JP2009161107A - Front structure of vehicle body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a front structure of a vehicle body capable of suppressing the deformation of a dashboard lower part toward the inside of a cabin by absorbing a load through a steering gear box mounted on a front sub frame. <P>SOLUTION: In this front structure 11 of the vehicle body, the tilted rear parts 122 of front side frames 51, 52 arranged continuously forward are connected to an under body 23 which forms the floor of a cabin 22, the rear part (left rear end) 66 and the right rear end (rear part) 77 of the parallel cross front sub frame 15 are fastened to the tilted rear parts 122, and the long steering gear box 38 of a steering device 25 is mounted near the rear end (gear box mounting part) 77. An impact absorbing member 16 for absorbing impact by deforming when deformed and pushed rearward by the steering gear box at the frontal collision of a vehicle is arranged at the front wall part 126 of the tilted rear parts 122 which face the steering gear box 38. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle body front structure that absorbs an impact caused by a rearward displacement of a long steering gear box of a steering device in the event of a vehicle frontal collision.

In some vehicle body front structures, a long reinforcing member is attached to increase the holding strength of the long steering gear box of the steering device. The reinforcing member (dash cross member) is employed in the steering gear box arrangement structure, and is attached to the rear part of the left and right front side members located in the vicinity of the left and right wheels and a dash panel forming a partition wall with the engine room, and the steering gear. Since the box is supported, the holding strength of the steering gear box can be increased. Further, at the time of a frontal collision, the load can be distributed from the front side member to the reinforcing member (dash cross member) or the dash panel via the steering gear box (see, for example, Patent Document 1).
JP 2006-192940 A (page 11, FIG. 1)

However, the steering gear box arrangement structure of Patent Document 1 is limited to a structure in which the steering gear box is arranged at the upper rear ends of the left and right front side members. However, there is a problem that it cannot be adopted in a structure in which a steering gear box is arranged.
Further, the reinforcing member (dash cross member) is weak against the load applied from the front of the vehicle, and there is a problem that the load absorption is small even through the supporting steering gear box.

  The present invention has a structure in which even if a steering gear box is disposed on the front subframe, the load through the steering gearbox is absorbed, the deformation of the dashboard lower toward the vehicle interior is suppressed, and the front subframe is separated. However, it is an object of the present invention to provide a vehicle body front structure that absorbs a load via the steering gear box.

  According to the first aspect of the present invention, an inclined rear portion of a front side frame connected to the front is connected to an underbody that forms a floor of a passenger compartment, a rear portion of a cross-shaped front subframe is fastened to the inclined rear portion, and a steering device is disposed near the rear portion. In a vehicle body front structure where a long steering gear box is attached, if the steering gear box is displaced backward and pushed by the front collision of the vehicle against the front wall part of the inclined rear part facing the steering gear box, it will be deformed. An impact absorbing member that absorbs the impact is arranged.

  The invention according to claim 2 is characterized in that the shock absorbing member is disposed below in the case of a structure in which the front subframe is separated by an impact, compared to a structure in which the front subframe is not separated.

  In the invention according to claim 1, when the steering gear box is displaced and pushed rearward by a front collision of the vehicle on the front wall portion of the inclined rear portion of the front side frame facing the steering gear box, it is deformed and absorbs the shock. Since the shock absorbing member is arranged, the load applied from the steering gear box can be absorbed by the shock absorbing member even in the case of a frontal collision of the vehicle even if the vehicle is retracted together with the front girder-shaped front subframe on which the steering gear box is mounted. it can. Therefore, even if the steering gear box is arranged in the front subframe, there is an advantage that the load of the frontal collision through the steering gear box can be absorbed.

  Further, since the shock absorbing member suppresses the backward movement of the steering gear box, as a result, the deformation of the dashboard lower toward the vehicle interior can be suppressed.

  In the invention according to claim 2, the shock absorbing member is arranged below in the case of the structure in which the front subframe deviates due to an impact than in the case of the structure in which the front subframe does not deviate. Even if the vehicle moves backward, the steering gear box placed on the front sub-frame contacts the impact absorbing member. Therefore, even if the structure is such that the front subframe is separated, there is an advantage that the load of the frontal collision via the steering gear box can be absorbed.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a plan view for explaining the outline of the front body structure of the present invention.

