JP2000289651A - Front body structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front body structure of a vehicle capable of obtaining stable collision performance while preventing the generation of breakage where a relief recessed part is formed at a front side member. SOLUTION: This front body structure of a vehicle is provided with an engine unit 10 which is elastically-supported by mount brackets 27, 37 bolted to a front side member 2 between right and left front side members 2, 2 extending in the vehicle front/rear direction and having a closed-section shape, wherein the mount brackets 27, 37 are bridge-disposed in the vehicle front/rear direction and tightly-secured by bolts 28, 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front vehicle body structure of an automobile having a left and right front side member formed with a recess for avoiding interference with a front wheel.

[0002]

2. Description of the Related Art In order to enhance the energy absorption capacity of a vehicle at the time of a head-on collision, it is effective to increase the cross-sectional area of the front side member as much as possible and to make the side member straight in the front-rear direction. .

As shown in FIG. 7, to increase the cross-sectional area of the front side member 50, the sectional height and the sectional width w of the front side member 50 must be increased. There is a limit in increasing the cross-sectional width w because it is regulated by the tire envelope region 51 formed by steering the front wheels arranged on the outside and by the engine unit 52 on the inside.

On the other hand, as shown in FIG. 8, a cross-sectional width w of the front side member 53 is formed large, and an escape recess 53a (depth) is formed on the outer wall of the front side member 53 to avoid interference with the envelope area 51 of the tire. W1) may be formed. Also, in order to increase the cross-sectional width, there is a case in which a counterbore (escape recess) for avoiding interference with the engine unit is formed on the inner wall of the front side member (Japanese Patent Application Laid-Open No. 10-1998).
No. 7024). However, there is a problem that simply forming the escape concave portion causes the escape concave portion to be a breakpoint at the time of a head-on collision, so that the front side member is easily broken.

In order to prevent the escape recess from being broken, the above-mentioned publication discloses a fragile portion formed at the front of the front side member so as to be bent outward in the vehicle width direction at the time of a frontal collision.
There has been proposed a structure in which the inner side is prevented from breaking at the undercut.

[0006]

However, in the structure in which the front portion of the front side member is bent outward in the vehicle width direction to prevent the front side member from breaking at the undercut portion as described in the above-mentioned prior art, There is a concern that the bending mode in the axial direction becomes complicated and stable collision performance cannot be obtained.

Here, in order to increase the rigidity of the escape recess,
It is conceivable to increase the gauge or add a reinforcing member separately. However, in this case, there arises a problem that the weight and the number of parts increase.

On the other hand, from the viewpoint of increasing the rigidity of the mounting portion of the mounting bracket of the front side member, a reinforcing pipe is disposed in the side member, and the mounting bracket is fixed together with the reinforcing pipe by the bolt inserted into the pipe. It is conceivable to fix together. In this case, the reinforcing pipe is bridged between the upper and lower walls of the front side member and joined by arc welding.

However, if the reinforcing pipe is arc-welded to the side member, it is difficult to carry out this welding operation on the current front side member manufacturing line, and the rigidity of the mounting bracket mounting portion is increased. The above measures have been requested.

The present invention has been made in view of such circumstances, and provides a front body structure of an automobile which can obtain stable collision performance while preventing breakage when forming a recess in the front side member. It is intended to be.

[0011]

According to a first aspect of the present invention, an engine unit is disposed between left and right front side members having a closed cross section and extending in a vehicle front-rear direction, and the engine unit is connected to the front side. In a vehicle front body structure elastically supported by members via a mount bracket, a front wheel disposed on the outer wall of the left and right front side members on the outer side in the vehicle width direction of the front side members is provided at the time of steering. A relief recess for avoiding interference with the front side member is formed, and the mount bracket is arranged and fixed so as to function as a reinforcing member for the relief recess.

According to a second aspect of the present invention, in the first aspect, a reinforcing member formed by welding and joining the reinforcing pipe to a sheet metal reinforcement is attached to the front side member before and after the escape recess. In addition to arranging the side members so as to contact the inner surfaces of the upper and lower side walls,
The reinforcement is welded and fixed to the inner surface of the front side member, and the mount bracket is placed on the upper wall upper surface or the lower wall lower surface of the front side member and tightened to the front side member with a bolt inserted into the reinforcing pipe. It is characterized by being fixed.

