JP2003276554A - Airbag device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airbag device for completing inflation early with a small volume of the airbag when a build of an occupant is small, and completing the inflation early with a sufficient volume of the airbag when the build of the occupant is large. <P>SOLUTION: When a collision is detected and the build of the occupant is small, gas is blown out only from a gas generator 86A. A first tether belt 40 remains with a front panel 32 and a rear panel 32 linked each other, and the airbag 3 rapidly inflates with the small volume. When the collision is detected and the build of the occupant is large, the gas is blown out from both of the gas generators 86A, 86B, and the airbag rapidly inflates. The gas from the second gas generator 86B is jetted on a low intensity part 86 of the first tether belt 40, and the low intensity part 68 is disrupted. As a result, the front panel 32 advances until a second tether belt 42 strains, and the airbag makes a shape of completing the inflation with the large volume. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag that is deployed at the time of a vehicle collision to protect an occupant such as an automobile. Preferably, the present invention relates to an airbag device for a driver's seat, which is improved so that the airbag can be quickly expanded to the outside of the steering wheel.

[0002]

2. Description of the Related Art An air bag device for a driver seat provided on a steering wheel of an automobile is used in an emergency such as a vehicle collision.
The pressure of gas released from the inflator rapidly inflates (deploys) the airbag to protect the occupant.

In the above-described driver airbag device, it is preferable that the airbag be rapidly deployed laterally (vertically and laterally) with respect to the occupant when the inflator is activated.

FIG. 11 is a perspective view showing the unfolded state of the driver-seat airbag 10. The airbag is constructed by stitching the peripheral portions of the front panel 14 and the rear panel 12 each made of circular cloth. There is. At the center of the rear panel 12, an opening 16 for receiving the tip side of the inflator is provided. This opening 16
A small opening (insertion hole) 1 for inserting an attachment member such as a bolt for attaching the airbag 10 to the retainer is provided around the
8 are provided. The rear panel 12 is provided with a vent hole 20 for allowing gas in the airbag 10 to escape when a driver thrusts into the airbag 10.

In order to prevent the airbag 10 from expanding so as to project toward the front, the front panel 14 and the rear panel 12 have a tether belt.
, Hanging string).

The airbag 10 and the inflator are attached to a retainer, and the airbag main body is covered with a module cover to form an airbag apparatus. When the airbag 10 is deployed by the gas from the inflator, the module cover is split. When the air bag is deployed, the tether belt is taut, so that the front panel 14 is prevented from further advancing.

Japanese Unexamined Patent Publication (Kokai) No. 8-198049 discloses an airbag device in which a relatively short first tether belt and a relatively long second tether belt are provided as a tether belt, and a low strength portion is provided on the first tether belt. Is listed. In this airbag device, when the inflator is actuated, the first tether belt is first tensioned and the airbag is spread to the outside of the steering wheel. After the peripheral portion of the airbag has spread sufficiently to the outside of the steering wheel, the gas from the inflator pushes the front part of the center of the front panel away from the center of the rear panel, and the first tether belt tears. As a result, the front panel advances until the second tether belt is in a taut state, and has a final developed shape.

[0008]

SUMMARY OF THE INVENTION The present invention is an airbag device in which the tether belt is broken or the length of the tether belt is increased after the airbag starts to expand due to the operation of the inflator. An object of the present invention is to provide an airbag device in which the lever tether belt is broken or the length is increased.

[0009]

An airbag device of the present invention (claim 1) is an airbag main body having a front portion facing an occupant and a rear portion opposite to the occupant, and the front portion of the airbag main body. A first tether belt connecting the front portion and the rear portion of the airbag body, a second tether belt having a larger length than the first tether belt connecting the front portion and the rear portion of the airbag body, and the air In an airbag device having an inflator for inflating a bag and an inflator control means for actuating the inflator in response to a collision signal, when the physique of the occupant is detected and the physique detected by the detection means is larger than a predetermined physique. And a strength reducing means for lowering the strength of the first tether belt to break it when the inflator operates. .

