JP2015020673A - Vehicle body structure of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear side frame excellent in impact absorption performance in an axial line direction while being low in cost.SOLUTION: In a rear side frame 14, a steel plate 14' is folded into one direction from one end p1 side toward the other end p2 side at a first corner a1, a second corner a2 and a third corner a3 in this order, also folded into the other direction at a fourth corner a4, a fifth corner a5 and a sixth corner a6, and formed into a "8"-figure shape at a closed cross section by connecting one end p1 to the fourth corner a4, and connecting the other end p2 to the third corner a3. Therefore, a cross section shape of the rear side frame 14 becomes point-symmetric (two-time symmetric) with respect to an axial line L of rear side frame, and when a collision load in the direction of the axial line L is inputted, a fold and a bend caused by an eccentric load are hardly generated, the collapse of the rear side frame 14 in the axial line L is promoted, and thus impact absorption performance is further improved.

Description

  The present invention relates to a vehicle body structure for an automobile in which a rear side frame extending rearward from a rear end of a side sill disposed in a front-rear direction on a vehicle body side portion is formed by bending a single steel plate into a closed cross section.

  The rear half of the car's rear side frame is made of a light alloy extruded material with a “eye” -shaped cross section, and the front half of the rear side frame is cut into a “day” -shaped cross section. The configuration is known from Patent Document 1 below.

  Further, it is known from Patent Document 2 below that a bumper reinforcing member having a “8” cross section is formed by roll forming a steel plate.

JP 2010-184596 A Japanese Patent No. 3204635

  By the way, since what was described in the said patent document 1 made the rear side frame into the product made from a light alloy, although there existed a problem which can aim at weight reduction, the manufacturing cost increased. Moreover, since light alloys are highly rigid and have lower ductility than steel, it is necessary to increase the cross-section and length of the rear side frame in order to absorb collision energy, which makes it difficult to adopt in small cars. It was.

  Moreover, what was described in the said patent document 2 is, after comprising a square cross section by bending a rectangular steel plate 4 times 90 degree in the same direction toward the other end side from one end side, and welding to the said one end, The welded portion is further bent once in the same direction to divide the square section into two parts, and a flange with the other end bent 90 ° in the opposite direction is welded to the inner surface of the square section to form an “8” -shaped section. Yes. Therefore, one end of the steel plate is attached to the bent portion of the steel plate and welded, and the other end of the steel plate is welded with the flange overlapped with the flat portion of the steel plate, so that the “8” -shaped cross section has an asymmetric shape. turn into. As a result, when this bumper reinforcement member structure is applied to the rear side frame, if a collision load is input in the axial direction, the strength is unbalanced around the axial line, causing it to bend laterally and exhibiting sufficient shock absorbing performance. It may not be possible.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a rear side frame that is low in cost and excellent in shock absorption performance in the axial direction.

  To achieve the above object, according to the first aspect of the present invention, a rear side frame extending rearward from the rear end of a side sill disposed in the front-rear direction on the side of the vehicle body is bent a plurality of times on a single steel plate. A vehicle body structure of an automobile configured in a closed cross section, wherein the rear side frame is unidirectional at a first corner, a second corner, and a third corner in order from the one end side to the other end side of the steel plate. And bending in the other direction at the fourth corner, the fifth corner and the sixth corner, connecting the one end to the fourth corner and connecting the other end to the third corner, An automobile body structure is proposed which is characterized by an “8” -shaped closed section.

  According to the invention described in claim 2, in addition to the structure of claim 1, the rear side frame is manufactured by bending the steel plate by roll forming and welding the one end and the other end. A vehicle body structure characterized by this is proposed.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the front end of the pair of left and right rear side frames is connected by a cross member extending in the vehicle width direction, and the rear side frame A vehicle body structure is proposed in which the cross member is connected by a brace member to form a triangular frame portion, and a panel is connected to the frame portion to close it.