  The vehicle body front structure 11 has a cross-beam shaped subframe (front subframe) 15 that supports the engine 13 and the front suspension 14 of the vehicle 12 and has an impact absorbing member 16. Details will be described later.

  The vehicle 12 includes a vehicle body 17. The vehicle body 17 has a front body 21 to which the engine 13 and the front suspension 14 are attached, an underbody 23 that forms the floor of the passenger compartment 22, and wheels 24 that are supported by the front suspension 14. And a steering device 25 for steering the vehicle.

  The front suspension 14 includes a spring 31, an upper arm 32, a lower arm (not shown), and a knuckle 33 whose upper and lower sides are respectively attached to the upper arm 32 and the lower arm.

  The steering device 25 is an electric power steering, and a steering wheel 35, a steering shaft 36, an electric motor 37, a steering gear box 38, a tie rod 41, and a tie rod that connects the tie rod 41 to the knuckle 33 of the front suspension 14. An end 42 and a steering detection unit (not shown) for detecting a steering state such as a steering angle are provided.

  The underbody 23 includes left and right floor frames 44, left and right side sills 45, and a dashboard lower 47 that forms a partition wall with the engine room 46 of the front body 21.

  FIG. 2 is a perspective view of the vehicle body front structure of the present invention, as viewed from below. This will be described with reference to FIG.

  The front body 21 has an arrow a1 from below on the left front side frame 51, the right front side frame 52, the left front side frame 51, and the right front side frame 52 located in the vicinity of the left and right wheels 24 from below. And the subframe 15 fastened by the fastening member 53 is provided.

  The sub-frame 15 includes a front beam member 56 disposed in front, a left beam member 57 and a right beam member 58 connected to the front beam member 56, and a rear beam member 61 connected to the left beam member 57 and the right beam member 58. The front beam member 56 is formed with a left front attachment portion 63 at one end and a right front attachment portion 64 at the other end, and is attached to the front fastening portion 65 of the left front side frame 51 and the right front side frame 52 with the fastening member 53, respectively. A left rear attachment portion 67 is formed at the left rear end (rear portion) 66 of the left beam member 57, and a right rear attachment portion 72 is formed at the right rear end (rear portion) 71 of the right beam member 58, respectively. The side frame 51 and the right front side frame 52 are attached to a rear fastening portion 73 with fastening members 53.

  The rear fastening portion 73 is provided at the rear portion of the left front side frame 51 and the right front side frame 52, but the provided portion is also near the boundary between the underbody 23 and the left and right floor frames 44 of the underbody 23, It can also be said that it was provided at the front part of the floor frame 44.

  A front engine mount member 75 on which the engine 13 is mounted is disposed at the center of the front beam member 56, and a rear engine mount member 76 on which the engine 13 is mounted is disposed at the center of the rear beam member 61. A gear box attaching portion 77 for attaching the steering gear box 38 of the steering device 25 is formed on the member 61, and a lower arm connecting portion 81 for connecting the front suspension 14 to the left beam member 57 and the right beam member 58 is formed. The springs 31 of the front suspension 14 are connected to damper housings (not shown) of the left front side frame 51 and the right front side frame 52, respectively.

  The front side frame 51 forms a rectangular tubular side frame main body 121, extends in the front-rear direction (Y-axis direction) of the vehicle 12, and is disposed substantially horizontally, and is an inclined rear portion at the rear end of the side frame main body 121. The side frame rear end 122 is joined by welding and joined to the dashboard lower 47 and the floor frame 44 of the underbody 23.

FIG. 3 is a perspective view of an inclined rear portion (side frame rear end) of the vehicle body front structure. This will be described with reference to FIG.
The side frame rear end (inclined rear portion) 122 has a groove shape and is formed with an inclined portion 124 that is inclined rearward and downward, and is connected to the inclined portion 124 to form a joining margin portion 125. The shock absorbing member 16 is attached to the center of the front wall portion 126 of the inclined portion 124 by welding.
The right front side frame 52 is substantially the same as the left front side frame 51.

  In the vehicle body front structure 11, the steering gear box 38 is moved rearward (in the direction of the arrow a2) by a collision applied to the front wall portion 126 of the inclined rear portion (side frame rear end) 122 facing the steering gear box 38 to the front surface 105 of the vehicle 12. ), The impact absorbing member 16 is arranged to deform and absorb the impact when pressed.

