Gas generator

Abstract

To obtain a gas generator which achieves cost reduction by achieving reduction of the weight and simplification of components, compared to conventional gas generators.SOLUTION: A gas generator 100 has an outer shape of an elongated substantially columnar shape and includes: a housing 10; a holder 20 attached to one opening end of the housing 10; an igniter 50 which is held by the holder 20 and ignites the gas generator 31; a cup member 32; and a filter 41. The cup member 32 is installed within the housing 10 with one end of the filter 41 inserted into the cup member 32, and then a diameter is reduced to the radial inner side at a portion, which corresponds to a part of a peripheral surface of a cylindrical part 32a of the cup member 32, of a peripheral wall 10b of the housing 10 to form an annular groove part 32a1 and an annular groove part 41b and thereby crimp the cup member 32 to the housing 10 and the filter 41.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] 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 particularly to a so-called cylinder-type gas generator having an elongated cylindrical shape. [Background technology]

[0002] A long cylindrical housing in a cylinder-type gas generator is generally configured such that one end is closed by a closing member and the other end is closed by a holder having an ignition portion (see, for example, Patent Document 1 listed below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5455932 Summary of the Invention [Problem to be solved by the invention]

[0004] However, for the gas generators typified by those disclosed in the above patent documents, further cost reductions through weight reduction and simplification of parts are desired.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a gas generator that is lighter in weight than conventional gas generators and has simpler components, thereby reducing costs. [Means for solving the problem]

[0006] (1) A gas generator of the present invention comprises a long cylindrical housing loaded with a gas generating agent that generates gas by combustion, containing a filter inside through which the gas passes, and having a gas outlet formed at a position corresponding to the filter for ejecting the gas; an igniter capable of igniting and burning the gas generating agent; a holder that holds a part of the igniter and is fixed to one axial end of the housing; a blocking member that is fixed to the other axial end of the housing; and a positioning member that comes into contact with the filter within the housing and can be used to determine the position of the filter, wherein the positioning member has a cylindrical portion that is shaped to at least match the shape of the inner wall of the housing, and the cylindrical portion is fixed to a predetermined location on the inner wall of the housing by welding or diameter reduction processing performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas outlet.

[0007] (2) In the gas generator of (1) above, it is preferable that the positioning member is a short, bottomed, cylindrical cup member that covers one end side of the filter, and that the cup member and the filter are deformed together with the housing by reducing the diameter of each side portion of the cup member and the filter together with the housing from the outside, thereby fixing the filter to the housing via the cup member.

[0008] (3) In the gas generator of (1) above, the positioning member may be a tubular member that is shorter than the axial length of the filter and blocks the gas outlet within the housing, and may be subjected to a diameter reduction process from the outside together with the housing at a position closer to the igniter than the region of each side surface of the tubular member and the filter where the gas outlet is formed, and at a position closer to the blocking member than the region of each side surface of the tubular member and the filter where the gas outlet is formed, thereby deforming the tubular member and the filter together with the housing and fixing the filter to the housing via the tubular member.

[0009] (4) In the gas generator of (1) above, the positioning member may be a short, bottomed, cylindrical cup member having a cylindrical portion on the opposite side of the filter and a bottom portion in contact with the filter, and the cup member may be fixed to the housing by bonding the cylindrical portion to the inner wall of the housing by the welding process.

[0010] (5) In the gas generators of (2) to (4) above, it is preferable that the blocking member is disposed and positioned so that one end side contacts the other end side of the filter within the housing, and is a member that is fixed between the housing and the filter by reducing the diameter of the housing at the other end side so as to push the blocking member toward the filter.

[0011] (6) In the gas generator of (1) above, it is preferable that the positioning member is a long, bottomed tubular member having a tubular side portion that closes the gas outlet within the housing and a bottom portion that closes the other end of the filter, and that the bottomed tubular member and the filter are reduced in diameter together with the housing from the outside at positions on the igniter side of the region where the gas outlet is formed, thereby deforming the bottomed tubular member and the filter together with the housing and fixing the filter to the housing via the bottomed tubular member.

[0012] (7) In the gas generator of (6) above, it is preferable that the blocking member is disposed and positioned so that one end side contacts the bottom surface portion of the bottomed tubular member within the housing, and is a member that is fixed between the housing and the filter by reducing the diameter of the housing at the other end side so as to push the blocking member toward the filter side.

[0013] (8) The cup member of (2) above, the tubular member of (3) above, or the bottomed cylindrical member of (6) above is preferably made of a resin member or a composite reinforcing member containing resin.

