JP3009568U - Gas generator - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To eliminate the need for a gas generating agent sealed container, facilitate the drilling of gas holes that connect the ignition chamber and the gas generating chamber, and enhance the slag collection effect of the filter. A gas generator having a three-chamber structure is provided. A triple cylindrical container 31 having an inner cylinder 34, an intermediate cylinder 35, and an outer cylinder 36 is provided. An ignition chamber 38 is provided in the inner cylinder of the container 31, and a gas is provided between the inner cylinder and the intermediate cylinder. The generation chamber 39,
A first gas hole 4 that forms a filter chamber 40 between the intermediate cylinder and the outer cylinder, and connects the ignition chamber 38 and the gas generation chamber 39 to the inner cylinder 34.
5, the intermediate cylinder 35 has a second gas hole 46 communicating the gas generating chamber 39 and the filter chamber 40, and the outer cylinder 36 has a second gas hole 46.
0 is provided with a gas discharge hole 47 for communicating the outside with the inner cylinder 3
The gas generating chamber 39 defined by 4 and the intermediate cylinder 36 is a seal member 4 arranged in the first and second gas holes 45 and 46.
It is sealed at 8,49.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas generator used for an airbag, which is a safety device for automobiles.

[0002]

[Prior art]

 This type of conventional airbag gas generator is roughly classified into a tubular type mainly used for a passenger seat and a disk type mainly used for a driver's seat. Further, although there are various types such as a so-called three-chamber structure as the disc type, the one having a three-chamber structure has a characteristic that the structure is simple. A specific example of such a conventional gas generator having a three-chamber structure will be described with reference to FIG. 3 which is a cross-sectional view (see USP 4,547,342). In FIG. 3, this gas generator is equipped with a triple short cylindrical container 1 having an inner cylinder 4, an intermediate cylinder 5 and an outer cylinder 6, the container 1 having a bottomed cylindrical shape with one end open. It is formed by joining (7) the upper container 2 and the lid-like lower container 3 which is fitted to the upper container 2 by friction welding. The reason why the joint portion 7 is located at the end in this way is that the pressure contact burr mainly interferes with effective use of the space. Inside the container, an ignition chamber 8 is formed in the inner cylinder 4, a gas generation chamber 9 is formed between the inner cylinder 4 and the intermediate cylinder 5, and a filter chamber is formed between the intermediate cylinder 5 and the outer cylinder 6. A first gas hole 18, a middle gas cylinder 5 has a second gas hole 19, and an outer cylinder 6 has a gas discharge hole 21. A squib 11 and a transfer charge 12 connected to a collision sensor (not shown) are sequentially housed in the ignition chamber 8 in the axial direction, and these squib 11 and transfer charge 12 constitute an ignition means. A gas generating agent 13 and a cooling filter 14 are sequentially stored in the gas generating chamber 9 in the radial direction, and a deflector plate 15 and gas filters 22 and 16 are sequentially stored in the filter chamber 10. The deflector plate 15 has its upper end bent and abuts against the upper surface inside the container 1 to close it, and a gas hole 20 is opened at the lower end.

In this gas generator, when the collision sensor detects a vehicle collision, the squib 11 is electrically heated and ignited, whereby the transfer charge 12 is ignited. The hot air (arrow) of the transfer charge flows into the gas generating chamber 9 through the first gas holes 18, whereby the gas generating agent 13 reacts to generate a gas containing slag at a high temperature. Then, this gas passes through the cooling filter 14 and flows into the filter chamber 10 through the second gas hole 19 as shown by the arrow, hits the deflector plate 15 and goes downward, and passes through the gas hole 20 of the deflector plate 15. After ascending along the gas filter 22, the gas passes through the gas filters 22 and 16 and is cooled and slag is collected in the meantime to become a clean gas at an appropriate temperature, which is supplied from the gas release hole 21 into an airbag (not shown). To be done.

