JP2006347374A - Gas generator for air bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generator for an air bag with high damp-proof property. <P>SOLUTION: A first igniter collar 26 is pressed/fixed from above by a first support member 30. The first igniter collar 26 is calked at an outer side bottom surface 13b of a housing. The housing bottom surface 13a has a first annular groove 33 and a fixing material 34 is filled in the first annular groove 33. Since air-tight property of the housing 11 is high, the damp-proof property is excellent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air bag gas generator used in an automobile passenger restraint system.

  A pyrotechnic gas generator equipped with a gas generating agent that generates gas by combustion maintains the good ignitability of the gas generating agent, thereby improving the hermeticity of the housing and preventing moisture from entering inside. There is a need. In particular, for the igniter mounting portion of the housing, securing airtightness is an important issue for structural and mounting reasons.

Patent Document 1 discloses that a resin mold portion is formed and fixed between a metal collar and an initiator body by injection molding or the like. In this method, when the metal collar is fixed to the lower part of the housing, it is necessary to weld both in order to obtain hermeticity. In this case, it is necessary to increase the size of the metal collar in order to provide a function as a heat sink during welding so that the resin is not deformed by welding heat and the confidentiality is not impaired.
JP-A-4-334461 USP 5131679

  It is an object of the present invention to provide a gas generator for an air bag that does not require an increase in the size of a metal collar and is excellent in maintaining airtightness in a mounting portion between a housing and an ignition means.

As a means for solving the problems, the present invention
A gas for an airbag in which a combustion chamber is disposed in a housing having a gas discharge port, a gas generating agent for generating gas by combustion, and an ignition means for igniting and burning the gas generating agent are disposed in the combustion chamber. A generator,
The ignition means is a state in which the electric igniter and the igniter collar are integrated with a resin in a state where the electric igniter is disposed in a substantially cylindrical igniter collar,
The ignition means is in contact with the bottom surface of the housing on at least a partial surface of the igniter collar, and the bottom surface of the housing is formed by any one or two or more mounting structures selected from the following (1) to (3). A gas generator for an air bag is provided.
(1) The igniter collar is fixed by a support member having a flat surface portion and a cylindrical portion extending upward from the flat surface portion, and the flat surface portion is fixed to the bottom surface of the housing. The upper end surface of the igniter collar is pressed and fixed by the opening portion of the portion.
(2) The igniter collar is fixed by caulking the lower end portion to the outer surface of the bottom surface of the housing.
(3) A partial surface of the igniter collar that contacts the bottom surface of the housing has an annular groove, and the annular groove is filled with a fixing material.

  In the mounting structure (1), the igniter collar is pressed from above by the support member, whereby the contact surface between the igniter collar and the housing bottom surface and the airtightness of the contact surface between the igniter collar and the support member (that is, the housing (Inner airtightness) is improved. The support member is fixed to the bottom surface of the housing by welding at the flat portion. However, since welding only needs to be spot-welded at several places, the resin of the ignition means is not easily affected by heat during welding.

  The mounting structure (2) increases the airtightness inside the housing by increasing the adhesion between the igniter collar and the bottom surface (outer surface) of the housing. Since it is caulked, it is not necessary to fix it by welding.

  In the mounting structure (3), an annular groove is provided on a partial surface of the igniter collar, and a fixing material such as resin or rubber is filled in the annular groove (for example, an injection molding method or a coating method is applied). This enhances the airtightness inside the housing.

  Further, (4) the cylindrical portion of the support member may be pressed from above by a resin in which the electric igniter and the igniter collar are integrated. This attachment structure (4) improves the airtightness inside the housing by increasing the adhesion between the support member and the resin.

  The gas generator for an air bag of the present invention includes only one of (1), (2), and (3) mounting structure, (1) and (2), (2) and (3), (1 ) And (3), and a combination of all the mounting structures (1) to (3). In some cases, the mounting structure (4) can also be combined.

  Since the gas generator for an air bag of the present invention has high airtightness at the mounting portion between the housing and the ignition means and high moisture resistance inside the housing, it can maintain good ignitability of the gas generating agent for a long period of time.

  The embodiment will be described with reference to FIGS. FIG. 1 is a sectional view in the axial direction of a gas generator for an air bag according to the present invention, and FIG. 2 is a schematic view of a state in which a closure shell is removed from FIG. For ease of understanding, FIG. 1 is enlarged.

