JP2015058909A - Inflator for air-bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air-bag inflator for suppressing the inclinations of a pre-fitted igniter tube and a second cup as much as possible while reducing a press-in load.SOLUTION: An inflator generates an expanding gas for an air-bag. The inflator comprises: a pressure container 2, in which a diffuser 2a having an exhaust nozzle 2aa for a gas generated in the inflator is jointed to a base 2b having adaptors 2c and 2d jointed; igniter parts 3 and 4 having igniters 3a and 4a accommodated in an igniter tube 7 and a second cup 8 press-fitted in the adaptors 2c and 2d; and gas generating agents 5a and 5b accommodated in a gas generating agent filling part which can be ignited from the igniter parts 3 and 4. Two-stage tapers 2cc and 2cd, and 2dc and 2dd are formed in the pressure-pressed parts 2cb and 2db of the adapters 2c and 2d, in which an igniter tube 7 and a second cup 8 are press-fitted. Even if the press-in load is made small, the centering accuracy of the igniter tube and the second cup can be improved.

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 during a collision by deploying the airbag with gas generated by an inflator.

  FIG. 3 is a central longitudinal sectional view for explaining an example of a dual stage type inflator having two igniters. The inflator 1 includes a first and second igniter portions 3 and 4 in a pressure vessel 2 and first and second gas generating agents 5a that are ignited by the igniter portions 3 and 4 to generate gas. , 5b and a filter 6 for adsorbing the solid residue in the generated gas.

  Of these, the pressure vessel 2 is composed of a diffuser 2a and a base 2b connected to the diffuser 2a. A gas injection hole 2aa is formed on the side wall of the diffuser 2a, while two adapters are provided on the base 2b. 2c and 2d are joined.

  The first igniter 3 instantaneously converts the igniter 3a attached to the one adapter 2c inside the igniter tube 7 fitted to the one adapter 2c, and the ignition energy of the igniter 3a. It is the structure which accommodated the explosive charge 3b which amplifies to.

  On the other hand, the 2nd igniter part 4 is the structure which accommodated the igniter 4a attached to the said other adapter 2d inside the 2nd cup 8 fitted to the said other adapter 2d. The 2nd cup 8 includes a cap 8a having a side wall provided with a communication hole 8aa and a tube 8b whose upper portion is covered with the cap 8a.

  The second gas generating agent 5 b is charged in a second gas generating agent filling portion inside the 2nd cup 8. The first gas generating agent 5 a is inserted into the first gas generating agent filling portion inside the first cup 9 inserted above the igniter tube 7 and the outer peripheral portion of the second cup 8. A communication hole 9a is formed on the bottom wall of the 1st cup 9 to transmit the ignition of the transfer charge 3b to the first gas generating agent 5a.

  When the inflator 1 determines that the detected collision energy value is not too dangerous, the inflator 1 operates only the igniter 3a of the first igniter section 3 to ignite the transfer charge 3b, and passes through the communication hole 9a of the 1st cup 9. The first gas generating agent 5a is ignited to generate gas. The generated gas is ejected from the ejection hole 2aa of the diffuser 2a through the filter 6 to deploy the airbag.

  On the other hand, when it is determined that the detected collision energy value is dangerous, the igniter 3a of the first igniter unit 3 and the igniter 4a of the second igniter unit 4 are operated together to generate the first and second gases. The agents 5a and 5b are ignited, a large amount of gas is generated, and the airbag is deployed at a high speed.

  The gas generated by the ignition of the second gas generating agent 5b reaches the first gas generating agent filling portion from the communication hole 8aa of the cap 8a, and is ejected from the ejection hole 2aa of the diffuser 2a through the filter 6.

  3 in FIG. 3 is a glass fiber cushion member installed inside the ceiling wall of the diffuser 2a for the purpose of preventing the first gas generating agent 5a from moving due to vibration of the inflator 1 to prevent deformation and the like. .

  Incidentally, the igniter tube and the 2nd cup are generally attached to the adapter in the inflator by press-fitting (see, for example, the sixth line of paragraph 0033 of Patent Document 1).

  When galling occurs at the initial press-fitting time of this igniter tube or 2nd cup, or when a burr generated by galling or the like is caught in the contact surface between the adapter and igniter tube or 2nd cup, the press-fitting load is large. There is a problem of becoming.

