JP2007245875A - Vehicle rear part structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further enhance absorption property of collision energy by suitably controlling a buckling position in rear collision at a rear floor side member. <P>SOLUTION: The vehicle rear part structure has a reinforcement member 12 (reinforcement part) for suppressing buckling in a range from a rear end to a predetermined position at a front side of the vehicle on a bottom part 10J of the rear floor side member 10. Since the bottom 10J is more hardly deformed by the reinforcement member 12, when the vehicle is subjected to rear collision, high load is transmitted to the bottom part 10J. The rear floor side member 10 is buckled toward a lower side at a position near a front side of the vehicle where the high load is applied. The buckling position 10K can be suitably controlled by adjusting longitudinal length of the reinforcement member 12, and the absorption property of the collision energy can be further enhanced by buckling the rear floor side member 10 by high load. Further, the high load can be more certainly transmitted to a lower ridgeline 10G by providing an intermediate plate 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle rear structure.

A change part is provided in the rear part of the car to give a large difference in rigidity to the change part, and a bead is provided on the lower side of the rear floor side member, and the rear floor side member changes downward when the car receives input energy from the rear part. The structure to be made is disclosed (refer patent document 1).
Japanese Patent Laid-Open No. 6-199249

  However, in the configuration in which the rear floor side member is provided with a fragile bead as in the conventional example described above, the rigidity of the rear floor side member is reduced overall, so that the influence of the deformation of the rear part of the vehicle at the time of a rear collision is May extend to the front of the member.

  In view of the above-described facts, an object of the present invention is to appropriately control the buckling position of a rear floor side member at the time of a rear collision so as to further improve the absorption of collision energy.

  The invention of claim 1 is provided in a range from a rear end to a predetermined position on the front side of the vehicle at a rear floor side member extending in the vehicle front-rear direction on each of the left and right sides of the rear portion of the vehicle. And a reinforcing portion that suppresses buckling of the bottom portion within the range when the vehicle is subjected to a rear collision.

  In the vehicle rear structure according to claim 1, since the reinforcing portion is provided in a range from the rear end to a predetermined position on the vehicle front side at the bottom of the rear floor side member, even if a load is input from the rear of the vehicle, The bottom portion is not easily deformed, and more load is transmitted to the bottom portion. Since the reinforcing part is provided in a range from the rear end of the bottom part to a predetermined position on the front side of the vehicle, the high load transmitted to the bottom part acts on the front side of the front part of the reinforcing part in the vicinity of the front side of the vehicle. The side member buckles downward at a position near the vehicle front side. For this reason, the buckling position of the rear floor side member at the time of rear collision can be controlled appropriately by adjusting the longitudinal length of the reinforcing part, and the collision energy can be absorbed by buckling the rear floor side member with a high load. The sex can be increased.

  According to a second aspect of the present invention, in the vehicle rear portion structure according to the first aspect, a first lower flange extending downward from a rear end of the bottom portion of the rear floor side member and a rear side of the rear floor side member are fixed. An intermediate plate that overlaps the rear side of the first lower flange and has a lower load transmission portion that is reinforced at least in terms of bending rigidity in the vehicle longitudinal direction, and is fixed to the rear side of the intermediate plate and on the front side of the rear bumper reinforcement. And a rear bumper arm having a second lower flange that is fixed and overlaps a rear side of the lower load transmitting portion of the intermediate plate.

  In the vehicle rear structure according to the second aspect, the load input to the bumper reinforcement at the time of the rear collision of the vehicle is transmitted to the intermediate plate via the bumper arm, and further transmitted from the intermediate plate to the rear floor side member. Since the lower load transmission portion of the intermediate plate is reinforced at least with respect to the bending rigidity in the vehicle longitudinal direction, when the rear floor side member is initially deformed, more load is applied to the lower ridge line, that is, the bottom portion than the upper ridge line of the rear floor side member. Can be transmitted. Then, by applying a high load to the bottom portion, the rear floor side member can be buckled in the vicinity of the vehicle front side of the reinforcing portion at the bottom portion.

  As described above, according to the vehicle rear structure according to the first aspect of the present invention, the buckling position at the time of a rear collision in the rear floor side member can be appropriately controlled, and the absorption of collision energy can be further improved. The excellent effect of being able to be obtained is obtained.

  According to the vehicle rear portion structure of the second aspect, an excellent effect is obtained that the rear floor side member can be buckled in the vicinity of the vehicle front side of the reinforcing portion at the bottom.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the vehicle rear portion structure S according to the present embodiment includes a rear floor side member 10, a reinforcing member 12 that is an example of a reinforcing portion, an intermediate plate 14, and a rear bumper arm 16.

