JP2002172996A - Igniter and fuse head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an igniter having a fuse head formed of ignition capacity reduction-less igniting powder with less content of lead compound. SOLUTION: This igniter S of a gas generator used for an air bag device for car comprise a cup-shaped tube body 10, a transfer charge 15 stored in the tube body 10, a plug 7, a bridge circuit line 5 heated by energization, and a fuse head 1 formed on the surface of the bridge circuit line 5. The fuse head 1 is formed in a double layer structure comprising a lead compound-containing first ignition powder layer 2 formed on the surface of the bridge circuit line 5 and a second ignition powder layer 3 free from a lead compound formed on the surface of the first ignition powder layer 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an igniter and an ignition ball, and more particularly to an igniter suitable for a gas generator used for an airbag device and a seatbelt pretensioner of an automobile, and an ignition ball used for these.

[0002]

2. Description of the Related Art Conventionally, an igniter mounted on a gas generator used for an airbag device or a seatbelt pretensioner of an automobile has been of an electric conduction type. This type of igniter converts electrical energy into heat energy on a bridge line, ignites an ignition ball formed of an igniting agent composed of a flammable composition near the bridge line, and by the flame, the transfer agent, The gas generating agent is burning. The ignition ball used in the electric energizing type igniter uses an ignition agent containing a large amount of a lead compound which ignites with high sensitivity.

In recent years, there has been a demand in the automobile industry for parts that use as little lead or lead compounds as possible in order to improve environmental and manufacturing safety. For this reason, it is desired to use a compound having a low lead content for an igniter used for an ignition ball.

[0004]

However, in the case of an igniter using an ignition ball made of an igniting agent having a low content of a lead compound, there is a problem that the ignition ability for reliably igniting the igniting agent is reduced. For this reason, when this type of igniter is used for an airbag device of an automobile or a gas generator of a seatbelt pretensioner, inflation and deployment may be delayed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ignition ball made of an igniting agent having a small lead compound content without lowering the ignition ability, and an igniter having the ignition ball.

[0006]

According to a first aspect of the present invention, there is provided an igniter, comprising: a cup-shaped tube; a transfer charge accommodated in the tube; an embolus; An igniter for a gas generator used in a vehicle airbag device or a seatbelt pretensioner, comprising an electric bridge line that generates heat when energized and an ignition ball formed on the surface of the electric bridge line, wherein the ignition ball A first igniting agent layer containing a lead compound formed on the surface of the electric bridge wire and a second igniting agent layer containing no lead compound formed on the surface of the first igniting agent layer It is characterized by having a structure. Forming a first pyrotechnic layer containing a lead compound on the surface of the bridge;
By forming a two-layer structure in which a second pyrotechnic layer containing no lead compound is formed on its surface, the high-sensitivity first pyrotechnic layer ignites when the electric bridge wire is energized, and the first pyrotechnic layer ignites. The second pyrotechnic layer, which has relatively low sensitivity, ignites. For this reason, even when the content of the lead compound in the igniting agent constituting the ignition ball is reduced, the ignition ability does not decrease.

The igniter according to a second aspect is the igniter according to the first aspect, wherein a coating layer is formed on a surface of the second igniting agent layer. Since the coating ball is provided on the surface of the second igniting agent layer of the two-layered igniting ball of the first and second igniting agent layers, each of the first and second igniting agent layers peels off. Disappears.

According to a third aspect of the present invention, in the igniter according to the first or second aspect, the first igniting agent layer uses trinitroresorcin lead as a fuel component, and the second igniting agent layer uses zirconium as a fuel. Component. A two-layer structure is formed in which a highly sensitive first igniting agent layer containing trinitroresorcin lead as a fuel component is formed on the surface of the electric bridge, and a second igniting agent layer containing zirconium as a fuel component is formed on the surface thereof. As a result, the high-sensitivity first igniting agent layer is ignited by energization of the electric wire, and the second igniting agent layer having relatively low sensitivity is ignited by the ignition of the first igniting agent layer. For this reason, even when the content of the lead compound in the igniting agent constituting the ignition ball is reduced, the ignition ability does not decrease.

