JP6858659B2 - Vehicle shock absorber - Google Patents

Description

The present invention relates to a vehicle shock absorber provided at a portion of a vehicle that receives a collision load.

As a shock absorbing device for a vehicle, a device that projects a collision load receiving member such as a bumper installed at the front end of the vehicle forward immediately before a collision with a colliding object has been developed (see, for example, Patent Document 1). Specifically, a stretchable stretchable body is provided between the collision load receiving member and the vehicle structure, and an inflator that supplies gas to the stretchable body is provided. Normally, the stretchable body is contracted and the collision load receiving member is located at the front end of the vehicle structure, but the inflator operates immediately before the collision, and the stretchable body expands and stretches due to the gas generated from the inflator. Then, the collision load receiving member is projected forward away from the vehicle structure. At the time of a collision, gas is gradually released from the stretchable body that has been expanded by receiving the collision load, the stretchable body is contracted, and the collision energy is absorbed.

Japanese Unexamined Patent Publication No. 2010-241240

In order to absorb the collision energy at the time of collision in a desirable form, it is necessary to gradually contract the stretchable body with the lapse of time after the collision. Therefore, it is necessary to gradually contract and deform the stretchable body itself regardless of the pressure in the stretchable body, or to gradually reduce the gas pressure in the stretchable body. However, it is difficult to gradually contract and deform the stretchable body itself. This is because the stretchable body is stretched from the initial contracted state before the collision and contracted again after the collision. Therefore, the contraction deformation after the collision is easily performed with a relatively small load due to the Bauschinger effect, and the collision energy cannot be sufficiently absorbed. On the other hand, gradually reducing the gas pressure in the stretchable body requires high-precision control, and must be performed in a state where there is no extra gas leakage from the stretchable body, which raises the problem of high costs. is there.

In view of such a problem, an object of the present invention is to expand a stretchable body immediately before a collision to project a collision load receiving member in a direction facing the collision, and after the collision, the stretchable body is contracted to absorb collision energy. The purpose of the shock absorbing device is to increase the strength of the stretchable body at the time of contraction after collision to secure the amount of collision energy absorbed by the stretchable body without depending on the gas pressure control in the stretchable body.

The first invention of the present invention is a collision load receiving member provided so as to receive a collision load in a vehicle structure of a collision-affected portion of a vehicle body and transmit the collision load from a collision object to the vehicle structure, and the collision. A stretchable body provided by forming a space between the load receiving member and the vehicle structure and having a deformable portion that can expand and contract in the direction in which the impact load receiving member receives a collision load, and the stretchable body before the collision. It is provided with an inflator that supplies gas to the space to expand the volume of the space and extend the stretchable body, and when the collision load receiving member receives a collision load, the deformed portion of the stretchable body contracts. It is a shock absorber for vehicles that absorbs collision energy. The deformed portion of the stretchable body includes a material that is cured by receiving the heat generated by the inflator.

In the first invention, the collision-affected portion may be any of the front, rear, side portions, roof and the like of the vehicle body. It should be noted that the first invention does not prevent the implementation of gas pressure control in the telescopic body.

The gas generated by the inflator is considered to be hot. According to the first invention, the deformed portion of the stretchable body is cured by receiving the heat of the gas. Therefore, the strength of the stretchable body at the time of contraction after collision is increased, and the amount of collision energy absorbed by the stretchable body can be secured without depending on the gas pressure control in the stretchable body.

In the second invention of the present invention, in the first invention, the deformed portion of the stretchable body includes a metal that is hardened by receiving heat generated by an inflator.

According to the second invention, the deformed portion of the stretchable body is hardened and hardened by receiving the heat of the gas generated by the inflator. Therefore, the strength of the stretchable body at the time of contraction after the collision is increased, and the amount of collision energy absorbed by the stretchable body can be secured.

In the third invention of the present invention, in the first invention, the deformed portion of the stretchable body includes a resin that is cured by receiving heat generated by an inflator.

According to the third invention, the deformed portion of the stretchable body receives the heat of the gas generated by the inflator and the resin is thermoset. Therefore, the strength of the stretchable body at the time of contraction after the collision is increased, and the amount of collision energy absorbed by the stretchable body can be secured.

In the fourth aspect of the present invention, in the second aspect of the present invention, the telescopic body includes an exhaust valve that is opened to the atmosphere when the pressure in the space of the stretchable body becomes a predetermined pressure or more.

