JP4922002B2 - Subframe structure of vehicle - Google Patents

Description

The present invention connects both ends of a front horizontal member extending in the vehicle width direction to the front ends of a pair of left and right vertical members extending in the longitudinal direction of the vehicle body, and in the vehicle width direction on the rear ends of the pair of left and right vertical members. The present invention relates to a vehicle sub-frame structure in which a frame-like sub frame in which both end portions of an extending rear lateral member are connected is supported below a pair of left and right front side frames extending in the longitudinal direction of a vehicle body.

  A sub-frame structure of such a vehicle is known from Patent Document 1 below.

In this subframe structure of the vehicle, extensions (crash pipes 22) project from the left and right ends of the front horizontal member (front cross member 15) of the subframe (front subframe 17) to the front of the vehicle body. The front ends are connected by a load receiving member (reinforcement 23). Therefore, when a relatively small collision load is input to the load receiving member due to the frontal collision of the vehicle, the collision load is absorbed by bending of the load receiving member or buckling of the extension, and is also received by the frontal collision of the vehicle. When a relatively large collision load is input to the member, the collision load can be absorbed by buckling of the left and right vertical members (side frames 14) of the subframe.
JP 2005-271809 A

  By the way, what is described in the above-mentioned patent document 1 is that the front horizontal member of the subframe hardly contributes to shock absorption regardless of whether the collision load is small or large. Not only is it difficult to exhibit the absorption performance, but there is a possibility that the upper limit value of the shock absorption capacity is limited.

  The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to cause the subframe to exhibit appropriate shock absorption performance according to the magnitude of the collision load and to increase the upper limit value of the shock absorption capacity by the subframe. .

In order to achieve the above object, according to the first aspect of the present invention, both ends of the front horizontal member extending in the vehicle width direction are connected to the front ends of the pair of left and right vertical members extending in the vehicle longitudinal direction. A vehicle in which a frame-like subframe in which both end portions of a rear lateral member extending in the vehicle width direction are connected to rear end portions of the pair of left and right vertical members is supported below a pair of left and right front side frames extending in the vehicle body longitudinal direction. in the sub-frame structure, said front transverse member the ends extension from the vehicle width direction inner side than the portion of the projecting from the front of the vehicle body, when the collision load inputted from the front side of the vehicle body is small the extensions buckled impact When the collision load is medium, the front lateral member of the subframe bends to absorb impact, and when the collision load is large, the subframe Wherein both longitudinal members vehicle front structure of a vehicle, characterized in that to absorb the shock buckles are proposed.

  According to the second aspect of the present invention, in addition to the structure of the first aspect, the front engine mount that supports the front portion of the engine on the subframe is provided with the pair of left and right of the front lateral member. A vehicle subframe structure characterized by being provided between extensions is proposed.

  According to the configuration of the first aspect, when the collision load input from the front side of the vehicle body is small, the extension projecting forward from the front lateral member of the subframe is buckled to absorb the impact. When the collision load input from the front side of the vehicle body is medium, the front horizontal member of the subframe is bent by the collision load transmitted through the extension to absorb the impact. Further, when the collision load input from the front side of the vehicle body is large, the left and right vertical members of the subframe are buckled by the collision load input from the front horizontal member of the subframe to absorb the impact. As a result, it is possible to exhibit shock absorbing performance in three stages according to the magnitude of the collision load, and it is possible to increase the upper limit value of the shock absorbing performance by sharing the shock absorbing performance with the front side member as well. .

  According to the second aspect of the present invention, the engine mount for supporting the front portion of the engine on the subframe is provided between the left and right extensions of the front horizontal member of the subframe. When a collision load is input, the two portions sandwiched between both ends of the front lateral member and the front engine mount can be bent backward to absorb a large impact.

  According to the third aspect of the present invention, since the lower portion of the radiator is supported by the extension, a special bracket for supporting the radiator is not required, and the number of parts can be reduced and the weight can be reduced.

  According to the fourth aspect of the present invention, since the extension is fixed to the front lateral member with the bolt, the replacement when the extension is damaged is facilitated, and the repair cost can be reduced.

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

  1 to 5 show an embodiment of the present invention. FIG. 1 is a plan view of a subframe at the front of the vehicle body, FIG. 2 is a perspective view of the subframe, and FIG. 3 is a line 3-3 in FIG. FIG. 4 is an enlarged cross-sectional view, FIG. 4 is an explanatory diagram of the action at the time of collision, and FIG.

  As shown in FIGS. 1 to 3, a pair of left and right front side frames 11, 11 extending in the longitudinal direction of the vehicle body are disposed on the left and right sides of the front portion of the vehicle body. A rectangular frame-shaped subframe 12 that supports an engine, a transmission, a suspension, and the like is supported on the lower surface. The subframe 12 includes a pair of left and right vertical members 13 and 13 extending in the longitudinal direction of the vehicle body, a front horizontal member 14 connecting the front ends of the vertical members 13 and 13 in the vehicle width direction, and the vertical members 13 and 13. A rear horizontal member 15 that connects the rear ends in the vehicle width direction is provided, and is configured in a square frame shape. The left and right front end portions are rubber bush joints 16, 16 on the front lower surfaces of the front side frames 11, 11. The left and right rear ends are elastically supported on the lower surfaces of both front side frames 11 and 11 via rubber bush joints 17 and 17.

