JP2016113083A - Vehicle frame structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle frame structure that can improve EA efficiency at bending deformation and EA efficiency at axial compression deformation by using a single reinforcing member.SOLUTION: A first reinforcing member 30 which forms five vertically-adjacent sub-closed cross sections c in cooperation with a main closed cross section C comprises: a first partitioning wall 36 having a first compression-side partitioning part 36a and a first tension-side partitioning part 36b; and a second partitioning wall 37 having a second compression-side partitioning part 37a and a second tension-side partitioning part 37b. A vertical interval between tension-side ridges 36t, 37t is formed smaller than a vertical interval between compression-side ridges 36s, 37s, and when a load is inputted, a difference between lateral widths of the first and second compression-side partitioning parts 36a, 37a at a front end portion of a front side region 2a and lateral widths of the first and second tension-side partitioning parts 36b, 37b is formed smaller than a difference between lateral widths of the first and second compression-side partitioning parts 36a, 37a at a latter-half portion of the front side region 2a and lateral widths of the first and second tension-side partitioning parts 36b, 37b.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a vehicle frame structure, and more particularly to a vehicle frame structure in which a compression side portion and a tension side portion cooperate to form a substantially rectangular main closed section.

Conventionally, a crush can (also called a crush box) that can be axially deformed and deformed is provided at the tip of the front side frame made of high-strength steel plate, and can be actively bent and deformed from the middle to the rear end of the front side frame. By adopting a plurality of shock absorbing mechanisms, the amount of shock energy absorbed at the time of collision is increased to protect the occupant during a front collision (Patent Document 1).
In such an impact absorption mechanism, since the impact load absorbed by the bending deformation of the front side frame occupies most of the entire energy absorption amount, the energy absorption characteristic due to the bending deformation is greater than the energy absorption characteristic due to the compression deformation. ) Large impact on performance.

  Therefore, the present applicant contributes to bending strength by making the aspect ratio of the plurality of sub closed cross sections formed so as to be adjacent in the vertical direction in cooperation with the main closed cross section of the frame larger than the aspect ratio. The frame structure that can expand the frame area, in other words, the frame structure that can maintain the allowable limit load in the correlation between the load that can be supported and the deformation stroke (hereinafter referred to as FS characteristics) for a certain stroke has already been proposed. doing.

  In the frame structure of Patent Document 2, a plurality of elongated portions having an elongated rectangular cross-section perpendicular to the longitudinal direction is set so that the neutral surface between the compression side and the tension side at the time of load input is orthogonal to the long side. The frame structure for a vehicle is arranged in such a manner that long sides separated from each other in adjacent elongated portions are connected by a connecting portion, and the long sides separated from each other in the adjacent elongated shape portion on the compression side than the connecting portion. Are provided with tilt-inhibiting members that are in contact with each other to suppress tilting of the elongated portion in a direction perpendicular to the long side.

Japanese Patent No. 5504820 Japanese Patent Application No. 2014-113803

The present inventor analyzed the mechanism of the deformation behavior of the frame by CAE (Computer Aided Engineering) in examining the buckling phenomenon of the frame having a vertically long rectangular cross section.
First, the basic concept of this analysis will be described.
As shown in FIG. 13, a closed cross-section steel frame model M extending in the longitudinal direction and a load applying means T for bending the axis of the frame model M in a state where both ends of the frame model M are sandwiched are prepared. Then, the displacement of the load point P and the reaction force of the load point P were analyzed.
As shown in FIGS. 13, 14 (a), and 14 (b), the load applying means T is formed with a support portion Ta that can be rotated about the pivot portion R and a load point P that applies a load. In addition, a support portion Tb that can be rotated while being displaced toward the support portion Ta side, and a straight line connecting the pivot portion R and the load point P is offset from the axis of the frame model M by 50 mm. In addition, each wall part of the frame model M includes a compression side wall part Ma to which a compressive load acts, a tension side wall part Mb to which a tensile load acts, an upper end wall part Mc and a lower end wall that connect the upper and lower end parts of each wall part, respectively. Part Md.

Next, an analysis result based on the FS characteristic of the frame model M will be described.
As shown in FIG. 15, in the closed cross-sectional frame extending in the longitudinal direction, a maximum (allowable limit) load of 26 kN that becomes a peak at a predetermined displacement is generated, and the load rapidly decreases after buckling.
As shown in FIG. 16, the mechanism of occurrence of buckling is assumed as follows.
By applying a load that exceeds the allowable limit, an elastic buckling wave W is generated in the compression side wall portion Ma, and this elastic buckling wave W propagates to the upper end wall portion Mc and the lower end wall portion Md. Out-of-plane deformation occurs in the mountain region n of the upper end wall portion Mc and the lower end wall portion Md corresponding to the valley region m of the buckling wave W, respectively. As a result, the upper end wall portion Mc and the lower end wall portion Md bulge out in the out-of-plane direction, and the compression side wall portion Ma is folded in two to buckle the closed cross-section frame. That is, by attenuating the elastic buckling wave W of the compression side wall portion Ma, the upper end wall portion Mc, and the lower end wall portion Md, the allowable limit load can be increased to the plastic region of the material, and the EA efficiency in bending deformation is increased. can do.

The frame structure of Patent Document 2 can increase the allowable limit load that causes buckling in the front side frame because the period of the elastic buckling wave can be reduced by making the sub-cross section aspect ratio larger than the aspect ratio. This allowable limit load can be maintained for a certain stroke.
However, this frame structure is a mechanism that absorbs the impact load that is not absorbed by the axial compression deformation of the crash can by the bending deformation of the front side frame, so the part separated from the bending deformation starting part of the front side drain (frame) is It does not make a sufficient contribution to the increase in EA efficiency in bending deformation.