  Therefore, the press-fitting start ends of the press-fitted portions of the adapters 2c and 2d are formed in the convex curves 2ca and 2da shown in FIG. 3 or the taper described in Patent Document 1 to prevent galling or the like during press-fitting. . Further, a lubricant is applied to the parallel portion following the press-fitting start end to reduce the press-fitting load.

  At that time, in order to further reduce the press-fitting load, it is conceivable to shorten the length of the parallel portion, but in order to shorten the length of the parallel portion, the convex curved portion formed at the press-fitting start end is used. It is necessary to increase the length or the length of the tapered portion.

  However, when the convex curved part is enlarged or the length of the tapered part is shortened and the length of the parallel part is shortened, the gap between the adapter and the igniter tube or 2nd cup in the convex curved part or the tapered part. Increases and the centering accuracy deteriorates.

  If the centering accuracy deteriorates, in the case of dual stage type inflators, the igniter tube and the 2nd cup are tilted and in contact with each other, or even if the igniter tube and 2nd cup are not in contact, the gas generating agent and charge transfer agent are not evenly charged. It may become. If the gas generating agent or transfer charge is unevenly loaded, abnormal combustion may occur when the inflator is ignited, and gas may not be generated as designed.

JP 2010-143270 A

  The problem to be solved by the present invention is that if the length of the parallel portion of the press-fit portion in the adapter is shortened in order to reduce the press-fitting load of the igniter tube and the 2nd cup to the adapter, the press-fitted igniter tube and 2nd cup It may be inclined.

  An object of the present invention is to suppress the tilt of the igniter tube and the 2nd cup that are press-fitted into the adapter as much as possible while reducing the press-fitting load of the igniter tube and the 2nd cup to the adapter.

In order to achieve the above object, the present invention provides:
An inflator for an airbag that generates gas for deploying an airbag,
Including a pressure vessel, an igniter, and a gas generating agent,
The pressure vessel has a base portion in which an adapter is joined to a base, and a diffuser portion that is joined to the base and has a gas ejection hole generated inside the inflator.
The igniter part has an igniter accommodated in an outer cylinder press-fitted into the adapter,
The gas generating agent is configured to be accommodated in a gas generating agent filling unit in the pressure vessel capable of ignition from the igniter unit,
In addition, the most important feature is that a multi-stage taper is formed in the press-fit portion of the adapter for press-fitting the outer cylinder.

  The present invention optimally sets the size of the multistage taper formed in the press-fit portion of the adapter for press-fitting the outer cylinder, even if the length of the parallel portion following the press-fit start portion of the press-fit portion is shortened. Thus, the centering accuracy of the outer cylinder press-fitted into the adapter can be improved.

  The said outer cylinder means the cylindrical member hold | maintained at the outer peripheral part of an adapter, such as an igniter tube and the 2nd cup of a dual type inflator.

  In the present invention, the taper formed in the press-fit portion of the adapter is multi-staged and the size thereof is set optimally, thereby suppressing an increase in the initial load during press-fit and reducing the length of the parallel portion to reduce the press-fit load. Even if it is made small, the centering accuracy of the outer cylinder to be press-fitted can be improved.

  And by improving the centering accuracy, the inclination of the outer cylinder after press-fitting can be prevented, the non-uniform loading of the gas generating agent and the transfer agent generated due to the inclination can be prevented, and abnormal combustion at the time of inflator ignition can be prevented.

It is the figure which showed the dual stage type inflator of this invention, (a) is a center longitudinal cross-sectional view, (b) is the A section enlarged view of (a), (c) is the B section enlarged view of (a), d) It is explanatory drawing of the multistage taper formed in the to-be-inserted part of an adapter. It is the figure which showed the single stage type inflator of this invention, (a) is a center longitudinal cross-sectional view, (b) is the C section enlarged view of (a). It is the figure which showed the conventional dual stage type inflator, (a) is a center longitudinal cross-sectional view, (b) is the D section enlarged view of (a), (c) is the E section enlarged view of (a).

  In the present invention, the press-fitting load of the igniter tube or 2nd cup to the adapter is reduced, and the purpose of suppressing the tilt of the igniter tube or 2nd cup press-fitted to the adapter as much as possible is formed in the pressed-in portion of the adapter. Realized by making the taper multi-stage.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a diagram showing a dual stage type inflator of the present invention having two igniters.

