JPH0730164U - Airbag device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an airbag device which can maintain a constant internal pressure of the airbag even when the displacement amount of an occupant increases and which has a simple structure. A circular opening 1a is provided in an airbag 1, and a peripheral edge of the opening 1a and a peripheral edge of a circular flat rubber 2 having a circular hole 2a in a central portion are combined to form a hole 2a. Is a vent hole. Therefore, when the internal pressure of the airbag 1 rises, the peripheral portion of the hole 2a bends and the area of the hole 2a increases, and the flow rate of the exhaust gas 3b increases. When the internal pressure decreases, the peripheral portion of the hole 2a returns to its original shape and is discharged. Since the flow rate of the gas 3b decreases, the internal pressure of the airbag 1 is kept constant.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an airbag device, and is particularly useful when applied to an airbag having a vent hole.

[0002]

[Prior art]

 FIG. 3 is an explanatory view showing an airbag device according to a conventional technique. As shown in the figure, the airbag device has an airbag 11 and an inflator 3.

Of these, the inflator 3 is a gas generator provided in the center pad 5 at the center of the steering wheel 4, and is connected to the airbag 11. That is, the inflator 3 generates gas 3a at the time of a vehicle collision and sends the gas 3a into the airbag 11. The airbag 11 is a bag-shaped member made of cloth such as nylon, and is normally folded and stored in the center pad 5. Further, the airbag 11 is provided with a vent hole 11a which is a hole for discharging the gas 4a sent from the inflator 3. In the figure, 3b is the exhaust gas at this time, and 7 is the seat.

Therefore, according to the airbag device, when the vehicle collides, the gas 3a is sent from the inflator 3 into the airbag 11, whereby the airbag 11 expands into a substantially spherical shape as shown in FIG. 6 to restrain the upper body of the body 6 and absorb the impact load of the upper body in the direction of the steering wheel 4 (hereinafter simply referred to as impact load), so that the chest and head collide with the steering wheel 4 and the windshield (not shown). To prevent dripping. Moreover, the gas 3b is discharged from the vent hole 11a in order to adjust the internal pressure of the airbag 11 so that the occupant 6 is not injured by the reaction force from the airbag 11.

[0005]

However, in the airbag device according to the related art as described above, the upper body of the occupant 6 is displaced in the direction of the steering wheel 4 and the amount of interference between the upper body and the airbag 11, that is, the upper body. As the contact area between the air bag 11 and the air bag 11 increases, the flow rate of the exhaust gas 3b increases much because the opening area of the vent hole 11a is constant, although the rate of increase in the internal pressure of the air bag 11 increases. Without doing so, it will not be able to keep up with the rise in internal pressure. For this reason, the internal pressure of the airbag 11 is greatly increased. That is, as shown in FIG. 4A, the internal pressure of the airbag 11 is greatly increased as the displacement amount of the upper half of the occupant 6 is increased.

Therefore, the reaction force applied from the airbag 11 to the occupant 6 increases greatly in proportion to the increase in the internal pressure, and the occupant 6 may be injured by the reaction force at this time.

The following invention relating to the vent hole has been previously disclosed. JP-A-52-47233, JP-A-3-139459, JP-A-3-50054, JP-A-2-216343

However, among these, the opening area is constant and has the same problems as described above. Is that the inner surface of the airbag breaks due to the increase of the internal pressure and the opening area increases, but even if the internal pressure decreases thereafter, the opening area remains large and the internal pressure drops too much, so that the impact load is sufficient. There is a risk that the occupant's chest, etc. may not be absorbed and may collide with the steering wheel. Is that the heat-shrinkable cloth shrinks depending on the temperature of the gas and the opening area increases, and the opening area does not change in response to the internal pressure of the airbag. To do. Is equipped with an exhaust valve and control means, and keeps the internal pressure of the airbag constant by controlling the operation timing of the exhaust valve according to the weight of the occupant, the speed at the time of a collision, etc., but the device is complicated and large. There is a problem that it becomes bulky.

The present invention has been made in view of the above-described conventional art, and an object of the present invention is to provide an airbag device capable of maintaining a constant internal pressure of the airbag even when the displacement amount of an occupant increases and having a simple structure. .