  The airbag gas generator 10 shown in FIG. 1 and FIG. 2 is of a dual type having two combustion chambers and two ignition means, but the present invention has one combustion chamber and one ignition means. The present invention can also be applied to a single type having the same. Further, it can be applied to a hybrid inflator that uses a gas generating agent and a pressurized gas in combination as an inflating means for an airbag, and an inflator that uses only a pressurized gas (such as a curtain inflator).

  In the gas generator 10 for an airbag, an outer shell is formed by a housing 11 in which a diffuser shell 12 and a closure shell 13 are joined and integrated. The diffuser shell 12 and the closure shell 13 are welded at the joint.

  A plurality of gas discharge ports 14 are provided on the peripheral surface of the diffuser shell 12, and the gas discharge ports 14 are closed from the inside with a seal tape 15 made of aluminum or stainless steel for moisture resistance.

  A first combustion chamber 20 and a second combustion chamber 40 are provided in the housing 11, and the second combustion chamber 40 is separated from the first combustion chamber 20 by a combustion chamber cup member 41.

  A cup member 21 is disposed in the first combustion chamber 20, and the internal space is a first ignition means chamber 22. An enhancer agent (not shown) and a first ignition means 24 are accommodated in the first ignition means chamber 22, and the first gas generating agent (not shown) is filled in the first combustion chamber 20. .

  A first through hole 23 is provided on the peripheral surface of the cup member 21 and is closed from the outside with a seal tape 24 made of aluminum or stainless steel in order to hold the enhancer agent.

  The first igniter 24 includes a first igniter 25 and a first igniter 25 in a state where a first electric igniter (first igniter) 25 is disposed in a substantially cylindrical metal first igniter collar 26. An igniter collar 26 is integrated by a resin 27. 28 is a conductive pin for connecting the connector.

  The first ignition means 24 is attached to the housing bottom surface 13a by the following four attachment structures.

Mounting structure (1)
The first support member 30 includes a flat portion 31 and a cylindrical portion 32 extending upward from the flat portion 31. The flat outer peripheral portion of the flat portion 31 is pressed from above and below by the coolant filter 65 and the housing bottom surface 13a, and is fixed to the housing bottom surface 13a by spot welding at the location indicated by X in FIG. Here, the outer peripheral portion of the front end of the flat portion 31 and the coolant filter 65 are in close contact with each other when the end surface of the coolant filter 65 is crushed. The opening of the cylindrical portion 32 has an inward flange portion 33. In the gas generator 10 for an airbag, since the first support member 30 and the second support member 50 are integrated, there are a total of five spot welding locations indicated by x. A structure in which the first support member 30 and the second support member 50 are separated may be employed.

  The first igniter collar 26 is surrounded by a cylindrical portion 32 of the first support member 30, and the outer surface of the first igniter collar 26 and the inner surface of the cylindrical portion 32 are in close contact with each other (first The outer diameter of the first igniter collar 26 is substantially equal to the inner diameter of the cylindrical portion 32), and the upper end surface 26a of the first igniter collar 26 is pressed from above by an inward flange portion 33.

  The cup member 21 is positioned by being fitted into the cylindrical portion 32, the bottom surface is in contact with the housing ceiling surface 12a, and the opening portion may be in contact with the flat portion 31, It does not need to be in contact.

  In this way, the first igniter collar 26 is pressed from above by the first support member 30, so that the contact surface between the first igniter collar 26 and the housing bottom surface 13 a and the first igniter collar 26 and the first The airtightness of the contact surface with the support member 30 (that is, the airtightness inside the housing 11) is improved. Further, since the first support member 30 only needs to be spot welded to the housing bottom surface 13a in the flat portion 31, the resin 27 is not easily affected by heat during welding.

Mounting structure (2)
The lower end surface of the first igniter collar 26 is fixed by being caulked to the outer bottom surface 13b side of the housing 11 (caulking portion 26b). For this reason, since it is not necessary to apply a welding method in order to fix the 1st igniter collar 26 to the housing bottom face 13a, the resin 27 is not influenced by welding heat.

Mounting structure (3)
A first annular groove 33 is provided on the surface where the first igniter collar 26 contacts the housing bottom surface 13a. The first annular groove 33 may not be partially continuous. The first annular groove 33 is filled with a fixing material 34 such as resin or rubber. The fixing material 34 is filled by an injection molding method or a coating method.

  In this way, by interposing the combination of the first annular groove 33 and the fixing material 34 between the first igniter collar 26 and the housing bottom surface 13a, the airtightness inside the housing 11 is improved.

