JP2005206108A - Lower body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve transmission efficiency when transmitting a load input to one front side member to the other front side member.
In a plan view, bent portions 12B of a pair of left and right front side members 12 are inclined from the front in the vehicle width direction to the rear in the vehicle width direction, respectively, and from the rear end portion 12C of the bent portion 12B, An extending portion 12 </ b> D is formed along the floor tunnel portion 16 toward the rear of the vehicle body. Further, rear end portions 12C of the bent portion 12B of the pair of left and right front side members 12 are connected by an engine rear support member 20 as a connecting member, and the plan view shape of the engine rear support member 20 is an X shape. Yes.
[Selection] Figure 1

Description

  The present invention relates to a vehicle body lower structure, and more particularly, to a vehicle body lower structure such as an automobile having a side member at the vehicle body lower part.

2. Description of the Related Art Conventionally, in a lower body structure of a vehicle or the like having a side member at the lower part of the vehicle body, a bent portion inclined from the front in the vehicle width direction to the rear in the vehicle width direction at the rear part of the left and right front side members, There is known a configuration in which an extending portion extending rearward from the rear end portion along the floor tunnel portion is provided, and the rear end portions of the left and right bent portions are connected to each other by a connecting member (for example, , See Patent Document 1).
JP 2001-219873 A

  However, in patent document 1, the linear connection member is extended along the vehicle width direction in the vehicle body planar view. As a result, the load input to the front side member from the front side of the vehicle body extends from the bent portion inclined from the front in the vehicle width direction to the rear in the vehicle width direction, and extends from the bent portion to the rear of the vehicle body along the floor tunnel portion. And the load transmitted to the connecting member having a large intersection angle with the bent portion is smaller than the load transmitted to the extending portion having a small intersection angle with the bent portion. . For this reason, the transmission efficiency at the time of transmitting the load input to one side member to the other side member is not good.

  An object of the present invention is to obtain a vehicle body lower structure that can improve the transmission efficiency when a load input to one front side member is transmitted to the other front side member in consideration of the above fact.

The present invention according to claim 1 is a bent portion inclined from the front in the vehicle width direction to the rear in the vehicle width direction, and an extension extending from the rear end portion of the bent portion to the rear of the vehicle body along the floor tunnel portion. A pair of left and right side members having a portion;
A connecting member that connects the rear ends of the bent portions of the pair of left and right side members;
A vehicle body lower structure having
The shape of the connecting member in plan view is an X shape.

  Therefore, when a load is applied to the side member from the front of the vehicle body at the front of the vehicle, this load is transmitted along the bent portion inclined from the front in the vehicle width direction to the rear in the vehicle width direction, In the end portion, it is distributed into an extending portion extending rearward of the vehicle body along the floor tunnel portion and a connecting member that connects the rear end portions of the bent portions of the pair of left and right side members. At this time, since the shape of the connecting member in plan view is an X shape, the crossing angle between the bent portion and the connecting member becomes larger than when the linear connecting member is arranged along the vehicle width direction. As a result, the load transmitted to the connecting member increases. That is, the front side member can be supported in the axial direction. For this reason, the transmission efficiency at the time of transmitting the load input into one side member to the other side member can be improved.

  The present invention according to claim 1 includes a bent portion inclined from the front in the vehicle width direction to the rear in the vehicle width direction, and an extending portion extending from the rear end portion of the bent portion to the rear of the vehicle body along the floor tunnel portion. And a connecting member that connects the rear ends of the bent portions of the pair of left and right side members to each other, and the shape of the connecting member in plan view is an X shape Therefore, there is an excellent effect that the transmission efficiency when the load input to one front side member is transmitted to the other front side member can be improved.

  A first embodiment of a lower body structure of the present invention will be described with reference to FIGS.

  In the figure, the arrow FR indicates the vehicle body front direction, the arrow UP indicates the vehicle body upward direction, and the arrow IN indicates the vehicle width inside direction.