  In FIG. 2, the rear floor side member 10 is a strength member that extends in the vehicle front-rear direction on the left and right sides of the rear part of the vehicle, and is configured to have, for example, a reverse hat shape in cross section, respectively on the both sides in the vehicle width direction from the upper ridge line 10A. The extending flange portion 10B is joined to the lower surface of the rear floor panel 34 (FIG. 6). A bottom portion 10J is formed between the left and right lower ridge lines 10G in the rear floor side member 10. At the rear end of the rear floor side member 10, a left flange 10C extending leftward from the rear end as viewed from the rear of the vehicle, a right flange 10D extending rightward, and a first lower flange 10E extending downward are respectively extended. It is installed.

  The left flange 10C and the right flange 10D are formed with through holes 10H through which bolts 18 for fixing the intermediate plate 14 and the rear bumper arm 16 to the rear floor side member 10 are passed, and the left flange 10C and the right flange 10D on the front surface of the vehicle. A nut 20 is welded, for example, at a position corresponding to the through hole 10H.

  Similarly, the first lower flange 10E is formed with a through hole 10F through which a bolt 22 for fixing the intermediate plate 14 and the rear bumper arm 16 to the rear floor side member 10 is passed. A nut 24 is welded, for example, at a position corresponding to the through hole 10F. In order to increase the bending rigidity of the first lower flange 10E, for example, a rib may be provided between the vehicle front surface of the first lower flange 10E and the bottom surface of the rear floor side member 10 (not shown).

  In FIG. 2, the reinforcing member 12 is provided in a range from the rear end to a predetermined position on the front side of the vehicle at the bottom portion 10J of the rear floor side member 10, and the bottom portion 10J in the range is buckled when the vehicle collides rearward. It is a member which suppresses. Specifically, the reinforcing member 12 is a member formed in a U-shaped cross section corresponding to the inner dimension of the rear floor side member 10, for example, and is a range from the rear end of the bottom 10J to a predetermined position on the vehicle front side. Are joined to each other. Here, the predetermined position is the vicinity of the rear side of the buckling position 10K where buckling occurs at the time of a rear-end collision of the vehicle, and the front end 12A of the reinforcing member 12 is located at the predetermined position.

  The intermediate plate 14 is a plate-like member that is fixed to the rear side of the rear floor side member, and has a lower load transmission portion 14E that overlaps the rear side of the first lower flange 10E of the rear floor side member 10. The lower load transmission portion 14E is reinforced at least with respect to bending rigidity in the vehicle front-rear direction.

  Specifically, the lower load transmission portion 14E is formed in, for example, a trapezoid whose width gradually decreases downward, and flanges 14A are extended from both end edges toward the rear of the vehicle. The flange 14A increases the bending rigidity of the lower load transmission portion 14E in the vehicle front-rear direction. As shown in FIG. 1, in the vehicle rear structure S, the flange 14A extends upward from the lower end of the intermediate plate 14 to a position where it overlaps the left flange 10C and the right flange 10D of the rear floor side member 10 beyond the bottom 10J. It is extended.

  The upper part of the intermediate plate 14 is formed to have a width dimension equivalent to the width from the left end edge of the left flange 10C to the right end edge of the right flange 10D in the rear floor side member 10, and the left flange 10C and the right flange 10D are formed on the upper part. Two through-holes 14H corresponding to the through-holes 10H respectively formed are formed. A through hole 14F corresponding to the through hole 10F of the first lower flange 10E is formed in the lower load transmission portion 14E.

  As shown in FIG. 3, when the thickness of the intermediate plate 14 is relatively thin, an additional flange 14B for connecting the lower ends of the flange 14A may be provided. Further, the means for increasing the bending rigidity of the lower load transmission portion 14E is not limited to the flanges 14A and 14B, and as shown in FIG. 4, a plurality of beads 14C extending in the vehicle vertical direction are used as the lower load transmission portion 14E. The bending rigidity may be increased by forming the above. Furthermore, although the shape of the lower load transmission portion 14E is a trapezoid whose width gradually decreases downward, the shape of the lower load transmission portion 14E is not limited to this.

  The rear bumper arm 16 is a member that is fixed to the rear side of the intermediate plate 14 and is fixed to the front side of the rear bumper reinforcement 26, and has a second lower flange 16E that overlaps the rear side of the lower load transmitting portion 14E of the intermediate plate 14. The vehicle rear surface 16A is closed, and the front of the vehicle is formed in a box shape.

