JPH0948317A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag device capable of changing the capacity of a bag body in the tensile stated. SOLUTION: An upper ground fabric 18 and a lower ground fabric 20 are sewn by a sewing thread 22C to form a bag body 10. The bag body 10 is partitioned into a main chamber formation section 26A having a prescribed capacity, the first auxiliary chamber formation sections 26B arranged on its outsides, and the second auxiliary chamber formation sections 26C arranged on their outsides. The capacity of the bag body 10 can be changed when sewing threads 22B, 22C are cut, and the single bag body 10 is set to various inflated states in response to various inflow gas quantities.

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 for inflating a bag toward an occupant when the vehicle is suddenly decelerated.

[0002]

2. Description of the Related Art In an air bag device, for example, an air bag device mounted on a steering wheel, its base plate is fixed to a hub of the steering wheel by a fixing bolt or the like. A bag body is folded and accommodated in the pad cover of the airbag device. At the time of sudden vehicle deceleration such as a vehicle collision, the bag body expands into a flat spherical shape and is interposed between the steering wheel and the occupant to absorb the kinetic energy of the occupant.

[0003]

By the way, the bag body used in such an air bag device is formed so as to correspond to an inflator having a predetermined volume of gas generating agent. However, the gas volume of the inflator is variable. For example, a variable inflator capable of ejecting 40 liters and 60 liters separately or together is conceivable.
This variable inflator is intended to use the same inflator for different vehicle types and to change the expansion capacity according to the running condition of the vehicle. Therefore, it is desired to manufacture a bag body corresponding to the variable inflator. Further, in the bag which does not correspond to the variable inflator, when the generated gas has a maximum capacity or less, the bag is not maintained in a predetermined shape.

In view of the above facts, the present invention is to provide an airbag device capable of changing the capacity of the bag body while maintaining the bag body in a predetermined shape.

[0005]

An airbag device according to a first aspect of the present invention communicates with gas generating means, a main chamber forming portion capable of accommodating a predetermined volume of pressure gas, and the main chamber forming portion. An accommodating portion partitioned into the formed sub-chamber forming portion,
In order to change the storage capacity of the storage portion and to maintain the storage portion in a tensioned state, the main chamber forming portion and the sub chamber forming portion are continuously sewn together by stitching the main chamber. It is characterized in that it has a bag body provided with variable holding means for releasing the sewing and breaking when the pressure in the forming portion reaches a predetermined value.

According to a second aspect of the present invention, in the airbag device, the gas generating means, the accommodating portion capable of accommodating a predetermined volume of pressure gas, the accommodating capacity of the accommodating portion are changed,
In order to hold the accommodating part in a predetermined shape, the bag body is provided with a strap that is disposed in the accommodating part and that breaks when the pressure in the accommodating part reaches a predetermined value.

According to a third aspect of the present invention, in an airbag device, a gas generating means, a storage portion capable of storing a predetermined volume of pressure gas, and a storage capacity of the storage portion are changed.
In order to hold the accommodation portion in a tensioned state, an elastic body for tensioning the bag body by an elastic force is included, and a bag body is provided.

An airbag device according to a fourth aspect of the present invention is characterized in that the elastic body is formed integrally with the accommodating portion.

An airbag device according to a fifth aspect of the present invention is characterized in that the elastic body covers the accommodating portion.

According to the bag body of the present invention, when the vehicle suddenly decelerates, the bag body is inflated by the gas from the gas generating means and intervenes between the bag body and the occupant to absorb the kinetic energy of the occupant. .

According to the bag body of the first aspect of the present invention, the accommodation capacity of the accommodating portion is changed by the variable holding means and the accommodation portion is tensioned so as to correspond to the gas generating means. Retained.

According to the second aspect of the present invention, the accommodation capacity of the accommodation portion is changed by the strap and the accommodation portion is held in a predetermined shape so as to correspond to the gas generating means.

According to the third aspect of the present invention, the elastic body changes the accommodation capacity of the accommodating portion so as to correspond to the gas generating means, and the accommodating portion is held in a tensioned state. To be done.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIGS. 1 to 3 show a schematic overall configuration of an airbag device 12 to which a bag body 10 according to a first embodiment of the present invention is applied in a bag body inflated state.