  As shown in FIG. 2, a front side member 12 as a pair of left and right side members is disposed in the front portion of the vehicle body 10 of the present embodiment in the vicinity of the lower portions at both ends in the vehicle width direction along the vehicle body longitudinal direction. The front portion 12A of the front side member 12 has a closed cross-sectional structure extending in the longitudinal direction of the vehicle body, and a bent portion 12B formed on the vehicle body rear side of the front portion 12A of the front side member 12 is a front wall portion of the dash panel 14. Inclined from the upper front side of the vehicle body to the lower rear side of the vehicle body in a side view along the lower part of 14A.

  As shown in FIG. 1, in a plan view, the bent portions 12B of the pair of left and right front side members 12 are inclined from the front in the vehicle width direction to the rear in the vehicle width direction, respectively, and the rear end portion 12C of the bent portion 12B. From there, an extending portion 12 </ b> D extending rearward of the vehicle body is formed along the floor tunnel portion 16.

  Further, rear end portions 12C of the bent portion 12B of the pair of left and right front side members 12 are connected by an engine rear support member 20 as a connecting member, and the plan view shape of the engine rear support member 20 is an X shape. Yes.

  The vehicle body left front end portion 20A of the engine rear support member 20 is connected to the rear end portion 12C of the bent portion 12B of the front side member 12 on the left side of the vehicle body, and the vehicle body right rear end portion 20B of the engine rear support member 20 is It is connected to the extending portion 12D of the front side member 12 on the right side of the vehicle body. Further, the vehicle body right front end 20C of the engine rear support member 20 is connected to the rear end 12C of the bent portion 12B of the front side member 12 on the right side of the vehicle, and the vehicle rear left end 20D of the engine rear support member 20 is connected. Is connected to the extending portion 12D of the front side member 12 on the left side of the vehicle body.

  Accordingly, the axis L1 of the bent portion 12B of the front side member 12 and the axis L2 of the engine rear support member 20 extending from the left front end 20A to the right rear end 20B or from the right front end 20C to the left rear end 20D. The intersection angle θ1 is larger than that in the case where the linear engine rear support member 20 is disposed along the vehicle width direction. That is, the axis line L1 and the axis line L2 are close to a straight line.

  As shown in FIG. 3, the cross-sectional shape of the extending portion 12D of the front side member 12 viewed from the front-rear direction of the vehicle body is a hat shape with the opening portion directed upward of the vehicle body, and a flange 12F formed at the opening end portion. Is joined to the lower surface 14 </ b> A of the dash panel 14 and the inner side surface 16 </ b> B in the vehicle width direction of the side wall portion 16 </ b> A of the floor tunnel portion 16.

  Further, the left front end 20A, the right rear end 20B, the right front end 20C and the left rear end 20D of the engine rear support member 20 are fixed to the front side member 12 by fixing members 23 such as bolts and nuts, respectively. ing.

  As shown in FIG. 4, the engine rear support member 20 is made of steel having a cross-sectional hat shape, for example.

  The engine rear support member 20 is not limited to steel having a cross-sectional hat shape, and may be other configurations such as aluminum having ribs 21 formed in the cross-sectional hat shape as shown in FIG.

  As shown in FIG. 1, the front end portion 12E of the bent portion 12B of the front side member 12 and the vicinity of the front end portion 22A of the rocker 22 are connected by a torque box 24. The torque box 24 is a vehicle in plan view. The vehicle is inclined from the front in the width direction to the rear in the vehicle width direction.

  A rear portion 32A of the transmission 32 disposed at the rear portion of the engine 30 is disposed on the vehicle rear side of the engine rear support member 20.

  Next, the operation of this embodiment will be described.

  In the present embodiment, when a load (arrow F in FIG. 1) acts on the front side member 12 from the front of the vehicle body at the time of a frontal collision of the vehicle, the load F is inclined from the front in the vehicle width direction to the rear in the vehicle width direction. Are transmitted along the bent portion 12B of the front side member 12, and at the rear end portion 12C of the bent portion 12B, an extended portion 12D extending rearward of the vehicle body along the floor tunnel portion 16 and a pair of left and right front sides The rear end portion 12C of the bent portion 12B of the member 12 is distributed to the engine rear support member 20 that couples each other.

