JP2006199512A - Disk-form gas generator molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk-form gas generator molded article with good ignition combustibility when used by stacking a plurality of sheets of the article. <P>SOLUTION: The gas generator molded article 10 has, on at least one surface thereof, a plurality of wall-like projections 13a-13d, 14a-14d and 15a-15d formed so as to surround the circumference of the center hole 12 in a discontinuous manner, where any of the plurality of wall-like projections is positioned on a line connecting the center O of the gas generator molded article 10 and an arbitrary point (X<SB>1</SB>, X<SB>2</SB>, X<SB>3</SB>or the like) on the circumference. Consequently the flame, passing through gaps between the wall-like projections to get to the peripheral edge of the molded article 10, inevitably collides against the wall-like projection to be scattered in an arbitrary direction and is brought into contact with the surface of the molded article 10, thereby ignition combustibility is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disk-shaped gas generant molding and an air bag gas generator using the same.

  As a gas source of a gas generator for an air bag, a disk-shaped gas generant molding is widely used. This disk-shaped gas generant molded body is housed in a gas generator in a state of being stacked so as to form a cylinder as a whole (a cylindrical hollow portion is formed at the center), and when the gas generator is in operation. A flame runs in the hollow cylindrical portion, and the entire gas generant molded body stacked in a cylindrical shape is ignited and burned.

In such a combustion process, if a plurality of disk-shaped gas generant molded bodies are simply stacked, the molded bodies adjacent in the vertical direction are in close contact with each other, and therefore pass through the cylindrical hollow portion. Since it is difficult for the flame to pass in the circumferential direction of each molded body, the ignitability may be reduced. In order to solve such problems, Patent Literatures 1 to 5 disclose gas generant molded bodies in which various shapes of protrusions are provided on the surface of the molded body.
USP 5,507,890 USP 4,408,534 USP 6,077,372 USP 4,669,383 USP 5,101,730

  However, in the conventional gas generant molded body as described in Patent Documents 1 to 5, the projections continuously surround the center hole of the gas generant molded body, or the circle from the center of the gas generant molded body. Projections do not exist on the line connecting arbitrary points on the circumference. For this reason, the movement of the flame in the circumferential direction from the center hole of the gas generating agent molded body is hindered by the protrusion, or conversely, the flame moves at a stroke without hitting the protrusion from the center hole to the circumference.

  In an air bag system mounted on an automobile, it is necessary to inflate and deploy the air bag in about 30 to 60 msec. Therefore, it is important that the gas generating agent molded body serving as a gas source has good ignition and combustibility. It is important to improve the ignition combustibility when the gas generant molded bodies are stacked in a cylindrical shape.

  It is an object of the present invention to provide a disk-shaped gas generant molded body with improved ignition and combustion properties, particularly when stacked in a columnar shape, and an air gas generator using the same.

As a means for solving the problems, the present invention
It is a disk-shaped gas generant molding having a central hole in the center,
The gas generant molding has a plurality of wall-shaped protrusions formed so as to discontinuously surround the periphery of the center hole on at least one surface;
Provided is a disk-shaped gas generant molded body in which any of the plurality of wall-shaped protrusions is located on a line connecting the center of the disk-shaped gas generant molded body and an arbitrary point on the circumference.

  Since the wall-shaped protrusions discontinuously surround the periphery of the center hole, the circular wall-shaped protrusion 3 surrounding the center hole 2 is formed in the gas generating agent molded body 1 as shown in FIG. What is formed continuously is not included.

  When the gas generant molded bodies 1 as shown in FIG. 5 are stacked in a columnar shape, when the flame generated from the ignition means moves in the radial direction through the center hole 2 (the arrow in FIG. 5 indicates the traveling direction of the flame). ), The movement is hindered by the circular wall-shaped protrusion 3 and the molded body adjacent to the upper and lower sides, and the contact state between the flame and the molded body is deteriorated, so that the ignition and combustibility is lowered.

However, in the gas generant molded article of the present invention,
(A) The wall-like projections discontinuously surround the central hole,
(B) any of the plurality of wall-shaped protrusions is located on a line connecting the center of the disk-shaped gas generant molded body and any one point on the circumference;
It has the composition requirements.

