JP2007008346A - Vehicle rear part structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide vehicle rear part structure capable of effectively absorbing the collision load irrespective of the vehicle height of another vehicle colliding against the vehicle rear part. <P>SOLUTION: In the vehicle rear part structure 1, the collision load receiving from a bumper or the like of a collision vehicle is received by a lower back panel R/F3, when other vehicle (collision vehicle) collides with a vehicle rear part. Since the lower back panel R/F3 is vertically extended longer than the vertical width of a rear side member, the collision load can be received irrespective of the vehicle height of the collision vehicle. Additionally, since the lower back panel R/F3 is weld-fixed to the rear end part 2a of a rear side member 2, the collision load received by the lower back panel R/F3 is surely transmitted to the rear side member 2, and the absorption effect of the collision load is sufficiently exhibited by the buckling in the longitudinal direction of the rear side member 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle rear structure for absorbing an impact at the time of a collision.

  The body of various vehicles such as passenger cars has a structure for absorbing an impact when it collides with another vehicle or the like. In such a structure, generally, a bumper is attached to an end portion of a side member that is a skeleton member of a vehicle, and a load (collision load) generated by a collision is transmitted from the bumper to the side member. However, there are various types of vehicles with different vehicle heights, such as large trucks, light vehicles, and sports cars. Therefore, the bumper height often varies depending on each vehicle type, and vehicles with different bumper heights may collide with each other. In this case, the collision load is not efficiently transmitted from the bumper to the side member, and the impact at the time of the collision may not be sufficiently absorbed.

Therefore, for example, there is a vehicle front structure described in Patent Document 1 as a structure that considers a collision between vehicles having different vehicle heights. In this conventional vehicle front structure, a cross member disposed in the vehicle width direction at the front end of the side member, a side frame fixed to the lower portion of the side member, and supported by the front end of the side frame, And a subframe arranged in parallel downward. When bumper portions of vehicles having different vehicle heights collide with the sub frame, the side frame supporting the sub frame bends upward and interferes with the side member, and the impact load is transmitted to the side member.
JP 2003-146242 A

  However, the structure considering the collision between vehicles having different vehicle heights as described above is applied to the front portion of the vehicle, and has not been applied to the rear portion of the vehicle. Therefore, when vehicles having different vehicle heights collide with the rear part of the vehicle, there still remains a problem that the impact at the time of collision cannot be sufficiently absorbed.

  Further, in the structure described in Patent Document 1, a fixed portion between the side member and the side frame may be detached or the side member itself may be deformed upward due to the impact of a collision. In such a case, the collision load when another vehicle collides with the rear part of the vehicle is not sufficiently transmitted from the subframe to the side member (rear side member), and the collision load due to buckling of the side member is not sufficiently absorbed. There is a fear.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle rear structure that can effectively absorb the collision load regardless of the height of the collision vehicle that collides with the rear of the vehicle. And

  In order to solve the above-described problem, a vehicle rear structure according to the present invention includes a rear side member that is a part of a vehicle skeleton and extends in the front-rear direction of the vehicle, and a rear end portion of the rear side member extends in a vertical direction of the rear side member. A vertical member that is longer than the width and extends in the vertical direction of the vehicle is coupled.

  In this vehicle rear structure, when another vehicle (collision vehicle) collides with the vehicle rear portion, a collision load received from a bumper or the like of the collision vehicle can be received by the vertical member. At this time, since the vertical member extends vertically longer than the vertical width of the rear side member, it can receive a collision load regardless of the vehicle height of the collision vehicle. Further, in this vehicle rear structure, since the vertical member is coupled to the rear end portion of the rear side member, the collision load received by the vertical member is reliably transmitted to the rear side member, and the rear side member is buckled in the front-rear direction. The effect of absorbing the collision load due to is sufficiently exhibited.

  Moreover, it is preferable that an up-down direction member is a closed cross-section structure.

  If bending deformation occurs in the vertical member when the bumper beam of the collision vehicle hits the vertical member, the transmission efficiency of the collision load from the vertical member to the rear side member may decrease. On the other hand, when the vertical member has a closed cross-sectional structure, the bending strength of the vertical member can be increased. Thereby, the bending deformation of the vertical member at the time of the collision is suppressed, and the collision load can be transmitted to the rear side member more efficiently.

