JP2000344039A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the more moderate initial expansion behavior of an air bag by allowing the improvement of diffuser feeding gas generated by an inflator to enhance an effect due to the delay output of a multi-stage output type inflator. SOLUTION: This device is equipped with an inflator having two output parts, that is, a first stage output part 32 starting its function after prescribed delay time, and a second stage output part 34, and a diffuser 24 with openings 22a and 22b partitioning the inside of a case into an air bag housing space 18 and an inflator housing space 20 so as to feed gas generated by the inflator 14 to an air bag. The diffuser 24 is formed of a first zone 36 corresponding to the first stage output part 32, and of a second zone 38 corresponding to the second stage output part 34, and the opening 22a of the first zone 36 is made smaller in area than the opening 22b of the second zone 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device, and more particularly to a diffuser structure thereof.

[0002]

2. Description of the Related Art In general, an airbag device includes a folded airbag, an inflator serving as a gas generator, a case for accommodating and fixing the airbag and the inflator, and in some cases. Is composed of a door that covers these in a design manner, and a diffuser that partitions the interior of the case into an airbag storage space and an inflator storage space, diffuses the gas generated by the inflator, and guides the gas into the airbag.

The diffuser has a substantially flat shape and is fixed to the inner surface of the case so as to partition the inside of the case up and down, or a substantially semi-cylindrical shape surrounding the side wall of the substantially cylindrical inflator. Some of them are fixed to the bottom surface, and are provided with openings of a predetermined size and number for supplying gas from the inflator to the airbag.

The inflator conventionally used generally is of a single output type having only one output portion. For example, when the inflator is operated in a fixed volume container, its time-pressure curve has a characteristic of rising to the right. And finally reaches a predetermined pressure. In addition, when operated in a container provided with a predetermined through-hole in the fixed amount container, the time-pressure curve shows a characteristic of rising to the right, and after reaching a predetermined pressure, a mountain-shaped waveform that falls to the right after reaching the predetermined pressure. Show.

In recent years, due to the gentle inflation of airbags,
As the inflator, a multi-stage output type having two output units, that is, a first-stage output unit and a second-stage output unit that outputs the first-stage output unit with a predetermined delay time has been attracting attention. The above-mentioned delay time includes the case of 0 msec, that is, the case of simultaneously outputting the first stage output unit and the second stage output unit. In the case of such simultaneous output, the same as the case of the single output type Shows pressure characteristics. On the other hand, when the first-stage output unit and the second-stage output unit are output with a delay, the time-pressure curve shows that the right-slope characteristic once becomes gentle on the way and then rises again. An S-shaped or stair-shaped curve is shown to indicate characteristics. In general, in the case of such a delayed output, the slope of rising to the right, that is, the amount of pressure rise per unit time is smaller than in the case of the simultaneous output (single output type). The bag is gently initially inflated.

According to the present invention, the effect of the delayed output of such a multi-stage output type inflator is enhanced by devising the structure of the diffuser for supplying the gas generated by the inflator to the airbag, so that the airbag can be more gentle. The purpose is to obtain the expansion behavior.

[0007]

According to a first aspect of the present invention, there is provided an airbag apparatus, comprising: an airbag, an inflator, a case for accommodating the airbag, an interior of the case, and an airbag accommodation space and an inflator accommodation space. A diffuser having an opening for supplying a gas generated by a partition and an inflator to an airbag, wherein the inflator outputs a first-stage output section and a second-stage output section with a predetermined delay time. And an output unit, wherein the diffuser is connected to a first stage near the first stage output unit.
An opening area of the first area is set smaller than an opening area of the second area.

In this airbag device, the gas output from the first stage output portion of the inflator is mainly supplied to the airbag through an opening provided in the first region of the diffuser, and is output from the second stage output portion. The gas is mainly supplied to the airbag from an opening provided in the second region of the diffuser. In this case, since the opening area of the first region is set smaller than the opening area of the second region as described above, gas generated from the first-stage output portion that first outputs is generated by the gap between the inflator and the diffuser. The gas stays while the pressure rises, and thus can be adjusted with a tendency to reduce the gas supply amount per unit time supplied to the airbag in the early stage of operation of the inflator. This makes it more effective to reduce the pressure rise per unit time at which the delayed output is intended. The second-stage output section is normally output to maintain a predetermined airbag internal pressure for a predetermined time period. However, since the opening area of the second region is large as described above, such an output is output. Can be obtained effectively.

