JP2021138190A - Gas generator - Google Patents

Abstract

To obtain a gas generator which has a holder that can assemble a component to an inside part in the state that the same has a strength easily and sufficiently compared to a conventional one.SOLUTION: A gas generator 100 includes: a housing 10; a holder 20 attached to one opening end of the housing 10; and a closing member 12 which is attached to the other end of the housing 10 so as to close the other opening end of the housing 10. An actuating gas generation chamber 17 in which a gas generating agent 30 is accommodated, a filter chamber 18 in which a filter 40 is accommodated, and an ignition chamber 19 are provided in an internal space of the housing 10. The holder 20 has: a first formation part 20a having a holding part 26 which holds an igniter 50 inside the housing 10; and a second formation part 20b having a fitting part 21 which can fit a connector for electrically conducting to the igniter 50 via a retainer 60 on a side opposite to a holding position of the igniter 50. The holder is fixed to one end part on the ignition chamber 19 side in the housing 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas generator incorporated in an airbag device as an occupant protection device mounted on an automobile or the like, and more specifically, to a so-called cylinder type gas generator having a long cylindrical outer shape.

Conventionally, in a cylinder type gas generator, a closing member called a holder for closing one end of a housing is often provided (see, for example, Patent Document 1 below).

U.S. Patent Application Publication No. 2009/0114109

In Patent Document 1, the entire holder is formed by cutting a fitting portion for attaching a female connector inside a metal holder and assembling parts using this inner portion. Cutting the inside has been a complicated process of generating cutting chips and pressing the cutting blade inward. In particular, when processing is performed inside the holder, the processing depth tends to be limited. In addition, when it is desired to increase the thickness of the parts to be assembled in order to increase the strength, it may interfere with other parts.

Therefore, an object of the present invention is to provide a gas generator having a holder capable of assembling parts to an inner portion in a state of having sufficient strength more easily than before without going through a complicated processing process. Is to be.

(1) The gas generator of the present invention houses a working gas generation chamber in which a working gas is generated by burning a gas generating agent and a filter through which the working gas generated in the working gas generation chamber passes. A long cylindrical housing containing a filter chamber and an igniting agent are contained therein, and the gas generating agent in the working gas generating chamber is ignited by being arranged at one end in the axial direction of the housing. A gas generating agent igniting means capable of burning, a substantially tubular first forming portion having a holding portion for holding the gas generating agent igniting means on the inner side of the housing, and the gas generating agent igniting means. On the side opposite to the holding position, it has a substantially tubular second forming portion having a fitting portion into which a connector for energizing the gas generating agent ignition means can be fitted, and the working gas generation in the housing. A holder fixed to one end on the chamber side is provided, and a plurality of gas jets for ejecting working gas that has passed through the filter to the outside are provided on the peripheral wall portion of the portion of the housing that defines the filter chamber. An outlet is provided, and the holder is provided in a first engaging portion provided in at least a part of the outer wall portion of the first forming portion, and a second holder provided in at least a part of the outer wall portion of the second forming portion. By engaging the engaging portion, the first forming portion and the second forming portion are connected to each other.

(2) In the gas generator of the above (1), it is preferable that the second forming portion is a resin molded product.

(3) In the gas generator according to (1) or (2), the second forming portion is positioned at one end of the housing used when fixing the holder to one end of the housing. It is preferable that the positioning portion for the purpose is formed in at least a part of the outer peripheral portion.

According to each of the above configurations, it is possible to provide a gas generator having a holder capable of assembling parts to an inner portion in a state of having sufficient strength more easily than before without going through a complicated processing process. can.

It is a schematic diagram which shows the internal structure of the gas generator which concerns on 1st Embodiment of this invention which a part is shown in the cross section. It is a partially enlarged sectional view of FIG. It is an exploded view of the holder of FIG. 1, and is the figure which showed the connecting direction. It is a schematic diagram which shows the internal structure of the gas generator which concerns on 2nd Embodiment of this invention which a part is shown in the cross section. It is a partially enlarged sectional view of FIG. It is an exploded view of the holder of FIG. 4, and is the figure which showed the connecting direction. It is the figure which showed the state of the positioning of the end of the housing of the gas generator of FIG. 4 simply.