[0004]

[Problems to be solved by the device]

 By the way, in the case of the triple cylinder structure in which all the cylinder parts are frictionally pressure contacted like the above-mentioned gas generator, the processing of the upper first gas hole 18a bored in the inner cylinder 4 becomes a problem. That is, since the first gas hole 18a is inside the upper container 2, it is difficult to directly drill from the outside. On the other hand, although it is possible to perform it by electric discharge machining or the like, it is not realistic to adopt it due to cost, mass productivity, and the like. Therefore, if the first gas holes 18a are to be formed by drilling, which is an ordinary economical method, it is necessary to sequentially form the holes from the outside. On the other hand, from the viewpoint of effective use of the filter chamber space, the gas discharge hole 21 must be provided at the end of the filter chamber. Therefore, as shown in the figure, the gas discharge hole 21, the second gas hole 19, and the first gas hole 18a are located in a substantially straight line at the upper end of the container 1. In this case, the gas that flows out from the second gas hole 19 is first discharged straight from the gas discharge hole 21 and the gas filters 22 and 16 cannot be effectively used. 15 is provided so that the gas flowing out from the second gas hole 19 is once guided to the lower side of the filter chamber and then flows upward along the gas filter 22 so that the gas filters 22, 16 are effectively used. There is. Secondly, the second gas hole 19 and the first gas hole 18 a are arranged substantially symmetrically with respect to the center of the one-side cross section of the gas generating chamber 9 from the viewpoint of achieving uniform combustion of the gas generating agent. Since it is desirable, the first gas holes 18b are also provided in the lower portion of the gas generating chamber 9 to achieve uniform combustion of the gas generating agent 13. The first gas hole 18b can be formed by obliquely drilling inward from the tip of the intermediate cylindrical portion of the upper container 2. As described above, the gas generator has a problem that the deflector plate 15 is required in the filter chamber 10 and the upper and lower first gas holes 18a and 18b are required in the inner cylinder.

On the other hand, since the gas generating agent 13 has hygroscopicity, it is necessary to seal it from the outside air. Therefore, for example, in another type of gas generator in which the gas generating chamber is divided by a simple partition wall and is not sealed by a sealing member, the gas generating agent 13 can be broken by the hot air and the generated gas of the transfer charge 12. This is done by enclosing it in a sealed container made of thin metal. However, in the case of the above-mentioned gas generator, since the wall surface of the gas generating chamber 9 is sealed by friction welding, by attaching a thin aluminum foil (not shown) to the first and second gas holes 18 and 19. Since the gas generating agent 13 is sealed, the sealed container is unnecessary. Therefore, it is necessary to consider the sealing of the gas generating agent 13 when solving the above problems.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to eliminate the need for a hermetically sealed container for a gas generating agent and to provide an ignition chamber and a gas generating chamber. It is possible to enhance the slag trapping effect of the filter without the need for a deflector plate while maintaining a state where the gas holes communicating with the gas chamber can be easily drilled, and to connect the ignition chamber with the gas generating chamber. It is to provide a gas generator with a three-chamber structure that can optimize the position of.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a gas generator of the present invention is formed by joining one container member and the other container member that fits the container member, and has a triple tube having an inner cylinder, an intermediate cylinder and an outer cylinder. A cylindrical container is provided, in which an ignition chamber is formed in the inner cylinder, a gas generation chamber is formed between the inner cylinder and the intermediate cylinder, and a filter chamber is formed between the intermediate cylinder and the outer cylinder, and the ignition chamber is formed in the inner cylinder. A first gas hole communicating with the gas generating chamber, a second gas hole communicating with the gas generating chamber and the filter chamber in the intermediate cylinder, and a gas releasing hole communicating with the outside of the filter chamber in the outer cylinder, In a gas generator that stores an ignition means in the ignition chamber, a gas generating agent that reacts with the ignition means to generate gas in the gas generation chamber, and a filter that cools and collects slag in the filter chamber, The gas discharge hole is at an axial end of the filter chamber, and the second gas hole is the gas discharge hole. The first gas hole is provided at a position axially different from the second gas hole at the end portion of the gas generation chamber on the axially opposite side, and the gas generation chamber defined by the inner cylinder and the intermediate cylinder is It is hermetically sealed with a rupturable seal member arranged in the first and second gas holes.

