JPH05185955A - Car front body structure - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a front body structure of an automobile capable of lengthening a crash stroke and ensuring a sufficient amount of energy absorption. [Structure] A pair of front side members 12 are provided in the vicinity of a vehicle width direction outer lower portion of a front portion 10A of a vehicle body 10 along a vehicle body front-rear direction, and from a bumper reinforcement 13 provided at a front end portion of the front side member 12. A connecting member 30 is provided at a position away from the rear by a predetermined distance L2, and a front cross member 20 extending in the vehicle width direction is attached to the connecting member 30 with a bolt 54. With this, bumper force 13 and
The crash stroke L2 between the front side member 12 and the front cross member mounting portion is longer than the conventional crash stroke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile front body structure, and more particularly to an automobile front body structure in a connecting portion between a front side member and a front cross member.

[0002]

2. Description of the Related Art Conventionally, as an example of an automobile front body structure, Japanese Utility Model Laid-Open No. 2-288 is known.

As shown in FIG. 6, in a front body structure 70 for an automobile, a pair of front side members 72 extending in the front-rear direction of the vehicle body are provided near the lower portions of both ends in the vehicle width direction at the front portion of the vehicle body. A front cross member 74 is installed on the front side member 72. The front cross member 74 has a closed cross-sectional structure extending in the vehicle width direction, and has both end portions 74A and 74B.
Are welded to the lower surfaces of the pair of front side members 72, respectively.

[0004]

However, in this vehicle front body structure, the front cross member 74 is welded to the pair of front side members 72, and then the engine is assembled into the engine room from below the vehicle body. Therefore, in order to prevent the engine from interfering with the front cross member 74 when the engine is assembled, the front cross member 74 is arranged at a position in front of the engine 76, for example, near the lower front side of the radiator support 78, as shown in FIG. Has been done. That is, as shown in FIG. 6, the front cross member 74 is fixed near the front end portion 72A of the front side member 72.

Therefore, the rigidity of the connecting region 72B (the hatched region in FIG. 6) of the front side member 72 with the front cross member 74 is high, and the load acts from the front of the vehicle body (direction of arrow F in FIG. 6). In this case, the connecting region 72B of the front side member 72 with the front cross member 74 does not buckle, and the portion 72C of the front side member 72 on the rear side of the front cross member 74 is seated as shown by an imaginary line in FIG. Bends easily and is stable and difficult to axially compress and deform.

That is, in the front side member 72, the portion which is stably axially compressed and deformed to form a so-called crash stroke is the front surface 8 of the bumper reinforcement 80.
0A and the front end of the front side member 72 at the front end of the front cross member attachment portion (the range of arrow L1 in FIG. 6), the crash stroke L1 of the front side member 72 is not sufficient, and a sufficient amount of energy absorption is secured. hard.

In view of the above facts, an object of the present invention is to obtain a front body structure of an automobile which can prolong a crash stroke and secure a sufficient energy absorption amount.

[0008]

According to a first aspect of the present invention, there is provided a front body structure for an automobile, comprising: a pair of front side members provided along a vehicle front-rear direction in the vicinity of a vehicle width direction outer lower portion of a vehicle body front portion. A front body structure of an automobile having a front cross member erected on the pair of front side members, and a bumper reinforcement arranged in front of the pair of front side members along a vehicle width direction, The front cross member is arranged below the engine, and the front cross member is fixed to the pair of front side members at the same time as the engine is assembled or after the engine is assembled.

[0009]

In the vehicle front body structure according to the first aspect of the present invention, the front cross member is attached to the front side member at the same time as the engine assembly or after the engine assembly.
For example, by fixing with bolts, the front cross member can be arranged below the engine. Therefore, when the engine is assembled, the engine does not interfere with the front cross member, and the connecting position of the front cross member to the front side member can be moved rearward in the vehicle front-rear direction as compared with the conventional structure.

Therefore, the portion between the front surface of the bumper reinforcement and the front end of the front cross member mounting portion of the front side member, that is, the crush stroke is longer than that of the conventional structure, and when a load is applied from the front of the vehicle body,
A stable amount of energy absorption can be secured by stably axially deforming this portion.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment of the Front Body Structure for a Car of the Present Invention
An embodiment will be described with reference to FIGS. In the figure, an arrow FR indicates a vehicle body front direction, an arrow UP indicates a vehicle body upward direction, and an arrow IN indicates a vehicle width inward direction.

