JP2009137529A - Gas generator and airbag module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a phenomenon that a driving force is generated in the case that gas from gas injection holes of an inflator is derived out from a retainer while it is not fixed with a vehicle. <P>SOLUTION: The gas generator 40 of the airbag module is provided with the inflator 41 and the retainer 45. The plurality of gas injection holes 42 are provided for a substantially overall circumference of an outer circumferential surface in a predetermined area about an axial line direction of the cylinder-like inflator 41. The retainer 45 has a cylindrical part 46 and keeps it with the inflator 41 inserted in it and derives the gas G from the gas injection holes 42 out in a direction crossing the axial line L2 via an opening part 48 provided for the cylindrical part 46. An auxiliary opening part 49 for deriving part of the gas G from the gas injection holes 42 in a direction for weakening the driving force generated accompanying the derivation of the gas G from the opening part 48 is provided in a position deviated in a circumferential direction for the opening part 48 which is a substantially same position as the opening part 48 for the axial line direction of the retainer 45. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas generator and an airbag module used in an airbag apparatus such as a side airbag apparatus.

2. Description of the Related Art An airbag device is widely known as a device that protects an occupant from an impact applied to the vehicle. The airbag device includes an airbag module including an airbag stored in a folded state and a gas generator that supplies gas to the airbag to inflate and deploy the airbag. As described in Patent Documents 1 and 2, the gas generator includes an inflator and a retainer. The inflator has a cylindrical shape, and has a plurality of gas ejection holes over a substantially entire circumference of the outer peripheral surface in a predetermined region in the axial direction. When the inflator receives a predetermined operation signal, the inflator operates in accordance with the operation signal, and injects the gas for inflating the airbag from the gas injection hole. The retainer has a cylindrical wall and holds the inflator inserted therein. An opening is provided in the wall portion of the retainer, and the gas from the gas ejection hole is led out to a specific direction among the directions intersecting with the axis of the retainer. The airbag module is used in a state where it is fixed to the vehicle in the retainer of the gas generator.
Registered Utility Model No. 3038153 JP 2005-170362 A

  However, in the airbag module, as described above, the gas ejected from the gas ejection hole of the inflator is led out from the opening of the retainer in a specific direction among the directions intersecting the axis of the retainer. Along with this, a load (propulsive force) in the direction opposite to the direction in which the gas is derived acts on the gas generator as a reaction force of the gas to be ejected.

  On the other hand, in the airbag module, an external factor different from the operation signal, for example, a fire or the like under a situation where the airbag module is not fixed to the vehicle, for example, a situation where the airbag module is stored or transported Can be heated by. In addition, when the gas generator is stored or transported alone, it may be heated by an external factor such as a fire as described above. In any case, when the gas generating agent is heated above its ignition temperature, it ignites regardless of the normal operation signal and generates / injects gas. And there exists a possibility that a gas generator may move unintentionally by the thrust generated with the derivation | leading-out of the said gas.

  The present invention has been made in view of such circumstances, and its purpose is to generate a propulsive force when the gas from the gas injection hole of the inflator is led out from the retainer in a state where it is not fixed to the vehicle. It is an object of the present invention to provide a gas generator and an airbag module that can suppress the phenomenon.

  In order to achieve the above object, the invention described in claim 1 has a cylindrical shape, and the predetermined region in the axial direction has a plurality of gas ejection holes over substantially the entire circumference of the outer peripheral surface in the region. An inflator for injecting a gas for inflating an air bag from the gas injection hole, and a cylindrical wall portion, and holding the inflator in an inserted state therein, and provided on the wall portion A retainer for deriving the gas from the gas ejection hole in a direction crossing its own axis through the opening, and the gas generator used in a state of being fixed to a vehicle, wherein the wall portion of the retainer is At least at a location deviated in the circumferential direction with respect to the opening, a part of the gas from the gas ejection hole is led out in a direction to reduce the propulsive force generated when the gas is led out from the opening. And gist in that a supplementary opening of the fit.

Here, the direction intersecting the axis of the retainer includes not only a direction intersecting (perpendicular) at right angles to the axis but also a direction obliquely intersecting the axis.
According to the above configuration, when gas is ejected from the gas ejection hole of the inflator, a part of the gas is directed to a specific direction among the directions intersecting the axis of the retainer through the opening provided in the wall portion of the retainer. Derived. Along with this, a load (reaction force) in the direction opposite to the direction in which the gas is led out from the opening is generated. If this is the only direction in which gas is led out from the retainer, a force (propulsive force) directed in a specific direction determined by the reaction force is generated in the gas generator.

  However, in the first aspect of the present invention, a part of the gas from the gas ejection hole is formed from the auxiliary opening provided at a location deviated at least in the circumferential direction with respect to the opening of the wall of the retainer. The direction is different from the direction from which the gas is derived from the portion, and is derived in a direction in which the propulsive force generated when the gas is derived from the opening is reduced. Along with this, a load (reaction force) in a direction different from the direction in which the gas is led out through the auxiliary opening is generated. This reaction force acts so as to reduce the reaction force generated when the gas is led out through the opening. Accordingly, the propulsive force acting on the gas generation device is smaller than when the derivation direction is one direction from the opening.

  Therefore, when the gas generating device is stored or transported without being fixed to the vehicle, the gas generating device is heated above the ignition temperature of the inflator due to an external factor such as a fire, and the gas blowing hole of the inflator Even if the gas is ejected from the gas generator, it is possible to suppress a phenomenon in which a propulsive force is generated in the gas generating device as the gas is led out from the retainer to cause an unintended movement.