<First Embodiment>
Hereinafter, the internal structure of the cylinder-type gas generator according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3.

(Structure of gas generator 100)
The gas generator 100 has a long substantially columnar outer shape, and closes the housing 10, the holder 20 attached to one open end of the housing 10, and the other open end of the housing 10. Includes a closing member 12 attached to the other end of the housing 10.

The housing 10 is made of a long cylindrical member having openings at both ends in the axial direction. The closing member 12 is made of a disk-shaped member having a predetermined thickness, and has an annular groove portion 13 for fixing caulking described later on its peripheral surface. The annular groove portion 13 for fixing the caulking is formed so as to extend in the circumferential direction on the peripheral surface of the closing member 12. Further, a gas outlet 11 is provided on the peripheral wall near the end on the side where the closing member 12 of the housing 10 is attached. The gas outlets 11 are holes for ejecting the gas generated inside the gas generator 100 to the outside, and are provided in plurality along the circumferential direction and the axial direction of the housing 10.

The closing member 12 is made of a metal such as stainless steel, steel, an aluminum alloy, or a stainless alloy, and is made of a disk-shaped member having a predetermined thickness. Then, with a part of the closing member 12 inserted in one open end of the housing 10, the peripheral wall of the housing 10 corresponding to the annular groove portion 13 provided on the peripheral surface of the closing member 12 is radially inside. The closing member 12 is caulked and fixed to the housing 10 by reducing the diameter to (caulking) and engaging the annular groove portion 13.

As shown in FIG. 3, the holder 20 has a first forming portion 20a having a holding portion 26 for holding the igniter 50 on the inner side of the housing 10, and an igniter 20 on the side opposite to the holding position of the igniter 50. It has a connector for energizing 50 and a second forming portion 20b having a fitting portion 21 that can be fitted via a retainer 60, and is fixed to one end of the housing 10 on the ignition chamber 19 side. .. Further, the holder 20 has an annular concave portion-shaped first engaging portion 24 provided on the outer wall portion of the first forming portion 20a, and an annular convex portion-shaped second engaging portion provided on the outer wall portion of the second forming portion 20b. By engaging the joint portion 25, the first forming portion 20a and the second forming portion 20b are connected to each other.

The first forming portion 20a is made of a metal such as stainless steel, steel, aluminum alloy, or stainless alloy, and is made of a tubular member having a fitting portion 28 extending in the same direction as the axial direction of the housing 10. .. Further, the first forming portion 20a is a positioning portion 23 used for positioning an annular groove portion 22 for caulking fixing described later and an end portion of the housing 10 before caulking fixing at a predetermined position on the outer peripheral surface thereof. And have. The annular groove portion 22 for fixing the caulking is formed so as to extend in the circumferential direction on the outer peripheral surface of the first forming portion 20a. A peripheral wall of the housing 10 corresponding to the annular groove 22 provided on the outer peripheral surface of the first forming portion 20a with a part of the first forming portion 20a interpolated into the other open end of the housing 10. The first forming portion 20a is caulked and fixed to the housing 10 by reducing (caulking) the diameter inward in the radial direction and engaging the annular groove portion 22 with the annular groove portion 22.

Further, as shown in FIG. 3, the second forming portion 20b has a tubular portion 29 that fits into the fitting portion 28 of the first forming portion 20a, and is a member molded of resin. The second forming portion 20b is formed by injection molding, and a resin material having excellent heat resistance, durability, corrosion resistance and the like after curing is preferably selected. Specifically, it is represented by a thermosetting resin typified by an epoxy resin or the like, a polybutylene terephthalate resin, a polyethylene terephthalate resin, a polyamide resin (for example, nylon 6 or nylon 66), a polypropylene sulfide resin, a polypropylene oxide resin or the like. It is possible to use a thermoplastic resin or the like. When a thermoplastic resin is selected as a raw material, it is preferable to include glass fiber or the like as a filler in order to improve the mechanical strength of the holding portion 26 after molding.

As shown in FIG. 1, an igniter 50 as an ignition means for the gas generating agent 30 is arranged at one end in the axial direction of the housing 10 (that is, a portion closer to the holder 20). The igniter 50 and the holder 20 for fixing the igniter 50 have a function as an ignition means for generating a flame for burning the granular gas generating agent 30 described later.

