JP2001163261A - Occupant crash protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an occupant crash protection device for an automobile capable of realizing a suitable reduction in occupant deceleration at collision in a simple structure together with making the car body compact in size. SOLUTION: A weight member is supported in such a manner as to move forward to some degree at collision, whereby the apparent inertial mass of the car body is minimized in the initial stage of the collision to generate a deceleration larger than the average deceleration in the whole car body including a seat, the inertial mass of the weight member is then applied to the car body with a slight delay, whereby a minus car body deceleration (acceleration) is generated, and the whole car body is finally integrally decelerated at an average deceleration, whereby not only a car body deceleration waveform suitable for the reduction in occupant deceleration can be realized, but also a significant reduction in occupant deceleration even in car body deformation (dynamic stroke) smaller than in the past can be attained. Since this can be realized in a simple structure, the car body can be made compact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant protection system for improving the collision safety of an automobile.

[0002]

2. Description of the Related Art In recent years, in order to enhance the occupant protection effect in the event of a collision of an automobile, the deformation mode in the collision of a portion other than the living space of the vehicle body is appropriately set to reduce the deceleration of the living space portion of the vehicle body. At the same time, various vehicle body structures have been proposed in which the deformation does not reach the living space (Japanese Unexamined Patent Publication No. 7-10).
No. 1354).

On the other hand, a factor that affects the degree of occupant injury at the time of a collision is generally the maximum value of the acceleration (deceleration) of the occupant. Therefore, in order to reduce the injury at the time of a collision, first, the deceleration of the occupant (at the time of a forward collision) may be reduced. Further, the deceleration of the occupant is caused by a force applied from a restraint device such as a seat belt. However, because the seat belt functions as a spring, the occupant moves forward due to inertial force, and the occupant deceleration reaches a peak when the seat belt elongates to a maximum, and the peak value of the occupant deceleration is It is said that the greater the amount of movement of the occupant due to the inertial force, the higher the value, and generally higher than the average deceleration of the vehicle body.

If the relationship between the vehicle body deceleration and the occupant deceleration is regarded as an input / output to / from a system constituted by a spring (restraint device) and a mass (occupant mass), the maximum value of the spring extension and its It can be seen that the time is governed by the vehicle body deceleration waveform (time change). Therefore, in order to reduce the occupant deceleration at the time of collision, it is necessary not only to reduce the average deceleration of the vehicle body but also to adjust the waveform of the vehicle body deceleration so that the overshoot of the spring (seat belt) becomes as small as possible. is there.

In a conventional vehicle body structure, a crushable zone formed between a collision reaction force generating member (such as a side beam) and each component is disposed at a front portion of the vehicle body.
By deforming this part, the collision energy is absorbed, and the waveform of the vehicle body deceleration is adjusted by changing the reaction force characteristics by setting the dimensions of each part.

[0006]

The waveform of the vehicle body deceleration is an important factor in reducing the occupant injury. However, the waveform of the vehicle body deceleration that can suppress the occupant deceleration to meet such a purpose is small. As shown by the solid line in FIG. 6, after a deceleration greater than the average deceleration is initially generated for a certain period of time (short time), and a deceleration in the opposite direction is continuously generated for a certain time (short time), A waveform that decelerates at an average deceleration can be considered. In such a waveform of the vehicle deceleration,
It has been confirmed by a simulation performed by the inventors of the present application that the occupant deceleration becomes smaller than when the distance required for decelerating the vehicle body (dynamic stroke) is the same constant deceleration (rectangular wave). .

In the conventional vehicle body structure, the crushable zone always deforms from a low strength portion at the start of a collision, and then a high strength portion deforms. Therefore, the waveform was small and large in the second half, so it was not sufficient to reduce the deceleration of the occupant.
In order to solve this problem, conventionally, a method of obtaining a constant reaction force by utilizing the crushing of a side beam, or a method of maintaining a stable reaction force by providing a plurality of partitions on the side beam (Japanese Patent Laid-Open No. No. 7-101354) has been proposed.

However, in these methods, even if the deceleration of the vehicle body can be approached to a constant deceleration (rectangular wave), it is extremely difficult to obtain a more effective deceleration waveform as shown in FIG. It was difficult.

In addition, in an electric vehicle, a battery box mounted in the center of the vehicle body is movably supported to reduce the weight of the vehicle body that receives the load generated by the side beam in the early stage of a collision, thereby improving the deceleration waveform of the vehicle body. (Japanese Patent Laid-Open Nos. 5-238287 and 5-2462).
No. 52, JP-A-5-246253, etc.).

However, the above structure is limited to an electric vehicle having a battery box mounted in the center of the vehicle body, and the battery has a small mass with respect to the entire vehicle body, so that the effect of improving the deceleration waveform is limited. There's a problem.

In order to make the deceleration of the occupant smaller than that of the conventional one, it is required to generate a vehicle body deceleration waveform as shown in FIG.