  Further, the width in the vehicle width direction of the vertical member is preferably the same as the width of the rear side member in the vehicle width direction.

  In this case, since the side surface of the vertical member and the side surface of the rear side member can be flush with each other, bending deformation in the vicinity of the coupling portion of the vertical member with the rear side member can be more reliably suppressed. Thereby, a collision load can be more efficiently transmitted from a vertical member to a rear side member. Note that the same width here does not have to be exactly the same width, and includes some differences.

  The bending strength of the vertical member is preferably larger than the compressive strength of the rear side member in the longitudinal direction of the vehicle.

  If it carries out like this, it can suppress that the bending deformation of an up-down direction member arises before buckling of a rear side member. Therefore, the collision load can be more reliably transmitted from the vertical member to the rear side member.

  The vehicle further includes a longitudinal support member that is coupled to the vehicle skeleton and extends in the longitudinal direction of the vehicle. The vertical member is provided at a rear end of the longitudinal support member at least one of the upper side of the rear side member and the lower side of the rear side member. It is preferably supported.

  In this case, the vertical member is supported at two or more locations on at least one of the upper and lower sides of the rear side member by the front and rear direction support member. Therefore, the bending strength of the vertical member can be further improved.

  In addition, it is preferable that a front-rear impact absorbing member extending in the front-rear direction of the vehicle is coupled to the rear side of the upper-lower direction member, which has a lower compressive strength in the front-rear direction of the vehicle than the rear side member.

  Since the height position of the front-rear direction impact absorbing member can be arbitrarily set on the rear side of the up-down direction member, the degree of freedom in designing the height position of the bumper beam connected to the front-rear direction impact absorbing member can also be increased. Thereby, it becomes possible to unify the position of the bumper beam between the vehicle types having different vehicle heights.

  The longitudinal shock absorbing member may be located between a height position where the rear side member is coupled to the vertical member and a height position where the longitudinal support member is coupled to the vertical member. preferable.

  With such a configuration, since the front-rear direction impact absorbing member is reliably supported by the up-down direction member, the impact absorbing effect by the front-rear direction impact absorbing member can be enhanced. In addition, since the degree of freedom in designing the height position of the bumper beam connected to the front-rear direction impact absorbing member can be increased, it is possible to unify the position of the bumper beam between vehicle types having different vehicle heights.

  Moreover, it is preferable that the rear-end part of the front-back direction supporting member is couple | bonded with the front side of the said up-down direction member.

  Thereby, the bending strength of the vertical member can be further improved, and the collision load can be more reliably transmitted from the vertical member to the rear side member.

  As described above, according to the vehicle rear structure according to the present invention, the collision load can be effectively absorbed regardless of the vehicle height of the collision vehicle that collides with the vehicle rear.

  Hereinafter, preferred embodiments of a vehicle rear structure according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a perspective view showing a vehicle rear structure according to a first embodiment of the present invention, and FIG. 2 is a side view thereof. As shown in FIGS. 1 and 2, the vehicle rear structure 1 is a structure that is applied to the rear part of various types of vehicles such as SUVs and sports cars, and when another vehicle (collision vehicle) collides with the rear part of the vehicle. It is a structure for absorbing the generated impact.

  The vehicle rear structure 1 includes a rear side member 2, a lower back panel reinforcement (vertical member, hereinafter referred to as “lower back panel R / F”) 3, a rear suspension cross member (front / rear direction support member) 4, A crash box (front-rear direction impact absorbing member) 5 and a rear bumper beam 6 are provided.

  The rear side members 2 are skeletal members that extend in the front-rear direction of the vehicle, and are arranged in a pair on the left and right sides with an engine unit (not shown) of the vehicle interposed therebetween in order to increase the strength of the vehicle. When the collision vehicle collides with the rear part of the vehicle, the rear side member 2 receives a collision load generated by the collision from the lower back panel R / F3. When the transmitted collision load exceeds the compressive strength of the rear side member 2, the rear side member 2 absorbs the collision load by buckling in the front-rear direction of the vehicle and reduces the impact.