The airbag device 12 is arranged in a folded state at a central portion of a steering wheel (not shown), and is rotatable or relatively rotatable with the steering wheel. In this airbag device 12, the bag body 10 is folded and accommodated inside a box-shaped case (not shown). The bag body 10 is connected to an inflator 16 as a gas generating means through a mounting hole 24 formed in a central portion of the lower base cloth 20. The inflator 16 can eject 40 liters of gas and 60 liters of gas separately or together. That is, when the inflator 16 ejects only 40 liters of gas, when it injects only 60 liters of gas,
Select the case of ejecting liter of gas first and then ejecting 60 liter, the case of ejecting 60 liter of gas first and then ejecting 40 liter, and the case of ejecting 40 liter and 60 liter of gas at the same time. it can.

A gas generating substance is enclosed in the inflator 16, and when the vehicle is rapidly decelerated, the gas generating substance is decomposed by combustion by the acceleration sensor to release a large amount of gas, and the bag body 10 can be inflated by this gas. It is not limited to the method of burning the gas generating substance, and the pressure gas may be stored in a cylinder or the like in advance and the pressure gas may be guided into the bag body 10 at the time of sudden deceleration of the vehicle.

The bag body 10 is formed so that it can be inflated into a substantially spherical bag shape by sewing an upper base cloth 18 and a lower base cloth 20. That is, the bag body 10 is sewn by the suture thread 22A in a state where the outer peripheral edge portions of the upper base cloth 18 and the lower base cloth 20 which are cut into a circular shape are folded back inwardly and aligned with each other. The suture thread 22A is 1260 as an example.
It is considered as a denier thread.

The upper base cloth 18 and the lower base cloth 20 are sewn to each other concentrically with the suture thread 22A with suture threads 22B and 22C. As shown in FIG. 1, the inside of the suture thread 22C is the main chamber forming portion 2.
6A, the first sub forming portion 26B is between the suture thread 22B and the suture thread 22C, and the second sub forming portion 26C is between the suture thread 22A and the suture thread 22B.

The suture strength of the sutures 22B and 22C is lower than the suture strength of the suture 22A, and the suture 22C is supplied with gas of 40 liters or more into the main chamber forming portion 26A so that the pressure is increased. When it reaches a predetermined value, it is cut off. The suture thread 22B is the sub chamber forming portion 26A.
When 60 liters or more of gas is supplied to and 26B and the pressure in the first sub chamber forming portion 26B reaches a predetermined value, the gas is cut off. For this purpose, sutures 22B and 22C having a lower tensile strength than the suture 22A are used, and the suture 22A is sewn by sewing the upper base fabric 18 and the lower base fabric 20 a plurality of times, whereas The yarns 22B and 22C can be applied with a strength differentiating means such as stitching less than this number of times, for example, only one turn.

Until such sutures 22B and 22C are cut, the sutures 22B and 22C sufficiently secure the sealing property at the sutured portion. Therefore, the gas flowing into the main chamber forming portion 26A does not leak into the first and second sub chamber forming portions 26B and 26C during the process of inflating the bag body 10.

That is, as shown in FIG.
Due to the stitching of C, the bag body 10 has a main chamber forming portion 26A as a housing portion having a capacity of 40 liters, a first sub chamber forming portion 26B as a housing portion arranged on the outside thereof, and a outside thereof. Second sub-chamber forming portion 2 as a storage portion to be arranged
It is divided into 6C. As shown in FIG. 1, the bag body 10 thus partitioned into the main chamber forming portion 26A and the sub chamber forming portions 26B and 26C is such that the gas from the inflator 16 is initially contained only in the main chamber forming portion 26A. It is flowed in and it expands.

On the other hand, as shown in FIG. 2, when the total amount of the gas ejected from the inflator 16 exceeds 60 liters, the suture thread 22C is broken and the gas in the main chamber forming portion 26A becomes the first sub chamber forming portion. It flows into 26B and expands it. In this state, the main chamber forming portion 26A and the first sub chamber forming portion 26B form a single continuous space. Further, as shown in FIG. 3, when the total amount of gas ejected from the inflator 16 exceeds 60 liters, the suture thread 22B is broken and the gas in the main chamber forming portion 26A and the first sub chamber forming portion 26B is discharged. When the total amount of gas ejected from the inflator 16 reaches about 100 liters and flows into the second sub chamber forming portion 26C, the entire bag body 10 is in an inflated state.

The strengths of the sutures 22B and 22C are not limited to those in the present embodiment, and can be appropriately changed as long as the strength is such that the sutures 22B and 22C can be broken by the increase of the internal pressure of the bag body 10 and the sewing can be released. Further, in the above-described embodiment, various threads such as natural fibers or synthetic fibers can be applied to the sewing thread used for sewing.