According to a second aspect of the present invention, there is provided an airbag device, comprising: an airbag; an inflator;
A diffuser having an opening for partitioning the inside of the case into an airbag storage space and an inflator storage space and supplying gas generated by the inflator to the airbag, wherein the inflator has a predetermined delay time. A first-stage output unit and a second-stage output unit for outputting the airbag, and the airbag storage space is secured on both the occupant side and the non-occupant side with respect to the inflator, and the occupant side The inflating airbag is housed separately in both of the housing spaces, and the diffuser is
It comprises a first region near the first-stage output portion and a second region near the second-stage output portion, and in the first region, the opening area on the side opposite to the occupant is set larger than the opening area on the occupant side. Is what it is.

In this airbag device, the opening area on the side opposite to the occupant is set to be larger than the opening area on the occupant side in the first region of the diffuser for supplying gas from the first stage output portion of the inflator to the airbag. Therefore, the amount of gas directly supplied to the airbag in the early stage of the operation of the inflator can be reduced for the airbag inflating toward the occupant. This disperses the dynamic pressure of the gas stream as it is supplied directly from the inflator to the airbag, providing mildness to the inflation of the airbag.

According to a third aspect of the present invention, in the airbag apparatus according to the second aspect, an opening area of the first region in the diffuser is set smaller than an opening area of the second region. And

As a result, similarly to the airbag device according to the first aspect, the gas supply amount per unit time supplied to the airbag in the initial stage of the operation of the inflator can be adjusted with a tendency to be reduced, and the delayed output can be further increased. To be effective. Further, an output by the second-stage output unit for maintaining a predetermined airbag internal pressure for a predetermined time period can be effectively obtained.

According to a fourth aspect of the present invention, in the airbag device according to the first or third aspect, a gap formed between the inflator and the diffuser is formed between the first region side and the second region side. A partitioning means is provided.

Thus, the gas output from the first-stage output portion of the inflator is prevented from being supplied to the airbag through the opening of the second region of the diffuser, and the gas from the opening of the first region is given higher priority. Since the pressure can be supplied, the pressure rise per unit time can be more effectively reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An airbag device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of an airbag device 10 according to one embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views of the airbag device 10, and FIG. A line,
FIG. 3 shows a cross section corresponding to line BB in FIG.

The airbag device 10 is a passenger seat airbag device disposed at a position corresponding to a passenger seat on an instrument panel (not shown) of an automobile. The airbag device 12 includes an airbag 12, an inflator 14, And a diffuser 24 that partitions the inside of the case 16 into an airbag storage space 18 and an inflator storage space 20 and has an opening 22 for supplying gas generated by the inflator 14 into the airbag 12. Become.

The case 16 has a rectangular shape with a horizontal cross section and a vertical cross section with a U shape.
It is a box-shaped container that opens upward in a U-shape, and the inside of which is formed by a flat plate-shaped diffuser 24 that is disposed horizontally at substantially the center in the height direction, and the airbag storage space 18 on the upper side (case opening side). And an inflator storage space 20 on the lower side (case bottom side). Case 1
Numeral 6 is formed to be elongated in the axial direction of the inflator 14, and an insertion port 26 into which the inflator 14 is inserted is provided on a short side surface.

The mouth of the airbag 12 is fixed to the periphery of the opening of the case 16 by a bag retainer 28.
It is stored in the airbag storage space 18 in the case 16 in a state of being folded into a predetermined shape. The gas supplied from the inflator 14 causes the case 16
Inflates and deploys from the opening toward the rear of the vehicle to restrain the occupant.

The inflator 14 has a substantially cylindrical shape.
A plurality of circular gas outlets 30 are provided on the peripheral wall surface. Then, with the axial direction thereof oriented in the vehicle width direction, the inflator storage space 2 at the bottom of the case 16 from the insertion opening 26.
0 and fixed.

The inflator 14 has a first-stage output portion 32 on one side in the axial direction and an axially-side inflator 14 that operates with a predetermined delay time with respect to the start time of the operation of the first output portion 32 inside the cylindrical shape. Output type inflator provided with two output units, the first stage output unit 32 and the second stage output unit 34.
Is mainly blown out, and the output of the second output unit 34 is mainly blown out from the gas outlet 30 existing in the other side area. Specifically, in the present embodiment, the boundary 33 between the first-stage output unit 32 and the second-stage output unit 34 is set on a line that bisects the inflator 14 in the axial direction. First stage output unit 32 and second stage output unit 34
Are connected to the connector 35, respectively, and operate based on a signal from a control unit (not shown).

