JP2001124498A - Squib - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a squib which can guarantee the performance for years in use. SOLUTION: This squib is one where a plug 4 and two pieces of electrode pins 5 and 6 piercing the plug 4 are coupled (united) with each other by seal layer 8 for sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squib which can be used for a gas generator for operating a seat belt pretensioner or an airbag of an automobile.

[0002]

2. Description of the Related Art Seat belt pretensioners and airbags 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. This 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, there is a squib in which a tube containing an igniting agent and an embolus inserted into the tube and sealing the igniting agent are formed of a plastic resin. Further, the embolus is provided with an electrode pin made of two metal rods penetrating through the embolus. Each electrode pin protrudes into the tube, and a bridge is electrically connected to the tip. The Denbashi line is covered with an ignition ball in contact with the ignition charge.
The squib is mounted on a gas generator, and the electric bridge wire generates heat in response to a collision signal (energization) from a collision sensor, and the generated heat ignites an ignition ball, and then ignites and burns an ignition charge. Then, the gas generating agent is ignited and burned by the pressure and flame generated by the burning of the igniting agent.

[0004]

In a conventional squib,
Since the embolus is formed of plastic resin and each electrode pin is formed of a metal bar, due to its structure, there is no interface (interface) between the embolus (plastic resin) and each electrode pin (metal bar). No bonding (adhesion). Therefore, if deformation occurs due to a difference in thermal shrinkage (thermal expansion) between the plastic resin and the metal bar, the plastic resin of the plug may be peeled off from each electrode pin, and a gap may be generated. The generation of the gap causes water, air, and the like to enter (leak) into the pipe, and deteriorates the ignition agent, electric bridge, and the like sealed in the pipe.

It is an object of the present invention to provide a squib whose performance can be guaranteed over a long service life.

[0006]

A squib of the present invention (claim 1) comprises an embolus which is inserted into a tube and seals an explosive and an electric bridge, and an electrode pin which is connected to the electric bridge and penetrates through the embolus. The plug is formed of a resin, and a seal layer is formed between the plug and the electrode pin. Thereby, it is possible to prevent water, air, and the like from invading (leaking) into the tube from between the embolus and the electrode pin.

In the squib (claim 2) according to the present invention,
The sealing layer is adhered to the resin of the embolus and brought into close contact with the electrode pins. Thereby, the embolus and the electrode pin can be combined (integrated), and a gap between the embolus and each electrode pin can be eliminated due to a difference in thermal contraction (thermal expansion).

In the squib according to the present invention (claim 3),
By forming the sealing layer with a thermosetting adhesive, the gap between the embolus and the electrode pin can be reliably sealed with a simple and inexpensive structure.

In the squib according to the present invention (claim 4),
By using an epoxy resin that is generally used as the adhesive, the gap between the embolus and the electrode pin can be reliably formed at a lower cost.

[0010] Even when the squib (claim 5) according to the present invention is mounted on a gas generator and used, water or air can be prevented from entering (leaking) from between the embolus and each electrode pin. The performance of the generator can be guaranteed.

[0011] The gas generator according to the present invention (claim 6) comprises:
The squib of the present invention (claims 1 to 5) is mounted. Further, the seatbelt pretensioner and the airbag according to the present invention (claim 7) are provided with the gas generator (claim 6) according to the present invention.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A squib of the present invention will be described with reference to the drawings.

The squib 1 shown in FIGS. 1 and 2 includes a tube 2, an igniting agent 3, an embolus 4, two electrode pins 5, 6 and a bridge 7, and the tube 2 and the embolus 4 are made of resin. In this case, the cost is reduced. Also, Squib 1
Has a structure in which the embolus 4 and each of the electrode pins 5 and 6 are joined (integrated) by the seal layer 8 to enhance the sealing property therebetween.

The tube 2 of the squib 1 is formed in a cup shape for accommodating the ignition charge 3. The inner and outer peripheries of the tube 2 have a stepped shape by increasing the diameter of the opening 2a side with respect to the cup bottom 2b side. On the inner periphery of the tube 2, a cup bottom 2b
The annular groove 9 located on the side is formed, and the cup bottom 2 of the tube body 2 is formed.
b has a rupture portion 10 having a reduced thickness. or,
The end of the opening 2a of the tube 2 has a tapered shape 11 whose diameter decreases from the outer periphery toward the inner periphery. This tube 2 is made of PBT
(Polybutylene terephthalate), PET (polyethylene terephthalate), PA6 (nylon 6), PA66 (nylon 66), PPS (polyphenylene sulfide),
It is preferable to use a resin such as PPO (polyphenylene oxide) containing a reinforcing material such as glass fiber.