Further, the inner cylinder and the intermediate cylinder are formed by welding the inner cylinder part and the intermediate cylinder part of both container members by welding, and the outer cylinder is formed by the outer cylinder parts of both container members via the sealing means. The joint portion of the intermediate cylinder is located between the second gas hole and the bottom surface of the container, and the joint portion of the seal structure of the outer cylinder is located near the center of the container from the joint portion of the intermediate cylinder. Located at a predetermined position, the second gas hole is provided obliquely toward the axially opposite end side of the gas generation chamber, and the first gas hole is on the extension line of the second gas hole in the oblique direction. It may be installed in the direction.

Further, the inner cylinder and the outer cylinder are formed by welding the inner cylinder part and the outer cylinder part of both container members, and the intermediate cylinder has a cylindrical partition wall member at each end of each container. It may be formed by being joined to the bottom surface of the member via a sealing means.

[0010]

[Action]

 Since the second gas hole and the gas discharge hole are located at the opposite axial ends of the filter chamber, the gas flowing out from the second gas hole flows in the axial direction, and the filter can be effectively used without the deflector plate. Therefore, the slag collecting effect can be enhanced. Further, the first gas hole and the second gas hole are provided at axially opposite positions, for example, at positions substantially symmetrical with respect to the center of one side cross section of the gas generating chamber, so that the combustion of the gas generating agent can be made uniform. It can be optimal. Further, in this case, since the gas generating chamber is sealed by the sealing member, a sealed container for the gas generating agent is not necessary, and as a joining means, for example, as shown in FIG. The first gas hole can be drilled by drilling from.

The inner cylinder and the intermediate cylinder are formed by welding the inner cylinder part and the intermediate cylinder part of both container members by welding, and the outer cylinder is formed by the outer cylinder parts of both container members via sealing means. The joining portion of the intermediate cylinder is located between the second gas hole and the bottom surface of the container, and the joining portion of the outer cylinder is located at a predetermined position near the center of the container from the joining portion of the intermediate cylinder. The second gas hole is obliquely provided toward the axially opposite end side of the gas generation chamber, and the first gas hole is provided in the extension cross section of the second gas hole and in the same direction. Since there is no restriction due to burrs on the outer cylinder part unlike the friction welding, it is possible to join the parts near the center.For this reason, tilt the drill from the tip of the outer cylinder part of one container member. The first gas hole can be provided.

In addition, the inner cylinder and the outer cylinder are formed by welding the inner cylinder part and the outer cylinder part of both container members, and the intermediate cylinder has a cylindrical partition wall member at each end of each container. If it is formed by being joined to the bottom surface of the member through the sealing means, the first gas hole is drilled through the gas release hole, and the second gas hole is provided in the partition member in advance. By arranging between the inner cylinder and the outer cylinder at the time of joining the container members, the above-mentioned desired gas hole arrangement can be easily obtained.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a sectional view of a gas generator according to a first embodiment of the present invention, and FIG. 2 is a sectional view of a gas generator according to a second embodiment of the present invention.

First, a first embodiment will be described with reference to FIG. First, the configuration will be described. In FIG. 1, the outer cylinder 36 is joined via an O-ring 50 (sealing means), and the arrangement and shape of the first gas hole 34 and the second gas hole 46 are mainly different from those in FIG. 3.