According to a fourth aspect of the present invention, in the ignition ball, an electric bridge wire that generates heat by energization, a first igniting agent layer containing a lead compound formed on the surface of the electric bridge wire, and the first igniting agent layer With the second pyrotechnic layer containing no lead compound formed on the surface of
It has a layer structure. By forming a first pyrotechnic layer containing a lead compound on the surface of an electric bridge and forming a second pyrotechnic layer containing no lead compound on the surface, the first pyrotechnic layer has high sensitivity. The explosive layer ignites when the electric wire is energized, and the second igniter layer having relatively low sensitivity is ignited by the ignition of the first igniter layer. For this reason, even when the content of the lead compound in the igniting agent constituting the ignition ball is reduced, the ignition ability does not decrease.

[0010] According to a fifth aspect of the present invention, in the ignition ball according to the fourth aspect, a coating layer is formed on a surface of the second ignition charge layer. Since the coating ball is provided on the surface of the second igniting agent layer of the two-layered igniting ball of the first and second igniting agent layers, each of the first and second igniting agent layers peels off. Disappears.

According to a sixth aspect of the present invention, in the ignition ball according to the fourth or fifth aspect, the first igniting agent layer comprises trinitroresorcin lead as a fuel component, and the second igniting agent layer comprises zirconium as a fuel component. Is what you do. A two-layer structure is formed in which a highly sensitive first igniting agent layer containing trinitroresorcin lead as a fuel component is formed on the surface of the electric bridge, and a second igniting agent layer containing zirconium as a fuel component is formed on the surface thereof. As a result, the high-sensitivity first igniting agent layer is ignited by energization of the electric wire, and the second igniting agent layer having relatively low sensitivity is ignited by the ignition of the first igniting agent layer. For this reason, even when the content of the lead compound in the igniting agent constituting the ignition ball is reduced, the ignition ability does not decrease.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An igniter according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of an igniter S according to the present invention. In FIG. 1, an igniter S is disposed inside a cup body 8 shown by a two-dot chain line in the figure, and is used for a seat belt pretensioner of an automobile, an airbag device, and the like.

The igniter S is constituted by a tube 10 having a fitting cylindrical portion formed in a cup shape from a metal material such as stainless steel or aluminum. The opening side of the tube body 10 is formed in a stepped shape that expands in diameter with respect to the cup bottom 11, and a fire hole 12 that opens into the cup body 8 is formed in the cup bottom 11. At the open end of the tube 10,
A flange 13 is formed as a projecting portion that projects to the inside of the stepped portion 9 of the cup body 8. The flange 13 is in contact with the inside of the stepped portion 9 of the cup body 8, and
The above defines a combustion chamber for the gas generating agent P. The cup member 14 of the igniter S is inserted into the tube 10, and the ignition port 12 is closed by the cup member 14. or,
The transfer charge 15 in the cup material 14 is stored in the tube 10.

The embolus 7 includes an embolus body 17 and an embolus body 17.
And a shaft body 16 that is reduced in diameter in two steps and fitted into the opening side in the tube body 10 to form a stepped shape. The embolus main body 17 is formed with a plug mounting hole 19 that opens on the opposite side to the shaft body 16. The distal end side of the shaft body 16 is inserted into the cup material 14. At the tip of the shaft 16, a mounting groove 21 is formed for fitting the projection 20 on the opening side of the cup material 14. As the embolus 7, for example, a resin such as polybutylene terephthalate, polyethylene terephthalate, nylon 6, nylon 66, polyphenylene sulfide, polyphenylene oxide, or the like containing glass fibers is injected into a mold (not shown). To form.

The embolus 7 is provided with each electrode pin 2 of the igniter S.
2 and the reinforcing member 26 are integrally provided. Each of the electrode pins 22 and the reinforcing material 26 are integrated with the resin of the embolus 7 by insert molding when injecting the resin into the mold.

