JP2009040337A - Front part vehicle body structure for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a front part vehicle body structure for an automobile capable of enhancing impact force absorption function at collision of the vehicle while enhancing support rigidity of a sub-frame. <P>SOLUTION: A front end part 3a of a floor side member 3 is superposed/bonded to an intermediate part in a vehicle width direction of a rear cross member part 12 of the sub-frame 4. On a neighborhood to front sides of bonding parts 13a, 14a of left and right rear corner parts 4d of the sub-frame 4 to the front side member 2, buckling inducing parts 13b, 14b buckled by impact load at collision of the vehicle are formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a front body structure of an automobile in which a sub-frame having a substantially rectangular shape is disposed below left and right front side members extending in the vehicle front-rear direction.

  In automobiles, a structure is adopted in which the rigidity of supporting the subframe on which the engine or the like is mounted to the body frame is enhanced and the impact force absorbing function at the time of a vehicle collision is enhanced.

For example, Patent Document 1 discloses that each corner portion of a rectangular frame-shaped subframe in plan view is coupled to a vehicle body frame, and left and right extensions formed extending from the subframe to the rear of the vehicle are used as the vehicle body frame. There has been proposed a structure in which bending-promoting portions are formed that are joined and further bent at the left and right side portions of the subframe by an impact force at the time of a vehicle collision.
JP 2005-271810 A

  By the way, in the conventional front vehicle body structure, six portions of each corner portion of the subframe and the left and right extension portions are coupled to the vehicle body frame. For this reason, although the support rigidity of the subframe can be increased, the left and right rear corners and the extension are separated from each other in the front-rear direction. There is a concern that sufficient impact force absorbing performance cannot be obtained.

  The present invention has been made in view of the above-described conventional situation, and an object of the present invention is to provide a front body structure of an automobile capable of improving impact force absorption performance at the time of a vehicle collision while increasing support rigidity of a subframe. .

  The present invention relates to left and right front side members extending in the vehicle front-rear direction, a floor side member extending in the vehicle front-rear direction disposed inside the left and right front side members, and the front side member. A substantially rectangular subframe having a front and rear cross member portions extending in the vehicle width direction and left and right side member portions extending in the vehicle front-rear direction, each corner portion of the subframe being In the front body structure of the automobile coupled to the left and right front side members, the front end of the floor side member is overlapped and coupled to the middle part in the vehicle width direction of the rear cross member, A buckling induction portion that buckles due to an impact load at the time of a vehicle collision is formed in the vicinity of the front side of the joint portion of the left and right rear corner portions with the front side member. It is.

  According to the front vehicle body structure according to the present invention, the connecting portion to the front side member of the left and right rear corner portions of the subframe, and the connecting portion to the floor side member in the vehicle width direction middle portion of the rear cross member portion, However, it is arranged in parallel in the vehicle width direction, and the support rigidity of the rear cross member portion of the subframe can be increased.

  As a result, stress concentrates on the buckling induction portion provided in the vicinity of the front side of the left and right rear coupling portions of the subframe, and the subframe is surely buckled and deformed. As a result, it is possible to prevent the subframe from being deformed and moving to the passenger compartment side at the time of a vehicle collision, and the impact force absorbing performance can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 7 are views for explaining a front body structure of an automobile according to an embodiment of the present invention. FIG. 1 is a plan view of the front body of the automobile, and FIG. 2 is a side view of the front body. 3 is a cross-sectional view of the front vehicle body (cross-sectional view taken along line III-III in FIG. 1), and FIGS. 4 and 5 are cross-sectional views of the front side member coupling portion of the subframe (cross-sectional view taken along line IV-IV in FIG. FIG. 6 and FIG. 7 are cross-sectional views (cross-sectional views taken along the line VI-VI and VII-VII in FIG. 1) of the floor side member connecting portion of the subframe.

  In the figure, reference numeral 1 denotes a front vehicle body of an automobile, which is disposed on the inner side in the vehicle width direction of the left and right front side members 2 and 2 extending in the longitudinal direction of the vehicle and the left and right front side members 2. And a pair of left and right floor side members 3 and 3 extending in the vehicle front-rear direction, and a sub-frame 4 disposed below the left and right front side members 2.

  Here, in FIG. 1, C is a vehicle body center line, and the front vehicle body 1 is symmetrical with respect to the vehicle body center line C.