  4 (a) and 4 (b) are explanatory views of the impact absorbing member provided in the vehicle body front structure of the present invention, and FIG. 4 (a) is the impact absorbing attached to the inclined rear portion 122 of the front side frames 51 and 52. FIG. FIG. 4B is a front view of the member 16, and FIG. This will be described with reference to FIG.

  The shock absorbing member 16 is box-shaped, and includes an outer wall part 131, an inner wall part 132, an upper wall part 133, a lower wall part 134, and a receiving wall connected to these parts, which are joined to the side frame rear end (inclined rear part) 122. Part 135 and fixed integrally by welding (the x mark is a spot welded welded part (nugget)).

The receiving wall portion 135 is a flat surface, a predetermined range that comes into contact when the steering gear box 38 and / or the tie rod 41 retreats, and a predetermined range that receives even if the retreat position varies in the vertical direction. Arranged substantially vertically, the steering gear box 38 and / or the tie rod 41 are arranged at the center at a height H1 (see FIG. 5A) that comes into contact with the retracted position.
The receiving wall portion 135 is disposed at a distance E (see FIG. 5) from the steering gear box 38. The distance E is arbitrary depending on the configuration conditions of the shock absorbing member 16.

Next, the operation of the vehicle body front structure of the present invention will be described.
FIGS. 5A and 5B are diagrams illustrating the case of a front subframe that does not deviate from the mechanism for absorbing the load of the vehicle body front structure of the present invention. (A) shows before the load is applied to the front surface 105 of the vehicle 12, and (b) shows the time when the load is applied. This will be described with reference to FIG.

  The vehicle 12 (a) includes the shock absorbing member 16 of the vehicle body front structure 11, and a load starts to be applied to the front surface 105 of the vehicle 12.

  As shown in (b), when a load is applied to the front surface 105, the left front side frame 51, the right front side frame 52, and the subframe 15 start to absorb the load by deformation, and the subframe 15 is rearward. Move to (retreat). When the steering gear box 38 (including the tie rod 41) fixed to the gear box mounting portion 77, which is the rear portion of the subframe 15, moves backward (in the direction of the arrow a3) along with the movement (retreat), the receiving wall portion of the shock absorbing member 16 Since the shock absorbing member 16 is deformed by being in contact with and pressed against 135, the load is absorbed. Therefore, even if the steering gear box 38 is disposed on the front subframe 15, the load via the steering gear box 38 can be absorbed.

  Further, since the shock absorbing member 16 suppresses the backward movement of the steering gear box 38 (including the tie rod 41), as a result, the deformation of the dashboard lower 47 to the inside of the passenger compartment 22 (in the direction of the arrow a3) is suppressed. can do.

FIG. 6 is a comparative diagram comparing the load absorption mechanisms of the vehicle body front structure.
The horizontal axis represents time, and the vertical axis represents the load applied when the steering gear box 38 (including the tie rod 41) moves backward.
(A) is a comparative example without a shock absorbing member 16, and (b) is an embodiment of the present invention and corresponds to FIG.

  In the vehicle body front structure of the comparative example of (a), a load (not shown) starts to be applied to the front surface 105 at time T0, and the steering gear box 38 (including the tie rod 41) is attached to the side frame at time T1 after elapse of t1 seconds. The side frame rear end (inclined rear part) 122 and the dashboard lower 47 are deformed by the load F <b> 1 in contact with the rear end (inclined rear part) 122. Since the elapsed time t1 seconds is long, there is no resistance to the load of the steering gear box 38 (including the tie rod 41), and a large load F1 is generated at the moment when it hits the side frame rear end (inclined rear portion) 122. The deformation amount of the inward side frame rear end (inclined rear portion) 122 and the dashboard lower 47 is increased.

  In the embodiment of the present invention of (b), a load (not shown) starts to be applied to the front surface 105 at time T0, and the steering gear box 38 (including the tie rod 41) is impact-absorbing member at time T2 after t2 seconds. 16 abuts. The shock absorbing member 16 is deformed by the load F2 and absorbs the load. The elapsed time t2 is shorter than the elapsed time t1, and the impact absorbing member 16 continues to absorb the impact for the time t3 seconds. As a result, when the steering gear box 38 (including the tie rod 41) reaches the dashboard lower 47, the remaining load is reduced, and the side frame rear end (inclined rear portion) 122 and the dashboard lower 47 into the vehicle interior 22 are reduced. The amount of deformation can be reduced.