As shown in FIG. 1, a pair of front side members 12 extending in the front-rear direction of the vehicle body are provided near the lower portions of both ends of the front portion 10A of the vehicle body 10 in the vehicle width direction. The front portion of the front side member 12 penetrates the radiator support 17, and
In front of, along the car width direction, bumper reinforcement 1
3 are arranged. A pair of crash boxes 1 are provided near both ends in the vehicle width direction of the bumper reinforcement 13.
5 are installed and these crash boxes 1
5, the bumper reinforcement 13 is connected to the front end portion 12A of the front side member 12.

As shown in FIG. 2, the front portion of the front side member 12 includes a front side member inner 14 which constitutes an inner portion of the front side member 12 in the vehicle width direction.
The front side member 12 is formed of a front side member outer 16 that constitutes an outer side portion of the front side member 12 in the vehicle width direction.
The front portion of the front side member inner 14 has a U-shaped cross section with the opening facing outward in the vehicle width direction, and the front end portion of the upper wall portion 14A of the front side member inner 14 extends downward in the vehicle body vertical direction. It is bent toward to form a flange 14B. Further, the front end of the lower wall portion 14C of the front side member inner 14 is bent upward in the vehicle body vertical direction to form a flange 14D. The front end portion of the vertical wall portion 14E of the front side member inner 14 is bent toward the inner side in the vehicle width direction to form a flange 14F, and the flange 14F is connected to the flange 14B and the flange 14D.

The front side member outer 16 has a flat plate shape, and the base portion 16A has a front side member 12.
Of the vehicle width direction outer side wall portion. An upper portion of the front side member outer 16 is bent outward in the vehicle width direction to form a flange 16B. This flange 16B is
It is welded to the lower surface of the outer side edge of the upper wall portion 14A of the front side member inner 14 in the vehicle width direction. Further, the lower portion of the front side member outer 16 is bent toward the inner side in the vehicle width direction to form a flange 16C.
6C is a lower wall portion 14 of the front side member inner 14.
It is welded to the lower surface of the outer edge portion of C in the vehicle width direction. A front end portion of the base portion 16A of the front side member outer 16 is bent inward in the vehicle width direction to form a flange 16D.

Therefore, the front side member 12 has a closed cross-section structure which extends in the front-rear direction of the vehicle body by the front side member inner 14 and the front side member outer 16. The rear end of the crush box 15 shown in FIG. 1 is coupled to the flanges 14B, 14D, 14F and 16D provided on the front end of the front side member 12.

As shown in FIG. 1, a front cross member 20 extending in the vehicle width direction is disposed below the front end portion 12A of the front side member 12 and at a position a predetermined distance rearward of the vehicle body.

As shown in FIG. 3, the position of the front cross member 20 is below the radiator support 17 and below the front end portion 21A of the engine 21.

As shown in FIG. 2, the front cross member 20 includes a front cross member upper 22 which constitutes an upper portion of the front cross member 20 and a front side member lower 2 which constitutes a lower portion of the front cross member 20.
4 and 4. Front cross member upper 2
2 has a U-shaped cross section with the opening facing downward in the vertical direction of the vehicle body, and the front side member lower 24 has a U-shaped cross section with the opening facing upward in the vertical direction of the vehicle body.
The upper edge of the front wall portion 24A of the front side member lower 24 is welded to the rear side of the lower end edge of the front wall portion 22A of the front cross member upper 22 in the vehicle front-rear direction. The upper edge of the rear wall portion 24B of the front side member lower 24 is welded to the front side of the lower edge portion of the wall portion 22B in the vehicle front-rear direction.

Therefore, the front cross member 20 has a closed cross-sectional structure extending in the vehicle width direction by the front cross member upper 22 and the front cross member under 24.

A pair of through holes 26 are formed near the outer side of the base portion 22C of the front cross member upper 22 in the vehicle width direction at intervals in the vehicle front-rear direction, and the base portion of the front cross member under 24 is formed. A pair of through holes 28 are formed coaxially with the pair of through holes 26 of the front cross member upper 22 near the vehicle width direction outer side portion of 24C.

As shown in FIG. 1, a connecting member 30 is provided between the front side member 12 and the front cross member 20, and the connecting member of the front side member 12 is connected to the front surface 13A of the bumper reinforcement 13. The distance between the mounting portions of 30 is L2. The connecting member 30 also includes two beam portions, a front beam portion 30A and a rear beam portion 30B, which are arranged in the vehicle body front-rear direction with a gap 31 therebetween.

As shown in FIG. 2, this connecting member 30
Is composed of a connecting member inner panel 32 forming an inner side portion of the connecting member 30 in the vehicle width direction and a connecting member outer panel 34 forming an outer side portion of the connecting member 30 in the vehicle width direction. The connecting member inner panel 32 connects a front portion 36 forming a part of the front beam portion 30A, a rear portion 38 forming a portion of the rear beam portion 30B, a lower portion of the front portion 36 and a lower portion of the rear portion 38. The bottom portion 40 is formed into a substantially V shape in a side view.

