JP2950078B2 - Vehicle occupant restraint system - Google Patents

Abstract

PURPOSE:To secure an air bag being large in axial length at the time of fully unfolding in a limited space by shifting a setting part of this air bag as far as a specified stroke to the specified spot in a cab in the counter rider direction synchronously with the ignition signal of a control means, and installing an unfolding auxiliary means which unfolds the air bag in both the rider and counter rider directions. CONSTITUTION:In a bag unfolding auxiliary mechanism 22, an explosive 33 is ignited by an operating signal to be outputted out of a diagnostic circuit 23, and high pressure gas generated from this explosive passes through a joint part 34, pushing a piston 31. Since this piston 31 advances forward in the axial direction in a cylinder 32, a base plate 28 being coupled with this piston 31 shifts in the counter rider direction in reverse to the air bag unfolding direction. At this time, as an air bag 25 is connected to this base plate 28, such a force as in reverse to the unfolding direction of this air bag 25 will simultaneously act on even this unfolding air bag 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle occupant restraint system for improving the occupant restraint performance in the event of a vehicle collision.

[0002]

2. Description of the Related Art In recent years, an occupant restraint device (airbag device) that deploys an airbag in front of an occupant's face at the time of a vehicle collision to protect the occupant from the impact at the time of the collision has become widespread. In this device, if the axial length of the airbag (in the direction toward the occupant) is increased, the restraint stroke (energy absorption stroke) of the occupant is correspondingly increased and the restraint performance can be improved. Is mounted on a steering wheel or the like, so it was difficult to increase the size due to the restriction on the distance between the airbag and the occupant.

[0003] In order to cope with this, the present applicant increases the distance between the mounting point of the airbag and the occupant by retracting the steering column forward by a set stroke when the airbag is deployed. Has proposed a vehicle occupant restraint system that enables the use of an airbag having a large shaft length (Japanese Patent Application No. 3-64166).

An outline of the apparatus will be described with reference to FIGS. 7 and 8.

[0005] As shown in FIG. 7, this device comprises an ignition switch 1, a diagnostic circuit 2, a front switch 3,
An airbag system circuit 8 in which a battery 5 and an airbag 7 are connected in series and a column system circuit 11 in which a column switch 9 and a steering column 10 are connected in series are connected in parallel.

In this device, at the time of collision of the vehicle, the front switch 3 is actuated by the impact, and the inflator (not shown) of the airbag 7 is ignited only when the diagnostic circuit 2 determines that the impact is due to the collision. The airbag 7 is deployed.

At this time, the column switch 9 is actuated by the impact of the collision, and as shown in FIG. 8, the steering column 10 is retracted forward of the vehicle body. A sufficient space is formed between the steering column 10 and the steering column 10.

[0008] Therefore, by securing this interval, it is possible to use the airbag 7 in which the shaft length is set to be larger than the shaft length LA of the normal airbag 7 'by the retraction amount LB.
By expanding the energy absorption stroke of the airbag,
The occupant M can be softly restrained.

[0009]

By the way, as shown in FIG. 9 (a), the airbag generally extends in the axial direction (passenger direction) in an elongated manner immediately after deployment, and has a maximum axial length.
Thereafter, as shown in FIG. 9 (b), it spreads toward the outer peripheral direction, shows a behavior that the axial length decreases and reaches the fully deployed state.

For this reason, in the proposed device, the steering column is moved forward by a set stroke corresponding to the maximum shaft length before the time when the maximum shaft length is taken so that the tip of the airbag 7 does not contact the face of the occupant. I try to pull in.

However, at the time of full deployment after the maximum axial length is taken, the axial length of the bag is reduced.
As shown in FIG. 7, the space SA is opened between the bag 7 and the occupant M.

The distance SA increases as the difference between the maximum axial length of the bag and the axial length at the time of full deployment increases, and the smaller the distance SA, the larger the airbag in a limited space. Airbag with a long axial length).

However, in the device proposed above, the bag 7 expands only in the direction of the occupant by the gas pressure generated by the inflator ignition. As in the case where the steering column is not retracted, the above-mentioned interval SA is also increased, and there is a limit to the enlargement of the airbag (increase in the axial length during full deployment).

