JP5742603B2 - Vehicle rear structure - Google Patents

Description

  The present invention relates to a vehicle rear structure.

  The side member outer panel has a structure in which the lower end of the lower back panel is coupled to the outer end in the vehicle width direction and a raised portion is formed in the vicinity of the front side of the coupling portion in the vehicle width direction. (For example, refer to Patent Document 1).

JP 2009-166634 A

  However, in such a structure, when a load is input from the rear side member side to the rear lower end portion of the side member outer panel through the lower back panel due to road surface input when traveling on a rough road, the side member outer panel is raised. Stress may concentrate on the ridge line portion along the vehicle width direction inner side end of the rear part. There is room for improvement in mitigating such stress.

  In view of the above fact, an object of the present invention is to obtain a vehicle rear portion structure that can alleviate stress concentration acting on the rear lower end portion of the side member outer panel.

  The vehicle rear portion structure of the present invention described in claim 1 is arranged at the rear lower portion of the vehicle body, and constitutes a lower back panel extending in the vehicle width direction, a vehicle body side portion, and a rear end flange formed at the rear lower end portion. The side member outer panel is connected to the outer end of the lower back panel in the vehicle width direction, and is formed at the rear lower end of the side member outer panel. Formed on the rear lower end portion of the side member outer panel, bent from the substrate portion, and erected outward in the vehicle width direction, and substantially toward the rear side of the vehicle Formed on the rear lower end portion of the side member outer panel, and a rear width portion of the side member outer panel. Outer edge A top portion having a top surface that is bent from approximately the vehicle width direction and a low-rigidity structure that is provided on the top portion and weakens a part of the top portion compared to other portions of the top portion; Have

  According to the vehicle rear portion structure of the present invention as set forth in claim 1, the lower back panel is disposed at the rear lower portion of the vehicle body and extends in the vehicle width direction, whereas the side member outer panel constitutes the vehicle body side portion. A rear end flange portion is coupled to an end portion on the outer side in the vehicle width direction of the lower back panel. For this reason, for example, when the vehicle body is deformed into a parallelogram shape when viewed from the front of the vehicle when traveling on rough roads, a load directed toward one side in the vehicle width direction with a relatively large road surface input load is applied to the lower back panel. In contrast, since the side member outer panel tends to remain in the initial position, the end portion of the lower back panel is elastically deformed into a substantially V shape in the vehicle plan view on the vehicle rear side on one side in the vehicle width direction. To do.

  On the other hand, at the rear lower end portion of the side member outer panel, there is provided a base plate portion that is provided continuously with the rear end flange portion and directed to the outside in the vehicle width direction, and is bent from the base plate portion in the vehicle width direction outer side. And a standing part having a rear surface substantially directed to the rear side of the vehicle. For this reason, with the elastic deformation of the lower back panel, a load including a component toward the vehicle front side acts on the boundary portion between the base plate portion and the rear surface of the standing portion.

  Here, at the rear lower end portion of the side member outer panel, a lower surface which is continuous with the rear surface of the standing portion and directed toward the vehicle lower side constitutes a part of the standing portion, and the vehicle width direction of the standing portion A top portion having a top surface that is bent from the outer end portion and is directed substantially outward in the vehicle width direction is formed. For this reason, when a load including a component toward the front side of the vehicle is applied to the boundary between the base plate portion and the rear surface of the standing portion, if the top portion extends substantially in the vehicle front-rear direction and generates a reaction force, the base plate portion And a load for reducing the angle formed by the rear surface of the standing portion.

  However, in the present invention, the top portion is provided with a low-rigidity structure that weakens a part of the top portion compared to other portions of the top portion, so that a load including a component toward the vehicle front side with respect to the top portion is provided. When input, the amount of elastic deformation at the top increases as compared with a comparative structure in which a low-rigidity structure is not provided. For this reason, when a load including a component toward the front side of the vehicle is applied to the boundary between the base plate portion and the rear surface of the standing portion, reaction force due to the top portion is suppressed, so the base portion and the rear surface of the standing portion are formed. The load to reduce the angle can be suppressed. That is, when the bent portion formed by the substrate portion and the rear surface side of the standing portion is about to be deformed, the portion forming the low rigidity structure is deformed so as to absorb the deformation, so that the substrate portion and the standing portion are The stress acting on the boundary portion of the rear surface is relaxed.

  According to a second aspect of the present invention, there is provided the vehicle rear portion structure according to the first aspect, wherein the rear lower end portion of the standing portion is an arcuate corner portion in a side view of the vehicle, and the low rigidity structure. Are the arc line of the corner part, the first imaginary straight line drawn from the upper end of the arc of the corner part to the vehicle front side, and the second imaginary line drawn from the arc front end of the corner part to the vehicle upper side in a side view of the vehicle. It is formed at a position including a range surrounded by straight lines.

  According to the vehicle rear portion structure of the present invention described in claim 2, the rear lower end portion of the standing portion is an arcuate corner portion when viewed from the side of the vehicle. A load including a component toward the vehicle front side acts on a boundary portion between the rear surface side and the substrate portion. Here, in a side view of the vehicle, an arc line of the corner portion, a first imaginary straight line drawn from the upper end of the arc of the corner portion to the vehicle front side, and a second imaginary straight line drawn from the arc front end of the corner portion to the vehicle upper side The low-rigidity structure is formed at a position including the range surrounded by. For this reason, when a load including a component toward the vehicle front side acts on the boundary portion between the rear surface side of the corner portion and the substrate portion, the top portion is elastically deformed at a portion close to the boundary portion.

