JPH0565075A - Front body structure of car - Google Patents

Abstract

PURPOSE:To prevent the cabin space from being influenced by retreat of the engine at the time of relative displacement by separating a cross-member and a center member coupled with the cross-member to support the engine from each other when they make relative displacement in the direction fore and aft of the car body. CONSTITUTION:An engine 1 is mounted in the front of a car body, and a center member 2 is arranged in the part below it. A side frame 3 is installed on each side of the car body, and a wheel apron frame 4 is installed in a position over its outside. A branch frame 7 is installed at the foremost of the side frame 3, and a cross-member 8 is arranged on the inside of its foremost extremity and connected with the tip of the center member 2. The two members 2, 8 are coupled together by fitting a bolt, etc., 23 in a long hole provided in a bracket 22. When an external force acts on a bumper 6, the two members 2, 8 are disengaged, and the engine 1 is dropped, and thereby the cabin space 9 is precluded from ill influence of the retreat of the engine 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front body structure of an automobile, and more particularly to a structure of a front frame portion.

[0002]

2. Description of the Related Art It is conventionally known to provide a branch frame below a side frame of an automobile. A vehicle body structure provided with such a branch frame is, for example,
No. 115771. By providing the branch frame in this way, the bumper can be supported below and the height of the front portion of the vehicle body can be reduced, as compared with the case where the front end of the side frame supports the bumper. Therefore, it is possible to meet the design requirement that restricts the height of the front structure of the vehicle body.

Further, in a vehicle body structure of an automobile, when an impact force is applied from the front portion of the vehicle body toward the rear, there is a possibility that the engine may move rearward to narrow the vehicle interior space. In order to avoid such a situation, when an impact force is input to the vehicle body from the front, the engine is moved downward rather than rearward so that the influence on the vehicle interior space as described above is minimized. It is known in the art to construct a front structure. In this case, the impact force transmitted to the side frame through the bumper is transmitted to the cross member connecting the side frames, and the cross member and the center member supporting the engine connected to the cross member are separated by using the impact force. Then, this moves the engine downward.

[0004]

[Problem to be Solved] However, in a structure in which the front end of the side frame is vertically branched, the impact force input through the bumper may be dispersed and transmitted to the vertically branched tip. There is a risk that the engine will not move downward when it receives the impact force as described above.

In view of the above circumstances, the present invention is capable of reliably moving the engine downward when an impact force is input to the vehicle body from the front, and therefore can prevent an adverse effect on the vehicle interior space. An object is to provide a front body structure. Another object of the present invention is to increase the degree of freedom in designing a vehicle body.

[0006]

In order to solve the above problems, the present invention is configured as follows. A front vehicle body structure for an automobile according to the present invention includes a pair of side frames extending in the front-rear direction on both sides of the vehicle body, and branches downward near the front end portions of the side frames and beyond the front end portions of the side frames. A branch frame extending forward, a cross member extending laterally of the vehicle body and having both ends joined to the front end of the branch frame, and a center member supporting the engine having the front end extending forward and backward of the vehicle body joined to the cross member. And a separating member that separates the cross member and the center member from each other when they are relatively displaced at least in the front-rear direction of the vehicle body.

In the preferred embodiment, a bumper is attached to the front end of the bifurcation frame. In another preferred aspect, the radiator is supported by the bifurcation frame.

[0008]

According to the present invention, the rearward impact force input to the front end of the vehicle body first acts on the front end of the branch frame projecting more forward than the front end of the side frame. Since the front end of the center member supporting the engine is attached to the branch frame, the impact force input to the branch frame is further transmitted to the cross member. The cross member is displaced rearward relative to the center member, and the center member is separated from the cross member by the separating means.
As a result, the center member moves downward together with the engine due to the weight of the engine. That is, when an impact force from the front to the rear is input to the front end of the vehicle body, the engine moves downward without moving backward.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIGS. 1 to 3, the front part of the vehicle body is
A horizontally-mounted engine 1 is arranged, and a center member 2 extending in the front-rear direction is provided below the engine 1 at substantially the center of the vehicle body. Also, on both sides of the car body,
Similarly, a side frame 3 extending in the front-rear direction is provided. Further, a wheel apron frame 4 extending in the front-rear direction is provided slightly outside and above the side frame 3. The wheel apron frame 4 extends almost to the position of the headlight 5. Side frame 3
Has reached the rear of both ends of the bumper 6, and the branch frame 7 branches downward at the tip to form a bifurcated shape. The branch frame 7 extends downward and forward from the branch point from the side frame 3 and then curves forward and extends further forward than the front end of the side frame 3. Both ends of a laterally extending cross member 8 are connected to the inside of the front end of the branch frame 7. The tip of the center member 2 is connected to the cross member 8. The rear ends of the members 2, 3 and 4 extending in the respective front-rear directions are provided in the vehicle compartment 9
It extends to the dash panel 11 that separates the engine room 10 from the engine room 10. The upper end of the dash panel 11 is connected to a cowl box 13 having a closed cross-section structure that supports the lower end of the windshield 12. Further, the engine room 10 is shut off from the outside by the bonnet 14,
The rear end of the hood 14 is supported by the cowl box 13. Further, a radiator is arranged above the cross member 8, and both ends of the radiator extend to above the side frame 15 and are supported thereby.