In such an air bag device, when the inflator operates when the occupant's body is small, the first
The tether belt becomes tight (hereinafter sometimes referred to as the first stage), and the airbag quickly inflates to the side. In this case, the inflated thickness of the airbag is small, but since the occupant's physique is small, the occupant can be sufficiently received.

When the physique of the occupant is large, the front portion of the airbag moves forward until the first tether belt breaks and the second tether belt becomes taut before reaching the first stage or immediately after the first stage, and finally. Deployment shape (hereinafter,
It is sometimes called the second stage. ). In the second stage, the airbag is inflated until it becomes sufficiently thick, so that even an occupant with a large physique can fully receive it.

In the second stage, the inner volume of the airbag increases due to the breakage of the first tether belt, but the gas is sufficiently supplied into the airbag from both the first and second gas generating portions. Being supplied, the airbag can complete inflation early.

As means for lowering the strength of the first tether belt and breaking it, the gas ejected from the inflator is
What is applied to the tether belt and the strength of the first tether belt is reduced by the heat thereof (claim 2) is simple in structure and is preferable.

In this case, the inflator is provided with the first gas generating section and the second gas generating section, and the inflator control means has only the first gas generating section when the physique of the occupant is smaller than the predetermined physique. Or the second gas generating section is operated with a delay of a predetermined time after the operation of the first gas generating section, and the inflator control means controls the inflator control means when the physique of the occupant is larger than the predetermined physique. The first and second gas generating sections are operated at all or substantially the same time, and when the airbag is inflated by the gas from the first and second gas generating sections, the second gas generating section is operated from the second gas generating section. It is preferable that the gas is blown onto the first tether belt to reduce the strength of the first tether belt (claim 3).

In this airbag device, the airbag is inflated to the first stage when only the first gas generating portion is activated. When the physique of the occupant is large, the second gas generating section also operates at almost or almost the same time as the first gas generating section, and the gas from the second gas generating section is sprayed onto the first tether belt to cause the first tether belt to blow. Strength is reduced and the first tether belt breaks. As described above, in this airbag device, when the second gas generating portion is activated, the first tether belt is reliably broken by the ejected gas.

The airbag device of the present invention (claim 4) comprises:
Collision between an airbag body having a front portion facing the occupant and a rear portion opposite to the occupant, a tether belt connecting the front portion and the rear portion of the airbag body, and an inflator for inflating the airbag. In an airbag device having an inflator control means for activating the inflator according to a signal, when the physique of the occupant is detected, and the physique detected by the detection means is larger than a predetermined physique, when the inflator is activated, A length increasing means for increasing the length of the tether belt.

In such an airbag device, when the occupant's body is small, when the inflator is activated, the tether belt is in the inflated state of the first stage where the tether belt is taut with a short length, so that the airbag quickly moves to the side. Expand to. In this case, the inflated thickness of the airbag is small, but since the occupant's physique is small, the occupant can be sufficiently received.

When the size of the occupant is large, the length of the tether belt increases before reaching the first stage or immediately after the first stage, and the front portion of the airbag advances until the long tether belt becomes taut, and the second stage Will be in an expanded state. In the second stage, the airbag is inflated until it becomes sufficiently thick, so that even an occupant with a large physique can fully receive it.

Even in such an airbag device,
Although the inner volume of the airbag increases due to the increase in the length of the tether belt in the second stage, since the gas is sufficiently supplied into the airbag from both the first and second gas generating portions, the airbag is Can complete inflation very early.

In this airbag device, the tether belts are connected at their intermediate portions by a connecting means so as to shorten the length thereof, and the inflator is the first
And a second gas generating part, wherein the inflator control means operates only the first gas generating part when the physique of the occupant is smaller than a predetermined physique, or the first gas generating part. After the operation of the part, it is delayed for a predetermined time and the second
The inflator control means actuates the first and second gas generating parts at the same time or substantially at the same time when the physique of the occupant is larger than the predetermined physique. When the bag is inflated by the gas from the first and second gas generating portions, the second gas
The gas from the gas generating part is blown onto the intermediate part of the tether belt to release the connection of the connecting means by heat,
It is preferable that the length of the tether belt is increased (claim 5).