  According to a third aspect of the present invention, there is provided the vehicle rear portion structure according to the first or second aspect, wherein the low-rigidity structure includes a step structure that forms a step difference in the vehicle width direction. Yes.

  According to the vehicle rear portion structure of the present invention described in claim 3, the low rigidity structure includes a step structure that forms a step-like height difference in the vehicle width direction. Even if the load including the component repeatedly acts and the top portion is repeatedly elastically deformed, the elastic restoring force of the top portion is easily maintained.

The vehicle rear portion structure according to a fourth aspect of the present invention is the structure according to any one of the first to third aspects, wherein the top portion includes a portion forming the top surface and a portion forming the top surface. A lower step portion that does not overlap with the vehicle side view and is stepped inward in the vehicle width direction, and an inclined portion that connects the lower step portion and a portion forming the top surface, the lower step portion and the inclined portion And a second bent portion having a connecting portion between the inclined portion and the portion forming the top surface are formed in pairs at different positions in the vehicle front-rear direction. The low-rigidity structure includes the first bent portion and the substantially vehicle that are elastically deformed substantially inward in the vehicle width direction when a load from the vehicle rear side to the vehicle front side is input to the top portion. toward the widthwise outer Ru and a said second bent portion is elastically deformed.

According to the vehicle rear portion structure of the present invention described in claim 4, the top portion includes the first bent portion and the second bent portion constituting the low-rigidity structure formed in pairs at different positions in the vehicle front-rear direction. cage, when a load from the vehicle rear side to the front side of the vehicle relative to the top is inputted, the second bent portion is substantially the vehicle together with the first bent portion is elastically deformed substantially toward the vehicle width direction inside It is elastically deformed toward the outside in the width direction. For this reason, when a load from the vehicle rear side to the vehicle front side is input to the top, it is easy to ensure the amount of elastic contraction of the top in the vehicle front-rear direction.

  According to a fifth aspect of the present invention, in the vehicle rear portion structure of the present invention, in the configuration according to any one of the first to fourth aspects, the low-rigidity structure is formed at a portion from the top portion to the standing portion. Has been.

  According to the vehicle rear structure of the present invention described in claim 5, since the low-rigidity structure is formed in a portion from the top portion to the standing portion, the rigidity from the top portion to the standing portion is reduced, and the top portion is formed. On the other hand, when a load including a component toward the vehicle front side is input, the amount of elastic deformation at the top is easily secured.

  As described above, the vehicle rear portion structure according to the first aspect of the present invention has an excellent effect that stress concentration acting on the rear lower end portion of the side member outer panel can be reduced.

  According to the vehicle rear structure according to claim 2, when a load including a component toward the vehicle front side acts on a boundary portion between the rear surface of the corner portion and the base plate portion in the side member outer panel, the top portion is used as the boundary portion. Since it can be elastically deformed in a close part, it has the outstanding effect that the reaction force by the top part of a side member outer panel can be controlled effectively.

  According to the vehicle rear portion structure of the third aspect, there is an excellent effect that the durability strength of the rear lower end portion of the side member outer panel can be easily ensured.

According to the vehicle rear structure according to claim 4, when a load from the vehicle rear side to the vehicle front side is input to the top of the side member outer panel, the first bent portion and the second bent portion are By elastically deforming in directions opposite to each other, there is an excellent effect that the reaction force by the top can be effectively suppressed.

  According to the vehicle rear structure according to the fifth aspect, the rigidity from the top portion to the standing portion can be effectively reduced, and a load including a component toward the vehicle front side is input to the top portion of the side member outer panel. When it is done, it has the outstanding effect that the reaction force by a top part can be suppressed effectively.

1 is a perspective view showing a vehicle body to which a vehicle rear portion structure according to a first embodiment of the present invention is applied. It is a perspective view which expands and shows the lower right end part of the vehicle body rear part of FIG. It is a disassembled perspective view which decomposes | disassembles and shows FIG. It is a figure which expands and shows the principal part of the vehicle rear part structure which concerns on the 1st Embodiment of this invention. FIG. 4A is a side view seen from the outside in the vehicle width direction. FIG. 4B is a bottom view seen from the vehicle lower side. FIG. 5 is a cross-sectional view in plan view schematically showing the right side of the vehicle rear structure according to the first embodiment of the present invention (corresponding to a cross-sectional view taken along line 5-5 in FIG. 2). It is sectional drawing of planar view for demonstrating the effect | action of the vehicle rear part structure which concerns on the 1st Embodiment of this invention. 6A is an enlarged cross-sectional view taken along line 6A-6A in FIG. FIG. 6B shows a state where the side member outer panel and the like are elastically deformed from the state of FIG. It is sectional drawing of planar view which shows the principal part of the vehicle rear part structure which concerns on the 2nd Embodiment of this invention. It is sectional drawing of planar view which shows the principal part of the vehicle rear part structure which concerns on the 3rd Embodiment of this invention.

[First Embodiment]
A vehicle rear structure according to a first embodiment of the present invention will be described with reference to FIGS. In these drawings, an arrow RE appropriately shown indicates the vehicle rear side, an arrow UP indicates the vehicle upper side, and an arrow OUT indicates the vehicle width direction outer side.