As shown in FIGS. 2 and 3, the igniter 50 is interpolated and caulked and fixed in the holding portion 26 of the first forming portion 20a. More specifically, the first forming portion 20a has a caulking portion 27 at the end of the housing 10 on the side facing the space inside, and the igniter 50 is inserted into the holding portion 26 to form a cylindrical member. By crimping the crimped portion 27 while being attached to the first forming portion 20a via the 51, the igniter 50 is sandwiched between the first forming portions 20a and the igniter 50 is fixed to the first forming portion 20a. Has been done. Here, the tubular member 51 is a directional member for directing the direction of the flame emitted from the tip end portion of the igniter 50 toward the working gas generation chamber 17.

More specifically, the igniter 50 includes a base frame through which a pair of terminal pins 52 are inserted and held, and a squib cup 50a mounted on the base frame, and the terminals inserted in the squib cup 50a. A resistor (bridge wire) is attached so as to connect the tip of the pin 52, and the squib cup 50a is filled with an igniter so as to surround the resistor or to be in contact with the resistor. Nichrome wire or the like is generally used as the resistor, and ZPP (zirconium / potassium perchlorate), ZWPP (zirconium / tungsten / potassium perchlorate), lead styphnate or the like is generally used as the ignition agent. The squib cup 50a may be filled with not only the igniter but also a igniter, but the squib cup 50a may be filled with a igniter, but the squib cup 50a may be filled with a metal / oxidant typified by boron / potassium nitrate or the like. , A composition composed of titanium hydride / potassium perchlorate, a composition composed of boron / 5-aminotetrazole / potassium nitrate / molybdenum trioxide, or the like is used. The squib cup is generally made of metal or resin.

When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 52. When a predetermined amount of electric current flows through the resistor, Joule heat is generated in the resistor, and the ignition charge starts combustion in response to this heat. The high temperature flame generated by the combustion causes the squib cup 50a containing the ignition charge to burst. The time from when a current flows through the resistor until the igniter 50 operates is 2 milliseconds or less when a nichrome wire is used for the resistor.

As shown in FIG. 1, in the internal space of the housing 10, a working gas generation chamber 17 in which a container 34 containing a gas generating agent 30 is loaded, a filter chamber 18 in which a filter 40 is housed, and a winding are wound. An ignition chamber 19 in which the spring 53 is housed and an ignition chamber 19 are provided. The working gas generation chamber 17 and the filter chamber 18 are partitioned by a partition member 31.

The accommodator 34 has a bottomed cylindrical portion 34a and a lid portion 34b, and internally has a gas generating agent 30 and an auto-ignition (AI) function that automatically ignites regardless of the operation of the igniter 50. The AI agent 32 and the AI agent 32 are arranged. The lid portion 34b and the tip portion of the igniter 50 are arranged apart from each other so as to have a predetermined distance. This makes it easier for the squib cup 50a to open when the igniter 50 operates.

As shown in FIG. 1, the gas generating agent 30 is disposed between the winding spring 35 and the cover member 33, and is ignited by a flame generated by being ignited by the igniter 50 and burned to produce a gas. It is an integrally molded product that generates. Further, the gas generating agent 30 is generally formed as a molded body containing a fuel, an oxidizing agent and an additive. As the fuel, for example, a triazole derivative, a tetrazole derivative, a guanidine derivative, an azodicarbonamide derivative, a hydrazine derivative, or a combination thereof is used. Specifically, for example, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole and the like are preferably used. Examples of the oxidizing agent include basic metal hydroxides such as basic copper nitrate and basic copper carbonate, perchlorates such as ammonium perchlorate or potassium perchlorate, alkali metals, and alkaline earth metals. , Transition metals, nitrates containing cations selected from ammonia, etc. are used. As the nitrate, for example, sodium nitrate, potassium nitrate and the like are preferably used. In addition, examples of the additive include a binder, a slag forming agent, a combustion adjusting agent, and the like. As the binder, for example, a cellulose derivative such as hydroxypropylene methyl cellulose, a metal salt of carboxymethyl cellulose, an organic binder such as stearate, synthetic hydroxytalcite, and an inorganic binder such as acidic clay can be preferably used. As the slag forming agent, silicon nitride, silica, acidic white clay and the like can be preferably used. Further, as the combustion modifier, metal oxide, ferrosilicon, activated carbon, graphite and the like can be preferably used.