The diffuser 24 has a rectangular flat plate shape having a longitudinal direction corresponding to the axial direction of the inflator 14, and is fixed to the inner surface of the case 16 so as to secure a predetermined gap between the diffuser 24 and the inflator 14. .

The diffuser 24 includes an inflator 1
4, a first region 36 near the first-stage output unit 32 and a second region 38 near the second-stage output unit 34.
The opening area of the first region 36 is set smaller than the opening area of the second region 38.

The first area 36 is an area on the side of the diffuser 24 corresponding to the first-stage output section 32, that is, an area on the first-stage output section 32 side in the longitudinal direction of the diffuser 24. It is arranged so as to cover the step output unit 32. The second region 38 is a region on the side of the diffuser 24 corresponding to the second-stage output unit 34, that is, a region on the second-stage output unit 34 side in the longitudinal direction of the diffuser 24, and is a second-stage output unit of the inflator 14. 34 so as to cover them. More specifically, the first-stage output unit 32 side is a first region 36 and the second-stage output unit 34 side is a second region 38 with respect to a line AA bisecting the diffuser 24 in the longitudinal direction.

The rectangular opening 22a in the first region 36 is replaced with the rectangular opening 22b in the second region 38.
The size is set smaller than that. In this embodiment, one opening 22 is provided for each of the regions 36 and 38.
Although a and 22b are provided, a plurality of openings 22 may be provided in each of the regions 36 and 38 as shown in FIG. In this case, the size of all the openings 22 may be the same, and the number of the openings 22 may be different to provide a difference in the opening area between the two regions 36 and 38. That is, the opening area of each of the regions 36 and 38 refers to the total opening area of the openings 22 existing in each region.

Reference numeral 40 denotes a partition wall which partitions a gap formed between the inflator 14 and the diffuser 24 into a first area 36 and a second area 38, and a lower surface at the longitudinal center of the diffuser 24. Are provided to protrude toward the inflator 14. This partition wall 40
Is a cylindrical inflator 14 as shown in FIGS.
Abuts on the peripheral wall of the upper half of the inflator to reduce the left and right communication areas of the inflator storage space 20. Thus, the partition wall 40 may not partition the inflator storage space 20 completely left and right in a sealed state.

In the airbag device 10 according to the present embodiment having the above-described configuration, first, the first inflator 14
Gas is output from the step output unit 32, and the output gas is mainly supplied into the airbag 12 from the opening 22 a of the first region 36 of the diffuser 24. At this time, since the opening area of the first region 36 is small, the gas is supplied to the inflator 1.
4 and stay in the gap between the diffuser 24 while increasing the pressure. Therefore, the amount of gas supplied to the airbag 12 per unit time in the early stage of the operation of the inflator 14 is reduced, and the initial inflation of the airbag 12 can be given a gentleness. In particular, the partition wall 40 can reduce the flow of the gas output from the first-stage output portion 32 from flowing into the second region 38 from the first region 36, so that such an effect can be further enhanced. Can be.

The gas is output from the second stage output unit 34 after a predetermined delay time with respect to the output timing of the first stage output unit 32, and the outputted gas is mainly the second gas of the diffuser 24.
The air is supplied into the airbag 12 from the opening 22b of the region 38. The second-stage output unit 34 is for discarding the output of the inflator 14 or obtaining an occupant restraining force.
This signal is output to maintain a predetermined airbag internal pressure during a predetermined time period. In the diffuser 24 of the present embodiment, such an output can be obtained effectively because the opening area of the second region 38 for supplying the gas from the second stage output portion 34 to the airbag 12 is large.

As described above, according to the present embodiment, the effect of the delayed output in the multi-stage output type inflator is enhanced, and a more gentle initial inflation behavior of the airbag 12 can be obtained.

FIGS. 4 and 5 show a modified example of the diffuser 24 in the above embodiment, in which the structures of the opening 22 and the partition wall 40 are different from those of the above embodiment.