[0010]

[Means for Solving the Problems]

 The structure of the present invention that achieves the above object is an airbag device including an airbag that is deployed at the time of a vehicle collision and restrains the upper body of an occupant, while providing an opening at one or more locations of the airbag. It is characterized in that the peripheral portions of these openings are connected to the peripheral portions of a flat plate-shaped flexible member having a hole having a smaller area than those of the openings in the central portion.

[0011]

[Action]

 According to the present invention having the above-described structure, as the internal pressure of the airbag rises, the peripheral pressure of the hole of the flexible member bends to the outside of the airbag due to this internal pressure. As a result, the area of the hole becomes large and the flow rate of the gas discharged from this hole increases. On the other hand, when the internal pressure is reduced, the bending of the peripheral portion is returned to the original state, and as a result, the flow rate of the gas is reduced. Therefore, the internal pressure of the airbag is kept constant even if the displacement amount of the occupant toward the front of the vehicle increases.

[0012]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same parts as those in FIG. 3 are designated by the same reference numerals, and duplicated description will be omitted.

FIG. 1 is an explanatory view showing an airbag device according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing a cross section taken along the line AA of FIG. As shown in FIG. 1, the airbag device has an inflator 3 and an airbag 1.

Of these, the airbag 1 is a bag-shaped member made of a cloth such as nylon similar to the airbag 11, is connected to the inflator 3, and is normally folded and placed in the center pad 5. It is stored. Furthermore, the airbag 1 has a vent hole formed by a circular and flat rubber 2 having a circular hole 2a in the center thereof.

That is, the airbag 1 is provided with a circular opening 1a having a larger area than the hole 2a of the rubber 2, and the peripheral edge of the opening 1a and the peripheral edge of the rubber 2 are connected to each other, and the hole 2a is used as a vent hole. There is.

Therefore, according to the airbag device, when the vehicle collides and the gas 3a is sent from the inflator 3 into the airbag 1 and the internal pressure of the airbag 1 rises, as shown in FIG. When the gas 3b is discharged from the hole 1a of No. 1 and the amount of change of the occupant 6 increases thereafter, and the internal pressure of the airbag 1 rises, the internal pressure at this time causes the internal pressure of the airbag 1 as shown in FIG. The peripheral portion of the hole 1a of the rubber 1 bends to the outside of the airbag 1, and as a result, the area of the hole 2a increases and the flow rate of the gas 3b discharged from the hole 2a at this time also increases.

When the internal pressure of the airbag 1 further decreases thereafter, the bending of the peripheral portion of the hole 2a is restored, and as a result, the flow rate of the gas 3b decreases.

Thus, the internal pressure of the airbag 1 is kept constant without increasing significantly. That is, as shown in FIG. 4B, the internal pressure of the airbag 1 is kept constant even if the amount of change of the occupant 6 increases.

Therefore, the reaction force from the airbag 1 does not injure the occupant 6, and the impact load of the occupant 6 is reliably absorbed by the airbag 1.

[0020]

[Effect of device]

 According to the present invention as specifically described in connection with the above embodiments, the internal pressure is kept constant by changing the area of the hole of the flexible member according to the change of the internal pressure of the airbag. , The occupant will not be injured and the impact load will be absorbed. Moreover, the airbag device is simple and does not become bulky.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an airbag according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 and is an explanatory view showing a change of a rubber hole according to an internal pressure of an airbag.

FIG. 3 is an explanatory view showing an airbag device according to a conventional technique.

FIG. 4 is an explanatory diagram showing the relationship between the amount of change in the occupant and the internal pressure of the airbag, where (a) shows a conventional case, and (b).
Shows the case of the embodiment of the present invention.

[Explanation of symbols]

 1 Airbag 1a Opening 2 Rubber 2a Hole 3 Inflator 3a, 3b Gas 6 Crew

Claims (1)

[Scope of utility model registration request] 1. An airbag device including an airbag that is deployed at the time of a vehicle collision to restrain the upper body of an occupant, wherein an opening is provided at one or a plurality of locations of the airbag, and the periphery of these openings is provided. An airbag device characterized in that a peripheral portion of a flat plate-like flexible member having a hole having a smaller area than these openings in a central portion is coupled to the portion.