As shown in FIG. 1, the winding spring 35 is formed by spirally winding so as to resemble a truncated cone shape as a whole. Further, one end of the winding spring 35 is in contact with the lid portion 34b, and the other end portion formed in a spiral shape is in contact with the gas generating agent 30 to urge the gas generating agent 30 with an elastic force. It is provided to do so. By this urging, the gas generating agent 30 is fixed in the housing 10 so as to be sandwiched between the winding spring 53 and the cover member 33 described later. Further, the winding spring 35 has a truncated cone shape from the igniter 50 side to the gas generator 30 side as a whole, so that the direction of the flame emitted from the igniter 50 can be easily directed to the gas generator 30 side. be able to.

Since the AI agent 32 having an AI function automatically ignites at a temperature lower than that of the gas generator 30, in the unlikely event that a fire or the like occurs in a vehicle or the like equipped with an airbag device or the like in which the gas generator 100 is incorporated, It is possible to prevent the induction of abnormal operation of the gas generator 100 due to heating from the outside. Further, the AI agent 32 is housed in the container 34 in a state of being sandwiched between the bottom portion of the bottomed tubular portion 34a and the cover member 33. The cover member 33 is provided with a plurality of holes.

As shown in FIGS. 1 and 2, the partition member 31 has a substantially bowl shape, and a cut line (score) is provided near the center of the bottom portion so as to be easily broken when a predetermined pressure is applied. There is. The bottom of the partition member 31 is a flat circular one that is directly in contact with one of the flat ends of the gas generating agent 30, and has an inner diameter smaller than the inner diameter of the housing 10, but is a container. It is larger than the inner diameter of 34. Further, by covering the periphery of the bottom of the container 34 with a partition member 31, a gap (heat insulating layer) is formed between the inner wall of the housing 10 and the outer circumference of the container 34. As a result, in the unlikely event that a fire or the like occurs in a vehicle or the like equipped with an airbag device or the like in which the gas generator 100 is incorporated, the gas generator 30 will burn before the automatic ignition of the AI agent 32. It can be prevented more.

As shown in FIG. 1, the filter chamber 18 communicates with the outside through the gas outlet 11 provided on the peripheral wall of the housing 10 described above. Further, in the filter chamber 18, a filter 40 made of a cylindrical member having a substantially cylindrical space 40a in the center is housed. Further, if the filter 40 made of the cylindrical member is used in this way, the flow resistance of the working gas flowing through the filter chamber 18 during operation can be suppressed to a low level, and efficient gas flow is possible. As the filter 40, for example, a wire rod made of a metal such as stainless steel or steel, a wire rod wound with a net material, or a filter 40 compacted by press working is used. Specifically, a knitted wire mesh, a plain weave wire mesh, an aggregate of crimp-woven metal wire rods, or the like is used. The filter 40 functions as a cooling means for cooling the gas by taking away the high-temperature heat of the gas when the gas generated in the working gas generation chamber 17 passes through the filter 40, and is included in the gas. It also functions as a removing means for removing slag and the like. Here, as a modification of the filter 40, a filter having a maze-shaped flow path formed by combining substantially cylindrical or mortar-shaped parts made of metal may be used. As a result, the course of the working gas can be changed in various directions, so that the gas can be cooled and the slag can be removed.

As shown in FIG. 1, the ignition chamber 19 is provided with a winding spring 53 along the inner wall of the housing 10 facing the outer circumference of the tubular member 51. The winding spring 53 urges the container 34 to be pressed against the partition member 31 from the side of the first forming portion 20a.

A female connector (not shown) is attached to the second forming portion 20b. This female connector is a portion to which the male connector of the harness that transmits a signal from the collision detecting means provided separately from the gas generator 100 is connected. A retainer 60 is attached to the female connector. The retainer 60 is attached to prevent the cylinder type gas generator 100 from malfunctioning due to electrostatic discharge or the like during transportation of the gas generator 100, and is attached at the stage of assembling to the airbag device. When the male connector of the harness is inserted into the female connector, the contact with the terminal pin 52 is released.