The front portion 36 includes a front wall portion 36A and an inner wall portion 36B.
The inner wall portion 36B extends upward in the vertical direction of the vehicle body to form an extension portion 36C. The extension portion 36C is welded to the inside of the vertical wall portion 14E of the front side member inner 14 in the vehicle width direction. There is. The rear portion 38 is composed of a rear wall portion 38A and an inner wall portion 38B. The inner wall portion 38B extends upward in the vehicle body vertical direction to form an extended portion 38C.
8C is a vertical wall portion 14E of the front side member inner 14.
It is welded to the inside of the car in the width direction. Also, the rear wall portion 38A
An upper end of the flange 38 is bent rearward in the vehicle front-rear direction.
This flange 38D is welded to the lower side of the lower wall portion 14C of the front side member inner 14 in the vehicle body vertical direction. The vehicle width direction outer side edge portion of the rear wall portion 38A is
A flange 38E is formed by being bent rearward in the vehicle body front-rear direction.

The bottom portion 40 has a bottom wall portion 40A continuous with the rear wall portion 38A of the rear portion 38, an inner wall portion 36B of the front portion 36 and an inner wall portion 40B of the rear portion 38.
The outer end portion of the bottom wall portion 40A in the vehicle width direction is bent downward in the vehicle body vertical direction to form a flange 40D.
Further, a pair of through holes are formed in the bottom wall portion 40A at intervals in the vehicle front-rear direction, and a pair of weld nuts 42 are welded to the upper side in the vehicle body vertical direction coaxially with these through holes. There is.

The connecting member outer panel 34 includes a front beam portion 30.
A substantially V shape in a side view, which includes a front portion 44 that forms a part of A, a rear portion 46 that forms a part of the rear beam portion 30B, and a bottom portion 48 that connects the lower portion of the front portion 44 and the lower portion of the rear portion 46. It is said that

The front portion 44 includes an outer wall portion 44A and a rear wall portion 44B.
The outer wall portion 44A is extended to the upper side in the vehicle body vertical direction to form an extended portion 44C, and this extended portion 44C is welded to the vehicle width direction outer side of the base portion 16A of the front side member outer 16. A front edge portion of the outer wall portion 44A is bent outward in the vehicle width direction to form a flange 44D, and a front upper end portion 50A of the hook 50 which is V-shaped in a side view is provided on the vehicle body front-rear direction rear side of the flange 44D. Is welded. Further, the vehicle width direction outer edge portion of the front wall portion 36A of the connecting member inner panel 32 is welded to the front side of the flange 44D in the vehicle front-rear direction.

The upper end portion of the rear wall portion 44B is bent rearward in the vehicle body front-rear direction to form a flange 44E. This flange 44E is the lower wall portion 1 of the front side member inner 14.
It is welded to the lower side of the vehicle body 4C in the vertical direction. Rear wall 44
An inner end portion of B in the vehicle width direction is bent rearward in the vehicle body front-rear direction to form a flange 44F. This flange 44F is welded to the outer side in the vehicle width direction of the inner wall portion 36B of the front portion 36 of the connecting member inner panel 32. ing.

The rear portion 46 includes an outer wall portion 46A and a front wall portion 46B.
The outer wall portion 46A is extended to the upper side in the vertical direction of the vehicle body to form an extended portion 46C, and this extended portion 46C is welded to the outside of the base portion 16A of the front side member outer 16 in the vehicle width direction. Further, a rear upper end portion 50B of the hook 50 is welded to the outside of the rear end edge portion of the outer wall portion 46A in the vehicle width direction, and the connecting member inner is provided inside the rear end edge portion of the outer wall portion 46A in the vehicle width direction. The flange 38E of the rear portion 38 of the panel 32 is welded.

The upper end portion of the rear wall portion 46B is bent forward in the vehicle front-rear direction to form a flange 46D, which is the lower wall portion 1 of the front side member inner 14.
It is welded to the lower side of the vehicle body 4C in the vertical direction. Rear wall 46
An inner end portion of B in the vehicle width direction is bent forward in the vehicle body front-rear direction to form a flange 46E, and this flange 46E is welded to the outer side in the vehicle width direction of the inner wall portion 38B of the rear portion 38 of the connecting member inner panel 32. ..