In this air bag device, when only the first gas generating portion is activated, the air bag is inflated to the first stage. When the physique of the occupant is large, the first
At the same time as or almost simultaneously with the gas generating portion of the second gas generating portion, the gas from the second gas generating portion is blown to the tether belt to reduce the bonding strength of the connecting portion of the tether belt and release the connection, The tether belt length increases. Thus, in this airbag device, the second
When the gas generating part is activated, the tether belt is uncoupled due to the heat of the ejected gas, and its length is reliably increased.

[0022]

DETAILED DESCRIPTION OF THE INVENTION Embodiments will be described below with reference to the drawings.

FIG. 1 shows an airbag 30 according to the embodiment.
FIG. The airbag 30 has a bag body 36 formed by sewing a peripheral edge of a cloth front panel 32 and a rear panel 34 with a thread 38, and a first body connecting the front panel 32 near the center and the rear panel 34 near the center. Tether belt 40 and second tether belt 4
2 and. This second tether belt 42 is the first
The length is larger than the tether belt 40.

Two reinforcing cloths 44 and 46 are sewn with a thread 48 near the center of the front panel 32. The first tether belt 40 is one piece with the reinforcing cloth 44. The second tether belt 42 is one piece with the reinforcing cloth 46. It should be noted that each one tether belt 40, 42 is made one by one with the reinforcing cloth 44, and the remaining one tether belt 40, 42 is replaced by the other reinforcing cloth 46.
You may make it one by one. Further, some or all of the tether belts may be joined to the front panel 32 by stitching.

An opening 50 for engaging an inflator is provided near the center of the rear panel 34, and annular reinforcing cloths 52, 54 are sewn to the periphery of the opening 50 with threads 55, 56. An insertion hole 58 is provided so as to penetrate the reinforcing cloths 52, 54 and the rear panel 34. The insertion holes 58 are provided around the opening 50 at equal intervals.

The rear end of the second tether belt 42 is sewn to the reinforcing cloth 52 with the thread 60.

The rear end of the first tether belt 40 is free from being joined to neither the rear panel 34 nor the front panel 32. An insertion hole 62 is provided at the rear end of the first tether belt 40.

The first tether belt 40 has a low strength portion 68 formed by providing notches 66 on both sides. Although the V-shaped notch 66 is shown in the drawing, it may be a notch having another shape such as a semicircular notch.

The two first tether belts 40, 40 face each other across the opening 50 in the diametrical direction, and the two second tether belts 42, 42 also face each other across the opening 50 in the diametrical direction. . The tether belts 40 and 42 are provided around the opening 50 at 90 ° intervals.

FIG. 2 is an exploded perspective view showing an airbag mounting structure according to the embodiment of the present invention. The airbag 30 shown in FIG. 1 is attached to a retainer 70 by a ring (pressing ring).
The state of attachment by 72 is shown. FIG. 3 is a sectional view showing a mounting structure of the rear end of the second tether belt. 4 and 5 are sectional views showing the operation of the airbag device.

In this embodiment, the pressing ring 72 is used.
Is provided with a stud bolt 74.

The retainer 70 has an inflator mounting port 7
A bolt hole 80 through which the stud bolt 74 is inserted is formed in the peripheral edge portion of 8.

The inflator 86 is provided with a flange 88 which overlaps the peripheral portion of the inflator mounting port 78, and the flange 88 is provided with a bolt hole 90 into which the stud bolt 74 is inserted. The inflator 86 is provided with a first gas generating portion 86A on the lower side and a second gas generating portion 86B on the upper side. The second gas generating portion 86B is arranged so as to face the first tether belt 40 as shown in FIG. The first gas generating portion 86A is arranged so that neither of the tether belts 40 and 42 is oriented.