Next, the operation of the first embodiment will be described. When the airbag device 12 is not operated, the bag body 10 is stored in the steering wheel. When the vehicle suddenly decelerates, the airbag device 12 inflates the bag body 10 due to the generation of gas from the inflator 16 and intervenes between the steering wheel and the occupant to absorb the kinetic energy of the occupant.

When the inflator 16 is set in advance to generate 40 liters of gas, the main chamber forming portion 26A of the bag body 10 is inflated by the gas of 40 liters capacity generated from the inflator 16. The internal pressure of the main chamber forming portion 26A reaches a value required in the initial stage of expansion. That is, as shown in FIG. 1, the suture thread 22C does not break.

If the inflator 16 is preset to generate a gas of a volume of 60 liters,
First, when the amount of gas flowing in reaches 40 liters, the main chamber forming portion 26A expands, and when the remaining 20 liters of gas flow in, the internal pressure in the main chamber forming portion 26A rises.
Therefore, as shown in FIG. 2, the suture thread 22C receives a force that separates the sutured portions of the upper base cloth 18 and the lower base cloth 20 from the suture thread 22C, and the suture thread 22C is pulled by the force and is broken. The sewn portions of the upper base cloth 18 and the lower base cloth 20 superposed by the suture thread 22C are separated from each other, and the main chamber forming portion 26A and the first sub chamber forming portion 26 are formed.
As a result, the gas in the main chamber forming portion 26A flows into the first sub chamber forming portion 26B. Therefore, the first sub chamber forming portion 26B also expands and the capacity of the entire bag body 10 increases.

When the inflator 16 is set to generate a gas of a volume of 100 liters, the suture thread 22C is expanded after the main chamber forming portion 26A is inflated as described in the case of 60 liters. Is broken and the main chamber forming portion 26A and the first sub chamber forming portion 26B are brought into communication with each other. Since gas is further generated from the inflator 16, as shown in FIG. 3, the suture thread 22B is subjected to a pulling force so that the suture thread 22B is ruptured due to a force separating the suture thread 22B. As a result, the sewn portions of the upper base cloth 18 and the lower base cloth 20, which are superposed by the suture thread 22B, are separated from each other, and the inside and outside of the second sub chamber forming portion 26C are brought into communication with each other.

According to this embodiment, the sutures 22B, 22
Since C can be cut off and the capacity of the bag body 10 can be changed, the single bag body 10 can be inflated in accordance with various inflow gas amounts. Therefore, according to the present embodiment, since the single bag body 10 can be shared, compared with the case where each bag body is manufactured corresponding to each gas volume,
Cost reduction.

In the above description, the amount of gas generated by the inflator 16 is preset, for example, for each vehicle type. However, even if the same inflator 16 is used, the amount of gas generated may differ due to the difference in acceleration during operation. Even if the volume is set to change (40 liters, 60 liters or 100 liters), the sutures 22C, 22
Due to the fracture of B, the expanded state can be always maintained regardless of the amount of generated gas. This point is the same in the following embodiments.

Also, in this embodiment, the upper base cloth 1
8. Since the lower base cloth 20 is sewn with the sutures 22B and 22C, it is easy to calculate the strength of the thread according to the kind of the thread, and it becomes easy to select the thread corresponding to the predetermined gas pressure and the like. The number of parts can be reduced as compared with the case where another member is used as the variable holding means.

(Second Embodiment) FIGS. 4 to 6 show a second embodiment of the present invention. Similar to the first embodiment, this embodiment is also an example in which the present invention is applied to the steering of the vehicle.

The bag body 1 of the airbag device 12 of this embodiment.
In 0, the bag body 10 is not partitioned by the sewing thread as in the first embodiment, and the base cloth 20 thereof has the elastic net 27 as an elastic body formed of rubber elastomer or the like.
The elastic net 27 provides tension when gas is introduced into the bag body 10. That is, the elastic net 27 expands when the pressure inside the bag 10 is increased by the gas. In this embodiment, the elastic cloth 27 is attached to the base cloth 20.
In addition to weaving, the base fabric 20 itself may be formed of elastic yarn or the like.

In this embodiment, as shown in FIG. 4, when a gas of 40 liters generated from the inflator 16 flows into the bag body 10, the bag body 10 is stretched by the elastic force of the elastic net 27. It expands to a predetermined size while holding. Also, 60 liters of gas is used for the bag 10.
The elastic net 27 expands elastically and expands to a predetermined size with tension (see FIG. 5),
When 100 liters of gas is introduced into the bag body 10, the elastic net 27 is further expanded by elastic force and expanded to a predetermined size with tension (see FIG. 6). Note that 100
In the case of liter, the elastic net 27 is in a state of being stretched to the maximum.