  According to a second aspect of the present invention, in the first aspect of the invention, when the inflator receives a predetermined operation signal, the inflator operates according to the operation signal and ejects gas. When the inflator is heated above the ignition temperature of the inflator, which is higher than the temperature of the gas derived from the opening during the operation of the inflator, due to different external factors, the gas is ignited and the gas is ejected regardless of the operation signal. The auxiliary opening is provided at substantially the same location as the region in the axial direction of the retainer, and the retainer is provided only when the auxiliary opening is heated to the ignition temperature or higher. The gist is that an opening / closing means for opening the auxiliary opening is further provided.

  According to the above configuration, in the gas generator, gas is ejected from the plurality of gas ejection holes of the inflator. The inflator is covered with a cylindrical wall portion of the retainer from the outside, and this wall portion basically blocks the flow of gas from the gas ejection hole. However, in the second aspect of the present invention, the auxiliary opening is provided in the region (substantially the same as the gas ejection hole) in the axial direction of the retainer to expose a part of the gas ejection holes. Therefore, the gas ejected from the gas ejection hole exposed by the auxiliary opening is vigorously led out in the direction intersecting the axis directly through the auxiliary opening without being blocked by the retainer wall. .

  Here, if the auxiliary opening has a configuration that is always open, during normal use of the gas generator fixed to the vehicle (when the temperature is not heated above the ignition temperature of the inflator due to external factors such as fire) ), The high-temperature gas from the gas ejection hole is vigorously led out through the auxiliary opening. When this gas is blown onto the airbag, the airbag may be damaged greatly. In addition, a part of the gas to be led out in a specific direction out of the directions intersecting the axis of the retainer exclusively from the opening is also led out from the auxiliary opening in a direction different from the direction by the opening. Therefore, there is a possibility that the airbag cannot be inflated and deployed in an intended manner.

  In this respect, in the invention according to claim 2, when the gas is ejected from the gas ejection hole of the inflator in the direction perpendicular to the axis during the normal use of the gas generator fixed to the vehicle, the auxiliary opening The temperature is approximately the same as the temperature of the gas derived from the opening when the inflator is activated. This temperature is lower than the ignition temperature of the inflator. Therefore, the auxiliary opening is closed by the opening / closing means, and the derivation of gas from the auxiliary opening is blocked. A phenomenon in which high-temperature gas is blown to the airbag through the auxiliary opening portion is less likely to occur, and the airbag is less susceptible to major damage. Further, since the gas from the gas ejection holes is not led out from the auxiliary opening but exclusively from the opening, the airbag can be reliably inflated and deployed in the intended manner.

  Further, when the auxiliary opening of the retainer is heated to a temperature higher than the ignition temperature of the inflator due to an external factor such as a fire, the auxiliary opening is opened by the opening / closing means, and the gas can be circulated. A part of the gas ejected from the gas ejection hole passes through the auxiliary opening and is led out in a direction different from the direction by the opening in the direction intersecting the axis. Therefore, the effect of the invention described in claim 1 described above can be obtained.

  The invention according to claim 3 is the invention according to claim 2, wherein the opening / closing means is arranged in a state in which the auxiliary opening is closed and is softened or melted only when heated to the ignition temperature or higher. The gist of the invention is that it comprises an opening and closing member.

  According to the above configuration, when the gas is ejected from the gas ejection hole of the inflator during normal use of the gas generator fixed to the vehicle, the temperature of the auxiliary opening is ejected from the opening when the inflator is activated. It is almost the same as the temperature of the gas and never exceeds the ignition temperature of the inflator. Therefore, the open / close member does not soften or melt and maintains a hard state, receives the gas from the gas ejection hole, and closes the auxiliary opening. This blockage blocks the outflow of gas from the auxiliary opening.

  In addition, if the gas generator that is not fixed to the vehicle encounters an external factor such as a fire, and the auxiliary opening of the retainer is heated above the ignition temperature of the inflator, the opening and closing that closed the auxiliary opening The member softens or melts. When the opening / closing member is blown away by the gas from the gas ejection hole, the auxiliary opening is opened and the gas can be circulated. A part of the gas from the gas ejection hole passes through the auxiliary opening and is led out in a direction different from the direction by the opening in the direction intersecting the axis of the retainer.

  As the opening / closing member, a member formed of a thermoplastic resin as in the invention described in claim 4 is suitable. As such a resin, for example, an olefin resin such as polyethylene, polystyrene, or vinyl chloride resin, polyamide, or the like can be used.

  According to a fifth aspect of the present invention, in the first aspect of the present invention, the auxiliary opening portion is provided in a state of being always opened at a location that is biased in the axial direction of the retainer with respect to the region. The gist.

  According to said structure, in a gas generator, gas is injected in the direction orthogonal to the axis line of the inflator from the several gas injection hole of an inflator. The inflator is covered with a cylindrical wall portion of the retainer from the outside. In addition, in the invention described in claim 5, the auxiliary opening is provided at a position deviated in the axial direction of the retainer with respect to the gas ejection hole, and a part of the gas ejection hole is not exposed. A part of the retainer wall (a portion where the auxiliary opening is not provided) is positioned in the gas injection direction from the gas injection hole, and serves as a barrier for the gas injected from the gas injection hole. For this reason, the gas ejected from the gas ejection hole hits the wall and changes the flow direction to the axial direction. Then, when the gas flows in the axial direction along the wall and reaches the auxiliary opening, the flow direction is changed from the axial direction to the direction intersecting the axial line. The gas is led out through the auxiliary opening in a direction intersecting the axis of the retainer.

  Since the direction of the flow can be changed in this way, the case where the gas from the gas ejection hole is directly derived from the auxiliary opening without changing the direction of the flow (the invention according to claim 2 corresponds to this). However, the momentum of the gas led out from the auxiliary opening is weakened. For this reason, the auxiliary opening is always open, but problems such as those described in the second aspect of the invention are unlikely to occur. That is, problems such as damage to the airbag and difficulty in inflating and deploying the airbag in an intended manner are unlikely to occur.

