JP2602753Y2 - Gas generator for airbag - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator used for an airbag safety device for ensuring the safety of a driver and an occupant of an automobile from an impact caused by a collision of the automobile and the like. It relates to what is produced by welding.

[0002]

2. Description of the Related Art US Pat. No. 4,547,342 (Oct. 1) discloses a gas generator for an air bag using a friction welding container.
5, 1985) is known. The gas generator includes an upper container having a first inner cylindrical wall, a second inner cylindrical wall, an outer cylindrical wall having a gas discharge hole, and an upper lid,
The first inner cylindrical wall, the second inner cylindrical wall, the outer cylindrical wall, the lower container having the lower lid and the flange are connected to each other at the tips of the first inner cylindrical wall, the tips of the second inner cylindrical wall, and the tip of the outer cylindrical wall. The three inner portions are butt-welded and friction welded to define a central space in the first inner cylindrical wall, between the first inner cylindrical wall and the second inner cylindrical wall, and between the second inner cylindrical wall and the outer cylindrical wall. During the first
An annular space and a second annular space are defined, a transfer agent and an ignition means are stored in the central space, a gas generating agent is stored in the first annular space, and a cooling member and a filter member are stored in the second annular space. Is a gas generator for an airbag in which is stored.

At the time of friction welding, after necessary items are stored in each chamber, the upper container and the lower container are butted, one is fixed, and the other is pressed and rotated, and the butted portion is welded by friction heat. . This friction welding has manufacturing advantages that the welding time can be reduced and the heat energy source for welding can be reduced. However, the above-mentioned gas generating agent and transfer agent ignite when heated. Although friction welding can be performed at a relatively low temperature, the friction welding site is at a temperature higher than the ignition temperature.

[0004] Therefore, the gas generating agent in the first annular space is placed in a place avoiding the friction welding portion of the upper container, and a gap near the friction welding portion is a space in which nothing is stored. In addition, the transfer agent in the central space is put in the upper container, the ignition means is fixed in the lower container,
A gap is provided between the transfer agent and the ignition means, and the friction welding portion is positioned on the opposite side of the portion where the ignition means is fixed.

[0005]

Since the above-mentioned gas generator has three friction welding parts and is divided into three chambers, the space between the upper container and the lower container is subdivided. However, there is a problem that the storage space cannot be used effectively because the wall is in the way. In addition, since the gas generating agent and the transfer agent are separated from the friction welding portion, a large gap for storing nothing is generated, and from this viewpoint, there is a problem that the storage space cannot be used effectively.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to make use of an advantage in manufacturing of joining such as friction welding and to make the storage space as small as possible. An object of the present invention is to provide a gas generator for an air bag that can be used effectively.

[0007]

In order to achieve the above object, the gas generator for an air bag according to the present invention has an inner cylindrical wall (14).
And an outer cylindrical wall (13) and the inner and outer cylindrical walls (14, 1).
3) A top lid (4) extending between and into the inner cylindrical wall (14).
0), and an inner cylindrical wall (43).
And a lower container (12) having an outer cylindrical wall (42) and a lower lid (44) extending at least between the inner and outer cylindrical walls (43, 42). Are joined to form two joints (46, 47) by joining the two ends of the outer cylindrical wall (13, 42) with the tips of the outer cylindrical wall (13, 42). Are provided apart from the upper lid (40) of the upper container (11) and close to the lower lid (44) of the lower container (12). Near the upper end of the outer cylindrical wall (13), Multiple gas discharge holes (13A)
A plurality of gas holes (14B) are formed near the upper end of the inner cylindrical wall (14), and the inner cylindrical wall (14, 43) and the outer cylindrical wall (13, 42) are formed.
An annular space (49) defined between the upper and lower ends by the upper lid (40) and the lower lid (44), and the inner cylindrical wall (14, 43) has at least an upper end at the upper end. Top lid (4
0) having a central space (50) in which gas holes (1) in the inner cylindrical wall (14) are formed.
4B) and a igniter (35) for igniting the transfer agent (34) is disposed adjacent to and below the transfer agent (34). The annular space (49) contains a gas generating agent (36) around the inner cylindrical wall (14) in the vicinity of the gas hole (14B) of the inner cylindrical wall (14). The cooling / filter members (37A, 37B, 38) are arranged so as to surround the gas generating agent (36) in a space excluding the generating agent (36), and the gas flow from the gas generating agent (36) is temporarily reduced. After facing downward on the side of the lower lid (44), the gas release hole (1
Partition member (51) for turning upward toward 3A)
There are disposed, said partition member (51), wherein provided from the upper lid (40) to the middle that does not lead to the lower cover (44), wherein between lower cover (44) and the partition member (51),
Forming a gas passage (65) that opens over the entire circumference
One in which you composed. In the annular space (49), the partition member (51) defines a space for accommodating the gas generating agent (36) and a space for accommodating the cooling / filter members (37A, 37B, 38). Those that form are preferred. Further, it is preferable that an outer cylindrical wall (13) of the upper container (11) is provided with a mounting flange (41) for mounting an airbag.

