JP4875508B2 - Vehicle front structure - Google Patents

Description

  The present invention relates to a vehicle body front structure for a vehicle in which a front end of a pair of left and right front side frames extending in the longitudinal direction of the vehicle body and a front end of a pair of left and right upper members extending from the front end of a front pillar to the front lower side of the vehicle body.

A front part of a vehicle body in which a front end side surface of a pair of left and right front side frames and a front end side surface of a pair of left and right upper members extending from the front end of the pair of left and right front pillars to the front lower side of the vehicle are connected via a connecting member extending in the vehicle width direction. The structure is known from Patent Document 1 below.
JP 2005-112173 A

  By the way, although what was described in the said patent document 1 demonstrates the effect of transmitting the load of a frontal collision from an upper member to a front pillar by forming an upper member substantially linearly, and raising an impact absorption effect, Since the front side frame and the upper member are connected at the same height via the connecting member, the height of the front end of the front side frame of the host vehicle and the front end of the upper member at the time of the collision is the same as that of the bumper beam or side sill of the other vehicle. If they do not match the height, they may pass each other and may not provide a sufficient impact absorbing effect. In addition, since the front side frame and the upper member are connected via a connecting member, the transmission of the collision load between the front side frame and the upper member becomes insufficient, and a sufficient impact absorbing effect may not be obtained. There was sex.

  The present invention has been made in view of the above circumstances, and prevents collision between frames at the time of a collision with another vehicle having a different vehicle height, thereby improving the mutual shock absorption effect and reducing the collision load input to the host vehicle. The object is to increase the impact absorption effect by dispersing in many members.

To achieve the above object, according to the first aspect of the present invention, the front ends of a pair of left and right front side frames extending in the longitudinal direction of the vehicle body, and the pair of left and right upper members extending downward from the front end of the front pillar to the front of the vehicle body. The front end portion of the bent portion that extends in the vehicle width direction is formed by bending the front portion of the upper member inward in the vehicle width direction with a hydroform to form a bent portion. A bumper beam extension that is fixed so as to straddle the connecting portion of the front side frame and the upper member is projected to the front of the vehicle body , with the upper surface overlapped with the lower surface of the front end portion of the front side frame in the vertical direction. and, front body structure of a vehicle, characterized in that the bumper beam supported at the front end of the bumper beam extension There is proposed.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the front portion of the subframe is supported on the lower surface of the bent portion of the upper member. A structure is proposed .

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, a vehicle body front structure is proposed in which a radiator support is supported by the bumper beam extension. Is done.

According to the configuration of the first aspect, the front portions of the pair of left and right upper members extending downward from the front end of the front pillar from the front end of the front pillar are bent inward in the vehicle width direction by hydroforming to form a bent portion, and the vehicle width direction since bound superposed in the vertical direction upper surface of the front end portion of the bent portion extending in the front lower surface of the pair of left and right front side frames extending in the longitudinal direction of the vehicle body, a front side frame coupled one on top during frontal collision of the vehicle And it is possible to receive the collision load in a wide area in the vertical direction from the upper end to the lower end of the upper member connecting part, and prevent the passing of frames between each other at the time of collision with other vehicles with different vehicle heights. not only can increase, wider the than the vehicle width direction of the width of the front side frame in the vehicle width direction of the bent portion of the upper member , It can be in the vehicle width direction a wide region by receiving a collision load to secure a shock absorbing effect when another vehicle and so as to offset collision. Further, since the bent portion of the upper member is formed by hydroforming, a bent portion having a complicated shape can be formed at low cost. In addition, since the front end of the front side frame and the front end of the upper member are directly connected without a connecting member, the impact load can be distributed to both the front side frame and the upper member to enhance the impact absorbing effect. Furthermore, since the bent portion of the upper member is bent and deformed rearward of the vehicle body in response to the collision load, the impact absorption effect can be enhanced. Furthermore, the bumper beam extension is projected from the joint of the front side frame and upper member toward the front of the vehicle body, and the bumper beam is supported at the front end of the bumper beam extension. It can be dispersed and effectively absorbed in both the side frame and the upper member.

According to the second aspect of the present invention, since the front portion of the subframe is supported on the lower surface of the front end portion of the upper member, the bracket extending downward from the front end of the front side frame to support the subframe can be eliminated. Therefore, the number of parts can be reduced and the structure can be simplified .

According to the third aspect of the present invention, since the radiator support is supported by the bumper beam extension, even if the bumper beam extension is retracted during a light collision, the radiator support that supports the radiator is retracted together with the bumper beam extension. Damage can be minimized.