  The lower back panel R / F 3 is a skeleton member of a back panel (not shown) of the vehicle and a load transmission member that transmits a collision load received from the collision vehicle to the rear side member 2. The lower back panel R / F3 extends in the vertical direction of the vehicle longer than the vertical width of the rear side member 2, and the substantially central portion on the front side of the lower back panel R / F3 has left and right rear side members. 2 are fixed to the rear end portion 2a by welding. The width of the lower back panel R / F3 in the vehicle width direction is the same as the width of the rear side member 2 in the vehicle width direction, and the left and right side surfaces of the rear side member 2 and the left and right sides of the lower back panel R / F3. Each side is flush with each other.

  Here, FIG. 3 shows a cross-sectional structure of the lower back panel R / F3. 3 is a cross-sectional view taken along line III-III in FIG. As shown in FIG. 3A, the lower back panel R / F3 has a closed cross-sectional structure made of a hollow mold member 30 having a rectangular cross section. With such a closed cross-sectional structure, the bending strength of the lower back panel R / F3 is larger than the compressive strength of the rear side member 2 in the front-rear direction.

  Note that, as in the lower back panel R / F3A shown in FIG. 3B, a closed section structure is formed by bending the mold 30A into a rectangular cross section so that one piece is overlaid, and arc welding the overlapped portion. May be. Further, as in the lower back panel R / F 3B shown in FIG. 3C, two molds 30B and 30B having a U-shaped cross section face each other to form a hollow portion, and the side walls 31 and 31 of the molds 30B and 30B are formed. A closed cross-sectional structure may be formed by overlapping the tips of the two and arc welding.

  The rear suspension cross member 4 is a member for assembling a rear suspension (not shown). As shown in FIGS. 1 and 2, the rear suspension cross member 4 includes a flat plate-like main body portion 40 to which the rear suspension is assembled, and a pair of left and right columnar connection portions 41. And the main-body part 40 is extended in the width direction of the vehicle, and is being firmly fixed to the lower part of the intermediate part of the right-and-left rear side member 2 with the volt | bolt.

  Further, the connecting portion 41 protrudes from the rear side of the left and right side portions of the main body portion 40 toward the rear side of the vehicle, and the rear end portion 41a of the connecting portion 41 is located on the lower side of the left and right lower backs below the rear side member 2. It is welded and fixed to the front side of the panel R / F3. As a result, the lower back panel R / F 3 is supported at two points by the rear end portion 2a of the rear side member 2 and the connecting portion 41 of the rear suspension cross member 4, and the bending strength against the collision load is further secured. The rear end portion 41a of the connecting portion 41 and the front side of the lower back panel R / F3 may be fixed via a rubber bush (not shown) in order to reduce vibration in the vehicle interior. Here, when the rear end portion 41a of the connecting portion 41 and the front side of the lower back panel R / F3 are fixed via a rubber bush, the main body portion 40 is arranged below the rear side member 2 in the vertical direction. You may couple | bond so that it may rotate.

  The crash box 5 is a member that supports the rear bumper beam 6 and that absorbs a collision load received from a collision vehicle. The crash box 5 is welded and fixed to the rear side of the left and right lower back panels R / F 3 at a substantially intermediate height position between the rear side member 2 and the rear suspension cross member 4 and extends in the front-rear direction of the vehicle. ing. Further, the compressive strength in the front-rear direction of the crash box 5 is set to be smaller than the compressive strength in the front-rear direction of the rear side member 2. Therefore, the crash box 5 quickly starts the compression in the front-rear direction against a minor collision such as a collision at a low speed, and absorbs the collision load without deforming the rear side member 2.

  Further, the mounting position of the crash box 5 can be offset vertically on the rear side of the lower back panel R / F3. This increases the degree of freedom in designing the height position of the rear bumper beam 6 connected to the crash box 5 and makes it possible to unify the height position of the rear bumper beam between vehicle types having different vehicle heights.

  However, the crash box 5 is located between the height position where the rear side member 2 is fixed to the lower back panel R / F3 and the height position where the rear suspension cross member 4 is fixed to the lower back panel R / F3. It is preferable to attach to the height position. In this range, since the crash box 5 is reliably supported by the lower back panel R / F 3, the impact load absorbing effect by the crash box 5 can be sufficiently secured.

  The rear bumper beam 6 is a member that supports a rear bumper (not shown). The rear bumper beam 6 is fixed to the rear end portions 5a of the left and right crash boxes 5 and extends in the width direction of the vehicle. The rear bumper beam 6 transmits the collision load received from the collision vehicle to the lower back panel R / F 3 side and the rear side member 2 side.