The joining is made at two places 46, 47 between the tips of the inner cylindrical walls 14, 43 and between the tips of the outer cylindrical walls 13, 42.
Therefore, one of the walls is omitted as compared with the three-chamber structure, and the efficiency of the internal spaces 49 and 50 is increased. When the two joining portions 46 and 47 are brought closer to the lower lid 44 of the lower container 12, the gas generating agent 36 and the cooling member are placed in the annular space 49 between the inner cylindrical walls 14 and 43 and the outer cylindrical walls 13 and 42. And the filter members 37A, 37B, and 38 are collectively housed, and the cooling member 37A and the like are arranged at the joint portions 46, 47, and the gas generating agent 3 is provided at a portion away from the joint portions 46, 47.
6, the annular space 49 can be effectively used. Although the gas generating agent 36, the cooling member and the filter members 37A, 37B, 38 are collectively stored in the annular space 49, the gas flow from the gas generating agent 36 is once directed downward to the lower lid 44 side, and then the gas is discharged. The partition member 51 that turns upward toward the discharge hole 13A prevents the gas flow from flowing in a short-circuit manner. The gas passes through the gas passage 6
5 induces a downward flow that is substantially uniform over the entire circumference.
And passes through the gas passage 65 over the entire circumference.
Therefore, the cooling member and the local portions of the filter members 37B, 38
Use of the entirety of the
Slag can be collected and cooled effectively. The partition member 51 defines a space for storing the gas generating agent 36 and a space for storing the cooling / filter members 37A, 37B, and 38. Further, since the outer cylindrical wall 13 of the upper container 11 has the mounting flange 41 for mounting the airbag, the gas generator is mounted on the airbag with the upper container 11.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of the gas generator for an airbag according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.

The gas generator 10 has a cylindrical container appearance, and an upper container 11 and a lower container 12 form a container. The upper container 11 has a long outer cylindrical wall 1 on which a plurality of gas discharge holes 13A and a mounting flange 41 are formed.
3 and a long inner cylindrical wall 14 and an upper lid 40.
Extends in a disc shape between the outer cylindrical wall 13 and the inner cylindrical wall 14 and in the inner cylindrical wall 14. Each gas discharge hole 13A is formed near the upper end of the outer cylindrical wall 13, and the mounting flange 41 is provided on the opening side of the outer cylindrical wall 13. In the vicinity of the upper end of the inner cylindrical wall 14, a plurality of gas holes 14B communicating between the inner and outer cylindrical walls 14 are formed.

The lower container 12 has a short outer cylindrical wall 42, a short inner cylindrical wall 43, and a lower lid 44. The lower lid 44 has a ring plate shape between the outer cylindrical wall 42 and the inner cylindrical wall 43. And a hole 45 is formed in the inner cylindrical wall 43.