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

  1 to 6 show an embodiment of the present invention. FIG. 1 is a perspective view of a front part of a vehicle body of a vehicle, FIG. 2 is a view taken in the direction of the arrow in FIG. 1, and FIG. 4 is a view taken along the line 2-2 in FIG. 2, FIG. 5 is a perspective view of a portion where the bumper beam extension is coupled to the front side frame and the upper member, and FIG. is there.

  As shown in FIGS. 1 to 4, 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 side portions of the vehicle body front portion. At the front part of the pair of left and right upper members 12, 12 extending from the front end of a pair of left and right front pillars (not shown) to the front lower side of the vehicle body, substantially horizontal horizontal parts 12a, 12a are formed, and these horizontal parts 12a, 12a Bending portions 12b and 12b that are bent inward in the vehicle width direction are provided continuously. Such upper members 12 and 12 can be formed at low cost by hydroforming. The upper surfaces of the inner ends in the vehicle width direction of the bent portions 12b and 12b of the upper members 12 and 12 are overlapped with the lower surfaces of the front ends of the front side frames 11 and 11, and are integrally welded W (see FIG. 5).

  A rectangular frame-shaped sub-frame 13 disposed below the front side frames 11 and 11 includes a pair of left and right vertical members 14 and 14 extending in the longitudinal direction of the vehicle body, and a pair of left and right vertical members 14 and 14 extending in the lateral direction of the vehicle body. A front horizontal member 15 that connects the front ends and a rear horizontal member 16 that extends in the left-right direction of the vehicle body and connects between the rear ends of both vertical members 14, 14, an engine (not shown), Transmission, suspension, etc. are assembled.

  The left and right front end portions of the sub frame 13 are elastically supported on the lower surfaces of the bent portions 12b and 12b of the upper members 12 and 12 via rubber bush joints 17 and 17, and the left and right rear end portions thereof are both front side frames 11. , 11 is elastically supported on the lower surface of the downward bent portion via rubber bush joints 18, 18.

  As is apparent from FIG. 5, a pair of left and right bumper beam extensions 19 are formed on the front surface of the portion where the front ends of the front side frames 11 and 11 and the front ends of the upper members 12 and 12 are overlapped and welded. , 19 are fixed. A pair of left and right first mounting portions 19a and 19a projecting in the vehicle width direction and a second mounting portion 19b extending rearward are formed at the rear portion of each bumper beam extension 19, and the first mounting portions 19a and 19a Two bolts 20, 20 that penetrate the lower part pass through the front surface of the bent part 12 b of the upper member 12 and are fastened to the weld nuts 21, 21, and two bolts that penetrate the upper part of the first attachment parts 19 a, 19 a 22 and 22 pass through the flanges 11 a and 11 a at the front end of the front side frame 11 and are fastened to the weld nuts 23 and 23. One bolt 24 that penetrates the second attachment portion 19 b penetrates the upper surface of the front side frame 11 and is fastened to the weld nut 25. The left and right ends of the bumper beam 26 are supported on the front surfaces of the bumper beam extensions 19 and 19.

  As shown in FIGS. 1 to 3, the radiator support 27 includes a pair of left and right radiator side stays 28, 28 that extend in the vertical direction, a radiator lower stay 29 that connects the lower ends of both the radiator side stays 28, 28, and both radiators. A radiator upper stay 30 that connects between the upper ends of the side stays 28 and 28 is formed in a square frame shape, and the middle part in the vertical direction of both the radiator side stays 28 and 28 is a vehicle of both bumper beam extensions 19 and 19. A pair of left and right extension portions 30a, 30a of the radiator upper stay 30 that is connected to the inner surface in the width direction and extends obliquely rearward from the upper ends of the radiator side stays 28, 28 are upper surfaces of intermediate portions in the front-rear direction of the upper members 12, 12. Connected to

  The radiator 31 includes a lower tank 32, an upper tank 33, and a core 34 that connects both the tanks 32, 33, and the lower surface of the lower tank 32 has two rubber bush joints 35, 35 provided on the radiator lower stay 29. The upper surface of the upper tank 33 is supported by rubber bush joints 38, 38 provided on a pair of left and right radiator support brackets 37, 37 fixed to the front surface of the radiator upper stay 30 by bolts 36, 36.

  As described above, the upper surfaces of the front ends of the upper members 12 and 12 are overlapped with each other on the lower surfaces of the front ends of the front side frames 11 and 11, and the bumper beam extensions 19 and 19 are connected to the front surfaces of the connecting portions. Since the bumper beam 26 is supported, the collision load input to the bumper beam 26 at the time of a frontal collision of the vehicle can be dispersed and effectively absorbed by both the front side frames 11 and 11 and the upper members 12 and 12. . At this time, since the bent portions 12b and 12b of the upper members 12 and 12 are bent and deformed rearward of the vehicle body to absorb the impact with respect to the collision load, the impact absorbing effect can be enhanced.