  At this time, in the present embodiment, since the plan view shape of the engine rear support member 20 is an X shape, from the axis L1 of the bent portion 12B of the front side member 12 and the vehicle body left front end portion 20A of the engine rear support member 20. The intersection angle θ1 with the axis L2 extending from the vehicle body right rear end portion 20B or the vehicle body right front end portion 20C to the vehicle body rear left end portion 20D has a linear engine rear support member disposed along the vehicle width direction. Compared to larger.

  As a result, in this embodiment, the load transmitted to the engine rear support member 20 increases. For this reason, the transmission efficiency at the time of transmitting the load input into one front side member 12 to the other front side member 12 can be improved.

  Note that the load transmitted from one front side member 12 to the other front side member 12 can be further increased by further increasing the crossing angle θ1.

  In the present embodiment, a part of the load input to the front side member 12 is transferred to the front end portion 12E of the bent portion 12B by the torque box 24 inclined from the vehicle width direction inner front to the vehicle width direction rear rear in plan view. To the vicinity of the front end 22 </ b> A of the rocker 22. For this reason, the load input to the front side member 12 can be distributed also to the rocker 22.

  Next, a second embodiment of the lower body structure of the present invention will be described with reference to FIGS.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 6, in this embodiment, the front side member 12 includes a front portion 12A, a portion 12G rearward from the mounting portion of the engine rear support member 20 in the extending portion 12D, a bent portion 12B, and an extending portion. Torque box according to the first embodiment for connecting the front portion 12E of the bent portion 12B of the front side member 12 and the vicinity of the front end portion 22A of the rocker 22 to the front portion 12H from the mounting portion of the engine rear support member 20 in 12D. It is divided into three parts, that is, an intermediate part 12K in which branch parts 12J as 24 parts are integrated.

  As shown in FIG. 7, the front end portion 12L of the intermediate portion 12K of the front side member 12 is connected to the rear end portion of the front portion 12A of the front side member 12, and the rear end of the intermediate portion 12K of the front side member 12 The portion 12M is connected to the front end portion of the portion 12G behind the mounting portion of the engine rear support member 20 in the extending portion 12D. Further, the vehicle width direction outer side end portion 12N of the intermediate portion 12K of the front side member 12 is connected to the vicinity of the front end portion 22A of the rocker 22.

  Next, the operation of this embodiment will be described.

  In the present embodiment, when a load (arrow F in FIG. 6) acts on the front side member 12 from the front of the vehicle body at the time of a vehicle frontal collision, the load F is inclined from the front in the vehicle width direction to the rear in the vehicle width direction. Are transmitted along the bent portion 12B of the front side member 12 and extended at the rear end portion 12C of the bent portion 12B along the floor tunnel portion 16 to the rear of the vehicle body, and a pair of left and right front sides The rear end portion 12C of the bent portion 12B of the member 12 is distributed to the engine rear support member 20 that couples each other.

  At this time, in the present embodiment, the vehicle rear plan view of the engine rear support member 20 is X-shaped, so that the axis L1 of the bent portion 12B of the front side member 12 and the vehicle body left front end 20A of the engine rear support member 20 are included. When the linear engine rear support member is disposed along the vehicle width direction, the intersection angle θ1 with the axis L2 extending from the vehicle body right rear end 20B or the vehicle right front end 20C to the vehicle left rear end 20D Larger than

  As a result, in this embodiment, the load transmitted to the engine rear support member 20 increases. For this reason, the transmission efficiency at the time of transmitting the load input to one front side member 12 to the other front side member 12 can be improved.

  Note that the load transmitted from one front side member 12 to the other front side member 12 can be further increased by further increasing the crossing angle θ1.

  Further, in the present embodiment, a part of the load input to the front side member 12 is bent by the branch portion 12J of the front side member 12 that is inclined from the vehicle width direction inner front to the vehicle width direction rear rear in the vehicle body plan view. Transmission from the front end 12E of the portion 12B to the vicinity of the front end 22A of the rocker 22 is possible. For this reason, the load input to the front side member 12 can be distributed also to the rocker 22.