  FIG. 1 is a perspective view of a vehicle body 10 to which a vehicle rear structure according to the first embodiment of the present invention is applied. As shown in FIG. 1, a rear door opening 12 that is opened and closed by a rear side door (not shown) is formed on the side of the vehicle body rear portion 10 </ b> A. A rocker rear 14 extends along the vehicle front-rear direction on the lower edge side of the rear door opening 12. Although detailed illustration is omitted, the rocker rear 14 basically forms a closed cross-sectional structure extending along the vehicle front-rear direction by joining the upper and lower flange portions of the inner panel and the outer panel. A rear wheel house 16 is disposed on the rear end side of the rocker rear 14. The rear wheel house 16 is a member that covers the upper side of a rear wheel tire (not shown), and the upper front end side of the rear wheel house 16 is connected to the rear end side of the rocker rear 14 while drawing a gentle curve.

  FIG. 2 is an enlarged perspective view of the right lower end portion of the vehicle body rear portion 10A of FIG. 1, and FIG. 3 is an exploded perspective view of FIG. 2 in an exploded state. As shown in FIG. 3, the rear wheel house 16 includes a wheel house inner 18 that is a component on the inner side in the vehicle width direction, and a wheel house outer 20 that is a component on the outer side in the vehicle width direction. .

  The wheel house inner 18 bulges toward the inner side in the vehicle width direction, and includes a rear end flange portion 18A having a joining surface directed in the vehicle width direction at a rear end side outside the vehicle width direction. In addition, a vertical wall portion 18B is formed on the rear end lower portion side with a general surface substantially directed toward the vehicle rear side. On the other hand, the wheel house outer 20 is slightly raised outward in the vehicle width direction, and a rear end provided with a joint surface directed in the vehicle width direction at a rear inner side in the vehicle width direction. A vertical wall portion 20B having a flange portion 20A and having a general surface substantially directed toward the rear of the vehicle is formed on the rear end lower side. The rear end flange portion 18A of the wheel house inner 18 and the rear end flange portion 20A of the wheel house outer 20 are joined to each other (see FIG. 6A).

  Note that an upper end side attachment portion (rear attachment portion to the vehicle body 10 side) of a shock absorber constituting a rear suspension (not shown) is attached to the wheel house inner 18 via another member (not shown). Further, a part of the side member outer panel 50 constituting the vehicle body side portion is overlaid on the outer side in the vehicle width direction of the wheel house outer 20. A curved lower end flange portion 20C is formed at the lower end of the wheel house outer 20, and a curved lower end flange portion 50A is formed at the lower end of the side member outer panel 50 so as to correspond thereto. These lower end flange portions 20C and 50A are joined to each other.

  The front end flange portion 22A of the wheel house extension 22 is joined to the front surface of the vertical wall portion 18B of the wheel house inner 18, and the front end flange portion 22B of the wheel house extension 22 is connected to the front surface of the vertical wall portion 20B of the wheel house outer 20. Are joined (see FIG. 6A). The wheel house extension 22 includes a general portion 22C extending in the vehicle vertical direction and having a general surface directed in the vehicle width direction. The front end flange portion 22A described above is a portion that is bent from the front end of the general portion 22C and extends inward in the vehicle width direction, and the front end flange portion 22B described above is cut and raised from the general portion 22C. It is the site | part extended from the front end to the vehicle width direction outer side.

  Further, a rear end flange portion 22D that is bent from the rear end of the general portion 22C and extends inward in the vehicle width direction is formed at the rear end of the wheel house extension 22. As shown in FIG. 6A corresponding to an enlarged cross-sectional view taken along line 6A-6A in FIG. 2, the rear end flange portion 22D of the wheel house extension 22 has a rear end flange portion 54 ( The front surface of the lower back panel 40 and the front surface of the end 40A on the outer side in the vehicle width direction are joined. Thus, the wheel house outer 20, the wheel house extension 22, and the side member outer panel 50 form a closed cross section C1.

  As shown in FIGS. 1 and 2, the lower back panel 40 is disposed on the lower edge side of the back door opening 42 (that is, the rear lower part of the vehicle body) and extends in the vehicle width direction, and the general surface is the front and rear of the vehicle. Is directed in the direction. A back side panel 44 is disposed on the side edge side of the back door opening 42, and a lower back gusset (an operation patch) is provided on the rear surface of the lower back panel 40 on the outer side 40 </ b> A side in the vehicle width direction. 46 is joined.

  As shown in FIG. 2, a rear floor pan 26 is disposed on the vehicle front side of the lower back panel 40. The rear floor pan 26 is formed by press molding or the like in a substantially reverse hat shape when viewed from the rear of the vehicle. That is, as shown in FIG. 3, the rear floor pan 26 includes a bottom portion 26A, a pair of left and right side portions 26B that are bent from both ends of the bottom portion 26A in the vehicle width direction and are erected substantially upward in the vehicle, and side portions. A pair of left and right terminal flange portions 26C that are bent from the upper end of 26B and extend outward in the vehicle width direction. The rear floor pan 26 is joined to the lower end portion of the lower back panel 40 by a rear end flange portion 26 </ b> D that is bent at the rear end portion and extends toward the vehicle upper side.

  The inner flange portion 28 </ b> A of the rear floor side panel 28 is joined to the upper surface of the end portion on the outer side in the vehicle width direction of the terminal flange portion 26 </ b> C of the rear floor pan 26. The rear floor side panel 28 is formed in a long plate shape and extends in the vehicle front-rear direction along the terminal flange portion 26C of the rear floor pan 26, and an inner flange portion 28A is formed at the inner end in the vehicle width direction. In addition, an outer flange portion 28C is formed at an end portion on the outer side in the vehicle width direction.