The igniting agent 3 is stored in the cup 2 on the side of the cup bottom 2b. As the ignition charge 3, zirconium (Zr), tungsten (W), potassium perchlorate (K
It is preferable to use a material having ClO ₄ ) as a component and using a fluororubber or nitrocellulose as a binder. Further, it is preferable that the igniting agent 3 is in the form of powder or granules in order to increase the contact with the electric bridge wire 7.

The embolus 4 is formed by a shaft 12 and a flange shaft 13 whose diameter is enlarged from the shaft 12 so as to form a stepped shaft closely contacting the inner peripheral shape (stepped shape) of the tube 2. I have. A protrusion 14 is formed on the outer periphery of the shaft 12 so as to fit into the annular groove 9 in the tube 2. Also, the flange shaft 13
Is formed with a tapered shape 15 whose diameter decreases toward the side opposite to the shaft body 12, and further has a pair of rib claws 16 extending continuously from the tapered shape 15. This embolus 4 is, for example, PBT, PET, PA6, PA66, PPS, PP
It is preferable to use a resin such as O containing a reinforcing material such as glass fiber.

The electrode pins 5 and 6 are arranged in parallel with the axis of the squib 1, penetrate through the embolus 4 from the tip of the shaft 12, and protrude inside the rib claws 16. Each of the electrode pins 5 and 6 has a shape 17 that is curved by the flange shaft 13 inside the embolus 4. Each of the electrode pins 5 and 6 is made of, for example, a conductive metal bar made of SUS stainless steel, iron / nickel alloy, or the like, and is formed of a resin of the plug 4 and a sealing layer 8.
Electrically insulated by Also, each electrode pin 5,
6 is preferably subjected to a gold plating treatment in order to make it excellent in corrosion resistance (moisture proof) and the like.

The electric bridge wire 7 is electrically connected to the electrode pins 5 and 6 exposed at the end of the shaft 12 by welding or the like. The electric bridge wire 7 generates heat when the electrode pins 5 and 6 are energized, and ignites and burns the igniting charge 3 in the tube 2 by the generated heat.

The sealing layer 8 includes the embolus 4 and each of the electrode pins 5, 5.
6 and is formed over the outer periphery of each of the electrode pins 5 and 6. The seal layer 8 is formed so as to penetrate the embolus 4 along the electrode pins 5 and 6 from the tip of the shaft body 12. As the seal layer 8, an adhesive excellent in bonding (integrating) resin and metal is used. As the adhesive that can be used in the present invention, those having a strong adhesive force with metal are good, and as a specific example,
Thermoplastic resins such as cellulose resin, alkyd resin, acrylic ester resin, polyamide resin, and polystyrene resin; thermosetting resins such as epoxy resin, cyanoacrylate resin, phenol resin, and melamine resin; and chemical plating agents such as triazine thiol. Can be.
Of these, preferred are thermosetting resins, and more preferred are epoxy resins. Thus, the sealing layer 8
Is adhered at the interface S1 between the resin of the embolus 4 and the resin by the adhesive, and adheres at the interface S2 between the electrode pins 5 and 6 with the metal bar material. Are bonded (integrated) to seal between them. Seal layer 8
May be formed in an annular shape between the embolus 4 and each of the electrode pins 5 and 6, but is formed over the entire area between the embolus 4 and each of the electrode pins 5 and 6 in order to enhance adhesion. Are preferred.

The bonding force (adhesive force) by the seal layer 8
I) The sealing layer 8 is separated from the plug 4 and the electrode pins 5 and 6 due to the difference in thermal contraction (or thermal expansion) between the resin of the plug 4 and the metal bar of each of the electrode pins 5 and 6. Ii) The sealing layer 8 does not peel off from the embolus 4 or each of the electrode pins 5 and 6 by the force acting when the squib 1 is attached (caulked) to the gas generator (see FIG. 6). It is assumed that the connection (integration) between the embolus 4 and each of the electrode pins 5, 6 can be maintained. Thus, a structure is provided in which the sealing property is improved without generating a gap between the embolus 4 and each of the electrode pins 5 and 6 due to heat shrinkage or the like.