Each of the electrode pins 22 is arranged in parallel with the axis of the embolus 7 and passes through the shaft 16 of the embolus 7. Each of the electrode pins 22 is curved in the shaft 16, and protrudes into the mounting hole 19 of the embolus body 17 and the cup material 14. Each of the electrode pins 22 is formed of a conductive material such as stainless steel, iron / nickel alloy, or the like, and is electrically insulated by the resin of the plug 7. Further, the electric bridge wire 5 is welded to the electrode portion 22 to the steel portion 6 at the tip of the electrode pin 22 by welding or the like in the cup material 14.

The ignition ball 1 is, for example, as shown in FIG.
It has a two-layer structure of a first igniting agent layer 2 formed on the surface of the electric bridge wire 5 made of a nichrome wire and a second igniting agent layer 3 formed on the surface of the first igniting agent layer 2. . Further, a coating layer 4 is formed on the surface of the second ignition charge layer 3.

The first igniting agent constituting the first igniting agent layer 2 is:
It is mainly composed of a lead compound and an oxidizing agent component and a reducing agent component used as required. Examples of the lead compound that can be used in the present invention include lead oxides such as lead trinitroresorcin, lead thiocyanate, and lead (trilead tetroxide), and lead chromate. Of these, lead trinitroresorcinol is preferred. And, the first pyrotechnic layer 2
Dipping a mixed solution obtained by adding a binder obtained by dissolving the first ignition powder in a solvent to a predetermined thickness a predetermined number of times,
It is obtained by applying it to the surface of the bridge 5, drying and solidifying it. The first pyrotechnic charge layer 2 preferably covers the entire area of the electric wire 5.

The oxidizing agent component is used when, for example, lead trinitroresorcinol or lead thiocyanate is used as a lead compound, or for adjusting oxygen balance as an ignition agent. For example, potassium nitrate, sodium nitrate, potassium chlorate, potassium perchlorate and the like are preferable, and potassium perchlorate is particularly preferable.

The reducing agent component is used when a lead compound such as lead oxide or lead chromate is used, or for adjusting the oxygen balance as an ignition agent. For example, metals such as silicon, silicon iron, boron and zirconium can be exemplified.

Ethyl acetate, acetone, isoamyl acetate and the like are used as the solvent. Examples of the binder that can be used include nitrocellulose, carboxymethylcellulose and viton rubber, and the use of viton rubber is preferred.

Here, as a preferable composition of the lead trinitroresorcin, the oxidizing agent component and the solvent, 30 to 80 parts by mass, preferably 40 to 70 parts by mass of the lead trinitroresorcinol, and 20 to 70 parts by mass of the oxidizing agent component. Parts, preferably 30
６０60 parts by mass, the solvent is 50-150 parts by mass, preferably 80-120 parts by mass.

The second igniting agent layer 3 comprises a composition containing at least one selected from the group consisting of phosphorus, sulfur, zirconium, iron, tungsten, silicon and aluminum, more preferably zirconium as a fuel component. I do. Potassium nitrate, sodium nitrate,
Potassium chlorate, potassium perchlorate and the like are preferable, and more preferably, dipping is performed a predetermined number of times in a mixed solution obtained by adding the same solvent and a dissolved binder as used for the potassium perchlorate and the first ignition charge layer 2. Then, it is obtained by applying an arbitrary thickness to the surface of the dried and solidified first ignition charge layer 2 and drying and solidifying it.

When zirconium is used as the fuel component of the second igniting agent layer 3, for example, a preferable oxidizing component for zirconium is potassium perchlorate, and 35 to 75 parts by mass of zirconium, preferably 45 to 75 parts by mass.
It is preferable to mix 25 to 65 parts by mass, preferably 35 to 55 parts by mass of potassium perchlorate with respect to 65 parts by mass. To this, 80 to 120 parts by mass of a solvent is added, and 10 parts by mass of a dissolved binder is further added, and the dried and solidified surface of the first ignition charge layer 2 is applied by an arbitrary method,
After drying and solidifying, the second igniting agent layer 3 is formed.