  A front end portion (not shown) of the outer flange portion 28C of the rear floor side panel 28 is joined to an upper end side of the above-described rocker rear 14 (see FIGS. 1 and 5) and an inner end portion in the vehicle width direction. The rear floor side panel 28 is joined to the lower back panel 40 by a rear end flange portion 28 </ b> D that is bent at the rear end portion and extends toward the vehicle upper side. As shown in FIG. 2, the arrangement position of the rear end flange portion 28 </ b> D is set slightly closer to the lower portion in the vehicle vertical direction intermediate portion of the lower back panel 40.

  A lower end portion of the rear floor extension 24 is disposed adjacent to the upper side of the end portion of the rear floor side panel 28 on the outer side in the vehicle width direction. The rear floor extension 24 is disposed adjacent to the inside of the wheel house extension 22 in the vehicle width direction (see FIG. 6A), and as shown in FIG. 3, the vertical wall portion whose general surface is oriented in the vehicle width direction. 24A and an upper wall portion 24B that is bent from the upper end of the vertical wall portion 24A and extends outward in the vehicle width direction. As shown in FIG. 6A, the rear floor extension 24 has a rear end flange portion 24C formed at the rear end thereof joined to the front surface of the lower back panel 40 near the end 40A in the vehicle width direction. In addition, the front end portion 24D is joined to the rear end side of the wheel house inner 18. Thus, a closed section C2 is formed by the wheel house inner 18, the wheel house extension 22, the rear floor extension 24, and the lower back panel 40.

  As shown in FIGS. 2 and 3, a rear side member 30 extends in the vehicle front-rear direction on the lower surface side of the rear floor side panel 28 (in other words, on both sides of the vehicle body rear portion 10A). In FIG. 6A, which corresponds to an enlarged sectional view taken along the line 6A-6A in FIG. 2, the rear side member 30 disposed on the lower side of the line 6A-6A in FIG. ) (The same applies to FIG. 6B). As shown in FIG. 3, the rear side member 30 is a strength member having an inverted cross-section with an open upper side of the vehicle body. That is, the rear side member 30 includes a bottom portion 30D, a pair of left and right side portions 30E and 30F that are bent from both ends in the vehicle width direction of the bottom portion 30D and are erected substantially upward in the vehicle, and a pair of side portions 30E and 30F. And a pair of left and right flange portions 30G and 30H that are bent from the upper end and extend in directions away from each other.

  The flange portion 30G on the inner side in the vehicle width direction of the rear side member 30 is joined to the outer end in the vehicle width direction of the terminal flange portion 26C of the rear floor pan 26 and the inner flange portion 28A of the rear floor side panel 28. Further, the outer side flange portion 30 </ b> H of the rear side member 30 is joined to the outer flange portion 28 </ b> C of the rear floor side panel 28. As a result, the rear side member 30 forms a closed section C3 (see FIG. 2) with the rear floor side panel 28.

  FIG. 5 is a schematic cross-sectional view (corresponding to a cross-sectional view taken along line 5-5 in FIG. 2) of the right side portion of the rear part 10A of the vehicle body. Note that the left side portion (not shown) of the vehicle body rear portion 10A has a structure in which the right side portion of the vehicle body rear portion 10A shown in FIG. Although not shown, a rear cross member having a longitudinal direction in the vehicle width direction is stretched between the left and right rear side members 30. Further, in FIG. 5, a part of the lower back panel 40 and the rear lower end portion 52 of the side member outer panel 50 arranged above the line 5-5 in FIG. 2 are illustrated by imaginary lines (two-dot chain lines). Yes.

  As shown in FIG. 5, in the pair of left and right rear side members 30 (only the right side is shown in FIG. 5), the rear portion 30 </ b> C is offset from the front portion 30 </ b> A inward in the vehicle width direction by bypassing the rear wheel 32. . The front portion 30 </ b> A of the rear side member 30 is disposed on the inner side in the vehicle width direction of the rear end portion of the rocker rear 14 and is coupled to the rear end portion of the rocker rear 14. On the other hand, the rear end portion 30I of the rear side member 30 is abutted against the front surface of the end portion 40A on the outer side in the vehicle width direction of the lower back panel 40, and is coupled to the lower back panel 40 via the transport hook 34. Has been.

  As shown in FIG. 3, the transport hook 34 includes a transport hook rear 36 that is a component on the inner side in the vehicle width direction, and a transport hook rear reinforcement 38 that is a component on the outer side in the vehicle width direction. I have.

  The upper portion 36B of the transport hook rear 36 is overlapped and joined to the side portion 30E of the rear side member 30 on the inner side in the vehicle width direction from the inner side in the vehicle width direction. Further, the upper end flange portion 36 </ b> A bent to the inner side in the vehicle width direction at the upper end portion of the transport hook rear 36 is joined to the flange portion 30 </ b> G on the inner side in the vehicle width direction of the rear side member 30.

  The transport hook rear 36 is bent from the lower end of the upper part 36B substantially outward in the vehicle width direction and is disposed on the vehicle lower side with respect to the rear side member 30, and the vehicle from the vehicle width direction outer end of the intermediate part 36C. And a lower part 36D suspended downward. A hook hole 36F is formed in the lower part 36D of the transport hook rear 36. A rear end flange portion 36E that is bent and extends inward in the vehicle width direction is formed at the rear end portion of the transport hook rear 36. The rear end flange portion 36E is joined to the front surface of the lower back panel 40 (see FIG. 5).