  For this reason, the movement of the flame generated from the ignition means is not hindered by the action of the component (a) [hereinafter referred to as “action (a)”, and can always reach the periphery of the molded body, Further, due to the action of the constituent element (b) [hereinafter referred to as “action (b)”], the flame moving in the radial direction always hits the wall-shaped protrusion and is scattered in an arbitrary direction.

  Therefore, as a result of such actions (a) and (b), the contact time between the flame generated from the ignition means and the gas generating agent molded body becomes long, and the flame and the gas generating agent molded body come into contact with each other. As a result, the ignition and combustibility of the gas generant molding is improved.

  According to the present invention, as another means for solving the problem, the plurality of wall-shaped protrusions are of a shape along a circumference (a planar shape is a circle) or a linear shape. A disk-shaped gas generant molded article is provided.

  The present invention provides, as another means for solving the problems, a disk-shaped gas generant molded body according to claim 1 or 2, wherein the plurality of wall-shaped protrusions are formed on concentric circles having different diameters.

  For example, the center hole can be surrounded by double or triple wall-shaped protrusions so as to satisfy the structural requirements (a) and (b).

  In another aspect of the present invention, the disk-shaped gas generant molded body has a thickness of 1 to 12 mm, an outer diameter of 5 to 80 mm, an inner diameter of 2 to 20 mm, and a wall-like projection height of 0.1 mm. The disk-shaped gas generating agent molded body according to any one of claims 1 to 3, which is 1 to 2 mm.

  The length of the wall-shaped protrusion can be determined in relation to the number in the circumferential direction and the radial direction so as to satisfy the structural requirements (a) and (b).

The present invention provides a solution to other problems.
A gas generator for an air bag using the disk-shaped gas generant molded body according to any one of claims 1 to 4 as a gas generation source,
In the gas generator, a plurality of the disk-shaped gas generant molded bodies are stacked in a cylindrical shape so that the positions of the respective center holes are aligned, thereby forming a cylindrical hollow portion comprising the central holes of each molded body. Is housed as
When the ignition means of the gas generator is activated, the flame generated from the ignition means is transmitted from one end to the other end of the cylindrical hollow portion, and further transmitted in the circumferential direction from the center hole of each gas generating agent molded body A gas generator for an air bag in which the ignition combustibility of the gas generating agent molded body is enhanced by the flame colliding with a wall-like protrusion and scattering in a random direction is provided.

  Since the gas generating agent molded body of the present invention has improved ignition and combustibility, by using this as a gas source, the operating state of the gas generator for the air bag is also improved.

  The gas generating agent molded body of the present invention has improved ignition and combustibility when stacked and used in a cylindrical shape.

(1) Gas generant molded body of FIGS. 1 and 2 FIG. 1 is a plan view of the gas generant molded body of the present invention, and FIG. 2 (however, the gas generant molded body 10 in FIG. 2) It is sectional drawing between the II-II lines of FIG. The dimensions in the drawings do not mean actual dimensions. 2 is added to explain a state in which a plurality of gas generant molded bodies are stacked, and is not included in the cross-sectional view of FIG.

  The gas generant molded body 10 has an annular main body 11 and a center hole 12. A wall-shaped protrusion is provided on one surface (the illustrated surface) of the annular main body 11 so as to discontinuously surround the center hole 12.

  Wall-shaped protrusions 13a, 13b, 13c, and 13d are formed at positions closest to the center hole 12, and these are positioned concentrically. As illustrated, there is a gap between the wall-shaped protrusions 13a to 13d.

  Wall-shaped protrusions 14a, 14b, 14c, and 14d are formed around the wall-shaped protrusions 13a to 13d, and these are positioned concentrically. As illustrated, a gap exists between the wall-shaped protrusions 14a to 14d.

  Wall-shaped protrusions 15a, 15b, 15c, and 15d are formed around the wall-shaped protrusions 14a to 14d, and these are positioned concentrically. As illustrated, a gap exists between the wall-shaped protrusions 15a to 15d.

  The radial spacing between the wall-shaped protrusions 13a to 13d, the wall-shaped protrusions 14a to 14d, and the wall-shaped protrusions 15a to 15d is not particularly limited as long as the structural requirements (a) and (b) are satisfied. The intervals may be equal or different.

