JP6159974B2 - Front cross member - Google Patents

Description

  The present invention relates to a front cross member that supports a lower arm at both ends in a vehicle width direction.

  In the front structure of the vehicle body, a front cross member is bridged between side members provided on both sides in the vehicle width direction, and the wheels are connected to both ends of the front cross member in the vehicle width direction via the lower arm of the suspension device. The thing which was made to support is provided.

  When the vehicle employing the vehicle body front structure described above is traveling, various loads are applied to the wheels from the front side of the vehicle or the rear side of the vehicle. And the load which acted on the wheel is input to the front cross member from the lower arm that supports it.

  In view of this, in the vehicle body front structure described above, it is necessary to cope with the load acting on the wheels when the vehicle travels, so that the strength and rigidity of the lower arm support portion are improved in the front cross member. Such conventional front cross members are disclosed in, for example, Patent Documents 1 and 2.

JP 2004-203240 A JP 2008-1307 A

  In the above-described conventional front cross member, the front cross member is composed of an upper plate and a lower plate, and further, a lower arm is supported between the plates, and the lower arm support portions of the upper plate and the lower plate are reinforced. It is connected by a board. However, in such a conventional front cross member, although the strength and rigidity of the lower arm support portion can be improved, there is a risk of increasing the weight by the provision of the reinforcing plate.

  In recent years, there has been a tendency to reduce the thickness of the body by reducing the thickness of the body for reasons such as improving fuel efficiency, and the front cross member constituting the body is no exception.

  However, if the front cross member is to be thinned for the purpose of reducing the weight of the vehicle body, its strength and rigidity will be reduced. In particular, since both ends of the lower plate in the vehicle width direction are portions that support the lower arm, it requires more strength and rigidity than other portions, and there is a limit to reducing the thickness of the lower arm support portion. is there.

  Therefore, with the conventional front cross member as described above, it is difficult to achieve both weight reduction and maintenance of the support strength and support rigidity of the lower arm. Conceivable.

  Accordingly, an object of the present invention is to provide a front cross member that can reduce the weight while improving or maintaining the support strength and support rigidity of the lower arm.

The front cross member according to the first invention for solving the above-mentioned problems is
The upper plate disposed at the upper portion and the lower plate disposed at the lower portion are disposed so as to face each other in the vertical direction, and the base end of the lower arm that supports the wheel is disposed between the upper plate and the lower plate. In the front cross member that is attached to both ends in the vehicle width direction,
The lower plate is
A center plate disposed in the center in the vehicle width direction;
Side plates disposed on both sides in the vehicle width direction and formed with a plate thickness greater than the plate thickness of the center plate;
A first reinforcing plate that is erected on both ends of the center plate in the vehicle width direction and whose upper end is joined to the upper plate;
A second reinforcing plate extending from the front end in the vehicle longitudinal direction of the first reinforcing plate toward the outside in the vehicle width direction, the lower end of which is joined to the side plate;
The lower arm is supported between the upper plate and the side plate.

A front cross member according to a second invention for solving the above-mentioned problems is as follows.
Comprising a stabilizer attached to the upper surface of the upper plate via a bracket;
The upper end of the first reinforcing plate , the upper plate, and the bracket are overlapped and joined in the vertical direction.

A front cross member according to a third invention for solving the above-mentioned problems is
An arm member supported by a vehicle body skeleton member disposed above the upper plate;
The base end of the arm member is supported across the upper plate and the side plate.

  Therefore, according to the front cross member of the present invention, the lower plate is divided into the center plate and the side plate, and the reinforcing plate is formed on the center plate, while the lower arm is supported between the upper plate and the side plate. Thus, only the plate thickness of the side plate can be formed larger than the plate thickness of the center plate. As a result, the weight of the entire front cross member can be reduced while improving or maintaining the support strength and support rigidity of the lower arm.

1 is a front perspective view of a front body structure that employs a front cross member according to an embodiment of the present invention. It is the figure which showed the structure of the lower plate. It is the disassembled perspective view which showed the structure of the front cross member which concerns on one Example of this invention. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3.

  Hereinafter, a front cross member according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a hollow front cross member 11 is provided at the front of the vehicle body so as to extend in the vehicle width direction. The front cross member 11 is configured such that an upper plate 31 disposed at an upper portion and a lower plate 32 disposed at a lower portion face each other in the vertical direction.