  The inflator 11 according to the present invention includes first and second igniter portions 3 and 4 in the pressure vessel 2 and first and second gas generating agents 5a that generate gas by ignition of the igniter portions 3 and 4. 5b and the filter 6 are accommodated.

  Among these, the pressure vessel 2 has a base part and a diffuser part joined to the base part. Of these, the base portion is configured by joining two adapters 2c and 2d to the base 2b, and the diffuser portion is configured by providing a gas ejection hole 2aa generated inside the inflator 11 on the side wall of the diffuser 2a. It is.

  The first igniter section 3 includes an igniter tube in which an igniter 3a installed in the one adapter 2c and a transfer charge 3b that instantaneously amplifies the ignition energy of the igniter 3a are press-fitted into the one adapter 2c. 7 is housed inside. The explosive charge 3b is inserted below the 1st cup 9 which is inserted into the igniter tube 7 from above the igniter tube 7 and has a communication hole 9a formed in the bottom wall.

  On the other hand, the second igniter section 4 includes a 2nd cup 8 comprising a cap 8a and a tube 8b in which a communication hole 8aa is formed in the side wall, in which an igniter 4a installed in the other adapter 2d is press-fitted into the other adapter 2d. It is the structure accommodated in the inside.

  The first and second gas generating agents 5a and 5b are accommodated in gas generating agent filling portions in the pressure vessel 2 that can ignite from the first and second igniter portions 3 and 4. Yes.

  Specifically, the second gas generating agent 5 b is charged in a second gas generating agent filling portion inside the 2nd cup 8. The first gas generating agent 5 a is inserted into the first gas generating agent filling portion inside the first cup 9 inserted above the igniter tube 7 and the outer peripheral portion of the second cup 8.

  A cushion member 10 is installed on the inside of the ceiling wall of the diffuser 2a in the first gas generating agent filling portion in order to prevent the first gas generating agent 5a from moving due to the vibration of the inflator 11 to prevent deformation or the like. Yes.

  In FIG. 1, the first taper 2cc, 2dc, for example, at the press-fitting start portion of the press-fitting portions 2cb, 2db of one adapter 2c for press-fitting the igniter tube 7 and the other adapter 2d for press-fitting the 2nd cup 8 Second tapers 2cd and 2dd are formed, respectively.

  Of the first taper 2cc, 2dc and the second taper 2cd, 2dd, the first taper 2cc, 2dc on the press-fitting start end side of the press-fit portion 2cb, 2db is, for example, the press-fit start of the press-fit portion 2cb, 2db. The angle θ between the end faces 2cba and 2dba is 45 ° or more.

  On the other hand, the angle ν of the second taper 2cd, 2dd continuous with the first taper 2cc, 2dc and the press-fitting start end surface 2cba, 2dba is larger than the first taper 2cc, 2dc, larger than θ, 90 °. It is as follows.

  That is, in the example of FIG. 1, the first tapers 2cc and 2dc are larger than the second tapers 2cd and 2dd.

  Thus, by increasing the size of the first taper 2cc, 2dc, it is possible to suppress the occurrence of galling or the like at the initial press-fitting of the igniter tube 7 or the 2nd cup 8 to the adapters 2c, 2d. An increase in load can be suppressed.

  On the other hand, by reducing the size of the second tapers 2cd and 2dd, the centering accuracy when the igniter tube 7 and the 2nd cup 8 are press-fitted into the adapters 2c and 2d is improved, and the inclination can be suppressed. Therefore, uneven loading of the gas generating agents 5a and 5b and the transfer powder 3b generated due to the inclination can be prevented, and abnormal combustion when the inflator 11 is ignited can be prevented.

  In the example of FIG. 1, the parallel portion 2ce is formed by forming the taper formed on the press-fitting start end side of the press-fit portions 2cb and 2db into two stages of the first taper 2cc and 2dc and the second taper 2cd and 2dd. , 2de, that is, the press-fitting length can be shortened to reduce the press-fitting load. As a result, the trouble of applying the lubricating oil to the parallel portions 2ce and 2de can be omitted.

  In the example of FIG. 1, the parallel portions 2ce and 2de following the press-fitting start portion and the second tapers 2cd and 2dd continuous with the parallel portions 2ce and 2de are connected by curved surfaces 2cf and 2df.