After the second pyrotechnic layer 3 has dried and solidified,
Apply vinyl acetate resin etc. to the surface using a solvent,
The coating layer 4 is formed. This coating layer 4 prevents the first igniting agent layer 2 and the second igniting agent layer 3 from peeling off from the surface of the bridge wire 5. As described above, a highly sensitive material containing a lead compound is used for the first igniting layer 2 in contact with the electric bridge wire 5, and the surface thereof is covered with the second igniting agent layer 3 containing no lead compound. By using the ignition ball 1, the lead compound content in the entire ignition charge layer can be reduced while maintaining the ignition ability. The thicknesses of the first igniting agent layer 2 and the second igniting agent layer 3 can be appropriately adjusted so as to obtain desired ignition performance.
Preferably, the first pyrotechnic layer 2 is 0.1 to 2 mm,
The thickness of the second igniting agent layer 3 is preferably determined in the range of 0.2 to 4 mm.

Returning to FIG. 1, the reinforcing member 26 is made of stainless steel,
A cylindrical body 25 made of a metal material such as SPCC or a reinforced plastic made of a thermosetting resin or the like and serving as a projecting portion.
And the ring-shaped plate 24 are formed in a cup shape.
The cylindrical body 25 protrudes from the outer periphery of the embolus body 17, and extends from the flange 13 side of the tube body 10 to the opening side of the mounting hole 19 along the outer periphery of the embolus body 17. Ring-shaped plate 24
Are located between the embolus main body 17 and the shaft body 16 and are arranged in a direction orthogonal to the electrode pins 22. The ring-shaped plate 24 is partially exposed from the plug 7 on the outer peripheral side, and is integrated in the resin of the plug 7 on the inner peripheral side. The portion of the ring-shaped plate 24 partially exposed from the plug 7 constitutes a projecting portion together with the cylindrical body 25. The reinforcing material 26 allows the respective electrode pins 22 to pass through the inner peripheral hole 27 of the ring-shaped plate 24.

The gas generator of the present invention configured as described above is manufactured, for example, by the following procedure.

First, the embolus 7 is formed of resin,
Simultaneously with this molding, each electrode pin 22 and the reinforcing material 26 of the igniter S are insert-molded to be integrally provided with the resin of the plug 7. Subsequently, the bridge wire 5 is welded between the steel portions 6 at the tips of the electrode pins 22 of the embolus 7. This Denbashi Line 5
The first igniting agent 2, the second igniting agent layer 3, and the coating layer 4 are respectively coated on the surface of the substrate by dipping, dried, and solidified to form the ignition ball 1. The igniter S is integrated with the plug 7 by fitting the shaft 16 of the plug 7 on which the ignition ball 1 is formed into the cup material 14 containing the transfer charge 15.

Subsequently, a seal ring 28 is mounted on the reinforcing member 26 of the embolus 7. The seal ring 28 is disposed on the outer peripheral side of the cylindrical body 25 of the auxiliary member 26. Then, the plug 7 is fitted into the tube 10 from the cup material 14 side of the igniter S. At this time, the cup material 14 is placed on the cup bottom 1 of the tube 10.
1 until it comes into contact with the squib 1
2 is closed. Also, the shaft 16 of the embolus 7 is fitted into the opening side of the tube 10 and is fitted until it comes into contact with the stepped portion 29 of the tube 10, so that the flange 13 of the tube 10 is connected to the ring-shaped plate 24. And the seal ring 28. Thus, the tube 10 is assembled to the embolus 7.