  According to a fourth aspect of the present invention, in addition to the configuration of any one of the first to third aspects, the rear end of the side sill and the front end of the rear side frame are moved from the front lower side to the rear upper side. A vehicle body structure for an automobile is proposed, which is connected by a curved kick-up portion and a lower end of a frame member hanging from a roof side rail is connected to the rear portion of the kick-up portion.

  According to the invention described in claim 5, in addition to the configuration of claim 4, the frame member is a C pillar whose middle portion in the vertical direction bends backward, and rearward from the middle portion in the vertical direction of the C pillar. A vehicle body structure is proposed in which a horizontal member extending in the vertical direction is connected to a vertical middle portion of a D pillar positioned behind the C pillar, and the horizontal member and the rear side frame are connected by a rear wheel house. The

  According to the invention described in claim 6, in addition to the configuration of claim 5, the connecting portion of the C pillar and the horizontal member, and the connecting portion of the kick-up portion and the rear side frame are separated by a branch frame. A vehicle body structure characterized by connection is proposed.

  The second cross member 20 of the embodiment corresponds to the cross member of the present invention, the C pillar 26 of the embodiment corresponds to the frame member of the present invention, and the rear floor panel 48 of the embodiment is the panel of the present invention. Corresponding to

  According to the configuration of the first aspect, the rear side frame extending rearward from the rear end of the side sill disposed in the front-rear direction on the side of the vehicle body is configured to have a closed cross section by bending one steel plate. The rear side frame bends the steel plate in one direction in order from the one end side to the other end side at the first corner, the second corner, and the third corner, and the fourth corner, the fifth corner, and the sixth corner. The other side is bent in the other direction, and the one end is connected to the fourth corner and the other end is connected to the third corner, thereby forming a “8” -shaped closed section. Becomes point symmetric (2-fold symmetry) with respect to the axis, and when the collision load in the axial direction is input, bending due to the eccentric load is less likely to occur, so that the axial collapse of the rear side frame is promoted and the shock absorption performance is improved. Further improvement. In addition, when a collision load in a direction inclined with respect to the axis is input and a lateral load is generated, the direction of the lateral load is a direction parallel to the partition wall that divides the “8” -shaped closed section into two. Even if there is an orthogonal direction, the partition wall portion acts so as to maintain the cross-sectional shape of the rear side frame, so that the rear side frame is easily crushed in the axial direction, and the shock absorbing performance is further improved.

  According to the configuration of claim 2, since the rear side frame is manufactured by bending a steel plate by roll forming and welding one end and the other end, compared with a rear side frame configured by a light alloy extruded material. Low cost and excellent shock absorption performance.

  According to the third aspect of the present invention, the front ends of the pair of left and right rear side frames are connected by the cross member extending in the vehicle width direction, and the rear side frame and the cross member are connected by the brace member to connect the triangular frame portion. Since the panel is connected to the frame and closed, when the collision load of the rear collision is input to the rear side frame, the rear side frame is difficult to fall down in the vehicle width direction and the axial direction can be crushed, and the shock absorption performance Further improvement.

  Further, according to the configuration of claim 4, since the rear end of the side sill and the front end of the rear side frame are connected by the kick-up portion that curves from the front lower side to the rear upper side, when the collision load of the rear collision is input to the rear side frame, Although the rear side frame tends to bend upward with respect to the rear end of the side sill, the lower end of the frame member that hangs down from the roof side rail is connected to the rear of the kick-up portion, so that the rear side frame is bent upward by the frame member. And the rear side frame can be crushed in the axial direction.

  According to the fifth aspect of the present invention, the frame member is a C pillar whose upper and lower intermediate portions are bent rearward, and a horizontal member extending rearward from the upper and lower intermediate portion of the C pillar is located behind the C pillar. Since the horizontal member and the rear side frame are connected by the rear wheel house by connecting to the middle part of the pillar in the vertical direction, the horizontal member further prevents the rear side frame from being bent more reliably by suppressing the backward bending of the C pillar. Can be suppressed.

