JP2000292099A - Squib and squib device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a squib and a squib device which can enhance the reliability in a performance of environmental resistance and can ensure performances for a long period. SOLUTION: This squib comprises a cup-shaped tubular body 2, ignition explosive 3 held in the tubular body 2 and ignited by heating by energizing, and a shaft-shaped plug 4 fitted in the tubular body 2 and constituted of resin sealing the ignition explosive 3. The tubular body 2 is formed in a stepped shape having a diameter enlarged on the opening 2a side, while the plug 4 is formed in a stepped shape corresponding to the shape of the inner periphery of the tubular body 2 and being in close contact with a portion over to the opening 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a squib used in a gas generator and a squib device.

[0002]

2. Description of the Related Art Seat belt pretensioners, airbags, and the like are known as devices for protecting an occupant from an impact generated at the time of an automobile collision. These pretensioners operate with a large amount of gas introduced from a gas generator to protect occupants. Further, the gas generator includes a squib (igniter) and a gas generating agent, and ignites the squib at the time of collision to ignite and burn the gas generating agent to rapidly generate a large amount of gas.

As an example of a squib used in a gas generator, as shown in FIG. 8, a cup-shaped tube 102 for accommodating an ignition agent 103, and a shaft inserted into the tube 102 and sealing the ignition agent 103 are provided. Embolus 104 is formed of plastic resin. The embolus 104 is provided with a pair of conductive pins 105 and 106 penetrating the embolus 104. Each of the conductive pins 105 and 106 is
An electric bridge line 107 protrudes inward and is electrically connected to a distal end. The electric bridge line 107 is the ignition ball 10 in contact with the
8 covered. The squib is mounted on a gas generator, and when a collision signal (energization) from a collision sensor is input to each of the conductive pins 105 and 106, the electric bridge wire 107 generates heat and ignites the ignition ball 108, and subsequently, The ignition charge 103 is ignited and burned. Then, the gas generating agent is ignited and burned by ejecting a flame or the like resulting from the combustion of the ignition agent 103 into the gas generator. In addition, squib (tube 102,
The embolus 104) is made of plastic resin because
This is in order to reduce the manufacturing cost as compared with the case where the embolus 104 is conventionally formed of glass or ceramics.

[0004]

In a conventional squib,
Since the opening side of the resin tube 102 is fitted into the tip of the resin plug 104 to seal the igniting agent 103 and the like, the reliability with respect to the environmental resistance is low, and the water between the tube and the plug is low. There is a possibility that air or air may enter and come into contact (leak) with the ignition charge 103 or the like. In an automotive environment, its performance must be guaranteed over a long service life of 15 years, but this cannot be achieved with conventional resin squibs.

[0005] The present invention provides a squib capable of increasing reliability with respect to environmental resistance performance and guaranteeing performance for a long period of time.
And a squib device.

[0006]

In the squib of the present invention,
It comprises a cup-shaped tube, an igniting agent housed in the tube and ignited by electric heating, and a shaft-shaped plug made of a resin inserted into the tube and sealing the igniting agent. And the embolus has a stepped shape corresponding to the inner peripheral shape of the tubular body and closely contacted over the opening. Thus, the area where the tube and the embolus come into close contact with each other is increased, and the sealing performance can be improved.

[0007] Further, the tubular body and the embolus are interposed with a sealing material,
Alternatively, it is preferable to improve the sealing property by applying an adhesive. Further, the tube is formed of resin or metal.

[0008] In the squib device of the present invention, a cup-shaped tube, an igniting agent housed in the tube and ignited by electric heating, and a shaft-shaped plug made of resin that is inserted into the tube and seals the igniting agent. A squib comprising a squib, a caulking projection, and a holder comprising a stepped mounting hole penetrating through the caulking projection, wherein the squib tube has a stepped shape for expanding the diameter at the opening side. And the embolus has a stepped shape corresponding to the inner peripheral shape of the tube and closely contacted over the opening,
The squib is inserted into the mounting hole from the embolus side, the opening side of the tube is mounted in the caulking protrusion, and the tip of the caulking protrusion is bent inward to caulk the stepped portion outside the tube. It is a structure that becomes. This can increase the close contact area and improve the sealing performance. In addition, by caulking the stepped portion outside the tubular body, the tightness between the tubular body and the embolus can be improved.

The squib has a pair of conductive pins penetrated and held by the embolus, and a bridge wire electrically connected to the tip of each conductive pin. The ignition agent is ignited, and the stepped portion outside the tubular body and located outside the embolus has a structure formed by caulking. Thus, the caulking force can be applied toward the opening side of the tubular body, and the action of bending the embolus can be reduced. Therefore, generation of a gap between each conductive pin and the tube can be reduced.