  Further, when the length of one side of the cross section orthogonal to the load input direction (longitudinal direction) is long, the wavelength of the axial compressive load becomes longer and the amplitude increases, so that the EA efficiency in the axial compressive deformation deteriorates. The front end portion of the front side drain whose side length is not uniform contributes little to increasing the EA efficiency in axial compression deformation.

  An object of the present invention is to provide a vehicle frame structure or the like that can improve EA efficiency in bending deformation and EA efficiency in axial compression deformation with a single reinforcing member.

  The vehicle frame structure according to claim 1 includes a compression side portion including a longitudinal compression side wall portion on which a compression load acts, and a vertical tension side wall portion on which a tensile load acts, and cooperates with the compression side portion. A tension side portion that forms a main closed cross section whose cross section orthogonal to the longitudinal direction is substantially rectangular, and a reinforcing member that forms a plurality of sub closed cross sections adjacent to each other in the vertical direction in cooperation with the main closed cross section. In the vehicle frame, the reinforcing member is a first partition wall portion that connects the compression side wall portion and the tension side wall portion to partition the main closed section up and down, and extends from the compression side wall portion to the tension side. A first partition wall portion having a first compression side partition portion and a first tension side partition portion extending from the tension side wall portion toward the compression side; and the compression side wall portion and the tension side wall portion at a position below the first partition wall portion. Are connected to each other to partition the main closed section vertically. A second partition wall portion having a second compression side partition portion extending from the compression side wall portion toward the tension side and a second tension side partition portion extending from the tension side wall portion toward the compression side; When the vertical distance of the compression side end of the tension side partition is formed smaller than the vertical distance of the tension side end of the first and second compression side partitions, and a load is input to the vehicle frame from the longitudinal direction. The difference between the lateral width of the first and second compression side partition portions of the load input side portion and the lateral width of the first and second tension side partition portions is greater than the load input side portion with respect to the load input side portion. It is characterized in that it is formed to be smaller than the difference between the lateral width of the first and second compression side partitioning portions on the side opposite to the input portion and the lateral width of the first and second tension side partitioning portions.

The vehicle frame structure includes first and second horizontal partition walls that form a plurality of sub-closed cross-sections that are adjacent in the vertical direction within the main closed cross-section, so the aspect ratio of the sub-closed cross-section is 1 or less. The allowable limit load can be increased by adjustment, and this allowable limit load can be maintained for a certain stroke.
Since the vertical interval between the compression side end portions of the first and second tension side partition portions is smaller than the vertical interval between the tension side end portions of the first and second compression side partition portions, The truss shape can be formed by the contact of the compression side end portions of the supported first and second tension side partition portions, and the cross-sectional collapse accompanying the bending deformation can be suppressed.
The difference between the lateral width of the first and second compression side partition portions of the load input side portion and the lateral width of the first and second tension side partition portions is the load input to the load input side portion rather than the load input side portion. The cross section perpendicular to the longitudinal direction is formed so as to be smaller than the difference between the lateral width of the first and second compression side partitioning portions and the lateral width of the first and second tension side partitioning portions on the side opposite to the portion. The length of one side can be shortened, and the wavelength of the axial compression load can be shortened and the amplitude can be decreased.

According to a second aspect of the present invention, in the first aspect of the present invention, in the vicinity of the load input portion, the lateral width of the first and second compression side partition portions and the first and second tension side partition portions are closer to the load input portion side. It is characterized in that it is formed so that the difference from the lateral width of is small.
According to this configuration, a load that is not absorbed by the axial compression deformation can be continuously transmitted to the bending deformation portion, and the load can be efficiently absorbed at the bending deformation portion.

According to a third aspect of the present invention, in the first or second aspect of the invention, in the load input portion, the lateral width of the first and second compression side partition portions and the lateral width of the first and second tension side partition portions are the same dimension. It is characterized by being formed.
According to this configuration, the length of one side of the cross section orthogonal to the longitudinal direction can be minimized, and the EA efficiency in axial compression deformation can be increased.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the neutral surface of compression and tension at the time of load input is the tension side end of the first and second compression side partitions. And the compression side end portions of the first and second tension side partition portions.
According to this structure, the truss shape by contact | abutting of the compression side edge part of the 1st, 2nd tension | pulling side partition part supported by the tension | pulling side wall part can be formed reliably, suppressing an out-of-plane deformation | transformation.

  According to the vehicle frame structure of the present invention, EA efficiency in bending deformation and EA efficiency in axial compression deformation can be improved with a single reinforcing member.

It is the side view which looked at the front side frame concerning Example 1 from the engine room inside. It is a top view of a right front side frame. It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a disassembled perspective view of a right front side frame. It is a perspective view of the 1st reinforcement member. It is a perspective view of the 2nd reinforcement member. It is a left side view of a 1st, 2nd reinforcement member and an engine mount reinforcement member. It is the figure which looked at the 1st, 2nd reinforcement member and the engine mount reinforcement member from diagonally right above. It is a top view which shows the state of the vehicle before the input of a front impact load. It is a top view which shows the state of the vehicle after the input of a front impact load. It is the XII-XII sectional view taken on the line of FIG. It is explanatory drawing of the analysis method which concerns on the deformation | transformation behavior of a closed cross-section frame. It is a deformation | transformation behavior of a closed cross-sectional frame, Comprising: (a) shows the state figure before giving a load, (b) has shown the state figure after giving a load. It is a graph which shows the FS characteristic of the conventional closed section frame. It is a figure explaining elastic buckling of a closed section frame.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies a case where the present invention is applied to a front side frame of a vehicle, and does not limit the present invention, its application, or its use.
In the figure, the direction of arrow F is the front, the direction of arrow L is the left, and the direction of arrow U is the top.