  According to the sixth aspect of the present invention, since the connecting portion of the C pillar and the horizontal member, and the connecting portion of the kick-up portion and the rear side frame are connected by the branch frame, the rear frame is further bent upward by the branch frame. It can be surely suppressed.

The perspective view of the vehicle body frame of a motor vehicle. FIG. FIG. 3 is a three-direction arrow view of FIG. 1. FIG. 4 is a four-direction arrow view of FIG. 3. FIG. 5 is a view in the direction of arrows 5 in FIG. 3. FIG. 6 is an enlarged sectional view taken along line 6-6 in FIG. FIG. 7 is an enlarged view of part 7 of FIG. 2. FIG. 8 is a cross-sectional view taken along line 8A-8A and 8B-8B in FIG. The disassembled perspective view of the periphery of a kick-up part. Explanatory drawing of the absorption characteristic of the collision load of a rear side frame.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the present specification, the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction are defined with reference to an occupant seated in the driver's seat.

  As shown in FIGS. 1 and 2, the vehicle body frame is connected to a pair of left and right side sills 13 and 13 disposed in the front-rear direction on the side of the vehicle body, and to the rear ends of the left and right side sills 13 and 13 to the rear. A pair of left and right rear side frames 14, 14 are provided. The rear ends of the left and right side sills 13 and 13 are connected by a first cross member 19 extending in the vehicle width direction, and the front ends of the left and right rear side frames 14 and 14 are connected by a second cross member 20 extending in the vehicle width direction. The rear ends of the left and right rear side frames 14, 14 are connected by a third cross member 21 extending in the vehicle width direction. A pair of left and right C pillars (rear pillars) 26, 26 stand up from the rear ends of the left and right side sills 13, 13, and a pair of left and right D pillars 27, 27 stand up from the rear ends of the left and right rear side frames 14, 14.

  A first roof arch 36 (see FIGS. 4 and 5) extending in the vehicle width direction is connected between the middle part in the front-rear direction of the pair of left and right roof side rails 33, 33 and the upper end of the left and right C pillars 26, 26. The rear ends of the left and right roof side rails 33, 33 and the upper ends of the left and right D pillars 27, 27 are connected by a second roof arch 37 extending in the vehicle width direction. Rear wheel houses 38L and 38R stand up from the left and right rear side frames 14 and 14, respectively, and the outer sides in the vehicle width direction of the rear wheel houses 38L and 38R are covered with rear fender panels 39L and 39R, respectively.

  As is clear from FIG. 6A, the rear side frame 14 is formed by bending one rectangular steel plate 14 'into a section "8" shape or a section "day" shape by roll forming. The cross-sectional shape will be described in detail. The first side s1, the first corner part a1, the second side s2, the second corner part a2, the third side s3 with the steel plate 14 'facing from the one end p1 side to the other end p2 side. The third corner a3 and the fourth side s4 are bent three times in the same direction in the order of 90 °, and then the fourth corner a4, the fifth side s5, the fifth corner a5, the sixth side s6, The hexagonal portion a6 and the seventh side s7 are bent three times in the reverse direction in the order of 90 °, and one end p1 is welded to the fourth corner portion a4 and the other end p2 is welded to the third corner portion a3. . The first side s1 and the fifth side s5 that are connected in a straight line and the third side s3 and the seventh side s7 that are connected in a straight line have the same length and are parallel to each other, and the second side s2 and the fourth side s4 and the sixth side s6 have the same length and are parallel to each other. Therefore, the cross-sectional shape of the rear side frame 14 is point symmetric (two-fold symmetric) with respect to the axis L. In the present embodiment, the rear side frame 14 is arranged such that the second side s2, the fourth side s4, and the sixth side s6 are directed in the vertical direction.

  As shown in FIG. 6 (B), the rear side frame 14 is in a state where the one shown in FIG. 6 (A) is laid down by 90 °, that is, the second side s2, the fourth side s4, and the sixth side s6 are in a horizontal posture. Can be arranged as follows. The fourth side s4 in FIGS. 6A and 6B is a partition wall that connects a pair of faces facing each other toward the inside of the rectangular cross section of the rear side frame 14.