  According to a sixth aspect of the present invention, there is provided a gas generator, and an airbag that has the gas generator therein and that is inflated by a gas jetted and supplied from the gas generator, and at least the vehicle in the gas generator It is an airbag module used in the state fixed to, Comprising: It makes it a summary to use the gas generator as described in any one of Claims 1-5 as said gas generator.

  According to the above configuration, when the air bag module is not fixed to the vehicle, that is, when it is stored or transported alone, the gas generator is heated by an external factor such as a fire, and the gas of the inflator is Even if gas is ejected from the ejection hole, the same effect as that of the invention described in any one of claims 1 to 5 can be obtained. That is, it is possible to suppress a phenomenon in which a driving force is generated in the gas generation device as the gas is led out from the retainer and the airbag module moves unintentionally.

  According to the gas generator and the airbag module of the present invention, the auxiliary opening is provided at least in the circumferential direction with respect to the opening of the wall portion of the retainer, so that the gas from the inflator is not fixed to the vehicle. Even if it is derived from the retainer, it is possible to suppress a phenomenon in which a driving force is generated and an unintended movement occurs.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
In the following description, the forward direction of the vehicle will be described as the front (front of the vehicle), and the reverse direction of the vehicle will be described as the rear (rear of the vehicle). In the following description, the vertical direction means the vertical direction of the vehicle. In each figure, “front” indicates the front side of the vehicle, “rear” indicates the rear side of the vehicle, “inside” indicates the inside of the vehicle, and “outside” indicates the outside of the vehicle.

  As shown in at least one of FIGS. 1 and 2, a vehicle seat 12 is disposed in the vicinity of the vehicle inner side (upper side in FIG. 2) of the vehicle body side portion 11. Here, the body side portion 11 refers to a member disposed on the side portion of the vehicle, and mainly corresponds to a door, a pillar, and the like. For example, the body side part corresponding to the front seat is a front door, a center pillar (B pillar), or the like. Moreover, the body side part corresponding to a rear seat is the rear part of a side door (rear door), C pillar, the front part of a tire house, a rear quarter, etc.

  An airbag module AM, which is a main part of the side airbag device, is accommodated in a side portion 13A inside the seat back (back) 13 of the vehicle seat 12 and outside the vehicle (the lower side in FIG. 2). . As shown in FIG. 3, the airbag module AM includes an airbag 20 and a gas generator 40. Next, each will be described.

<Airbag 20>
FIG. 3 schematically shows the airbag module AM in a state where the airbag 20 is deployed without being filled with the gas G. FIG. 4 shows a state in the middle of manufacturing the airbag 20.

  As shown in at least one of FIGS. 3 and 4, the airbag 20 includes a panel cloth 22 including a pair of component pieces 21, and a first reinforcing cloth 23 disposed between both component pieces 21 of the panel cloth 22. And a pair of second reinforcing cloths 24 disposed on each component piece 21.

  The panel cloth 22 has a protruding portion 25 that protrudes downward from the boundary portion between the two component pieces 21. The panel cloth 22 is made of a woven cloth formed using a material that has high strength and is flexible and can be folded, for example, polyester yarn, polyamide yarn, or the like.

  The first reinforcing cloth 23 and the second reinforcing cloth 24 are used with the intention of supplementing the strength of each component piece 21 of the panel cloth 22. As the first reinforcing cloth 23, a heat-resistant coating made of an elastomer such as chloroprene and silicone, which is made of a base cloth that has high strength and is flexible and can be folded in the same manner as the airbag 20. A so-called coated cloth having a layer formed on the surface of the base cloth is used. The first reinforcing cloth 23 is stitched to both component pieces 21 of the panel cloth 22 at the upper edge and the lower edge. Moreover, each 2nd reinforcement cloth 24 is stitch | sutured by the component piece 21 of the panel cloth 22 in the peripheral part. In addition, in the figure, the parts 31 and 32 shown with a thick broken line are parts concerning sewing.

  The panel cloth 22 and the first reinforcing cloth 23 are folded in two along a fold line 26 set at the boundary portion between the two component pieces 21 and overlapped. Along with this, the projecting portion 25 is also overlapped at the center portion, and this location becomes a location (mounting portion 27) related to fastening of the gas generator 40. And the pair of component pieces 21 of the panel cloth 22 overlapped as described above are stitched together at their peripheral portions (excluding the protruding portions 25). In the figure, a portion 33 indicated by a thick broken line is a portion related to stitching. By this stitching, the airbag 20 is opened only at the projecting portion 25 and, when inflated and deployed, protects the chest Pt of the occupant P seated on the vehicle seat 12 as shown by a two-dot chain line in FIG. It is formed into a bag of a size and shape that can be made. The size / shape is merely an example, and the airbag 20 may have a size / shape different from the above according to the protected area of the occupant P. Examples of the region to be protected by the airbag 20 include a region from the waist to the chest Pt of the occupant P, a region from the waist to the shoulder, and the like.

  As shown in at least one of FIGS. 3 and 4, both the second reinforcing cloths 24 are stitched to both end portions of a tether (not shown) disposed between the two component pieces 21. By this tether, the expansion in the vehicle width direction when the airbag 20 is inflated and deployed is regulated.

In the airbag 20, an insertion hole 28 through which a bolt 53 of a retainer 45 described later is inserted is formed in the vicinity of the boundary portion between the two component pieces 21.
<Gas generator 40>
As shown in FIG. 5, the gas generation device 40 includes an inflator 41 as a gas generation source, and a retainer 45 attached to the inflator 41.