The present invention has been made to solve such a conventional problem, and an object of the present invention is to employ an airbag having a large axial length when fully deployed in a limited space. It is an object of the present invention to provide a vehicle occupant restraint device that can be used.

[0015]

In order to achieve the above object, the invention according to claim 1 has a mounting portion provided at a predetermined position in a vehicle interior, and is supported by the mounting portion and can be deployed in the direction of an occupant in the vehicle interior. Airbag, an inflator supported by the mounting portion and deploying the airbag with high-pressure gas generated by ignition, a collision sensor for detecting a vehicle collision, and an ignition signal to the inflator based on a detection signal of the collision sensor. The control means for outputting, and the mounting portion of the airbag are moved by a predetermined stroke in a direction opposite to the direction in which the occupant is in the vehicle cabin relative to the predetermined location in the vehicle cabin in synchronization with the ignition signal of the control means, Deployment assist means for assisting the deployment of the bag, wherein the movement of the airbag mounting portion by the deployment assistance means is performed until the airbag reaches the maximum axial length.

According to a second aspect of the present invention, there is provided the vehicle occupant restraint system according to the first aspect, wherein:
It is a steering wheel.

According to a third aspect of the present invention, there is provided the vehicle occupant restraint system according to the first or second aspect, wherein the deployment assisting means ignites and generates high-pressure gas by an output signal of the control means. And a piston mechanism for moving the mounting portion in the anti-occupant direction.

[0018]

In the vehicle occupant restraint system according to the first aspect, the deployment assisting means operates in synchronization with the start of deployment of the bag, and the airbag is deployed in both the occupant direction and the anti-occupant direction. Therefore,
When the bag is deployed, inertial force acts in the anti-occupant direction, and as a result, the maximum shaft length is reduced. Therefore, the difference between the shaft length and the maximum shaft length at the time of full deployment can be reduced.

In the vehicle occupant restraint system according to the second aspect, the airbag can be deployed in both the occupant direction and the anti-occupant direction at the steering wheel.

In the vehicle occupant restraint system according to the third aspect, the mounting portion of the airbag can be reliably moved in the anti-occupant direction by the piston mechanism.

[0021]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side cross section of a vehicle occupant restraint system according to this embodiment. FIG. 2 is a side sectional view of the vehicle occupant restraint device of FIG. 1 when an airbag is deployed.

This occupant restraint system includes an airbag module 21 mounted on a steering wheel 20 and a deployment assisting means for moving an attachment point of the airbag module 21 to deploy the airbag in both the occupant direction and the anti-occupant direction. A bag deployment assisting mechanism 22 serving as an airbag module 21 outputs an ignition signal to the
Operating signal (also an "ignition signal" in this embodiment)
And a diagnostic circuit 23 as control means for supplying

The diagnostic circuit 23 diagnoses whether or not an impact is caused by a collision based on a signal of a collision sensor 24 for detecting a collision of the vehicle, and outputs the ignition signal and the operation signal according to the diagnosis result.

The airbag module 21 comprises an airbag 25, an inflator 26, and a bag cover 27. The inflator 26 has a flange 26a.
Is fixed to a base plate 28 as a mounting portion supported on the steering wheel 20 at a predetermined position in the vehicle cabin so as to be movable in the front-rear direction. The terminal of the airbag 25 is fixed to the base plate 28 using a retainer ring 29. I have.

The base plate 28 is supported on a spoke portion 30 of the steering wheel 20 via an explosive-type bag deployment assisting mechanism 22.

The bag deployment assisting mechanism 22 includes a piston 31 having a rod 31a having an end 31b fixed to a base plate 28, a cylinder 32 in which the piston 31 is slidably fitted, an explosive 33, and a cylinder 32. And gunpowder 3
3 and a joint 34
Is connected to the spoke portion 30. When the explosive 33 is ignited to generate high-pressure gas, the gas flows into the pressure chamber 34a of the cylinder 32 and the piston 3
1 moves to the left in the figure.

The rod 31 a of the piston 31 is connected to the end wall 34 b of the joint 34 by the airbag module 2.
The end wall 34 of the joint 34
When the rod 31a and the end 31b abut on b, further movement of the base plate 28 is prevented, and the base plate 28 is fixed at its movement limit. Therefore, the initial position of the base plate 28 and the joint 34
Is defined as the set stroke of the bag deployment assisting mechanism 22.

