JPH05213151A - Car-body front structure for automobile - Google Patents

Abstract

PURPOSE:To provide a car-body front structure of an automobile, in which a stabilized action of an air bag device is expected, and which is capable of coping with the change in surrounding structures to obtain a desired acceleration wave form. CONSTITUTION:A pipe 9 is arranged and installed in the inside of a front side member 4, and one end part 9a of the pipe 9 is bolted integrally to the front side member in a cantilevered state through a bracket 7 with bolts 8. The pipe 9 is fixed to a lower member 2 of rigid-body construction in the cantilevered state, and when a collision occurs, the other end part 9b of the pipe 9 receives collision-energy to be vibrated to produce an acceleration wave form. The acceleration wave form can be obtained without being influenced by surrounding structures, since one end part 9a of the pipe 9 is fixed to the lower member 2. Thus, when shape, etc., are once set to obtain a desired acceleration wave form, there is no need to change the pipe 9 even when the surrounding structures are changed. Since the adequate acceleration wave form can be obtained, a stabilized action of an air bag device can be expected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body front structure provided with an airbag device.

[0002]

2. Description of the Related Art In recent years, an automobile has been provided with an air bag device for alleviating obstacles caused by a secondary collision at the time of a collision. An airbag device is generally composed of a collision detection sensor, a gas generator, and a bag.The collision detection sensor detects an acceleration waveform generated on the front side member at the time of an initial collision, and collates the acceleration waveform with a reference acceleration waveform. For example, when the amplitude value of the acceleration waveform is larger than the amplitude value of the reference amplitude waveform, the gas generator is ignited (ignited) to inflate the bag, and the inflation of the bag restrains the occupant and the occupant is damaged. I try to prevent it.

In this case, the ignition timing of the gas generator largely depends on the acceleration waveform. In order to obtain this acceleration waveform, for example, in the vehicle body 1 shown in FIG. 4, the lower member 2 of the lower member 2 as shown in FIG. The following measures are taken with respect to the front side member 4 formed by joining the upper member 3 to the upper portion and forming the closed shape in cross section. That is, as shown in FIGS. 6 and 7, the front side member 4 is divided into sections to provide the lean reinforcement 5 so that a desired acceleration waveform can be obtained when the vehicle body 1 collides. The gas generator is ignited by determining the ignition timing using the acceleration waveform.

As shown in FIG. 7, in the front side member 4, the lower member 2 is superposed on the sub-frame 6, and together with the bracket 7 arranged on the upper portion of the lower frame 2, the front side member 4 can be tightened together by bolts 8. It is fixed.

As an example of the front body of the vehicle,
There is one disclosed in Japanese Patent No. 58-126575. A front vehicle body of this vehicle is configured by fixing a pipe to a front frame and fitting a round bar with a die for absorbing energy so as to be housed in the pipe.

[0006]

By the way, as shown in FIGS. 6 and 7, when the reinforcement 5 is provided and a desired acceleration waveform is obtained, a large number of reinforcements 5 having different sizes, plate pressures and the like are provided. It is necessary to prepare and obtain the desired acceleration waveform by exchanging the front side members 4 with each other, and it is not easy to obtain an appropriate acceleration waveform.

Further, even if the desired acceleration waveform is obtained once, if there is a change in the surrounding structure such as a change in the layout of the surroundings or a change in the plate thickness of the surrounding members, the above-mentioned process is repeated according to the change in the structure. Many Lean Force 5
It was necessary to repeatedly perform the adjustment work using, and it was not possible to appropriately cope with the structural changes in the surroundings.

The plate thickness of the reinforcement 5 is
The acceleration waveform is not greatly influenced, and in contrast, the acceleration waveform is largely dependent on the lower member 2 of the front side member 4.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a front body of an automobile capable of easily coping with changes in the surrounding structure in obtaining a desired acceleration waveform.