  Next, the impact absorption effect of the vehicle rear structure 1 having the above-described configuration will be described.

  First, the impact absorbing action of the vehicle rear structure 1 when the height position of the rear bumper beam 6 of the vehicle to which the vehicle rear structure 1 is applied is substantially the same as the height position of the front bumper of the collision vehicle will be described. In this case, as shown in FIG. 4A, when the collision vehicle collides with the rear part of the vehicle, the collision load from the front bumper B of the collision vehicle is first applied to the rear bumper beam 6, and then from the rear bumper beam 6 to the crash box 5. Communicated. At this time, the crash box 5 absorbs a certain amount of the collision load transmitted by compressing and deforming in the front-rear direction. The collision load that cannot be absorbed by the crash box 5 is transmitted to the lower back panel R / F3.

  Here, the lower back panel R / F 3 that has received the transmission of the collision load has a closed space structure (see FIG. 3), and a connecting portion between the rear end 2 a of the rear side member 2 and the rear suspension cross member 4. Since it is supported at two points by 41, it has a sufficiently large bending strength against the collision load. Therefore, it is possible to suppress the lower back panel R / F3 from being extremely bent by the collision load, and the collision load is efficiently transmitted from the lower back panel R / F3 to the rear side member 2.

  Further, since the side surfaces of the lower back panel R / F3 and the rear side member 2 are flush with each other, bending deformation in the vicinity of the joint portion between the lower back panel R / F3 and the rear side member 2 is more reliably suppressed. . Thereby, the further improvement of the transmission efficiency of the collision load from the lower back panel R / F3 to the rear side member 2 is achieved. Thereafter, the rear side member 2 to which the collision load is transmitted absorbs the collision load while buckling in the front-rear direction, and effectively reduces the impact caused by the collision.

  On the other hand, depending on the type of the collision vehicle, the height position of the rear bumper of the vehicle may be different from the height position of the front bumper of the collision vehicle. In such a case, it is conceivable that the front bumper of the collision vehicle does not hit the rear bumper at the rear of the vehicle in the event of a collision, and the transmission efficiency of the collision load to the rear side member is reduced.

  On the other hand, the vehicle rear portion structure 1 includes a lower back panel R / F3 that extends in the vertical direction of the vehicle longer than the vertical width of the rear side member 2, as shown in FIG. 4B. Therefore, even when the front bumper B of the collision vehicle does not hit the rear bumper beam 6 of the vehicle rear structure 1, it is possible to directly receive the collision load from the front bumper B of the collision vehicle by the lower back panel R / F3. The collision load applied to the lower back panel R / F 3 is efficiently transmitted to the rear side member 2 as in the case of FIG. 4A, and is effectively absorbed by the buckling of the rear side member 2 in the front-rear direction. The As described above, the vehicle rear structure 1 can effectively absorb the impact at the time of the collision even when the vehicle having different bumper height due to the vehicle height collides with the vehicle rear.

[Second Embodiment]
Then, the vehicle rear part structure which concerns on 2nd Embodiment of this invention is demonstrated.

  As illustrated in FIG. 5, the vehicle rear structure 10 according to the second embodiment includes a lower back panel R / F 3 that is a vertical member, a rear side member 2, a rear suspension cross member 4, and a belt line portion reinforcement ( The lower back panel R / F 3 is supported at two points by the rear side member 2 and the rear suspension cross member 4 in that it is supported at three points by a longitudinal support member (hereinafter referred to as “belt line portion R / F”) 7. This is different from the first embodiment supported by the above.

  That is, the vehicle rear portion structure 10 further includes a belt line portion R / F 7 extending in the front-rear direction of the vehicle, and the rear end portion 7a of the belt line portion R / F 7 is located above the rear side member 2 and the lower back panel R. The front end portion 7b of the belt line portion R / F7 is welded and fixed to a wheel house 8 which is a part of the vehicle skeleton. The belt line portion R / F 7 may be coupled to a skeleton member other than the wheel house 8 as long as it is a part of the vehicle skeleton.