Next, the operation of the gas generator 100 described above during operation will be described. When a vehicle equipped with an airbag device incorporating the gas generator 100 in the present embodiment collides, the collision is detected by a collision detecting means separately provided in the vehicle, and the igniter 50 is based on this. Works. When the igniter 50 is activated, the pressure inside the igniter 50 rises due to the combustion of the igniter, which causes the tip of the squib cup 50a of the igniter 50 to burst, and the flame is externally (ignited) from the tip of the squib cup 50a of the igniter 50. It flows out to room 19).

The flame flowing in this way cleaves the lid portion 34b of the container 34, and further ignites and burns the gas generating agent 30 in the container 34 to generate a large amount of gas. Combustion of the gas generating agent 30 raises the pressure in the working gas generation chamber 17, which causes the bottom portion of the bottomed tubular portion 34a and the partition member 31 to be cleaved, and the gas flows into the filter chamber 18. Since the folded portion of the substantially bowl-shaped partition member 31 can prevent gas from flowing between the filter 40 and the inner wall of the housing 10, the gas is discharged to the outside without passing through the filter 40. It prevents it from being done. In this way, the gas that has flowed into the filter chamber 18 is cooled to a predetermined temperature via the filter 40. A large amount of cooled gas is ejected from the gas outlet 11 to the outside of the gas generator 100. The gas ejected from the gas outlet 11 is guided to the inside of the airbag to expand and deploy the airbag.

(Main features of gas generator 100)
According to the present embodiment, the second engaging portion 25 provided on the outer wall portion of the second forming portion 20b engages with the first engaging portion 24 provided on the outer wall portion of the first forming portion 20a. As a result, the first forming portion 20a and the second forming portion 20b are connected. That is, it is not necessary to perform complicated processing for assembling the part (second forming portion 20b) on the inner portion of the first forming portion 20a. Therefore, according to the present embodiment, the gas generator 100 having a holder capable of assembling parts to the inner portion in a state where it is easier and has sufficient strength than the conventional one without going through a complicated processing process. Can be provided.

Conventionally, the fitting portion 21 for attaching the female connector to the inside of the metal holder 20 has been cut, but cutting the inside of the holder 20 is complicated to generate cutting chips and press the cutting blade inward. It was a process. On the other hand, in the present invention, cutting the outside of the first forming portion 20a, which requires strength, makes it easier to remove cutting chips and further makes it easier to press the cutting blade, so that the process becomes easier.

Further, since the second forming portion 20b is molded from resin, it can be shaped according to the application. Further, by producing the mold of the second forming portion 20b, various shapes can be easily and mass-produced, so that the cost can be lowered as compared with the conventional case. Therefore, according to the present embodiment, it is possible to provide the gas generator 100 having the holder 20 having high versatility.

Further, the resin-made second forming portion 20b is colored with a resin, a filler, a pigment, or a dye to facilitate identification of the size (number) of the connector material such as the pore diameter, the type of the connector material, and the like. Can be done. As a result, the size, type, etc. of the connector material can be easily visually identified and determined without using a magnifying glass or the like, and the confirmation work at the time of assembly can be efficiently performed.

<Second Embodiment>
Hereinafter, the internal structure of the cylinder-type gas generator according to the second embodiment of the present invention will be described with reference to FIGS. 4 to 7. Unless otherwise specified, reference numerals having the same last two digits may be used for the same parts as those in the first embodiment, and the description may be omitted. Further, in this embodiment, unless otherwise specified, the same parts as those in the above embodiment are used.

(Structure of gas generator 200)
The gas generator 200 is different from the first embodiment in that the holder 120 is mainly used. Hereinafter, a specific description will be given.

The holder 120 includes a first forming portion 120a and a second forming portion 120b. The first forming portion 120a and the second forming portion 120b have a first engaging portion 124 having an annular concave shape of the first forming portion 120a and a second engaging portion 125 having an annular convex portion shape of the second forming portion 120b. By engaging, they are connected to form the holder 120.

The first forming portion 120a and the first forming portion 20a of the first embodiment are mainly provided with no positioning portion used for positioning the end portion of the housing 110 before caulking and fixing. It's different.