[0014] (9) It is preferable that the filter of (3) or (6) above is formed in a cylindrical shape having a space in the center, and that the gas generating agent is also loaded in the space. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a gas generator that is lighter in weight and has simpler components than conventional gas generators, thereby reducing costs. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram (partially omitted) showing the internal structure of a gas generator according to a first embodiment of the present invention, shown partially in cross section. [Figure 2] FIG. 2 is an enlarged view of a portion of the gas generator of FIG. 1. [Figure 3] 10 is a schematic diagram (partially omitted) showing the internal structure of a gas generator according to a second embodiment of the present invention, shown partially in cross section. FIG. [Figure 4] FIG. 4 is an enlarged view of a portion of the gas generator of FIG. 3. [Figure 5] FIG. 10 is a schematic diagram (partially omitted) showing the internal structure of a gas generator according to a third embodiment of the present invention, shown partially in cross section. [Figure 6] FIG. 6 is an enlarged view of a portion of the gas generator of FIG. 5. [Figure 7] 10 is a partially enlarged schematic view (with some parts omitted) showing the internal structure of a gas generator according to a fourth embodiment of the present invention, shown partially in cross section. FIG. [Figure 8] 10 is a partially enlarged schematic view (with some parts omitted) showing the internal structure of a gas generator according to a fifth embodiment of the present invention, shown partially in cross section. [Figure 9] 10 is a partially enlarged schematic view (with some parts omitted) showing the internal structure of a gas generator according to a sixth embodiment of the present invention, shown partially in cross section. FIG. [Figure 10] 13 is a partially enlarged schematic view (with some parts omitted) showing the internal structure of a gas generator according to a seventh embodiment of the present invention, shown partially in cross section. [Figure 11] FIG. 13 is a schematic diagram (partially omitted) showing the internal structure of a gas generator according to an eighth embodiment of the present invention, shown partially in cross section. [Figure 12] FIG. 12 is an enlarged view of a portion of the gas generator of FIG. 11. [Figure 13] FIG. 13 is a schematic diagram (partially omitted) showing the internal structure of a gas generator according to a ninth embodiment of the present invention, shown partially in cross section. [Figure 14] FIG. 14 is an enlarged view of a portion of the gas generator of FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0017] First Embodiment Hereinafter, with reference to Figs. 1 and 2, the internal structure of a cylinder-type gas generator according to an embodiment of the present invention will be described.

[0018] (Configuration of gas generator 100) Gas generator 100 has a long, approximately cylindrical outer shape and includes housing 10, holder 20 attached to one open end of housing 10, and closing member 12 attached to the other end of housing 10 so as to close the other open end of housing 10.

[0019] Housing 10 has peripheral walls 10a, 10b, and 10e and is made of a long, cylindrical member having openings at both axial ends. Closing member 12 is made of a disk-shaped member having a predetermined thickness, and has an annular groove 13 on its peripheral surface for fixation by crimping (an example of a diameter-reducing processing method) described below. This annular groove 13 for fixation by crimping is formed on the peripheral surface of closing member 12 so as to extend in the circumferential direction. In addition, gas outlets 11 are provided in the peripheral wall of housing 10 near the end on the side where closing member 12 is attached. These gas outlets 11 are holes for ejecting gas generated inside gas generator 100 to the outside, and a plurality of gas outlets 11 are provided along the circumferential and axial directions of housing 10.

[0020] 1 and 2, with a portion of the closing member 12 inserted into one open end of the housing 10, the peripheral wall 10a of the housing 10 is narrowed (crimped) radially inward to form the annular groove 13, thereby crimping and fixing the closing member 12 to the housing 10.

[0021] Holder 20 is made of a metal such as stainless steel, iron steel, aluminum alloy, or stainless alloy, and has a tapered fitting portion 23 into which igniter 50 fits, an annular groove portion 22 for crimping and fixed formed so as to extend circumferentially on the outer circumferential surface, and a fitting portion 21, on the side opposite to the holding position of igniter 50, into which a female connector (not shown) for supplying electricity to igniter 50 can be fitted. Note that holder 20 is crimped and fixed to housing 10 by reducing (crimping) the diameter of peripheral wall 10e of housing 10 in a portion corresponding to annular groove portion 22 provided on the outer circumferential surface of holder 20 inward in the radial direction and engaging with said annular groove portion 22.

[0022] As described above, a female connector is formed in fitting portion 21 of holder 20. This female connector is a portion to which a male connector of a harness that transmits a signal from collision detection means that is provided separately from gas generator 100 is connected. A retainer 60 is attached to the female connector. This retainer 60 is attached to prevent malfunction of cylindrical gas generator 100 due to electrostatic discharge or the like when gas generator 100 is transported, and at the stage of assembly into an airbag device, the male connector of the harness is inserted into the female connector, thereby releasing contact with terminal pin 52.

[0023] 1, an igniter 50 is disposed at one axial end of the housing 10 (i.e., the portion closer to the holder 20) as an ignition means for the gas generating agent 31. The igniter 50 and the holder 20 that fixes the igniter 50 function as ignition means that generate a flame for burning the granular gas generating agent 31, which will be described later.

[0024] As shown in Fig. 1, igniter 50 is inserted into fitting portion 23 of holder 20 and held together with a substantially cylindrical member 53, which will be described later. More specifically, igniter 50 includes a base frame through which a pair of terminal pins 52 are inserted and which holds the pair, and a squib cup 51 (cup-shaped member) attached to the base frame. A resistor (bridge wire) is attached so as to connect the tips of terminal pins 52 inserted into squib cup 51, and squib cup 51 is filled with an ignition charge so as to surround or 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 tricinate, or the like is generally used as the ignition charge. In addition to the ignition charge, a transfer charge may also be filled into squib cup 51. Examples of transfer charges that can be placed together with the ignition charge include a composition consisting of a metal / oxidizer, such as boron / potassium nitrate, a composition consisting of titanium hydride / potassium perchlorate, or a composition consisting of boron / 5-aminotetrazole / potassium nitrate / molybdenum trioxide.