  In the present embodiment, a type called a pyrotype is used as the inflator 41. As shown in FIGS. 5 and 6A and 6B, the inflator 41 has a cylindrical shape, and when used, the inflator 41 is disposed so that the axis L1 extends substantially in the vertical direction. In this type, a gas generating agent (not shown) that generates an expansion gas G by a chemical reaction accompanied by heat generation is accommodated in the inflator 41. In a predetermined region R in the outer circumferential surface of the inflator 41 along the axis L1 (hereinafter referred to as “axis direction”), the gas G generated by the gas generating agent is perpendicular to the axis L1 (diameter). A plurality of gas ejection holes 42 ejecting in the direction) are provided over substantially the entire circumference of the region R.

A connector portion 43 is provided at a lower end portion of the inflator 41, and a harness 44 serving as an operation signal application wiring to the inflator 41 is connected to the connector portion 43.
When the inflator 41 receives a predetermined operation signal through the harness 44, the inflator 41 ejects the gas G from the gas ejection hole 42 in accordance with the operation signal. The inflator 41 ignites regardless of the operation signal when it is heated to an ignition temperature (200 to 250 ° C.) or higher due to an external factor different from the operation signal, such as a fire. Gas G is ejected. This ignition temperature is higher than the temperature of the gas G ejected from the opening 48 of the retainer 45 when the inflator 41 is operated, and lower than the temperature (600 to 700 ° C.) that can be taken in the event of a fire.

  On the other hand, the retainer 45 is held in a state where the inflator 41 is inserted therein as shown in at least one of FIGS. 5, 7 (A), (B) and FIGS. 8 (A), (B). For the most part, it is formed by bending a plate material such as a metal plate. The retainer 45 has a cylindrical wall part (hereinafter referred to as “cylindrical part 46”) whose upper and lower ends are open, and a substantially semi-cylindrical extending part 47 extending downward from the cylindrical part 46. ing. The cylindrical portion 46 is a portion that wraps around the upper half of the inflator 41, and the extended portion 47 is a portion that covers substantially half of the inflator 41 in the circumferential direction.

  An opening 48 is provided at a location that is substantially the same as the region R in the direction along the axis L <b> 2 of the retainer 45 (hereinafter referred to as “axis direction”) and that is the front side. The opening 48 exposes a part (front side) of the gas ejection hole 42 in the inflator 41 from the cylindrical portion 46.

  Here, as described above, the plurality of gas ejection holes 42 are provided over the entire circumference of the inflator 41, and the portion different from the opening 48 in the cylindrical portion 46 is the gas G from these gas ejection holes 42. The opening 48 allows passage of the gas G from the gas ejection hole 42. Therefore, in the tubular portion 46, the direction (the derivation direction) in which the gas G flows is determined according to the position of the opening 48. In the present embodiment in which the opening 48 is formed on the front side of the cylindrical portion 46, the gas G from the front gas ejection hole 42 exposed at the opening 48 is directly connected to the axis L <b> 2 through the opening 48. It is derived toward a specific direction (substantially forward) among the intersecting directions (see FIG. 10). Further, the gas G from the gas ejection hole 42 that is not exposed flows indirectly along the cylindrical portion 46 and then indirectly through the opening 48 toward a predetermined direction (generally forward of the vehicle) intersecting the axis L2. Are derived.

  A plurality of locations (two locations in the first embodiment) that are substantially the same as the opening 48 in the axial direction of the retainer 45 and that are biased in the circumferential direction with respect to the opening 48 are provided from the gas ejection holes 42. An auxiliary opening 49 is provided for deriving the gas G in a direction different from the direction of the opening 48 in the direction intersecting the axis L2. These auxiliary openings 49 are all open in a circular shape.

  Further, the retainer 45 has an opening / closing means for opening the auxiliary opening 49 only when the auxiliary opening 49 is heated to an ignition temperature (200 to 250 ° C.) or more of the inflator 41 due to an external factor such as a fire. Is provided. The opening / closing means includes an opening / closing member 51 that is arranged with the auxiliary opening 49 closed, and that softens or melts only when heated to the ignition temperature or higher. Therefore, the opening / closing member 51 is in a hard state when the airbag module AM is fixed to the vehicle and is not heated above the ignition temperature due to an external factor such as a fire (hereinafter referred to as “normal use”). The opening / closing member 51 is made of an olefin resin such as polyethylene, polypropylene, polystyrene, or vinyl chloride resin, or a thermoplastic resin such as polyamide, as a material that satisfies these conditions. The opening / closing member 51 is formed by, for example, insert molding using the retainer 45 as an insert, closing the auxiliary opening 49 and being locked to the retainer 45 (see FIG. 10).

  A slit 52 is formed in the extending portion 47 of the retainer 45. Further, a plurality of bolts 53 (two in the first embodiment) extending in a direction orthogonal to the axis L2 are implanted in the cylindrical portion 46 of the retainer 45. These bolts 53 are inserted through the insertion holes 28 of the airbag 20 (see FIGS. 3 and 4). In this state, the gas generation device 40 is located in the airbag 20 in the lower half of the boundary portion between the two component pieces 21, and the lower portion of the gas generation device 40 is located in the mounting portion 27. Then, as shown in FIG. 9, an annular fastener 54 is fitted from the outside of the mounting portion 27, and the fastener 20 is crimped so as to reduce the diameter at a position corresponding to the slit 52. The mounting portion 27 is fastened to the gas generator 40 in an airtight state.

  The airbag module AM having the above configuration is made compact by folding the airbag 20, and is housed in the side portion 13A on the vehicle exterior side of the seat back 13 (see FIGS. 1 and 2). As shown in FIG. 10, the airbag module AM is fixed to the seat frame 58 in the seat back 13 by tightening a nut 55 with a bolt 53 exposed from the airbag 20. In the airbag module AM, the retainer 45 functions as a diffuser that directs the gas G in a predetermined direction, and also has a function of fixing itself in the seat back 13 together with the airbag 20.