[0010]

In order to achieve the above object, the present invention provides a front side member having a closed cross-section formed by joining an upper member to an upper portion of a lower member to form a subframe at the lower member. In a vehicle body of an automobile in which both are fixed by bolts, a pipe oriented in the longitudinal direction of the front side member is arranged inside the front side member, and one end of the pipe is attached to the bolt through a bracket. It is characterized by being integrally attached in a cantilevered state by tightening together.

[0011]

With this structure, since the pipe is cantilevered and fixed to the lower member of the rigid structure, when there is a collision, the tip of the pipe vibrates due to the collision energy, and the acceleration is accelerated. Generate a waveform. This acceleration waveform can be obtained without being affected by the surrounding structure because the base end of the pipe is fixed to the lower member of the rigid structure.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A front vehicle body of an automobile according to an embodiment of the present invention will be described below with reference to FIGS. The same members as those shown in FIGS. 4 to 7 are designated by the same reference numerals, and the description thereof will be omitted.

Inside the front side member 4, a pipe 9 is arranged in the longitudinal direction of the front side member 4. One end 9a of the pipe 9 is fixed to the lower member 2 together with the sub-frame 6 by fastening the bolt 8 together via the bracket 7. By fixing the pipe 9 in this manner, the pipe 9 is in a cantilever state with the other end 9b extending in front of the vehicle body 1. An auxiliary bracket 10 is interposed between one end 9a of the pipe 9 and the lower member 2. In the figure, 11 is a front cross member rear, and 12 is a front cross member front.

In the vehicle body front structure constructed as described above, since the subframe 6 is made of a rigid material, the vehicle body 1 does not absorb collision energy when the vehicle collides, and the collision energy is not absorbed. Energy is transferred to the pipe 9. Since the pipe 9 is fixed to the lower member 2 by fixing the sub-frame 6 via the bracket 5 in a cantilevered state, the other end portion 9b generates a velocity waveform according to the collision energy. This acceleration waveform is obtained by vibrating the other end 9b of the pipe 9 whose one end 9a is fixed to the lower member 2 of the rigid structure, and therefore is not affected by the surrounding structure. . Therefore, even if the surrounding structure is changed, it is not necessary to change the shape of the pipe 9 in order to obtain a desired acceleration waveform.

By providing the collision detection sensor capable of inputting the acceleration waveform, the gas generator is ignited (ignited) and the bag is inflated using the acceleration waveform without being affected by the surrounding structure. be able to. As described above, the acceleration waveform generated by the pipe 9 can be used to affect the operation of the airbag device without being affected by the surrounding structure. There is no need to change the shape, etc., and the degree of freedom in changing the structure is correspondingly great.

[0016]

According to the present invention, since the pipe is cantilevered and fixed to the lower member of the front side member of the rigid structure, when a collision occurs, an acceleration waveform is generated without being affected by the surrounding structure. It will be. As a result, once the shape of the pipe or the like is set and the desired acceleration waveform is obtained, it is not necessary to change the pipe in response to changes in the surrounding structure. Further, as described above, since an appropriate acceleration waveform is obtained, it is possible to expect stable operation of the airbag device.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a front body of an automobile according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line CC of FIG.

FIG. 3 is a sectional view taken along the line DD of FIG.

FIG. 4 is a perspective view showing a vehicle body of an automobile.

5 is a cross-sectional view taken along the line AA of FIG.

6 is a sectional view taken along the line AA of FIG. 4 when the reinforcement is attached to the front side member.

FIG. 7 is a sectional view taken along line BB of FIG. 4 when the reinforcement is attached to the front side member.

[Explanation of symbols]

 2 Lower member 3 Upper member 4 Front side member 7 Bracket 8 Bolt 9 Pipe 9a One end

Claims (1)

[Claims] 1. A vehicle body in which an upper member is joined to an upper part of a lower member to form a front side member having a closed cross-section and is superposed on a subframe at a portion of the lower member, and both of which are fixed by bolts, A pipe oriented in the longitudinal direction of the front side member is disposed inside the front side member, and one end of the pipe is integrally attached in a cantilever state by co-tightening the bolt through a bracket. The characteristic front structure of the car body.