The squib 1 configured as described above includes an embolus 4
Is inserted into the tube 2 from the shaft body 12 (electric bridge wire 7) side. Thus, the squib 1 has a structure in which the tubular body 2 and the plug 4 are in close contact with each other from the cup bottom 2b side of the tubular body 2 to the opening 2a, and seal the bridge 7 and the ignition charge 3 in a contact pressure state. The squib 1 generates heat by causing the electric bridge wire 7 to generate heat by energizing each of the electrode pins 5 and 6, so that the ignition charge 3
Ignites and burns. Then, by rupture of the rupture portion 10 of the tubular body 2 due to an increase in internal pressure due to combustion of the ignition charge 3,
The flame or the like of the ignition charge 3 is ejected to the outside (gas generator).

FIG. 3 shows a manufacturing procedure of the squib 1.
This will be described with reference to FIGS. Squib 1 is as follows
It is manufactured by performing the steps described. 3 to 5, the same reference numerals as those in FIGS. 1 and 2 indicate the same members.

Step of forming electrode pins 5 and 6: conductive metal bar 20 (stainless steel, iron / nickel alloy, etc.)
Are formed into a U-shape to form two parallel electrode pins 5 and 6. At this time, a curved shape 17 is also formed on each of the electrode pins 5 and 6 (see FIG. 3A). And
It is preferable to apply gold plating to the metal bar 20 to obtain the electrode pins 5 and 6 having excellent corrosion resistance (moisture proof) and the like.

Step of forming the seal layer 8: The metal bar 20 on which the electrode pins 5, 6 are formed is immersed in an adhesive from the U-shaped side 21 and pulled up, so that each of the electrode pins 5, 6 is formed.
Then, a seal layer 8 is formed (coated with an adhesive) (see FIG. 3B). At this time, the sealing layer 8 is formed on the entire opposite side of the metal bar 20 except for the tips of the electrode pins 5 and 6 on the side opposite to the U-shaped side 21. As a result, the sealing layer 8 comes into close contact with the interface S2 with the electrode pins 5 and 6 (see FIG. 3C). In addition, the sealing layer 8 injects an adhesive to each of the electrode pins 5 and 6,
Alternatively, it can be formed by coating.

Step of forming embolus 4 and connecting to electrode pins 5 and 6: Metal bar 20 on which seal layer 8 is formed
It is mounted in the split molds 22 and 23. Subsequently, the resin in a molten state is injected into each of the molds 22 and 23 to fill the space between the seal layers 8 of the electrode pins 5 and 6 and the outer periphery thereof. Thus, the injected resin comes into contact with the seal layer 8 and adheres at the interface S1 with the seal layer 8 by heat, molding pressure, and the like of the molten resin [see FIGS. 4A and 4B]. ]. As the resin, for example, PBT,
A resin made of a resin such as PET, PA6, PA66, PPS, or PPO containing a reinforcing material such as glass fiber is used. Then, the resin in each of the molds 22 and 23 and the seal layer 8 (adhesive) are thermally cured to form the embolus 4. In the process of thermosetting, the sealing layer 8 is bonded at the interfaces S1 and S2 between the resin of the plug 4 and the metal rods of the electrode pins 5 and 6.
The plugs 4 (resin) and the respective electrode pins 5 and 6 (metal rods) are joined (integrated) and sealed together. continue,
By peeling off the resin, the metal bar 20 and the like from the inside of each of the molds 22 and 23, a molded body composed of the electrode pins 5, 6 and the plug 4 is obtained (see FIG. 4C).

The components of the adhesive forming the seal layer 8 include:
The heat and molding pressure of the molten resin are appropriately selected. Thus, the bonding force (adhesive force) of the seal layer 8 is reduced by i) thermal contraction (thermal expansion) between the resin of the plug 4 and the metal rods of the electrode pins 5 and 6.
Ii) The squib 1 is connected to the gas generator [FIG.
See also], the sealing layer 8 is not peeled off from the embolus 4 or the electrode pins 5 and 6 by the force acting when the
It is assumed that the connection (integration) between the embolus 4 and each of the electrode pins 5, 6 can be maintained.