The open end of the tubular body and the plug are elastically contacted with a sealing material mounted on the step of the mounting hole.
Thus, not only the seal between the tube and the embolus but also the seal between the holder and the squib can be achieved with one seal material.

The tube is formed of resin or metal.
Further, the tube body is covered with a metal cup body to form a stepped double cylinder structure, thereby increasing strength and reducing deformation due to caulking.

When the gas generator is constituted by the holder and the cup, the squib can be easily mounted.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A squib and a squib device according to an embodiment of the present invention will be described with reference to the drawings.

The squib 1 shown in FIGS. 1 and 2 comprises a cup-shaped tube 2 and a shaft-shaped plug 4 formed of resin, and an igniting agent 3 housed in the tube 2. , A pair of conductive pins 5 and 6 and a bridge wire 7 for igniting the ignition charge 3.

The cup-shaped tube 2 is formed in a stepped shape whose diameter increases on the side of the opening 2a. For example, PBT (polybutylene terephthalate), PET (polyethylene terephthalate), PA6 (nylon 6), PA66 ( Nylon 6
6), PPS (polyphenylene sulfide), PPO
(Polyphenylene oxide) and other resins containing glass fibers (reinforcing material) and the like. This tube 2
A cylindrical cup body 11, a stepped portion 12 whose diameter is increased in a tapered shape from an opening of the cup body 11,
, And a cylindrical body 13 that is continuous with the inner surface. The thickness of the tube 2 is 0.5 to 2.5 mm
The strength is increased by the degree. Also cup body 1
An annular inner groove 14 is formed on the inner circumference of the cup body 1.
The bottom 1 (bottom 2b of the tube 2) has a thinned rupture portion 15. The rupture portion 15 ruptures due to an increase in the internal pressure of the tube 2 due to the ignition and combustion of the igniting agent 3, and causes the flame of the igniting agent 3 to be ejected to the outside. The opening end of the cylindrical body 13 (the end of the opening 2a of the tubular body 2) is formed to have a tapered shape from the outer periphery toward the inner periphery.

The igniting agent 3 is stored in the tube 2 on the side of the bottom 2b. Specific examples of the igniting agent 3 include those having zirconium (Zr), tungsten (W), and potassium perchlorate (KClO ₄ ) as components and using a fluororubber or nitrocellulose as a binder. In addition, in order to increase the contact area with the electric wire 7,
It is preferable to make it into a powdery or granular form.

The shaft-shaped embolus 4 is formed in a stepped shape that can be fitted in contact with the stepped shape on the inner periphery of the tube 2 and is made of, for example, a resin such as PBT, PA6, and PA66 and made of glass fiber (reinforced). Material) and the like. This embolus 4
Is molded, for example, by injecting a resin into a mold (mold), and at the time of this molding, by disposing the conductive pins 5, 6 in the mold, the conductive pins 5, 6 are integrally held. The embolus 4 is composed of a shaft body 16, a stepped portion 17 whose diameter is increased in a tapered shape from the end of the shaft body 16, and a flanged shaft body 18 continuous with the stepped portion 17. And that. The inner groove 1 of the tube 2 is provided on the outer periphery of the shaft 16.
4 are formed with projections 19 to be fitted. A stepped portion 21 is formed on the flange shaft 18 so as to taper toward the opposite side of the shaft 16, and a pair of rib claws 20 extend from the stepped portion 21. Each rib claw 20 is formed at an angle of 180 degrees from each other, and has a rib projection 22 on the outer periphery.

Each of the conductive pins 5 and 6 is held by an embolus 4. The conductive pins 5 and 6 are arranged side by side along the axis of the plug 4 and are electrically insulated by the resin of the plug 4.
Each of these conductive pins 5 and 6 extends from the tip of the shaft 16 to the inside of each rib claw 20 and penetrates the embolus 4. The conductive pins 5 and 6 are located at an angle of 90 degrees with respect to the rib claws 20. The shape of each of the conductive pins 5 and 6 is curved outward at the flange shaft 18 so as to lengthen the interface of the plug 4 with the resin (increase the contact area). The electric bridge line 7 is electrically connected to the ends of the conductive pins 5 and 6 on the shaft body 17 side. The electric bridge wire 7 generates heat by energizing the conductive pins 5 and 6 to ignite the ignition charge 3.

The squib 1 as described above is assembled, for example, by inserting the embolus 4 into the tube 2 from the railway bridge 7 side (the shaft 16 side). The tube 2 may be fitted outside the plug 4 and assembled, or the tube 2 and the plug 4 may be fitted together and assembled.