  As shown in FIGS. 7 to 9, the side sill 13 is configured to have a closed cross-section by connecting the side sill inner 13 </ b> A and the side sill outer 13 </ b> B. It is connected with. The front end of the rear side frame 14 is biased upward and inward in the vehicle width direction with respect to the rear end of the side sill 13, and the kick-up portion 41 is a first member 41 </ b> A having a “U” -shaped cross section located on the inner side in the vehicle width direction. And a second member 41B having a “U” -shaped cross section located at the front part in the vehicle width direction outer side and a plate-like third member 41C located at the rear rear part in the vehicle width direction are combined to form a closed cross section. .

  The outer end in the vehicle width direction of the first cross member 19 is connected to the first member 41A of the kick-up portion 41 via an iron casting joint 42 that is an iron casting member. The iron casting joint 42 is integrally provided with a suspension arm support portion 42a that supports the front end of the suspension arm 43 of the torsion beam suspension and a cross member support portion 42b that supports the outer end of the first cross member 19 in the vehicle width direction. The suspension arm support portion 42a includes a vertical wall a, a horizontal wall b, a vertical wall c, and a horizontal wall d that are continuous in two steps.

  The extension wall e extends rearward and downward from the rear end of the vertical wall c. As a result, the suspension arm support portion 42a has a “U” shape opened downward by the vertical wall a, the horizontal wall b, and the extension wall e. A bolt hole f is formed in the vertical wall a where the cross section is formed, and a nut g facing the bolt hole f is welded to the inner surface in the vehicle width direction of the extension wall e. In a state where the rubber bush joint 43a (see FIG. 8) at the front end of the suspension arm 43 is fitted to the letter-shaped cross section, the bolt hole f of the vertical wall a and the bolt 44 penetrating the rubber bush joint 43a are attached to the extension wall e. By screwing onto the nut g, the suspension arm 43 is supported by the suspension arm support portion 42a so as to be swingable up and down.

  The cross member support portion 42b includes a plate-like cross member support wall h extending in a plate shape inward in the vehicle width direction from the vertical wall c and the horizontal wall d of the suspension arm support portion 42a. The cross member support wall h and the vertical wall are connected by three reinforcing ribs i extending in the vehicle width direction. A bracket 45 is connected to the front surface of the cross member support wall h and the inner surface in the vehicle width direction of the first member 41 </ b> A, and the first cross member 19 has a closed cross section formed between the cross member support wall h and the bracket 45. The outer ends in the vehicle width direction are fitted and welded. The first cross member 19 includes a concave portion 19a extending in the vehicle width direction, and the surface of the first cross member 19 facing the vehicle compartment is recessed rearward and downward due to the concave portion 19a.

  Then, an L-shaped cross-sectional portion formed of the horizontal wall b and the vertical wall c of the suspension arm support portion 42a of the iron casting joint 42 is welded to the lower wall 41a of the first member 42A of the kick-up portion 41 and the side wall 41b on the inner side in the vehicle width direction. As a result, the iron casting joint 42 is connected to the kick-up portion 41.

  As shown in FIGS. 3 to 5 and FIG. 7, the second cross member is arranged between the rear portions of the first members 41 </ b> A and 41 </ b> A of the left and right kick-up portions 41 and 41 in parallel with the rear portion of the first cross member 19. 20 is connected. The rear surface of the first cross member 19 and the front surface of the second cross member 20 are connected by a pair of left and right connecting members 46, 46 extending in the front-rear direction, and the second cross member 20 corresponding to the rear end position of the connecting members 46, 46 is connected. The rear surfaces are obliquely connected to the inner surfaces in the vehicle width direction of the left and right rear side frames 14 and 14 by a pair of left and right bracing members 47 and 47. The lower surfaces of the first cross member 19, the second cross member 20, the left and right kick-up portions 41 and 41, and the left and right rear side frames 14 and 14 are connected by a rear floor panel 48 having a spare tire storage recess 48a. Accordingly, the triangular frame portion 49 surrounded by the second cross member 20, the rear side frame 14 and the bracing member 47 is closed and reinforced by the rear floor panel 48.