In this embodiment, a bag having a longer axial length than the standard one is used as the airbag 25. The maximum displacement amount (set stroke) of the bag deployment assisting mechanism 22 is set to be 2/3 of the difference between the standard airbag and the current airbag 25 in axial length.

Further, in this device, the ignition timing of the inflator 26 of the airbag module 21 and the ignition timing of the explosive 33 of the bag deployment assisting mechanism 22 are synchronized, and the movement of the base plate 28 and the deployment of the airbag 25 are performed in the vehicle interior. The occupant direction and the occupant direction are set so as to simultaneously proceed in both directions opposite to each other. Further, the moving speed of the base plate 28 is set so that the operation of the bag deployment assisting mechanism 22 is completed just by the set stroke when the maximum axial length of the bag is generated.

Next, the operation at the time of collision will be described.

When a collision of the vehicle is detected and an ignition signal is output from the diagnostic circuit 23, in the airbag module 21, the inflator 26 is first ignited, and the gas generated therefrom causes the airbag 25 to start deploying. As shown in FIG. 2, the airbag 25 breaks through the bag cover 27 and tries to extend in the direction of the driver (rightward in the drawing), which is the direction of the occupant in the vehicle cabin, toward the maximum shaft length.

On the other hand, in the bag deployment assisting mechanism 22, the explosive 33 is ignited by the operation signal output from the diagnostic circuit 23, and the high-pressure gas generated therefrom is transferred to the joint section 3.
4, the piston 31 is pushed. Since the piston 31 advances axially forward (leftward in the figure) in the cylinder 32, the base plate 28 connected to the piston 31 moves in the direction opposite to the airbag deployment direction and in the opposite occupant direction.

At this time, since the airbag 25 is connected to the base plate 28,
In this case, forces in the direction opposite to the direction in which the airbag 25 is deployed act simultaneously. When the bag attachment point moves forward (anti-occupant direction) at the same time as ignition, the airbag 25 moves in the occupant direction and in accordance with the forward (anti-occupant direction) inertia given to the airbag 25 during the deployment process. It is deployed in both anti-occupant directions, resulting in a shorter maximum bag length.

This phenomenon will be described in detail with reference to the experimental results shown in FIG.

In this experiment, the mounting point (base plate 2
8) When the bag is deployed in both directions while moving the bag forward (anti-occupant direction) (solid line in this embodiment), and when the bag is deployed in one direction without moving the attachment point forward. (Dotted line), the axial length of each bag was measured at each time from the start of deployment.

In this experiment, the standard bag had an axial length of 3
Bag with a shaft length of 80 mm longer than 20 mm (shaft length of 400 m
Using m), the bag attachment point was moved in the opposite direction at the same time as the deployment by 80 mm, and deployed in both directions.

From the development until 10 ms, both developed with the same axial length, but after that, the comparative example in which the back was moved forward has a longer axial length, and a difference of 40 mm occurs after 15 ms. doing. As a result, although the axial length of the bag is the same at 400 mm, the maximum axial length of the bag can be reduced by about 40 mm in the case of the present embodiment in which the bag is expanded in both directions, compared to the comparative example in which the bag is expanded in only one direction. Do you get it.

Next, the behavior at the time of back deployment will be described in more detail with reference to the operation chart of FIG. 4 and the behavior diagram of FIG.

FIG. 4 shows a standard type bag having an axial length of 320.
A bag having a shaft length of 120 mm longer than that of 440 mm and a shaft length of 440 mm when fully deployed is used, and the bag attachment point is 8 mm.
The operation chart when moving forward by 0 mm is shown. FIG. 5 shows the behavior of the bag at each time in the operation chart.

The vertical axis of the operating chart in FIG. 4 shows the axial displacement of the bag and the bag attachment point, and the horizontal axis shows time. In the figure, line A indicates the position of the tip of the bag, line B indicates the position of the bag attachment point, and line C indicates the respective initial positions. Line B 'indicates the position of the attachment point of the bag of the prior application (Japanese Patent Application No. 3-64166) into which the steering column is retracted, and line A' indicates the position of the tip of the bag.

Therefore, the distance between the line C and the line B is
It represents the bag mounting point movement amount LC, and the interval between the line A and the line B represents the axial length LA of the bag. Line D indicates the limit line of the position of the occupant in the airbag,
LD is the distance from the initial position to the limit line.