According to the fourth invention, when the gas pressure of the stretchable body increases after the expansion is completed, the exhaust valve is opened and the gas pressure is lowered, and at the same time, the temperature of the stretchable body is rapidly cooled as the gas pressure is lowered. Therefore, the deformed portion of the stretchable body is hardened and easily hardened. Therefore, the strength of the stretchable body at the time of contraction after the collision is increased, and the amount of collision energy absorbed by the stretchable body can be secured.

In any one of the first to fourth inventions, the fifth aspect of the present invention divides the stretchable body into a fixing portion side to the vehicle structure and a collision load receiving member side, and the fixing portion. The side has higher strength or hardness than the collision load receiving member side.

According to the fifth invention, the strength or hardness on the fixed portion side is increased. Therefore, the possibility that the fixed portion side of the stretchable body is buckled and deformed by the collision load is suppressed. Therefore, the stretchable body can stably absorb the collision energy.

It is a top view which shows the bumper structure of the front part of a vehicle to which 1st Embodiment of the shock absorbing device for a vehicle of this invention is applied. It is a partial perspective enlarged perspective view of the shock absorption unit in 1st Embodiment. FIG. 3 is an enlarged view of a cross section taken along line III-III of FIG. FIG. 3 is a cross-sectional view similar to FIG. 3, showing a state in which gas is supplied from the inflator and the bumper is moved forward. It is a cross-sectional view similar to FIG. 3, and shows a state in which the exhaust valve is open to the atmosphere. It is a cross-sectional view similar to FIG. 3, and shows a state in which the bumper is being moved backward by receiving a collision load. It is an enlarged sectional view of the exhaust valve in 1st Embodiment. FIG. 5 is a cross-sectional view similar to FIG. 5 showing a stretchable body according to a second embodiment of the present invention. FIG. 5 is a cross-sectional view similar to FIG. 5 showing a stretchable body according to a third embodiment of the present invention.

<Overall configuration of the first embodiment>
FIGS. 1 to 3 show the configuration of the first embodiment of the present invention. The first embodiment is an example in which the shock absorbing device of the present invention is applied to a front bumper portion for an automobile. In each figure, the arrows indicate the directions of the device when mounted on the automobile. In the following description, the description regarding the direction shall be made with reference to this direction.

As shown in FIG. 1, the bumper reinforcement 1 of the front bumper, which is a collision load receiving member, is fixed to the front ends of the front members 2L and 2R arranged on the left and right sides of the vehicle body as the vehicle structure of the collision-affected portion of the vehicle body. .. Therefore, the collision load applied to the front bumper at the time of a vehicle front collision is received by the front members 2L and 2R via the bumper information 1.

As shown in FIGS. 2 and 3, the front end portion of the front member 2L is provided with a shock absorbing unit 10 which is a feature portion of the present invention. Although only the front member 2L is shown here and the front member 2R is not shown, the front members 2L and 2R are provided with a shock absorbing unit 10 having the same structure.

<Structure of shock absorbing unit 10>
The shock absorbing unit 10 is fixed to a cover body 13 which is a bottomed cylindrical body (hereinafter, also referred to as a container shape) and inside the cover body 13 and expands and contracts in the front-rear direction (direction to receive the collision load) by receiving a collision load. A container-shaped telescopic body 11 having a bellows-shaped deformed portion 11a made possible, an inflator 12 fixed inside the telescopic body 11, and an exhaust valve 15 provided in the telescopic body 11 together with the inflator 12. Be prepared.

The cover body 13 integrally includes a container-shaped container portion 13a and a flange 13b formed over the entire circumference of the container portion 13a on the opening side. The cover body 13 is made of steel plate. The container portion 13a is inserted inside the front end of the front member 2L having a closed cross-sectional structure, and the flange 13b is fixed to the front end of the front member 2L via a top member 21 which is a ring-shaped disk.

<Structure of elastic body 11>
The stretchable body 11 has a flange 13b formed over the entire circumference of the container shape on the opening side. The telescopic body 11 is arranged so as to be a container that overlaps with the container portion 13a of the cover body 13, and the flange 11b is arranged so as to overlap the front side of the flange 13b of the cover body 13. The stretchable body 11 is made of a steel plate having a thickness thinner than that of the cover body 13, and is a steel plate that is hardened by the heat of the gas generated by the inflator. Specifically, the stretchable body 11 uses a hot stamping material that has been press-molded by heating. Further, the bottom portion 11c of the stretchable body 11 is joined to the bottom portion of the cover body 13 by an appropriate means.