  The transport hook rear reinforcement 38 is used to reinforce the transport hook rear 36, and is arranged with the vehicle vertical direction as a longitudinal direction when viewed from the rear of the vehicle. The upper portion 38A of the transport hook rear reinforcement 38 is overlapped and joined to the side portion 30F of the rear side member 30 on the outer side in the vehicle width direction from the outer side in the vehicle width direction. The lower part 38B of the transport hook rear reinforcement 38 is overlapped and joined to the lower part 36D of the transport hook rear 36 from the outside in the vehicle width direction. A hook hole 38D is formed in the lower portion 38B of the transport hook rear reinforcement 38 at a position corresponding to the hook hole 36F of the transport hook rear 36. Further, a rear end flange portion 38 </ b> C that is bent and extends outward in the vehicle width direction is formed at the rear end portion of the transport hook rear reinforcement 38. The rear end flange portion 38C is joined to the front surface of the lower back panel 40 (see FIG. 5).

  Thus, the lower back panel 40 is coupled to the rear end portion 30I of the rear side member 30 by the transport hook rear 36 and the transport hook rear reinforcement 38.

  Further, as shown in FIG. 5, in the rear side member 30, a load input point A from a rear suspension (not shown) is set at an intermediate portion 30B connecting the front portion 30A and the rear portion 30C. In other words, a front attachment portion of the rear suspension toward the vehicle body 10 is attached to the intermediate portion 30B of the rear side member 30, and when traveling on a rough road, the front attachment portion of the rear suspension is connected to the rear side member. A substantially vehicle vertical load is input to 30 load input points A.

  On the other hand, a rear end flange portion 54 formed on a rear lower end portion 52 of the side member outer panel 50 is coupled to an end portion 40A on the outer side in the vehicle width direction of the lower back panel 40 shown in FIG. A)). The rear end flange portion 54 is a part of the outer peripheral end of the side member outer panel 50, and the joint surface with the lower back panel 40 is directed substantially toward the rear side of the vehicle.

  As shown in FIG. 4A, the rear lower end portion 52 of the side member outer panel 50 is provided with a side surface 56A provided continuously to the rear end flange portion 54 and directed outward in the vehicle width direction. A portion 56 is formed. In other words, the rear end flange portion 54 described above is a portion that is bent from the rear end of the base plate portion 56 and extends inward in the vehicle width direction. The base plate portion 56 is narrower than the rear end flange portion 54 and extends in the vehicle vertical direction, and the lower end portion is slightly wider than the rear end flange portion 54 and extends in the vehicle front-rear direction.

  In addition, a rear lower end portion 52 of the side member outer panel 50 is formed with a standing portion 58 that is bent from the base plate portion 56 and is erected outward in the vehicle width direction. The standing portion 58 includes a rear surface 58A directed substantially toward the rear side of the vehicle and a lower surface 58B continuous to the rear surface 58A and directed substantially toward the vehicle lower side. Further, the rear lower end portion of the standing portion 58 is set at a height position corresponding to the middle portion of the lower back panel 40 in the vehicle vertical direction, and is formed into an arcuate corner portion 58C (bag shape portion) in a vehicle side view. In addition, a hole 70 for removing the electrodeposition coating liquid (ED) is formed on the lower surface 58B side (flat portion) on the vehicle front side with respect to the corner portion 58C. Further, the vicinity of the inner end in the vehicle width direction at the upper end of the arc of the corner portion 58 </ b> C is a ridge line M <b> 1 that is a connection portion between the standing portion 58 and the substrate portion 56, and a connection portion between the substrate portion 56 and the rear end flange portion 54. It is a part (shape changing part) where the ridgeline M2 gathers.

  Further, the rear lower end portion 52 of the side member outer panel 50 is formed with a top portion 60 having a top surface 60A that is bent from the end portion of the standing portion 58 on the outer side in the vehicle width direction and is directed substantially outward in the vehicle width direction. ing.

The top 60 has an arc line of the corner portion 58C, a first virtual straight line L1 drawn in the horizontal direction from the upper end of the arc of the corner portion 58C, and a front end of the arc of the corner portion 58C. A step structure 62 as a low-rigidity structure is formed at a position including a range surrounded by a second virtual straight line L2 drawn on the vehicle upper side (in the vertical direction). As shown in FIGS. 4A and 4B, the step structure 62 forms a stepped height difference in the vehicle width direction, and is formed at a portion from the top 60 to the standing portion 58. ing. As shown in FIG. 4B, at the rear lower end portion 52 of the side member outer panel 50, the rear-side drawing depth D1 is smaller than the front-side drawing depth D2. And by making the site | part from the site | part which comprises the top surface 60A of the top part 60 to the standing part 58 into the vehicle width direction inner side, it is vehicle width direction inner side with respect to the site | part which comprises the top surface 60A of the top part 60 A lower step portion 64 that is lowered by one step and an inclined portion 66 that connects the lower step portion 64 and a portion forming the top surface 60A of the top portion 60 are formed.

The step structure 62 includes a first bent portion 68 </ b> A as a first low-rigidity portion having a connection portion (ridge line) between the lower step portion 64 and the inclined portion 66, and a top surface 60 </ b> A of the inclined portion 66 and the top portion 60. And a second bent portion 68B as a second low-rigidity portion having a connection portion (ridge line) with a portion that forms a portion is formed in pairs at different positions in the vehicle front-rear direction. The first bent portion 68A is configured to elastically deform the top portion 60 substantially inward in the vehicle width direction when a load from the vehicle rear side to the vehicle front side is input to the top portion 60. On the other hand, the second bent portion 68B is configured to elastically deform the top portion 60 substantially outward in the vehicle width direction when a load from the vehicle rear side to the vehicle front side is input to the top portion 60. It has become. That is, the step structure 62 has a structure in which a part of the top 60 is weakened as compared with other parts of the top 60.

(Action / Effect)
Next, the operation and effect of the above embodiment will be described.