[0013]

According to the front body structure of the automobile according to the present invention, for example, the mount bracket is elastically supported by the engine unit so as to function as a reinforcing member for the recessed recess of the front side member. If the front and rear portions of the escape recess are fixed by bolts before and after the escape recess and fixed with bolts, the front and rear portions of the escape recess are connected by a high-rigidity mounting bracket. Can be prevented from breaking at the escape recess. As a result, it is possible to eliminate a break point when the escape recess is formed in the front side member, to increase the cross-sectional width of the front side member, to increase the proof stress, and to improve the energy absorption performance at the time of a collision. There is.

Since the escape recess is reinforced by the mount bracket, the bending mode is more stable than the conventional one in which the break of the undercut is canceled by the fragile portion formed at the front of the front side member. Thus, the impact absorption performance at the time of collision can be improved from this point.
Further, it is not necessary to add a gauge or a rein hose to increase the rigidity, and it is possible to avoid an increase in weight and the number of parts.

According to the second aspect of the present invention, the reinforcing member in which the reinforcing pipe is joined to the reinforcement in advance by welding is assembled in the front side member by welding the reinforcement to the inner wall of the side member. The above-mentioned reinforcement can be assembled at the same time in the member assembling process, so that the present production line can be established. As a result, the rigidity of the mounting portion of the mounting bracket of the front side member can be improved,
The breakage of the escape recess can be more reliably prevented. In addition, the reinforcement can function as a bulkhead, and in this regard, the rigidity of the escape recess can be increased.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 6 are views for explaining a front body structure of an automobile according to an embodiment of the present invention, and FIGS. 1 to 3 are a plan view, a front view, and a side view, respectively, of the front body of the automobile. , FIGS. 4 and 5 are a plan view and a partial cross-sectional front view of the front side member, and FIG.
It is a perspective view of the attachment state of the reinforcement. The left, right, front and rear of the present embodiment are the left and right as viewed from the rear of the vehicle.
Before and after.

In FIG. 1, reference numeral 1 denotes a front body of an automobile. The front body 1 has a cross member 3 extending in the vehicle width direction between left and right front side members 2 extending in the vehicle longitudinal direction. It is of a schematic structure. In each of the front side members 2, a strip-shaped outer member 5 is disposed on a side member main body 4 having a hat-shaped cross section with an opening facing outward in the vehicle width direction. The flanges 4b and 5b have a structure in which the flanges 4b and 5b are joined to each other by spot welding, thereby forming a rectangular closed cross section.

The front side member 2 comprises a linear front half 2a and a rear half 2b which is connected to the front half 2a so as to be offset inward in the vehicle width direction, and the rear half 2b is formed by the front half 2a. From diagonally downward. A suspension tower 6 is joined to a rear portion of the left and right front half portions 2a, and an apron member 7 extending in the vehicle front-rear direction is joined to an outer end of the suspension tower 6.

A plurality of beads 2c are formed in the front half 2a of the side member 2 at predetermined intervals in the axial direction. The bead 2c induces axial compression deformation of the side member 2 at the time of a frontal collision.

A front wheel (not shown) is disposed on the outside of each front side member 2 in the vehicle width direction so as to be steerable left and right, and the front wheels are supported by the suspension tower 6 via struts. The sectional width w of the front half 2a of the front side member 2 is set large.
A relief recess 2d (depth W1) is formed on the outer wall of each front half 2a to avoid interference with the tire envelope a due to left and right steering of the front wheels. The escape recess 2d is formed by bending the upper wall 4c and the lower wall 4d of the outer member 5 and the side member body 4 inward.

An engine unit 10 is mounted between the left and right side members 2. The engine unit 10 has a structure in which a transmission case 12 is integrally connected to a side wall in a vehicle width direction of a horizontally mounted engine 11 in which a crankshaft 11a is horizontally oriented in a vehicle width direction.