A lid 14 is covered on the opening side of the stretchable body 11. The rear side of the lid 14 is overlapped and fixed to the front side of the flange 11b of the telescopic body 11. Therefore, the opening of the telescopic body 11 is closed by the lid body 14 to form one space inside. Further, a bumper reinforcement 1 is fixed to the lid body 14 on the front side thereof.

In this way, the telescopic body 11 is housed in the cover body 13 and fixed to the front end of the front member 2L. Moreover, the cover body 13 is housed in the closed space of the front member 2L. Therefore, as shown in FIG. 3, when the stretchable body 11 is in the contracted state, the stretchable body 11 is inside the cover body 13 and does not protrude from the front member 2L. Therefore, the design of the front member 2L and the bumper reinforcement 1 can be made common with the case where the telescopic body 11 is not provided.

<Structure of inflator 12>
The inflator 12 is a known inflator similar to the inflator used in the occupant protection airbag device, and is configured to be ignited by being energized to generate gas. The inflator 12 is appropriately fixed to the bottom portion 11c of the stretchable body 11 by means. The inflator 12 is electrically connected so as to operate by being connected to a power source (not shown) when a known collision predicting means (not shown) predicts a front collision of the vehicle. Therefore, the inflator 12 generates gas when activated, and supplies the gas into the stretchable body 11.

<Structure of exhaust valve 15>
The exhaust valve 15 is configured to receive the gas pressure generated by the inflator 12 in the space of the telescopic body 11 and open to the atmosphere when the gas pressure becomes equal to or higher than a preset predetermined pressure. Specifically, as shown in FIG. 7, the exhaust valve 15 is a hollow box body fixed to the bottom portion 11c of the telescopic body 11, and a through hole 15b is formed in the surface of the telescopic body 11 in contact with the bottom portion 11c. A pair of fragile portions 15a are formed on the opposite surface thereof. The fragile portion 15a is formed so as to be broken when the pressure in the space of the stretchable body 11 becomes equal to or higher than a predetermined pressure. Further, through holes 11d and 13c are formed in the bottom portion 11c of the telescopic body 11 and the bottom portion of the cover body 13 corresponding to the through holes 15b, respectively, and when the fragile portion 15a is broken, these through holes 15b , 11d, 13c, and atmospheric pressure is supplied into the space of the telescopic body 11.

<Operation of the first embodiment>
When a vehicle collision is predicted, the inflator 12 is activated, and the inflator 12 generates gas, the stretchable body 11 expands (extends), and the bellows of the deformed portion 11a stretches to expand the bumper information 1 as shown in FIG. Is projected forward. At this time, the temperature of the gas generated by the inflator 12 is about 600 ° C., but the temperature is raised to about 700 to 800 ° C. by configuring the structure to increase the pressure in the telescopic body 11.

As shown in FIG. 5, when the expansion of the expansion / contraction body 11 is completed, the pressure in the space of the expansion / contraction body 11 increases to a predetermined pressure or more, and the gas is released to the atmosphere through the exhaust valve 15, the expansion / contraction body 11 The pressure and temperature in the space drops rapidly. Due to such a sudden change in temperature, the steel plate forming the deformed portion 11a of the stretchable body 11 is hardened. Therefore, the hardness and strength of the deformed portion 11a of the stretchable body 11 are increased.

After that, when the collision object collides with the bumper and the bumper reinforcement 1 is pushed backward as shown in FIG. 6, the stretchable body 11 contracts and absorbs the collision energy.

<Effect of the first embodiment>
As described above, when the stretchable body 11 absorbs the collision energy while contracting, the deformed portion 11a of the stretchable body 11 is hardened and strengthened by quenching, and the load at the time of deformation is increased. Therefore, the amount of energy absorbed required to absorb the collision energy can be secured.

<Structure / operation of the second embodiment>
FIG. 8 shows a second embodiment of the present invention. The feature of the second embodiment as compared with the first embodiment is that the plate pressure of the steel plate constituting the stretchable body 11 is changed depending on the portion. The other configurations are exactly the same, and the same part will not be described again.