[0025] When a collision is detected, a predetermined amount of current flows through the resistor via terminal pin 52. This current flow through the resistor generates Joule heat, which causes the ignition charge to begin burning. The high-temperature flame generated by the combustion ruptures squib cup 51, which contains the ignition charge. If nichrome wire is used for the resistor, the time from when the current flows through the resistor to when igniter 50 is activated is less than 2 milliseconds.

[0026] Squib cup 51 is generally made of metal or resin. A substantially cylindrical member 53 covers the peripheral wall of squib cup 51 except for the vicinity of the tip, and is fixed together with igniter 50 by crimping to holder 20 with crimping portion 24. Here, substantially cylindrical member 53 is a directional member that directs the direction of the flame generated in igniter 50 upon activation toward cup member 32 (positioning member).

[0027] As shown in FIG. 1, in the internal space of the housing 10, a space 10A in which a gas generating agent 31 and the like are sealed, and a filter 41 are provided in parallel in the axial direction of the housing 10.

[0028] The gas generating agent 31 is a composition that is ignited by a flame generated by ignition by the igniter 50 and burns to generate gas. The gas generating agent 31 is generally formed as a molded body containing a fuel, an oxidizer, and an additive. Examples of fuels that can be used include triazole derivatives, tetrazole derivatives, guanidine derivatives, azodicarbonamide derivatives, hydrazine derivatives, and combinations thereof. Specific examples of suitable fuels include nitroguanidine, guanidine nitrate, cyanoguanidine, and 5-aminotetrazole. Examples of suitable oxidizers include basic metal nitrates such as basic copper nitrate and basic copper carbonate, perchlorates such as ammonium perchlorate and potassium perchlorate, and nitrates containing cations selected from alkali metals, alkaline earth metals, transition metals, and ammonia. Suitable examples of suitable nitrates include sodium nitrate and potassium nitrate. Examples of suitable additives include binders, slag-forming agents, and combustion modifiers. Suitable binders include organic binders such as cellulose derivatives (e.g., hydroxypropylene methyl cellulose), metal salts of carboxymethyl cellulose, and stearates, as well as inorganic binders (e.g., synthetic hydroxytalcite and acid clay). Suitable slag-forming agents include silicon nitride, silica, and acid clay. Suitable combustion-adjusting agents include metal oxides, ferrosilicon, activated carbon, and graphite.

[0029] 1, the coil spring 35 is formed by being wound in a spiral shape so that its overall appearance resembles a truncated cone. One end of the coil spring 35 abuts against the squib cup 51, and the other spirally formed end abuts against the gas generating agent 31, thereby applying an elastic force to the gas generating agent 31. Due to this biasing force, the gas generating agent 31 is fixed in the housing 10 by being sandwiched between the coil spring 35 and the cup member 32. Furthermore, the coil spring 35 has an overall truncated cone shape whose diameter increases from the igniter 50 side to the gas generating agent 31 side, which makes it easier to direct the direction of the flame emitted from the igniter 50 toward the gas generating agent 31.

[0030] The cup member 32 (positioning member) is a short, bottomed, cylindrical member that covers one end of the filter 41. It includes a cylindrical portion 32a having an annular groove 32a1 and a bottom portion 32b that closes one end of the cylindrical portion 32a. The cup member 32 is fixed to the inner wall of the housing 10 by a diameter-reducing process (described later) performed from the outside of the housing 10 so that the filter 41 can be positioned at a predetermined position (for example, a position facing the gas outlet 11 as shown in FIGS. 1 and 2). The cylindrical portion 32a is short enough not to close the gas outlet 11. The bottom portion 32b is designed to melt or break due to the gas generated during operation. The cup member 32 is made of a resin material or a composite reinforced material containing resin. Examples of the resin material or composite reinforced material containing resin include glass fiber-reinforced PA6 (polyamide 6) and POM (polyacetal, polyoxymethylene). As a modified example, the cup member 32 may be made of a metal such as stainless steel or steel, or an alloy such as an aluminum alloy or stainless alloy.

[0031] 1 and 2, after the cup member 32 is installed in the housing 10 with one end of the filter 41 fitted into it, the peripheral wall 10b of the housing 10 is narrowed radially inward (crimped) at a portion corresponding to a part of the circumferential surface of the cylindrical portion 32a of the cup member 32 to form the annular groove 32a1 and the annular groove 41b (described later), thereby crimping and fixing the cup member 32 to the housing 10 and the filter 41. This prevents generated gas from bypassing between the inner wall of the housing 10 and the outer periphery of the filter 41 and leaking into the gas outlet 11, while also ensuring sealing. That is, the cup member 32 allows gas generated on the igniter 50 side of the housing 10 to flow into the filter 41 side through a portion of the bottom portion 32b that is split by melting or breaking (a portion corresponding to one end of the hollow portion 41a). The crimping and fixing position may be any position that corresponds to the circumferential surface of the cylindrical portion 32a of the cup member 32.

[0032] The filter 41 is a cylindrical member having a central hollow portion 41a (e.g., approximately cylindrical or rectangular). As described above, the filter 41 is installed in the housing 10 together with the cup member 32, and then the annular groove 41b is formed by the diameter reduction process. The use of the cylindrical filter 41 reduces the flow resistance of the working gas flowing during operation, enabling efficient gas flow. The filter 41 may be made of wire material made of metal such as stainless steel or steel, or a mesh material wound or compressed by pressing. Specifically, a knitted wire mesh, a plain weave wire mesh, or an assembly of crimped metal wire materials may be used. The filter 41 functions as a cooling means for cooling the gas generated in the housing 10 by removing the high-temperature heat of the gas as it passes through the filter 41, and also functions as a removal means for removing slag and other contaminants contained in the gas. Here, as a modification of the filter 41, a filter having a labyrinth flow path formed by combining roughly cylindrical or cone-shaped metal parts may be used. This allows the path of the working gas to be changed in various directions, thereby enabling cooling of the gas and removal of slag.