  The lower end of the C pillar 26 is connected to the upper surface of the kick-up portion 41 where the outer end in the vehicle width direction of the first cross member 19 is continuous. The C pillar 26 is arranged along the rear edge of the door opening of the rear door, and its middle portion in the vertical direction is bent backward so as to be bent in a “<” shape and extends rearward from the bent portion. The rear end of the horizontal member 50 is connected to the middle portion of the D pillar 27 in the vertical direction. A branch frame 51 extends downward from a bent portion of the C pillar 26, that is, a connection portion with the horizontal member 50, and the lower end of the branch frame 51 is connected to the upper surface of the rear end of the kick-up portion 41.

  The lower ends of the left and right rear wheel houses 38L, 38R obtained by press-working the steel plates are connected to the outer surfaces in the vehicle width direction of the left and right rear side frames 14, 14. The shape of the left rear wheel house 38L is different from the shape of the right rear wheel house 38R. That is, a damper support wall 38a that supports the upper end of a damper (not shown) of the suspension device is formed substantially horizontally in the vertical middle portion of the left rear wheel house 38L, and the rear wheel house 38L is formed of a damper support wall 38a. It extends upward while being gently curved from the outer end in the vehicle width direction and is connected to the horizontal member 50. A raised portion 38b that extends in the vertical direction and protrudes inward in the vehicle width direction is formed at a position adjacent to the front of the damper support wall 38a.

  A rear fender panel 39L, which is curved outwardly in the vehicle width direction by pressing a steel plate, is connected to the outer surface in the vehicle width direction of the rear wheel house 38L. A circular projecting portion 39a (see FIG. 4) surrounding a fuel filler opening (not shown) of the fuel tank is formed on the upper portion of the rear fender panel 39L, and the projecting portion 39a faces the raised portion 38b of the rear wheel house 38L. .

  The upper portion of the right rear wheel house 38R is interrupted in the vicinity of the damper support wall 38a, and the right rear wheel house 38R does not include a raised portion 38b corresponding to the raised portion 38b of the left rear wheel house 38L. An upper and lower frame 54 extending upward from the upper end of the right rear wheel house 38R is connected to the horizontal member 50.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  When the vehicle collides rearward and a forward collision load is input to the rear end of the rear side frame 14, the collision load can be efficiently absorbed if the rear side frame 14 sequentially collapses from the rear end side toward the front end side. it can. When a collision load in the direction of the axis L (see FIG. 6) is input to the rear side frame 14, the rear side frame 14 of the present embodiment includes a partition wall that connects a pair of surfaces facing toward the inside. Therefore, the rear side frame 14 can be prevented from being bent by a collision load as much as possible, and the rear side frame 14 can be crushed over a long stroke to efficiently absorb the collision load.

  FIG. 10 shows the anti-collision performance when the collision load is input with an angle α (see FIG. 10A) in the left-right direction with respect to the axis L, and CASE 1 is shown in FIG. As shown in FIG. 6B, the rear side frame 14 is arranged so that the fourth side s4 is vertical. As shown in FIG. 6B, CASE2 is arranged so that the fourth side s4 is horizontal. This corresponds to the case where the rear side frame 14 is arranged.

  FIG. 10B shows the relationship between the crushing stroke of the rear side frame 14 (distance from the rear end of the rear side frame 14) and the load. In the region where the stroke is in the initial stage, the arrangement of FIG. The load when α = 12 ° in CASE 1) and the load when α = 12 ° in the arrangement (CASE 2) of FIG. 6B are smaller than the load when α = 0 ° (CASE 1). However, in the strokes after that, the magnitude of the load is almost the same in any of CASE 0, CASE 1 and CASE 2, and it can be seen that stable shock absorbing performance is exhibited regardless of the input direction of the load. .

