JPH08127303A - Air bag device - Google Patents

Abstract

PURPOSE: To spread out an air bag body rapidly without giving comparatively big force to an occupant in case the occupant is in contact with a pad cover with respect to an on-vehicle air bag device for cramping the vehicle occupant's posture by spreading out the bag body under predetermined conditions. CONSTITUTION: An inflator 14 for generating gas under predetermined conditions and a bag body 18 placed so as to cover the inflator 14 are fixed to a base plate 16. The bag body 18 is folded up appropriately and stored in a pad cover 20. A surface, which stands opposite to an occupant, of the pad cover 20 is equipped with a tear line 20a along which the cover is to be torn up when a differential pressure between inside and outside of the pad cover 20 reaches a first predetermined pressure. Side surfaces of the top and the bottom of the pad cover 20 and side surfaces of the top and the bottom of the base plate 16 are fixed to each other with resin pins 22 which is to be torn up when the differential pressure between inside and outside of the pad cover 20 reaches a second predetermined pressure higher than the first predetermined pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag device, and more particularly to an on-vehicle air bag device for restraining the posture of a vehicle occupant by expanding a bag under a predetermined condition.

[0002]

2. Description of the Related Art Conventionally, an airbag device has been known as a safety device for restraining a posture of an occupant when an acceleration or the like exceeding a predetermined value occurs in a vehicle. In this airbag apparatus, for example, as disclosed in Japanese Utility Model Laid-Open No. 2-60652, a bag body that is deployed under a predetermined condition is generally housed in a pad cover when not deployed.

In this case, in order for the bag body to expand, a part of the pad cover must be opened to release the restraint of the bag body. On the other hand, in the device described in the above publication, a tear line having a lower breaking strength than other parts is provided in a predetermined shape on the surface of the pad cover facing the occupant to achieve the above function. . According to such a configuration, when the pressure difference between the inner and outer sides of the pad cover reaches a predetermined pressure in the process of developing the bag body housed in the pad cover, the tear line provided on the pad cover is broken and the bag is broken from the broken portion. The body will be expanded. Therefore, by appropriately setting the breaking strength of the tear line, it is possible to allow the bag body to appropriately deploy while ensuring sufficient strength under normal use conditions.

[0004]

However, the conventional airbag device described above is premised on that the surface of the pad cover facing the occupant is opened when the bag body is deployed. That is, in order to break the tear line in the conventional airbag device described above, it is necessary that the pressure difference between the inside and outside of the pad cover reaches a predetermined pressure.

Therefore, when some obstacle is in contact with the surface of the pad cover facing the occupant when the bag body is deployed, the tear cover is compared with a normal state in which there is no obstacle. The internal pressure of the bag is high enough to break the line. Therefore, the conventional airbag device described above has a relatively high internal pressure of the bag body when the pad cover is expanded, for example, when the pad cover is in contact with the occupant when the bag body is deployed. In such a situation, when the bag body comes into contact with the occupant, a relatively large force may be applied.

The present invention has been made in view of the above-mentioned points, and the expansion portion provided on the surface of the pad cover facing the occupant does not expand appropriately, and the expansion portion is expanded. It is an object of the present invention to provide an airbag device that solves the above problems by providing it on a surface that does not face an occupant.

[0007]

The above object is to provide an inflator which ejects gas under a predetermined condition, and a bag body which is expanded from a folded state by introducing gas ejected from the inflator into the interior. In an airbag device having the first cover, the first cover is provided on a surface of the pad cover facing the occupant, and is expanded when the pressure difference between the inside and the outside of the pad cover reaches a first predetermined pressure, and the pad cover. And an air bag device which is provided on a surface different from the surface facing the occupant and which is expanded when the differential pressure between the inside and outside of the pad cover reaches a second predetermined pressure. To be done.