Step of connecting electric bridge line 7: metal bar 20
By cutting the U-shaped side 21, the respective electrode pins 5, 6 are separated and made independent. With this, each electrode pin 5, 6
Are composed of a single metal bar 20, respectively. [See FIG. 5 (a)]. Subsequently, the electric bridge wire 7 is electrically connected to each of the electrode pins 5 and 6 exposed at the end of the shaft body 12 by welding or the like (see FIG. 5B).

Step of assembling into squib 1: squib 1
Is assembled by inserting the embolus 4 into the tube 2 from the side of the shaft 12 (the electric bridge line 7). This is Squib 1
Has a structure in which the tube 2 and the embolus 4 are brought into close contact with each other from the cup bottom 2b side of the tube 2 to the opening 2a to seal the electric bridge wire 7 and the ignition charge 3 [see FIG. 5 (c)]. ]. In addition, tube 2
Is simultaneously or in advance with the above-described steps, for example,
It is formed of a resin such as PBT, PET, PA6, PA66, PPO, PPS or the like containing a reinforcing material such as glass fiber. In addition, the ignition charge 3 is also powdered or granulated in advance,
It is housed in the tube 2.

As described above, in the squib 1 of the present invention, the plug 4 and each of the electrode pins 5 and 6 are joined (integrated) by the seal layer 8, so that the gap due to the difference in thermal contraction (thermal expansion) is formed. It is possible to provide a structure that enhances the sealing performance without causing the generation. Therefore, even if the embolus 4 is formed of resin, water, air and the like can be prevented from entering (leaking) into the tube 2 from between the embolus 4 and each of the electrode pins 5 and 6, and thus the igniting agent can be prevented. 3 and the bridge line 7 are not deteriorated. When the seal layer 8 is made of a thermosetting adhesive, the plug 4 can be easily and inexpensively formed.
A structure that enhances the sealing performance between the electrode pins 5 and 6 can be adopted. In particular, when the sealing layer is made of a generally used epoxy resin, the embolus 4 is cheaper and surely.
And the electrode pins 5 and 6 can be sealed.

Next, a gas generator using the squib 1 of the present invention will be described.

The gas generator G shown in FIG. 6 is an example of operating a seat belt pretensioner of an automobile, and includes a squib 1, a holder 31 for mounting the squib 1, a gas generating agent 38, and a metal cup body 39. It is composed of

The holder 31 of the gas generator G comprises a holder body 32 and a caulking projection 33 projecting from the holder body 32. The holder 31 has a stepped mounting hole 34 which is opened at the end of the caulking projection 33 and whose diameter is reduced in two steps toward the holder body 32. The mounting hole 34 communicates with a storage hole 35 opened at the end of the holder main body 32 (the side opposite to the caulking projection 33). A gas generating agent 38 that generates gas by combustion is loaded in the cup body 39. The bottom 39b of the cup body 39 is formed with a gas discharge hole 39a for discharging gas generated by combustion of the gas generating agent 38 to the outside (seat belt pretensioner). The gas discharge holes 39a are closed by a burst plate 40 in the form of a thin film of aluminum or the like.

The squib 1 is connected to the opening 2a of the tube 2.
The tube 2 is inserted into the mounting hole 34 from the side, and the tapered shape 11 of the tubular body 2 is partially brought into contact with the first step portion 36 of the mounting hole 34, thereby mounting the inside of the holder 31. In this state, the squib 1 has a seal in which the opening 2 a side of the tube 2 is located in the mounting hole 34, and the tapered shape 11 of the tube 2 and the tapered shape 15 of the plug 4 are on the second step portion 37. It is elastically contacted with the ring 41. Each of the electrode pins 5 and 6 projects together with each of the rib claws 16 into the storage hole 35.

Subsequently, the stepped portion 2A of the tubular body 2 is caulked by bending the tip of the caulking projection 33 radially inward (toward the squib 1). At this time, it is preferable that the length of the caulking projection 33 be adjusted to caulk the portion of the stepped portion 2A of the tubular body 2 outside the flange shaft body 13 of the embolus 4. With such a structure, the caulking force can be applied to the opening 2a side of the tubular body 2, and the effect of bending the embolus 4 can be reduced. In addition, the curved shape 17 of each of the electrode pins 5 and 6 reduces bending of the embolus 4 due to caulking. Further, even if a caulking force acts on the squib 1, the bonding force (adhesive force) of the seal layer 8 causes
The sealing layer 8 is peeled off from the embolus 4 and each of the electrode pins 5 and 6,
There is no gap.