The bottom portion 48 is an outer wall portion 48A continuous with the outer wall portion 44A of the front portion 44 and the outer wall portion 46A of the rear portion 46.
And a rear wall portion 44B of the front portion 44 and a front wall portion 46B of the rear portion 46.
And a lower wall portion 48B that is continuous with the lower wall portion 48B. The vehicle width direction outer end portion of the lower wall portion 48B is bent upward in the vehicle body vertical direction to form a flange 48C that is continuous with the flange 44F and the flange 46F. ing. The flange 48C is welded to the outer side in the vehicle width direction of the inner wall portion 40B of the bottom portion 40 of the connecting member inner panel 32.

As shown in FIG. 1, bolts 54 are inserted into the through holes 28 and 26 of the front cross member 20 from below, and the leg portions 54A of these bolts 54 are
The weld nuts 42 of the connecting member 30 are screwed together. Therefore, the front cross member 20 is coupled to the front portion of the front side member 12 via the connecting member 30.

Next, the operation of this embodiment will be described. In the vehicle front body structure of this embodiment, the front cross member 20 is attached to the connecting member 30 fixed to the front side member 12 with the bolts 54 at the same time as the assembling of the engine 21 or after the assembling of the engine 21. The front cross member 20 can be arranged below the front end portion 21A of the engine 21. For this reason, when the engine is assembled, the engine 21 is
It is possible to move the connecting position of the front cross member 20 to the front side member 12 rearward in the front-rear direction of the vehicle body without interfering with the above.

Therefore, a portion between the front surface 13A of the bumper reinforcement 13 and the front end of the mounting portion of the connecting member 30 for fixing the front cross member of the front side member 12, that is, the crush stroke L2 is the conventional structure shown in FIG. Is longer than the crash stroke L1 and the load (arrow A in FIG. 1) acts from the front of the vehicle body,
A stable amount of energy absorption can be secured by stably axially deforming this portion.

Next, a second embodiment of the vehicle front body structure of the present invention will be described with reference to FIGS. The same members as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 5, in the present embodiment, a pair of crash boxes 60 connecting the bumper reinforcement 13 and the front side member 12 has a two-stage structure in the vehicle front-rear direction.

That is, as shown in FIG. 4, this embodiment has a structure in which the front portion of the front side member 12 from the radiator support 17 is replaced by the crash box 62 in the first embodiment. The crash box 62 has higher rigidity than the front crash box 15, and is configured to undergo axial compression deformation after completion of axial compression deformation of the crash box 15.

Therefore, in this embodiment as well, the portion which becomes the crash stroke L2 can be made longer than the conventional crash stroke L1, so that the same effect as in the first embodiment can be obtained, and the load from the front of the vehicle body (see FIG. Four
Crash box 1 when arrow A)
5, crash box 62, front side member 1
Since the axial compression deformation is performed in the order of 2, the energy of the load up to a certain magnitude is absorbed stepwise, and the front side member 1
2 It becomes easy to set up a crash box that does not damage the main unit.

[0038]

According to the present invention, the front cross member is arranged below the engine, and the front cross member is fixed to the pair of front side members at the same time as the engine is assembled or after the engine is assembled. It has an excellent effect that it can be lengthened and a sufficient energy absorption amount can be secured.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a front body structure of an automobile according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a main member of a front body structure for a vehicle according to an embodiment of the present invention, as viewed from the front inside the vehicle body.

FIG. 3 is a side sectional view of a vehicle width direction central portion showing a front body structure of an automobile according to the first embodiment of the present invention.

FIG. 4 is a side sectional view showing a front body structure of an automobile according to a second embodiment of the present invention.

FIG. 5 is an exploded perspective view of a front portion of a vehicle body to which a front body structure for an automobile according to a second embodiment of the present invention is applied, viewed from the front side of the vehicle body.

FIG. 6 is a side view showing a front body structure of a conventional automobile.

FIG. 7 is a side sectional view of a center portion in a vehicle width direction showing a front body structure of a conventional vehicle.

[Explanation of symbols]

 10 Body 12 Front Side Member 13 Bumper Reinforce 14 Front Side Member Inner 15 Crash Box 16 Front Side Member Outer 20 Front Cross Member 21 Engine 21A Front End 22 Front Cross Member Upper 24 Front Side Member Lower 30 Coupling Member 60 Crash Box 62 Crash Box

Claims (1)

[Claims] 1. A pair of front side members provided along a vehicle front-rear direction in the vicinity of a vehicle width direction outer lower portion of a vehicle body front portion, a front cross member erected on the pair of front side members, and the pair. A front body structure of an automobile having a bumper reinforcement arranged in front of a front side member of the vehicle along a vehicle width direction, the front cross member being arranged below an engine, and the front cross member being assembled to an engine. A front body structure for an automobile, which is fixed to the pair of front side members at the same time as or after the engine is assembled.