The airbag 30 is arranged on the retainer 70 such that the inflator engaging opening 50 is concentric with the inflator mounting opening 78 of the retainer 70, and the pressing ring 72 is superposed from the upper side thereof. At this time, the stud bolt 74 is attached to the insertion hole 6 of the first tether belt 40.
2, 62, the insertion hole 58 of the airbag 30, the retainer 7
0 bolt holes 80 and flange 88 bolt holes 90. Then, attach the nut 92 to the stud bolt 74.
To fix the presser ring 72 to the retainer 70,
The airbag 3 is provided between the pressing ring 72 and the retainer 70.
The edge of the zero opening 50 is clamped.

After the air bag 30 and the inflator 86 are attached to the retainer 70 in this manner, the air bag 30
Is folded, the module cover 94 (FIGS. 4 and 5) is covered, and the module cover 94 is fixed to the retainer 70 to complete the airbag device. Note that the retainer 70 of FIG. 2 has a hole 96 for inserting a blind rivet for mounting the module cover 94.

Although not shown in the figure, a weight sensor as a physique sensor for detecting the physique of the seated occupant is provided in the driver's seat behind the steering wheel in which the airbag device is installed. Instead of the weight sensor, a CCD camera or the like may be used to image the occupant and the data may be analyzed to detect the physique, or another physique detection sensor may be used.

The weight sensor is connected to the inflator control circuit. Collision detecting means is also connected to the inflator control circuit.

The inflator 86 is provided with a first combustion section communicating with the first gas generating section 86A and a second combustion section communicating with the second gas generating section 86B, and each combustion section is separated by a partition wall. Has been done. Each combustor is provided with an igniter, and each igniter is configured to be supplied with an ignition current from an inflator control circuit.

In this embodiment, when the weight of the occupant is smaller than a predetermined value (for example, 50 kg), the inflator control circuit gives an ignition signal only to the igniter of the first combustion section so that the weight of the occupant is equal to or more than the predetermined value. At some time, an ignition current is supplied from the inflator control circuit to the igniters of the first and second combustion sections, respectively.

When a vehicle collision is detected when the weight of the occupant is smaller than a predetermined value, gas is ejected only from the first gas generating section 86A, and the airbag 30 is inflated by opening the module cover 94. To do. In this case, the first tether belt 40 of the airbag 30 is in a taut state, most of the gas flows laterally in the airbag 30, and the airbag 30 quickly inflates laterally.

An occupant is received and protected by the inflated airbag 30. In this case, as shown in FIG. 4, the inflation thickness of the airbag 30 is relatively small, but since the weight of the occupant is small, the operating energy of the occupant is small and the impact is sufficiently absorbed by the airbag 30 in the state of FIG. It

When a collision is detected when the size of the occupant is large, the inflator control circuit causes the first inflator 86 to operate.
And each of the igniters of the second combustion section are energized to eject gas from both of the gas generation sections 86A and 86B. As a result, the module cover 94 is torn open and the airbag 30
Begins to deploy. In the initial stage of deployment (first stage), the first tether belt 40 connects the front panel 32 and the rear panel 34 as shown in FIG. 4, and the airbag 30 rapidly deploys to the outside of the steering wheel 98.

The gas of the second gas generating portion 86B is blown to the low strength portion 86 of the first tether belt 40, and the strength of this portion is reduced. During the first stage, the gas pressure inside the airbag 30 increases, and the front panel 32 is strongly pressed forward, so that the low-strength portion 68 of the first tether belt 40 is loaded with a tensile strength of a predetermined level or more. The low-strength portion 68 breaks. As a result, the front panel 32 advances until the second tether belt 42 becomes taut, and the deployment complete state (second stage) shown in FIG. 5 is reached.

When the gas is ejected from both the gas generating portions 86A and 86B at the same time, the low strength portion 86 of the first tether belt 40 breaks before reaching the first stage. At this time, the airbag 30 can be quickly inflated to the second stage without expanding to the outside of the steering wheel 98.