  In the vehicle rear structure 10 configured as described above, the bending strength of the lower back panel R / F 3 can be further improved by supporting at three points. Therefore, the bending of the lower back panel R / F3 due to the collision load can be more reliably suppressed, and the collision load can be efficiently transmitted from the lower back panel R / F3 to the rear side member 2.

  Also, the offset position of the crash box 5 is the height position where the belt line portion R / F7 is fixed to the lower back panel R / F3 and the lower back panel R / F3 on the rear side of the lower back panel R / F3. The rear suspension cross member 4 can be expanded to a height position where the rear suspension cross member 4 is fixed. This further increases the degree of freedom in designing the height position of the rear bumper beam 6 connected to the crash box 5, and makes it possible to more easily realize the unification of the height position of the rear bumper beam among different vehicle types.

  The present invention is not limited to the above embodiment, and various modifications can be applied. For example, in each of the above embodiments, the lower back panel R / F 3 is supported at two points or supported at three points, but from the viewpoint of effectively absorbing the collision load regardless of the height of the collision vehicle. The lower back panel R / F 3 may be simply configured to be supported only by the rear side member 2. In order to further simplify the configuration, the crash box 5 and the rear bumper beam 6 are not necessarily provided.

  In each of the above embodiments, the crash box 5 is welded and fixed to the rear side of the lower back panel R / F3. However, a plurality of positioning bolt holes are provided in the vertical direction on the rear side of the lower back panel R / F3. In addition, the crash box 5 may be attached to one of the bolt holes by a bolt. In this case, even after attachment, the height position of the crash box 5 and the rear bumper beam 6 connected to the crash box 5 can be adjusted.

1 is a perspective view showing a vehicle rear structure according to a first embodiment of the present invention. It is a side view of the vehicle rear part structure shown in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2, (a) is a sectional structure of a lower back panel R / F, (b) is a sectional structure of a lower back panel R / F according to a modification, and (c) is further separated. The cross-section of the lower back panel R / F which concerns on the modification of this is shown. (A) is a figure which shows the impact absorption effect | action in a vehicle rear part structure in case the height position of the rear bumper of a vehicle and the height position of the front bumper of a collision vehicle are the same, (b) is the height of the rear bumper of a vehicle. It is a figure which shows the impact-absorbing effect | action in a vehicle rear part structure in case a height position and the height position of the front bumper of a collision vehicle differ. It is a perspective view which shows the vehicle rear part structure which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,10 ... Vehicle rear part structure, 2 ... Rear side member, 2a ... Rear end part, 3 ... Lower back panel R / F, 4 ... Rear suspension cross member, 5 ... Crash box, 7 ... Belt line part R / F, 8 … Wheel house.

Claims (8)

A rear side member that is a part of the vehicle skeleton and extends in the front-rear direction of the vehicle,
A vehicle rear portion structure, wherein a vertical member extending in a vertical direction of the vehicle longer than a vertical width of the rear side member is coupled to a rear end portion of the rear side member.   2. The vehicle rear structure according to claim 1, wherein the vertical member has a closed cross-sectional structure.   The vehicle rear portion structure according to claim 1, wherein a width of the vertical member in the vehicle width direction is the same as a width of the rear side member in the vehicle width direction.   The vehicle rear portion structure according to any one of claims 1 to 3, wherein a bending strength of the vertical member is greater than a compressive strength of the rear side member in a longitudinal direction of the vehicle. A front-rear direction support member coupled to the vehicle skeleton and extending in the front-rear direction of the vehicle;
The vertical member is
The vehicle rear portion structure according to any one of claims 1 to 4, wherein the vehicle rear portion structure is supported by a rear end portion of the front-rear direction support member at least one of the upper side of the rear side member and the lower side of the rear side member. .   The front-rear direction impact absorbing member extending in the front-rear direction of the vehicle is coupled to the rear side of the up-down direction member, and has a compressive strength in the front-rear direction of the vehicle smaller than that of the rear side member. The vehicle rear structure according to claim 5.   The front-rear impact absorbing member is located between a height position where the rear side member is coupled to the vertical member and a height position where the front-rear support member is coupled to the vertical member. The vehicle rear portion structure according to claim 6.   The vehicle rear portion structure according to any one of claims 5 to 7, wherein a rear end portion of the front-rear direction support member is coupled to a front side of the vertical direction member.

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