JP2014184835A - Inflator for airbag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently use the energy of transfer charge.SOLUTION: In a pressure container 2 joining and integrating an adaptor 2b and diffuser 2a on a base 2c, at least an ignitor 3 supported by the adaptor 2b, and an ignitor tube 6 supported by the adaptor 2b or the base 2c are provided. The ignitor 3 and transfer charge 4 are stored on an inner peripheral side of an ignitor tube 6, and a gas generating agent 5 is charged on an outer peripheral side. A partition wall such as a cover 14 for sealing a storing space 13 of the transfer charge 4 is provided above the ignitor tube 6. The cover 14 is equipped with a projecting-shaped portion 14a which is an inclined surface symmetric to a center axis about a cross section orthogonal to the axial center axis of the ignitor tube 6. Therefore, the use amount of the transfer charge can be reduced.

Description

  The present invention relates to an inflator that generates gas to be supplied to an airbag installed in an automobile as a safety device.

  The airbag device protects an occupant from an impact at the time of collision by deploying the airbag with gas generated by an inflator.

  FIG. 7 is a central longitudinal sectional view for explaining an example of the structure of the single stage type inflator 1 and is configured as follows, for example. 2 is a pressure vessel composed of a diffuser 2a, an adapter 2b, and a base 2c. An igniter 3 that is activated by a collision detection signal, a transfer agent 4 that amplifies the ignition energy of the igniter 3 instantaneously, and a large amount of gas is instantaneously generated. The gas generating agent 5 is built in.

  At the time of the collision, the gas generating agent 5 is ignited by the igniter 3 through the transfer powder 4, and the generated gas is ejected from the gas ejection holes 2aa provided on the side wall of the diffuser 2a to deploy the airbag. In addition, 6 in FIG. 7 is an igniter tube attached to the base 2c so as to partition the charge transfer agent 4 and the gas generating agent 5.

  At that time, in the invention disclosed in Patent Document 1, the collection of the solid residue contained in the generated gas and the cooling of the gas are once guided to the annular space 7 provided above the gas generating agent 5, and then the gas This is done by ejecting from the gas ejection hole 2aa via the flow path 8.

  When the annular space 7 is provided above the gas generating agent 5 as in the invention disclosed in Patent Document 1, the igniter tube 6 that accommodates the transfer powder 4 is higher than the height of the space in which the gas generating agent 5 is charged. Height increases.

  In the case of such a structure, since the gas generating agent starts to combust when the transfer charge stored above the igniter tube starts to burn, the transfer charge stored above the igniter tube cannot be fully utilized. In some cases, the gas generating agent cannot be combusted within a predetermined time.

  It should be noted that the height of the gas generating agent charging space may be increased so that the explosive charge storage space and the gas generating agent charging space have the same height, but in this case, the height of the pressure vessel increases. As a result, the inflator becomes larger.

JP 2012-61960 A

  The problem to be solved by the present invention is that in the case of the inflator disclosed in Patent Document 1, it is not possible to sufficiently use the transfer charge contained above the igniter tube, and the gas generating agent is burned efficiently in a short time. It is a point that can not be done.

The inflator for an airbag of the present invention is
In order to enable the efficient use of explosives contained in igniter tubes,
In the pressure vessel that joins and integrates an adapter and a diffuser to the base, at least an igniter supported by the adapter and an igniter tube supported by the adapter or the base are installed, and on the inner peripheral side of the igniter tube An inflator for an air bag containing the igniter and a charge transfer agent and charged with a gas generating agent on the outer peripheral side,
The partition wall is provided above the igniter tube, and the partition wall is inclined with respect to a cross section perpendicular to the axial center axis of the igniter tube. The most important feature is having

  That is, in the present invention, the partition wall that seals the storage space for the charge transfer agent is provided with an inclined surface that is symmetric with respect to the central axis with respect to a cross section orthogonal to the axial center axis of the igniter tube. A preferable combustion state can be obtained by directing thermal energy in an arbitrary direction.

  The inclined surface formed on the partition wall that seals the space for storing the charge transfer agent may have a convex shape toward the space for storing the charge transfer agent or a convex shape toward the outside of the space for the transfer charge transfer. As this convex shape, for example, a dome shape or a conical shape can be considered. Moreover, a thing which has a horizontal part in the convex skirt part of the said inclined surface may be sufficient.

  When the inclined surface has a convex shape toward the space for storing the charge, the energy of the charge can be guided in the peripheral direction (outer peripheral side) in the igniter tube. Thereby, a flame can be efficiently guide | induced to the bottom of an igniter tube. In addition, when the inclined surface has a convex shape toward the outside of the space for storing the charge, the energy of the charge is once concentrated in the center and can be discharged toward the peripheral direction (outer peripheral side) in the igniter tube. Again, the flame can be efficiently guided throughout the igniter tube.