The second forming portion 20b is mainly provided with a positioning portion 123 used for positioning the end portion of the housing 110 before caulking and fixing (see FIGS. 6 and 7), and the first forming portion 20b is formed. It differs from the second forming portion 20b of the first embodiment in that the second engaging portion 125 is caulked and fixed together with the annular groove portion 122 of the portion 120a. Note that FIG. 7 is a diagram simply showing how the end of the housing 110 is positioned before the end of the housing 110 is caulked and fixed to the holder 120.

According to the present embodiment, the same actions and effects as those of the first embodiment can be obtained. Further, since the positioning portion 123 is formed on the second forming portion 20b made of resin, even if the design is changed according to the application, it can be easily manufactured by manufacturing a mold, and mass production is also possible.

Although the embodiments of the present invention have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present invention is shown by the scope of claims rather than the description of the embodiment described above, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

For example, if the first engaging portion 24 and the second engaging portion 25 of the first embodiment are engaged with each other to connect the first forming portion 20a and the second forming portion 20b. The first engaging portion 24 and the second engaging portion 25 may have any shape. That is, the first engaging portion 24 is provided on at least a part of the outer wall portion of the first forming portion 20a, and the second engaging portion 25 is provided on at least a part of the outer wall portion of the second forming portion 20b. It may be provided so that the first forming portion 20a and the second forming portion 20b are connected by engaging the first engaging portion 24 and the second engaging portion 25. As an example of this, the first engaging portion 24 is not an annular recess shape as in the first embodiment, but is one or more hole-shaped recesses, and the second engaging portion 25 that fits into the recesses is It may be formed in the shape of a hook. The same applies to the second embodiment.

10, 110 Housing 11, 111 Gas outlet 12, 112 Closing member 13, 113 Circular groove 17, 117 Working gas generation chamber 18, 118 Filter chamber 19, 119 Ignition chamber 20, 120 Holder 20a, 120a First forming portion 20b, 120b Second forming portion 21, 121 Fitting portion 22, 122 Annular groove portion 23, 123 Positioning portion 24, 124 First engaging portion 25, 125 Second engaging portion 26, 126 Holding portion 27, 127 Caulking portion 28 Fitting Part 29 Cylindrical part 30, 130 Gas generating agent 31, 131 Partition member 32, 132 AI agent 33, 133 Cover member 34, 134 Incubator 34a, 134a Bottomed tubular part 34b, 134b Lid part 35, 135 Winding spring 40 , 140 Filter 40a, 140a Space 50, 150 Ignition 50a, 150a Squib cup 51, 151 Cylindrical member 52, 152 Terminal pin 53, 153 Winding spring 60, 160 Retainer 100, 200 Gas generator

Claims (3)

A length including a working gas generation chamber in which a working gas is generated by burning a gas generating agent and a filter chamber in which a filter through which the working gas generated in the working gas generation chamber passes is housed. With a cylindrical housing
A gas generator igniting means that contains an igniter, is arranged at one end in the axial direction of the housing, and can ignite and burn the gas generator in the working gas generation chamber.
The gas generating agent igniting means is provided at a substantially cylindrical first forming portion having a holding portion for holding the gas generating agent igniting means on the inner side of the housing and on a side opposite to the holding position of the gas generating agent igniting means. A holder having a substantially cylindrical second forming portion having a fitting portion into which a connector for energizing the housing can be fitted, and being fixed to one end of the housing on the working gas generation chamber side.
With
A plurality of gas ejection ports for ejecting working gas that has passed through the filter to the outside are provided on the peripheral wall portion of the portion of the housing that defines the filter chamber.
In the holder, a first engaging portion provided on at least a part of the outer wall portion of the first forming portion is engaged with a second engaging portion provided on at least a part of the outer wall portion of the second forming portion. A gas generator characterized in that the first forming portion and the second forming portion are connected by being combined. The gas generator according to claim 1, wherein the second forming portion is a resin molded product. The second forming portion is formed with at least a part of the outer peripheral portion having a positioning portion for positioning one end portion of the housing used when fixing the holder to one end portion of the housing. The gas generator according to claim 1 or 2.

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