  A pair of left and right extensions 18, 18 spaced in the vehicle width direction are fixed to the front horizontal member 14 of the subframe 12 with bolts 19 so as to protrude forward of the vehicle body, and between the front ends of the extensions 18, 18 Is coupled to the rear surface of the load receiving member 20 disposed in the vehicle width direction. Since the extensions 18 and 18 are fixed to the front lateral member 14 with bolts 19..., The replacement when the extensions 18 and 18 are damaged is facilitated, and the repair cost can be reduced.

  An integrated engine E and transmission T are mounted on the subframe 12, and a front engine mount 21 that supports the front portion of the engine E is a central portion in the vehicle width direction of the front lateral member 14 of the subframe 12. Is provided. Accordingly, the left extension 18 is disposed between the left rubber bush joint 16 and the front engine mount 21, and the right extension 18 is disposed between the right rubber bush joint 16 and the front engine mount 21. It will be.

  Rubber bush joints 22 and 22 are respectively provided at the front and rear center portions of the extensions 18 and 18, and the lower ends of the radiators 23 of the rubber bush joints 22 and 22 are supported. Thus, by supporting the radiator 23 using the extensions 18 and 18, the conventional frame-shaped radiator support becomes unnecessary, and the weight can be reduced and the number of parts can be reduced.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  As shown in FIG. 4A, when a small collision load is input to the load receiving member 20 due to a frontal collision at a low vehicle speed and low energy, a gap between the load receiving member 20 and the front horizontal member 14 of the subframe 12 is obtained. The pair of left and right extensions 18, 18 disposed in the longitudinal direction of the vehicle body buckle to absorb the collision load. At this time, the front horizontal member 14 and the vertical members 13 and 13 of the sub-frame 12 having higher rigidity than the extensions 18 and 18 are not deformed.

  As shown in FIG. 4B, when a moderate collision load is input to the load receiving member 20 due to a frontal collision at medium vehicle speed and medium energy, the pair of left and right extensions 18 and 18 are completely buckled. The front lateral member 14 of the subframe 12 pushed by the extensions 18 and 18 is bent to absorb the collision load. At this time, the vertical members 13 and 13 having higher rigidity than the front horizontal member 14 of the subframe 12 are not deformed. In addition, since the center portion in the vehicle width direction of the front side member 14 is restrained by the front engine mount 21 so as not to be retracted, the front side member 14 is disposed between the left rubber bush joint 16 and the front engine mount 21. Bending backward at two locations between the right rubber bush joint 16 and the front engine mount 21, a greater impact absorbing effect can be exhibited.

  As shown in FIG. 4C, when a large collision load is input to the load receiving member 20 due to a frontal collision at a high vehicle speed and high energy, the pair of left and right extensions 18, 18 are completely buckled, and both the extensions 18, The front horizontal member 14 of the subframe 12 pushed by 18 is completely bent, and the left and right vertical members 13 and 13 of the subframe 12 are buckled to absorb the collision load.

  As described above, as the collision load input to the load receiving member 20 increases due to the frontal collision, only the extensions 18 and 18 or both the extensions 18 and 18 and the front horizontal member 14 of the subframe 12 are present. Alternatively, the extension 18, 18, the front horizontal member 14 of the subframe 12 and the vertical members 13, 13 are all deformed to absorb the collision load, so that a wide area from the collision of the small vehicle to the collision of the large vehicle is obtained. Can exhibit necessary and sufficient shock absorbing performance.

  Moreover, the total shock absorbing function of the subframe 12 can be enhanced by causing the front lateral member 14 of the subframe 12 that has not conventionally contributed to the absorption of the collision load to exhibit the shock absorbing function.

  FIG. 5 shows a change in the load with respect to the displacement of the load receiving member 20 due to the input of the collision load. In the region a immediately after the collision, the low-rigid extensions 18 and 18 are crushed, so that the generated load can be kept small. In the subsequent region b, a slightly large load is generated by bending the front lateral member 14 of the subframe 12. In the subsequent region c, the maximum load is generated by the buckling of the vertical members 13 and 13.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, in the embodiment, two extensions 18 and 18 are provided, but the number is arbitrary.

Plan view of the subframe at the front of the car body Similarly perspective view of subframe 3-3 enlarged sectional view of FIG. Action diagram at the time of collision Graph showing load absorption characteristics at impact

11 Front side frame 12 Subframe 13 Vertical member 14 Front side member 15 Rear side member 18 Extension 21 Front engine mount E Engine

Claims (4)

Both ends of a front horizontal member (14) extending in the vehicle width direction are connected to front ends of a pair of left and right vertical members (13) extending in the longitudinal direction of the vehicle body, and rear ends of the pair of left and right vertical members (13). A sub-frame of a vehicle in which a frame-like subframe (12) in which both ends of a rear lateral member (15) extending in the vehicle width direction are connected to each other is supported below a pair of left and right front side frames (11) extending in the vehicle body longitudinal direction. In the frame structure,
Said end portions of the extension (18) from the inward projecting from the front of the vehicle body than the extension when the collision load inputted from the vehicle front side is smaller (18) of the seat of the front transverse member (14) When the impact load is medium, the front lateral member (14) of the subframe (12) bends to absorb the impact, and when the impact load is large, the subframe is bent. The vehicle body front structure according to claim 12, wherein the vertical members (13) of (12) are buckled to absorb impact.   A front engine mount (21) for supporting the front part of the engine (E) is provided between the pair of left and right extensions (18) of the front side member (14) on the subframe (12). The vehicle sub-frame structure according to claim 1, wherein:   The vehicle sub-frame structure according to claim 1, wherein a lower part of a radiator (23) is supported by the extension (18).   The sub-frame structure for a vehicle according to claim 1, wherein the extension (18) is fixed to the front lateral member (14) with a bolt (19).

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