According to this embodiment, the inflator 16 corresponds to 40 liters and 60 liters, respectively.
Even when 0 is inflated, since the bag body 10 can be maintained in a state of having a constant tension by the elastic force of the elastic net 27, the bag body 10 can be sufficiently tensioned, The airbag device 1 that can absorb the impact on the occupant
It is possible to fully exert the function of 2. In the present embodiment, since the elastic net 27 is simply woven into the lower base cloth 20, the bag body 10 can be easily manufactured. Note that the other configurations and effects are similar to those of the first embodiment. Further, in this embodiment, the elastic net 27 may be applied to the upper base cloth 18.

(Third Embodiment) FIGS. 7 to 9 show a third embodiment of the present invention. Similar to the first embodiment, this embodiment is also an example in which the present invention is applied to the steering of the vehicle.

The bag body 1 of the airbag device 12 of this embodiment.
Inside the 0 (upper base fabric 18 and lower base fabric 20), a pair of elongate first straps 30 and a pair of second straps 32 are arranged. The straps 30, 32 are located on both the left and right sides of the mounting hole 24, and the straps 30, 3 are
2 are located on the lower side of the mounting hole 24, and the upper end is sewn and connected to the upper base cloth 18 and the lower end is sewn and connected to the lower base cloth 20, respectively. These straps 30, 32 limit the expansion and deployment amount of the upper base cloth 18 and the lower base cloth 20 when the bag body 10 is expanded, so that the bag body 10 maintains a predetermined shape. . Notches 31 and 33 are formed in the straps 30 and 32 as cutting means so that the straps 30 and 32 are easily cut. Even if the notches 31 and 33 are not formed,
Any cutting means may be used as long as it is cut at a constant pressure.

The notch 31 of the first strap 30 is for 40 liters, and is not cut when 40 liters of gas flows into the bag body 10 (see FIG. 7), and 60 liters of gas flows in. It is formed so as to be cut when it is cut (see FIG. 8). The notch 33 of the second strap 32 is for 60 liters, and is provided on the bag body 60 by 60.
It is not cut when liter of gas is introduced, 10
It is formed so as to be cut off when 0 liter is introduced. Therefore, as shown in FIG.
When 100 liters of gas is introduced into the first and second straps 30, 32, the first and second straps 30 and 32 are cut and expanded to the maximum extent.

In this embodiment, the inflator 16 is used.
40 liters and 60 liters of gas are jetted from each to inflate the bag body 10 and the strap 3
The bag body 10 can be sufficiently tensioned by 0 and 32, and the function of the airbag device 12 can be sufficiently exerted. Other configurations, functions and effects are similar to those of the first embodiment.

Not limited to the case where the straps 30 and 32 are broken, an elastically elongate material such as a rubber cord or a plastically elongate material such as a vinyl cord may be used.

(Fourth Embodiment) FIGS. 10 to 13 show a fourth embodiment of the present invention. Similar to the first embodiment, this embodiment is also an example in which the present invention is applied to the steering of the vehicle.

The airbag device according to the present embodiment has a bag body 10.
In this example, the outside of the is covered with a net 34 that is an elastic body. The net 34 is formed in a bag shape, and the base portion 34A of the net 34 is overlapped and sewn at the peripheral portion of the attachment hole 24 of the bag body 10. The net 34 is made of, for example, rubber elastomer.

The net 34 is 40 liters in the bag body 10,
When 60 liters of gas are respectively introduced, the bag 10 is stretched and the bag 10 is given tension. In the present embodiment, the elastic body is an example of a net, but the elastic body is not limited to this, and a cloth or the like can be similarly applied as long as it has elasticity.

In this embodiment, the inflator 16 is used.
Even when 40 liters and 60 liters of gas are jetted from each to inflate the bag body 10, the bag body 10 can be sufficiently tensioned by the elastic force of the net 34.

FIG. 13 shows changes in internal pressure when the bag body 10 according to this embodiment is inflated. Line A shows a state in which the ignition means of the 40 liter portion is ignited, and line B shows 60.
The state in which the ignition means of the liter portion is ignited is shown.