  The wall-shaped protrusions are formed in a triple manner surrounding the center hole 12 (one having the same distance from the point O in the radial direction is combined), and the wall-shaped protrusions 13a to 13d, Since there are gaps between the protrusions 14a to 14d and the wall protrusions 15a to 15d, the periphery of the center hole 12 is discontinuously surrounded by the wall protrusions. Note that the wall-shaped protrusions are not formed on the back surface (not shown).

By arranging the wall-like projections in this way, when the center of the gas generating agent molded body 1 is the point O, the point O and any one point on the circumference of the gas generating agent molded body 10 (for example, Any wall-like protrusion is always present on the line connecting X ₁ , X ₂ , and X ₃ ).

  The dimensions of the gas generant molded body 10 can be as follows, but are not limited thereto, and can be appropriately modified according to the gas generator to be used.

The thickness is preferably 1 to 12 mm, more preferably 1.5 to 5 mm.
The outer diameter is preferably 5 to 80 mm, more preferably 10 to 65 mm.
The inner diameter (diameter of the center hole 12) is preferably 2 to 20 mm, more preferably 5 to 15 mm,
The height of the wall projection is preferably 0.1 to 2 mm, more preferably 0.2 to 0.8 mm,
The length of the wall-shaped protrusion is preferably 2 to 40 mm, more preferably 3 to 30 mm.

  The gas generant moldings 10 shown in FIGS. 1 and 2 are stacked in a cylindrical shape (for example, the required number is sequentially stacked like the gas generant moldings 10 and 10 ′ in FIG. 2). 1 and the ignition means ignites, the actions (a) and (b) are performed, so that the flame moves, for example, from the center hole 12 in the direction of the arrow in FIG. For this reason, the contact time between the flame generated from the ignition means and the gas generating agent molded body (the front surface of the gas generating agent molded body 10 with the wall-like protrusions and the back surface of the gas generating agent molded body 10 'without the wall-like protrusions). Becomes longer, and the entire surface of the flame and gas generant molding (when stacked in a cylindrical shape, the front and back surfaces of each gas generant molding excluding the lowermost layer and the uppermost gas generant molding) Therefore, the ignition combustion property is improved.

  The gas generant molded body is obtained by molding a gas generant composition into a predetermined shape. For example, after adding or mixing water or an organic solvent to the gas generant composition, compression molding is performed using a tableting machine or the like. It can be manufactured by a method.

  As the gas generating composition, known ones can be used, for example, described in JP-A No. 2001-320991, JP-A No. 2002-12493, JP-A No. 2002-29880, and JP-A No. 2004-155645. Among them, those described in the following 2004-155645 are preferable.

  (A) an organic compound as a fuel, (b) an oxygen-containing oxidant and (c) aluminum hydroxide, and if necessary, further from (d) a binder and / or (e) a metal oxide or metal carbonate A gas generant composition containing selected additives.

  Examples of the organic compound as the component (a) fuel include at least one selected from tetrazole compounds, guanidine compounds, triazine compounds, and nitroamine compounds.

  The tetrazole compound is preferably 5-aminotetrazole, bitetrazole ammonium salt or the like. The guanidine compound is preferably guanidine nitrate (guanidine nitrate), aminoguanidine nitrate, nitroguanidine, triaminoguanidine nitrate or the like. The triazine compound is preferably melamine, cyanuric acid, ammelin, ammelide, ammeland and the like. The nitroamine compound is preferably cyclo-1,3,5-trimethylene-2,4,6-trinitramine.

  The oxygen-containing oxidant of component (b) may contain (b-1) basic metal nitrate, nitrate, ammonium nitrate, and (b-2) at least one selected from perchlorate and chlorate. preferable.

  As the basic metal nitrate of component (b-1), basic copper nitrate, basic cobalt nitrate, basic zinc nitrate, basic manganese nitrate, basic iron nitrate, basic molybdenum nitrate, basic bismuth nitrate and base And at least one selected from basic cerium nitrate.