  At the front end of the rear bumper arm 16, a left flange 16C that extends leftward from the front end, a right flange 16D that also extends rightward, a second lower flange 16E that also extends downward, and an upper portion that also extends upward. A flange 16B is extended.

  The left flange 16C is formed with a through hole 16H corresponding to the through hole 10H of the left flange 10C of the rear floor side member 10 and the left through hole 14H of the intermediate plate 14 when viewed from the rear of the vehicle. The right flange 16D is formed with a through hole 16H corresponding to the through hole 10H of the right flange 10D of the rear floor side member 10 and the right through hole 14H of the intermediate plate 14 when viewed from the rear of the vehicle.

  On the vehicle rear surface 16A of the rear bumper arm 16, for example, two through holes 16G are formed in the vertical direction of the vehicle. Bolts 30 (FIG. 8) provided to protrude from the rear bumper reinforcement 26 to the front of the vehicle are connected to the through holes 16G. The rear bumper arm 16 and the rear bumper reinforcement 26 are fixed to each other by being fastened by a nut (not shown) from the rear surface side of the vehicle rear surface 16A.

  In FIG. 5, a rear bumper reinforcement 26 is a strength member disposed in the rear bumper cover 32 and extending in the vehicle width direction, and a hook 28 for traction or lashing is provided on the rear surface of the vehicle. The hook 28 is fastened to a nut 42 provided in the rear bumper reinforcement 26, for example. The height position of the hook 28 is equivalent to the height position of the reinforcing member 12, for example.

  As shown in FIG. 1, the rear bumper arm 16 and the intermediate plate 14 are assembled to the rear floor side member 10 by bolts 18 and 22 and nuts 20 and 24 (FIG. 2). Further, a rear floor panel 34 is joined on the left and right rear floor side members 10, and the center of the rear floor panel 34 sandwiched between the left and right rear floor side members 10 is, for example, the front side as shown in FIG. A recess 34A and a rear recess 34B are formed. For example, a fuel tank 36 is attached to the front concave portion 34A, and for example, a spare tire 38 is accommodated in the rear concave portion 34B.

  As shown in FIGS. 6 and 7, the buckling position 10K at the bottom 10J of the rear floor side member 10 is raised by raising the rear concave portion 34B of the rear floor panel 34 upward by buckling at the buckling position 10K. It is determined so that the front portion of the tire 38 can be rotated to lift upward. The buckling of the bottom portion 10J occurs in the vicinity of the front side of the front end 12A of the reinforcing member 12 where the reinforcement by the reinforcing member 12 ends, so that the position of the buckling position 10K is adjusted by adjusting the longitudinal length of the reinforcing member 12. It is possible to control appropriately.

  The rear floor side member 10 is not provided with a fragile portion (not shown) such as a bead, so that the rear floor side member 10 is not deformed early at the time of a rear collision.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. First, referring to FIGS. 6 and 7, an operation when the vehicle is subjected to a rear collision will be described. When the collision body 40 collides with the rear portion of the vehicle having the vehicle rear structure S at a relatively high speed, a load from the rear is input to the rear bumper reinforcement 26 via the rear bumper cover 32. This load is transmitted to the rear floor side member 10 via the rear bumper arm 16 and the intermediate plate 14, and mainly becomes an axial compression force for the rear floor side member 10.

  At this time, as shown in FIG. 2, the upper portion of the intermediate plate 14 is not reinforced by the flange 14A, and thus is relatively easily deformed. On the other hand, the lower load transmitting portion 14E reinforced by the flange 14A is relatively deformed. It is difficult, and in the initial stage of deformation, more load is transmitted to the lower ridge line 10G, that is, the bottom portion 10J than the upper ridge line 10A of the rear floor side member 10.

  In the vehicle rear structure S, the second lower flange 16E, the lower load transmitting portion 14E, and the first lower flange 10E are overlapped in the vehicle front-rear direction, and therefore, the fastening portion of the rear floor side member 10, the intermediate plate 14, and the rear bumper arm 16 Even if a downward bending moment acts on the bending deformation, bending deformation due to the bending moment can be suppressed. By suppressing this bending deformation, the axial compression force acting on the rear floor side member 10 can be increased.

  In FIG. 6, since the reinforcing member 12 is provided in the range from the rear end of the bottom 10J of the rear floor side member 10 to a predetermined position on the vehicle front side, even if a high load is transmitted by the bottom 10J, The bottom portion 10J within the predetermined range is difficult to be deformed, and the high load acts near the front side of the front end 12A of the reinforcing member 12 in the vehicle. Since the vehicle front side vicinity position is a boundary between the reinforced portion and the non-reinforcement portion in the bottom portion 10J, stress is easily concentrated, and the rear floor side member 10 is buckled downward at the vehicle front side vicinity position. . The position in the vicinity of the vehicle front side is a buckling position 10K. The upper ridge line 10A buckles after the lower ridge line 10G buckles.