When the embolus 4 is inserted into the tube 2, the shaft 16
The outer circumference and the inner circumference of the cup body 11 and the outer circumference of the flange shaft body 18 and the inner circumference of the cylindrical body 13 are in contact with each other. When the stepped portion 17 of the embolus 4 comes into contact with the stepped portion 12 in the tubular body 2, the projection 1
The plug 9 and the inner groove 14 are fitted to each other to integrate the embolus 4 with the tube 2. Thus, the embolus 4 and the tube 2 are connected to the bottom 2 of the tube 2.
The sealing property is enhanced by the close contact from the b side to the opening 2a by increasing the contact area. Also, by inserting the embolus 4,
The electric bridge wire 7 and the igniting agent 3 are sealed in contact with each other, and the tapered shape of the stepped portion 21 of the plug 4 and the tapered shape of the opening 2a of the tube 2 are matched on the same inclined straight line a.

As described above, in the squib 1 of the present invention, the sealing property can be improved by increasing the contact area between the tube 2 and the plug 4. It is preferable that the contact area is 100 mm ² or more to improve the sealing property. Therefore, even if the squib 1 (tube 2, embolus 4) is made of resin,
Air and water do not enter the space between the embolic element 4 and the embolic element 4 and come into contact with the igniting agent 3 and the like (no leakage), the reliability with respect to environmental resistance performance can be enhanced, and a long service life can be achieved. Performance can be guaranteed over a wide range.

A conventional structure is employed in which the igniting agent 3 and the electric bridge wire 7 are brought into contact with each other, and the igniting agent 3 is made of powder or granules having zirconium (Zr) or the like as a component and having a powdery or granular form (see FIG. 8). )
Thus, it is not necessary to cover the electric bridge line with an ignition ball as described above, and the squib 1 can be provided at a low cost with a simple structure.

Further, current is supplied to each of the conductive pins 5 and 6 so that
Is generated, the ignition charge 3 can be ignited and burned only by this heat generation. Then, the internal pressure rises due to the combustion of the ignition charge 3,
The rupture portion 15 of the tube 2 is ruptured, and the flame of the igniting agent 3 is blown out. At this time, the pipe 2 has a thickness of 0.5 to
By setting it to 2.5 mm, the strength is increased and deformation is prevented.

As a structure for improving the sealing property between the tube 2 and the plug 4, an adhesive is applied between the inner periphery of the tube 2 and the outer periphery of the plug 4, and the inner periphery of the tube 2 and the plug 3 are sealed. 4, a sealing material 2 such as an O-ring or an annular packing as shown in FIG.
5 can be achieved. Thus, the squib 1 can further improve the sealing performance in combination with the increase in the contact area.

In order to increase the strength of the tube 2, a double cup structure made of resin and metal is provided by covering a metal cup 30 (a stepped shape whose diameter is increased at the opening 30a side) as shown in FIG. Is also good. In the bottom 30b of the cup body 30, an ejection hole 31 for ejecting the flame of the ignition charge 3 to the outside through the rupture portion 15 of the tube body 2 is formed. Thus, the tube 2 has a structure capable of withstanding the internal pressure rise due to the ignition and combustion of the ignition agent 3 with a margin. Further, the tube 2 may be formed in a cup shape using only metal such as stainless steel.

Next, the squib device 51 shown in FIGS.
Is composed of the squib 1 described above (see FIGS. 1 and 2) and a holder 52 on which the squib 1 is mounted.

The holder 52 comprises a holder main body 53 and a caulking projection 54 projecting from an end of the holder main body 53. The holder 52 has a mounting hole 55 which is opened at the end of the caulking projection 54 and whose diameter is reduced in two steps toward the holder main body 53. The mounting hole 55 communicates with a storage hole 56 opened at the end of the holder main body 53 (the side opposite to the caulking projection 54).

In order to assemble the squib device 51, the seal ring 57 is attached to the mounting hole 5 from the caulking projection 54 side.
5 and is mounted on the second step 58 on the storage hole 56 side. Subsequently, the squib 1 is inserted into the mounting hole 55 from the opening 2 a side (each rib claw 20 side) of the tube 2, and the mounting hole 5 is inserted.
The end of the opening 2a of the tube 2 is partially brought into contact with the first step portion 59 on the opening 5 side, so that the tube 2 is mounted in the holder 52. In this state, the squib 1 has the cylindrical body 13 of
5 and the end of the opening 2a of the tube 2 (tapered shape)
The stepped portion 21 (tapered shape) of the embolus 4 is elastically contacted with the seal ring 57. Also, each rib claw 20 of the embolus 4 penetrates the mounting hole 55, and together with the conductive pins 5 and 6, the storage hole 5
6 protrudes.