That is, in FIG. 1, a container 31 of a gas generator 30 of the present invention is formed by joining an upper container 32 having a cylindrical shape with a bottom and a lower container 33 having a lid shape, and an inner cylinder 34 and an intermediate cylinder. 35 is joined by friction welding, while the outer cylinder 36 is joined via an O-ring 50. That is, as shown in the figure, the outer cylindrical portion 36a of the upper container 32 and the outer cylindrical portion 36b of the lower container 33 are arranged in three stages so that when they are combined, a ring-shaped space 90 is formed in the central portion. A contact surface is formed. An O-ring 50 is fitted in the space 90 to seal the filter chamber 40 from the outside and prevent the generated gas from flowing out of an air bag (not shown). The joining 54 by the abutment can be performed without damaging the O-ring by appropriately setting the pressure contact stroke after the frictional heating during the frictional pressure contact between the inner cylinder 34 and the intermediate cylinder 35. For example, the O-ring 50 sandwiched between the upper container 32 and the lower container 33 is frictionally pressure-contacted so that the rotating side does not contact the O-ring. As described above, when the joining is performed through the O-ring 50, the filter chamber 40 is not narrowed by the pressure contact burr unlike the friction pressure contact, so that the position of the connection can be arbitrarily selected. The position of the joint 54 is a predetermined position near the center of the container 31, while the positions of the joints 52 and 53 of the inner cylinder 34 and the intermediate cylinder 35 are the lower end of the container 31. As described above, this position is set to a position where the outer cylinder portion 36a of the upper container 32 does not get in the way when the first and second gas holes 45, 46 are drilled from the outside.

Next, the second gas hole 49 is adjacent to the upper side of the joint portion 53 of the intermediate cylinder, the second gas hole is provided obliquely toward the upper side of the gas generation chamber 39, and the first gas hole 45 is provided. Is provided in the inner cylinder 34 above the gas generation chamber 39 in the extended cross section of the second gas hole 46 and in the same direction as the second gas hole 46. That is, as shown in the figure, the first gas hole 45 (diameter d1) is set so as to be located within the range of the cross section of the second gas hole 46 (diameter D1). As a result, the first gas hole 45 can be easily drilled from the outside. The first gas hole 45 is preferably arranged as symmetrical as possible with the second gas hole 46 with respect to the center of one side cross section of the gas generating chamber 39 from the viewpoint of uniform combustion of the gas generating agent 13. Also, thin aluminum tapes 48 and 49 are attached to the outlet side of the first gas hole 45 and the inlet side of the second gas hole 46, respectively. The gas generating agent 13 is sealed from the outside air by the aluminum tapes 48 and 49.

Further, in the gas generation chamber 39, in addition to the cooling filter 42 arranged on the peripheral wall surface on the outlet side, a cooling filter 41 also serving as a cushion is arranged on the bottom surface. Further, the filter chamber 40 is vertically divided by a partition member 55, and an intermediate filter 43 and a final filter 44 are arranged in each.

Next, the operation of the gas generator 30 will be described. The transfer charge 12 is ignited by the ignition of the squib 11, and the hot air (arrow) passes through the first gas holes, breaks the aluminum tape 48, and flows into the gas generation chamber 39. The gas generated by the reaction of the gas generating agent 13 breaks the aluminum tape 49 and flows into the lower part of the filter chamber 10, rises while passing through the intermediate filter 43 as shown by the arrow, and reaches the final filter 44 in the upper stage. After passing through this, the gas is discharged to the outside from the gas discharge hole 47. Here, since the first gas hole 45 and the second gas hole 46 are arranged in a shape close to point symmetry with respect to the center of the one side cross section of the gas generating chamber 39, the gas generating agent 13 is uniformly burned. In addition, since the second gas hole 46 is arranged on the opposite side in the axial direction of the gas discharge plan 47 and the container 31, the gas flow path of the filter chamber is lengthened and the slag collecting efficiency of the filter is improved.