  As described above, when the second tapers 2cd and 2dd and the parallel portions 2ce and 2de are connected by the curved surfaces 2cf and 2df, the parallel portions 2ce and 2ce of the igniter tube 7 and the 2nd cup 8 from the second tapers 2cd and 2dd, respectively. The press-fitting into 2de can be performed more smoothly.

  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.

  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 example shown in FIG. 1, the taper formed at the press-fitting start portion of the press-fitted portions 2cb and 2db in the adapters 2c and 2d is two stages of the first taper 2cc and 2dc and the second taper 2cd and 2dd. However, it may be three or more stages.

  Even when the taper has three or more stages, it is desirable to reduce the taper in order from the press-fitting start end side of the press-fit portions 2cb and 2db in the adapters 2c and 2d toward the parallel portions 2ce and 2de.

  In the example shown in FIG. 1, no explosive charge is charged in the second igniter section 4, but the second igniter section 4 is also transmitted to the inside of the 2nd cup 8 as in the first igniter section 3. You may charge gunpowder. On the other hand, as long as the first gas generating agent 5 a can be ignited even without the transfer agent, the first igniter unit 3 may omit the transfer agent as with the second igniter unit 4.

  1 describes the dual-stage type inflator 11, the present invention can also be applied to the single-stage type inflator 21 shown in FIG. 2, the same reference numerals as those in FIG. 1 denote the same members, and detailed description thereof is omitted.

  The single stage type inflator 21 is obtained by omitting the other adapter 2d, the second igniter section 4, the second gas generating agent 5b, and the 2nd cap 8 in the dual stage type inflator 11 shown in FIG. .

  And one adapter 2c and the 1st igniter part 3 are arrange | positioned in the axial center part of the pressure vessel 2, and the 1st gas generating agent 5a is arrange | positioned in the outer peripheral part of the igniter tube 7 press-fit in one adapter 2c It is. In this case, the first gas generating agent 5a is ignited through the communication hole 7a formed in the side wall of the igniter tube 7.

  In the example shown in FIG. 2, not only between the retainer disk 22 fitted to the upper end of the igniter tube 7 and the first gas generating agent 5a, but also between the base 2b and the first gas generating agent 5a. A cushion member 10 is installed.

2 Pressure vessel 2a Diffuser 2aa Injection hole 2b Base 2c One adapter 2cb Press-fit portion 2cc First taper 2cd Second taper 2ce Parallel portion 2cf Curved surface 2d Other adapter 2db Press-fit portion 2dc First taper 2dd Second Taper 2de Parallel portion 2df Curved surface 3 First igniter portion 3a Igniter 4 Second igniter portion 4a Igniter 5a First gas generating agent 5b Second gas generating agent 6 Filter 7 Igniter tube 8 2nd cup 11 Inflator 21 Inflator

Claims (7)

An inflator for an airbag that generates gas for deploying an airbag,
Including a pressure vessel, an igniter, and a gas generating agent,
The pressure vessel has a base portion in which an adapter is joined to a base, and a diffuser portion that is joined to the base and has a gas ejection hole generated inside the inflator.
The igniter part has an igniter accommodated in an outer cylinder press-fitted into the adapter,
The gas generating agent is configured to be accommodated in a gas generating agent filling unit in the pressure vessel capable of ignition from the igniter unit,
And the inflator for airbags which formed the multistage taper in the to-be-inserted part of the said adapter which press-fits the said outer cylinder.   The airbag inflator according to claim 1, wherein the multi-stage taper is formed at a press-fitting start portion of the press-fitted portion.   3. The inflator for an air bag according to claim 1, wherein the multi-stage taper is such that a taper on a press-fitting start end side of the press-fitted part is larger than a taper on a parallel part side following the press-fitting start part. .   The inflator for an air bag according to any one of claims 1 to 3, wherein a parallel portion that follows the press-fitting start portion and a taper that is continuous with the parallel portion of the multi-stage taper are connected by a curved surface. .   The inflator for an air bag according to any one of claims 1 to 4, wherein the outer cylinder is an igniter tube.   The inflator for an air bag according to claim 5, wherein the outer cylinder is plural.   The inflator for an airbag according to any one of claims 1 to 6, wherein a filter is disposed along the inner surface of the side wall of the pressure vessel between the pressure vessel and the gas generant filling portion.

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