Hereinafter, Example 1 of the present invention will be described with reference to FIGS.
First, the front body structure in which the front side frame is installed will be briefly described.
As shown in FIG. 1, a vehicle V includes a dash panel 1 that extends and partitions an engine room E and a vehicle compartment in a vertical direction and a vehicle width direction, and a front side frame 2 that extends in the front-rear direction at a front position of the dash panel 1. A suspension tower 3 standing in a tower shape at a side position of the front side frame 2, and an apron 4 that extends and connects the suspension tower 3 and the dash panel 1 in the vertical direction and the front-rear direction; An apron rain member 5 extending in the front-rear direction at the upper end of the apron portion 4 is provided. In addition, since it is a right-and-left object structure, it mainly demonstrates the vehicle body right side structure and abbreviate | omits description about the vehicle body left side structure.

A crash can 6 is installed at the front end of the front side frame 2 to compress and deform (axially compress) when receiving a front impact load to absorb part of the collision energy.
A substantially cylindrical engine mount device 7 is installed in the front-rear direction intermediate portion of the front side frame 2, and a power unit (not shown) is elastically supported by the engine mount device 7. A mount rain 8 (engine mount reinforcing member) is installed in the front side frame 2 below the engine mount device 7 in order to increase the mounting rigidity of the engine mount device 7. A subframe mounting bracket 9 for attaching a suspension subframe (not shown) is joined and fixed to the rear lower surface of the front side frame 2.

Next, the front side frame 2 will be described in detail.
As shown in FIGS. 2 to 5, the front side frame 2 is formed by press-forming a high-tensile steel plate, and has a substantially rectangular main closed section C that is long in the vertical direction and has a so-called aspect ratio larger than the aspect ratio. Is configured. The front side frame 2 has a front region 2a in which the first reinforcing member 30 is disposed and a mount rain 8 connected to the rear end of the front region 2a according to the function of each region in the front-rear direction. After the mounting region 2b, the intermediate region 2c connected to the rear end of the mounting region 2b and the second reinforcing member 40, and the third reinforcing member 50 connected to the rear end of the intermediate region 2c. Side region 2d.

The front side region 2a is bent and deformed to the right (outside in the vehicle width direction) by the first bead portion 11f that is axially compressed and deformed by the impact load that is not absorbed by the crash can 6 at the time of the front collision, and the second portion extends vertically. It is formed as follows.
The mount region 2b is formed so as to be supported in a state in which the mount rain 8 is accommodated in the main closed section C, and the intermediate region 2c is formed by a second bead portion 23f whose rear end side portion extends vertically during a front collision. The rear end portion is formed to support the subframe mounting bracket 9 while being bent and deformed to the left (in the vehicle width direction) side. The rear region 2d is formed so that the rear end side portion is bent and deformed outward in the vehicle width direction by the third bead portion 14f extending vertically, and the rear end portion is fixed to the dash panel 1 at the time of a front collision. ing.

As shown in FIGS. 2 to 5, the front side frame 2 is divided into left and right parts by an outer member 10 having a substantially hat-shaped cross section and an inner member 20 having a substantially panel shape.
First, the outer member 10 will be described.
The outer member 10 constitutes a first outer portion 11 (compression side portion) that constitutes the right portion of the front region 2a, a second outer portion 12 that constitutes the right portion of the mount region 2b, and a right portion of the intermediate region 2c. The third outer portion 13 (tensile side portion) and the fourth outer portion 14 (compression side portion) constituting the right side portion of the rear region 2d are integrally formed.

The first outer portion 11 includes a compressed side wall portion 11a along a plane substantially orthogonal to the left-right direction, an upper end wall portion 11b extending leftward from the upper end portion of the compressed side wall portion 11a, and a lower end portion of the compressed side wall portion 11a. A lower end wall portion 11c extending leftward is integrally provided.
The compression side wall part 11a is provided with the 1st bead part 11f dented in the main closed cross section C side in the rear-end part. The first bead portion 11f is formed so as to be substantially orthogonal to the front-rear direction over the vertical direction of the compression side wall portion 11a. The upper end wall portion 11b and the lower end wall portion 11c are respectively provided with an upper flange portion 11d extending upward from the left end portion and a lower flange portion 11e extending downward from the left end portion.

The second outer portion 12 includes a right side wall portion 12a along a plane substantially orthogonal to the left and right direction, an upper end wall portion 12b extending leftward from the upper end portion of the right side wall portion 12a, and a lower end portion of the right side wall portion 12a. A lower end wall portion 12c extending leftward, an upper flange portion 12d extending upward from the left end portion of the upper end wall portion 12b, and a lower flange portion 12e extending downward from the left end portion of the lower end wall portion 12c are provided.
The third outer portion 13 includes a tensile side wall portion 13a along a plane substantially orthogonal to the left-right direction, an upper end wall portion 13b extending leftward from the upper end portion of the tensile side wall portion 13a, and a lower end portion of the tensile side wall portion 13a. A lower end wall portion 13c extending leftward, an upper flange portion 13d extending upward from the left end portion of the upper end wall portion 13b, and a lower flange portion 13e extending downward from the left end portion of the lower end wall portion 13c are provided. The fourth outer portion 14 includes a compression side wall portion 14a, an upper end wall portion 14b, a lower end wall portion 14c, an upper flange portion 14d, a lower flange portion 14e, and a third bead portion 14f. The configuration is substantially the same as the portion 11.