[0008]

In the present invention, the bag body is accommodated in the pad cover when not inflated, and is deployed from the first or second deploying portion of the pad cover under a predetermined condition to restrain the posture of the occupant. . In this case, the pad cover includes the first developing portion on a surface facing the occupant, and the second developing portion on a surface different from the surface facing the occupant. Therefore, when an obstacle such as an occupant approaches the pad cover, it may come into contact with the obstacle only in the first expanding portion.

By the way, the first expanding portion is expanded when the pressure difference between the inside and outside of the pad cover reaches a first predetermined pressure, and the second expanding portion develops a pressure difference between the inside and outside of the pad cover. When it reaches the second predetermined pressure, it is expanded. Therefore,
When an obstacle is in contact with the first expanding portion and the pressure difference between the inner and outer sides of the pad cover reaches the second predetermined pressure, and when the first predetermined pressure is not yet reached, Is
Prior to the first unfolding portion, the second unfolding portion expands, and the bag body unfolds from the second unfolding portion.

In this case, the bag body does not deploy directly toward the occupant, and in such a case, a relatively large force applied to the occupant when coming into contact with the bag body is appropriately suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a steering wheel 12 of a pad module 10 of an airbag device according to an embodiment of the present invention.
The front view showing the state integrated in FIG. FIG. 2 is a side sectional view of the pad module 10 of the airbag device of this embodiment. 2 corresponds to a sectional view taken along line II-II in FIG. The configuration of the pad module 10 will be described below with reference to the drawings.

The pad module 10 as shown in FIG.
The inflator 14, the base plate 16, the bag 18, and the pad cover 20 are included. Here, the inflator 14 is a device that generates a predetermined amount of gas when the operation of the airbag is determined by an operation determination device (not shown), and is fixed to the base plate 16. Bag 1
Reference numeral 8 denotes a member arranged to cover the opening of the inflator 14 so as to take in the gas emitted from the inflator 14, and is folded into a predetermined state and stored in the pad cover 20.

The pad cover 20 has a tear line 20a formed in an H shape as shown by a broken line in FIG. 1 on the surface facing the occupant. This tear line 20a
As shown in FIG. 2, it is constituted by a groove provided on the inner surface of the pad cover 20, and has a lower breaking strength than other portions. Pad cover 20 and base plate 16
The side surfaces are fixed to each other on the left and right sides and the upper and lower sides. Here, in this embodiment, the right and left side surfaces of the pad cover 20 and the base plate 16 are fixed by rivets (not shown), and the upper and lower side surfaces thereof are fixed by the resin pin 22 and the fixing bases 24a, 24b as shown in FIG. It will be done in combination with.

The rivets for fixing the left and right side faces have sufficient strength against the expanding pressure of the bag body 18, and the resin pins 22 have a pad when the internal pressure of the bag body 18 reaches a predetermined pressure. The cover 20 and the base plate 16 are provided with such strength that the upper and lower side surfaces can be unfixed.
By the way, the above-mentioned tear line 20a is provided on the pad cover 20, and when the internal pressure of the bag body 18 rises at the time of deployment and a pressure difference occurs between the inside and outside of the pad cover 20, the tear line 20a acts so as to be broken. Tension is generated.

Therefore, when gas is ejected from the inflator 14 to start the expansion of the bag body 18, and when the pressure difference between the inside and the outside of the pad cover 20 reaches the first predetermined pressure, the tear line as shown in FIG. Breakage occurs at the portion 20a, and the pad cover 20 expands. After that, the bag body 18 is further deployed from the deployment portion of the pad cover 20 toward the occupant, and a predetermined deployment operation is promptly performed.

Here, the pad cover 20 and the base plate 16 are fixed to the resin pin 22 until the internal pressure of the bag 18 reaches a second predetermined pressure which is higher than the first predetermined pressure. It has a strength that can be maintained. Therefore,
If the vicinity of the tear line 20a of the pad cover 20 expands when the inner pressure of the bag body 18 reaches the first predetermined pressure, the fixing by the resin pin 22 is not released as shown in FIG.