  As shown in FIG. 3, the side airbag device includes an impact sensor 56 and a control device 57 in addition to the airbag module AM described above. The impact sensor 56 includes an acceleration sensor or the like, and is provided on the body side portion 11 (see FIG. 2) of the vehicle. The impact sensor 56 detects an impact applied from the side to the body side portion 11. The control device 57 outputs an operation signal to the inflator 41 based on the detection signal from the impact sensor 56.

  As described above, the side airbag device of the present embodiment is configured. In this side airbag device, when an impact of a predetermined value or more is applied to the body side portion 11 of the vehicle and this is detected by the impact sensor 56, an operation signal is output from the control device 57 to the inflator 41 through the harness 44. . By heating based on this operation signal, the gas generating agent in the inflator 41 is ignited to generate a high-temperature and high-pressure gas G. The gas G is uniformly ejected in a direction (radial direction) perpendicular to the axis L1 from a plurality of gas ejection holes 42 provided on the entire circumference of the inflator 41 (see FIG. 6B).

  In the airbag module AM, the tubular portion 46 of the retainer 45 is covered on the inflator 41 from the outside, and this tubular portion 46 basically passes the gas G from the gas ejection hole 42. Block it. However, in the first embodiment, the opening 48 is provided at substantially the same location as the region R (gas ejection hole 42) in the axial direction of the retainer 45, and a part (front side) of the gas ejection holes 42 is exposed. I am letting. Therefore, as shown in FIG. 10, the gas G that is exposed from the opening 48 and is ejected from the gas ejection hole 42 that is directed substantially forward is directly prevented from being blocked by the cylindrical portion 46 of the retainer 45. It passes through the opening 48 and is vigorously derived in a specific direction (substantially forward) among the directions intersecting the axis lines L1 and L2.

  In addition, auxiliary openings 49 are provided at a plurality of locations that are substantially the same as the openings 48 in the axial direction of the retainer 45 and are biased in the circumferential direction with respect to the openings 48. If these auxiliary openings 49 have a configuration that is always open, the high-temperature gas G from the gas ejection holes 42 is vigorously led through the auxiliary openings 49. When the gas G is sprayed onto the airbag 20, the airbag 20 may be damaged greatly. Further, a part of the gas G that should be led out exclusively from the opening 48 in the specific direction (substantially forward) intersecting the axis L2 is led out from the opening 48 through the auxiliary opening 49 in a significantly different direction. The airbag 20 may be difficult to inflate and deploy in the intended manner.

  In this respect, in the first embodiment, as described above, when the gas G is ejected from the gas ejection hole 42 of the inflator 41 in the direction orthogonal to the axis L1, the temperature of the auxiliary opening 49 is opened when the inflator 41 is operated. The temperature is about the same as the temperature of the gas G derived from the section 48 and does not exceed the ignition temperature (200 to 250 ° C.) of the inflator 41. Therefore, the opening / closing member 51 is not softened or melted and maintains a hard state, receives the gas G from the gas ejection holes 42 and continues to close the auxiliary opening 49. By maintaining this closed state, the gas G is prevented from being led out from the auxiliary opening 49. As described above, the phenomenon that the high-temperature gas G is blown to the airbag 20 through the auxiliary opening 49 is less likely to occur.

  Further, the gas G blown from the gas ejection hole 42 to a portion where the opening 48 is not provided in the cylindrical portion 46 of the retainer 45 (including the auxiliary opening 49 closed by the opening / closing member 51) By flowing along the cylindrical portion 46, the direction is changed to a substantially forward direction, and thereafter, it is led out to a specific direction (substantially forward) among the directions intersecting the axis L <b> 2 through the opening 48.

  As described above, the airbag 20 is inflated while the folded state is canceled (deployed) by the high-temperature and high-pressure gas G led out substantially forward from the opening 48. As shown by a two-dot chain line in FIG. 1, the side portion 13 </ b> A on the vehicle exterior side of the seat back 13 is broken and an opening 61 is generated. The airbag 20 jumps out of the seat back 13 through the opening 61. After that, the airbag 20 continues to inflate and deploy, and as shown by a two-dot chain line in FIG. 2, between the outside of the seat back 13, more precisely, between the occupant P and the body side portion 11 entering the vehicle interior. In the space S, it expands and deploys toward the front of the vehicle. The inflated airbag 20 is interposed between the occupant P and the body side portion 11 entering the vehicle interior, and the side impact transmitted to the occupant P's chest Pt through the body side portion 11 is alleviated. The

  By the way, in the airbag module AM including the gas generator 40, the gas G ejected from the gas ejection hole 42 of the inflator 41 passes through the opening 48 and vigorously moves in a predetermined direction intersecting the axis L2 of the retainer 45. When derived, a load (reaction force) in the direction opposite to the direction in which the gas G is derived from the opening 48 is generated. If the gas G is not led out from the retainer 45 in a direction other than the above, a force (propulsive force) directed in a predetermined direction determined by the reaction force is generated in the gas generator 40.

Even if such a propulsive force is generated while the retainer 45 is fixed to the vehicle, there is no possibility that the gas generator 40 will move unintentionally.
On the other hand, in the airbag module AM, the gas generator 40 is heated by an external factor such as a fire in a situation where the retainer 45 is not fixed to the vehicle, for example, in a stored state or a transported state. Can happen. In this case, first, the airbag 20 burns and most of it disappears. And when a gas generating agent becomes more than the ignition temperature (200-250 degreeC), it will ignite and the gas G will be generated and ejected. As the gas G is led out from the opening 48, a propulsive force is generated and the gas generator 40 may move unintentionally.