  The receiving wall portion 135 is disposed at a distance E (see FIG. 5) from the steering gear box 38, but by reducing the distance E, the load can be absorbed more.

  Although the shock absorbing member 16 is formed in a box shape, the load can be absorbed more by providing a rib or a buffer member in a box shape.

Next, another embodiment will be described.
FIGS. 7A and 7B are diagrams illustrating another embodiment. (A) is a side view and a view before a load is applied to the front surface 105 of the vehicle 12, and (b) shows a time when a load is applied.
The same components as those in the embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals and description thereof is omitted.

The vehicle body front structure 11B of another embodiment is a structure in which the subframe (front subframe) 15B is separated by an impact, and the shock absorbing member 16 is a subframe (front subframe) having a structure that does not deviate, It is arranged below.
The height H2 of the shock absorbing member 16 is lower than the height H1 of the shock absorbing member 16 by a distance h.

A load starts to be applied to the front surface 105 of the vehicle 12 in (a).
As shown in (b), when a load is applied to the front surface 105, the left front side frame 51, the right front side frame 52, and the subframe 15B are deformed and start to absorb the load, but the subframe 15B is When the fastening portion 73 is broken and the mount bolt 103 (see FIG. 2) of the fastening member 53 is pulled out and separated, the subframe 15B moves backward (retreats). When the steering gear box 38 (including the tie rod 41) fixed to the sub-frame 15B is retracted downward along with the downward movement (retreat), it contacts the receiving wall portion 135 of the shock absorbing member 16 lowered by the distance h. Since it is pushed, the shock absorbing member 16 is deformed to absorb the load. Therefore, even if the steering gear box 38 is disposed on the front subframe 15 that is separated, the load via the steering gear box 38 can be absorbed.

In addition, although the vehicle body front part structure of the present invention is adopted in the front body of the vehicle in the embodiment, it can be adopted other than the front body.
In the vehicle body front structure, the shock absorbing member is disposed on the front side frame, but the shock absorbing member may be disposed on a portion other than the front side frame.

  The vehicle body front structure of the present invention is suitable for a vehicle in which a steering gear box is mounted on a front subframe.

It is a top view explaining the outline | summary of the vehicle body front part structure of this invention. It is a perspective view of the vehicle body front part structure of this invention. It is a perspective view of the inclination rear part (side frame rear end) of a vehicle body front part structure. It is explanatory drawing of the impact-absorbing member with which the vehicle body front part structure of this invention is provided. It is a figure demonstrated in the case of the front sub-frame which does not deviate from the mechanism which absorbs the load of the vehicle body front part structure of this invention. It is a comparison figure which compares the load absorption mechanism of a vehicle body front part structure. It is a figure explaining another embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Vehicle body front part structure, 15 ... Front sub-frame (sub-frame), 16 ... Shock absorption member, 22 ... Car compartment, 23 ... Underbody, 25 ... Steering device, 38 ... Steering gear box, 51 ... Left front side frame 52 ... Right front side frame, 66 ... Rear portion of the front subframe (left rear end), 71 ... Right rear end (rear portion), 77 ... Rear vicinity of the front subframe (gearbox mounting portion), 122 ... Inclined rear portion (Side frame rear end), 126...

Claims (2)

An inclined rear portion of a front side frame that extends forward is connected to an underbody that forms the floor of the passenger compartment, and a rear portion of a front subframe having a cross beam shape is fastened to the inclined rear portion, and a long steering gear box of a steering device is disposed near the rear portion. In the front structure of the vehicle body where
An impact absorbing member that deforms and absorbs an impact when the steering gear box is displaced rearward due to a front collision of the vehicle is disposed on the front wall portion of the inclined rear portion facing the steering gear box. Body front structure characterized by   The vehicle body front structure according to claim 1, wherein the shock absorbing member is disposed below the front sub-frame in a structure in which the front subframe is separated due to an impact, compared to a structure in which the shock absorbing member is not separated.

Images