Lines C and D show the state in which 100 liters flow into the bag body 10, and line C shows the state in which the ignition means of the 40 liter portion and the 60 liter portion are simultaneously ignited. Line D is obtained by shifting the ignition times of the ignition means of the 40 liter part and the 60 liter part, for example, after igniting the ignition means of the 60 liter part and then igniting the ignition means of the 40 liter part several seconds later. is there.

As shown by lines C and D in FIG. 13, when the ignition time is shifted as compared with the case where the ignition means of the 40-liter portion and the ignition means of the 60-liter portion are simultaneously ignited, it is better to shift the ignition time. In the initial stage of expansion, the time T until reaching a predetermined pressure becomes long and the pressure curve becomes gentle. That is, the absorption timing or the like for absorbing the kinetic energy of the occupant can be selectively used according to the vehicle speed, the occupant position, and the like. Note that the other configurations and effects are similar to those of the first embodiment.

The type of the airbag sensor according to the present invention may be mechanical type or electrical type. Further, although the airbag device 12 of the present invention is arranged on the steering of the vehicle, the airbag device may be arranged between the outer panel and the inner panel of the door and inflated to the side of the occupant. The same can be applied to other airbag devices.

[0048]

As described above, the airbag device according to the present invention can change the capacity of the bag body while maintaining the bag body in a predetermined shape.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a bag body of an airbag device according to a first embodiment of the present invention in an inflated state.

FIG. 2 is a cross-sectional view showing a configuration of a bag body of the airbag device according to the first embodiment of the present invention in an inflated state.

FIG. 3 is a sectional view in an inflated state showing a configuration of a bag body of the airbag device according to the first embodiment of the present invention.

FIG. 4 is a partially cutaway side view in an inflated state showing a configuration of a bag body of an airbag device according to a second embodiment of the present invention.

FIG. 5 is a partially cutaway side view in an inflated state showing a configuration of a bag body of an airbag device according to a second embodiment of the present invention.

FIG. 6 is a partially cutaway side view in an inflated state showing a configuration of a bag body of an airbag device according to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a configuration of a bag body of an airbag device according to a third embodiment of the present invention in an inflated state.

FIG. 8 is a sectional view in an inflated state showing a configuration of a bag body of an airbag device according to a third embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a configuration of a bag body of an airbag device according to a third embodiment of the present invention in an inflated state.

FIG. 10 is a partially cutaway perspective view showing a configuration of a bag body of an airbag device according to a fourth embodiment of the present invention in an inflated state.

FIG. 11 is a partially cutaway perspective view in an inflated state showing a configuration of a bag body of an airbag device according to a fourth embodiment of the present invention.

FIG. 12 is a partially cutaway perspective view showing the configuration of a bag body of an airbag device according to a fourth embodiment of the present invention in an inflated state.

FIG. 13 is a diagram showing a change in internal pressure when the bag body according to the fourth embodiment of the present invention is inflated.

[Explanation of symbols]

 10 Bag Body 12 Airbag Device 16 Inflator (Gas Generation Means) 22B, 22C Suture (Variable Holding Means) 26A Main Chamber Forming Section (Accommodating Section) 26B, 26C Sub Chamber Forming Section (Accommodating Section) 27 Elastic Net (Elastic Body) ) 30, 32 Strap 34 Net (elastic body)

Claims (5)

[Claims] 1. A gas generating means, a main chamber forming part capable of containing a predetermined volume of pressure gas, and an accommodating part partitioned into an auxiliary chamber forming part formed so as to communicate with the main chamber forming part, and the accommodating part. In the main chamber forming part, a continuous part of the main chamber forming part and the sub chamber forming part is sewn to each other in order to change the accommodation capacity of the part and to keep the accommodation part in tension. And a variable holding means that breaks the sewing and breaks when the pressure reaches a predetermined value. 2. A gas generating means, an accommodating part capable of accommodating a predetermined volume of pressure gas, and an accommodating part arranged to change the accommodating capacity of the accommodating part and hold the accommodating part in a predetermined shape. An airbag device, comprising: a bag body including: a strap that is broken when the pressure in the housing portion reaches a predetermined value. 3. A gas generating means, an accommodating part capable of accommodating a predetermined volume of pressure gas, and an accommodating part for changing the accommodating capacity of the accommodating part, and for holding the accommodating part in a tensioned state An airbag device, comprising: a bag body having an elastic body for tensioning the bag body by force. 4. The airbag device according to claim 3, wherein the elastic body is formed integrally with the housing portion. 5. The airbag device according to claim 3, wherein the elastic body covers the housing portion.