The present invention has been devised based on such knowledge, and an object of the present invention is to realize a suitable reduction of an occupant deceleration at the time of a collision with a simple structure together with a reduction in the size of a vehicle body. It is an object of the present invention to provide an occupant protection device for an automobile.

[0013]

In order to achieve the above object, according to the present invention, occupant restraining means (seat belt 9) for restraining a seated occupant to an occupant seat 8 provided on a vehicle body is provided. An impact absorbing portion (side beam 3) capable of absorbing collision energy generated in the vehicle body at a certain deceleration at the time of collision of the vehicle body, and supported by a rear portion of the vehicle body so as to be movable forward relative to the vehicle body. A weight member (engine 11), and a load transmitting member (rear bulkhead 10) for transmitting a forward load of the weight member (engine 11, battery 21) to the movable portion 2 when the weight member (engine 11) moves forward by a predetermined amount. After the weight member (the engine 11) moves forward by a predetermined amount relative to the vehicle body at the time of collision of the vehicle body to temporarily give a high deceleration to the vehicle body and the occupant seat 8, the load transmission unit (Rear bulkhead 10) transmits the forward load of the weight member to the movable part 2 to temporarily apply forward acceleration to the vehicle body and the occupant seat 8, and then increases the deceleration again to change the shock absorbing part (side beam 3). ) To absorb the collision energy.

According to this, at the time of collision, the deceleration greater than the average deceleration is generated for a fixed time (short time) by moving the weight member forward independently of the vehicle body, and thereafter the forward load of the weight member is reduced. , A deceleration (acceleration) in the opposite direction is generated for a fixed time (short time), and thereafter, an average deceleration is reached. As a result, a waveform as shown in FIG. A rapid increase in speed can be suppressed.

Further, a shock absorbing structure (hollow structure of the rear bulkhead 10) is further provided between the vehicle body and the weight member (engine 11), so that a sudden acceleration in the forward direction can be prevented.

The weight member includes an engine, a transmission, various motors, a battery, various structures, and the like.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to specific examples shown in the accompanying drawings. FIG. 1 is a perspective view showing a main part of a vehicle body structure of an automobile according to a first embodiment to which the present invention is applied. In the figure, an occupant seat 8 is provided on a main frame 1 integral with a vehicle body. The main frame 1 is integrally fixed to the upper surface of a side beam 3 extending from the front part of the vehicle body to the rear part of the vehicle body on the left and right sides of the vehicle body as a collision energy absorbing part, and has a floor portion 1a of a vehicle compartment 4; At the boundary between the cabin 4 and the bonnet room 5, there is a portion 1b that rises from the floor and reaches the front edge of the windshield.

The seat 8 is provided with a seat belt 9 constituting occupant restraining means. The shoulder-side anchor point 9a of the seat belt 9 is provided at the upper end of the seat back 8a, but may be attached to the vehicle body. In this configuration, the occupant restraining means is a seat belt. However, the present invention is not limited to the seat belt. good.

A support structure including a rail and a slider is provided between the seat 8 and the floor of the main frame 1 so that the seat 8 can move in the front-rear direction.

An engine 11 as a heavy member is supported by a side beam 3 in an engine room 6 defined by a rear bulkhead 10 at the rear of the vehicle body. here,
At the front part of the side beam 3 supporting the engine 11, stress concentrates on that part when a forward load occurs at the time of collision,
A bent portion 3a is provided, which bends and deforms so that the engine 11 can easily move forward relative to the vehicle body.
The deformation load of the bent portion 3a is set so as not to cause any trouble during normal running, and to start deformation by receiving the collision load when a frontal collision occurs, so that the engine 11 quickly moves forward. Actually, a constricted portion may be formed so as to be easily buckled, or the whole or a part of the support structure (engine mount) may be slidable with respect to the side beam 3.

The rear bulkhead 10 provided in front of the engine 11 is hollow, and functions as a load transmitting member having a buffer structure for transmitting the shock load to the vehicle body while buffering the impact load at the time of impact of the engine 11 described later. The engine 11 and the rear bulkhead 10 are separated by a predetermined gap L.

The state of the thus constructed vehicle at the time of a collision will be described below with reference to FIGS.

FIG. 2 is a side view similar to FIG. 1, showing an initial state of the collision. For example, when the vehicle collides with the obstacle W, the front panel portion of the body outer panel is crushed, and the end of the side beam 3 that projects forward from the vehicle body immediately hits the obstacle W. The side beam 3 starts to be crushed and generates a predetermined deceleration, but the bent portion 3a of the side beam 3 is deformed by the inertial force of the engine 11 as a heavy member, and the engine 11
Keeps moving forward. Accordingly, the mass of the entire vehicle at this time is apparently reduced by the amount of the engine, and a deceleration larger than the average deceleration occurs for a certain time (short time). As a result, the seat belt load of the seat 8 rises earlier than before, and the deceleration of the occupant also occurs earlier.

In the first half of the middle period of the collision shown in FIG.
The engine 11 collides with the rear bulkhead 10, whereby the inertial mass of the engine 11 acts on the vehicle body mass, and a reverse deceleration, that is, a forward acceleration is generated on the vehicle body.