  A load in the vertical direction of the vehicle is input from a rear suspension (not shown) to a load input point A of the rear side member 30 shown in FIG. When the magnitude of the input load to the load input point A of the rear side member 30 is different between the left and right rear side members 30 when traveling on a rough road or the like, the vehicle body 10 (see FIG. 1) is deformed into a parallelogram in front view of the vehicle. Try to (so-called matchbox deformation). At this time, a load that is directed obliquely outward in the vehicle width direction with respect to the upper side of the vehicle acts on one side of the pair of left and right rear side members 30 that has a large input load. A load F1 is applied to cause the rear end 30I of the rear side member 30 to be displaced outward in the vehicle width direction starting from the curved portion X between the portion 30B and the rear portion 30C. As a result, the rear portion 30C of the rear side member 30 tends to move to a position indicated by an imaginary line (two-dot chain line) in FIG. Thus, the rear end 30I of the rear side member 30 tends to approach relatively.

  On the other hand, as shown in FIG. 6B, the lower back panel 40 that connects the rear end portion 30I of the rear side member 30 and the rear lower end portion 52 of the side member outer panel 50 has a connecting portion 40C at the rear side. In order to absorb the relative displacement difference between the member 30 and the side member outer panel 50, the member 30 is elastically deformed toward the vehicle rear side (out-of-plane deformation in a substantially V shape in a vehicle plan view). As shown in FIG. 6A, the rear lower end portion 52 of the side member outer panel 50 is provided with a side surface 56A that is provided continuously with the rear end flange portion 54 and directed outward in the vehicle width direction. 6, and a standing portion 58 having a rear surface 58A that is bent from the substrate portion 56 and is erected outward in the vehicle width direction and substantially directed to the rear side of the vehicle. As shown in (B), with the deformation of the lower back panel 40, the inner end in the vehicle width direction of the rear end flange portion 54 is pulled toward the vehicle rear side, while the rear surface 58A of the base plate portion 56 and the standing portion 58 is provided. A load F2 directed toward the front side of the vehicle obliquely on the outer side in the vehicle width direction acts on the boundary portion B.

  Here, as shown in FIG. 4A, the rear lower end portion 52 of the side member outer panel 50 is provided with a lower surface 58B that is continuous with the rear surface 58A of the standing portion 58 and is directed substantially downward in the vehicle. A top portion 60 is formed that constitutes a part of the portion 58 and includes a top surface 60A that is bent from the end of the standing portion 58 on the outer side in the vehicle width direction and is directed substantially outward in the vehicle width direction. Therefore, as shown in FIG. 6B, when a load F2 including a component toward the front side of the vehicle acts on a boundary portion B between the base plate portion 56 and the rear surface 58A of the standing portion 58, the top portion 60 is obtained. When the reaction force F3 is generated by stretching substantially in the vehicle front-rear direction, a load is generated to reduce the angle formed by the base plate portion 56 and the rear surface 58A of the standing portion 58.

  However, in the present embodiment, the top portion 60 is formed with a step structure 62 that weakens a part of the top portion 60 as compared with other portions of the top portion 60. When a load including a component is input, the amount of elastic deformation of the top portion 60 is increased as compared with a contrast structure in which the step structure 62 is not formed. For this reason, when a load including a component toward the front side of the vehicle acts on the boundary B between the base plate portion 56 and the rear surface 58A of the standing portion 58, the reaction force F3 due to the top portion 60 is suppressed. A load for reducing the angle formed by the rear surface 58A of the installation portion 58 is suppressed.

  That is, by providing the step structure 62 at the top 60, the local deformation mode is changed, and the reaction force F3 by the top 60 is suppressed by the deformation at the first bent portion 68A and the second bent portion 68B. The change of the angle formed by the substrate portion 56 and the rear surface 58A of the standing portion 58 is suppressed. When the bent portion formed by the substrate portion 56 and the rear surface 58A side of the standing portion 58 is to be deformed, the first bent portion 68A and the second bent portion 68B are deformed so as to absorb the deformation. As a result, the stress acting on the boundary portion B between the substrate portion 56 and the rear surface 58A of the standing portion 58 is relieved.

  Further, as shown in FIG. 4A, the rear lower end portion of the standing portion 58 is an arc-shaped corner portion 58C as viewed from the side of the vehicle. A load including a component toward the front side of the vehicle acts on a boundary portion B between the rear surface 58A side and the substrate portion 56. Here, in the present embodiment, in a side view of the vehicle, the arc line of the corner portion 58C, the first virtual straight line L1 drawn from the arc upper end of the corner portion 58C to the vehicle front side, and the vehicle upper side from the arc front end of the corner portion 58C. A step structure 62 is formed at a position including a range surrounded by the second virtual straight line L2 drawn to the side. For this reason, when a load including a component toward the vehicle front side acts on the boundary portion B between the rear surface 58A side of the corner portion 58C and the substrate portion 56, the top portion 60 is elastically deformed at a portion close to the boundary portion B. Therefore, the reaction force F3 (see FIG. 6B) due to the top portion 60 of the side member outer panel 50 is effectively suppressed.

  The step structure 62 is formed at a position including a range surrounded by the arc line of the corner portion 58C, the first imaginary straight line L1, and the second imaginary straight line L2, so that the electrodeposition coating liquid (ED ) Can be effectively weakened while the hole 70 is formed in the flat plate portion of the lower surface 58B of the standing portion 58.