Now, if the vehicle collides at time t ₀ ,
Then collision sensor 24 detects the impact, diagnostic circuit 23 determines the correctness, the air bag 25 at time t ₁ is expanded is ignited is started. At this time, simultaneously, the bag deployment assist mechanism 22 is operated to move the bag attachment point forward.

In the example of the prior application indicated by the broken line A ′ in FIG.
_The bag is deployed at ₁ and thereafter the steering column starts moving forward at time t _2, at which time t takes the maximum axial length.
Since at time t ₃ before the ₄ is set to complete construction of forward movement, in the development process of the maximum axial length it can not be expected the effect of the inertia, development itself of the airbag itself in the only occupant direction Deployment. Therefore, the difference between the maximum shaft length of the airbag and the shaft length at the time of full deployment is also large, and the shaft length at the time of full deployment can be extended only by the same 80 mm as the forward movement amount of the bag attachment point. Only 400mm long bags can be used. For this reason, as shown in FIG. 4, after the maximum shaft length is generated, the shaft length becomes 400 mm toward the fully deployed state.
To become shorter, the distance between the occupant in all expansion time t ₅ is S
A '.

[0045] In contrast, in the embodiment of the present invention shown by the solid line, the ignition and start moving the bag attachment points in the bag deploying direction opposite simultaneously, 80 mm at the time t ₄ at the maximum axial length occurs
By moving the airbag 25 forward and continuously deploying the airbag 25 in both the occupant direction and the anti-occupant direction until the airbag reaches the maximum length, the airbag 25 is fully deployed by the forward inertia effect given to the base plate 28. In spite of the airbag 25 having a shaft length of 440 mm at the time, the maximum shaft length can be suppressed to the same as the conventional example.

After reaching the maximum axial length, the movement of the bag attachment point is stopped, so that there is no longer any effect of inertia, and the energy corresponding to this is converted to the lateral development pressure, so that the bag axial length is reduced. Is never shortened. Therefore, when fully deployed, a large shaft length of 440 mm can be used as the occupant restraining stroke.

Further, as a result, the mounting point is set at 80 m.
m, even if it is pulled in forward, the bag tip will be 360 mm toward the occupant from the initial position,
SA distance between the occupant and the bag tip at time t ₅ from SA '
To and becomes very small, restraint is started at an earlier time t ₆ than the time t _7. For this reason, the initial restraint performance is significantly improved.

In this regard, in order to obtain the same initial restraint performance, the mounting point once moved to the side opposite to the front occupant is returned to the original position while measuring the bag axial length while reducing the bag axial length. However, in the case of the present embodiment, since such a complicated control mechanism is not required at all, the structure is simple and easy to realize.

Further, since the inertia in the direction opposite to the deployment direction may be given to the bag 25 itself, it is not necessary to retract the entire steering wheel including the airbag module 21 by retracting the steering column. Only the bag attachment point needs to be moved forward.

Next, another experimental example will be described.

In this experimental example, the shaft length at the time of full deployment is 400 m
The amount of movement of the bag attachment point is set to 57 mm, which is smaller than that in the above specific example, using a bag of m.

FIG. 6 shows an operation chart. In this operation chart, the vertical axis, the horizontal axis, and each line are the same as those in FIG.

In this example, it is possible to reduce the bag to the maximum axial length despite the small amount of forward movement with respect to the prior application.

Of course, the bag shaft length after the entire development is the same 40
Since it is 0 mm, the occupant restraint strokes are equivalent.
However, since the forward movement amount of the bag attachment point is as small as 57 mm, the bag comes to the occupant side by 343 mm from the initial position (the prior application is 320 mm). Therefore, the distance between the bag tip and the occupant at a time t ₅ can start restraint at time t ₆ can be reduced to SA from SA ', initial restraint performance is improved.

In this embodiment, the movement amount of the bag attachment point may be small, so that the bag deployment assisting mechanism can be further simplified.

Further, if this example is combined with a retracting device for a steering column using a collapsible stroke, only 57 mm is used as the retracting stroke, and the remaining 23 mm when the full stroke is set to 80 mm is the collapsible stroke. Will remain as.