Next, the inner member 20 will be described.
As shown in FIGS. 2 to 5, the inner member 20 includes a first inner portion 21 (tensile side portion) constituting the left side portion of the front region 2 a and a second inner portion 22 constituting the left portion of the mount region 2 b. And a third inner portion 23 (compression side portion) constituting the left portion of the intermediate region 2c and a fourth inner portion 24 (tensile side portion) constituting the left portion of the rear region 2d. .

The first inner portion 21 includes a tensile side wall portion 21a along a plane substantially orthogonal to the left-right direction, an upper flange portion 21d extending upward from the upper end portion of the tensile side wall portion 21a, and a lower side from the lower end portion of the tensile side wall portion 21a. Is integrally provided with a lower flange portion 21e.
The second inner portion 22 includes a left wall portion 22a along a plane substantially orthogonal to the left-right direction, an upper flange portion 22d extending upward from the upper end portion of the left wall portion 22a, and a lower end portion of the left wall portion 22a. Are integrally provided with a lower flange portion 22e extending downward.

The third inner portion 24 includes a compression side wall portion 23a along a plane substantially orthogonal to the left-right direction, an upper flange portion 23d extending upward from the upper end portion of the left side wall portion 23a, and a lower side from the lower end portion of the left side wall portion 23a. Is integrally provided with a lower flange portion 23e. The compression side wall part 23a is provided with the 2nd bead part 23f dented in the main closed cross section C side. The second bead portion 23f is formed so as to be substantially orthogonal to the front-rear direction over the vertical direction of the compression side wall portion 23a.
The fourth inner portion 24 is integrally provided with a tensile side wall portion 24a, an upper flange portion 24d, and a lower flange portion 24e, and is configured in substantially the same manner as the first inner portion 21.
The main flange section 11d-14d is joined to the upper flange parts 21d-24d, and the lower flange parts 11e-14e are joined to the lower flange parts 21e-24e, so that a main closed section C extending in the front-rear direction is configured. .

Next, the first reinforcing member 30 will be described.
As shown in FIGS. 3 and 4, the first reinforcing member 30 is disposed in the main closed section C corresponding to the front region 2 a, and cooperates with the main closed section C so as to be adjacent to the upper and lower subordinates. A closed cross section c is formed.
As shown in FIGS. 3-6, the 1st reinforcement member 30 is formed in the elongate shape extended in the front-back direction by press-molding a single steel plate material, and the 1st-3rd compression side junction parts 31- 33, the 1st, 2nd tension | pulling side junction parts 34 and 35, and the 1st-4th partition wall parts 36-39 are comprised.

The 1st-3rd compression side junction parts 31-33 are formed along the surface substantially orthogonal to the left-right direction, and are joined to the upper stage part, middle stage part, and lower stage part of the compression side wall part 11a by welding, respectively. .
The 1st, 2nd tension | pulling side junction parts 34 and 35 are formed along the surface substantially orthogonal to the left-right direction, and are joined to the middle part of the tension | pulling side wall part 21a by welding, respectively. The first tension side joint 34 is disposed at a height position lower than the first compression side joint 31 and higher than the second compression side joint 32, and the second tension side joint 35 is the second compression side. It is disposed at a height position lower than the side joint portion 32 and higher than the third compression side joint portion 33.

The first partition wall portion 36 is formed to connect the lower end portion of the first compression side joint portion 31 and the upper end portion of the first tension side joint portion 34 so as to partition the main closed section C in the vertical direction.
The first partition wall portion 36 includes a first compression side partition portion 36a, a first tension side partition portion 36b, and a first connection portion 36c.
The first compression side partitioning part 36 a is formed so as to extend substantially horizontally from the lower end part of the first compression side joining part 31 to the left, and the first tension side partitioning part 36 b is formed of the first tension side joining part 34. It is formed to extend substantially horizontally from the upper end to the right.

  In the front end portion from the front end portion of the front region 2a to a predetermined rear position, the lateral width (left-right width) of the first compression side partition portion 36a is formed to be the same as the lateral width of the first tension side partition portion 36b (see FIG. 3), in the vicinity of the front end of the front region 2a from the predetermined rear position to the middle part, the lateral width of the first compression side partition 36a is gradually reduced and the lateral width of the first tension side partition 36b is gradually increased. The width of the first compression side partition 36a is half the width of the first tension side partition 36b in the latter half from the middle part to the rear end of the front region 2a. It is formed so that it may become a dimension (refer FIG. 4). As a result, the difference between the lateral width of the first compression side partitioning portion 36a and the lateral width of the first tension side partitioning portion 36b is substantially zero at the front end portion, and the lateral width of the first compression side partitioning portion 36a at the rear end portion. It is comprised so that the difference with the lateral width of the 1st tension | pulling side partition part 36b may become large. Further, in the vicinity of the front end, which is in the vicinity of the load input portion, the difference between the lateral width of the first compression side partitioning portion 36a and the lateral width of the first tension side partitioning portion 36b is linearly reduced toward the front side.