Then, the holder 31 is inserted into the cup body 39 from the squib 1 side, so that the gas generator G is assembled. The opening side of the cup body 39 is fitted outside the caulking projection 33 and caulked to the holder body 32.

The gas generator G energizes the electrode 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 the gas generating agent 38 by the flame from the squib 1. To ignite and generate a large amount of gas. Subsequently, a large amount of gas generated in the cup body 39 is released by the burst plate 4
0, is guided to the seat belt pretensioner through the gas discharge holes 39a. The seatbelt pretensioner is now activated by the high pressure gas and tightens the seatbelt.

As described above, when the squib 1 of the present invention is used for the gas generator G, even if a caulking force acts when the squib 1 is mounted on the holder 31, the embolus 4 and the respective electrode pins 5, 6 can be used.
The sealability can be maintained without generating a gap between them. Therefore, the performance of the gas generator G can be guaranteed over a long service life. The squib 1 can also be applied to a gas generator for inflating and deploying an airbag due to a collision of an automobile. There are gas generators for a driver's seat, a passenger's seat, and a side collision, and inflate and deploy an airbag by a large amount of gas generated by burning a gas generating agent. The squib 1 is mounted in a housing (cylindrical body) of the gas generator. In the housing, a gas generating agent, a filter, and the like are arranged, and the squib 1 burns the gas generating agent via a transfer agent or directly by the flame, thereby generating a large amount of gas for inflating and deploying the airbag.

When the squib 1 of the present invention, which is low in cost and has excellent durability, is mounted on a gas generator for activating a seatbelt pretensioner or an airbag, the ignition of the squib surely causes the gas in the gas generator to be released. By burning the generator, a large amount of gas can be generated. Therefore, the seat belt pretensioner and the airbag can be reliably operated by a large amount of gas from the gas generator.

[0039]

The squib of the present invention has a structure in which the seal is combined (integrated) with the embolus and the electrode pin by the seal layer to enhance the sealing property, so that the heat shrinkage (thermal expansion) between the embolus and the electrode pin is achieved. No gap is generated due to the difference between the two. Therefore, even if the embolus is formed of resin, it is possible to prevent water, air, and the like from entering (leaking) between the embolus and the electrode pin, thereby preventing deterioration of the igniting agent and the electric bridge in the pipe. . As a result, the performance of the squib can be guaranteed over a long service life.

When the sealing layer is formed of a thermosetting resin, a simple and inexpensive structure can seal the gap between the embolus and the electrode pin, and a low cost and excellent durability squib can be provided. By using a commonly used epoxy resin as the adhesive, it is possible to seal the gap between the embolus and the electrode pin at lower cost.

When a squib having a low cost and excellent durability is mounted on a gas generator, the performance of the gas generator itself can be guaranteed over a long service life.

When a squib having a low cost and excellent durability is mounted on a gas generator, and the gas generator is mounted on a seat belt pretensioner or an airbag, the squib is reliably fired, so that the gas inside the gas generator is reduced. A large amount of gas is generated by reliably burning the gas generating agent. And the seatbelt pretensioner and the airbag can be reliably operated by a large amount of gas from the gas generator.

[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 squib manufacturing procedure.

FIG. 4 is a diagram showing a procedure for manufacturing a squib.

FIG. 5 is a diagram showing a squib manufacturing procedure.

FIG. 6 is a diagram showing a specific example in which a squib is applied to a gas generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Squib 2 Tubular body 3 Igniter 4 Embolus 5 Electrode pin 6 Electrode pin 7 Electric bridge 8 Seal layer

Claims (7)

[Claims] 1. A squib comprising: an embolus inserted into a pipe body to seal an explosive and an electric bridge; and an electrode pin connected to the electric bridge and penetrating through the embolus. A squib characterized by being formed of a resin and having a seal layer formed between the embolus and the electrode pin. 2. The squib according to claim 1, wherein the sealing layer is adhered to the resin of the embolus and is in close contact with the electrode pin. 3. The squib according to claim 1, wherein the seal layer is formed of a thermosetting adhesive. 4. The squib according to claim 3, wherein said adhesive is an epoxy resin. 5. The squib according to claim 1, wherein the squib is mounted on a gas generator that operates a seatbelt pretensioner or an airbag. 6. A gas generator provided with the squib according to claim 1. Description: 7. A seat belt pretensioner, wherein the gas generator according to claim 6 is mounted.
Or an airbag.