[0033] Furthermore, in the above-described embodiment of the present invention, a filter made of so-called knitted wire mesh is used as an example, but it is also possible to use a filter made by winding punched metal or expanded metal instead. Here, punched metal refers to a metal plate in which only openings are provided (i.e., no protrusions are provided around the edges of the openings), and expanded metal refers to a metal plate in which openings are provided in the plate metal member by, for example, making staggered cuts and then expanding the cuts to form a mesh-like structure. Even when such punched metal or expanded metal is used instead of the above-described knitted wire mesh, the same effects as those described in the above-described embodiment of the present invention can be obtained.

[0034] Furthermore, in the above-described perforated metal and expanded metal, the filter is formed as a laminate by winding a single metal plate-like member, but the configuration of the filter is not limited to this. That is, the filter may be formed as a laminate by combining different metal plate-like members each having different layers, or the filter may be formed as a laminate by combining a plurality of layers in which some layers are formed as a single metal plate-like member and the remaining layers are formed as a different single metal plate-like member.

[0035] Next, an operation during activation of gas generator 100 described above will be described. When a vehicle equipped with an airbag device incorporating gas generator 100 in the present embodiment collides, the collision is detected by collision detection means separately provided in the vehicle, and igniter 50 is activated based on this detection. When igniter 50 is activated, the pressure inside igniter 50 increases due to combustion of the ignition charge, causing the tip of squib cup 51 of igniter 50 to rupture, and a flame flows from the tip of squib cup 51 of igniter 50 to the cup member 32 side inside housing 10.

[0036] The flame flowing in in this manner ignites and burns the gas generating agent 31 in the housing 10, generating a large amount of gas. This combustion of the gas generating agent 31 increases the pressure in the space 10A in the housing 10, and the generated gas melts or breaks open a portion of the bottom surface portion 32b of the cup member 32 corresponding to the hollow portion 41a, and flows into the hollow portion 41a. The generated gas then passes through the filter 41 and is ejected from the gas outlet 11 to the outside of the gas generator 100, but because it passes through the filter 41, the generated gas is cooled to a predetermined temperature. The gas ejected from the gas outlet 11 is then guided into the interior of the airbag to inflate and deploy the airbag.

[0037] (Main features of the gas generator 100) According to the present embodiment, it is possible to provide gas generator 100 in which the number of parts can be reduced compared to conventional cases, thereby reducing weight, and in which costs can be reduced by simplifying the parts. In particular, when cup member 32 is made of resin, it is possible to achieve further weight reduction and cost reduction.

[0038] Furthermore, in this embodiment, the cup member 32, the filter 41, and the housing 10 are crimped together at the positions of the annular groove portion 32a1, the annular groove portion 41b, and the peripheral wall 10b. This not only enables the cup member 32 to be crimped and fixed to the housing 10 and the filter 41, but also prevents the generated gas from bypassing between the inner wall of the housing 10 and the outer periphery of the filter 41 and leaking out to the gas outlet 11, and ensures the sealing properties of the housing 10.

[0039] Furthermore, by using the bottom surface portion 32b of the cup member 32 as a partition plate, the breaking pressure during operation can be reduced, and therefore the internal pressure of the housing 10 (space 10A) can be reduced during combustion.

[0040] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Figures 3 and 4. In this embodiment, parts having the same reference numerals as those in the first embodiment down to the last two digits are the same as those in the first embodiment, and therefore their description may be omitted. Furthermore, parts in this embodiment that are not particularly described are also the same as those in the first embodiment, and therefore their description and illustration may be omitted.

[0041] 3 and 4, gas generator 200 according to the present embodiment differs from the first embodiment in that, instead of cup member 32 in the first embodiment, a long, bottomed tubular member 133 (positioning member) is used, which has a cylindrical side surface portion 133a that closes gas outlet 111 within housing 110, and a bottom surface portion 133b that closes the other end side (closing member 112 side) of filter 141. Bottomed tubular member 133 is fixed to the inner wall of housing 110 by a diameter-reducing process described below that is performed from the outside of housing 110, so that filter 141 can be positioned at a predetermined position (for example, a position facing gas outlet 111 as in FIGS. 3 and 4). Bottomed tubular member 133 is made of a resin member or a composite reinforced member that includes a resin. Examples of this resin member or composite reinforcing member containing resin include PA6 (polyamide 6) containing 30% glass fiber, POM (polyacetal, polyoxymethylene), PA6, etc. As a modified example, the bottomed tubular member 133 may be made of a metal such as stainless steel or steel, or an alloy such as an aluminum alloy or stainless steel alloy.

[0042] 3 and 4, gas generator 200 differs from the first embodiment in that, after filter 141 is fitted into bottomed tubular member 133 and installed inside housing 110, peripheral wall 110b of housing 110 at a portion corresponding to part of the peripheral surface of side surface portion 133a of bottomed tubular member 133 is reduced in diameter inward in the radial direction (crimped) to form annular groove portion 133a1 and annular groove portion 141b, thereby crimping and fixing bottomed tubular member 133 to housing 110 and filter 141. Note that the position of the crimping may be any position on the igniter 150 side relative to gas outlet 111.