  FIG. 10C shows how the average load of CASE 0, CASE 1 and CASE 2 changes according to the input angle α of the collision load. The average load of CASE 1 (α = 2 ° to 14 °) and CASE 2 (α = 2 ° to 12 °) is almost the same as the average load of CASE 0 (α = 0 °), and CASE 2 (α = 14 °) It can be seen that the average load decreases for the first time.

  As described above, when the input angle α of the load is α = 12 ° or less, the shock absorbing performance which is almost inferior to that of α = 0 ° can be exhibited because of the following reason. Conceivable. That is, in the case of CASE 1 shown in FIG. 10A, the fourth side s4 constituting the partition wall of the rear side frame 14 opposes the load F inclined by the angle α with respect to the axis L and maintains the sectional shape. As a result, the out-of-plane deformation of the other first side s1, third side s3, fifth side s5, and seventh side s7 is suppressed, and the second side s2 and the sixth side s6 are also deformed out-of-plane. It becomes difficult. As a result, it is considered that the rear side frame 14 is prevented from being bent with respect to the axis L, and the crushing of the rear side frame 14 in the axis L direction is promoted.

  In the case of CASE 2 shown in FIG. 10B, the fourth side s4 constituting the partition wall of the rear side frame 14 is opposed to the load F inclined by the angle α with respect to the axis L and maintains the cross-sectional shape. Thus, the out-of-plane deformation of the other first side s1, third side s3, fifth side s5, and seventh side s7 is directly suppressed, and the second side s2 and the sixth side s6 are also deformed out-of-plane due to the influence. It becomes difficult. As a result, it is considered that the rear side frame 14 is prevented from being bent with respect to the axis L, and the crushing of the rear side frame 14 in the axis L direction is promoted. In particular, in CASE 2, since the fourth side s4 constituting the partition wall of the rear side frame 14 is parallel to the direction of the lateral load F, the out-of-plane deformation of the fourth side s4 is further effectively suppressed.

  In addition, the rear side frame 14 of the present embodiment is manufactured by bending the steel plate 14 'by roll forming and welding one end p1 and the other end p2 by welding w1 and w2. Therefore, the rear side frame constituted by a light alloy extruded material. Compared to, it has excellent shock absorption performance at low cost.

  Also, the front ends of the pair of left and right rear side frames 14, 14 are connected by a second cross member 20 extending in the vehicle width direction, and the rear side frames 14, 14 and the second cross member 20 are connected by bracing members 47, 47 to form a triangular shape. Frame portions 49, 49 (see FIG. 7) and the frame portions 49, 49 are closed by the rear floor panel 48. Therefore, when the collision load of the rear collision is input to the rear side frames 14, 14, the rear side frames 14, 14 Becomes difficult to fall down in the vehicle width direction and can be crushed in the direction of the axis L, and the impact absorbing performance is further improved.

  By the way, since the front end of the rear side frame 14 is displaced upward with respect to the rear end of the side sill 13, the rear end of the side sill 13 and the front end of the rear side frame 14 are connected when a collision load of a rear collision is input to the rear side frame 14. There is a possibility that a bending moment acts on the bent kick-up portion 41 to be deformed so that the rear end of the rear side frame 14 is lifted upward. As described above, when the rear end of the rear side frame 14 is lifted upward, the crushing in the direction of the axis L becomes difficult, and there is a possibility that the shock absorbing performance is significantly lowered.

  However, according to the present embodiment, since the lower end of the C pillar 26 hanging from the roof side rail 33 is connected to the rear portion of the kick-up portion 41, the C pillar 26 is stretched to prevent the rear side frame 14 from being bent upward. By doing so, the crushing of the rear side frame 14 in the direction of the axis L can be promoted.

  Further, a horizontal member 50 extending rearward from the vertical intermediate portion of the C pillar 26 is connected to the vertical intermediate portion of the D pillar 27, and the horizontal member 50 on the left side in the vehicle width direction and the rear side frame 14 are connected by a rear wheel house 38L. Since the raised portion 38b (see FIGS. 3 and 4) extending from the horizontal member 50 to the rear portion of the kick-up portion 41 is formed in the rear wheel house 38L, the intermediate portion in the vertical direction is bent backward in a “<” shape. The horizontal member 50 prevents the C pillar 26 from bending backward, so that the upward bending of the rear side frame 14 can be further reliably suppressed.