As described above, in this airbag device, when the physique of the occupant is large, the first tether belt 40 is torn when the airbag is inflated and the front panel 32 is advanced to have a sufficiently large thickness. Even a large occupant can fully receive and absorb the shock.
In the second stage, the front panel 32 stops at the position where the second tether belt 42 is taut, so that it does not come too close to the driver's seat occupant. Also,
At the second stage, the inner volume of the airbag 30 increases due to the rupture of the first tether belt 40.
Since gas is sufficiently supplied into the airbag 30 from both the first and second gas generating portions 86A and 86B, the airbag 30 can complete the inflation in an early stage.

In the above embodiment, the first tether belt 4 is used.
Although the low-strength portion 68 is formed by providing the notch 66 at 0, the low-strength portion may be formed by providing the slit 40a like the tether belt 40A of FIG.

The tether belt 40 shown in FIGS. 7 and 8 is also used.
Like B and 40C, the tether belts 40B and 40C are divided in the middle, and one of the belts 40B 'and 40C' and the other of the belts 40B "and 40C" are rivets 40b made of a low heat resistant material such as a thermoplastic resin or You may connect with the thread 40c.

FIGS. 9 and 10 are explanatory views of an airbag device according to an embodiment of the present invention (claims 5 and 6), showing the same parts as those in FIGS. 1 and 3, respectively. There is.

In the airbag 30A of this embodiment,
Instead of the tether belts 40 and 42, only one type of tether belt 110 is provided. This tether belt 110
Is obtained by folding a middle portion in the longitudinal direction and stitching the folded portions with a thread 120 made of a low heat resistant material.

The gas ejected from the second gas generating portion 86B is blown onto the folded portion so that the yarn 120
Of the tether belt 110
Will increase in length. Front panel 32 and rear panel 3
The tether belt other than the tether belt 110 is not provided between the tether belt 4 and the belt 4. Two or more tether belts 110 are preferably provided.

Second gas generating portion 86 of inflator 86
B is arranged so as to point to this folded portion when the airbag 30A is inflated. The first gas generating portion 86A is arranged so as not to face the tether belt 110.

The other structure of the airbag 30A is the same as that of the airbag 30.

Also in the airbag device having the airbag 30A, the control device of the inflator 86 causes the inflator 86 to be ignited according to the physique of the occupant.

When a collision is detected when the size of the occupant is small, gas is ejected only from the first gas generating portion 86A,
The airbag 30A inflates to the first stage where the tether belt 110 is taut. In the first stage, the airbag 30A rapidly inflates laterally. When the physique of the occupant is small, no gas is ejected from the second gas generating portion 86B, so that this first stage is the final deployed shape of the airbag 30A.

When a collision is detected when the size of the occupant is large, gas is ejected from both the first and second gas generating portions 86A and 86B of the inflator 86. In this case, the airbag 30A first quickly inflates laterally during the first stage. During the first stage, the yarn 120 is reduced in strength and is torn by the heat of the gas ejected from the second gas generating portion 86B, and the length of the tether belt 110 is increased. As a result, the airbag 30A inflates to the second stage, and receives an occupant having a large physique.

When the gas is ejected from both the gas generating portions 86A and 86B at exactly the same time, the yarn 120 breaks before reaching the first stage. At this time, the airbag 30A
Can be quickly expanded to the second stage without expanding to the outside of the steering wheel 98.

Also in this embodiment, in the second stage, the inner volume of the airbag 30A increases due to the increase in the length of the tether belt 110.
The air bag 30 from both of the gas generating portions 86A and 86B of
Since gas is sufficiently supplied to A, the airbag 30A
Can complete inflation early.

In any of the above embodiments, when the physique of the occupant is small, first the gas is ejected from the first gas generating portion 86A, and then the second gas is slightly delayed (within 30 msec, for example). The gas may be ejected from the generation unit 86B.

[0059]

As described above, according to the airbag device of the present invention, when the occupant is large in size, the airbag is inflated so as to increase the thickness, and the impact applied to the occupant can be sufficiently absorbed. .

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view of an airbag according to an embodiment.