[0043] The gas generator 200 also differs from the first embodiment in that the gas generating agent 131 is loaded also in the hollow portion 141a.

[0044] Next, an operation during activation of gas generator 200 described above will be described. When a vehicle equipped with an airbag device incorporating gas generator 200 in the present embodiment collides, the collision is detected by collision detection means separately provided in the vehicle, and igniter 150 is activated based on this detection. When igniter 150 is activated, the pressure inside igniter 150 increases due to combustion of the ignition charge, causing the tip of squib cup 151 of igniter 150 to rupture, and flames flow from the tip of squib cup 151 of igniter 150 to the side of filter 141 inside housing 110.

[0045] The flame that has flowed in in this manner ignites and burns gas generating agent 131 in housing 110, generating a large amount of gas. This combustion of gas generating agent 131 increases the pressure in space 110A in housing 110, and the generated gas flows into hollow portion 141a of filter 141. Next, the generated gas passes through filter 141 and causes a portion of bottomed tubular member 133 corresponding to gas outlet 111 to rupture due to the gas pressure. Thereafter, the gas is ejected from gas outlet 111 to the outside of gas generator 200, but because it passes through filter 141, the generated gas is cooled to a predetermined temperature. Then, the gas ejected from gas outlet 111 is guided into the interior of the airbag to inflate and deploy the airbag.

[0046] According to the present embodiment, it is possible to provide gas generator 200 in which the number of parts can be reduced compared to conventional cases, thereby reducing weight, and costs can be reduced by simplifying the parts. In particular, when bottomed tubular member 133 is made of resin, it is possible to achieve further weight reduction and cost reduction.

[0047] Furthermore, in this embodiment, the bottomed tubular member 133, the filter 141, and the housing 110 are crimped together at the positions of the annular groove portion 133a1, the annular groove portion 141b, and the peripheral wall 110b. This not only allows the bottomed tubular member 133 to be crimped and fixed to the housing 110 and the filter 141, but also prevents the generated gas from bypassing between the inner wall of the housing 110 and the outer periphery of the filter 141 and leaking out to the gas outlet 111, and ensures the sealing properties of the housing 110.

[0048] Furthermore, according to this embodiment, the gas generating agent 131 is also loaded inside the hollow portion 141a, so that if the housing has the same diameter, the overall axial length can be made shorter than that of the first embodiment.

[0049] Third Embodiment Next, a third embodiment of the present invention will be described with reference to Figures 5 and 6. In this embodiment, parts having the same reference numerals as those in the first embodiment down to the last two digits are the same as those in the first embodiment, and therefore their description may be omitted. Furthermore, parts not particularly described in this embodiment are the same as those in the first embodiment, and therefore their description and illustration may be omitted.

[0050] As shown in FIGS. 5 and 6, gas generator 300 according to this embodiment differs from the second embodiment in that a tubular member 234 (positioning member) that closes gas outlet 211 within housing 210 is used instead of bottomed cylindrical member 133 in the second embodiment. Tubular member 234 is fixed to the inner wall of housing 210 by a diameter-reducing process (described later) performed from the outside of housing 210 so that filter 241 can be positioned at a predetermined position (for example, a position facing gas outlet 211 as in FIGS. 5 and 6). Tubular member 234 is made of a resin member or a composite reinforcing member containing resin. Examples of this resin member or composite reinforcing member containing resin include PA6 (polyamide 6), POM (polyacetal, polyoxymethylene), PA6, and the like, containing 30% glass fiber. As a modified example, tubular member 234 may be made of a metal such as stainless steel or steel, or an alloy such as an aluminum alloy or stainless steel alloy.

[0051] 5 and 6, gas generator 200 is installed in housing 210 with filter 241 fitted into tubular member 234, and then circumferential walls 210b, 210c of housing 210 at portions corresponding to two locations on the circumferential surface of tubular member 234 are reduced inward in the radial direction (crimped) to form annular grooves 234a1 and 241b, and annular grooves 234a2 and 241c, thereby crimping and fixing tubular member 234 to housing 210 and filter 241. Note that the positions of the above-mentioned two crimping locations may be any positions other than the region where gas outlet 211 is formed, that is, positions closer to igniter 150 than gas outlet 211 formed closest to igniter 150, and positions closer to blocking member 212 than gas outlet 211 formed closest to blocking member 212.

[0052] According to this embodiment, it is possible to achieve the same effects as those of the second embodiment.

[0053] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described with reference to Fig. 7. In this embodiment, parts having the same reference numerals as those in the first embodiment down to the last two digits are the same as those in the first embodiment, and therefore their description may be omitted. Furthermore, parts not particularly described in this embodiment are the same as those in the first embodiment, and therefore their description and illustration may be omitted.

[0054] As shown in FIG. 7, the gas generator according to this embodiment differs from the first embodiment mainly in that a disk-shaped closing member 312 is used instead of closing member 12 in the first embodiment.

[0055] Closing member 312 is disposed and positioned within housing 310 so that one end (filter 341) contacts the other end of filter 341. The method for fixing closing member 312 to housing 310 is as follows: Housing 310 is subjected to a diameter reduction process (here, crimping process) on the other end side of closing member 312 so that closing member 312 is pressed toward filter 341, thereby forming annular groove 310a. In this way, closing member 312 is fixed between housing 310 and filter 341 in just one process.