Subsequently, the stepped portion 12 outside the tubular body 2 is caulked by bending the tip of the caulking projection 54 radially inward (toward the squib 1). At this time, by adjusting the length of the caulking protrusion 54, the stepped portion 12 outside the tubular body 2
It is preferable to caulk the portion of the embolus 4 outside the flange shaft 18. With such a structure, the caulking force is applied to the tube 2
Can be acted toward the opening 2a side, and the effect of bending the embolus 4 can be reduced. Therefore, each conductive pin 5, 6
The resin of the embolus 4 is not peeled off from the space, so that a gap is not generated, and the intrusion of air or water can be reduced as much as possible. Further, since the resin is hardly peeled off due to the curved shape of the conductive pins 5 and 6, the generation of a gap due to the bending of the plug 4 can be reduced.

After the squib 1 is mounted on the holder 52 and caulked, the storage hole 5
The shorting clips 60 and the like are inserted into the inside of each of the pins 6, and the respective conductive pins 5 and 6 are short-circuited by the engagement of the respective rib claws 20 with the rib projections 22.

As described above, in the squib device 51 of the present invention, when the squib 1 is mounted on the holder 52 and the squib 1 is caulked, the structure of the squib 4 reduces the deformation of the plug 4.
The air and water do not enter the space between the resin 6 and the resin and do not come into contact with the igniting agent 3 (without leakage), the reliability of the environmental resistance can be improved, and the performance can be improved over a long service life. Can be guaranteed. The crimping can enhance the adhesion between the tube 2 and the embolus 4. In addition, the sealing property between the embolus 4 and each of the conductive pins 5 and 6 can be enhanced by the curved shape of each of the conductive pins 5 and 6. Further, the opening 2a of the tube 2 of the squib 1
And the stepped portion 21 of the embolus 4 is elastically contacted with the seal ring 57, so that the seal between the holder 52 and the squib 1 can be achieved by one seal ring 57.

The squib device 51 constitutes the gas generator G as shown in FIG. The gas generator G of FIG. 7 is for a seat belt pretensioner (not shown) of an automobile, and includes a squib device 51 and a metal cup body 62 into which a gas generating agent 61 is loaded. At the bottom of the cup body 62, a gas discharge hole 62a for discharging gas generated by combustion of the gas generating agent 61 to the outside is formed. The gas discharge hole 62a is closed by a thin burst plate 63 made of aluminum or the like. I have.

The gas generator G is assembled by inserting the holder 52 into the cup 62 from the squib 1 side. The opening side of the cup body 62 is fitted into the outside of the caulking projection 54 of the holder 52 and caulked by the holder body 53. The gas generator G energizes the conductive pins 5 and 6 of the squib 1 to ignite and burn the igniting charge 3 by the heat generated by the electric bridge wire 7 and ignites and burns the gas generating agent 61 by the flame from the squib 1. To generate a large amount of gas. Subsequently, a large amount of gas generated in the cup body 62 is burst plates 63, which are broken by the increase in the internal pressure of the cup body 62,
The gas is guided to the seat belt pretensioner through the gas discharge holes 62a. Thus, the seatbelt pretensioner is activated by the high-pressure gas to fasten the seatbelt.

As described above, even if the squib device 51 is applied to the gas generator G, the squib device 51 can guarantee environmental resistance and service life as described above.
It is possible to guarantee the performance of the squib 1 over a long period of one year. Therefore, even if the squib 1 (the tubular body 2 and the embolus 4) is made of resin, the squib 1 can endure the severe service life of the automobile.

The squib pig device 51 can be applied to a gas generator that deploys and inflates an airbag due to a collision of an automobile. This gas generator is for a driver's seat, a passenger's seat, or a side collision, and inflates and deploys an airbag by gas generated by burning a gas generating agent. The squib device 51 is mounted on a housing (cylindrical body) of the gas generator, and installs the squib 1 in the housing. A gas generating agent, a filter, and the like are arranged in the housing, and the squib 1 burns the gas generating agent via the transfer agent or directly by the flame to generate a large amount of gas for deploying and inflating the airbag.

[0036]

According to the squib of the present invention, the sealability can be improved by increasing the contact area between the cup-shaped tube and the axial emboli. Therefore, even if the tube and embolus constituting the squib are formed of resin, air and water do not enter the space between the tube and the embolus and come into contact with the igniting agent and the electric bridge. ), It is possible to increase the reliability for environmental resistance performance, and to guarantee the performance over a long service life.