The state of occurrence of the deceleration in the collision traveling direction is a deceleration on the minus side shown in FIG. 6, and the deceleration in the opposite direction causes the vehicle body while receiving the tension of the seat belt 9 while receiving the tension of the seat belt 9. Stop relative forward movement. FIG.
The vehicle deceleration is at the shoulder anchor point 9 as described above.
a.

At this point, when the generation of the deceleration on the negative side of the seat 8 ends, the characteristics of the seat belt 9 and the engine 11 are adjusted so that the occupant's speed and deceleration match the speed and deceleration of the seat 8. It is desirable to appropriately design the gap L with the rear bulkhead 10.

In the latter half of the middle stage of the collision shown in FIG.
As the rear bulkhead 10 is crushed by the collision of the engine 11 with the rear bulkhead 10, the impact load is transmitted to the vehicle body while buffering the impact load at the time of the collision of the engine 11. Therefore, the shock absorption gradually increases, and the deceleration of the vehicle body gradually increases again until the forward movement of the engine 11 with respect to the vehicle body stops.

Here, when the forward movement of the engine 11 with respect to the vehicle body is stopped, the speed and deceleration of the
If the speed and the deceleration of the seat 1 coincide with the deceleration, the occupant does not move relative to the seat 8 and continues to decelerate integrally. That is, the ride down effect can be used to the maximum.

In the late stage of the collision shown in FIG. 5, the engine 11 is substantially integral with the vehicle body, the side beams 3 are crushed, and the occupant rides down on the vehicle body, until the collision is completed. The deceleration becomes substantially equal to the occupant deceleration (see FIG. 6). At this time, since the collision load is applied to the mass of the entire vehicle body including the engine 11, the vehicle body deceleration becomes smaller than that immediately after the start of the collision.

In this way, the vehicle body is deformed at the time of a collision, and a suitable change in the deceleration of the vehicle body and the occupant can be generated as shown in the graph of FIG. Further, even if the speed difference between the engine 11 and the vehicle body cannot be sufficiently secured, and the portion where the vehicle body deceleration in FIG. Can be improved for other vehicles.

[0031]

As described above, according to the present invention, by supporting the weight member so as to be movable to a certain extent forward in the event of a collision, the apparent inertial mass of the vehicle body can be reduced in the early stage of the collision to include the seat. A deceleration greater than the average deceleration is generated in the entire vehicle body, and then the inertia mass of the above-mentioned weight member is added slightly later with respect to the vehicle body to generate a negative vehicle deceleration (acceleration). As a unit, the vehicle decelerates at an average deceleration, so that not only a vehicle deceleration waveform suitable for reducing occupant deceleration can be realized, but also a vehicle body deformation amount (dynamic stroke) smaller than before.
Also, a significant reduction in the occupant deceleration can be achieved. Further, since the vehicle body can be realized with a simple structure, the vehicle body can be made compact.

Furthermore, the amount of movement of the occupant in the vehicle (displacement with respect to the vehicle body) can be suppressed to be smaller than when the occupant deceleration is reduced by using, for example, a load limiter in the restraint device.
There is also an effect that the possibility of a secondary collision can be reduced.

By providing a buffer structure between the vehicle body and the weight member, it is possible to prevent a sudden increase in deceleration after a forward acceleration is generated.

[Brief description of the drawings]

FIG. 1 is a side view showing a main part of a vehicle body structure of an automobile to which the present invention is applied.

FIG. 2 is a view corresponding to FIG. 1 and showing a state of an initial collision.

FIG. 3 is a view corresponding to FIG. 1, showing a state in the first half of the middle stage of the collision.

FIG. 4 is a view corresponding to FIG. 1, showing a state in the latter half of the middle stage of the collision.

FIG. 5 is a view corresponding to FIG. 1, showing a state in a late stage of the collision.

FIG. 6 is a diagram showing desirable waveforms of vehicle body deceleration and occupant deceleration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main frame 3 Side beam (shock absorbing part) 8 Seat 9 Seat belt 10 Rear bulkhead 11 Engine

Claims (2)

[Claims] An occupant restraining means for restraining a seated occupant to an occupant seat provided on the vehicle body; A weight member supported at a rear portion of the vehicle body so as to be movable forward relative to the vehicle body; and a load transmitting member transmitting a forward load of the weight member to the vehicle body when the weight member moves forward by a predetermined amount. The load transmitting member is provided after the weight member moves forward by a predetermined amount relative to the vehicle body at the time of collision of the vehicle body to temporarily provide a high deceleration to the vehicle body and the occupant seat. As a result, the forward load of the weight member is transmitted to the vehicle body to temporarily apply forward acceleration to the vehicle body and the occupant seat, and then increase the deceleration again to absorb the collision energy in the shock absorbing portion. What And the occupant protection device of a motor vehicle, characterized in that are. 2. The occupant protection device according to claim 1, further comprising a buffer structure between the vehicle body and the weight member.