[0056] According to this embodiment, it is possible to achieve the same effects as in the first embodiment. Furthermore, since the blocking member 312 is fixed between the housing 310 and the filter 341 by being pressed against the other end of the filter 341, it is possible to prevent the blocking member 312 from moving during installation. As a result, the inner side of the crimped portion of the housing 310 is more likely to bite into the blocking member 312, and the strength of the crimped fixation can be improved compared to the first embodiment.

[0057] Furthermore, according to the present embodiment, the shape of closing member 312 can be simplified, thereby reducing costs for cutting and the like. Furthermore, when the gas generator of the present embodiment has the same diameter as the housing of the gas generator of the first embodiment, the thickness of closing member 312 can be made thinner, thereby enabling the axial length of the entire gas generator to be shortened and the weight to be reduced compared to the first embodiment. The reason why the thickness of closing member 312 can be made thinner compared to closing member 12 of the first embodiment is as follows. In the first embodiment, closing member 12 is provided with annular groove portion 13 and is crimped and fixed to housing 10 from the outside, thereby fixing the position of closing member 12 relative to housing 10. On the other hand, in the present embodiment, filter 341 is fixed by cup member 332 (positioning member), and therefore the position of closing member 312 is necessarily determined. Therefore, it is possible to crimp and fix closing member 312 only to the axial outside of housing 310, allowing closing member 312 to be made thinner compared to closing member 12 of the first embodiment.

[0058] Fifth Embodiment Next, a fifth embodiment of the present invention will be described with reference to Fig. 8. In this embodiment, parts having the same reference numerals as those in the first embodiment down to the last two digits are the same as those in the first embodiment, and therefore their description may be omitted. Furthermore, parts not particularly described in this embodiment are the same as those in the first embodiment, and therefore their description and illustration may be omitted.

[0059] As shown in FIG. 8, the gas generator according to this embodiment differs from the first embodiment mainly in that a disc-shaped closing member 412 having a stepped shape is used instead of closing member 12 in the first embodiment.

[0060] Closing member 412 has first-step portion 412a and second-step portion 412b provided so as to form a staircase shape together with first-step portion 412a, and is disposed and positioned so that one end (filter 441) side contacts the other end of filter 441 within housing 410. The method for fixing closing member 412 to housing 410 is as follows: Housing 410 is subjected to diameter reduction processing (here, crimping processing) on ​​the other end side of first-step portion 412a of closing member 412, so that closing member 412 is pressed toward filter 441, and annular groove 410a is formed. As a result, closing member 412 is fixed between housing 410 and filter 441 in just one process.

[0061] According to this embodiment, it is possible to achieve the same effects as those of the fourth embodiment. Furthermore, since the blocking member 412 is a disc-shaped member having a stepped shape, it is possible to make it thicker in the axial direction of the housing 410 than the blocking member 312 of the fourth embodiment, and it is possible to make the blocking member 412 stronger than the blocking member 312.

[0062] Sixth Embodiment Next, a sixth embodiment of the present invention will be described with reference to Fig. 9. In this embodiment, parts having the same reference numerals as those in the second embodiment down to the last two digits are the same as those in the second embodiment, and therefore their description may be omitted. Furthermore, parts in this embodiment that are not particularly described are also the same as those in the second embodiment, and therefore their description and illustration may be omitted.

[0063] As shown in FIG. 9, the gas generator according to this embodiment differs from the second embodiment mainly in that a disk-shaped closing member 512 is used instead of closing member 112 in the second embodiment.

[0064] Closing member 512 is disposed and positioned within housing 510 so that one end (filter 541) contacts the other end of filter 541. Closing member 512 is fixed to housing 510 as follows: Housing 510 is subjected to a diameter reduction process (here, crimping process) on the other end side of closing member 512 so that closing member 512 is pressed toward filter 541, thereby forming annular groove 510a. As a result, closing member 512 is fixed between housing 510 and filter 541 in only one process.

[0065] According to this embodiment, it is possible to achieve the same effects as those of the second embodiment. Furthermore, since closing member 512 is fixed between housing 510 and filter 541 by being pressed against bottom surface portion 533b of bottomed tubular member 533, it is possible to prevent closing member 512 from moving during installation. As a result, the inner side of the crimped portion of housing 510 is more likely to bite into closing member 512, and the strength of the crimped fixation can be improved compared to the second embodiment.

[0066] Furthermore, according to the present embodiment, the shape of closing member 512 can be simplified, thereby reducing the costs for cutting work, etc. Furthermore, when the gas generator of the present embodiment has the same diameter as the housing of the gas generator of the second embodiment, it is possible to reduce the thickness of closing member 512, and therefore the axial length of the entire gas generator can be shortened and the weight can be reduced compared to the second embodiment.

[0067] Seventh Embodiment Next, a seventh embodiment of the present invention will be described with reference to Fig. 10. In this embodiment, parts having the same reference numerals as those in the third embodiment down to the last two digits are the same as those in the third embodiment, and therefore their description may be omitted. Furthermore, parts in this embodiment that are not particularly described are also the same as those in the third embodiment, and therefore their description and illustration may be omitted.

[0068] As shown in FIG. 10, the gas generator according to this embodiment differs from the third embodiment mainly in that a disk-shaped closing member 612 is used instead of closing member 212 in the third embodiment.