The structure for improving the sealing property can be achieved by applying an adhesive between the tube and the plug, and by interposing a sealing material between the tube and the plug. is there.

In the squib device of the present invention, when the squib is mounted on the holder and caulked, the squib is caulked at the stepped portion outside the tube, so that the contact between the outer periphery of the embolus and the inner periphery of the tube can be improved. In particular, by caulking a step portion outside the tubular body and located at the outside of the embolus, a force that bends the embolus is reduced, and a gap is generated between the embolus and each conductive pin. Minimized. Therefore, even if the tube and the plug are formed of resin, air, water, and the like enter not only between the tube and the plug but also between the plug and each conductive pin and come into contact with the igniting agent and the electric bridge. No (leakage), reliability against environmental performance can be increased, and performance can be guaranteed over a long service life. When the squib device is applied to a gas generator, in a car environment,
It is possible to guarantee the performance of the squib over a long period of time.

[Brief description of the drawings]

FIG. 1 is an assembly view showing a squib.

FIG. 2 is an exploded view showing a squib.

FIG. 3 is a diagram showing a first modified example of a squib.

FIG. 4 is a view showing a second modification of the squib.

FIG. 5 is a view showing a squib device.

FIG. 6 is a view showing a squib device.

FIG. 7 is a diagram showing a gas generator to which the squib device is applied.

FIG. 8 is a view showing a conventional squib.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 squib 2 tube 3 igniting agent 4 plug 5, 6 conductive pin 7 electric bridge 25 seal material 51 squib device 52 holder 55 mounting hole 57 seal ring 58 second step

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Hori 3903-39, Tomimachi, Himeji-shi, Hyogo F-term in Himeji Plant of Nippon Kayaku Co., Ltd. 3D054 DD22 DD28 FF20

Claims (9)

[Claims] 1. A cup-shaped tube (2), an igniting agent (3) housed in the tube (2) and ignited by energized heating, inserted into the tube (2) An axial plug (4) made of a resin for sealing the igniting agent (3), wherein the tubular body (2) has a stepped shape whose diameter is enlarged on the side of the opening (2a); A squib in which the embolus (4) has a stepped shape corresponding to the inner peripheral shape of the tubular body (2) and closely contacted over the opening (2a). 2. The tube (2) and the embolus (4)
The squib according to claim 1, wherein the squib is in close contact with a sealing material (25) or by applying an adhesive. 3. The squib according to claim 1, wherein the tube (2) is made of resin or metal. 4. A cup-shaped tube (2) and said tube (2)
(3) which is stored inside and ignites when energized and heated
A squib (1) comprising: a tubular plug (4) fitted in the tube (2) and sealing the igniting agent (3); A squib device comprising: a holder (52) including a stepped mounting hole (55) penetrating the inside of the caulking projection (54), and a tube (2) of the squib (1). Has a stepped shape whose diameter is enlarged on the side of the opening (2a), and the embolus (4) has a stepped shape corresponding to the inner peripheral shape of the tubular body (2) and closely contacted over the opening (2a). At the same time, the squib (1) is inserted into the mounting hole (55) from the plug (4) side, and the opening (2a) of the tube (2) is inserted.
The crimping protrusion (54) is attached to the inside of the crimping protrusion (54), and the tip of the crimping protrusion (54) is bent radially inward to crimp the stepped portion (12) outside the tubular body (2). A squib device with a structure. 5. The squib (1) includes the emboli (4).
A pair of conductive pins (5, 6) that are penetrated and held, and a bridge wire (7) electrically connected to the tip of each of the conductive pins (5, 6). The electricity is supplied to 6) to generate heat in the electric bridge line (7) to generate the ignition charge (3).
The squib device according to claim 4, wherein a portion of the stepped portion (12) outside the tubular body (2) and located outside the embolus (4) is caulked. 6. The end of the opening (2a) of the tube (2) and the plug (4) are in elastic contact with a sealing material (57) mounted on a step (58) of the mounting hole (55). Claim 4
Or the squib device according to claim 5. 7. The squib device according to claim 4, wherein said tube (2) is formed of resin or metal. 8. The squib device according to claim 7, wherein said tube (2) has a stepped double cylinder structure covered with a metal cup body (30). 9. The gas generating agent (6), wherein the holder (52) is
Gas generator (G) with cup body (62) for loading 1)
The squib (1) is disposed in the cup body (62) by closing an open end of the cup body (62). Squib device.