JP2007314102A - Gas generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive pyro-type gas generator with simple structure. <P>SOLUTION: The gas generator 1 has a tubular housing 4, a partitioning member 9 which partitions the housing 4 into a combustion chamber 6 filled with a gas generating agent 5 for generating high temperature gas by combustion and a filter chamber 8 mounted with a filter medium 7, a holder 12 mounted at an edge portion 3 of the housing 4 and having an igniter 10 igniting and burning the gas generating agent 5 in the combustion chamber 6, a lid 14 mounted at an edge portion 15 of the housing 4 and holding the filter medium 7 together with the partitioning member 9, and a coil spring 2 with one edge in contact with the partitioning member 9. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas generator suitable for inflating a side airbag or the like, and more particularly to an inexpensive gas generator with a simple configuration.

  An air bag is known as one of safety devices for protecting an occupant from an impact generated when a car collides. This airbag operates with a large amount of high-temperature and high-pressure gas generated by a gas generator. Conventionally, a gas generator that can be filled with a gas generating agent and pressed and held with an appropriate force has already been disclosed (for example, Patent Document 1 below).

JP 2005-153873 A

  However, although there is no filter in the gas generator of Patent Document 1, a front wall is provided with a spring in order to securely hold the gas generating agent, and further, the unburned gas generating agent during combustion of the gas generating agent A combustion chamber wall capable of preventing outflow is provided, and the structure is complicated. In general, a hybrid type gas generator as disclosed in Patent Document 1 is more expensive than a pyro type gas generator.

  In order to solve these problems, the inventors of the present application made a prototype of the gas generator 30 shown in FIGS. 5 (a) and 5 (b). 5 (a) is an external view of the prototype gas generator, FIG. 5 (b) is a cross-sectional view taken along arrows (b)-(b) of FIG. 5 (a), and FIG. 5 (c) is FIG. 5 (a). It is a front view of the porous member arrange | positioned inside the gas generator made as prototype.

  Briefly, the gas generator 30 shown in FIG. 5A includes a cylindrical housing 34, and a combustion chamber 36 filled with a gas generating agent 35 that generates high-temperature gas by combustion in the housing 34. A holder having a filter chamber 38 to which the filter material 37 is mounted, a partition member 39 partitioned into the filter chamber 37, and an igniter 40 that is mounted on the end 33 of the housing 34 and ignites and burns the gas generating agent 35 in the combustion chamber 36. 42 and a lid portion 44 that is attached to the end portion 45 of the housing 34 and holds the filter material 37 together with the partition member 39. In addition, one end is in contact with the partition member 39, and in order to prevent the gas generating agent 35 from flowing into the filter chamber 38 due to a pressure increase in the combustion chamber 36 at the time of ignition, the diameter is larger than the size of the gas generating agent 35. The gas generating agent 35 in the combustion chamber 36 is held together with the porous member 51 in order to prevent the gas generating agent 35 from being pulverized due to vibration and the bowl-shaped porous member 51 having a plurality of small holes 51a at the bottom. Cushion material 52 (for example, made of foamed silicon or ceramic fiber).

  The housing 34 is filled with the lid portion 44, the filter member 37, the partition member 39, the porous member 51, the gas generating agent 35, and the cushion material 52 in this order from the other end 45, and the igniter 40 is fixed by caulking. The holder 42 is inserted. A gas discharge hole 41 is provided on the outer periphery of the cylindrical portion 50 between the partition member 39 and the other end portion 45 of the housing 34. Specifically, a plurality of gas discharge holes 41 are provided on the outer periphery of the cylindrical portion 50 forming the filter chamber 38 which is a position where no propulsive force is generated in the inflator when the gas is discharged. From these gas discharge holes 41, the high-temperature and high-pressure gas generated by the combustion of the gas generating agent 35 in the combustion chamber 36 passes through the porous member 51 and is attached to the combustion chamber 36 side of the hole 48. Is passed through a filter material 37 (cylindrical and has an internal space 49 inside) mounted in the filter chamber 38, cooled, filtered and discharged.

  However, there is a concern that the strength of the porous member 51 is insufficient when a gas generator is used in which the pressure in the combustion chamber is increased. In order to solve this, a member made of a high-strength material may be used, but such a material causes an increase in cost. Further, further weight reduction is demanded.