[0069] Closing member 612 is disposed and positioned within housing 610 so that one end (filter 641) contacts the other end of filter 641. The method for fixing closing member 612 to housing 610 is as follows: Housing 610 is subjected to a diameter reduction process (here, crimping process) on the other end side of closing member 612 so that closing member 612 is pressed toward filter 641, thereby forming annular groove 610a. In this way, closing member 612 is fixed between housing 610 and filter 641 in just one process.

[0070] According to this embodiment, it is possible to achieve the same effects as in the third embodiment. Furthermore, since blocking member 612 is fixed between housing 610 and filter 641 so as to be pressed against the other end of filter 641, it is possible to prevent blocking member 612 from moving during installation. As a result, the inner side of the crimped portion of housing 610 is more likely to bite into blocking member 612, and the strength of the crimped fixation can be improved compared to the third embodiment.

[0071] Furthermore, according to the present embodiment, the shape of closing member 612 can be simplified, thereby reducing the costs for cutting work, etc. Furthermore, when the gas generator of the present embodiment has the same diameter as the housing of the gas generator of the third embodiment, it is possible to reduce the thickness of closing member 612, and therefore the axial length of the entire gas generator can be shortened and the weight can be reduced compared to the third embodiment.

[0072] Eighth Embodiment Next, an eighth embodiment of the present invention will be described with reference to Figures 11 and 12. In this embodiment, parts having the same reference numerals as those in the first embodiment down to the last two digits are the same as those in the first embodiment, and therefore their description may be omitted. Furthermore, parts in this embodiment that are not particularly described are also the same as those in the first embodiment, and therefore their description and illustration may be omitted.

[0073] As shown in Figures 11 and 12, the gas generator according to this embodiment differs from the first embodiment mainly in that (1) a disk-shaped closure member 712 is used instead of the closure member 12 in the first embodiment, (2) a cup member 732 is used instead of the cup member 32 in the first embodiment, and (3) an AI agent 740 is provided in approximately the center of the bottom surface portion 732b of the cup member 732 on the gas generating agent 731 side.

[0074] Closing member 712 is disposed and positioned within housing 710 so that one end (filter 741) contacts the other end of filter 741. The method for fixing closing member 712 to housing 710 is as follows: Housing 710 is subjected to a diameter reduction process (here, crimping process) on the other end side of closing member 712 so that closing member 712 is pressed toward filter 741, thereby forming annular groove 710a. In this way, closing member 712 is fixed between housing 710 and filter 741 in just one process.

[0075] The cup member 732 is made of a material that can be used for welding and bonding, such as a metal or alloy, and includes a cylindrical portion 732a and a bottom portion 732b provided on the other end of the cylindrical portion 732a. The cylindrical portion 732a is fixed to the housing 710 by external welding at the position of the peripheral wall 710d (weld location) of the housing 710. This enables the positioning of the filter 741 and, by extension, the positioning of the blocking member 712 before the diameter reduction process. The cup member 732 is also a bottomed, cylindrical bypass prevention member that divides the housing 10 in the axial direction, and can prevent the generated gas from bypassing between the inner wall of the housing 10 and the outer periphery of the filter 41 and leaking into the gas outlet 11.

[0076] The AI ​​agent 740 has an auto-ignition (AI) function that automatically ignites without the operation of the igniter 750. Explaining in more detail, the AI ​​agent 740 automatically ignites at a lower temperature than the gas generating agent 731, and therefore, in the unlikely event of a fire or the like occurring in a vehicle or the like equipped with an airbag device or the like incorporating the gas generator 800, it is possible to prevent the gas generator 800 from malfunctioning due to external heating.

[0077] According to this embodiment, it is possible to achieve the same effects as in the first embodiment. Furthermore, since blocking member 712 is fixed between housing 710 and filter 741 by being pressed against the other end of filter 741, it is possible to prevent movement of blocking member 712 during installation. As a result, the inner side of the crimped portion of housing 710 is more likely to bite into blocking member 712, and the strength of the crimped fixation can be improved compared to the first embodiment.

[0078] Furthermore, according to the present embodiment, the shape of closing member 712 can be simplified, thereby reducing the costs for cutting work, etc. Furthermore, when the gas generator of the present embodiment has the same diameter as the housing of the gas generator of the first embodiment, it is possible to reduce the thickness of closing member 712, and therefore the axial length of the entire gas generator can be shortened and the weight can be reduced, compared to the first embodiment.

[0079] Ninth Embodiment Next, a ninth embodiment of the present invention will be described with reference to Figures 13 and 14. In this embodiment, parts having the same reference numerals as those in the eighth embodiment down to the last two digits are the same as those in the eighth embodiment, and therefore their description may be omitted. In addition, parts in this embodiment that are not particularly described are also the same as those in the eighth embodiment, and therefore their description and illustration may be omitted.

[0080] As shown in Figures 13 and 14, the gas generator according to this embodiment differs from the eighth embodiment in that a disc-shaped closing member 812 having a stepped shape is used instead of closing member 712 in the eighth embodiment.

[0081] Closing member 812 has a first step portion 812a and a second step portion 812b that is provided so as to form a staircase shape together with first step portion 812a, and is disposed and positioned so that one end (filter 841) side contacts the other end of filter 841 within housing 810. The method for fixing closing member 812 to housing 810 is as follows: Housing 810 is subjected to a diameter reduction process (here, crimping process) on the other end side of first step portion 812a of closing member 812, so that closing member 812 is pressed toward filter 841, and annular groove 810a is formed. As a result, closing member 812 is fixed between housing 810 and filter 841 in just one process.