Therefore, in the event that the collision further occurs at a stage where the bag has withdrawn sufficiently since the first collision, the collapsible stroke of the steering column remains, so that the restraint of the occupant is further ensured. Can be done. Of course, if you wear a belt,
It goes without saying that sufficient restraint can be obtained even after the bag has been deflated, but it can be better.

The vehicle occupant restraint system according to the present invention includes:
The present invention can be applied not only to a steering wheel but also to a predetermined place in a vehicle interior such as a glove box.

[0059]

As described above, according to the first aspect of the present invention, the movement of the mounting portion of the airbag in the opposite direction is performed in synchronization with the ignition signal, and the movement is performed with the maximum axial length of the airbag. By doing so, the maximum shaft length during full deployment can be increased without increasing the maximum shaft length of the airbag due to the inertia effect in the anti-occupant direction during deployment, and the time to maintain the maximum shaft length Can be lengthened.
Therefore, it is possible to adopt an airbag having a long occupant restraining stroke in a limited space, and it is possible to further reduce the reaction force when the occupant is restrained.

Further, the difference between the maximum shaft length and the shaft lengths of all the deployed shafts can be reduced, and the tip end of the bag can be set closer to the occupant. as a result,
Early occupant restraint performance is significantly improved. Moreover, it is not necessary to have a complicated mechanism for moving the position of the bag attachment point back and forth in accordance with the change in the axial length of the bag, and this can be realized with a simple configuration.

According to the second aspect of the present invention, the restraining performance of the driver can be further enhanced.

According to the third aspect of the present invention, the restraint performance can be surely enhanced by reliable two-way deployment.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a schematic configuration of a vehicle occupant restraint system according to one embodiment of the present invention.

2 is a side sectional view of the vehicle occupant restraint device of FIG. 1 when an airbag is deployed.

FIG. 3 is a characteristic diagram showing experimental results comparing changes in the bag axial length when the airbag is deployed in both directions and when the airbag is deployed in one direction.

FIG. 4 is an operation chart of the vehicle occupant restraint device of FIG. 1;

[Figure 5] is a behavior view of the bag and the bag attachment points at each time of operation chart in FIG. 4, (a) is the behavior diagram at time t _1, (b) the behavior diagram at time t _4, (c) is it is a behavior diagram in the time t _5.

FIG. 6 is an operation chart of an occupant restraint system according to another embodiment of the present invention.

FIG. 7 is a block diagram of a vehicle occupant restraint device according to a conventional example.

FIG. 8 is a behavior diagram of a conventional steering column.

[Figure 9] is a behavior view of the bag and the bag attachment point, a behavior diagram in behavior view, (b) the time t ₅ in (a) the time t _4.

[Explanation of symbols]

 Reference Signs List 20 steering wheel (predetermined location in vehicle compartment) 22 bag deployment assistance mechanism (moving means) 23 diagnostic circuit (control device) 24 collision sensor 25 airbag 26 inflator 28 base plate (mounting part) 31 piston mechanism 32 cylinder 33 explosive

Claims (3)

(57) [Claims] 1. A mounting portion provided at a predetermined position in a vehicle interior.
And air supported by the mounting portion and deployable in the direction of an occupant in the vehicle interior.
A bag, an inflator supported by the mounting portion, and deploying the airbag with high-pressure gas generated by ignition, a collision sensor for detecting a collision of the vehicle, and outputting an ignition signal to the inflator based on a detection signal of the collision sensor. A control means, and an occupant in the vehicle interior at a predetermined position in the vehicle interior in synchronization with an ignition signal of the control means .
The specified stroke in the direction opposite to the
Deployment assisting means for assisting deployment of the airbag , wherein movement of the airbag mounting portion by the deployment assisting means is reduced.
An occupant restraint system for a vehicle, characterized in that the occupant restraint is carried out until the maximum axial length of the bag is reached . 2. The vehicle occupant restraint device according to claim 1, wherein the predetermined portion in the vehicle interior is a steering wheel. 3. The vehicle occupant restraint system according to claim 1, wherein the deployment assisting means ignites in response to an output signal of the control means, and causes the mounting portion to be counter-occupied by high-pressure gas generated. An occupant restraint system for a vehicle, wherein the occupant restraint device is a piston mechanism that moves in a direction.