Subsequently, the embolus 7 to which the tube 10 is attached is fitted into the cup body 8 from the cup member 14 side of the igniter S, thereby assembling the gas generator. At this time, the cylindrical member 25 of the reinforcing member 26 is fitted into the opening side in the cup body 8, and the plug 7 is fitted until the flange 13 of the tube body 10 contacts the inside of the stepped portion 9 of the cup body 8. Thus, the tube 10 and the cup material 14 of the igniter S are arranged inside the cup body 8, and the tube 10 and the cup body 8 define a combustion chamber. or,
The flange 13 of the tube 10 is placed between the stepped portion 9 of the cup body 8 and the ring-shaped plate 24. That is, from the cup bottom side of the cup body 8, the stepped portion 9 of the cup body 8, the flange 13 of the tube body 2, and the ring-shaped plate body 24 are arranged in this order, and these members 9, 13, and 24 contact each other. Will be in contact with you.

In this state, the open end side of the cup body 8 is bent toward the plug 7, and the bent portion 30 and the stepped portion 9 are caulked toward the cylindrical body 25 of the reinforcing member 26.
As a result, the stepped portion 9 and the flange 13 of the tube 10 are pressed against the ring-shaped plate 24 by the caulking force, and the seal ring 28 is also deformed, so that the cup body 8, the tube 10, and the ring-shaped plate are deformed. The body 24 is sealed between each other. That is,
The embolus 7 is sealed between the cup body 8 and the tube 10 by the ring-shaped plate 24. At this time, even if a force due to caulking acts on the plug 7 from the flange 13 of the tube 10, the deformation of the plug 7 is restricted by the ring-shaped plate 24 of the reinforcing member 26.

In the gas generator of the present invention, when the electrode pins 22 of the igniter S are energized, the highly sensitive first igniting agent layer 2 containing a lead compound is ignited by the heat generated by the electric bridge wire 5, and subsequently, The second pyrotechnic layer 3 ignites. Thus, transfer charge 1
Ignite 5. A flame caused by the ignition of the igniter S is jetted into the cup body 8, and the flame ignites and burns the gas generating agent P to generate a large amount of gas, which is introduced into the seat belt pretensioner. The seatbelt pretensioner is now activated by the high pressure gas and tightens the seatbelt.

As described above, the igniter S according to the present invention comprises:
More preferably, it is used by being mounted in a gas generator used for a seat belt pretensioner or the like. And
A first igniting agent layer 2 which is a highly sensitive igniting agent layer containing a lead compound therein, and has a lower sensitivity than the first igniting agent layer 2,
The ignition ball 1 has a two-layer structure with a second igniting agent layer 3 containing no lead compound. The ignition ball 1 having a two-layer structure can reduce the lead content of the entire igniting agent layer while maintaining the ignition ability.

The ignition ball according to the present invention is not limited to the gas generator used in the seat belt pretensioner described above, but may be an electric igniter such as a gas generator used in an airbag device of another automobile. It can be used for the field used. Also, in FIG. 1, the embolus is described as being formed of resin, but in addition to the igniter that seals the embolus with glass, the igniter that can employ an ignition ball employs the ignition ball of the present invention. Thus, the igniter of the present invention can be formed.
Furthermore, the ignition ball can further laminate an ignition charge layer on the second ignition charge layer as desired. Further, an intermediate layer may be provided between the first igniting agent layer and the second igniting agent layer. As the intermediate layer, for example, the same layer as the coating layer that coats the surface of the second pyrotechnic layer can be used.

[0036]

The present invention will be described more specifically with reference to the following examples. (Example 1) 50 parts by mass of lead trinitroresorcin, 50 parts by mass of potassium perchlorate, and 100 parts by mass of a solvent were mixed with 10 parts by mass of viton rubber dissolved therein. This mixture was applied to the surface of a railway bridge line at a thickness of 1.7 mm, dried and solidified to form a first ignition charge layer. Subsequently, 57 parts by mass of zirconium, 43 parts by mass of potassium perchlorate, and 10 parts of solvent 10
10 parts by mass of the dissolved viton rubber was mixed with 0 parts by mass. 0.8 mm thick on the surface of the first pyrotechnic layer
It was applied, dried and solidified to form a second pyrotechnic layer. An acetate vinyl resin (manufactured by Eastman Chemical Co., Ltd.) was applied to the surface of the second pyrotechnic layer to form a coating layer, which was used as an ignition ball. The amount of lead contained in the ignition charge layer is 2.1 as a metal.
mg.