The first connecting portion 36c is formed in an inclined shape so as to move downward on the left side so as to connect the first compression side partition portion 36a and the first tension side partition portion 36b. The first connecting portion 36c is connected to the left end portion of the first compression side partition portion 36a via the compression side ridge line portion 36s, and is connected to the right end portion of the first tension side partition portion 36b via the tension side ridge line portion 36t. Yes.
As shown in FIGS. 3 and 4, the compression-side ridge line portion 36 s and the tension-side ridge line portion 36 t are located between the compression-side ridge line portion 36 s and the tension-side ridge line portion 36 t. And the distance between the compression-side ridge line portion 36s and the tension-side ridge line portion 36t is set to be substantially uniform from the front end to the rear end of the first reinforcing member 30. In consideration of the EA efficiency in the axial compression deformation, the distance between the compression side ridge line part 36s and the tension side ridge line part 36t is the left and right of the first compression side partition part 36a (first tension side partition part 36b) in the front end part. It is preferable to set the same dimension as the width.

The second partition wall portion 37 is formed to connect the upper end portion of the second compression side joint portion 32 and the lower end portion of the first tension side joint portion 34 so as to partition the main closed section C vertically.
The second partition wall portion 37 includes a second compression side partition portion 37a, a second tension side partition portion 37b, a second connection portion 37c, a compression side ridge line portion 37s, and a tension side ridge line portion 37t. . This 2nd partition wall part 37 is comprised so that it may become plane-symmetrical with the 1st partition wall part 36 with respect to a horizontal surface, and the compression side ridgeline part 37s and the tension side ridgeline part 37t are the compression side ridgeline part 36s and the tension side ridgeline. They are arranged so as to face each other directly below the portion 36t.

The third partition wall portion 38 is formed to connect the lower end portion of the second compression side joint portion 32 and the upper end portion of the second tension side joint portion 35 so as to partition the main closed section C vertically. The third partition wall portion 38 includes a third compression side partition portion 38a, a third tension side partition portion 38b, a third connection portion 38c, a compression side ridge line portion 38s, and a tension side ridge line portion 38t. The configuration is the same as that of the one partition wall portion 36.
The fourth partition wall portion 39 is formed to connect the upper end portion of the third compression side joint portion 33 and the lower end portion of the second tension side joint portion 35 so as to partition the main closed section C vertically. The fourth partition wall portion 39 includes a fourth compression side partition portion 39a, a fourth tension side partition portion 39b, a fourth connection portion 39c, a compression side ridge line portion 39s, and a tension side ridge line portion 39t. The two partition walls 37 are configured in the same manner.

Next, the second reinforcing member 40 will be described.
As shown in FIG. 7, the second reinforcing member 40 is disposed in the main closed section C corresponding to the midway region 2c, and cooperates with the main closed section C and is adjacent to the five sub closed sections c in the vertical direction. Is forming.
The 2nd reinforcement member 40 is formed in the elongate shape extended in the front-back direction by press-molding a single steel plate material, the 1st-3rd compression side junction parts 41-43, and the 1st, 2nd tension side It is comprised by the junction parts 44 and 45 and the 1st-4th partition wall parts 46-49.

The 1st-3rd compression side junction parts 41-43 are formed along the surface substantially orthogonal to the left-right direction, and are joined to the upper stage part of the compression side wall part 23a, the middle stage part, and the lower stage part by welding, respectively. .
The 1st, 2nd tension | pulling side junction parts 44 and 45 are formed along the surface substantially orthogonal to the left-right direction, and are joined to the middle part of the tension | pulling side wall part 13a by welding, respectively. The first tension side joint portion 44 is disposed at a height position lower than the first compression side joint portion 41 and higher than the second compression side joint portion 42, and the second tension side joint portion 45 is second compressed. It is disposed at a height position lower than the side joint portion 42 and higher than the third compression side joint portion 43.

The first partition wall portion 46 is formed to connect the lower end portion of the first compression side joint portion 41 and the upper end portion of the first tension side joint portion 44 so as to partition the main closed section C vertically. The first partition wall section 46 includes a first compression side partition section 46a, a first tension side partition section 46b, and a first connection section 46c.
The first compression side partition portion 46 a is formed so as to extend substantially horizontally from the lower end portion of the first compression side joint portion 41, and the first tension side partition portion 46 b is formed of the first tension side joint portion 44. It is formed so as to extend substantially horizontally from the upper end to the left. The lateral width of the first compression side partition 46a is formed to be half the width of the first tension side partition 46b.

The first connecting portion 46c is formed in an inclined shape so as to move upward on the left side so as to connect the first compression side partitioning portion 46a and the first tension side partitioning portion 46b. The first connecting portion 46c is connected to the right end portion of the first compression side partition portion 46a via the compression side ridge line portion 46s, and is connected to the left end portion of the first tension side partition portion 46b via the tension side ridge line portion 46t. Yes.
The compression-side ridge line portion 46s and the tension-side ridge line portion 46t are set so that the neutral surface N of compression and tension at the time of load input is positioned between the compression-side ridge line portion 46s and the tension-side ridge line portion 46t. The interval between the side ridge line portion 46 s and the tension side ridge line portion 46 t is set to a substantially uniform interval from the front end to the rear end of the second reinforcing member 40.

The second partition wall portion 47 is formed to connect the upper end portion of the second compression side joint portion 42 and the lower end portion of the first tension side joint portion 44 so as to partition the main closed section C vertically.
The second partition wall portion 47 includes a second compression side partition portion 47a, a second tension side partition portion 47b, a second connection portion 47c, a compression side ridge line portion 47s, and a tension side ridge line portion 47t. . The second partition wall portion 47 is configured to be plane-symmetric with the first partition wall portion 46 with respect to the horizontal plane, and the compression side ridge line portion 47 s and the tension side ridge line portion 47 t are the compression side ridge line portion 46 s and the tension side ridge line. They are arranged so as to face each other directly below the portion 46t.