Mounting structure (4)
The mounting structure (4) is related to the mounting structure (1), and the inward flange portion 33 of the first support member 30 is pressed from above by the projecting portion 27a of the resin 27 in the radial direction. In this way, by improving the adhesion between the first support member 30 and the resin 27, the hermeticity inside the housing 11 is enhanced.

  In the second combustion chamber 40, a second gas generating agent and a second ignition means chamber 44 (not shown) are accommodated. A second through hole 43 is provided on the peripheral surface of the combustion chamber cup member 41, and is closed from the outside with a seal tape 44 made of aluminum or stainless steel in order to hold the second gas generating agent.

  The second igniter 44 includes a second igniter 45 and a second igniter 45 in a state in which a second electric igniter (second igniter) 45 is disposed in a substantially cylindrical metal second igniter collar 46. An igniter collar 46 is integrated by a resin 47. Reference numeral 48 denotes a conductive pin for connecting the connector.

  The second ignition means 44 is attached to the housing bottom surface 13a in the same manner as the first ignition means 24 by the following four attachment structures.

Mounting structure (1)
The second support member 50 includes a flat part 51 and a cylindrical part 52 extending upward from the flat part 51. The flat portion 51 is pressed from above and below by the coolant filter 65 and the housing bottom surface 13a, and is fixed to the housing bottom surface 13a by spot welding at the location indicated by X in FIG. Here, the tip outer peripheral portion of the flat portion 51 and the coolant filter 65 are in close contact with each other when the end surface of the coolant filter 65 is crushed. The opening of the cylindrical portion 52 has an inward flange portion 53. In the gas generator 10 for an air bag, since the second support member 50 and the first support member 30 are integrated, there are a total of five spot welding locations indicated by x. A structure in which the second support member 50 and the first support member 30 are separated may be employed.

  The combustion chamber cup member 41 is positioned by being fitted into the cylindrical portion 52, the bottom surface is in contact with the housing ceiling surface 12 a, and the opening portion is in contact with the flat portion 51. However, it may not be in contact.

  Thus, by pressing the second igniter collar 46 from above by the second support member 50, the contact surface between the second igniter collar 46 and the housing bottom surface 13a, and the second igniter collar 46 and the second The airtightness of the contact surface with the support member 50 (that is, the airtightness inside the housing 11) is improved. Further, since the second support member 50 only needs to be spot-welded to the housing bottom surface 13a at the flat portion 51 at several places, the resin 47 is not easily affected by heat during welding.

Mounting structure (2)
The lower end surface of the second igniter collar 46 is fixed by being caulked to the outer bottom surface 13b side of the housing 11 (caulking portion 46b). For this reason, since it is not necessary to apply a welding method to fix the second igniter collar 46 to the housing bottom surface 13a, the resin 47 is not affected by the welding heat.

Mounting structure (3)
A second annular groove 53 is provided on the surface where the second igniter collar 46 contacts the housing bottom surface 13a. The second annular groove 53 may not be partially continuous. The first annular groove 53 is filled with a fixing material 54 such as resin or rubber. The fixing material 54 is filled by an injection molding method or a coating method.

  In this manner, by interposing the combination of the second annular groove 53 and the fixing material 54 between the second igniter collar 46 and the housing bottom surface 13a, the airtightness inside the housing 11 is improved.

Mounting structure (4)
The mounting structure (4) is related to the mounting structure (1), and the inward flange portion 53 of the second support member 50 is pressed from above by the protruding portion 47 a of the resin 47 in the radial direction. In this way, by improving the adhesion between the second support member 50 and the resin 47, the airtightness inside the housing 11 is enhanced.

(Other mounting structure)
Other mounting structures will be described with reference to FIGS. The bottom surface 13a of the closure shell 13 is provided with two holes used for fitting the first ignition means 24 and the second ignition means 44 and connecting the conductive pins 28 and 48 to a connector (not shown).

  The annular surface 17 of the hole for fitting the first ignition means 24 is provided with at least one L-shaped groove 18. On the other hand, a protrusion 29 b is provided on the surface 29 a of the first igniter collar 26 that contacts the annular surface 17.

  In FIG. 3B, when the first igniter collar 26 is fitted from top to bottom (in the direction of the arrow), the first igniter collar 26 is fitted after the projection 29b is fitted into the L-shaped groove 18. Is slightly rotated so that the protrusion 29b is positioned at the tip 18a of the groove 18. By doing so, rotation of the first igniter collar 26 is prevented, and the subsequent caulking work is facilitated.