Next, a second embodiment of the present invention will be described with reference to FIG. 2 is different from FIG. 1 in that the intermediate cylinder 65 is made of a partition member and is joined by seals 80 and 81, the outer cylinder 66 is joined by friction welding, and both the first gas hole and the second gas hole are horizontal. It is a point provided in the direction. That is, the container 61 of the gas generator 60 includes a double-cylindrical upper container 62 having an inner cylinder portion 64a and an outer cylinder portion 66a, and an inner cylinder portion 64b and an outer cylinder portion 66b each having a short cylindrical shape and fitted together. The lid-shaped lower container 63 is joined to each cylinder by friction welding 82, 83, and a cylindrical partition wall member 65 is fitted between the inner cylinder 64 and the outer cylinder 66. Collar-shaped contact surfaces 65a and 65b are formed at both ends of the partition wall member 65, and the contact surfaces 65a and 65b contact the bottom surfaces of the upper and lower containers 62 and 63 and are provided on the bottom surfaces. O-rings 80 and 81 are fitted in the recesses to seal between the gas generating chamber 69 and the filter chamber 70. The partition member 65 is positioned by a step portion 92 provided on the bottom surface of the upper container 62. A second gas hole 76 is provided below the partition wall member 65. This partition member 65 constitutes an intermediate cylinder.

The first gas hole 75 is provided in the upper part of the gas generation chamber 69. The first gas hole 75 (diameter d2) may be provided so as to be located within the range of the extended cross section of the gas discharge hole 77 (diameter D2) as shown in the figure, and the intermediate cylinder (partition) 65 before joining. In this case, it is possible to easily drill from the outside through the gas release hole 77. Further, in addition to this, it is also possible to diagonally drill from the tip of the outer cylindrical portion 66a to form an oblique shape. A cushion / cooling filter 71 is arranged below the gas generation chamber 69 so as to close the inlet of the second gas hole 76.

In this way, when the intermediate cylinder 65 is composed of the partition member, first, since there is no joint by friction welding as in the case of FIG. 1, the second gas hole 79 should be located at the end as much as possible. As a result, the gas flow path of the filter chamber 70 can be lengthened, and the slag collecting effect can be enhanced accordingly. Secondly, the drilling of the first gas hole 75 from the outside becomes easy. Further, since the gas generating chamber 69 is sealed by the O-rings 80 and 81, the gas generating agent 13 is sealed as in the case of FIG.

[0022]

[Effect of device]

 As described above, the gas generator of the present invention is a gas generator having a three-chamber structure, in which a gas release hole is provided at an axial end portion of the filter chamber, and a second gas hole communicating the gas generation chamber and the filter chamber is provided. A first gas hole that connects the ignition chamber and the gas generation chamber is provided at an axially opposite end of the gas generation chamber from a position opposite to the second gas hole in the axial direction. Since it is a rupturable seal, it does not require a sealed container for the gas generating agent, and while maintaining a state in which the gas holes that connect the ignition chamber and the gas generating chamber can be easily drilled, The slag collecting effect can be enhanced without the need for a deflector plate, and the position of the gas hole connecting the ignition chamber and the gas generation chamber can be optimized.

The inner cylinder and the intermediate cylinder are formed by welding the inner cylinder part and the outer cylinder part of both container members, and the outer cylinder is formed by the outer cylinder parts of both container members via the sealing means. The joint of the intermediate cylinder is located between the second gas hole and the bottom surface of the container, and the joint of the outer cylinder is located at a predetermined position near the center of the container from the joint of the intermediate cylinder. The second gas hole is provided obliquely toward the opposite end side in the axial direction of the gas generation chamber, and the first gas hole is provided in the extended cross section of the second gas hole and in the same direction. The first gas hole can be easily processed by inclining the drill from the tip of the outer cylinder of the container member.

The inner cylinder and the outer cylinder are formed by welding the inner cylinder part and the outer cylinder part of both container members, and the intermediate cylinder has a cylindrical partition wall member at each end of each container member. Assuming that it is formed by being joined to the bottom surface via a sealing means, the first gas hole is drilled through the gas release hole, the second gas hole is previously provided in the partition member, and both container parts are joined. The desired gas hole arrangement described above can be easily obtained by arranging it between the inner cylinder and the outer cylinder at times.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas generator according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a gas generator according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a conventional gas generator of a second embodiment.