The third partition wall portion 48 is formed to connect the lower end portion of the second compression side joint portion 42 and the upper end portion of the second tension side joint portion 45 so as to partition the main closed section C vertically. The third partition wall portion 48 includes a third compression side partition portion 48a, a third tension side partition portion 48b, a third connection portion 48c, a compression side ridge line portion 48s, and a tension side ridge line portion 48t. The configuration is the same as that of the one partition wall 46. The fourth partition wall 49 is formed to connect the upper end portion of the third compression side joint portion 43 and the lower end portion of the second tension side joint portion 45 so as to partition the main closed section C vertically. . The fourth partition wall portion 49 includes a fourth compression side partition portion 49a, a fourth tension side partition portion 49b, a fourth connection portion 49c, a compression side ridge line portion 49s, and a tension side ridge line portion 49t. The two partition walls 47 are configured in the same manner.
The third reinforcing member 50 is configured in the same manner as the second reinforcing member 40 and is disposed on the rear side of the second reinforcing member 40 so as to be plane-symmetric with respect to a plane orthogonal to the left-right direction. Detailed description will be omitted.

Next, the mount rain 8 will be described.
As shown in FIGS. 1, 8, and 9, the mount rain 8 includes a pair of front and rear bolts (not shown) extending in the vertical direction, and a pair of front and rear nut portions 7 a that are screwed to the pair of bolts. Thus, the engine mount device 7 is supported on the upper end wall portion 12b.
The mount rain 8 is joined to a main body portion 61 having a substantially hat-shaped cross section, a front side node portion 62 which is joined to the front end portion of the main body portion 61 and divides the main closed cross section C into the front and rear, and a rear end portion of the main body portion 61. It has a rear side node 63 that partitions the closed section C forward and backward, and is formed in a rectangular parallelepiped shape with one surface opened to the left.

As shown in FIGS. 8 and 9, the main body 61 includes an upper flange portion 61c and a lower flange portion 61d extending upward and downward from the left end portions of the upper end wall portion 61a and the lower end wall portion 61b, respectively.
The pair of nut portions 7a is joined to the upper end wall portion 61a and the lower end wall portion 61b in a state of penetrating in the vertical direction. The upper flange portion 61c is triple-coupled by the upper flange portion 12d and the upper flange portion 22d, and the lower flange portion 61d is triple-coupled by the lower flange portion 12e and the lower flange portion 22e.

The front side node 62 is a plate-like plate 62a that transversely partitions the main closed section C along a plane orthogonal to the front-rear direction, and extends forward from the upper end of the plate 62a and joined to the upper end wall 11b. The upper flange portion 62b has a lower flange portion 62c that extends forward from the lower end of the plate portion 62a and is joined to the lower end wall portion 11c.
The plate part 62a is disposed in an opposing manner at the rear end of the first reinforcing member 30 with a slight gap (for example, 2 to 3 mm). Thereby, a load is transmitted from the 1st reinforcement member 30 to the plate part 62a by the 1st reinforcement member 30 and the plate part 62a contact | abutting at the time of a front collision.

The rear side node 63 has a plate-like plate part 63a that transversely partitions the main closed section C along a plane orthogonal to the front-rear direction, and extends rearward from the upper end of the plate part 63a and is joined to the upper end wall part 13b. The upper flange portion 63b and a lower flange portion 63c that extends forward from the lower end of the plate portion 63a and is joined to the lower end wall portion 12c.
The plate portion 63a is disposed on the front end of the second reinforcing member 40 so as to be opposed to each other with a slight gap (for example, 2 to 3 mm). Thereby, a load is transmitted from the plate part 63a to the 2nd reinforcement member 40 from which cross-sectional shape differs from the 1st reinforcement member 30 by contact | abutting the 2nd reinforcement member 40 and the plate part 63a at the time of a front collision.

As shown in FIG. 5, a plate member 65 is disposed between the second reinforcing member 40 and the third reinforcing member 50. The plate member 65 is configured to transversely partition the main closed section C along a plane perpendicular to the front-rear direction, and has an upper end portion extending forward and joined to the upper end wall portion 13b, and a lower end portion being a lower end wall portion. 14c.
The plate member 65 is disposed opposite to the rear end of the second reinforcing member 40 with a slight gap (for example, 2 to 3 mm), and at the front end of the third reinforcing member 50, the slight gap (for example, 2 to 3 mm). ). Thereby, since the 2nd reinforcement member 40 and the plate member 65 contact | abut at the time of a front collision, the 3rd reinforcement member 50 and the plate member 65 contact | abut, From the 2nd reinforcement member 40 to the 3rd reinforcement member 50 from which a cross-sectional shape differs. Load is transmitted efficiently.

Next, functions and effects of the vehicle frame structure of the present embodiment will be described.
The deformation behavior when the vehicle V receives a front impact load will be described with reference to FIGS.
As shown in FIG. 10, the front side frame 2 is provided with a plurality of points extending substantially linearly in the front-rear direction for convenience of explanation so that the positional relationship after deformation can be easily understood.
The first point P1 is the front end position of the front region 2a, the second point P2 is the formation position of the first bead portion 11f of the front region 2a, the third point P3 is the front end position of the mount region 2b, and the fourth point P4 is the mount region 2b. The rear end position, the fifth point P5 is the formation position of the second bead portion 23f in the midway region 2c, the sixth point P6 is the placement position of the plate member 65, and the seventh point P7 is the third bead portion of the rear region 2d. The formation positions of 14f are shown respectively.