The engine unit 10 includes a left side wall 12 a of the transmission case 12 and a right side wall 11 of the engine 11.
c, and the first, second, and third mount members 1 disposed at the center of the rear wall 11b of the engine 11 in the vehicle width direction.
It is elastically supported by the front vehicle body 1 via 5, 16 and 17. The first to third mount members 15 to 17 have the same structure, and are fixed by baking by inserting the inner cylinder 19 with the elastic member 20 interposed in the axis of the outer cylinder 18.

The third mount member 17 is arranged with its axis oriented in the vehicle width direction, and the inner cylinder 19 of the mount member 17 has a U-shaped engine which is bolted and fixed to the rear wall 11b of the engine 11. It is fixed to the bracket 23 by bolts 24. Further, the third mount member 1
The outer cylinder 18 is fixed to the cross member 3 by bolts via a mount bracket 22.

The first mount member 15 is disposed with its axis oriented in the longitudinal direction of the vehicle body.
Reference numeral 9 denotes a U-shaped engine bracket 25, which is bolted and fixed to the left side wall 12a of the transmission case 12, and is tightened and fixed by bolts 26.

A mount bracket 27 is joined to the outer cylinder 18 of the first mount member 15 by welding.
The mount bracket 27 is provided on the lower surface of the lower wall 4d of the left front side member 2 with a pair of front and rear bolts 28, 28.
It is fastened and fixed.

A reinforcing member 30 is provided in the front side member 2. The reinforcing member 30 is formed by integrally connecting a steel pipe reinforcing pipe 31 to a sheet metal reinforcement 32. This reinforcement 32
Are a horizontal piece 32a which abuts on the inner surface of the vertical wall 4e of the side member body 4, a vertical piece 32b which bends and extends in the vehicle width direction following the horizontal piece 32a, and is provided on both upper and lower ends of the vertical piece 32b. Subsequently, the upper wall 4c and the lower wall 4 of the side member body 4 are bent and extended.
d and an upper piece 32c and a lower piece 32d that abut against the vertical wall 4e of the side member body 4.
Are joined by spot welding. Note that 32f,
32f is a lightening hole.

The reinforcing pipe 31 is disposed so as to bridge between the upper piece 32c and the lower piece 32d. The peripheral edges of both ends of the reinforcing pipe 31 are joined to the upper and lower pieces 32c and 32d by arc welding. I have. Here, the reinforcing member 30
Is used to join the reinforcing pipe 31 to the reinforcement 32 in advance by arc welding, and when the outer member 5 is spot-welded to the side member main body 4 in the side member 2 manufacturing process, the horizontal piece 32a of the reinforcement 32 is It is assembled by spot welding to the vertical wall 4e of the member main body 4.

Each of the reinforcing members 30 is connected to each of the bolts 28 of the mount bracket 27 in the front side member 2.
The mounting bracket 27 is fixed to the side member 2 together with the reinforcing pipe 31 by the bolt 28 inserted into the reinforcing pipe 31.

In a plan view, the mount bracket 27 of the first mount member 15 is disposed on the lower surface of the right front side member 2 so as to extend over the clearance recess 2d in the longitudinal direction of the vehicle body. The bolts 28 and the reinforcing members 30 are located at the front and rear of the escape recess 2d. Thus, the mount bracket 27 functions as a reinforcing member for the escape recess 2d.

The second mount member 16 is arranged with its axis oriented in the up-down direction, and is arranged slightly offset in front of the vehicle with respect to the first mount member 15 when viewed from a plane. At the upper end of the inner cylinder 19 of the mount member 16, a hook-shaped engine bracket 35 which is bolted and fixed to the right side wall 11 c of the engine 11 is bolted and fixed.

The outer cylinder 18 of the second mount member 16
A pair of front and rear mount brackets 37, 37 are joined by welding. Each mount bracket 37 is fastened and fixed to the upper surface of the upper wall 4c of the right front side member 2 by a pair of front and rear bolts 38,38. A reinforcing member 30 having the same structure as that described above is provided in the front side member 2, and the mount bracket 37 is fixedly fastened to the front side member 2 together with the reinforcing pipe 31 by each bolt 38.

In plan view, the mount brackets 37 of the second mount member 16 are arranged so as to extend over the clearance recess 2d of the left front side member 2 in the vehicle longitudinal direction. The bolts 38 and the reinforcing members 30 are located at the front and rear of the recess 2d. Thus, the mount bracket 37 functions as a reinforcing member for the escape recess 2d.