  The front vehicle body 1 is arranged between left and right rocker members 5 and 5 extending in the vehicle front-rear direction and arranged on the outer side in the vehicle width direction of the left and right front side members 2, and the left and right rocker members 5. The floor panel 6 is disposed, and a dash panel 7 is coupled to the front edge of the floor panel 6 so as to extend upward, and the front vehicle body 1 defines an engine compartment a and a compartment b.

  The left and right front side members 2 include a front member portion 2a extending substantially horizontally, a kick portion 2b extending obliquely downward and rearward from the rear end of the front member portion 2a, and a vehicle width direction from the lower end of the kick portion 2b. A rear member portion 2c that extends rearward while expanding outward and is coupled to the inner wall 5a of the rocker member 5;

  The left and right front member portions 2a are formed to have a closed cross-section rectangular tube shape, and the kick portion 2b and the rear member portion 2c are formed to have a cross-sectional hat shape opening upward.

  Between the front ends of the left and right front member portions 2a, bumper-in hoses 9 extending in the vehicle width direction are disposed, and lower end portions of the suspension towers 10 and 10 are coupled to the left and right outer walls. Yes.

  The floor panel 6 is joined to the upper surfaces of the left and right kick parts 2b, the rear member part 2c and the left and right floor side members 3 by welding, and the left and right edge parts 6a and 6a are connected to the rocker member 5. The inner wall 5a is joined by welding.

  A tunnel portion 6b is formed in the center portion of the floor panel 6 in the vehicle width direction so as to protrude upward.

  The left and right floor side members 3 have a cross-sectional hat shape opening upward, and are arranged along the tunnel portion 6b on the left and right sides of the tunnel portion 6b of the floor panel 6.

  The left and right floor side members 3 are formed so that the distance in the vehicle width direction on the front side becomes narrower toward the rear side.

  The front end portions 3a, 3a of the left and right floor side members 3 are disposed so as to overlap the upper side of a rear cross member portion 12 (to be described later) of the subframe 4.

  The sub-frame 4 has a structure in which the outer peripheral edges are joined to each other by welding so as to form a hollow shape of the upper member 4a and the lower member 4b. The subframe 4 is mounted with an engine and a front wheel suspension device (not shown).

  The sub-frame 4 has a generally rectangular shape when viewed from above the front cross member portion 11 and the rear cross member portion 12 extending in the vehicle width direction, and the left side member portion 13 and the right side member portion 14 extending in the vehicle front-rear direction. It has a structure joined by welding to form a letter shape.

  The sub-frame 4 has left and right front corner portions 4c and 4c and left and right rear corner portions 4d and 4d coupled to the left and right front side members 2, and has the following structure in detail. ing.

  Left and right front coupling portions 16 and 16 extending outward in the vehicle width direction are formed at the front end portions of the left and right side member portions 13 and 14, respectively. The left and right front coupling portions 16 are disposed so as to overlap vertically below the left and right front member portions 2a.

  The left and right front member portions 2a are joined to the front U-shaped brackets 17 and 17 extending downward by welding. The left and right front coupling brackets 17 are joined to the lower surfaces of the left and right front coupling brackets 17 by welding. The front coupling portion 16 is coupled by front coupling bolts 18 and 18 attached from below.

  The left and right side member parts 13 and 14 extend rearward along the inner surface of the left and right front member part 2a, and then bend the left and right rear joint parts 13a and 14a extending outwardly in the vehicle width direction. Have. The left and right rear coupling portions 13a and 14a are arranged so as to overlap vertically below the kick portion 2b.

  Cylindrical collars 25 and 25 are disposed in the rear coupling portions 13a and 14a of the left and right side member portions 13 and 14 with their axes directed upward and downward.

  The left and right kick parts 2b are joined to the lower U-shaped rear joint brackets 20 and 20 extending downward by welding, and the left and right rear joint brackets 20 are connected to the lower surface of the left and right rear joint brackets 20 by welding. After the parts 13a and 14a are attached from below, they are connected by connecting bolts 21 and 21.

  A front end portion 3a of the left and right floor side members 3 is arranged above the middle portion in the vehicle width direction of the rear cross member portion 12 so as to overlap in the vertical direction. Cylindrical collars 26 and 26 are arranged in the rear cross member portion 12 corresponding to the front end portions 3a of the left and right floor side members 3 with their axes directed vertically.