Therefore, in the airbag apparatus of this embodiment, when the airbag is judged to be activated and the internal pressure of the bag body 18 reaches the first predetermined pressure, the surface of the pad cover 20 facing the occupant is fixed. When no obstacle is in contact with the occupant, that is, when there is an appropriate distance between the occupant and the pad cover 20, the internal pressure of the bag body 18 is relatively low, and then the occupant is directed toward the occupant. The bag body 18 is quickly deployed.

Therefore, according to the airbag apparatus of the present embodiment, the bag body 18 is rapidly expanded to maintain the posture of the occupant when an appropriate distance is secured between the pad cover 20 and the occupant. Can be properly restrained. In this case,
Before the bag body 18 comes into contact with the occupant, the bag body 18 is largely deployed and the internal pressure thereof is lowered, so that the occupant does not feel a relatively large force when the bag body 18 comes into contact.

By the way, on the surface of the pad cover 20 having the above-mentioned structure facing the occupant, as shown in FIG.
When 0 is present, a reaction force is generated between the outer surface of the pad cover 20 and the obstacle 30, so that even if the internal pressure of the bag body 18 reaches the first predetermined pressure, the inside and outside of the pad cover 20. The differential pressure does not reach the first predetermined pressure. In this case, in order to spread the pad cover 20 along the tear line 20a, a sufficient pressure is required to break the tear line 20a against the reaction force acting between the obstacle 30 and the pad cover 20. It needs to occur within the body 18. Therefore, in such a case, if the pad cover 20 is expanded in the vicinity of the tear line 20a to expand the bag body 18, the internal pressure of the bag body 18 when the pad cover 20 is expanded becomes the first predetermined pressure. Compared with the high pressure.

The pad module 10 is arranged in the center of the steering wheel 12 as described above.
Therefore, the occupant of the vehicle may use the pad cover 2 as the obstacle 30 depending on the situation when the airbag is determined to operate.
It may be in contact with 0. In this case, the pad cover 20 near the tear line 20a
If it is configured to wait for the expansion of the pad cover 20, the internal pressure of the bag body 18 when the pad cover 20 is expanded increases as described above, and the bag body 1 is immediately expanded after the expansion of the pad cover 20.
8 comes into contact with the occupant, which may give a relatively large force to the occupant.

On the other hand, in the pad module 10 of this embodiment, the pad cover 20 and the base plate 16 are fixed by the resin pins 22 on the upper and lower side surfaces thereof, and the tear line 20a is not broken. When the internal pressure of the bag body 18 reaches the second predetermined pressure, the fixing by the resin pin 22 is released. For this reason, in this embodiment, when the airbag is judged to be operating while the occupant is in contact with the pad cover 20, the pad cover 20 expands on the upper and lower sides as shown in FIG. The body 18 is deployed vertically with respect to the occupant.

Therefore, according to the airbag apparatus of this embodiment, even if the occupant is in contact with the pad cover 20 when the airbag is judged to be activated, the pad cover 20
The internal pressure of the bag body 18 does not exceed the second predetermined pressure when the bag is expanded, and the bag body 18 is rapidly expanded. Further, in this case, the contact between the bag body 18 and the passenger is
This is performed after the bag body 18 is largely expanded vertically and its internal pressure is sufficiently reduced, and the contact does not cause the occupant to feel a relatively large force.

As described above, according to the airbag apparatus of this embodiment, the occupant may contact the pad cover 20 not only when an appropriate distance is secured between the pad cover 20 and the occupant. Even when the occupant is present, the bag body 18 can be quickly and reliably deployed with excellent responsiveness without giving a relatively large force to the occupant, and the occupant's posture can be appropriately restrained.

In the above embodiment, the tear line 20a provided on the front surface of the pad cover 20 has the upper and lower side surfaces of the pad cover 20 fixed by the resin pin 22 to the above-mentioned first developed portion. Each corresponds to the above-mentioned second developing unit. By the way, the pad module 40 described above constitutes a mechanism corresponding to the second developing portion by fixing the pad cover 20 and the base plate 16 by using the resin pin 22, but the second developing portion is used. The structure of the section is not limited to this.