Next, the operation and effect of this embodiment will be described. According to the present embodiment, the mount brackets 27 and 37 are arranged in the escape recesses 2d of the left and right front side members 2 and 2 in such a manner as to extend in the vehicle front-rear direction, and are fastened and fixed by the bolts 28 and 38. ,
Each recess 2d has a rigid mounting bracket 27,
37 connects the bridge in the front-rear direction of the vehicle, so that the escape recess 2d can be reliably prevented from being broken by a frontal collision of the vehicle. As a result, it is possible to eliminate a break when the recess 2 d is formed in the front side member 2, to increase the cross-sectional width w of the front side member 2 by w1, and to improve the proof stress accordingly, Energy absorption performance at the time can be improved.

Further, since the mounting brackets 27 and 37 are fixed to the left and right clearance recesses 2d by bridging the mounting recesses 2d, the structure is more stable than the conventional structure in which the bend of the undercut is canceled by the fragile portion of the front side member. A bending mode is obtained, and the collision performance can be improved from this point as well. Further, it is not necessary to add a gauge or a rein hose to increase the rigidity, and it is possible to avoid an increase in weight and the number of parts.

In this embodiment, the reinforcing pipe 31 is arc welded to the reinforcement 32 in advance, and the reinforcement 32 is assembled in the process of assembling the front side member 2.
Was spot-welded to the side member 2, so that the reinforcement 3 was assembled in the process of assembling the front side member 2.
2 can be assembled at the same time, and it can be realized in the current production line. As a result, the rigidity of the mounting portions of the mount brackets 27 and 37 of the front side member 2 can be improved, the breakage of the escape recess 2d can be more reliably prevented, and the collision performance can be further improved. In addition, since the reinforcement 32 functions as a bulkhead, the rigidity of the relief recess 2d can be increased.

In the above embodiment, the case where the escape recess 2d for preventing interference with the tire envelope a of the front wheel is formed on the outer wall of the front side member 2 is described as an example. The present invention can also be applied to a case where an escape recess is formed on the inner wall to avoid interference with the engine unit. In this case as well, the same effect as in the above embodiment can be obtained by bridging and connecting the mount bracket to the escape recess.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a front body structure of an automobile according to an embodiment of the present invention.

FIG. 2 is a front view of the front vehicle body.

FIG. 3 is a side view of the front vehicle body.

FIG. 4 is a plan view of a right front side member of the front vehicle body.

FIG. 5 is a sectional view of a mounting portion of the right front side member.

FIG. 6 is a perspective view of a reinforcing member provided on the mount portion.

FIG. 7 is a schematic plan view of a conventional front vehicle body.

FIG. 8 is a schematic plan view of a conventional front vehicle body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front body 2 Front side member 2d Escape recess 10 Engine unit 27, 37 Mount bracket 28, 38 Bolt 30 Reinforcement member 31 Reinforcement pipe 32 Reinforcement

Claims (2)

[Claims] 1. An automobile in which an engine unit is arranged between left and right front side members having a closed cross section and extending in the front-rear direction of the vehicle, and the engine unit is elastically supported by the front side members via a mount bracket. In the front vehicle body structure described above, a relief is provided on the outer walls of the left and right front side members to prevent front wheels disposed outside the front side members in the vehicle width direction from interfering with the front side members during steering. A front body structure of an automobile, wherein a recess is formed, and the mount bracket is arranged and fixed so as to function as a reinforcing member for the escape recess. 2. A reinforcing member formed by welding a reinforcing pipe to a sheet metal reinforcement as set forth in claim 1, wherein the reinforcing pipe is provided on the front side member before and after the escape recess in the front side member. While arranging so as to be in contact with the inner surface of the lower side wall, the reinforcement is welded and fixed to the inner surface of the front side member, and the mount bracket is mounted on the upper side wall upper surface or the lower side wall lower surface of the front side member, A front vehicle body structure for an automobile, wherein the vehicle body is fastened and fixed to a front side member with a bolt inserted through the reinforcing pipe.