rod)
20A Large diameter part 20a Tip 21 Nut member 22 Plate material P axis S1 Second mating surface S2 First mating surface h Difference between mating surfaces

Claims (4)

Two hat cross-sectional members having a cross-sectional hat shape in which the side wall portion and the flange portion are continuous on both sides of the top plate portion have hollow members that form a closed cross-sectional shape by joining the opposing flange portions to each other.
In the hollow member, when the opposite direction of the two top plate portions is the height direction, the position in the height direction of the first mating surface, which is the joint surface between the flange portions of one, and the flange portions of the other. The position in the height direction of the second mating surface, which is the joint surface, is different.
In addition,
The outer wall surface of the side wall portion on the hat cross-section member side of the side wall portions of the two hat cross-section members constituting one wall portion of the hollow member, and the other wall portion of the hollow member. A pair of plate materials that abut on the outer wall surface of the side wall portion on the other side of the side wall portion of the two hat cross-section members, respectively.
A connecting member that connects the pair of plates and restrains the distance between the pair of plates from increasing, and
A structural member for an automobile, characterized in that it has one or more reinforcing members. The connecting member includes a shaft member extending in the width direction of the top plate portion and penetrating the two side wall portions to which the plate material abuts and the pair of plate members and having a male screw portion formed at an axial end portion. The structural member for an automobile according to claim 1, wherein the nut member is screwed into a male screw portion of the shaft member and faces the outer wall surface of the side wall portion with the plate material interposed therebetween. One end of the connecting member is integrally formed with one of the pair of plate materials, and the two side wall portions extending in the width direction of the top plate portion and the plate material abuts on the top plate portion and the pair of plate materials. A shaft member that penetrates the other plate material of the above and has a male screw portion formed at the axial end portion on the other plate material side, and the other shaft member that is screwed into the male screw portion of the shaft member and is screwed onto the side wall portion on the outer wall surface. The structural member for an automobile according to claim 1, further comprising a nut member facing each other across the plate material. A method for manufacturing structural members for automobiles with a closed cross-section.
In two hat cross-sectional members having a cross-sectional hat shape in which the side wall portion and the flange portion are continuous on both sides of the top plate portion, a closed cross-sectional shape is formed in which the opposing flange portions are joined to each other, and the two top plate portions face each other. When the direction of the flange is the height direction, the position in the height direction of the first mating surface which is the joining surface between the one flange portions and the height direction of the second mating surface which is the joining surface between the other flange portions. Create a hollow member that is different from the position of
A shaft member having a male screw portion formed at at least one end of both ends in the axial direction and a nut member screwable to the male screw portion of the shaft member are prepared.
One of the side wall portions of the two hat cross-section members constituting one wall portion of the hollow member, the side wall portion on the hat cross-section member side, and the two hats constituting the other wall portion of the hollow member. A through hole through which the shaft member can penetrate is opened in each of the side wall portions on the other side of the side wall portion of the cross-sectional member on the side of the hat cross-sectional member.
The shaft member is passed through the two paired through holes, and the washer member as a plate material is attached to the end of the shaft member protruding from the side wall portion provided with the through hole, and the nut member is screwed. A method for manufacturing a structural member for an automobile, which comprises tightening.

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