  Further, in the vehicle rear portion structure according to the present embodiment, a low-rigidity structure is formed by the step structure 62 having a stepped height difference in the vehicle width direction and including the first bent portion 68A and the second bent portion 68B. It is composed. For this reason, even if the load including the component toward the vehicle front side repeatedly acts on the top 60 and the top 60 is repeatedly elastically deformed, the elastic restoring force of the top 60 is easily maintained. And the durable strength of the rear lower end part 52 of the side member outer panel 50 is ensured easily.

  Further, the first bent portion 68A and the second bent portion 68B are formed in pairs at different positions in the vehicle front-rear direction, and as shown in FIG. 6B, from the vehicle rear side with respect to the top portion 60. When a load to the front side of the vehicle (a load including a component to the front side of the vehicle) is input, the top portion 60 is deformed toward the inner side in the vehicle width direction (see the arrow P direction) by the first bent portion 68A. The top portion 60 is deformed toward the outside in the vehicle width direction (see the arrow Q direction) by the second bent portion 68B. For this reason, when a load from the vehicle rear side to the vehicle front side (load including a component to the vehicle front side) is input to the top portion 60, the top portion 60 is bent and deformed in a so-called Z shape. The amount of elastic contraction of the top portion 60 in the vehicle front-rear direction is easily secured, and the reaction force F3 by the top portion 60 is effectively suppressed.

  In addition, as shown in FIG. 4A, the step structure 62 is formed at a portion from the top portion 60 to the standing portion 58. For this reason, the rigidity from the top portion 60 to the standing portion 58 is reduced, and when a load including a component toward the vehicle front side is input to the top portion 60, the amount of elastic deformation of the top portion 60 is easily secured. The reaction force F3 (refer FIG. 6 (B)) by the top part 60 is also suppressed effectively also at a point.

  As described above, according to the vehicle rear portion structure according to this embodiment, stress concentration acting on the rear lower end portion 52 of the side member outer panel 50 can be reduced.

  Moreover, in this embodiment, since the stress concentration to a local area can be reduced only by changing the surface shape of the rear lower end portion 52 of the side member outer panel 50, an increase in weight and cost can be suppressed. Further, the moldability is improved by reducing the drawing depth at the rear lower end 52 of the side member outer panel 50.

  In addition, in this embodiment, since the location which deform | transforms locally in the rear lower end part 52 of the side member outer panel 50 is changed, since the whole deformation | transformation of a vehicle does not change (the rigidity reduction of the whole vehicle does not change), There is no adverse effect on handling stability. Rather, steering stability is improved by reducing out-of-plane deformation (deformation toward the vehicle rear side) at both ends of the lower back panel 40 on the vehicle width direction outer side.

[Second Embodiment]
Next, a vehicle rear structure according to the second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view (a cross-sectional view corresponding to FIG. 6A of the first embodiment) of the main part of the vehicle rear structure according to the second embodiment of the present invention. Yes.

  As shown in FIG. 7, the vehicle rear structure according to the second embodiment is a low-rigidity structure formed at a position different from the step structure 62 instead of the step structure 62 (see FIG. 4A). The feature is that a bead 72 is provided. Other configurations are the same as those in the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The bead 72 is formed at a portion from the vehicle front-rear direction intermediate portion of the top portion 60 to the lower surface 58B (not shown, see FIG. 4) side of the standing portion 58. In other words, the lower end portion of the bead 72 is set so as to straddle a ridge line that is a connecting portion between the top surface 60A of the top portion 60 and the lower surface 58B of the standing portion 58 (not shown, see FIG. 4). The bead 72 is recessed inward in the vehicle width direction, and has a structure in which a part of the top portion 60 is weakened as compared with other portions of the top portion 60.

  According to the above configuration, when the bent portion formed by the base plate portion 56 and the rear surface 58A side of the standing portion 58 is to be deformed when traveling on a rough road or the like, the bead 72 is deformed so as to absorb the deformation. Thus, the stress acting on the boundary portion B between the substrate portion 56 and the rear surface 58A of the standing portion 58 is relieved. For this reason, the concentration of stress acting on the rear lower end portion 52 of the side member outer panel 50 can also be alleviated by the configuration of the present embodiment when traveling on a rough road.

  In order to weaken the top portion 60 more effectively by the bead 72, it is preferable that the bead 72 is deeper inward in the vehicle width direction, and the bead 72 is wider in the vehicle longitudinal direction. Further, in the second embodiment, one weakening bead 72 is formed on the top 60, but in order to weaken the top 60 more effectively, a plurality of weakening beads are formed. May be. Further, as a modification of the second embodiment, a bead as a low-rigidity structure that protrudes outward in the vehicle width direction may be formed instead of the bead 72 recessed inward in the vehicle width direction. Further, the lower end portion of the bead 72 may be configured not to straddle a ridge line that is a connection portion between the top surface 60A of the top portion 60 and the lower surface 58B of the standing portion 58 (not shown, see FIG. 4).

[Third Embodiment]
Next, a vehicle rear structure according to a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view (a cross-sectional view corresponding to FIG. 6A of the first embodiment) of the main part of the vehicle rear structure according to the third embodiment of the present invention. Yes.

  As shown in FIG. 8, the vehicle rear structure according to the third embodiment is configured such that a hole 74 as a low-rigidity structure is provided instead of the step structure 62 (see FIG. 4A). Is a feature. Other configurations are the same as those in the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The hole 74 is formed through a portion from the vehicle front-rear direction intermediate portion of the top portion 60 to the lower surface 58B (not shown, see FIG. 4) side of the standing portion 58. In other words, the lower end portion of the hole portion 74 is set so as to straddle the ridge line that is a connection portion between the top surface 60A of the top portion 60 and the lower surface 58B of the standing portion 58 (not shown, see FIG. 4). Further, in order to avoid excessive stress concentration at the opening peripheral end of the hole 74 when a load including a component toward the vehicle front side is applied to the top 60, the opening peripheral end of the hole 74 is Burring is performed, and a flange 76 extending inward in the vehicle width direction is formed. The hole 74 has a structure in which a part of the top 60 is weakened as compared with other parts of the top 60.