That is, in this example, the opening 22 of the diffuser 24 has a circular opening having the same diameter as the first region 3.
6 and the second region 38, respectively, and the number of the openings 22 a existing in the first region 36 is made smaller than the number of the openings 22 b existing in the second region 38. Is set smaller than the opening area of the second region 38.

Further, the partition wall 40 is provided with the diffuser 24.
Is formed by providing a bent portion that bends downward at the center in the longitudinal direction, and the downwardly projecting dimension of the partition wall 40 is constant in the short direction of the diffuser 24. In this manner, the partition wall 40 is effective even to the extent that the left and right communication areas of the inflator storage space 20 are reduced.

FIG. 6 is a sectional view of an airbag device 50 according to another embodiment of the present invention in a vehicle mounted state.
7 is a perspective view showing the structure inside the case 16 of the airbag device 50, and FIG. 8 is a sectional view of the airbag device 50.

The airbag device 50 is a passenger airbag device, like the airbag device 10 of the above embodiment. Hereinafter, portions denoted by the same reference numerals as those in the above embodiment have the same configuration unless otherwise described.

In this embodiment, the case 16 has a vertical section U.
It is not shaped like a letter but has a shallow box shape with a flat bottom, and is fixed in the instrument panel 8. The inflator 14 has a case 1 with its axial direction facing the vehicle width direction.
6 is disposed at a substantially central portion in the vehicle longitudinal direction.

The diffuser 52 divides the interior of the case 16 into an airbag storage space 18 and an inflator storage space 20 and distributes gas generated by the inflator 14 to the airbag 1.
2 and is fixed to the bottom of the case 16 in a substantially semi-cylindrical shape so as to surround the inflator 14 with a predetermined gap.

With the arrangement of the inflator 14 and the diffuser 52, the airbag storage space 18 is secured on both the occupant side (vehicle rear side) 18r and the non-occupant side (vehicle front side) 18f with respect to the inflator 14. . The airbag 12 is provided in the front storage space 18f.
The folded part of the bag upper side 12a at the time of deployment
Bag lower side 1 when deployed in rear storage space 18r
The folded portions 2b are housed, respectively, and an airbag portion 12c connecting the two folded portions is arranged over the diffuser 52. As shown in FIG. 6, the airbag 12 housed in this manner is connected to the instrument panel 8.
The space defined by the upper surface and the windshield 6 expands toward the rear of the vehicle.

As shown in FIG. 7, the diffuser 52 also has a first region 36 near the first stage output portion 32 of the inflator 14 and a second region 38 near the second stage output portion 34, as shown in FIG. And the first area 36
Is set smaller than the opening area of the second region 38. Although not shown, a partition wall is provided for partitioning a gap between the inflator 14 and the diffuser 24 into a first area 36 side and a second area 38 side.

In this embodiment, in the first region 36 of the diffuser 52, the center M
The occupant side region R of the diffuser 52 on the occupant side with respect to
The opening area of the non-occupant side region F of the diffuser 52 on the anti-occupant side with respect to the center M is set to be larger than the opening area of the center M. Specifically, the first area 3
6, only one opening 22a is arranged in the non-occupant side region F. In this case, the opening area also means the total opening area of the openings 22 existing in the regions F and R. Therefore, an opening having a smaller opening area may be added to the occupant-side region R together with the opening 22a provided in the non-occupant-side region F. Further, the opening 22a provided in the non-occupant-side region F may slightly extend over the occupant-side region R beyond the center M. The opening 22b of the second region 38 is arranged so as to face substantially upward.

In the airbag device 50 of this embodiment, like the airbag device 10 of the above embodiment, the first
Since the opening area of the region 36 is small, the first output first
The gas output from the step output unit 32 stays while increasing the pressure in the gap between the inflator 14 and the diffuser 52,
Therefore, the amount of gas supplied to the airbag 12 per unit time in the early stage of the operation of the inflator 14 is reduced, and the initial inflation of the airbag 12 can be given a gentleness. Further, since the opening area of the second region 38 is large, it is possible to effectively obtain an output for maintaining a predetermined internal pressure of the airbag during a predetermined time period.