As shown in FIG. 8, in the second embodiment, the stretchable body 11 is divided into two regions in the front-rear direction (direction in which the collision load is received). Of the two regions, the plate thickness of the fixed portion side (rear side) 11e to the vehicle structure is thicker than that of the collision load receiving member side (front side) 11f opposite to the region. For example, the plate thickness of the collision load receiving member side 11f is 2 mm, while the plate thickness of the fixed portion side 11e is 2.6 mm. The fixed portion side 11e and the collision load receiving member side 11f may be integrally formed of one material or may be formed by joining different materials. In the case of the former forming method, a tailored rolled blank steel sheet can be used. Further, in the case of the latter forming method, a tailored blank bonded steel sheet can be used. As the welding joint in this case, laser welding and plasma arc welding can be used.

Therefore, the fixed portion side 11e has a higher buckling strength than the impact load receiving member side 11f, and the possibility that the fixed portion side 11e buckles when the impact load is applied is suppressed. In particular, when the collision load input to the telescopic body 11 is inclined vertically or horizontally from the front in the front-rear direction, stress is concentrated on the fixed portion side 11e and buckling deformation is likely to occur. Since the buckling strength is increased, such buckling deformation is suppressed. Therefore, the stretchable body 11 can stably absorb the collision energy.

<Structure / operation of the third embodiment>
FIG. 9 shows a third embodiment of the present invention. The feature of the third embodiment as compared with the first embodiment is that the material of the steel plate constituting the stretchable body 11 is changed depending on the portion. The other configurations are exactly the same, and the same part will not be described again.

As shown in FIG. 9, in the third embodiment, of the two regions of the stretchable body 11, the fixed portion side 11e is made of a material having a higher buckling strength than the collision load receiving member side 11f. For example, the strength of the impact load receiving member side 11f after quenching is 1.5 giganewton, whereas the strength of the fixed portion side 11e after quenching is 1.8 giganewton. The fixed portion side 11e and the collision load receiving member side 11f can be configured by using a tailored blank bonded steel plate. As the welding joint in this case, laser welding and plasma arc welding can be used.

Therefore, the fixed portion side 11e has a higher buckling strength than the impact load receiving member side 11f, and the possibility that the fixed portion side 11e buckles when the impact load is applied is suppressed. In particular, when the collision load input to the telescopic body 11 is inclined vertically or horizontally from the front in the front-rear direction, stress is concentrated on the fixed portion side 11e and buckling deformation is likely to occur. Since the strength is increased, such buckling deformation is suppressed. Therefore, the stretchable body 11 can stably absorb the collision energy.

<Other embodiments>
Although the specific embodiments have been described above, the present invention is not limited to their appearance and configuration, and various changes, additions, and deletions can be made. For example, in the above embodiment, the deformed portion of the stretchable body is made of a hardenable steel plate, but it may be made of a hardenable aluminum material or a thermosetting resin. Further, in the above embodiment, an example is shown as an exhaust valve, but it can be replaced with various known pressure valves. Furthermore, in the above embodiment, the present invention is applied to an automobile, but it can be applied to various vehicles other than the automobile.

1 Vampari information (collision load receiving member)
2L, 2R front member (vehicle structure of collision part)
21 Top member 10 Shock absorption unit 11 Telescopic body 11a Deformation part 11b Flange 11c Bottom part 11d Through hole 11e Fixed part side 11f Collision load receiving member side 12 Inflator 13 Cover body 13a Container part 13b Flange 13c Through hole 14 Lid body 15 Exhaust valve 15a Vulnerable part 15b through hole

Claims (2)

A collision load receiving member that is provided so as to receive the collision load in the vehicle structure of the collision-affected portion of the vehicle body and transmits the collision load from the collision object to the vehicle structure.
An elastic body provided by forming a space between the collision load receiving member and the vehicle structure and having a deformable portion that can expand and contract in the direction in which the collision load receiving member receives the collision load.
It is provided with an inflator that supplies gas to the space in the stretchable body before a collision to expand the volume of the space and stretches the stretchable body.
A vehicle shock absorber that absorbs collision energy while contracting the deformed portion of the stretchable body when the collision load receiving member receives a collision load.
The deformed portion of the stretchable body is a vehicle shock absorber composed of a resin that is cured by receiving heat generated by an inflator. Oite to claim 1,
The stretchable body is divided into a fixed portion side to the vehicle structure and the collision load receiving member side, and the fixing portion side has higher strength or hardness than the collision load receiving member side. Shock absorber for vehicles.

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