The tip of the inner cylindrical wall 14 of the upper container 11 and the tip of the inner cylindrical wall 43 of the lower container 12 are abutted against each other.
6 and the tip of the outer cylindrical wall 13 of the upper container 11 and the tip of the outer cylindrical wall 42 of the lower container 12
The upper container 11 is fixed, and the lower container 12 is rotated at a high speed while being pressed against the upper container 11.
8 is generated by friction welding. As a result, the inner cylindrical walls 14, 43, the outer cylindrical walls 13, 42, the upper lid 40, and the lower lid 44 form an annular space 49 in which the upper and lower ends are closed, and the inner cylindrical walls 14, 43, and the upper lid 40 define the annular space 49. , A central space 50 having an upper end closed and a lower end formed as a hole 45 is defined.

In the annular space 49, the gas generating agent 36 and the cooling screen 3 as a cooling member are provided in the following manner.
7A and 37B and a filter 38 are housed. That is, the annular space 49 is divided into upper and lower inside and outside a partition plate 51 provided in halfway that does not lead to the lower lid 4 4 from the upper cover 40, in close proximity to the gas holes 14B around the upper inner cylindrical wall 14 The gas generating agent 36 enclosed in the aluminum foil cup is stored, and a cooling screen 37A is stored below the gas generating agent 36. This partition member 51 is
Cooling screen 37A and outer inner cylinder between lid 44
Forming a gas passage 65 that communicates with the walls 13 and 42;
The gas passage 65 is open over the entire circumference.
In particular, the cooling screen 37A is located at the friction welding portions 46 and 47, and even if the high temperature burr 48 approaches, there is no danger of ignition because the cooling screen 37A is a metal wire mesh cooling screen. Further , the upper gas generating agent 3
The cooling screen 37B and the filter 38 are provided in the space between the partition 6 (partition plate 51) and the outer cylindrical wall 13 with the rectifying plate 53.
And is stored in a stacked state via the gas discharge holes 13A.

In the central space 50, the transfer agent 3 is provided in the following manner.
4 and the ignition means 35 are housed. That is, the transfer agent 34
Is enclosed in a container and arranged in the recess 20A of the housing 20, and a primer 33 is fitted into a bottom plate portion of the housing 20. The storage body 20 can be attached to the upper bottom of the concave portion 15 of the central space 50 by the following engaging means.
As shown in FIG. 2, circumferential notch teeth 14A are provided discontinuously on the inner periphery of the inner cylindrical wall 14 of the cylindrical container with a notch width L1 therebetween. The gas hole 14B is opened at the center of the notch width L1. A circumferential notch tooth 20B having a width L2 is provided on the outer periphery of the storage body 20 so as to be positioned above the circumferential notch tooth 14A (see FIG. 1). The width L2 is smaller than the width L1,
When the storage body 20 is rotated by the angle α as shown in FIG. 2, the circumferential cutout teeth 20B pass through the cutout width L1. In addition, a plurality of gas holes 20C are opened between the circumferential cutout teeth 20B. These gas holes 20C and the gas holes 14B are respectively provided with circumferential notch teeth 14A, 20B.
Are in the communicating position in a state in which. Further, as shown in FIG. 1, the circumferential notch teeth 20B of the storage body 20 are located on the upper side, and the circumferential notch teeth 14A of the inner cylindrical wall 14 are located on the lower side, and the state of FIG. The housing 20 is fixed to the gas generator 10. Thus, the transfer agent 34 is arranged close to the gas holes 20C and 14B so as to face the gas generating agent 36. In addition, 21 is a rotation stop, and 2
2 is a seal.

An ignition means 35 is accommodated in a lower portion of the concave portion 15 of the central space 50, and is fixed by a cover means (not shown) in a portion of the hole 45. The ignition means 35 is, for example, of a mechanical type. When a collision is detected, the ignition pin 60 is fired toward the primer 33. The ignition means is not limited to a mechanical type, and an electric detonator called a squib is well known. When this squib is used, the squib may be stored in the central space 50 instead of the squib 33 and the ignition means 35. Since the squib is small, the central space 50
May also be made small in accordance with the squib, and the hole 45 may be a hole through which the small squib passes.