  Accordingly, an object of the present invention is to provide a gas generator that is lighter and cheaper than the conventional one by adopting a simple configuration.

Means and effects for solving the problems

  A gas generator according to the present invention includes a combustion chamber in which a gas generating agent that generates high-temperature gas by combustion is filled in a cylindrical housing, a cylindrical filter chamber having a gas discharge hole in a curved surface portion, and the combustion chamber And a partition member having a hole in the center, a cylindrical filter material mounted in the filter chamber, and an end of the housing, and igniting the gas generating agent in the combustion chamber A gas generator having an igniter for burning, wherein one end in the axial direction is installed around the hole of the partition member in the combustion chamber, and the winding interval in an uncompressed state Further has a winding spring smaller than the size of the gas generating agent.

  According to the above configuration, it is possible to prevent the unburned gas generating agent from flowing out into the filter chamber during combustion (preventing damage to the filter member) and to allow the generated gas to pass through the filter chamber by the winding spring. Moreover, since it becomes a simple structure using the above winding springs, it is possible to provide a pyro-type gas generator that is lighter and cheaper than the conventional one.

  In the gas generator of the present invention, it is preferable that the outer shape of the winding spring is a substantially truncated cone shape or a substantially hanging bell shape. With the above configuration, the gas generating agent can be easily held in the combustion chamber during assembly.

  In the gas generator of the present invention, it is preferable that the other end of the winding spring is a lid-like portion formed by winding a member forming the winding spring in a spiral shape. With the above configuration, it is possible to further prevent the unburned gas generating agent from entering the inside of the winding spring.

  The gas generator of the present invention is packed so that the winding interval from the other end of the winding spring to a predetermined position in the axial direction is in close contact, and the entire packed portion is substantially cylindrical. Is preferred. With the above configuration, when the winding spring is mounted and compressed in the combustion chamber, it is compressed almost in the axial direction, so that the shape of the winding spring does not collapse more than necessary and the winding interval does not increase. Therefore, the gas generating agent can be reliably held in the combustion chamber without being sandwiched between the winding springs.

  In the gas generator of the present invention, it is preferable that the winding spring is formed of a metal wire or a strip-shaped metal plate. By the said structure, the gas generator which has said each effect can be provided reliably.

Hereinafter, embodiments of a gas generator according to the present invention will be described with reference to the drawings.
FIG. 1 shows a sectional view of a gas generator 101 which is an example of an embodiment of a gas generator according to the present invention. In FIG. 1, a gas generator 1 includes a cylindrical housing 4, a combustion chamber 6 filled with a gas generating agent 5 that generates high-temperature gas by combustion, and a filter in which a filter material 7 is mounted. A partition member 9 that is divided into a chamber 8, a holder 12 that is attached to the end 3 of the housing 4 and ignites and burns the gas generating agent 5 in the combustion chamber 6, and an end 15 of the housing 4. And a lid 14 that holds the filter material 7 together with the partition member 9, and a winding spring 2 that is in contact with the partition member 9 at one end.

  The housing 4 is filled with the lid 14, the filter material 7, the partition member 9, the winding spring 2, and the gas generating agent 5 in this order from the other end 15, and the igniter 10 is caulked and fixed. 12 is inserted. The housing 4 is made of a metal such as iron, for example. A gas discharge hole 11 is provided on the outer periphery of the cylindrical portion 20 between the partition member 9 and the other end portion 15 of the housing 4. Specifically, a plurality of gas discharge holes 11 are provided on the outer periphery of the cylindrical portion 20 forming the filter chamber 8 which is a position where no propulsive force is generated in the inflator when gas is discharged. From these gas discharge holes 11, high-temperature and high-pressure gas generated by the combustion of the gas generating agent 5 in the combustion chamber 6 passes through the filter material 7 mounted in the filter chamber 8, and is cooled and filtered. Is done.

  The filter material 7 has a cylindrical shape having an internal space 19 formed by, for example, an assembly of knitted wire mesh, plain weave wire mesh, or crimp woven metal wire. In addition, one end of the filter material 7 is in contact with the inner plane portion of the lid portion 14, and the other end is in contact with a partition member 9 formed of metal or the like that defines the inside of the housing 4. Is held inside. Therefore, the internal space 19 is an elongated cylindrical space, and the generated gas can reach the surface of the lid portion 14.