  According to the above configuration, when the bent portion formed by the base plate portion 56 and the rear surface 58A side of the standing portion 58 is deformed when traveling on a rough road or the like, the opening of the hole 74 is absorbed so as to absorb the deformation. By deforming the peripheral end, the stress acting on the boundary portion B between the substrate portion 56 and the rear surface 58A of the standing portion 58 is relaxed. For this reason, the concentration of stress acting on the rear lower end portion 52 of the side member outer panel 50 can also be alleviated by the configuration of the present embodiment when traveling on a rough road.

  In addition, in order to weaken the top 60 more effectively by the hole 74, it is preferable that the length of the hole 74 in the vehicle front-rear direction is longer. In the third embodiment, one weakening hole 74 is formed in the top 60, but in order to weaken the top 60 more effectively, a plurality of weakening holes are provided. May be formed. Further, the lower end portion of the hole portion 74 may be configured not to straddle a ridge line that is a connection portion between the top surface 60A of the top portion 60 and the lower surface 58B of the standing portion 58 (not shown, see FIG. 4). .

[Supplementary explanation of the embodiment]
In the first embodiment, as shown in FIG. 4 (A), the step structure 62 is formed on the vehicle front side from the arc line of the corner portion 58C and the arc upper end of the corner portion 58C in the vehicle side view. It is formed at a position including a range surrounded by the drawn first virtual straight line L1 and the second virtual straight line L2 drawn from the arc front end of the corner portion 58C to the vehicle upper side, and such a configuration is more preferable. However, the low-rigidity structure may be formed at a position that does not include the range surrounded by the arc line of the corner portion 58C, the first virtual straight line L1, and the second virtual straight line L2 in the vehicle side view.

  Moreover, in the said 1st Embodiment, the level | step difference structure 62 is formed in the site | part from the top part 60 to the standing part 58, and such a structure is more preferable, but a low-rigidity structure is formed only in the top part. Also good.

  In the first embodiment, the step structure 62 as the low-rigidity structure has a shape (concave step portion) in which a portion from the top portion 60 to the standing portion 58 is recessed inward in the vehicle width direction. However, the low-rigidity structure may have a shape (convex stepped portion) that protrudes outward in the vehicle width direction with respect to the top.

  In addition, the said embodiment and the above-mentioned some modification can be implemented combining suitably.

40 Lower back panel 50 Side member outer panel 54 Rear end flange portion 56 Substrate portion 56A Side surface 58 Standing portion 58A Rear surface 58B Lower surface 58C Corner portion 60 Top portion 60A Top surface 62 Step structure (low rigidity structure)
64 Lower part
66 Inclined portion 68A First bent portion 68B Second bent portion 72 Bead (low rigidity structure)
74 Hole (low rigidity structure)
L1 first virtual straight line L2 second virtual straight line

Claims (5)

A lower back panel disposed in the lower rear portion of the vehicle body and extending in the vehicle width direction;
A side member outer panel that constitutes a vehicle body side, and a rear end flange portion formed at a rear lower end portion is coupled to an end portion on the vehicle width direction outer side of the lower back panel;
A board portion having a side surface formed at a rear lower end portion of the side member outer panel and continuously provided to the rear end flange portion and directed outward in the vehicle width direction;
Formed at the rear lower end of the side member outer panel, bent from the base plate and erected outward in the vehicle width direction, substantially rearward of the vehicle, and substantially rearward of the rear surface. A standing portion comprising a lower surface directed to the side;
A top portion formed at a rear lower end portion of the side member outer panel, and having a top surface that is bent from an end portion on the vehicle width direction outside of the standing portion and directed substantially outward in the vehicle width direction;
A low-rigidity structure that is provided at the top and weakens a part of the top compared to other parts of the top;
A vehicle rear structure having: The rear lower end portion of the standing portion is an arcuate corner portion in a vehicle side view,
In the vehicle side view, the low-rigidity structure includes an arc line of the corner portion, a first imaginary straight line drawn from the upper end of the arc of the corner portion to the front side of the vehicle, and an upward direction of the vehicle from the arc front end of the corner portion. The vehicle rear portion structure according to claim 1, wherein the vehicle rear portion structure is formed at a position including a range surrounded by the second virtual straight line.   The vehicle rear structure according to claim 1, wherein the low-rigidity structure includes a step structure that forms a step-like height difference in the vehicle width direction. The top portion includes a portion forming the top surface, a lower step portion that does not overlap with the portion forming the top surface in a vehicle side view and is stepped inward in the vehicle width direction, and forms the top surface with the lower step portion. A first bent portion having a connecting portion between the lower step portion and the inclined portion, and a connecting portion between the inclined portion and the portion forming the top surface. Two folds are formed in pairs at different positions in the vehicle longitudinal direction,
The low rigidity structure, the first bent portion and the substantial vehicle transverse direction outer elastically deformed substantially toward the vehicle transverse direction inner side when a load is input from the vehicle rear side with respect to said top toward the front of the vehicle Ru and a said second bent portion is elastically deformed toward the vehicle rear portion structure according to any one of claims 1 to 3.   The vehicle rear portion structure according to any one of claims 1 to 4, wherein the low-rigidity structure is formed at a portion from the top portion to the standing portion.