[0082] According to this embodiment, it is possible to achieve the same effects as those of the eighth embodiment. In addition, since the blocking member 812 is a disc-shaped member having a stepped shape, it is possible to make it thicker in the axial direction of the housing 810 than the blocking member 712 of the eighth embodiment, and it is possible to make the blocking member 812 stronger than the blocking member 712.

[0083] Although the embodiments of the present invention have been described above with reference to the drawings, it should be understood that the specific configurations are not limited to these embodiments. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims.

[0084] For example, in the second and third embodiments, the gas generating agent does not have to be filled in the hollow portion of the filter.

[0085] Furthermore, in the first to third embodiments, the method of reducing the diameter of the housing is explained by taking caulking as an example, but any processing method that can reduce the diameter of the housing may be used.

[0086] Furthermore, the present invention may also be a gas generator formed by appropriately combining the respective configurations shown in the first to ninth embodiments. [Explanation of symbols]

[0087] 10, 110, 210, 310, 410, 510, 610, 710, 810 Housing 10A, 110A, 210A, 710A, 810A space 10a, 10b, 10e, 110a, 110b, 110e, 210b, 210c, 310a, 310b, 410a, 410b, 510a, 510b, 610a, 610b, 610c, 710a, 710d, 710e, 810a, 810e Peripheral wall 11, 111, 211, 311, 411, 511, 611, 711, 811 Gas outlet 12, 112, 212, 312, 412, 512, 612, 712, 812 Closure members 13, 22, 32a1, 41b, 113, 133a1, 141b, 213, 122, 222, 234a1, 234a2, 241b, 241c, 332a1, 341b, 432a1, 441b, 533a1, 541b, 634a1, 634a2, 641b, 641c, 722, 822 Annular groove 20, 120, 220, 720, 820 holder 21, 23, 121, 123, 221, 223, 721, 723, 821, 823 Mating part 24, 124, 224, 724, 824 Crimping part 31, 131, 231, 331, 431, 531, 631, 731, 831 Gas Generators 32, 132, 232, 332, 432, 732, 832 Cup member 32a, 332a, 432a, 732a, 832a Cylindrical part 32b, 133b, 332b, 432b, 533b, 732b, 832b Bottom part 35, 135, 235, 735, 835 coil spring 41, 141, 241, 341, 441, 541, 641, 741, 841 filters 41a, 141a, 241a, 341a, 441a, 541a, 641a, 741a, 841a Hollow part 50, 150, 250, 750, 850 igniter 51, 151, 251, 751, 851 Squib Cup 52, 152, 252, 752, 852 terminal pins 53, 153, 253, 753, 853 Cylindrical members 60, 160, 260, 360, 460 retainer 100, 200, 300, 700, 800 Gas Generator 133, 533 Bottomed cylindrical member 133a, 533a side part 234, 634 Tubular members 740 AI Agent

Claims

1. a long cylindrical housing loaded with a gas generating agent that generates gas by burning, containing a filter therein through which the gas passes, and having a gas outlet formed at a position corresponding to the filter for ejecting the gas; an igniter capable of igniting and burning the gas generating agent; a holder that holds a portion of the igniter and is fixed to one axial end of the housing; a blocking member fixed to the other axial end of the housing; a positioning member adapted to contact and position the filter within the housing; Equipped with the positioning member has at least a cylindrical portion whose shape conforms to the shape of the inner wall of the housing, a filter that is in contact with the positioning member and that can be positioned at a position corresponding to the gas outlet, wherein the cylindrical portion is fixed to a predetermined location on an inner wall of the housing by being deformed together with the housing through diameter reduction processing performed from the outside of the housing.

2. a long cylindrical housing loaded with a gas generating agent that generates gas by burning, containing a cylindrical filter therein through which the gas passes, and having a gas outlet formed at a position corresponding to the filter for ejecting the gas; an igniter capable of igniting and burning the gas generating agent; a holder that holds a portion of the igniter and is fixed to one axial end of the housing; a blocking member fixed to the other axial end of the housing; a positioning member provided inside the housing, in contact with an axial end of the filter on the igniter side, and usable to determine the position of the filter; Equipped with the positioning member has at least a cylindrical portion whose shape conforms to the shape of the inner wall of the housing, the cylindrical portion is fixed to a predetermined location on the inner wall of the housing by welding performed from the outside of the housing so that the filter in contact with the positioning member can be positioned at a position corresponding to the gas outlet, The blocking member is a plate-shaped member or a member having a convex cross section, which is formed so as to close the other end of the housing in the axial direction and has a width in a direction perpendicular to the axial direction of the housing that is equal to or smaller than the inner diameter of the housing, The blocking member is disposed and positioned within the housing so that one end thereof contacts the other end of the filter, and is fixed between the housing and the filter by reducing the diameter of the housing at the other end thereof so as to push the blocking member toward the filter. A gas generator characterized by:

3. the positioning member is a short, bottomed, cylindrical cup member having a cylindrical portion on the opposite side to the filter and a bottom portion in contact with the filter, 3. The gas generator according to claim 2, wherein the cup member is fixed to the housing by bonding the cylindrical portion to the inner wall of the housing by the welding process.

Images