  The partition member 9 has a flat disk shape having a hole 18. The partition member 9 is fixed in the housing 4 by caulking both the end 15 side and the end 3 side from the outer peripheral portion of the housing 4, and partitions the inside of the housing 4 into a filter chamber 8 and a combustion chamber 6. The filter is prevented from being damaged (melted) by the heat of combustion of the gas generating agent 5. The partition member 9 is made of, for example, stainless steel or iron. A seal member such as an aluminum tape is attached to one or both of the inner peripheral side of the housing 4 of the gas discharge hole 11 and the hole 18 of the partition member 9. In FIG. 1 which shows this embodiment, the case where the sealing member 16 stuck to the hole 18 is shown.

  The winding spring 2 is a spring that is formed by winding a metal wire such as a piano wire, a hard steel wire, a stainless steel wire or the like in a corrugated shape. In addition, as shown in FIG. 2, when not pressurized in the vertical direction (axial direction), the springs have a smaller interval than the gas generating agent 5, and the end 2a densely spirals the metal wire. It is a lid-shaped part formed by winding. In addition, as shown in FIG. 1, when it pressurizes by the predetermined value or more in the up-down direction (axial direction), it will shrink | contract and will become a substantially truncated-conical shape, and it will be in the state from which the space | interval of a winding and a winding was lost. . Therefore, as shown in FIG. 1, it is possible to prevent the gas spring 5 from being filled into the winding spring 2 when the gas generator 1 is completed. Thereby, the gas generating agent 5 is filled in the combustion chamber 6 other than the inside of the winding spring 2 and is held by the winding spring 2, the housing 4, and the holder 12 to suppress powdering due to vibration.

  The holder 12 holds the igniter 10 and is inserted into the end 3 of the housing 4, and is held by caulking together with the shaft end 13 of the housing 4, and closes the end 3 of the housing 4. Yes. As the igniter 10, it is preferable that the embolus is made of plastic or resin. This is because the cost can be reduced. Of course, it is also possible to use a conventional embolus formed of glass.

  The lid portion 14 is fitted into the end portion 15 of the housing 14, is held by caulking together with the shaft end portion 21 of the housing 4, and closes the end portion 15 of the housing 4.

  Next, the operation of the gas generator 1 will be described. When the collision sensor detects an automobile collision, the gas generator 1 sends a signal to the igniter 10 to ignite it. The flame of the igniter 10 is ejected into the combustion chamber 6 and the gas generating agent 5 is ignited and burned to generate high temperature gas. The ignition combustion of the gas generating agent 5 is sequentially shifted from the end 3 side of the housing 4 to the filter material 7 side. At this time, since the unburned gas generating agent 5 cannot pass through the gap between the winding springs 2, it does not pass through the holes 18 and enter the internal space 19 of the filter material 7. Therefore, damage to the filter material 7 can be prevented.

  When combustion in the combustion chamber 6 progresses and the combustion chamber 6 rises to a predetermined internal pressure, the high-temperature gas generated in the combustion chamber 6 passes through the holes 18 and flows into the filter material 7 where slag is produced. After collecting and cooling, it becomes a clean gas. This clean gas is discharged from the gas discharge hole 11.

  As a result, the sufficiently cooled clean gas discharged from the gas discharge hole 11 is directly introduced into the interior of the air belt, the air bag, etc., and instantly expands.

  According to the present embodiment, the winding spring 2 prevents the unburned gas generating agent 5 from flowing into the filter chamber 8 when the gas generator 1 is operated (preventing damage to the filter member 7), and the generated gas filter. Passing to the chamber 8 is possible. Moreover, since it becomes a simple structure using the above-described winding spring 2, the gas generator 1 can be provided which is lighter than the conventional one and is inexpensive.

  Further, since the end 2a of the winding spring 2 is a lid-like portion formed by winding a metal wire in a spiral shape, it is possible to further prevent the unburned gas generating agent 5 from entering the inside of the winding spring 2. it can. Further, since the outer shape of the winding spring 2 has a substantially truncated cone shape, the gas generating agent 5 can be easily held in the combustion chamber during assembly.

  The present invention can be modified in design without departing from the scope of the claims, and is not limited to the above embodiment. For example, it is possible to modify the winding spring 2 used in the gas generator 1 according to the present invention as follows.