  However, in the first embodiment, the auxiliary opening 49 is provided at a position that is substantially the same as the opening 48 in the axial direction of the retainer 45 and is deviated in the circumferential direction with respect to the opening 48. The auxiliary opening 49 is closed by an opening / closing member 51 made of thermoplastic resin. However, due to the heat of an external factor such as a fire, the vicinity of the auxiliary opening 49 of the retainer 45 exceeds the ignition temperature of the inflator 41. When heated, the opening / closing member 51 is softened and melted. The opening / closing member 51 in this state is blown away by the gas G from the gas ejection hole 42. As shown in FIG. 11, the auxiliary opening 49 is opened, and the gas G can be circulated.

  A part of the gas G from the gas ejection hole 42 is led out from the auxiliary opening 49 in a direction different from the direction by the opening 48 in the direction intersecting the axis L2 of the retainer 45. Along with this, a load (reaction force) in the direction opposite to the direction in which the gas G is led out from the auxiliary opening 49 is generated. This reaction force acts so as to cancel the reaction force generated with the derivation of the gas G through the opening 48. Accordingly, the force (propulsive force) acting on the gas generator 40 is smaller than when the derivation direction is one direction by the opening 48.

  In order to confirm this effect, the gas generator is attached to an axial force meter to ignite the gas generating agent, and at that time, loads (axial load) generated in three axial directions orthogonal to each other in the gas generator are obtained. Measured for each axial direction. And the momentum (propulsive force) of the gas generator was calculated based on the axial force load for each axial direction. These measurements and calculations were performed for the gas generator 40 of the first embodiment in which the retainer 45 is provided with the auxiliary opening 49 and the conventional gas generator in which the auxiliary opening 49 is not provided. As a result, it was confirmed that the momentum was reduced by about 40% in the gas generator 40 provided with the auxiliary opening 49 compared to the gas generator not provided with the auxiliary opening 49.

  Therefore, when the air bag module AM is stored or transported without being fixed to the vehicle, the gas generator 40 is heated by an external factor such as a fire, and the gas G is discharged from the gas ejection hole 42 of the inflator 41. Even if the gas is ejected from the retainer 45, the gas generator 40 does not move vigorously.

  Incidentally, when the burner test (also called a direct fire test) was performed on the airbag module AM, the amount of movement of the gas generator 40 in the first embodiment was smaller than the allowable value. As a comparative example, an air bag module using a conventional gas generator without an auxiliary opening 49 was subjected to a similar burner test. As a result, the amount of movement of the gas generator was larger than an allowable value. .

  Here, in the burner test, the air bag module AM is placed on the test stand net, and the flame of a plurality of (three) burners is applied to the air bag module AM from below the net to ignite the gas generating agent. In this case, the amount of movement (flight) of the gas generator 40 is measured. In this test method, the allowable value for movement (flight amount) is 4 m.

According to the first embodiment described in detail above, the following effects can be obtained.
(1) A portion of the gas G from the gas ejection hole 42 is propelled along with the derivation of the gas G from the opening 48 at a location biased in the circumferential direction with respect to the opening 48 of the cylindrical portion 46. An auxiliary opening 49 for leading out in the direction of decreasing is provided. Therefore, when the airbag module AM is stored or transported without being fixed to the vehicle, the gas generator 40 is heated to a temperature higher than the ignition temperature of the inflator 41 due to an external factor such as a fire, and the gas ejection hole Even if the gas G is ejected from 42 and led out from the retainer 45, it is possible to suppress generation of a large propulsive force in the gas generator 40. As a result, a phenomenon in which the gas generator 40 moves unintentionally can be suppressed.

  (2) In the first embodiment in which the auxiliary opening 49 is provided at substantially the same location as the region R in the axial direction of the retainer 45, the same applies only when the auxiliary opening 49 is heated above the ignition temperature of the inflator 41. A configuration in which the auxiliary opening 49 is opened is adopted. This ignition temperature is higher than the temperature of the gas G derived from the opening 48 when the inflator 41 is operated.

  Therefore, at the time of normal use with the airbag module AM fixed to the vehicle in the seat frame 58, the auxiliary opening 49 can be closed and the derivation of the gas G from the auxiliary opening 49 can be blocked. . The phenomenon that the high-temperature gas G is blown to the airbag 20 through the auxiliary opening 49 is less likely to occur, and a problem that the airbag 20 is significantly damaged can be suppressed. Further, since the gas G from the gas ejection hole 42 is not led out from the auxiliary opening 49 but exclusively from the opening 48, the airbag 20 can be inflated and deployed in an intended manner.

  Further, in the event of a fire in a state where the airbag module AM is not fixed to the vehicle, the auxiliary opening 49 is opened to allow the gas G to be led out, so that the effect (1) can be obtained.

  (3) In order to realize the configuration of (2), an opening / closing member 51 that softens or melts only when heated to an ignition temperature (200 to 250 ° C.) or higher of the inflator 41 is used. The opening 49 is closed. During normal use with the airbag module AM fixed to the vehicle, the auxiliary opening 49 can be closed by making the opening / closing member 51 hard. When the air bag module AM is not fixed to the vehicle and heat is applied due to an external factor such as a fire, the opening / closing member 51 can be softened or melted to open the auxiliary opening 49. Therefore, the effect (2) can be reliably achieved.

(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIGS.

As shown in FIGS. 12A and 12B, the second embodiment is different from the first embodiment described above in the form of the retainer 45, more specifically, the positions of the opening 48 and the auxiliary opening 49. .
That is, in the second embodiment, the opening 48 is provided at a location that is deviated in the axial direction of the retainer 45 with respect to the region R in which the gas ejection hole 42 is provided. In other words, a part of the cylindrical portion 46 is located at a position corresponding to the region R in the retainer 45, and none of the plurality of gas ejection holes 42 is exposed from the retainer 45. In this regard, the second embodiment is different from the first embodiment in which the gas jet holes 42 located on the front side are exposed. In the second embodiment, the opening 48 is provided at a location slightly deviated downward from the region R in the axial direction of the retainer 45.