  In addition, since the front portion of the subframe 13 is coupled to the lower surfaces of the bent portions 12b and 12b at the front ends of the upper members 12 and 12, special mounting for supporting the subframe 13 on the lower surfaces of the front side frames 11 and 11 is performed. Not only is it unnecessary to provide a bracket, the number of parts can be reduced and the structure can be simplified, but also the collision load can be distributed to the sub-frame 13 and absorbed more effectively.

  Also, since the pair of left and right radiator side stays 28, 28 of the radiator support 27 are supported on the inner surfaces of the pair of left and right bumper beam extensions 19, 19, which are opposed to each other, the bumper beam extension pushed by the bumper beam 26 at the time of a light vehicle collision. Even when 19 and 19 are retracted, the radiator 31 can be retracted together with the radiator support 27 supported by the bumper beam extensions 19 and 19, and the damage can be minimized.

  As shown in FIG. 6A, when the host vehicle having the vehicle body front structure according to the present embodiment collides front with another vehicle, both upper members 12 are placed on the lower surfaces of the front ends of both front side frames 11, 11. , 12 are overlapped with each other so that the height H at which a load from the front can be received becomes large. For example, the position of the bumper beam 41 of the other vehicle is the front side frame 11 of the own vehicle. , 11, the shock absorption effect can be ensured by preventing the frames of both vehicles from passing each other.

  Further, as shown in FIG. 6B, when the host vehicle having the vehicle body front structure according to the present embodiment collides with another vehicle in a side collision, for example, the position of the side sill 42 of the other vehicle is the front side of the host vehicle. Even if it is lower than the frames 11, 11, the shock absorption effect can be ensured by preventing the frames of both vehicles from passing each other.

  Further, since the front portions of the upper members 12 and 12 coupled to the front ends of the front side frames 11 and 11 are provided with bent portions 12b and 12b extending in the vehicle width direction, the coupled portions of the front side frames 11 and 11 are provided. A collision load can be received with the width L (see FIG. 3) of the bent portions 12b, 12b wider than the width. Therefore, even in the case of an offset collision with another vehicle, the impact absorbing effect can be ensured by receiving the collision load in a wide area in the left-right direction.

  By the way, when the phenomenon that the front part of the front side frames 11 and 11 vibrate in the vehicle width direction occurs, there is a problem that the steering stability is lowered. The degree of the intensity of this vibration is represented by an index called inertance. Inertance is defined as A / F when acceleration A occurs at another point away from the excitation point when a periodic excitation force with amplitude F is input to the elastic body.

  In the conventional structure, since the front end of the front side frame and the front end of the upper member are connected via a connecting member extending in the vehicle width direction, the frame rigidity of the front part of the vehicle body is reduced and inertia is increased. There was a problem that adversely affected the maneuvering stability performance. However, according to the present embodiment, the bent portions 12b and 12b corresponding to the conventional connecting member are integrally formed as a part of the upper members 12 and 12, so that the inertance can be reduced and the steering stability performance of the vehicle can be reduced. Can be increased.

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 .

Perspective view of the front of the vehicle body 2 direction view of FIG. 3-3 arrow view of FIG. 2-2 line view of FIG. Perspective view of the part that connects the bumper beam extension to the front side frame and upper member Action diagram at the time of collision

11 Front side frame 12 Upper member 12b Bending portion 13 Subframe 19 Bumper beam extension 26 Bumper beam 27 Radiator support

Claims (3)

In a vehicle body front part structure for connecting a front end of a pair of left and right front side frames (11) extending in the longitudinal direction of the vehicle body and a front end of a pair of left and right upper members (12) extending downward from the front end of the front pillar to the front of the vehicle body,
The front portion of the upper member (12) is bent inward in the vehicle width direction by hydroforming to form a bent portion (12b), and the upper surface of the distal end of the bent portion (12b) extending in the vehicle width direction is the front side. The upper surface of the front end of the frame (11) is overlapped and joined in the vertical direction ,
A bumper beam extension (19) fixed so as to straddle the joint between the front side frame (11) and the upper member (12) is projected toward the front of the vehicle body, and the front end of the bumper beam extension (19) A vehicle body front part structure characterized by supporting a bumper beam (26) . Characterized in that said supporting the front portion of the sub-frame on the lower surface of the bent portion (12b) (13), the vehicle body front structure according to claim 1 before Symbol upper member (12). Characterized in that supporting the radiator support (27) before Symbol bumper beam extension (19), the vehicle body front structure according to claim 1 or claim 2.

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