[Explanation of symbols]

 11 Squib (Ignition Means) 12 Transfer Charge (Ignition Means) 13 Gas Generator 30 Gas Generator 31 Container 32 Upper Container (Container Member) 33 Lower Container (Container Member) 34 Inner Cylinder 35 Intermediate Cylinder 36 Outer Cylinder 38 Ignition Chamber 39 Gas generation chamber 40 Filter chamber 43 Intermediate filter 44 Final filter 45 First gas hole 46 Second gas hole 47 Gas discharge hole 48, 49 Aluminum tape (sealing member, metal foil) 50 O-ring (sealing means) 52 to 54 Joint part 60 Gas Generator 61 Container 62 Upper Container (Container Member) 63 Lower Container (Container Member) 64 Inner Cylinder 65 Partition Member, Intermediate Cylinder 66 Outer Cylinder 69 Gas Generation Chamber 70 Filter Chamber 75 First Gas Hole 76 Second Gas Hole 77 Gas release hole 80 O-ring (sealing means) 81 O-ring (sealing means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koji Tanaka 3903-39, Abundant Town, Himeji City, Hyogo Prefecture, Nihon Kayaku Co., Ltd., Himeji Factory, Sensor Technology Co., Ltd., Himeji Technical Center (72) Nobuaki Yokote 3903-39, Toyotomi-cho, Himeji-shi, Hyogo Nihon Kayaku Co., Ltd. Himeji Factory Sensor Technology Co., Ltd. Himeji Technical Center

Claims (3)

[Scope of utility model registration request] 1. A triple-layer cylindrical container formed by joining one container member and the other container member that fits the container member and having an inner cylinder, an intermediate cylinder, and an outer cylinder, wherein: An ignition chamber is formed in the inner cylinder, a gas generation chamber is formed between the inner cylinder and the intermediate cylinder, a filter chamber is formed between the middle cylinder and the outer cylinder, and the first cylinder is provided with a first gas hole that connects the ignition chamber and the gas generation chamber to each other. To
The intermediate cylinder is provided with a second gas hole communicating the gas generating chamber and the filter chamber, the outer cylinder is provided with a gas discharging hole communicating the filter chamber with the outside, the ignition chamber is provided with an ignition means, and the gas generation chamber is provided with the ignition means. A gas generating agent that reacts to generate a gas, in a gas generator that accommodates a filter that cools and slags the generated gas in a filter chamber, wherein the gas release hole is at the axial end of the filter chamber, Second
The gas hole is provided at an end of the gas generation chamber on the side opposite to the gas discharge hole in the axial direction, the first gas hole is provided at a position different from the second gas hole in the axial direction, and is defined by the inner cylinder and the intermediate cylinder. The gas generating chamber is sealed with a rupturable seal member arranged in the first and second gas holes. 2. The inner cylinder and the middle cylinder are formed by welding the inner cylinder part and the middle cylinder part of both container members by welding, and the outer cylinder is formed by the outer cylinder parts of both container members via sealing means. The joint portion of the intermediate cylinder is located between the second gas hole and the bottom surface of the container, and the joint portion of the outer cylinder is axially closer to the center of the container than the joint portion of the intermediate cylinder. Position, the second gas hole is obliquely provided toward the axially opposite end side of the gas generation chamber, and the first gas hole is provided on the diagonal extension line of the second gas hole and in the same direction. The gas generator according to claim 1, comprising: 3. The inner cylinder and the outer cylinder are formed by welding the inner cylinder part and the outer cylinder part of both container members, and the intermediate cylinder has a cylindrical partition wall member at each end of each container. The gas generator according to claim 1, which is formed by being joined to the bottom surface of the member via a sealing means.