  The upper plate 31 has a box shape opened downward, while the lower plate 32 is formed in a flat plate shape. Therefore, the hollow front cross member 11 is obtained by joining the front lower edge and rear lower edge of the upper plate 31 and the front edge and rear edge of the lower plate 32 by welding, bolts, or the like. be able to.

  Here, arm members 12 are provided at both ends in the vehicle width direction of the front cross member 11 so as to protrude outward in the vehicle width direction and upward. The base end of the arm member 12 is supported across the upper plate 31 and the lower plate 32. On the other hand, the upper end of the arm member 12 is supported by the lower surface of a side member (vehicle body frame member) 13 provided on both sides in the vehicle width direction.

  Note that attachment portions 11 a are formed on the rear side of both ends in the vehicle width direction of the front cross member 11. The front cross member 11 is supported by the side member 31 at four points on the upper end of the attachment portion 11 a and the arm member 12.

  Further, at both ends in the vehicle width direction of the upper plate 31 and the lower plate 32, the base end of the lower arm 14 constituting the suspension device is supported via a rubber bush 15 so as to be swingable in the vertical direction. A knuckle (not shown) of a steered wheel (front wheel) 17 is supported at the tip of the lower arm 14 via a joint portion 16. Thus, by supporting the suspension device on the front cross member 11 attached to the side member 13, the support rigidity of the suspension device is improved.

  Further, a stabilizer 18 is supported on the upper surfaces of the upper plate 31 and the lower arm 14. The stabilizer 18 is arranged to extend in the vehicle width direction along the upper surfaces of the upper plate 31 and the lower arm 14.

  In the lower arm 14, both ends of the stabilizer 18 in the vehicle width direction are supported via rubber bushes 19. On the other hand, in the upper plate 31, the intermediate portion in the vehicle width direction of the stabilizer 18 is supported via the bracket 20. Thus, by supporting the stabilizer 18 over the front cross member 11 and the lower arm 14, the roll rigidity of the vehicle is improved.

  Next, the configuration of the front cross member 11 will be described in detail with reference to FIGS. 3 and 4, the left side portion of the front cross member 11 in the vehicle width direction is illustrated.

  As shown in FIGS. 2 to 4, the lower plate 32 includes a center plate 41 disposed at the center in the vehicle width direction and side plates 42 disposed at both sides in the vehicle width direction. The side plates 42 are joined to both ends of the center plate 41 in the vehicle width direction, and the plate thickness is formed to be thicker than the plate thickness of the center plate 41.

  A first reinforcing plate (reinforcing plate) 51 is erected on both ends of the center plate 41 in the vehicle width direction, and a second reinforcing plate (reinforcing plate) 52 is connected to the first reinforcing plate 51. Yes.

  And the upper end of the 1st reinforcement board 51 is joined to the lower surface of the upper plate 31, and this joining position has opposed the attachment position of the bracket 20 in the upper plate 31 in the up-down direction. That is, the mounting position of the bracket 20 that supports the stabilizer 18 to the upper plate 31 and the joining position of the upper end of the first reinforcing plate 51 to the upper plate 31 are the same at the upper and lower positions sandwiching the upper plate 31. It is comprised so that it may become. Specifically, the bracket 20 is fastened by a bolt at a joining position where the upper end of the first reinforcing plate 51 in the upper plate 31 is joined. On the other hand, the lower end of the first reinforcing plate 51 is connected to the upper surface of the side plate 42.

  The second reinforcing plate 52 extends from the front end of the first reinforcing plate 51 toward the outside in the vehicle width direction, and the lower end thereof is joined to the upper surface of the side plate 42.

  Thus, by forming the first reinforcing plate 51 and the second reinforcing plate 52 on the center plate 41, not only the support rigidity of the stabilizer 18 is improved, but also the rigidity of the front cross member 11 is improved. . In the above-described embodiment, the first reinforcing plate 51 and the second reinforcing plate 52 are integrally formed. However, they may be formed separately.

  Further, between the upper plate 31 and the side plate 42, the arm member 12 is supported by penetrating in the vertical direction, and the lower arm 14 is supported by being sandwiched in the vertical direction.