FIG. 2 is an exploded perspective view showing a structure for attaching an airbag to a retainer according to an embodiment.

FIG. 3 is a cross-sectional view of essential parts showing a structure for attaching an airbag to a retainer according to an embodiment.

FIG. 4 is a cross-sectional view showing an initial deployment state of an airbag device including an airbag according to an embodiment.

FIG. 5 is a cross-sectional view showing a latter-stage deployment state of an airbag device including the airbag according to the embodiment.

FIG. 6 is a configuration diagram showing another structural example of the first tether belt, and FIG. 6 (b) is a sectional view taken along the line BB of FIG. 6 (a).

FIG. 7 is a structural view showing another structural example of the first tether belt, and FIG. 7B is a sectional view taken along the line BB of FIG.

FIG. 8 is a structural view showing another structural example of the first tether belt, and FIG. 8B is a sectional view taken along the line BB of FIG.

FIG. 9 is a cross-sectional perspective view showing an airbag of an airbag device according to another embodiment.

10 is a longitudinal cross-sectional view of a main part of an airbag device including the airbag of FIG.

FIG. 11 is a perspective view of the airbag from the rear side.

[Explanation of symbols]

30 airbags 32 front panel 34 Rear panel 36 bag body 40 First Tether Belt 42 Second Tether Belt 62 insertion hole 66 notches 68 Low strength part 70 retainer 72 ring 74 volts 86 inflator

Claims (5)

[Claims] 1. An airbag body having a front portion facing an occupant and a rear portion opposite to the occupant, a first tether belt connecting the front portion and the rear portion of the airbag body, and the airbag. A second tether belt, which is longer than the first tether belt, connecting the front portion and the rear portion of the bag body, an inflator for inflating the airbag, and an inflator control for operating the inflator according to a collision signal. An air bag device having means for detecting the physique of the occupant, and when the physique detected by the detection means is larger than a predetermined physique, the strength of the first tether belt is reduced when the inflator is activated. An air bag device comprising: 2. The airbag apparatus according to claim 1, wherein the strength lowering means reduces the strength of the first tether belt by applying the gas ejected from the inflator to the first tether belt. 3. The inflator according to claim 2, wherein the inflator includes a first gas generating section and a second gas generating section, and the inflator control means is configured to control the first inflator when the physique of the occupant is smaller than a predetermined physique. Of the first gas generating section, or after the first gas generating section is operated, the second gas generating section is operated with a predetermined time delay, and the inflator control means has a predetermined physique of the occupant. When the air bag is larger than the physique, the first and second gas generating parts are actuated at substantially or substantially the same time, and when the airbag is inflated by the gas from the first and second gas generating parts, the second gas generating part is actuated. The gas from the gas generating part is blown onto the first tether belt to reduce the strength of the first tether belt. 4. An airbag main body having a front portion facing an occupant and a rear portion opposite to the occupant, a tether belt connecting the front portion and the rear portion of the airbag main body, and the airbag is inflated. In an airbag device having an inflator for operating and an inflator control means for activating the inflator in response to a collision signal, in the case where the physique of the occupant is detected and the physique detected by the detection means is larger than a predetermined physique, An airbag device, comprising: a length increasing means for increasing the length of the tether belt when the inflator is activated. 5. The tether belt according to claim 4, wherein intermediate portions of the tether belt are coupled by coupling means so as to shorten the length thereof, and the inflator has a first gas generating portion and a second gas generating portion. The inflator control means activates only the first gas generating section when the physique of the occupant is smaller than the predetermined physique, or delays the first gas generating section for a predetermined period of time after activating the first gas generating section. In addition to activating the second gas generating portion, the inflator control means activates the first and second gas generating portions at substantially the same time when the physique of the occupant is larger than a predetermined physique. When the airbag is inflated by the gas from the first and second gas generating portions, the gas from the second gas generating portion is blown onto the intermediate portion of the tether belt to be bonded. Coupling stage is released by heat, the air bag system, characterized in that the length of the tether belt is increased.