  In the present invention, the thermal energy of the charge transfer agent is once concentrated in the center, or directly propagated / released toward the outer peripheral side, so that the pressure rise in the igniter tube increases and the thermal energy toward the outer peripheral side increases. Become. Therefore, the amount of transfer charge used can be reduced.

It is a center longitudinal cross-sectional view of the 1st Example of the inflator of this invention. It is a figure explaining an example of propagation of the heat energy at the time of ignition of the transfer powder in the inflator of the present invention. (A)-(g) is the figure which showed the other Example of the partition wall which is a component of the inflator of this invention. It is a figure explaining the other example of propagation of the thermal energy at the time of igniting the charge transfer in the inflator of this invention. It is a center longitudinal cross-sectional view of the 2nd Example of the inflator of this invention. It is a center longitudinal cross-sectional view of the 3rd Example of the inflator of this invention. It is a center longitudinal cross-sectional view of the conventional inflator.

  In the present invention, for the purpose of enabling efficient use of the charge transfer agent accommodated in the igniter tube, the partition wall that seals the charge transfer agent storage space is provided with respect to a cross section orthogonal to the axial central axis of the igniter tube. This is achieved by providing a symmetrical inclined surface on the central axis.

Embodiments of the present invention will be described below with reference to FIGS.
FIG. 1 is a central longitudinal sectional view of a first embodiment of an inflator of the present invention.

  Reference numeral 11 denotes an inflator for an air bag according to the present invention. For example, an igniter 3 and a transfer charge 4 in a pressure vessel 2 in which an adapter 2b holding an igniter tube 6 and a diffuser 2a are joined and integrated with a base 2c. And a gas generating agent 5 and a filter 12 are provided.

  Among these, the igniter 3 that is operated by an electric signal is supported by the adapter 2b. The filter 12 is arranged along the inner peripheral side of the side wall of the pressure vessel 2. Further, the igniter 3 and the transfer powder 4 combusted by the ignition energy of the stirrer 3 are accommodated on the inner peripheral side of the igniter tube 6, while the gas is generated by the combustion heat of the transfer powder 4 The agent 5 is inserted between the outer peripheral side of the igniter tube 6 and the filter 12. A space 15 in which the gas generating agent 5 is charged (hereinafter referred to as a charging space) 15 is covered with a retainer 16.

  In the present invention, a partition wall that seals the igniter tube 6 that forms the space (hereinafter referred to as “accommodating space”) 13 in which the charge transfer material 4 is accommodated, for example, a lid 14 is attached to the upper portion of the igniter tube 6 by fitting. Yes.

  The side of the lid 14 facing the accommodation space 13 is directed to an inclined surface symmetric with respect to the axial center axis with respect to a cross section orthogonal to the axial center axis of the igniter tube 6, for example, outside the accommodation space 13. It has a dome-like convex shape. Hereinafter, the convex inclined surface is referred to as a convex portion 14a.

  When the housing space 13 is sealed with the lid 14 having such a convex portion 14a, the thermal energy generated when the transfer charge 4 burns is temporarily as shown by the arrow in the upper diagram of FIG. The center of the lid 14 (the central portion in the axial direction of the igniter tube 6) is concentrated.

  Due to the concentration of the heat energy, the pressure rise in the igniter tube 6 increases, and the combustion heat is scattered with a larger energy toward the outer peripheral side of the igniter tube 6 as indicated by an arrow in the lower diagram of FIG. The scattered combustion heat is ejected from an opening 6 a provided on the side wall of the igniter tube 6 to ignite the gas generating agent 5.

  Therefore, the lid 14 having the above-described action is preferably made thicker than the igniter tube 6 so that the lid 14 is not deformed by the thermal energy generated when the transfer charge 4 burns. Good.

  As described above, according to the inflator 11 of the present invention, since the thermal energy of the transfer powder 4 can be efficiently transmitted to the gas generating agent 5, the transfer powder 4 accommodated in the igniter tube 6 can be used efficiently. Can do.

  Therefore, the explosive 4 to be used can be reduced with the efficient use of the explosive 4. And with the reduction of the usage-amount of the charge transfer agent 4, the influence of a transfer charge reduces and the variation at the time of igniting the gas generating agent 5 also decreases.

  The present invention is not limited to the above examples, and it goes without saying that the embodiments may be appropriately changed as long as they are included in the scope of the technical idea described in each claim.