Here, FIG. 5 and FIG. 6 show the pad module 4 of the embodiment in which the second developing section is realized by another structure.
A side sectional view of 0, 50 is shown. In addition, regarding the same components as the pad module 10 described above in FIG.
The same reference numerals are given and the description thereof is omitted. That is, the pad module 40 shown in FIG.
The claw 42 that holds the upper and lower side surfaces of the base plate 44
a to 42d. In this case, the pad cover 42
The fixing force between the base plate 44 and the base plate 44 is
It is determined by the size and rigidity of d, and if the holding force is set to an appropriate value corresponding to the second predetermined pressure, the same effect as the pad module 10 described above can be obtained by the configuration of the present embodiment. be able to.

Also, the pad module 50 shown in FIG.
Means that the pad cover 52 has the through holes 52a, 5
2b, and the base plate 54 penetrates through the through holes 52a and 52b to keep the base plate 54 and the pad cover 52 in a fixed state.
4b is provided. In this case, the fixing force between the pad cover 52 and the base plate 54 is determined by the size and rigidity of the claws 54a and 54b, and if the fixing force is set to an appropriate value corresponding to the second predetermined pressure, With the configuration of this embodiment, the same effect as that of the pad module 10 described above can be obtained.

When the structure shown in FIGS. 5 and 6 is adopted, the resin pin 22 and the fixing bases 24a, 24 shown in FIG. 2 are used.
It is possible to obtain an advantage that the structure such as b is unnecessary and the structure can be simplified as compared with the pad module 10.
By the way, in the above embodiment, the second predetermined pressure is set to be higher than the first predetermined pressure, but the second predetermined pressure is not necessarily caught in such a relationship, and the first predetermined pressure is the second predetermined pressure. It may be set to a high pressure as compared with.

Further, in the above-mentioned embodiment, various expanding mechanisms are provided on the side surface of the pad, but like the front surface of the pad, the tear line is provided so that the bag body can be expanded on the side surface. It may be configured.

[0029]

As described above, according to the present invention, when some obstacle comes into contact with the surface of the pad cover facing the occupant and the differential pressure between the inside and outside of the pad cover reaches the second predetermined pressure,
If the first predetermined pressure has not yet been reached, the second deploying portion expands prior to the first deploying portion, and the bag body deploys in a direction that does not directly face the occupant. Therefore, according to the airbag device of the present invention, for example, in a situation where an obstacle such as an occupant is in contact with the pad cover, the bag body can be opened without giving a relatively large force to the occupant. Can be deployed.

[Brief description of drawings]

FIG. 1 is a front view showing a configuration in which a pad module of an airbag device according to an embodiment of the present invention is incorporated in a steering wheel.

FIG. 2 is a side sectional view of a pad module of the airbag device according to the present embodiment.

FIG. 3 is a side sectional view (No. 1) showing a developed state of the pad module of the airbag device of the present embodiment.

FIG. 4 is a side cross-sectional view (No. 2) showing a developed state of the pad module of the airbag device according to the present embodiment.

FIG. 5 is a side cross-sectional view of another embodiment of the pad module of the airbag device according to the present invention.

FIG. 6 is a side sectional view of another embodiment of the pad module of the airbag device according to the present invention.

[Explanation of symbols]

 10, 40, 50 pad module 14 inflator 16, 44, 54 base plate 18 bag 20, 42, 52 pad cover 20a tear line 22 resin pin 30 obstacle 42a, 42b, 42c, 42d, 54a, 54b claw

Claims (1)

[Claims] 1. An airbag device comprising: an inflator that ejects gas under a predetermined condition; and a bag body that expands from a folded state by introducing the gas ejected from the inflator into the airbag device. The first deployment portion provided on the surface facing the occupant and expanded when the pressure difference between the inside and outside of the pad cover reaches a first predetermined pressure, and the surface of the pad cover facing the occupant An air bag device, comprising: a second deploying portion provided on different surfaces and expanded when the pressure difference between the inside and the outside of the pad cover reaches a second predetermined pressure.