  In other words, in the lower plate 32, the load applied to the steering wheel 17 when the vehicle is traveling is more input to both sides in the vehicle width direction that support the lower arm 14. The center plate 41 and the side plates 42 located on both sides in the vehicle width direction are divided into two parts so that the thickness of the center plate 41 is reduced while the thickness of the side plate 42 is increased. Thus, the weight of the lower plate 32 (front cross member 11) is reduced while improving the support rigidity of the lower arm 14.

  Then, the first reinforcing plate 51 and the second reinforcing plate 52 are integrally formed on the center plate 41, and the first reinforcing plate 51 is superposed on the mounting position of the stabilizer 18 which is a highly rigid body, and the second reinforcing plate The rigidity of the center plate 41 can be improved by joining the plate 52 to the side plate 42 that is thickened to increase the rigidity. Thereby, when making the plate | board thickness of the center plate 41 thin, the plate | board thickness can be made as thin as possible.

  Further, the side plate 42 is reinforced by the second reinforcing plate 52 that is continuous with the first reinforcing plate 51 as described above, and is supported by the arm member 12 that is joined to the side member 13 that is a highly rigid body. The rigidity of the side plate 42 can be improved. Accordingly, when the plate thickness of the side plate 42 is increased, the thickness of the side plate 42 can be prevented from being increased more than necessary, and the support rigidity of the lower arm 14 in the side plate 42 can be improved.

  Therefore, according to the front cross member 11 according to the present invention, the lower plate 32 is divided into the center plate 41 and the side plate 42, and the first reinforcing plate 51 and the second reinforcing plate 52 are divided into the center plate 41. On the other hand, the lower arm 14 is supported by the side plate 42, and the thickness of the side plate 42 is made thicker than the thickness of the center plate 41, thereby improving or maintaining the support strength and support rigidity of the lower arm 14. However, the weight can be reduced.

  Moreover, the rigidity of the center plate 41 with respect to the upper plate 31 can be improved by superposing the upper end of the first reinforcing plate 52 to the upper plate 31 and the bracket 20 for attaching the stabilizer 18. As a result, the thickness of the center plate 41 can be reduced as much as the rigidity of the center plate 41 is improved, and thus the weight can be further reduced. Furthermore, it is possible to sufficiently cope with the load input from the stabilizer 18.

  Further, by supporting the base end of the arm member 12 supported by the side member 13 on the side plate 42, the rigidity of the side plate 42 can be improved. Thereby, the support strength and support rigidity of the lower arm 14 can be improved without increasing the thickness of the side plate 42 more than necessary. At the same time, the support rigidity of the arm member 12 and the support rigidity to the side member 13 in the front cross member 11 can also be improved.

  The present invention can be applied to a vehicle body structure for the purpose of reducing the weight of the vehicle body by realizing a reduction in the thickness of the front cross member.

11 Front cross member 12 Arm member 13 Side member 14 Lower arm 17 Steering wheel 18 Stabilizer 20 Bracket 31 Upper plate 32 Lower plate 41 Center plate 42 Side plate

Claims (3)

The upper plate disposed at the upper portion and the lower plate disposed at the lower portion are disposed so as to face each other in the vertical direction, and the base end of the lower arm that supports the wheel is disposed between the upper plate and the lower plate. In the front cross member that is attached to both ends in the vehicle width direction,
The lower plate is
A center plate disposed in the center in the vehicle width direction;
Side plates disposed on both sides in the vehicle width direction and formed with a plate thickness greater than the plate thickness of the center plate;
A first reinforcing plate that is erected on both ends of the center plate in the vehicle width direction and whose upper end is joined to the upper plate;
A second reinforcing plate extending from the front end in the vehicle longitudinal direction of the first reinforcing plate toward the outside in the vehicle width direction, the lower end of which is joined to the side plate;
A front cross member, wherein the lower arm is supported between the upper plate and the side plate. The front cross member according to claim 1,
Comprising a stabilizer attached to the upper surface of the upper plate via a bracket;
A front cross member, wherein an upper end of the first reinforcing plate, the upper plate, and the bracket are overlapped and joined in the vertical direction. The front cross member according to claim 1 or 2,
An arm member supported by a vehicle body skeleton member disposed above the upper plate;
The front cross member characterized by supporting the base end of the said arm member over the said upper plate and the said side plate.

Images