  On the other hand, the auxiliary opening 49 is provided at substantially the same location as the opening 48 in the axial direction of the retainer 45. This location is a location that deviates in the axial direction (downward) of the retainer 45 with respect to the region R where the gas ejection holes 42 exist. Therefore, the auxiliary opening 49 is located at a location different from that in the first embodiment. The auxiliary opening 49 is always open. In this respect, the second embodiment is different from the first embodiment in which the auxiliary opening 49 is closed by the opening / closing member 51.

Matters other than the above are the same as in the first embodiment. Therefore, in 2nd Embodiment, the same code | symbol is attached | subjected about the location and member similar to 1st Embodiment, and detailed description is abbreviate | omitted.
According to the second embodiment having the above configuration, in the airbag module AM, the gas G is ejected from the plurality of gas ejection holes 42 of the inflator 41 in a direction (radial direction) perpendicular to the axis L1 (FIG. 6 ( B)). The inflator 41 is covered with a cylindrical portion 46 of the retainer 45 from the outside. Moreover, in the second embodiment, unlike the first embodiment described above, the opening 48 and the auxiliary opening 49 are provided at locations that are biased in the axial direction of the retainer 45 with respect to the gas ejection holes 42. The gas ejection hole 42 is not exposed from the retainer 45. In the direction (radial direction) perpendicular to the axis L1 of the gas ejection hole 42, a part of the cylindrical portion 46 of the retainer 45 (a portion where the opening 48 and the auxiliary opening 49 are not provided) is located. It becomes a barrier for the gas G ejected from the gas ejection holes 42. For this reason, the gas G ejected from the gas ejection hole 42 in the direction (radial direction) perpendicular to the axis L1 strikes the cylindrical portion 46 and changes the flow direction from the direction perpendicular to the axis L1 to the axial direction (downward). Change to).

  The gas G flows in the axial direction along the cylindrical portion 46, and when the gas G reaches the opening 48 or the auxiliary opening 49, the direction of the flow is changed from the axial direction to the direction intersecting the axis L2. The gas G is led out in a direction intersecting the axis L2 of the retainer 45 through the opening 48 or the auxiliary opening 49. Since the flow direction can be changed in this way, the auxiliary opening is more than in the case where the gas G from the gas ejection hole 42 is directly led out from the auxiliary opening 49 without changing the flow direction (first embodiment). The momentum of the gas G derived from the portion 49 is weakened. Therefore, although the auxiliary opening 49 is always open, the problem as described in the first embodiment, that is, the airbag 20 is damaged, and the airbag 20 can be inflated and deployed in an intended manner. Problems such as difficulty are unlikely to occur.

  Also in the second embodiment, in order to confirm the propulsive force reduction effect, the axial force load was measured using the axial force meter and the momentum was calculated in the same manner as in the first embodiment. As a result, it was found that the momentum can be reduced by about 55% in the gas generator 40 of the second embodiment compared to the conventional gas generator in which the auxiliary opening 49 is not provided.

Therefore, according to the second embodiment, the auxiliary opening 49 is not closed by the opening / closing member 51, but the same effect as (1) in the first embodiment can be obtained.
In addition, since the gas ejection hole 42 is not exposed, and the opening 48 is provided at a position deviated from the gas ejection hole 42 in the axial direction of the retainer 45, the momentum at which the gas G blows out from the opening 48 is high. This is slightly weaker than in the first embodiment. However, the decrease in the momentum does not hinder the inflation and deployment of the airbag 20.

The present invention can be embodied in another embodiment described below.
In the first and second embodiments described above, the case where the airbag module AM encounters an external factor such as a fire during storage or transportation has been mainly described, but the gas generator 40 may be stored alone. There may be scenes that are transported. Since the gas generator 40 is merely a form in the previous stage of the airbag module AM (form before being attached to the airbag 20), the same effects as in the first and second embodiments can be obtained in this case as well.

  In the gas generator 40, as shown in FIG. 13A, the opening 48 and the auxiliary opening 49 of the retainer 45 obliquely intersect part of the gas G from the inflator 41 with the axis L2 of the retainer 45. It may be derived in the direction.

  As shown in FIG. 13B, the auxiliary openings 49 are provided at a plurality of locations that are biased in the direction along the axis L2 (axial direction) with respect to the openings 48 of the retainer 45 and that are mutually biased in the coaxial line direction. May be. In the case where there are a plurality of auxiliary openings 49, the propulsive force generated along with the derivation of the gas G from the openings 48 is reduced by the gas G derived from all the auxiliary openings 49.

  The opening shape of the auxiliary opening 49 is not particularly limited. For example, the circular shape employed in each of the above embodiments may be used, or a non-circular shape may be used. Examples of non-circular opening shapes include polygons and ellipses.

  Further, the number of auxiliary openings 49 is not particularly limited. One or more is sufficient, and even in one case, the effect of reducing the propulsive force generated in the gas generator 40 can be obtained as compared with the case where no auxiliary opening 49 is provided.

  -As an opening-and-closing means, you may employ | adopt what has a different structure from 1st Embodiment. For example, an opening / closing member that is made of a flame-retardant material and that can move between a position where the auxiliary opening 49 is closed and a position where the auxiliary opening 49 is opened is provided. Then, the actuator holds the opening / closing member in the closed position during normal use of the gas generator 40, and when not (when heated above the ignition temperature due to an external factor such as a fire), the opening / closing member is opened. You may make it move to.

  The opening / closing member 51 in the first embodiment blocks the gas G from passing through the auxiliary opening 49 during normal use in which the airbag module AM is fixed to the seat frame 58, and is not during normal use (for example, Anything that satisfies the condition that it can be allowed to pass during a fire) is acceptable.