Comparative Example 1 Lead Trinitroresorcinol 50
10 parts by mass of dissolved viton rubber was mixed with 50 parts by mass of potassium perchlorate and 100 parts by mass of a solvent. This mixture was applied to the surface of the electric bridge wire at a thickness of 2.5 mm, dried and solidified to form an ignition powder layer, and used as an ignition ball.
The amount of the lead compound contained in the ignition charge layer is 3.
2 mg.

(Comparative Example 2) 57 parts by mass of zirconium,
10 parts by mass of the dissolved viton rubber was mixed with 43 parts by mass of potassium perchlorate and 100 parts by mass of the solvent. This mixture was applied to the surface of the electric bridge wire at a thickness of 2.5 mm, dried and solidified to form an ignition charge layer, which was used as an ignition ball. The amount of the lead compound contained in the ignition charge layer is 0 mg.

The ignition balls according to Example 1 and Comparative Examples 1 and 2 were set in an electric igniter of a gas generator used for a seat belt pretensioner for an automobile, and the time required for ignition after energization was measured. Then, the ignition capacities were compared.

The one using the ignition ball according to the first embodiment is as follows.
Compared to Comparative Example 1 using a conventional ignition ball, there was no inferiority in terms of ignition ability. On the other hand, those using the ignition ball of Comparative Example 2 did not ignite.

[0041]

According to the present invention, by using a two-layered igniting agent layer, it is possible to obtain an ignition ball in which the content of a lead compound in the igniting agent layer is reduced while maintaining the ignition ability. Further, it is possible to provide an igniter used in an airbag device for a vehicle or a seatbelt pretensioner using an ignition ball having a reduced content of a lead compound.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of a main part of a gas generator using an igniter according to the present invention.

FIG. 2 is a view showing an embodiment of the structure of an ignition ball according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ignition ball 2 1st igniting agent layer 3 2nd igniting agent layer 4 Coating layer 5 Denbashi line 6 Steel part 7 Embolus 10 Tubular body 15 Transfer agent

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroshi Hori 3903-39, Tomicho, Himeji-shi, Hyogo Nippon Kayaku Co., Ltd. Himeji Plant (72) Inventor Kenjiro Ikeda 3903-39, Tomicho, Himeji-shi, Hyogo Japan Chemicals F-term in Himeji factory (reference) 3D018 MA02 MA05 3D054 DD22 DD28 FF20

Claims (6)

[Claims] 1. A cup-shaped tube, a transfer agent accommodated in the tube, an embolus, and an electric bridge line that generates heat when energized.
An igniter comprising an ignition ball formed on a surface of the bridge wire, wherein the ignition ball includes a first ignition charge layer containing a lead compound formed on a surface of the bridge wire, and An igniter characterized in that the igniter has a two-layer structure including a second pyrotechnic layer containing no lead compound formed on the surface of the first pyrotechnic layer. 2. The igniter according to claim 1, wherein a coating layer is formed on a surface of the second pyrotechnic layer. 3. The igniter according to claim 1, wherein the first igniting agent layer uses lead trinitroresorcinol as a fuel component, and the second igniting agent layer uses zirconium as a fuel component. 4. An electric bridge wire which generates heat when energized, a first igniter layer containing a lead compound formed on the surface of the electric bridge line, and a lead compound formed on the surface of the first igniter layer Characterized in that it has a two-layer structure with a second igniting agent layer containing no. 5. The ignition ball according to claim 4, wherein a coating layer is formed on a surface of the second pyrotechnic layer. 6. The ignition ball according to claim 4, wherein the first igniting agent layer uses lead trinitroresorcinol as a fuel component, and the second igniting agent layer uses zirconium as a fuel component.