The engine 1 includes a center member 2 through bushes 16 and 17 supported by a tubular guide in the front-rear direction and brackets 18 and 19 supporting the bushes.
Supported by. The wheel apron frame 4 is also supported in the horizontal direction via the bracket 20 and the bush 21. As shown in FIGS. 4 and 5, the cross member 8 and the center member 2 have a bracket 22 fixed to the cross member 8 and a bolt and nut 23 attached to the center member, and an elongated hole 24 provided in the bracket 22. The two are connected by engaging via. As shown in FIG. 6, the elongated hole 24 extends in the front-rear direction, and the front portion is larger than the nut 23 and the rear portion is smaller than the nut 23. Usually nut 2
3 is located at the rear portion of the elongated hole 24, and the nut 23 and the bracket 22 are engaged with each other. Then, when the cross member 8 is displaced rearward relative to the center member 2 and the nut 23 moves to the large opening portion in front of the elongated hole 24, the engagement between the cross member 8 and the center member 2 is released. It has become.

The bumper 6 is located in front of the branch frame 7 of the side frame 3 and is supported by the branch frame 7. In the above structure, the state change when an external force acts on the front of the automobile body will be described. For example, when an external force directed rearward is input to the bumper 6 as shown in FIG. 7A and the external force is large, the bumper is first crushed as shown in FIG. 7B.
Next, the external force acts on the tip of the branch frame 7 via the bumper 6 to displace the branch frame 7 rearward. As a result, the cross member 8 supported by the branch frame 7 moves rearward with respect to the center member 2, and the engagement between the cross member 8 and the center member 2 is released as described above, and the center member 2 is released. Falls due to the weight of the engine 1. When an external force is further applied after that, as shown in FIG.
After the radiator 14 is deformed as shown in (c), an external force is also input to the tip of the side frame 3.

As described above, in the structure of the present invention, the bumper 6
When an external force is applied to the side frame 3, it is first input to the branch frame 7 extending before the tip of the side frame 3.
Then, the branch frame 7 and the cross member 8 are displaced to act on the tip of the side frame 3 only after the engagement between the cross member 8 and the center member 2 is released. Therefore, the engine 1 supported by the center member 2 is surely dropped downward at the initial stage when the external force is input. Therefore, the vehicle interior space 9 is not affected by being moved backward by the external force.

[0013]

[Effects] According to the present invention, it is possible to reliably prevent the engine from moving backward when an external force is applied to the front of the vehicle body to the rear, and to prevent the adverse effect on the vehicle interior space. You can Further, since the radiator is supported by the branch frame of the side frame, the radiator can be formed in a laterally long shape, the height can be suppressed, and the design requirement for lowering the vehicle body can be met. ..

[Brief description of drawings]

FIG. 1 is a plan view of a front vehicle body structure according to an embodiment of the present invention,

2 is a sectional view taken along the line AA of the vehicle body structure shown in FIG.

3 is a sectional view taken along the line BB of the vehicle body structure shown in FIG.

FIG. 4 is a perspective view of a connecting portion between a cross member and a center member,

5 is a sectional view taken along line CC of FIG.

FIG. 6 is a plan view of the opening of the bracket,

FIG. 7 is a deformation state diagram when an external force is input to the front body structure.

[Explanation of symbols]

 1 Engine 2 Center Member 3 Side Frame 4 Wheel Apron Frame 5 Headlight 6 Bumper 7 Branch Frame 8 Cross Member 9 Vehicle Space 10 Engine Room 11 Dash Panel 12 Front Wind Glass 13 Cowl Box

Claims (1)

[Claims] 1. A pair of side frames that extend in the front-rear direction on both sides of a vehicle body, and a branch frame that branches downward near the front end of the side frame and extends further forward beyond the front end of the side frame. A cross member that extends in the lateral direction of the vehicle body and has both ends joined to the front end of the branch frame; a center member that extends in the vehicle longitudinal direction and has a front end that is joined to the cross member to support the engine; And at least a separating means for separating the two when they are relatively displaced in the longitudinal direction of the vehicle body.