  Therefore, the shape, size, thickness, position, attachment mode, and the like of the opening / closing member 51 may be changed within a range that satisfies this condition. For example, the position of the opening / closing member 51 in the direction (radial direction) orthogonal to the axis L <b> 2 of the retainer 45 may be the same position as the auxiliary opening 49 or may be inside the auxiliary opening 49. It may be good or outside.

  If the position in the direction perpendicular to the axis L2 is inside or outside the auxiliary opening 49, is the opening / closing member 51 the same as the auxiliary opening 49 in order to completely close the auxiliary opening 49 by the opening / closing member 51? It must have a larger size. If this condition is satisfied, there is no particular limitation on the size. The same applies to the shape of the opening / closing member 51, and the opening / closing member 51 may have a shape significantly different from that of the auxiliary opening 49.

The opening / closing member 51 may be bonded and fixed to the retainer 45. Instead of this, the retainer 45 may be provided with a locking portion, and the opening / closing member 51 may be locked to the locking portion.
The opening / closing member 51 may not be burned by the heat of the gas G from the inflator 41 but burned and lost by the heat of an external factor such as a fire.

  The panel cloth 22 is composed of a plurality of component pieces 21 provided independently of each other, and the airbag 20 is formed by stacking the plurality of component pieces 21 and by means such as stitching at the peripheral edge thereof. It may be combined.

  The airbag 20 may be one in which the peripheral portions of the pair of component pieces 21 of the panel cloth 22 are joined by bonding instead of stitching. Similarly, at least one of the first reinforcing cloth 23 and the second reinforcing cloth 24 may be bonded to the panel cloth 22 by adhesion instead of stitching.

  As the inflator, a type different from the above pyro type may be used. Such types include the strado gas type that breaks the bulkhead of a high-pressure gas cylinder filled with high-pressure gas with gunpowder etc., and the hybrid type that combines both the pyro and strado gas types. Can be mentioned.

  -This invention can also be embodied in the gas generator used for airbag apparatuses other than a side airbag apparatus, and an airbag module. Examples of such airbag devices include curtain shield airbag devices, passenger seat airbag devices, and the like.

1 is a schematic side view showing a vehicle seat to which a side airbag device is applied in a first embodiment embodying the present invention. In 1st Embodiment, the schematic plan view explaining the positional relationship of a vehicle seat and a body side part. In the first embodiment, a partially broken side view showing the airbag module in a state where the airbag is deployed without being filled with gas. The front view which shows the state before folding the panel cloth in the airbag module of FIG. The perspective view which shows the state before an inflator is inserted and hold | maintained at the retainer in 1st Embodiment. (A) is a side view of the inflator in 1st Embodiment, (B) is a top view which shows the state in which gas is ejected from the gas ejection hole of the inflator. (A) is a side view of the retainer in 1st Embodiment, (B) is a rear view of the retainer. (A) is a side view of the gas generator in 1st Embodiment, (B) is a rear view of the gas generator. The rear view which shows the airbag module in the state by which the airbag was folded in 1st Embodiment. In 1st Embodiment, the schematic plane sectional view explaining the effect | action of the gas generator at the time of normal use. In 1st Embodiment, the schematic plane sectional view explaining an effect | action of the gas generator when the gas generator is heated by external factors, such as a fire. It is a figure which shows a gas generator corresponding to FIG. 8 in 2nd Embodiment which actualized this invention, (A) is a side view, (B) is a rear view. (A), (B) is a schematic block diagram explaining another embodiment of a gas generator.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Air bag, 40 ... Gas generator, 41 ... Inflator, 42 ... Gas ejection hole, 45 ... Retainer, 46 ... Cylindrical part (wall part), 48 ... Opening part, 49 ... Auxiliary opening part, 51 ... Opening / closing member (Opening / closing means), AM ... airbag module, G ... gas, L1 ... inflator axis, L2 ... retainer axis, R ... region.

Claims (6)

An inflator that has a cylindrical shape and a plurality of gas ejection holes are provided in a predetermined region in the axial direction over substantially the entire circumference of the outer circumferential surface in the region, and gas for inflating an airbag is ejected from the gas ejection holes When,
It has a cylindrical wall portion, and holds the inflator inserted therein, and through the opening provided in the wall portion, the gas from the gas ejection hole crosses its own axis. A gas generator including a retainer for deriving and used in a state of being fixed to a vehicle;
In a portion of the retainer that is biased in the circumferential direction at least in the circumferential direction with respect to the opening, a part of the gas from the gas ejection hole is reduced, and the propulsive force that is generated by the derivation of gas from the opening is reduced. A gas generator characterized in that an auxiliary opening is provided to lead out in a direction to perform. When the inflator receives a predetermined operation signal, the inflator operates according to the operation signal and ejects gas. On the other hand, the inflator is led out from the opening when the inflator is operated due to an external factor different from the operation signal. When heated above the ignition temperature of the inflator, which is higher than the temperature of the gas to be ignited, the gas is ignited and the gas is ejected regardless of the operation signal,
The auxiliary opening is provided at substantially the same location as the region in the axial direction of the retainer,
The gas generator according to claim 1, wherein the retainer is further provided with opening / closing means that opens the auxiliary opening only when the auxiliary opening is heated to the ignition temperature or higher. The gas generating device according to claim 2, wherein the opening / closing means includes an opening / closing member that is disposed in a state where the auxiliary opening is closed and that softens or melts only when heated to the ignition temperature or higher. The gas generator according to claim 3, wherein the opening / closing member is formed of a thermoplastic resin. The gas generator according to claim 1, wherein the auxiliary opening portion is provided in a state of being always opened at a location that is biased in the axial direction of the retainer with respect to the region. A gas generator and an air bag which has the gas generator inside and which is inflated by a gas jetted and supplied from the gas generator, and used at least in a state fixed to the vehicle in the gas generator An airbag module,
An air bag module using the gas generating device according to any one of claims 1 to 5 as the gas generating device.

Images