  At this time, the C pillar 26 is bent in a “<” shape at the bent portion along the rear edge of the rear door opening, and the front end of the horizontal member 50 is connected to the bent portion of the C pillar 26. The bending of the bent portion of the C pillar 26 can be prevented, and the upward tilt of the rear side frame 14 due to the collision load of the rear collision can be prevented while minimizing the cross section of the C pillar 26.

  Moreover, since the connecting portion of the C pillar 26 and the horizontal member 50 and the connecting portion of the kick-up portion 41 and the rear side frame 14 are connected by the branch frame 51, the rear side frame 14 is bent upward as the branch frame 51 is stretched. Furthermore, it can suppress reliably.

  The kick-up portion 41 connecting the side sill 13 and the rear side frame 14 includes a suspension arm support portion 42a that supports the suspension arm 43 and a cross member support portion 42b that supports the end of the first cross member 19 extending in the vehicle width direction. Therefore, the kick-up portion 41 is prevented from being bent and deformed so that the rear end of the rear side frame 14 is lifted by the collision load of the rear collision, and the rear side frame 14 is moved in the direction of the axis L. The first cross member 19 can be firmly connected to the kick-up portion 41 to increase the torsional rigidity of the vehicle body.

  In particular, the iron casting joint 42 includes reinforcing ribs i (see FIGS. 7 to 9) that connect the suspension arm support 42a and the cross member support 42b, so that the suspension arm support 42a and the cross are supported by the reinforcing rib i. The connection portion of the member support portion 42b can be reinforced to increase the support rigidity of the suspension arm 43.

  Further, the suspension arm support portion 42a has an L-shaped cross section (the horizontal wall b and the vertical wall c shown in FIG. 9) on the lower wall 41a of the first member 41A of the kick-up portion 41 and the side wall 41b on the inner side in the vehicle width direction. Since the connection is made (see FIG. 9), the kick-up portion 41 is effectively reinforced while reducing the weight of the iron casting joint 42 and reducing the weight, and the collision load of the rear collision is efficiently transferred from the rear side frame 14 to the side sill 13. Can communicate.

  Further, since the first cross member 19 having a hollow closed cross section is sandwiched between the cross member support portion 42b of the iron casting joint 42 and the bracket 45 connected thereto, the assembly property of the first cross member 19 to the iron casting joint 42 is improved. In addition to improvement, the torsional rigidity of the vehicle body can be increased by firmly connecting the first cross member 19 to the kick-up portion 41.

  Moreover, the left and right kick-up portions 41, 41 are connected to both ends in the vehicle width direction of the second cross member 20 behind the first cross member 19, and the first cross member 19 and the second cross member 20 extend in the front-rear direction. Since the second cross member 20 and the left and right rear side frames 14, 14 are connected obliquely via the left and right bracing members 47, 47, the side sills 13, 13 and the rear side frame 14, 14 to effectively reinforce the torsional rigidity of the vehicle body. Further, since the first cross member 19 is provided with a concave portion 19a (see FIG. 9) extending in the vehicle width direction on the front-upward surface, the concave portion 19a increases the rigidity of the first cross member 19.

  Since the left rear wheel house 38L includes a damper support wall 38a that extends in the horizontal direction and supports the upper end of the suspension damper, an upward load is applied to the damper support wall 38a from the suspension damper. However, since the rear wheel house 38L damper support wall 38a continues from the outer end in the vehicle width direction to the horizontal member 50 in a gently curved shape, the upward load input to the damper support wall 38a from the upper end of the suspension damper is gentle. It is efficiently transmitted to the horizontal member 50 via the curved rear wheel house 38L.