The basic metal nitrate has an average particle size of preferably 30 μm or less and more preferably 10 μm or less in order to increase the burning rate. The average particle size is measured by a particle size distribution method using laser scattered light. The measurement sample was obtained by dispersing a basic metal nitrate in water and then irradiating with ultrasonic waves for 3 minutes, obtaining a 50% cumulative value (D ₅₀ ) of the number of particles, and calculating the average value of two measurements. Average particle diameter.

  Examples of the nitrate of component (b-1) include alkaline metal nitrates such as potassium nitrate and sodium nitrate, and alkaline earth metal nitrates such as strontium nitrate.

  The (b-2) component perchlorate and chlorate are components that also have a combustion promoting action as well as an oxidizing action. Oxidation means the action of efficiently producing combustion by generating oxygen during combustion and reducing the amount of toxic gases such as ammonia and carbon monoxide. On the other hand, the combustion promoting action means an action for improving the ignitability of the gas generant composition or an action for improving the combustion rate.

  Examples of the perchlorate and chlorate include at least one selected from ammonium perchlorate, potassium perchlorate, sodium perchlorate, potassium chlorate, and sodium chlorate.

  (C) The component aluminum hydroxide is used as a water and water flocculation aggregate, for household water phosphorus-free detergents, and as an additive for resin and rubber. It is low and has a high decomposition start temperature.

  Further, when pyrolyzing, it absorbs a large amount of heat, generating aluminum oxide and water. For this reason, the inclusion of aluminum hydroxide lowers the combustion temperature of the gas generant composition and acts to reduce the amount of toxic nitrogen oxides and carbon monoxide produced after combustion. Such a toxic gas reducing action is particularly noticeable when the component (b-2) is used as an oxidizing agent.

  Aluminum hydroxide can improve the overall dispersibility when mixing the components (a) to (c) by adjusting the average particle diameter, so that the mixing work is facilitated and the gas obtained The ignitability of the generator composition is also improved.

  The average particle diameter of aluminum hydroxide is preferably 0.1 to 70 μm, more preferably 0.5 to 50 μm, and still more preferably 2 to 30 μm. The method for measuring the average particle size is the same as the method for measuring the average particle size of the basic metal nitrate.

  The binder of component (d) is a component used together with components (a) to (c) or (a) to (c) and (e) as necessary, and molding a gas generant composition. It is a component that improves the properties and increases the strength of the gas generant molded body. If the molding strength of the gas generant molded body is not strong, the molded body may collapse when it is actually burned, causing runaway combustion, and control of combustion may not be possible.

  Examples of the binder include carboxymethyl cellulose, carboxymethyl cellulose sodium salt, carboxymethyl cellulose potassium salt, carboxymethyl cellulose ammonium salt, cellulose acetate, cellulose acetate butyrate, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl ethyl cellulose, fine Crystalline cellulose, polyacrylamide, aminated product of polyacrylamide, polyacryl hydrazide, acrylamide / metal acrylate copolymer, copolymer of polyacrylamide / polyacrylate compound, polyvinyl alcohol, acrylic rubber, guar gum, starch, At least one selected from silicone And the like.

  (E) Component selected from metal oxide and metal carbonate of component is component used together with components (a) to (c) or (a) to (c) and (d) as necessary For the purpose of assisting the action of aluminum hydroxide, that is, reducing the combustion temperature of the gas generating agent, adjusting the combustion speed, and reducing the amount of toxic nitrogen oxides and carbon monoxide produced after combustion. It is what you add.

  Additives include metal oxides such as copper oxide, iron oxide, zinc oxide, cobalt oxide, manganese oxide, molybdenum oxide, nickel oxide, bismuth oxide, silica, and alumina; cobalt carbonate, calcium carbonate, basic zinc carbonate, base Metal carbonates such as basic copper carbonate or basic metal carbonates; complex compounds of metal oxides or hydroxides such as acid clay, kaolin, talc, bentonite, diatomaceous earth, hydrotalcite; sodium silicate, mycamolybdic acid Examples thereof include at least one selected from salts, metal acid salts such as cobalt molybdate and ammonium molybdate, molybdenum disulfide, calcium stearate, silicon nitride, and silicon carbide.

  The content ratio of each component contained in the gas generant composition used in the present invention and the formulation examples are as follows.

(1) Composition of components (a) to (c) The content of the organic compound (a) is preferably 10 to 60% by mass, more preferably 5 to 60% by mass, and still more preferably 10 to 55% by mass. %;
(B-1) Content of the oxidizing agent of a component becomes like this. Preferably it is 10-85 mass%, More preferably, it is 20-70 mass%, More preferably, it is 30-60 mass%;
(B-2) Content of the oxidizing agent of a component becomes like this. Preferably it is 0.5-20 mass%, More preferably, it is 1-10 mass%, More preferably, it is 1-5 mass%;
(C) Content of the aluminum hydroxide of a component is 0.1-20 mass%, Preferably it is 3-15 mass%, More preferably, it is 4-10 mass%.

(Formulation example 1)
(A) Guanidine nitrate 30-60% by mass
(B) Basic copper nitrate 30-60 mass%
(C) Aluminum hydroxide 3 to 10% by mass
(Formulation example 2)
(A) Nitroguanidine 25-60% by mass
(B) Basic copper nitrate 30-60 mass%
(C) Aluminum hydroxide 3-15 mass%.

(Formulation example 3)
(A) Guanidine nitrate or melamine (b-1) Basic copper nitrate (b-2) At least one perchlorate selected from sodium perchlorate, potassium perchlorate and ammonium perchlorate (c) Water Aluminum oxide.

(Formulation example 4)
(A) Guanidine nitrate or melamine (b-1) Basic copper nitrate (b-2) Sodium chlorate or potassium chlorate (c) Aluminum hydroxide.

(3) The composition containing any one or both of the component (d) and the component (e) with respect to the components (a) to (c). The content of the component (d) is preferably 20% by mass or less, More preferably, it is 0.5-10 mass%, More preferably, it is 1-7 mass%;
(E) Content of a component becomes like this. Preferably it is 20 mass% or less, More preferably, it is 1-15 mass%, More preferably, it is 3-10 mass%.

(Formulation example 5)
(A) Nitroguanidine (b) Strontium nitrate (c) Aluminum hydroxide (d) Carboxymethylcellulose sodium salt or guar gum.

(Formulation example 6)
(A) Nitroguanidine (b) Basic copper nitrate (c) Aluminum hydroxide (d) Guam gum.

(Formulation example 7)
(A) Melamine (b) Basic copper nitrate (c) Aluminum hydroxide (d) Carboxymethylcellulose sodium salt or guar gum.

(Formulation example 8)
(A) Guanidine nitrate (b) Basic copper nitrate (c) Aluminum hydroxide (d) Carboxymethylcellulose sodium salt or guar gum.

(Formulation example 9)
(A) Two-component or three-component mixed fuel selected from guanidine nitrate, nitroguanidine and melamine (b) Basic copper nitrate (c) Aluminum hydroxide (d) Carboxymethylcellulose sodium salt or guar gum.

(Formulation example 10)
(A) Guanidine nitrate or melamine (b-1) Basic copper nitrate (b-2) At least one perchlorate selected from sodium perchlorate, potassium perchlorate and ammonium perchlorate (c) Water Aluminum oxide (d) Carboxymethylcellulose sodium salt or guar gum.

(Formulation example 11)
(A) Guanidine nitrate or melamine (b-1) Basic copper nitrate (b-2) Sodium chlorate or potassium perchlorate (c) Aluminum hydroxide (d) Carboxymethylcellulose sodium salt or guar gum.

(2) Gas Generating Agent Molded Body in FIG. 3 FIG. 3 is a plan view of another form of the gas generant molded body 20, which is different from that in FIG. 1 in that the planar shape of the wall-shaped protrusion is linear. ing. In the figure, the same reference numerals as those in FIG. In addition, what shape | molded the above-mentioned well-known gas generating agent composition can be used for a gas generating agent molded object.

  Wall-shaped protrusions 23a, 23b, 23c, and 23d are formed at positions closest to the center hole 12, and there are gaps between the wall-shaped protrusions 23a to 23d as shown in the figure.

  Wall-shaped protrusions 24a, 24b, 24c, and 24d are formed around the wall-shaped protrusions 23a to 23d, and there are gaps between the wall-shaped protrusions 24a to 24d as illustrated.

  The distance in the radial direction between the wall-shaped protrusions 23a to 23d and the wall-shaped protrusions 24a to 24d is not particularly limited as long as the structural requirements (a) and (b) are satisfied, and may be equal or different. .

  The wall-shaped protrusions are formed in a double manner so as to surround the center hole 12. Since the wall-shaped protrusions 23 a to 23 d and the wall-shaped protrusions 24 a to 24 d all have a gap, the center hole 12. Is surrounded by a wall-like protrusion discontinuously. Note that the wall-shaped protrusions are not formed on the back surface (not shown).

  When the gas generating agent molded body 20 shown in FIG. 3 is stacked in a cylindrical shape and accommodated in a gas generator and ignited by the ignition means, the actions (a) and (b) are performed, and FIG. Ignition and combustibility is improved in the same manner as the above.

(3) Gas Generating Agent Molded Body in FIG. 4 FIG. 4 is a plan view of another form of the gas generant molded body 30, which is the same as that in FIG. 1 except that the arrangement state of the wall projections is different. In the figure, the same reference numerals as those in FIG. In addition, what shape | molded the above-mentioned well-known gas generating agent composition can be used for a gas generating agent molded object.

  Wall-like projections 33a and 33b are formed at positions closest to the center hole 12, and these are located on concentric circles. As illustrated, there is a gap between the wall-shaped protrusions 33a and 33b.

  Wall-like protrusions 34a and 34b are formed around the wall-like protrusions 33a and 33b, and these are located concentrically. As shown in the figure, there is a gap between the wall-shaped protrusions 34a and 34b.

  Wall-shaped protrusions 35a, 35b, 35c, and 35d are formed around the wall-shaped protrusions 34a and 34b, and these are positioned concentrically. As illustrated, there is a gap between the wall-shaped protrusions 35a to 35d.

  The distance in the radial direction between the wall-shaped protrusions 33a and 33b, the wall-shaped protrusions 34a and 34b, and the wall-shaped protrusions 35a to 35d is not particularly limited as long as the structural requirements (a) and (b) are satisfied. The intervals may be equal or different.

  The wall-shaped projections are formed in a triple manner surrounding the center hole 12, and there are gaps in the wall-shaped projections 33a and 33b, the wall-shaped projections 34a and 34b, and the wall-shaped projections 35a to 35d. Therefore, the circumference of the center hole 12 is discontinuously surrounded by the wall-shaped protrusions. Note that the wall-shaped protrusions are not formed on the back surface (not shown).

  When the gas generating agent molded body 30 shown in FIG. 4 is stacked in a cylindrical shape and accommodated in a gas generator and ignited by the ignition means, the actions (a) and (b) are performed, so that FIG. Ignition and combustibility is improved in the same manner as the above.

(4) Gas generator for airbag The gas generating agent molded body shown in FIGS. 1 to 4 is, for example, a known gas generator illustrated in USP 5,507,890, USP 4,669,383, USP 5,062,367. It can be used for the gas generator shown in FIG. FIG. 6 is a longitudinal sectional view of a gas generator for an air bag.

  The gas generator 100 shown in FIG. 6 uses a cylindrical housing 101 that is particularly long in the axial direction, and two combustion chambers 103a and 103b partitioned by a partition wall 102 are adjacent to each other in the axial direction. Is formed. In the present embodiment, the first combustion chamber 103a is formed with a larger volume than the second combustion chamber 103b.

  A plurality of gas discharge ports 105 are formed in a range where the combustion chambers 103a and 103b exist inside the wall surface (that is, the peripheral wall surface) along the length direction of the housing 101. Coolants 106a and 106b are arranged opposite to the inner wall surface.

  Ignition devices 107a and 107b are installed at both ends of the housing 101 that is long in the axial direction. In this embodiment, the ignition devices 107a and 107b are activated by receiving an electronic activation signal and generating an electric igniter 171 that generates a flame, a thermal mist, and the like. It is configured to include a charge 172 that amplifies the momentum such as flame and heat mist.

  Since the ignition devices 107a and 107b are installed at the axial end of the housing 101 formed in a cylindrical shape, when the gas generator 100 is manufactured, the coolants 106a and 106b and the gas generating agent are molded in the housing 101. After the necessary members such as the bodies 104a and 104b are installed, the ignition devices 107a and 107b including the igniter 171 can be installed in the final manufacturing stage.

  When the igniter 171 is installed from the early stage of manufacturing the gas generator 100, if the igniter 171 malfunctions due to static electricity or the like, the gas generating agents 104a and 104b are ignited and burned, resulting in damage to the manufacturing equipment. However, as shown in this embodiment, the ignition device 107a, 107b is installed at the end of the housing 101, and can be incorporated at the final manufacturing stage, so that the gas generator 100 is being manufactured. Can be avoided as much as possible.

  The ignition devices 107a and 107b are accommodated in an ignition device accommodation chamber that is partitioned by a retainer 108 at an axial end portion in the housing 101. The retainer 108 that divides the ignition device housing chamber and the combustion chambers 103a and 103b concentrates ignition energy composed of combustion products such as flame, heat mist, and high-temperature gas generated by the operation of the ignition devices 107a and 107b. A nozzle 181 is provided for releasing the gas, and one end of the heat transfer tube 109 is sandwiched in the nozzle 181.

  In the present embodiment, the heat transfer tubes 109a and 109b are formed using a metal spiral tube, and in particular, the pitch P is smaller on the ignition device housing chamber side (one end side) and on the other end side. Is formed greatly. The heat transfer tubes 109a and 109b are disposed at the center (axial center) positions in the combustion chambers 103a and 103b, and exist over the entire length in the combustion chambers 103a and 103b. The other end sides of the heat transfer tubes 109 a and 109 b are supported by a protrusion 121 provided on the partition wall 102.

  In FIG. 6, by changing the pitch P by changing the width of the air gap S and the spiral wall width W, the aperture ratio of the air gap S is decreased on the igniter side and increased as the distance from the igniter increases. In addition, the pitch P can be changed by changing the width S of the gap S by changing the width of the gap S, or the pitch P can be changed by changing the wall width W by changing the width of the gap S. Thus, the opening ratio of the air gap S is small on the igniter side and can be increased as the distance from the igniter increases. Of course, a spiral tube having a constant pitch P may be used.

  The fire transfer tube 109a in the combustion chamber 103a accommodates a disk-shaped gas generating agent molded body (as shown in FIGS. 1 to 4) 104a. The gas generating agent molded body 104a is laminated so as to be entirely cylindrical by passing the central hole 12 through the heat transfer tube 109a (stacked as shown in FIG. 2). Only the generator molding is displayed, the others are omitted).

  A fire transfer tube 109b in the combustion chamber 103b accommodates a disk-shaped gas generating agent molded body (as shown in FIGS. 1 to 4) 104b. The gas generating agent molded body 104b is laminated so as to be entirely cylindrical by passing the center hole 12 through the heat transfer tube 109b (in FIG. 6, two gas sheets are laminated). Only the generator molding is displayed, the others are omitted).

  The coolants 106a and 106b provided to face the inner peripheral surface of the housing 101 are at least one of a function of cooling the gas generated in the combustion chambers 103a and 103b and a function of collecting residues in the combustion gas. It is formed in an annular shape, and is arranged with a gap between the outer peripheral surface and the housing 101 peripheral wall surface. Due to this gap, the combustion gas generated in the interior passes through the entire region of the coolant 106a, 106b and reaches the gas discharge port 105, so that the filtration efficiency and the cooling efficiency of the coolant are improved.

  In the gas generator 100 formed in this manner, when the ignition device 107a, 107b is activated upon receipt of the operation signal, the ignition energy consisting of combustion products such as flame, heat mist, and high-temperature gas is It is discharged from the nozzle 181 of the retainer 108 in a concentrated manner.

  In this nozzle 181, fire transfer tubes 109a and 109b made of a spiral tube are fitted, and since both communicate with each other, the ignition energy moves in the spiral tube.

  And since the helical space | gap S is provided in the surrounding wall surface of this spiral tube, the said ignition energy will be ejected from the space | gap S in a substantially radial direction. At this time, in the gas generating agent molded bodies (as shown in FIGS. 1 to 4) 104a and 104b laminated in a columnar shape, since the actions (a) and (b) are performed, the combustibility is very high. good.

  In particular, the heat transfer tubes 109a and 109b and the pitch P in the present embodiment are formed on the peripheral wall surfaces of the heat transfer tubes 109a and 109b because the ignition devices 107a and 107b are formed smaller and gradually larger. The width (or area) of the gap S formed is small on the ignition device 107a, 107b side (one end side) and large on the opposite side (other end side). As a result, ignition energy generated by the operation of the ignition devices 107a and 107b is not released in a large amount in the vicinity of the nozzle 181 of the retainer 108, but the entire length direction of the combustion chambers 103a and 103b (gas generation stacked in a columnar shape). It is discharged evenly over the entire length direction of the agent molded bodies 104a and 104b.

  Thereby, the gas generating agent molded bodies 104a and 104b are uniformly ignited, and the gas for inflating the airbag can be optimally released for the operation of the gas generator. Furthermore, the spiral tube used as the heat transfer tubes 109a and 109b is made of a material (preferably a belt-shaped material formed in a square or round cross section) drawn around by drawing or rolling around the mandrel. Since it can be manufactured by winding, it is easy to manufacture, and it is possible to easily manufacture the gas generator 100 for an air bag and to further reduce the manufacturing cost.

  In particular, in the gas generator 100 shown in FIG. 6, two combustion chambers 103a and 103b having different volumes are provided in the housing 101, and ignition devices 107a and 107b are provided corresponding to the respective combustion chambers 103a and 103b. Therefore, in operation, the gas generating agents 104a and 104b can be ignited independently of each other. Thereby, operation | movement performance (the generation | occurrence | production condition of the gas for inflation of an airbag) can be adjusted arbitrarily.

  In particular, the difference in volume between the combustion chambers 103a and 103b is the difference in the amount of the gas generating agents 104a and 104b accommodated therein, so that the gas in any of the combustion chambers 103a and 103b is burned first. The operation performance of the gas generator 100 can be adjusted more finely depending on, for example, which combustion chamber 103a, 103b only the gas in the combustion chamber is combusted.

The top view of a gas generating agent molding. Sectional drawing of the II-II line | wire of FIG. The top view of the gas generating agent molding of another form. The top view of the gas generating agent molding of another form. The top view of the gas generating agent molding of a prior art. The longitudinal direction end view of the gas generator for airbags.

Explanation of symbols

10, 20, 30 Gas generant molding
11 Annular body
12 Center hole
13a-13d wall projection
14a-14d wall projection
15a-15d wall projection

Claims (5)

It is a disk-shaped gas generant molding having a central hole in the center,
The gas generant molding has a plurality of wall-shaped protrusions formed so as to discontinuously surround the periphery of the center hole on at least one surface;
A disk-shaped gas generating agent molded body, wherein any one of the plurality of wall-shaped protrusions is located on a line connecting the center of the disk-shaped gas generating agent molded body and an arbitrary point on the circumference.   The disk-shaped gas generant molding according to claim 1, wherein the plurality of wall-shaped protrusions have a shape along a circumference or a linear shape.   The disk-shaped gas generating agent molded body according to claim 1 or 2, wherein the plurality of wall-shaped protrusions are formed on concentric circles having different diameters.   The thickness of the disk-shaped gas generant molding is 1 to 12 mm, the outer diameter is 5 to 80 mm, the inner diameter is 2 to 20 mm, and the height of the wall-shaped protrusion is 0.1 to 2 mm. The disk-shaped gas generating agent molded body according to any one of the above. A gas generator for an air bag using the disk-shaped gas generant molded body according to any one of claims 1 to 4 as a gas generation source,
In the gas generator, a plurality of the disk-shaped gas generant molded bodies are stacked in a cylindrical shape so that the positions of the respective center holes are aligned, thereby forming a cylindrical hollow portion comprising the central holes of each molded body. Is housed as
When the ignition means of the gas generator is activated, the flame generated from the ignition means is transmitted from one end to the other end of the cylindrical hollow portion, and further transmitted in the circumferential direction from the center hole of each gas generating agent molded body A gas generator for an air bag in which the ignition combustibility of the gas generating agent molded body is enhanced by the flame colliding with a wall-shaped protrusion and scattering in a random direction.

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