Next, a manufacturing procedure of the gas generator 10 for an air bag having the above-described configuration will be described with reference to FIG. First, the upper and lower parts of the annular space 4 of the upper container 11 are reversed.
The gas generating agent 36, the cooling screens 37A and 37B as the cooling member, the filter 38, and the partition plate 51 are put in the portion 9 and the upper container 11 is fixed by the flange 41. At this time, the gas generating agent 36, the cooling screens 37A and 37B, the filter 38, and the partition plate 51 may be integrally assembled, and this assembly may be inserted into the annular space 49 of the upper container 11. Next, the lower container 12 is rotated at a high speed while being pressed against the upper container 11, and friction-welded at two butted portions 46 and 47. The burrs 48 of the friction welding are transmitted only to the cooling screen 37A and do not need to be separated much. During friction welding,
Whether or not the storage body 20 is attached to the upper container 11 is optional. Next, the ignition means 35 is inserted into the central space 50 to which the storage body 20 is attached, and is fixed with a screw cap (not shown) or the like. Because it is not intended to friction welding while accommodating the ignition means 35, the housing body 20 and the ignition means 35 can be housed in close contact.

Further, the operation of the gas generator 10 will be described with reference to FIG. When the collision is detected, the ignition pin 60 of the ignition means 35 hits the primer 33, the primer 33 explodes and the transfer agent 34 burns, and the hot air of the transfer agent 34 is released from the gas holes 14B, 2B.
After 0C, the gas is quickly jetted into the annular space 49. The cup 52 of the gas generating agent 36 is melted, and the gas generating agent 36 burns to generate nitrogen gas. The high-temperature nitrogen gas flows downward through the hole 52A of the partition plate 51 as shown by the arrow in the drawing, and once flows downward to the cooling screen 3 side.
7A, 37B, and then the partition plate 51,
The lower cover 44 and the like are turned upward toward the respective gas discharge holes 13A, flow therethrough, and the slag component is filtered by the filter 38, released from the respective gas discharge holes 13A, and the airbag (not shown) is deployed. At this time, the gas passes through the gas passage
65 induces a substantially uniform flow over the entire circumference.
And passes through the gas passage 65 substantially uniformly over the entire circumference in the circumferential direction.
It will flow into the cooling screen 37B.
The gas is now filled with the cooling screen 37B,
Flows almost uniformly (over the entire circumference)
Can cause local damage (such as heat melting) to them.
Slag collection and cooling are performed efficiently.

[0018]

The gas generator for an air bag according to the present invention has a structure in which the joining portion is formed in two places and the gas generating agent, the cooling member, the filter member, and the partition member are collectively stored in the annular space. Compared with the three-chamber structure, one of the walls is omitted, the use efficiency of the internal space is increased, and the size of the gas generator can be reduced. Then, for an annular space formed by bringing the two joining portions closer to the lower lid of the lower container, a cooling member such as a wire mesh is disposed at a portion of the lower container friction welding portion, and separated from the friction welding portion of the upper container. When a gas generating agent or a filter member is placed in the part, the gap for separating the gas generating agent from the friction welding site is reduced, the annular space is used effectively, and a hole in the central space where the ignition means can be inserted later Is formed, there is no gap between the transfer agent on the upper container side and the ignition means on the lower container side, and the size of the gas generator can be further reduced. The charging of the gas generating agent into the annular space of the upper container is performed by integrally assembling the gas generating agent, the cooling / filter member, and the partition member,
By mounting this assembly in the annular space, productivity can be improved by shortening the charging time of each member. Further, the partitioning member once directs the gas flow from the gas generating agent downward on the lower lid side, and then turns upward toward the gas discharge hole,
Since the short-circuit flow of the gas flow is less likely to occur, it is possible to prevent the adverse effect of putting the gas generating agent and the cooling / filter member together in the annular space. In addition, gas
Flow through the flow passage so that it is substantially uniform over the entire circumference.
Is induced, and passes through the gas passage along the entire circumferential direction.
The cooling member and the filter member
Efficient using all of them without the need for heat melting
Slag can be collected and cooled. When the partition member defines a space for accommodating the gas generating agent and a space for accommodating the cooling / filter member, the annular space is more effectively used. Further, when the gas generator is mounted on the upper container by the mounting flange of the upper container, even if the lower container is detached, the gas generator can fly only to the lower side, and has an effect of being safe.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a gas generator for an airbag according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