  The protrusion height of the protrusion 29b is equal to or less than the depth of the L-shaped groove 18, and the formation position of the protrusion 29b is adjusted so that caulking work can be performed when the protrusion 29b is positioned at the tip end portion 18a. A similar mounting structure can be applied to the second ignition means 44 as well.

  A disc-shaped retainer 60 for adjusting the volume of the first combustion chamber 20 is fitted in the first combustion chamber 20 in accordance with the filling amount of the first gas generating agent. The retainer 60 has two holes, and these two holes are fitted into the cup member 21 and the combustion chamber cup member 41.

  A cylindrical coolant filter 65 having a function of filtering and cooling combustion gas is disposed outside the first combustion chamber 20, and between the outer peripheral surface of the coolant filter 65 and the gas discharge port 14 and the seal tape 15. A gap is provided.

  In the air bag gas generator 10, since the joint between the diffuser shell 12 and the closure shell 13 is welded, moisture does not enter and the gas outlet 14 is closed from the inside with a sealing tape. , Moisture will not invade. As described above, the mounting portion between the ignition means (the first ignition means 24 and the second ignition means 44) and the housing 11 having a complicated mounting structure and high possibility of moisture intrusion is provided in the mounting structures (1) to (1) to (2). (3) Or depending on the case, high airtightness is provided by the combination of the mounting structures (1) to (4).

  Therefore, when the gas generator for airbags of this invention is integrated in the passenger | crew restraint system of a motor vehicle, the inside of the housing 11 can maintain high moisture-proof property for ten years or more which is a lifetime of a motor vehicle.

  Next, the operation when the gas generator 10 for an air bag of FIG. 1 is applied to an air bag system of an automobile will be described. Below, the case where the 1st igniter 25 act | operates first and the 2nd igniter 45 act | operates behind is demonstrated.

  When the automobile collides and receives an impact, the operation signal is received from the control unit, and the first igniter 25 is activated and ignited to ignite and burn the enhancer agent. After that, the pressure in the ignition means chamber 22 increases, and the seal tape 24 that closes the first through hole 23 is destroyed, and combustion products (ignition energy) are released from the first through hole 23 into the first combustion chamber 20. Is done.

  Due to the release of the combustion products, the first gas generating agent is ignited and combusted to generate high-temperature combustion gas. The combustion gas is filtered and cooled through the coolant filter 65, then breaks the seal tape 15, is discharged from the gas discharge port 14, and inflates the airbag.

  The second igniter 45 is activated and ignited with a slight delay, and the second gas generating agent is ignited and burned to generate high-temperature combustion gas. Then, after being pressed by the high-temperature combustion gas, the seal tape 44 that closes the second through-hole 43 is broken, the combustion gas flows out from the second through-hole 43, is filtered and cooled through the coolant filter 65, The air is discharged from the gas discharge port 14 and further inflates the airbag.

The axial sectional view of the gas generator for airbags. The top view of FIG. 1 (however, the ceiling part is removed). Explanatory drawing when attaching an ignition means to a housing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas generator for airbags 11 Housing 14 Gas exhaust port 20 1st combustion chamber 24 1st ignition means 25 1st igniter 26 1st igniter collar 27 Resin 28 Conductive pin 30 1st support member 31 Planar part 32 Cylindrical shape Part 33 First annular groove 34 Fixing material

Claims (1)

A gas for an airbag in which a combustion chamber is disposed in a housing having a gas discharge port, a gas generating agent for generating gas by combustion, and an ignition means for igniting and burning the gas generating agent are disposed in the combustion chamber. A generator,
The ignition means is a state in which the electric igniter and the igniter collar are integrated with a resin in a state where the electric igniter is disposed in a substantially cylindrical igniter collar,
The ignition means is in contact with the bottom surface of the housing on at least a partial surface of the igniter collar, and the bottom surface of the housing is formed by any one or two or more mounting structures selected from the following (1) to (3). A gas generator for an air bag that is attached to the air bag.
(1) The igniter collar is fixed by a support member having a flat surface portion and a cylindrical portion extending upward from the flat surface portion, and the flat surface portion is fixed to the bottom surface of the housing. The upper end surface of the igniter collar is pressed and fixed by the opening portion of the portion.
(2) The igniter collar is fixed by caulking the lower end portion to the outer surface of the bottom surface of the housing.
(3) A partial surface of the igniter collar that contacts the bottom surface of the housing has an annular groove, and the annular groove is filled with a fixing material.

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