  As long as the transfer charge 4 is combusted, the convex portion 14a formed on the side of the lid 14 facing the accommodation space 13 can be accommodated as long as the heat energy concentration efficiency in the accommodation space 13 can be increased. The shape is not limited to the dome shape toward the outside of the space 13.

  For example, as shown to Fig.3 (a), the cone shape which goes outside the accommodation space 13 may be sufficient. Moreover, the cone shape (FIG.3 (b)) and dome shape (FIG.3 (c)) which go to the accommodation space 13 may be sufficient. Further, as shown in FIGS. 3D to 3F, a horizontal portion 14b may be provided at the base of the convex portion 14a shown in FIGS. 1 and 3A to 3C.

  Incidentally, when the convex portion 14a is formed in a dome shape toward the accommodation space 13 as shown in FIG. 3 (c), the thermal energy generated when the transfer charge 4 burns is transferred in the peripheral direction in the igniter tube 6. (See the arrow in the upper diagram of FIG. 4).

  As a result, as shown by the arrow in the lower drawing of FIG. 4, the flame can be efficiently guided to the bottom of the igniter tube 6, and the transfer charge 4 accommodated below the igniter tube 6 is fully utilized. can do.

  Moreover, in the said 1st Example, although the lid | cover 14 which seals the accommodation space 13 of the charge transfer agent 4, and the retainer 16 which covers the charging space 15 of the gas generating agent 5 are comprised separately, it shows in FIG. As described above, the retainer 16 and the lid 14 may be integrally formed.

  That is, the airbag inflator described above is a preferred example of the present invention, and other embodiments can be implemented or performed by various methods. In particular, the present invention is not limited to the detailed shape, size, configuration, and the like of the components shown in the accompanying drawings unless otherwise specified in the present specification. In addition, expressions and terms used in the present specification are for the purpose of explanation, and are not limited thereto unless specifically limited.

  For example, in the first and second embodiments, the inflator 11 of the type in which the solid residue contained in the generated gas is collected and the gas is cooled by the filter 12 is described. However, the present invention can also be applied to an inflator of a type not provided with a filter as described in the prior art, for example, as shown in FIG. In the third embodiment shown in FIG. 6, the retainer 16 and the lid 14 in which the convex portion 14 a is conical toward the outside of the accommodation space 13 are integrally formed. In this third embodiment, the generated gas passes through the through hole 16a provided in the retainer 16 and reaches the space 17 formed above the charging space 15, and then the outer cylinder 18 and the inner surface of the side wall of the diffuser 2a. It ejects from the gas ejection hole 2aa through the gas flow path 8 formed therebetween.

  In this specification, the single stage type inflator has been described. However, the present invention can also be applied to a double stage type inflator.

2 pressure vessel 2a diffuser 2b adapter 2c base 3 igniter 4 explosive charge 5 gas generating agent 6 igniter tube 11 inflator 13 charging space 14 lid 14a convex shape portion 14b horizontal portion 15 charging space 16 retainer

Claims (10)

In the pressure vessel that joins and integrates an adapter and a diffuser to the base, at least an igniter supported by the adapter and an igniter tube supported by the adapter or the base are installed, and on the inner peripheral side of the igniter tube An inflator for an air bag containing the igniter and a charge transfer agent and charged with a gas generating agent on the outer peripheral side,
The partition wall is provided above the igniter tube, and the partition wall is inclined with respect to a cross section perpendicular to the axial center axis of the igniter tube. An inflator for an air bag comprising:   The inflator for an airbag according to claim 1, wherein the inclined surface of the partition wall has a convex shape toward the charging space for the transfer charge.   The inflator for an airbag according to claim 1, wherein the inclined surface of the partition wall has a convex shape toward the outside of the charging space for the transfer charge.   The inflator for an airbag according to claim 2 or 3, wherein the convex shape of the inclined surface is a dome shape.   4. The airbag inflator according to claim 2, wherein the convex shape of the inclined surface is a conical shape.   The inflator for an airbag according to any one of claims 2 to 5, further comprising a horizontal portion at a convex skirt portion of the inclined surface.   The inflator for an airbag according to any one of claims 2 to 6, wherein the partition wall is a lid provided on an upper portion of an igniter tube.   The inflator for an air bag according to claim 7, further comprising a retainer that covers a space in which the gas generating agent is charged, and the retainer is configured separately from the lid.   The inflator for an airbag according to claim 7, further comprising a retainer that covers a space in which the gas generating agent is charged, and the retainer is formed integrally with the lid.   The inflator for an airbag according to any one of claims 7 to 9, wherein a thickness of the lid is thicker than a thickness of the igniter tube.

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