  In FIG. 7, when the buckling of the rear floor side member 10 progresses, the vicinity of the buckling position 10K is deformed upward and the rear floor panel 34 joined on the rear floor side member 10 follows this, The rear concave portion 34B in which the spare tire 38 is accommodated is lifted upward. As a result, the spare tire 38 can be rotated away from the fuel tank 36 and the rear seat (not shown) by rotating it in the direction of the arrow U so as to lift its front part upward. Further, by moving the spare tire 38 in this way, it is possible to suppress the movement of the spare tire 38 toward the front of the vehicle.

  The buckling position 10K is desirably set to a position where the spare tire 38 can be moved in this manner, and this can be appropriately controlled by adjusting the longitudinal length of the reinforcing member 12. Further, since the rear floor side member 10 is not provided with a weak portion such as a bead, the rear floor side member 10 can be buckled under a high load, and the impact energy absorption is high. Note that, when the vehicle is subjected to a rear collision at a relatively low speed, the influence of the collision does not reach the front portion of the rear floor side member 10, and repair costs can be suppressed.

  Next, the operation when towing or securing using the hook 28 will be described. In FIG. 8, when a load F caused by towing or lashing acts on the hook 28 obliquely downward, for example, the rear floor side member 10 receives a tensile load rearward of the vehicle, and the rear floor side member 10 and the intermediate plate are caused by the downward load component. A downward bending moment acts on the fastening portions of 14 and the rear bumper arm 16.

  However, in the vehicle rear structure S, since the lower load transmission portion 14E of the intermediate plate 14 is reinforced by the flange 14A, the vehicle has a high bending rigidity in the front-rear direction, which suppresses bending deformation due to the bending moment and reduces distortion. It is possible to reduce. Further, since the rear floor side member 10 is not provided with a weak portion such as a bead, the deformation of the rear floor side member 10 due to the traction load F can be suppressed.

  In the above embodiment, the reinforcing member 12 is described as an example of the reinforcing portion. However, the present invention is not limited to this, and the bottom portion 10J of the rear floor side member 10 may be partially reinforced. Therefore, for example, the bottom 10J of the rear floor side member 10 may be partially thick.

It is an expansion perspective view showing the important section of the vehicle rear part structure seen from the vehicle left rear. It is an expansion disassembled perspective view which shows the principal part of a vehicle rear part structure. FIG. 5 is an enlarged exploded perspective view showing an example in which a reinforcing flange is added to the lower edge of the lower load transmission portion of the intermediate plate in the vehicle rear structure. FIG. 5 is an enlarged exploded perspective view showing an example in which a reinforcing bead is formed in a lower load transmission portion of an intermediate plate in a vehicle rear structure. It is sectional drawing of the vehicle rear part structure at the time of normal use. FIG. 6 is a cross-sectional view showing a state in which a vehicle has been subjected to a rear collision and a rear floor side member has started to buckle at a buckling position. FIG. 7 is a cross-sectional view showing a state where the buckling further proceeds and the front part of the spare tire is rotated so as to be lifted upward and separated from the fuel tank following the state of FIG. 6. It is an expanded partial sectional view which shows the state in which the traction load is acting with respect to a hook.

Explanation of symbols

10 Rear floor side member 10E First lower flange 10J Bottom 12 Reinforcing member (reinforcing part)
14 Intermediate plate 14E Lower load transmission portion 16 Rear bumper arm 16E Second lower flange 26 Rear bumper reinforcement S Vehicle rear structure

Claims (2)

Rear floor side members extending in the vehicle front-rear direction on the left and right of the rear part of the vehicle,
A reinforcing portion that is provided in a range from a rear end to a predetermined position on the vehicle front side at the bottom of the rear floor side member, and suppresses buckling of the bottom in the range when the vehicle is subjected to a rear collision;
A vehicle rear structure characterized by comprising: A first lower flange extending downward from a rear end of the bottom of the rear floor side member;
An intermediate plate that is fixed to the rear side of the rear floor side member, overlaps the rear side of the first lower flange, and has a lower load transmission portion reinforced at least with respect to bending rigidity in the vehicle longitudinal direction;
A rear bumper arm fixed to the rear side of the intermediate plate and fixed to the front side of the rear bumper reinforcement, and having a second lower flange overlapping the rear side of the lower load transmitting portion of the intermediate plate;
The vehicle rear portion structure according to claim 1, comprising:

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