When a load that is not absorbed by the axial compression deformation of the crash can 6 is applied from the front, the front side frame 2 positively generates compression deformation and bending deformation in the vehicle width direction to absorb impact energy.
As shown in FIG. 11, when the colliding body collides with the front side frame 2, a load along the axial center is input to the front end of the front region 2a.
The input load acts as an axial compression load on the first point P1.
In the front end portion of the front region 2a, the left and right widths of the first to fourth compression side partition portions 36a to 39a and the left and right widths of the first to fourth tension side partition portions 36b to 39b are formed to be equal to each other. By shortening the wavelength of the compression load and decreasing the amplitude, uniform axial compression deformation is generated in the front-rear (axial center) direction, and EA (Energy Absorption) efficiency in the axial compression deformation increases.
The load that is not absorbed by the axial compression deformation is transmitted to the second point P2 in the second half portion through the vicinity of the front end where the shapes of the first to fourth partition wall portions 36 to 39 change gradually.

Since the first bead portion 11f serving as a starting point of bending deformation is formed on the outer member 10 at the second point P2, the transmitted load acts as an outer bending load.
Since the compression-side ridge line portions 36s to 39s and the tension-side ridge line portions 36t to 39t are formed on the first to fourth partition wall portions 36 to 39, respectively, the strength of the first to fourth partition wall portions 36 to 39 is achieved by the reinforcing effect by the ridge lines. Increases the allowable load limit.
Further, the vertical interval between the tension side ridge line portions 36t, 37t (38t, 39t) is formed smaller than the vertical interval between the compression side ridge line portions 36s, 37s (38s, 39s), and the first to fourth tension side partition portions 36b- Since the lateral width of 39b is formed larger than the lateral widths of the first to fourth compression side partition portions 36a to 39a, as shown in FIG. 12, after the occurrence of buckling, the tension side ridge line portion 36t (38t) and When the tension side ridge line part 37t (39t) abuts, the partition wall parts 36 to 39 cooperate to constitute a truss structure on the tension side to suppress the collapse of the cross section.
As a result, the EA efficiency due to the bending deformation is increased in the latter half of the front region 2a.

In the mount region 2b, the load input from the front region 2a is transmitted to the intermediate region 2c using the structure of the mount rain 8 without being dispersed elsewhere.
When the plate-like plate portion 62a that can be contacted over the entire rear end region of the first reinforcing member 30 contacts, a load that is not absorbed by the front region 2a is transmitted to the third point P3.
Since the mount rain 8 is highly rigid, the plate-like plate portion 63a that can be contacted over the entire front end of the second reinforcing member 40 comes into contact with the load, so that the load input to the mount rain 8 from the fourth point P4. It is efficiently transmitted to the second reinforcing member 40.

At the fifth point P5, since the second bead portion 23f serving as a starting point for bending deformation is formed on the inner member 20, the transmitted load acts as an internal bending load.
In the intermediate region 2c, the strength of the first to fourth partition wall portions 46 to 49 is increased by the reinforcing effect of the compression side ridge line portions 46s to 49s and the tension side ridge line portions 46t to 49t. A truss structure in which 46t (48t) and the pulling-side ridge line portion 47t (49t) are brought into contact with each other is configured to suppress cross-sectional collapse.
Thereby, the EA efficiency by bending deformation is increased.

Since the plate member 65 abuts over the entire rear end region of the second reinforcing member 40 and the plate member 65 abuts over the entire front end region of the third reinforcing member 50, a load that is not absorbed in the intermediate region 2c is generated. It is transmitted to the rear region 2d via 6 points P6.
Since the third bead portion 14f serving as a starting point of bending deformation is formed on the outer member 10 at the seventh point P7, the transmitted load acts as an outer bending load.
In the rear region 2d, the EA efficiency due to bending deformation is increased by the same action as the latter half of the front region 2a.

According to the vehicle frame structure, the EA efficiency in bending deformation and the EA efficiency in axial compression deformation can be improved by the single first reinforcing member 30.
That is, the vehicle frame structure includes the first and second horizontal partition walls 36 and 37 that form a plurality of sub-closed cross-sections c adjacent in the vertical direction in the main closed cross-section C. The allowable limit load can be increased by adjusting the aspect ratio of c to 1 or less, and this allowable limit load can be maintained for a certain stroke. The vertical interval between the compression side end portions (tensile side ridge portions 36t, 37t) of the first and second tension side partition portions 36b, 37b is the vertical interval between the tension side end portions of the first and second compression side partition portions 36a, 37a. Since it is formed smaller than (compression side ridge line parts 36s, 37s), the truss shape is formed by the contact of the compression side end parts of the first and second tension side partition parts 36b, 37b supported by the tension side wall part 21a. It can form and can suppress cross-sectional collapse accompanying bending deformation.
The difference between the lateral width of the first and second compression side partitioning portions 36a and 37a at the front end portion of the front region 2a and the lateral width of the first and second tension side partitioning portions 36b and 37b is the first half portion of the front region 2a. , Because it is formed to be smaller than the difference between the lateral width of the second compression side partitioning portions 36a and 37a and the lateral width of the first and second tension side partitioning portions 36b and 37b, The length can be shortened, and the wavelength of the axial compression load can be shortened and the amplitude can be decreased.