  First, Modification 1 of the winding spring 2 used in the gas generator 1 according to the present invention will be described. FIG. 3 is a view showing a first modification of the winding spring used in the gas generator of FIG.

  As shown in FIG. 3, the winding spring 21 has a substantially hanging bell shape packed so that the winding interval from the end portion 21a to a predetermined position in the axial direction is substantially in close contact, and the packed portion (part 21b) The whole is substantially cylindrical. In addition, the other end 21a is a lid-like part formed by winding a metal wire densely in a spiral like the end 2a of the winding spring 2. Further, the interval between the lines other than the portion 21 b is the same as that of the winding spring 2. Further, like the end 2a of the winding spring 2, the end 21a is installed on the igniter 10 side.

  If the coil spring 21 having the above configuration is used in place of the coil spring 2 in the gas generator 1, the same effect as that of the gas generator 1 can be obtained, and the coil spring 21 is mounted in the combustion chamber 6 at the time of manufacture. When compressed, it is compressed almost in the axial direction, so that the shape of the winding spring 21 does not collapse more than necessary and the winding interval does not increase. Therefore, the gas generating agent 5 can be reliably held in the combustion chamber 6 without being sandwiched between the winding springs 21.

  Next, a second modification of the winding spring 2 used in the gas generator 1 according to the present invention will be described. FIG. 4 is a view showing a second modification of the winding spring used in the gas generator of FIG.

  As shown in FIG. 4, the winding spring 22 is a plate spring formed by winding a band-shaped metal plate. Examples of the strip-shaped metal plate include a hardened steel strip, a stainless steel strip, and a punch metal strip having a smaller hole than the gas generating agent 5. The distance between the plates is formed to be smaller than the gas generating agent 5. The end portion 22a is a lid-like portion formed by densely winding a band-shaped metal plate in a spiral shape. Further, like the end 2a of the winding spring 2, the end 22a is installed on the igniter 10 side.

  If the winding spring 22 having the above configuration is used instead of the winding spring 2 in the gas generator 1, the same effect as that of the winding spring 21 can be obtained.

It is sectional drawing of the gas generator which is an example of embodiment of the gas generator which concerns on this invention. FIG. 2 is a side view showing a normal time of a winding spring in the gas generator shown in FIG. It is a side view which shows the modification 1 of the winding spring used with the gas generator of FIG. It is a side view which shows the modification 2 of the winding spring used with the gas generator of FIG. (A) is an external view of a prototype gas generator, (b) is a cross-sectional view taken along (b)-(b) of (a), and (c) is disposed inside the prototype gas generator of (a). It is a front view of the porous member made.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,30 Gas generator 2,21,22 Winding spring 3,15,33,45 End part 4,34 Housing 5,35 Gas generating agent 6,36 Combustion chamber 7,37 Filter material 8,38 Filter chamber 9,39 Partition member 10, 40 Igniter 11, 41 Gas discharge hole 12, 42 Holder 13, 17, 43, 47 Shaft end portion 14, 44 Lid portion 16, 46 Seal member 18, 48 Hole 19, 49 Internal space 20, 50 Cylindrical Portion 51 Porous member 52 Cushion material

Claims (5)

A cylindrical housing is divided into a combustion chamber filled with a gas generating agent that generates a high-temperature gas by combustion, a cylindrical filter chamber having a gas discharge hole in a curved surface portion, and the combustion chamber and the filter chamber. A partition member having a hole in the center, a cylindrical filter material mounted in the filter chamber, and an igniter mounted on the end of the housing and igniting and burning the gas generating agent in the combustion chamber A gas generator comprising:
One end of the axial direction is installed around the hole of the partition member in the combustion chamber, and a winding spring is further provided in which the winding interval in the uncompressed state is smaller than the size of the gas generating agent. A gas generator characterized by comprising:   The gas generator according to claim 1, wherein an outer shape of the winding spring is a substantially truncated cone shape or a substantially hanging bell shape.   The gas generator according to claim 1 or 2, wherein the other end of the winding spring is a lid-like portion formed by winding a member forming the winding spring in a spiral shape.   4. The packing portion is packed so that a winding interval from the other end of the winding spring to a predetermined position in the axial direction is in close contact, and the entire packed portion is substantially cylindrical. The gas generator in any one of. The gas generator according to any one of claims 1 to 4, wherein the winding spring is formed of a metal wire or a band-shaped metal plate.

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