DESCRIPTION OF SYMBOLS 11 Upper container 12 Lower container 13 Outer cylindrical wall 14 Inner cylindrical wall 34 Transfer agent 35 Ignition means 36 Gas generating agent 37A, 37B Cooling screen (cooling member) 38 Filter (filter member) 40 Upper lid 42 Outer cylinder Wall 43 Inner cylindrical wall 44 Lower lid 46, 47 Butt (joining part) 49 Annular space 50 Central space 51 Partition plate (partition member)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshiyuki Kishino 2--11 Iwaya Minami-cho, Nada-ku, Kobe-shi, Hyogo Inside Sensor Technology Co., Ltd. (56) References US Patent 4547342 (US, A)

Claims (3)

(57) [Scope of request for utility model registration] An inner cylindrical wall (14) and an outer cylindrical wall (1).
An upper container (11) having an upper lid (40) extending between the inner and outer cylindrical walls (14, 13) and into the inner cylindrical wall (14); an inner cylindrical wall (43); A lower container (12) having a cylindrical wall (42) and a lower lid (44) extending at least between the inner and outer cylindrical walls (43, 42); And outer cylindrical wall (1
Joining two at the tips of 3, 42) to form two bonding sites (46, 47), both of said two bonding sites (46, 47) comprises on the container ( 11) Separate from the top lid (40) and lower container (12)
A plurality of gas discharge holes (13A) are formed near the upper end of the outer cylindrical wall (13), and the upper end of the inner cylindrical wall (14) is provided near the upper end of the outer cylindrical wall (13). A plurality of gas holes (14B) are formed near the inner cylindrical wall (14, 43) and the outer cylindrical wall (13, 4).
2) between the upper and lower ends of the upper lid (40) and the lower lid (4).
4) to form a central space (50) having the upper lid (40) at least at the upper end in the inner cylindrical wall (14, 43); In the space (50), a transfer agent (34) is arranged near the gas hole (14B) of the inner cylindrical wall (14), and an ignition means (35) for igniting the transfer agent (34). )
Is disposed below and adjacent to the transfer agent (34), and the inner cylindrical wall (14) is provided in the annular space (49).
A gas generating agent (36) is housed in the vicinity of the gas hole (14B) of the inner cylindrical wall (14), and the gas generating agent (36) is surrounded by a space excluding the gas generating agent (36). The cooling / filter members (37A, 37B, 38) are arranged as described above, and after the gas flow from the gas generating agent (36) is once directed downward on the lower lid (44) side, the gas discharge holes (13A ) partitioning member (51) to be deflected upward toward the are disposed, said partition member (51), provided from said upper lid (40) to the middle that does not lead to the lower cover (44), the partition A circumferential direction between the member (51) and the lower lid (44)
Do not form a gas passage (65) that opens over the entire circumference.
Gas generator for an air bag, characterized in that that. 2. The inside of the annular space (49) is divided by the partition member (51) into a space for accommodating the gas generating agent (36) and the cooling / filter members (37A, 37).
B, 38) and a space for accommodating the same.
The gas generator for an airbag according to claim 1. 3. An outer cylindrical wall (1) of said upper container (11).
The gas generator for an airbag according to claim 1 or 2, wherein the mounting flange (41) is provided in (3).