  In the present embodiment, the bent portion 12B of the front side member 12 and the branch portion 12J that is the portion of the torque box 24 in the first embodiment are integrated, so that the bent portion 12B of the front side member 12 and the torque box 24 The load distribution is further improved because it is affected by the welding strength and rigidity of the steel and the connecting structure. Further, since the ridge line of the branch portion 12J of the front side member 12 passes smoothly between the front side member 12 and the rocker 22, the load distribution is further improved in this respect.

  As shown in FIG. 8, in the cross section of the intermediate portion 12K of the front side member 12, the vehicle width direction outer side portion 12P of the front end portion 12E of the bent portion 12B, the vehicle width direction outer side portion 12Q of the bent portion 12B, As shown in FIG. 9, the lower flange 40A of the bulkhead 40 is disposed on the lower wall portion 12S of the intermediate portion 12K of the front side member 12, and the upper flange 40B of the bulkhead 40 is disposed on the dash. It is good also as a structure which obstruct | occluded the vehicle width direction inner side edge part 12R of the branch part 12J with the bulkhead 40 by joining to 14B of the panel 14. FIG.

  In the case of this configuration, the bulkhead 40 can transmit a larger load F from the front of the vehicle body to the bent portion 12B side than the branch portion 12J, and the distributed load can be controlled. Bending strength can be greatly improved.

  Further, as shown in FIG. 10, a suspension member mounting portion 40C is formed on the lower flange 40A of the bulkhead 40, and a suspension member mounting portion 12T is formed on the lower wall portion 12S of the intermediate portion 12K of the front side member 12. As shown in FIG. 11, the front suspension member 44 may be fixed to the suspension member mounting portion 12T and the suspension member mounting portion 40C from below the vehicle body by bolts 46 and suspension member mounting nuts 48. The suspension member mounting nut 48 is joined to the vertical wall portion 40C of the bulkhead 40 and the vertical wall portion 12U of the front side member 12 by a bracket 50.

  In the case of this configuration, it is possible to improve the transmission efficiency when the load input to one front side member 12 is transmitted to the other front side member 12 via the front suspension member 44 at the time of a vehicle body collision.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, the cross-sectional shapes of the front side member 12 and the left and right rockers 22 are not limited to the cross-sectional shape of the above-described embodiment.

It is a plane sectional view showing the lower body structure concerning a 1st embodiment of the present invention. It is the perspective view seen from the vehicle body slanting back upper side which shows the vehicle body lower part structure concerning 1st Embodiment of this invention. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 1. It is the perspective view seen from the vehicle body slanting front lower side which shows the engine rear support member of the vehicle body lower part structure concerning 1st Embodiment of this invention. It is the perspective view seen from the vehicle body slant front lower side which shows the engine rear support member of the vehicle body lower part structure which concerns on the modification of 1st Embodiment of this invention. It is a plane sectional view showing the lower body structure concerning a 2nd embodiment of the present invention. It is the perspective view seen from the vehicle body diagonally rear upper side which shows a part of vehicle body lower part structure concerning 2nd Embodiment of this invention. It is the perspective view seen from the vehicle body diagonally rear upper side which shows a part of vehicle body lower part structure concerning the modification of 2nd Embodiment of this invention. FIG. 9 is an enlarged cross-sectional view taken along line 9-9 in FIG. It is the disassembled perspective view seen from the vehicle body diagonally rear upper side which shows a part of vehicle body lower part structure concerning the modification of 2nd Embodiment of this invention. It is a sectional side view which shows a part of vehicle body lower part structure concerning the modification of 2nd Embodiment of this invention.

Explanation of symbols

12 Front side member (side member)
12A Front part of front side member 12B Bent part of front side member 12C Rear end part of bent part of front side member 12D Extension part of front side member 14 Dash panel 16 Floor tunnel part 20 Engine rear support member (connecting member)
22 Rocker 24 Torque box 32 Transmission

Claims (1)

A pair of left and right side members having a bent portion that is inclined from the front in the vehicle width direction to the rear in the vehicle width direction, and an extending portion that extends from the rear end portion of the bent portion to the rear of the vehicle body along the floor tunnel portion. When,
A connecting member that connects the rear ends of the bent portions of the pair of left and right side members;
A vehicle body lower structure having
A vehicle body lower part structure, wherein the connecting member has an X shape in a plan view.

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