  Upwardly U-shaped coupling brackets 23, 23 extending downward are joined to the front end portions 3a of the left and right floor side members 3 by welding, and the rear surfaces of the left and right coupling brackets 23 are connected to the rear surface. The cross member 12 is connected by connecting bolts 24, 24 attached from below.

  A connecting bolt 24 that connects the rear cross member 12 and the left and right floor side members 3 is connected to the connecting parts 13a and 14a between the vehicle body center line C and the left and right rear connecting parts 13a and 14a. It is located closer to the side, and is located slightly behind the straight line connecting the left and right rear coupling bolts 21, 21. In other words, the left and right coupling bolts 24 of the rear cross member 12 and the left and right rear coupling bolts 21 are arranged in parallel so as to be positioned substantially on the same line in the vehicle width direction.

  Buckling induction portions 13b and 14b that buckle due to an impact load at the time of a vehicle collision are formed in the vicinity of the front side of the rear coupling bolts 21 and 21 of the left and right side member portions 13 and 14 of the subframe 4.

  The left and right buckling induction portions 13b and 14b are formed by forming wedge-shaped recesses extending in the vehicle width direction on the lower and upper surfaces of the left and right side member portions 13 and 14, respectively.

  The left and right buckling induction portions 13b and 14b are formed in two strips at a predetermined interval in the front and rear direction. Thus, when a collision load is applied at the time of a vehicle collision, the left and right side member portions 13 and 14 are configured to bend downward in a square shape starting from the buckling induction portions 13b and 14b.

  According to this embodiment, the left and right rear corner portions 4 d of the subframe 4 are joined to the front side members 2, the rear coupling bolts 21 and 21, and the rear cross member portion 12 are joined to the front ends of the left and right floor side members 3. Since the coupling bolts 24, 24 for coupling the portion 3a are arranged so as to be aligned on the same line in the vehicle width direction, the support rigidity of the rear cross member portion 12 of the subframe 4 can be increased.

  As a result, stress concentrates on the buckling induction portions 13b and 14b formed near the front side of the left and right rear coupling portions 13a and 14a of the subframe 4, and the left and right side member portions 13 and 14 are surely buckled and deformed. It will be. As a result, it is possible to prevent the subframe 4 from being twisted and deformed to move toward the passenger compartment b at the time of a vehicle collision, and to improve the impact force absorption performance.

  That is, for example, when an impact load is applied to the right side member portion 14 due to an offset collision, the load is transmitted to the left side member portion 13 via the rear cross member portion 12. As a result, the collision energy is distributed to the left and right side member portions 13 and 14, and the energy can be absorbed efficiently.

1 is a plan view of a front vehicle body of an automobile according to an embodiment of the present invention. It is a side view of the front vehicle body. FIG. 3 is a sectional view of the front vehicle body (a sectional view taken along line III-III in FIG. 1). FIG. 4 is a cross-sectional view (a cross-sectional view taken along line IV-IV in FIG. 1) of a front side member coupling portion of a sub-frame of the front vehicle body. FIG. 5 is a cross-sectional view (cross-sectional view taken along the line VV in FIG. 1) of the front side member coupling portion of the subframe. It is sectional drawing (the VI-VI line sectional drawing of FIG. 1) of the floor side member coupling | bond part of the said sub-frame. It is sectional drawing (the VII-VII sectional view taken on the line of FIG. 1) of the floor side member coupling | bond part of the said sub-frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front vehicle body 2 Front side member 3 Floor side member 3a Front end part 4 Sub frame 4c, 4d Corner part 11 Front cross member part 12 Rear cross member part 13 Left side member part 13a Rear joint part 13b Buckling induction part 14 Right side Member part 14a Rear joint part 14b Buckling induction part

Claims (1)

The left and right front side members extending in the vehicle front-rear direction, the floor side member extending in the vehicle front-rear direction disposed inside the left and right front side members in the vehicle width direction, and disposed below the front side member A substantially rectangular subframe having front and rear cross member portions extending in the vehicle width direction and left and right side member portions extending in the vehicle front-rear direction, and each corner portion of the subframe is connected to the left and right corners. In the front car body structure of the car connected to the front side member,
In the vehicle width direction midway part of the rear cross member part, the front end part of the floor side member is overlapped and joined,
A front part of an automobile characterized in that a buckling induction part that buckles due to an impact load at the time of a vehicle collision is formed in the vicinity of the front side of the joint part of the left and right rear corner parts with the front side member of the subframe. Body structure.

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