  In the vicinity of the front end of the front region 2a, the difference between the lateral width of the first and second compression side partition portions 36a and 37a and the lateral width of the first and second tension side partition portions 36b and 37b is reduced toward the front side. Therefore, the load that is not absorbed by the axial compression deformation can be continuously transmitted to the bending deformation portion, and the load can be efficiently absorbed at the bending deformation portion.

  In the front end portion of the front region 2a, the lateral width of the first and second compression side partitioning portions 36a and 37a and the lateral width of the first and second tension side partitioning portions 36b and 37b are formed in the same dimension, so that they are orthogonal to the front-rear direction. The length of one side of the cross section to be reduced can be minimized, and the EA efficiency in axial compression deformation can be increased.

  The neutral surface N of compression and tension at the time of load input is the tension side end portions of the first and second compression side partition portions 36a and 37a and the compression side end portions of the first and second tension side partition portions 36b and 37b. Therefore, while suppressing out-of-plane deformation, the truss shape is reliably formed by the contact of the compression side end portions of the first and second tension side partition portions 36b and 37b supported by the tension side wall portion 21a. can do.

Next, a modified example in which the embodiment is partially changed will be described.
1) In the above embodiment, an example of a front side frame has been described. However, a rear side frame, a suspension cross member, a bumper beam, a center pillar, an impact bar, or the like may be used for at least a vehicle frame on which a compressive load and a tensile load act. Any of them can be applied.

2] In the above embodiment, an example of four partition walls has been described from the viewpoint of EA efficiency, but the effect of the present invention can be achieved by providing at least two partition walls. Moreover, you may employ | adopt five or more partition walls from a design viewpoint.

3) In the embodiment described above, an example of a vehicle frame in which two outer bending deformation portions and one inner bending deformation portion are formed, and reinforcing members are provided in all of the deformation portions has been described. Only the reinforcing member that performs the deformation and bending deformation at the same time may be provided, and the reinforcing member dedicated to bending deformation may be omitted. Further, one outer fold deformation portion or one inner fold deformation portion may be formed in the vehicle frame.

4) In the above embodiment, the example has been described in which the difference between the lateral width of the first and second compression-side partition portions and the lateral width of the first and second tension-side partition portions is substantially zero at the front end portion of the front region. Depending on the design requirements, a difference in the range in which the wavelength of the axial compression load can be shortened and the amplitude can be reduced may be formed.
Also, in the latter half of the front region, the example has been described in which the width of the first and second compression side partitions is set to half the width of the first and second tension side partitions, but at least on the tension side The partition wall portion only needs to be configured, and the width ratio of the partition portion can be arbitrarily set based on the rigidity and shape of each partition wall portion.

5] In addition, those skilled in the art can implement the present invention with various modifications added without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

V Vehicle C Main closed cross section c Sub closed cross section N Neutral surface 2 Front side frame 11 First outer portion 11a Compression side wall portion 21 First inner portion 21a Tension side wall portion 30 First reinforcing member 36 First partition wall portion 36a First Compression side partition part 36b First tension side partition part 36s Compression side ridge line part 36t Tensile side ridge line part 37 Second partition wall part 37a Second compression side partition part 37b Second tension side partition part 37s Compression side ridge line part 37t Tensile side ridge line Part

Claims (4)

A compression side portion including a longitudinal compression side wall portion on which a compressive load acts and a longitudinal side wall portion including a vertical tension side wall portion on which a tensile load acts and which is orthogonal to the longitudinal direction in cooperation with the compression side portion are substantially rectangular. In a vehicle frame comprising: a tension side portion that forms a main closed cross section of a shape; and a reinforcing member that forms a plurality of sub closed cross sections adjacent in the vertical direction in cooperation with the main closed cross section.
The reinforcing member is a first partition wall portion that connects the compression side wall portion and the tension side wall portion to partition the main closed section vertically, and includes a first compression side partition portion extending from the compression side wall portion to the tension side. A first partition wall portion having a first tension side partition portion extending from the tension side wall portion to the compression side; and the compression side wall portion and the tension side wall portion are connected to each other at a position below the first partition wall portion to A second partition wall part that partitions the closed section up and down, and has a second compression side partition part extending from the compression side wall part to the tension side and a second tension side partition part extending from the tension side wall part to the compression side. Two partition walls,
The vertical interval between the compression side end portions of the first and second compression side partition portions is formed smaller than the vertical interval between the tension side end portions of the first and second compression side partition portions,
When a load is input to the vehicle frame from the longitudinal direction, the difference between the lateral width of the first and second compression side partition portions of the load input side portion and the lateral width of the first and second tension side partition portions is the load. It is smaller than the difference between the lateral width of the first and second compression side partitioning portions and the lateral width of the first and second tension side partitioning portions on the side opposite to the load input portion with respect to the load input side portion. A vehicle frame characterized by being formed as described above.   In the vicinity of the load input portion, the difference between the lateral width of the first and second compression side partition portions and the lateral width of the first and second tension side partition portions is reduced toward the load input portion side. The vehicle frame according to claim 1.   The said load input part WHEREIN: The lateral width of the said 1st, 2nd compression side partition part and the lateral width of the 1st, 2nd tension side partition part were formed in the same dimension, The Claim 1 or 2 characterized by the above-mentioned. Vehicle frame.   The neutral surface of compression and tension at the time of load input is located between the tension side end of the first and second compression side partitions and the compression side end of the first and second tension side partitions. The vehicle frame according to any one of claims 1 to 3, wherein: