JP2005313752A - Gas producer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas producer capable of restricting the number of component parts, reducing the number of steps in manufacturing and assembling operation and realizing a low cost air-bag module. <P>SOLUTION: This gas producer 1 comprises a cylindrical housing 4, gas producing agent 5 filling the housing 4 to generate a high-temperature gas through its combustion, filter material 7 loaded in the housing 4, and ignition unit 10 installed at one end 3 of the housing 4 to ignite and burn the gas producing agent 5 in the housing 4. Bolts 30a, 30b having a head to be fixed to a vehicle are directly arranged at the housing 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a small cylindrical gas generator used for a safety device of an automobile.

A side airbag is known as one of safety devices for protecting an occupant from an impact caused by a car collision. This side airbag operates with a large amount of high-temperature and high-pressure gas generated by a gas generator. Conventionally, the gas generator used for the side airbag generates gas as a method of generating gas, and a small amount of explosive composition for supplying heat to the high-pressure gas in each cylinder. There is known a hybrid system in which a large amount of high-temperature and high-pressure gas is released by an object (for example, see Patent Document 1).
JP-A-8-253100

  Patent Document 2 discloses an invention that uses a headed bolt and a cylindrical case as a member for attaching an airbag module using such a hybrid gas generator to a vehicle. Specifically, a head bolt is attached from the inside to the hole of the cylindrical case in which the cylindrical gas generator is housed, and the screw portion of the head bolt protrudes out of the case. The gas generator is attached to the vehicle by engaging and fixing the head bolt to the vehicle while sandwiching the head of the head bolt with the case.

JP-A-10-001018

  In order to attach the gas generator to the vehicle, it is necessary to separately use an attachment member such as a cylindrical case as described above, and there is a problem in that the airbag module is increased in size, weight, and cost.

  An object of the present invention is to provide a gas generator capable of reducing the number of parts, reducing the number of manufacturing and assembly steps, and realizing a low-cost airbag module.

Means and effects for solving the problems

  The gas generator of the present invention includes a cylindrical housing, a gas generating agent that fills the housing and generates a high-temperature gas by combustion, a filter material that is mounted in the housing, and one end of the housing And an igniter for igniting and burning the gas generating agent in the housing, wherein a head bolt for attaching to a vehicle is provided directly on the housing, It can be suitably used for an air bag.

  According to the present invention, since the gas generator can be attached to the vehicle without using a separate attachment member, there is an advantage that the airbag module can be reduced in size, weight, and cost. Such a configuration could not be adopted for safety in a conventional hybrid gas generator. In addition, since the mounting member is a headed bolt, the mounting and fixing work to the vehicle can be done only by a single work of tightening the nut to the screw portion protruding from the airbag module, and the working efficiency is extremely good.

  In the present invention, it is preferable that the headed bolt is welded to the housing by welding. According to this, compared with making it adhere | attach with an adhesive agent etc., the joint strength of a gas generator and a head bolt can be raised.

  In this invention, it is preferable to form the curved part which has a curvature comparable as the outer peripheral surface of the said housing in the head of the said headed bolt. According to this, the adhesion between the headed bolt and the cylindrical housing can be enhanced, the joining can be facilitated, and the joining strength can be enhanced.

  Hereinafter, embodiments of a gas generator according to the present invention will be described with reference to the drawings.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a gas generator. The gas generator 1 includes a cylindrical housing 4, a partition member 9 that divides the housing 4 into a combustion chamber 6 and a filter chamber 8, an igniter 10 that ignites and burns the gas generating agent 5 in the combustion chamber 6, Head bolts 30a and 30b are welded to the outer periphery of the housing 4 by welding or the like. A filter material 7 is attached to the filter chamber 8.

  The housing 4 has a bottomed cylindrical shape with one end 3 opened and the other end 2 closed. The one end 3 is preferably cylindrical. The other end 2 of the housing 4 may be any shape such as a rounded shape or a square shape, but a flat bottom shape (see FIG. 1) or a convex curved shape as shown in the drawing is preferable. For this reason, even if it is a case where the pressure in the housing 4 rises, it does not deform | transform. Further, since the other end 2 is closed in this way, only the one end 3 needs to be sealed, the number of parts can be reduced, and the sealing portion is only one place at the one end 3. Therefore, it is possible to improve the safety of the gas generator 1 and reduce the size. Further, the housing 4 has a straight cylindrical shape as shown in FIG. 2, but when the partition member 9 is fixed by caulking by a method to be described later, the cylindrical shape having irregularities as shown in FIG. It becomes. The housing 4 is made of a metal such as stainless steel, aluminum, or iron.

  A gas discharge hole 11 is provided on the outer periphery of the other end 2 of the housing 4. The gas discharge hole 11 is preferably provided at a position where no propulsive force is generated in the gas generator at the time of gas discharge, for example, in the cylindrical portion 20 of the filter chamber 8, and a plurality of gas discharge holes 11 may be provided. It is preferable that four are provided for each. From these gas discharge holes 11, the high-temperature and high-pressure gas generated by the combustion of the gas generating agent 5 in the combustion chamber 6 passes through the filter material 7 mounted in the filter chamber 8, and is cooled and filtered. Is done.

  The partition member 9 is a flat annular plate and has a hole 18. The partition member 9 is inserted into a predetermined position in the housing 4 from the one end portion 3, and is then caulked from the outer peripheral portion of the housing 4, so that the partition member 9 is fixed in the housing 4. It is divided into a generating agent chamber (combustion chamber) 6. In the gas generator 1 of the present embodiment that is preferably used for inflating the side airbag or the like, a relatively large amount of chemicals such as the gas generating agent 5 is used. It is preferable to prevent the filter material 7 from being damaged by the combustion heat of the gas generating agent 5 by partitioning the combustion chamber 6. The partition member 9 is made of, for example, stainless steel or iron.

  In the combustion chamber 6, a cylindrical gas generating agent 5 and an enhancer agent 14 are filled in two layers of a gas generating agent 5 layer and an enhancer agent 14 layer in direct contact with each other. The enhancer agent 14 is protected by the cushion material 15 from being powdered by vibration.

  A seal member 16 such as an aluminum tape is attached to one or both of the inner peripheral side of the housing 4 where the gas discharge hole 11 is located and the partition member 9. Thereby, the inside of the housing 4 is sealed. It is preferable that the seal member 16 is attached to the upper surface of the partition member 9 and not attached to the gas discharge hole 11 side. The seal member 16 may be larger than the diameter of the hole 18 by 4 mm or more. The attachment to the partition member 9 is simple, and this attachment can reduce the manufacturing cost of the gas generator 1.

  A holder 12 that holds the igniter 10 is attached to one end 3 of the housing 4 to close the one end 3 of the housing 4. As the igniter 10, it is preferable that the embolus is made of plastic or resin. This is because the cost can be reduced. Of course, it is also possible to use a conventional embolus formed of glass. In addition, the holder 12 is inserted into the one end portion 3 of the housing 4 and caulked together with the shaft end portion 13 of the housing 4, thereby being held by the housing 4 and closing the one end portion 3 of the housing 4.

  In the housing 4, head bolts 30 a and 30 b as mounting members for mounting on the vehicle are arranged side by side in the same axial direction on the peripheral surface of the housing 4 so as not to cover the gas discharge holes 11 drilled in the housing 4. It is welded by welding. The external appearance of the housing 4 of the gas generator of 1st Embodiment is shown in FIG. A distance w1 between the head bolts 30a and 30b is equal to a distance w1 between airbag mounting holes provided in a vehicle (not shown). The length h1 of the head bolts 30a and 30b is an appropriate length for attaching to the vehicle with a nut via the airbag module. As shown in FIG. 3, a curved portion 101 having a curvature R1 of the same degree as the outer peripheral surface of the housing 4 is formed on the heads of the head bolts 30a and 30b. it can. The number of head bolts may not be two. The head bolts 30a and 30b are preferably made of a metal that can be easily welded to the housing, such as iron or stainless steel.

  In FIG. 1, for example, a columnar or cylindrical shape, preferably a cylindrical shape is used as the filter material 7 by an aggregate of knitted wire mesh, plain weave wire mesh, or crimp-woven metal wire. In the gas generator in which the other end portion 2 of the housing 4 has a flat bottom shape, the filter material 7 preferably has a cylindrical shape or a columnar shape, and FIG. 1 exemplifies that having a cylindrical shape. Yes. The filter material 7 is mounted in contact with the tip of the other end 2 of the housing 4. Then, it is pressed and fixed to the other end 2 of the housing 4 by a partition member 9 formed of metal or the like that partitions the inside of the housing 4.

  The cushion material 15 is formed with a cross-shaped notch for reliably transmitting the power of the flame from the igniter 10 to the enhancer agent 14 without delay. The cushion material 15 is preferably formed by using an elastic material such as silicon rubber or silicon foam formed of ceramic fiber, foamed silicon, or the like.

Here, the igniter 10 will be described with reference to FIGS.
As shown in FIG. 4, the igniter 10 includes an embolus 84 having a pair of mutually insulated electrode pins 82 and 83, and a thin film bridge 85 attached to the embolus 84. A current is supplied to the thin film bridge 85 through the electrode pins 82 and 83, and the thin film bridge 85 is operated to ignite the explosives 86 and 87 loaded in the first tubular body 89.

  The embolus 84 is made of a metal such as stainless steel, aluminum, copper, or iron. In addition, the pair of electrode pins 82 and 83 extending from the plug 84 is formed of a metal such as stainless steel, aluminum, copper, or iron, as with the plug 84. The electrode pins 82 and 83 are covered with an insulator 91 such as glass or resin in the embolus 84 and insulated from each other. Further, the end surfaces of these electrode pins 82 and 83 are provided so as to be substantially flush with the head portion 95 of the embolus 84.

  FIG. 5 is an enlarged plan view of a portion where the thin film bridge 85 is embedded in the recess 92 of the embolus 84. FIG. 6 is a cross-sectional view taken along line A-A ′ in FIG. 5.

  As shown in FIGS. 5 and 6, the thin film bridge 85 is embedded in a recess 92 formed in the embolus 84 and is installed so as to be substantially flush with the embolus 84 and the electrode pins 82 and 83. Since the groove depth h10 of the recess 92 is usually more than 0.2 mm and 1 mm or less, preferably more than 0.2 mm and 0.75 mm or less, more preferably more than 0.2 mm and 0.5 mm or less, the thin film bridge When 85 is embedded, the step height h20 with respect to the heads of the electrode pins 82 and 83 is set to 1 mm or less, preferably 0.5 mm or less, and more preferably 0.2 mm or less, thereby making the wire bonding loop height h30. Can be lowered. Further, as shown in FIG. 6, so-called lateral attachment can be easily performed by using the peripheral surface of the wire 88 in a state where the wire 88 is laid down. Thus, since the loop height h30 of the wire 88 is usually 1 mm or less, preferably 0.5 mm or less, and more preferably 0.2 mm or less, the wire 88 is subjected to a pressing pressure when charged with explosives or the like. However, disconnection of the wire 88 can be prevented. The wire 88 is preferably gold or aluminum. This makes it possible to reliably supply current from the electrode pins 82 and 83 to the thin film bridge 85. The wire 88 has a wire diameter of usually 10 μm to 500 μm, preferably 20 μm to 500 μm, and more preferably 100 μm to 500 μm, so that the current can be supplied from the electrode pins 82 and 83 to the thin film bridge 85 more reliably. It becomes.

  The thin film bridge 85 and the wire 88 that joins the electrode pins 82 and 83 are connected so as to be stretched over the surface of the electrode pad 96 of the thin film bridge 85 as shown in FIG. At this time, as described above, since the thin film bridge 85 and the embolus 84 and the heads 95 of the electrode pins 82 and 83 are disposed in the recess 92 of the embolus 84 so as to be substantially uniform, the wire 88 is so-called laterally mounted. Can be joined. Further, in this case, as shown by a one-dot chain line (a line between A and A ′) in the drawing, the wire 88 is connected from one electrode pad 96 to the header metal portion 94 of the embolus 84, thereby grounding. Easy to take. The electrode pads 96 that are wire-bonded to the electrode pins 82 and 83 by the wires 88 are made of a laminate 93 in which reactive metals such as titanium and reactive insulators such as boron are alternately laminated. It is made of gold, aluminum, nickel, titanium or the like formed on the surface by thermal evaporation or the like.

The thin film bridge 85 may be any of a heating resistor, a reactive bridge using a reactive substance, a shock bridge, and the like. These are formed on a ceramic substrate such as Si substrate or Al ₂ O ₃ by a LIGA (Lithographie Galva-noformung, Abfprmung (fine processing technology using X-ray)) process or a known technique such as sputtering. In particular, the reactive bridge is preferable in that it operates stably with small energy.

  As shown in FIG. 6, the reactive thin film bridge 85 shown in this embodiment includes a reactive metal (for example, titanium) and a reactive insulator (for example, boron) alternately formed on the surface of the substrate 97. And the electrode pad 96 made of a conductive material such as a metal covering the surface. 5 and 6, the electrode pad 96 is positioned on the stacked body 93.

  Examples of the reactive metal used for the laminate 93 include aluminum, magnesium, zirconium and the like in addition to titanium. In addition to boron, the reaction insulator includes calcium, manganese, silicon, and the like. When the thin film bridge 85 having such a laminated body 93 is activated by a current flowing through the bridge portion, the reactive metal reacts with the reactive insulator and is released as hot plasma. And this plasma can ignite the loaded explosive efficiently.

  In the igniter 10 according to this embodiment, as shown in FIG. 4, first, after the explosives 86 and 87 are loaded in the first pipe body 89, the thin film bridge 85 is installed in the recess 92 formed in the embolus 84. Then, the electrode pins 82 and 83 are connected to the first tubular body 89 after being connected to the first tubular body 89 by wire bonding. At this time, even when the embolus 84 is pressed against the gunpowder 86 side, as described above, the thin film bridge 85 and the embolus 84 are embedded in the electrode pins 82 and 83 and the so-called sideways wires. Since it is connected by bonding, there is no fear of disconnection. In this way, after the embolus 84 is fitted to the first tubular body 89, the first tubular body 89 is inserted into the second tubular body 90 and insert-molded into the holder 98. Thus, it can be suitably used for an igniter for a gas generator used for various safety devices such as automobiles.

  In the igniter 10 configured as described above, when the current is supplied to the electrode pins 82 and 83, the thin film bridge 85 is activated, and the speed is about 1/10 that of the conventional power line. It is possible to efficiently ignite the explosives 86 and 87 in units of several μsec. Further, since the explosive can be efficiently ignited by the thermal energy generated in the thin film bridge 85, variations such as ignition delay can be reduced.

  The igniter 10 is not limited to the above-described embodiment, and the electrode pins 82 and 83 and the thin film bridge 85 can be reliably connected by wire bonding. An ASIC (Application Specific Integrated Circuit) or the like may be interposed between either one of them and the thin film bridge 85 and similarly connected by wire bonding.

  The gas generating agent 5 housed in such a gas generator is a non-azide composition, for example, composed of a fuel, an oxidizing agent, and an additive (binder, slag forming agent, combustion modifier). Can be used.

  Examples of the fuel include nitrogen-containing compounds. Examples of the nitrogen-containing compound include one or a mixture of two or more selected from triazole derivatives, tetrazole derivatives, guanidine derivatives, azodicarbonamide derivatives, hydrazine derivatives, urea derivatives, and ammine complexes.

  Specific examples of the triazole derivative include 5-oxo-1,2,4-triazole and aminotriazole. Specific examples of the tetrazole derivatives include tetrazole, 5-aminotetrazole, aminotetrazole nitrate, nitroaminotetrazole, 5,5′-bi-1H-tetrazole, 5,5′-bi-1H-tetrazole diammonium salt, 5 , 5'-azotetrazole diguanidinium salt and the like. Specific examples of the guanidine derivative include guanidine, nitroguanidine, cyanoguanidine, triaminoguanidine nitrate, guanidine nitrate, aminoguanidine nitrate, and guanidine carbonate. Specific examples of the azodicarbonamide derivative include azodicarbonamide and the like. Specific examples of the hydrazine derivative include carbohydrazide, carbohydrazide nitrate complex, oxalic acid dihydrazide, hydrazine nitrate complex, and the like. Examples of the urea derivative include biuret. Examples of the ammine complex include a hexaammine copper complex, a hexaammine cobalt complex, a tetraammine copper complex, and a tetraammine zinc complex.

  Among these nitrogen-containing compounds, one or more selected from tetrazole derivatives and guanidine derivatives are preferable, and nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, aminoguanidine nitrate, and guanidine carbonate are particularly preferable.

The mixing ratio of these nitrogen-containing compounds in the gas generating agent 5 varies depending on the number of carbon atoms, hydrogen atoms and other oxidized atoms in the molecular formula, but is usually preferably in the range of 20 to 70% by weight, and 30 to 60 A weight percent range is particularly preferred. Moreover, the absolute value of the compounding ratio of the nitrogen-containing compound varies depending on the kind of the oxidizing agent added to the gas generating agent. However, if the absolute value of the compounding ratio of the nitrogen-containing compound is larger than the theoretical amount of complete oxidation, the trace CO concentration in the generated gas increases. When it becomes below, the trace NOx density _| concentration in generated gas will increase. Therefore, the range in which the optimum balance between the two is maintained is most preferable.

  As the oxidizing agent, an oxidizing agent selected from at least one of nitrates, nitrites, and perchlorates containing a cation selected from alkali metals, alkaline earth metals, transition metals, and ammonium is preferable. Oxidizing agents other than nitrates, that is, oxidizing agents that are frequently used in the field of airbag inflators such as nitrite and perchlorate can also be used, but the number of oxygen in the nitrite molecule is reduced compared to nitrate, or Nitrate is preferred from the standpoint of reducing the production of fine powder mist that is easily released out of the bag. Examples of the nitrate include sodium nitrate, potassium nitrate, magnesium nitrate, strontium nitrate, phase-stabilized ammonium nitrate, basic copper nitrate, and the like, and strontium nitrate, phase-stabilized ammonium nitrate, and basic copper nitrate are more preferable.

The blending ratio of the oxidizing agent in the gas generating agent 5 varies in absolute value depending on the type and amount of the nitrogen-containing compound used, but is preferably in the range of 30 to 80% by weight, and particularly relates to the above-mentioned CO and NO _x concentrations. The preferred range is 40 to 75% by weight.

  Any binder can be used as long as it does not significantly adversely affect the combustion behavior of the gas generating agent. Examples of the binder include metal salts of carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, nitrocellulose, microcrystalline cellulose, guar gum, polyvinyl alcohol, polyacrylamide, starch and other polysaccharides. Derivatives, organic binders such as stearates, inorganic binders such as molybdenum disulfide, synthetic hydroxytalcite, acid clay, talc, bentonite, diatomaceous earth, kaolin, silica, and alumina.

  The blending ratio of the binder is preferably in the range of 0 to 10% by weight in the case of press molding, and is preferably in the range of 2 to 15% by weight in the extrusion molding. As the amount added increases, the fracture strength of the molded body increases. However, the number of carbon atoms and hydrogen atoms in the composition increases, the concentration of a trace amount of CO gas that is an incomplete combustion product of carbon atoms increases, and the quality of the generated gas decreases. Moreover, since the combustion of a gas generating agent is inhibited, use by the minimum amount is preferable. In particular, if the amount exceeds 15% by weight, the relative proportion of the oxidant needs to be increased, the relative proportion of the gas generating compound decreases, and it becomes difficult to establish a practical gas generator system.

  Moreover, a slag formation agent can be mix | blended as components other than a binder as an additive. The slag forming agent is added in order to facilitate filtration with the filter material 7 in the gas generator 1 due to the interaction with the metal oxide generated from the oxidant component in the gas generating agent.

  Examples of the slag forming agent include naturally occurring clay, synthetic mica, synthetic kaolinite, synthetic smectite and the like mainly composed of aluminosilicates such as silicon nitride, silicon carbide, acid clay, silica, bentonite and kaolin. Among these, artificial clay, talc which is a kind of hydrous magnesium silicate mineral, and the like can be mentioned. Among these, acidic clay or silica is preferable, and acidic clay is particularly preferable. The blending ratio of the slag forming agent is preferably in the range of 0 to 20% by weight, particularly preferably in the range of 2 to 10% by weight. If the amount is too large, the linear combustion rate is lowered and the gas generation efficiency is lowered. If the amount is too small, the slag forming ability cannot be sufficiently exhibited.

  As a preferable combination of the gas generating agent 5, a gas generating agent containing 5-aminotetrazole, strontium nitrate, synthetic hydrotalcite, and silicon nitride, or a gas containing guanidine nitrate, strontium nitrate, basic copper nitrate, and acid clay. Examples include generators.

  Moreover, you may add a combustion regulator as needed. As the combustion modifier, a metal oxide, ferrosilicon, activated carbon, graphite, or a chemical compound such as hexogen, octogen, 5-oxo-3-nitro-1,2,4-triazole can be used. The blending ratio of the combustion modifier is preferably in the range of 0 to 20% by weight, particularly preferably in the range of 2 to 10% by weight. If the amount is too large, the gas generation efficiency is lowered. If the amount is too small, a sufficient combustion rate cannot be obtained.

  The gas generating agent 5 having the above configuration is preferably a molded body by press molding or extrusion molding, more preferably an extrusion molded body, and the shape thereof is, for example, a pellet shape (generally, one shape of a pharmaceutical product). Tablet shape), a cylindrical shape, a cylindrical shape, a disk shape, or a hollow body shape in which both ends are closed. The cylindrical shape includes a cylindrical shape, and the cylindrical shape includes a single-hole cylindrical shape and a porous cylindrical shape. The hollow body shape with both ends closed includes a cylindrical shape with both ends closed. In addition, the state where both ends of the molded body of the gas generating agent 5 are closed refers to a state where the holes opened at both ends are closed by two forces from the outside to the inside. The hole may be either completely closed or not fully closed.

  An example of a method for producing the hollow body-shaped gas generating agent 5 with both ends closed will be described. The non-azide composition composed of the above-described nitrogen-containing compound, oxidizing agent, slag forming agent and binder is first mixed by a V-type mixer, a ball mill or the like. Furthermore, it mixes, adding water or a solvent (for example, ethanol), and can obtain the wet mass. Here, the wet state is a state having a certain degree of plasticity, and means a state containing preferably 10 to 25% by weight, more preferably 13 to 18% by weight of water or a solvent. Thereafter, the wet mass is directly extruded by an extruder (for example, a die and an inner hole pin provided at the outlet), and the outer diameter is preferably 1.4 mm to 4 mm, more preferably 1. It is 0.5 mm to 3.5 mm, and the inner diameter is preferably 0.3 mm to 1.2 mm, more preferably 0.5 mm to 1.2 mm. Thereafter, the hollow cylindrical molded body extruded by the extrusion molding machine is pressed at regular intervals to obtain a cylindrical molded body whose both ends are closed. Usually, after pressing the hollow cylindrical molded body at regular intervals, and then cutting it so as to be folded at each closed recess, it is usually dried in the range of 50 to 60 degrees for 4 to 10 hours, Usually, by performing drying in two stages of drying for 10 to 10 hours in the range of 105 to 120 degrees, a cylindrical gas generating agent having a space inside can be obtained with the end closed. . The length of the gas generant thus obtained is usually in the range of 1.5 to 8 mm, preferably in the range of 1.5 to 7 mm, more preferably in the range of 2 to 6.5 mm. .

Further, the linear burning rate of the gas generating agent is measured under a constant pressure condition and empirically follows the following Villele equation.
r = aP ⁿ
Here, r is a linear burning rate, a is a constant, P is pressure, and n is a pressure index. The pressure index n indicates a slope of a logarithmic plot of the pressure on the X axis with respect to the logarithm of the combustion speed on the Y axis.

The range of the preferable linear burning rate of the gas generating agent used in the gas generator according to the present embodiment is 3 to 60 mm / sec under 70 kgf / cm ² , more preferably 5 to 35 mm / sec, A preferable pressure index range is n = 0.90 or less, more preferably n = 0.75 or less, and particularly preferably n = 0.60 or less.

  Moreover, as a method for measuring the linear burning rate, a strand burner method, a small motor method, and a sealed pressure vessel method are generally cited. Specifically, after press-molding to a predetermined size, the burning rate is measured in a high-pressure vessel by a fuse cutting method or the like using a test piece obtained by applying a restrictor on the surface. At this time, the linear combustion rate is measured using the pressure in the high-pressure vessel as a variable, and the pressure index can be obtained from the above-mentioned Villele equation.

  Since the gas generating agent is formed of a non-azide-based gas generating agent, the raw materials used are those that are less harmful to the human body. Further, by selecting the fuel component and the oxidant component, the calorific value per mol of generated gas can be suppressed, and the gas generator can be reduced in size and weight.

As the enhancer agent 14 in contact with the gas generating agent 5 configured as described above, the enhancer agent 14 filled with the following composition generally used as the enhancer agent is used. Examples thereof include a metal powder typified by B / KNO ₃ , a composition containing an oxidizing agent, a composition containing a nitrogen-containing compound / oxidizing agent / metal powder, or a composition similar to the gas generating agent 5 described above. Examples of the nitrogen-containing compound include compounds that can be used as fuel components of the gas generating agent (aminotetrazole, guanidine nitrate, etc.). Examples of the oxidizing agent include nitrates such as potassium nitrate, sodium nitrate, and strontium nitrate. Examples of the metal powder include boron, magnesium, aluminum, magnalium (magnesium-aluminum alloy), titanium, zirconium, tungsten and the like. Preferable combinations include those containing 5-aminotetrazole, potassium nitrate, boron, guanidine nitrate, potassium nitrate, boron and the like. And as needed, you may also contain 0-10% of the binder for shaping | molding.

  Further, the shape of the enhancer agent 14 is preferably a molded body by press molding or extrusion molding, more preferably an extrusion molded body, and the shape thereof is a pellet shape (generally corresponding to a pharmaceutical tablet shape), a cylindrical shape, a cylinder shape Shape, disk shape, or hollow body shape with both ends closed. Examples of the cylindrical shape include a cylindrical shape, and examples of the cylindrical shape include a single-hole cylindrical shape and a porous cylindrical shape. The hollow body shape with both ends closed includes a cylindrical shape with both ends closed. The size of the enhancer agent 14 is preferably 1 mm or more.

  The gas generating agent 5 and the enhancer agent 14 are filled in the combustion chamber 6 in contact with each other. For this reason, since the difference of the distance of the enhancer agent 14 and the gas generating agent 5 by the difference in the filling condition of the gas generating agent 5 does not arise, the performance of the gas generator 1 can be stabilized. Further, by making the enhancer agent 14 preferably cylindrical, it is difficult to enter the gap of the gas generating agent 5 when the enhancer agent 14 is filled as compared with a powder or granule. Even after it is attached to the combustion chamber 6, it is possible to prevent them from mixing in the combustion chamber 6. For this reason, the performance of the gas generator can be made more reliable and stable.

In the above configuration, a method for manufacturing the gas generator will be described with reference to FIGS.
In FIG. 1, a cylindrical housing 4 provided with a gas discharge hole 11 is prepared.

  Next, head bolts 30a and 30b are welded to the outer periphery of the housing 4 at positions not covering the gas discharge holes 11 drilled in the housing 4 by welding or the like.

  Next, a filter 12, a gas generating agent 5, an enhancer agent 14, and a cushioning material 15 are filled in this order from one end 3 into the housing 4, and a holder 12 to which an igniter 10 is caulked and fixed is inserted. . A partition member 9 is provided between the filter material 7 and the gas generating agent 5 as necessary.

Next, a procedure for attaching the gas generator having the above configuration to the vehicle will be described.
First, the gas generator is inserted into an airbag (not shown) and a cover (not shown). The screw portions of the head bolts 30a and 30b pass through the airbag and a fastening hole (not shown) in the cover. This screw part is inserted into the airbag mounting hole of the vehicle and tightened with a nut, thereby completing the mounting and fixing to the vehicle.

Next, the operation of the gas generator in the above configuration will be described with reference to FIG.
When the collision sensor detects an automobile collision, the gas generator 1 sends a signal to the igniter 10 to ignite it. The flame of the igniter 10 ruptures and opens the cushion material 15, and then jets into the combustion chamber 6 to ignite the enhancer agent 14, thereby forcibly igniting and burning the gas generating agent 5. generate. The ignition combustion of the gas generating agent 5 sequentially shifts from the end 3 of the housing 4 to the filter material 7 side.

When combustion in the combustion chamber 6 proceeds and the combustion chamber 6 rises to a predetermined internal pressure, the high-temperature gas generated in the combustion chamber 6 passes through the holes 18 and enters the filter material 7, where slag collection and After cooling, it becomes a clean gas. This clean gas is discharged from the gas discharge hole 11.
Thereby, the sufficiently cooled clean gas discharged from the gas discharge hole 11 is directly introduced into the inside of an air belt, an air bag or the like, and is instantly expanded.

[Second Embodiment]
Next, the gas generator of 2nd Embodiment which concerns on this invention is demonstrated using FIG. 7, FIG. In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the description is abbreviate | omitted. The configuration of the second embodiment differs from the first embodiment in that the shape of the housing of the gas generator and the shape of the filter material are different. FIG. 7 shows the configuration of the gas generator 21 of the second embodiment, and FIG. 8 shows the shape of the housing. In the gas generator in which the other end 2 of the housing 24 has a rounded shape (bowl shape), the filter material 27 has a rounded shape at the other end 2, preferably the other end 2 is rounded. Those having a cylindrical or cylindrical shape are used. In FIG. 7, the other end portion 2 having a rounded columnar shape is illustrated. Since other points are the same as those of the first embodiment, description thereof is omitted.

[Third Embodiment]
Next, the gas generator of 3rd Embodiment which concerns on this invention is demonstrated using FIG. The gas generator 31 of the present embodiment is different in configuration from the gas generator 1 of the first embodiment, and the cylindrical housing 34 has a combustion chamber 6 filled with the gas generating agent 5 and a filter in which the filter material 7 is mounted. The filter material 37 is not partitioned into the chamber 8, and has a long cylindrical shape. The filter material 37 is disposed over substantially the entire length of the housing 34, and forms a combustion space S inside the cylindrical filter material 37.

  A plurality of gas discharge holes 11 are formed in the peripheral surface of the housing 34 so as to communicate from the combustion space S to an air bag (not shown). A plurality of gas discharge holes 11 are sequentially formed at predetermined intervals over the axial direction from the lid member 39 provided on one end side of the housing 34 to the other end portion 2. Head bolts 30a and 30b as attachment members for attachment to the vehicle are welded to the housing 34 in the same axial direction on the peripheral surface so as not to cover the gas discharge holes 11 drilled in the housing 34. It is welded by etc. The plurality of gas discharge holes 11 are formed such that the opening density of the gas discharge holes 11 increases from a position where the head bolts 30a and 30b are attached to a portion that is separated from the circumferential direction of the housing 34 by an angle of 180 degrees. Preferably it is. The increase in the opening density of the gas discharge holes 11 is to increase the diameter of one gas discharge hole 11 as it goes from the mounting position of the mounting member toward a portion that is separated by an angle of 180 degrees in the circumferential direction of the housing 34. You may go on. Further, when the plurality of gas discharge holes 11 have the same diameter, the number of the gas discharge holes 11 is increased and increased from the mounting position of the mounting member toward a portion that is separated by an angle of 180 degrees in the circumferential direction of the housing 34. Also good.

  The pellet-shaped gas generating agent 5 is accommodated in the combustion space S inside the cylindrical filter material 37.

  The igniter 38 includes an igniter 36 that is ignited by a collision detection signal from a collision sensor (not shown), and a granular enhancer 14 that is ignited by the ignition of the igniter 36. The igniter 36 is caulked and fixed in a sealed state in a storage hole 33 formed in the lid member 39. The storage hole 33 communicates with the internal space of the tubular filter material 37. The enhancer agent 14 is accommodated in the hooked cap 35.

  The protruding portion 35 a of the hooked cap 35 is inserted into the internal space of the filter material 37. Further, the protruding portion 35 a of the hooked cap 35 has a through hole 35 b through which the flame of the enhancer agent 14 is ejected into the filter material 37. The flange portion 35c of the flanged cap 35 extends to the inner periphery of the housing 34, and is sandwiched between the lid member 39 and the filter material 37, thereby sealing the combustion space S of the housing 34 from the outside.

  Next, the operation of the gas generator 31 of the third embodiment having the above configuration will be described with reference to FIG. When the collision sensor detects an automobile collision, the enhancer agent 14 is ignited by igniting the igniter 36 of the igniter 38. The ignition flame of the enhancer agent 14 is injected into the combustion space S from the through hole 35b of the flanged cap 35, and burns the gas generating agent 5 from the lid member 39 side toward the other end portion 2, thereby causing a high temperature. Generate gas.

  The high-temperature gas generated in the combustion space S flows into the filter material 37, where it becomes clean gas through slag collection and cooling. This clean gas is discharged from the gas discharge hole 11. As a result, the sufficiently cooled clean gas discharged from the gas discharge hole 11 is directly introduced into the interior of the air belt, the air bag, etc., and instantly expands. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

[Fourth Embodiment]
Next, the gas generator of 4th Embodiment which concerns on this invention is demonstrated using FIG. The difference of the configuration of the fourth embodiment from the third embodiment is the configuration of the filter material and the configuration of the lid member 39.

  The filter material 47 includes two cylindrical filter units 47 </ b> A and 47 </ b> B connected in the axial direction between the other end 2 of the housing 44 and the lid member 49. The filter unit 47 </ b> A is located on the other end 2 side of the housing 44. The filter unit 47B is disposed on the lid member 49 side continuously to the filter unit 47A. Further, the filter material 47 changes the gas passage performance in the axial direction of the housing 44 by making the filter unit 47B difficult to pass the high-temperature gas through the filter unit 47A.

  The lid member 49 is fixed by caulking by bending one end 3 of the housing 44 inward in the diameter. Since other points are the same as those of the third embodiment, description thereof is omitted.

[Fifth Embodiment]
Next, the gas generator of 5th Embodiment based on this invention is demonstrated using FIG. The difference of the configuration of the fifth embodiment from the third embodiment and the fourth embodiment is the configuration of the filter material.

  The filter member 57 includes three cylindrical filter units 57A, 57B, and 57C that are connected in the axial direction between the other end 2 of the housing 44 and the lid member 49. The filter unit 57 </ b> A is located on the other end 2 side of the housing 44. The filter unit 57B is arranged at the center in the axial direction of the housing 44 continuously to the filter unit 57A. The filter unit 57C is arranged on the lid member 49 side continuously to the filter unit 57B. Further, the filter member 57 has a structure in which the filter unit 57C has a structure in which high-temperature gas cannot easily pass through the filter unit 57B, and the filter unit 57B has a structure in which high-temperature gas does not easily pass through the filter unit 57A. The gas passage performance is changed in three stages depending on the direction. Since other points are the same as those of the third embodiment and the fourth embodiment, description thereof is omitted.

[Sixth Embodiment]
Next, the gas generator of 6th Embodiment which concerns on this invention is demonstrated using FIG. The configuration of the sixth embodiment is different from the first embodiment in the configuration of the filter material, the housing, and the head bolt.

  The housing 64 has a configuration in which the space 68 on the other end 2 side has a reduced diameter, and the space 68 communicates with the outside through the gas discharge hole 11. In addition, the filter material 67 is not cylindrical but has a core, is in the middle of the housing 64, and is fixed between the partition member 76 and the partition member 79. The partition member 79 partitions the filter chamber 8 clogged with the filter material 67 and the combustion chamber 6, has a hole 74, and biases the filter material 67 in the direction of the other end portion 2. The partition member 76 partitions the space 68 and the filter chamber 8, has a hole 73 and a seal member 72 that seals the hole 73, and is fixed by crimping to a reduced diameter portion of the housing 64, and a filter material And a partition plate 76b serving as a leaf spring for urging 67 in the direction of one end 3. The gas generating agent 5 and the enhancer agent 14 are separated by a wire mesh 65 so that they do not cross each other.

  The headed bolt 60a has a threaded portion longer than the headed bolt 60b welded to the housing 64, and passes through the two gas discharge holes 11 drilled at intervals of 180 degrees. Thereby, the headed bolt 60a is engaged with the airbag module with the housing 64 interposed therebetween to suitably fix the housing 64, and does not require any processing such as welding. The diameter of the screw portion of the head bolt 60a is substantially the same as the diameter of the gas discharge hole 11, and the housing 64 is preferably fixed without wobbling in the gas discharge hole 11. Further, it is preferable that the head of the head bolt 60a does not protrude from the maximum diameter φ1 of the housing 64 which is not reduced in diameter, and does not increase the outer shape of the gas generator. According to this configuration, since the volume of the filter material 67 is larger than that of the first embodiment, the effect of collecting and cooling the slag of the filter can be made remarkable, and the headed bolt is penetrated through the gas discharge hole. It can be easily engaged with the housing at a lower cost. The head bolt 60a may be welded to the housing 64 by welding or the like. Since other points are the same as those of the first embodiment, description thereof is omitted.

[Seventh Embodiment]
Next, the gas generator of 7th Embodiment which concerns on this invention is demonstrated using FIG. The configuration of the seventh embodiment is different from that of the sixth embodiment in that the filter material 67 is fixed by caulking the caulking portion 75 from the outside of the housing 74 and the partition member 79 is not used. Since the other points are the same as in the sixth embodiment, description thereof is omitted.

  As described above, the gas generator of the present invention has a configuration in which the head bolt, which is an attachment member, is directly provided on the housing of the gas generator without impairing the original function of the gas generator. As a result, the airbag module can be attached to the vehicle without using an attachment member that has conventionally been required separately. In addition, the work of fixing the airbag module to the vehicle can be done by only one work of tightening the nut to the threaded portion of the head bolt, and the work efficiency is extremely good. Further, in the production of the gas generator, the headed bolt as an attachment member is attached to the housing before filling with a chemical such as a gas generating agent, so that it is safe in terms of work.

Moreover, although this invention was demonstrated based on suitable embodiment, this invention can be changed in the range which does not exceed the meaning. That is, the headed bolt may not be welded to the housing by welding. Moreover, the curved part does not need to be formed in the head of the headed bolt. Even in this case, if there is no problem in the bonding strength between the headed bolt and the housing, it can be suitably used as a gas generator.
Furthermore, although the pyro-type gas generator has been described as an example in the above embodiment, the present invention can also be suitably applied to a hybrid-type gas generator.

It is sectional drawing of the gas generator of 1st Embodiment which concerns on this invention. It is a front view which shows the external appearance of the gas generator of 1st Embodiment. The back view is omitted because it appears symmetrically with the front view. It is a bottom view which shows the external appearance of the gas generator of 1st Embodiment. It is a top view which shows the external appearance of the gas generator of 1st Embodiment. It is a right view which shows the external appearance of the gas generator of 1st Embodiment. It is a left view which shows the external appearance of the gas generator of 1st Embodiment. It is a figure which shows the external appearance of the headed bolt which concerns on this invention. It is sectional drawing of the igniter used for the gas generator of 1st Embodiment. It is a figure which shows the principal part plane which expanded a part of FIG. It is a figure which shows the A-A 'line cross section in FIG. It is sectional drawing of the gas generator of 2nd Embodiment which concerns on this invention. It is a front view which shows the external appearance of the gas generator of 2nd Embodiment. The back view is omitted because it appears symmetrically with the front view. It is a bottom view which shows the external appearance of the gas generator of 2nd Embodiment. It is a top view which shows the external appearance of the gas generator of 2nd Embodiment. It is a right view which shows the external appearance of the gas generator of 2nd Embodiment. It is a left view which shows the external appearance of the gas generator of 2nd Embodiment. It is sectional drawing of the gas generator of 3rd Embodiment which concerns on this invention. It is sectional drawing of the gas generator of 4th Embodiment which concerns on this invention. It is sectional drawing of the gas generator of 5th Embodiment which concerns on this invention. It is sectional drawing of the gas generator of 6th Embodiment which concerns on this invention. It is sectional drawing of the gas generator of 7th Embodiment which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas generator 2 Other end part 3 One end part 4 Housing 5 Gas generating agent 6 Combustion chamber 7 Filter material 8 Filter chamber 9 Partition member 10 Igniter 11 Gas discharge hole 12 Holder 13 Shaft end part 14 Enhancer agent 15 Cushion material 16 Seal Member 18 Hole 19 Space 20 Cylindrical portion 30a, 30b Mounting member (head bolt)

Claims (3)

A tubular housing (4);
A gas generating agent (5) filled in the housing (4) and generating a high temperature gas by combustion;
A filter material (7) mounted in the housing (4);
A gas generator (1) having an igniter (10) attached to one end (3) of the housing (4) and igniting and burning the gas generating agent (5) in the housing (4). In
A gas generator characterized in that a headed bolt (30a, 30b) for mounting on a vehicle is provided directly on the housing (4).   The gas generator according to claim 1, wherein the headed bolts (30a, 30b) are welded to the housing (4) by welding.   The gas generator according to claim 1 or 2, wherein a curved portion (101) having a curvature (R1) of the same degree as the outer peripheral surface of the housing (4) is formed at a head of the headed bolt (30a, 30b). .

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