According to the present embodiment, in the first region 36 of the diffuser 52 through which gas from the first stage output section 32 passes, the opening area of the anti-occupant side region F is larger than the opening area of the occupant side region R. Is set large, the amount of gas directly supplied to the airbag 12 expanding toward the occupant in the early stage of the operation of the inflator 14 can be reduced. That is, by directing the gas flow in the early stage of operation of the inflator 14 toward the side wall of the case 16 on the side opposite to the occupant, the gas flow directly in the inflation direction of the airbag 12 can be reduced. This makes it possible to disperse the dynamic pressure of the gas flow when the gas is directly supplied from the inflator 14 to the airbag 12, so that the inflation of the airbag 12 can be moderated.

[0042]

According to the airbag device of the first aspect of the present invention, the opening area of the first region of the diffuser corresponding to the first stage output portion of the inflator is the second region corresponding to the second stage output portion. Is smaller than the opening area of the first stage, the gas generated from the first-stage output portion, which is output first, stays while increasing the pressure in the gap between the inflator and the diffuser, and is thus supplied to the airbag in the early stage of operation of the inflator. It can be adjusted with a tendency to reduce the amount of gas supply per unit time. Thereby, the effect of the delayed output of the multi-stage output type inflator can be enhanced, and a more gentle initial inflation behavior of the airbag can be obtained. Further, since the opening area of the second region is large, it is possible to effectively obtain an output for maintaining a predetermined internal pressure of the airbag during a predetermined time period.

According to the airbag device of the second aspect,
In the first region of the diffuser corresponding to the first-stage output portion of the inflator, the opening area on the side opposite to the occupant is set to be larger than the opening area on the occupant side. The amount of gas supplied directly to the bag can be reduced. Therefore, the dynamic pressure of the gas flow when directly supplied from the inflator to the airbag can be dispersed, so that the inflation of the airbag can be moderated.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an airbag device according to one embodiment of the present invention.

FIG. 2 is a sectional view of the airbag device,
2 shows a cross section taken along line A.

FIG. 3 is a sectional view of the airbag device,
3 shows a cross section taken along line B.

FIG. 4 is a perspective view showing another example of the diffuser in the airbag device.

5 is a cross-sectional view of an airbag device including the diffuser shown in FIG.

FIG. 6 is a cross-sectional view of an airbag device according to another embodiment of the present invention, which is mounted on a vehicle.

FIG. 7 is a perspective view showing a structure inside a case of the airbag device.

FIG. 8 is a sectional view of the airbag device.

[Explanation of symbols]

 10, 50 ... airbag device 12 ... airbag 14 ... inflator 16 ... case 18 ... airbag storage space 18f ... storage space in front of airbag 18r ... storage space behind airbag 20 ... inflator storage space 22 ... opening 22a ... opening in the first region 22b ... opening in the second region 24, 52 ... diffuser 32 ... first stage output unit 34 ... second stage output unit 36 ... second 1 area 38... Second area 40... Partition wall F... Diffuser opposite occupant side area R... Diffuser occupant side area

Continuation of front page (72) Inventor Kazuaki Bito 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka F-term in Toyo Tire & Rubber Co., Ltd. 3D054 AA03 AA14 BB16 BB30 DD15 DD17 FF03 FF16

Claims (4)

[Claims] An airbag, an inflator, a case for accommodating them, and an opening for partitioning the inside of the case into an airbag storage space and an inflator storage space and supplying gas generated by the inflator to the airbag. A diffuser, wherein the inflator includes two output units, a first-stage output unit and a second-stage output unit that output a predetermined delay time, and the diffuser includes A first region near the one-stage output portion and a second region near the second-stage output portion;
An airbag device, wherein the opening area of the region is set smaller than the opening area of the second region. 2. An airbag, an inflator, a case for accommodating them, and an opening for partitioning the interior of the case into an airbag storage space and an inflator storage space and supplying gas generated by the inflator to the airbag. And a diffuser, wherein the inflator includes two output units, a first-stage output unit and a second-stage output unit, which output at a predetermined delay time, and the airbag storage space is The airbag, which is secured on both the occupant side and the non-occupant side with respect to the inflator and is inflated to the occupant side, is stored separately in both of these storage spaces, and the diffuser is provided in the vicinity of the first stage output portion. A first region and a second region near the second stage output section.
An airbag device wherein an opening area on the side opposite to the occupant is set larger than an opening area on the occupant side in the region. 3. The airbag device according to claim 2, wherein an opening area of the first region in the diffuser is set smaller than an opening area of the second region. 4. A partitioning means for partitioning a gap formed between said inflator and said diffuser between said first area and said second area.
Or the airbag device according to 3.