  Moreover, the rear fender panel 39L that covers the vehicle width direction outer side of the left rear wheel house 38L is provided with an annular protrusion 39a (see FIG. 4) surrounding the fuel supply port, and the protrusion 39a is provided on the rear wheel house 38L. Since it faces the upper end of the raised portion 38b, the upward load input from the suspension damper can be transmitted to the horizontal member 50 via both the rear wheel house 38L and the rear fender panel 39L.

  The upper end of the right rear wheel house 38R does not reach the position of the horizontal member 50, but the upper end of the rear wheel house 38R and the horizontal member 50 are connected by the reinforcing frame 52 (see FIGS. 3 and 5). An upward load input from the rear side frame 14 and an upward load input from the suspension damper to the damper support wall 38 a can be transmitted to the horizontal member 50 via the reinforcing frame 52.

  Further, the left and right bracing members 47, 47 (FIG. 3) are connected to the upper ends of the left and right C pillars 26, 26 and the center portion in the vehicle width direction of the second roof arch 37 connecting the upper ends of the left and right D pillars in the vehicle width direction. In this case, the upward load input from the suspension damper can be efficiently transmitted from the C pillars 26 and 26 to the roof side rails 33 and 33 and the second roof arch 37 to be absorbed. .

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, the rear side frame 14 is manufactured by roll forming, but the manufacturing method is arbitrary.

13 Side sill 14 Rear side frame 14 'Steel plate 20 Second cross member (cross member)
26 C pillar (frame member)
27 D pillar 33 Roof side rail 38L Rear wheel house 41 Kick-up part 47 Bracing member 48 Rear floor panel (panel)
49 Frame 50 Horizontal member 51 Branch frame a1 1st corner a2 2nd corner a3 3rd corner a4 4th corner a5 5th corner a6 6th corner p1 One end p2 The other end w1 Welding w2 Welding

Claims (6)

A vehicle body structure for an automobile in which a rear side frame (14) extending rearward from the rear end of a side sill (13) disposed in the front-rear direction on the side of the vehicle body is formed into a closed cross section by bending a plurality of steel plates (14 '). Because
The rear side frame (14) has a first corner (a1), a second corner (a2) and a third corner in order from the one end (p1) side to the other end (p2) side of the steel plate (14 '). The corner (a3) is bent in one direction, the fourth corner (a4), the fifth corner (a5) and the sixth corner (a6) are bent in the other direction, and the one end (p1) is bent in the fourth corner. A vehicle body structure characterized in that it is configured in an “8” -shaped closed section by connecting to the portion (a4) and connecting the other end (p2) to the third corner portion (a3). .   The rear side frame (14) is manufactured by bending the steel plate (14 ') by roll forming, and welding (w1, w2) the one end (p1) and the other end (p2). The vehicle body structure according to claim 1.   The front ends of the pair of left and right rear side frames (14) are connected by a cross member (20) extending in the vehicle width direction, and the rear side frame (14) and the cross member (20) are connected by a brace member (47). The vehicle body structure according to claim 1 or 2, wherein a triangular frame portion (49) is formed, and a panel (48) is connected to the frame portion (49) to be closed.   The rear end of the side sill (13) and the front end of the rear side frame (14) are connected by a kick-up portion (41) that curves from the front lower side to the rear upper side, and a roof side rail is attached to the rear portion of the kick-up portion (41). The vehicle body structure according to any one of claims 1 to 3, wherein a lower end of a frame member (26) hanging from (33) is connected.   The frame member (26) is a C pillar (26) whose upper and lower direction intermediate portion is bent backward, and a horizontal member (50) extending rearward from the upper and lower direction intermediate portion of the C pillar (26) is connected to the C pillar (26). The horizontal member (50) and the rear side frame (14) are connected to each other by a rear wheel house (38L). Item 5. A vehicle body structure according to Item 4.   The connecting portion of the C pillar (26) and the horizontal member (50) and the connecting portion of the kick-up portion (41) and the rear side frame (14) are connected by a branch frame (51). The vehicle body structure according to claim 5.

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