Gas generator

Abstract

[Problem] To obtain a gas generator in which cost is reduced by lessening weight and simplifying components to a greter extent than in the prior art. [Solution] This gas generator 100 includes: a housing 10 having an elongated and substantially columnar outer shape; a holder 20 attached to one open end of the housing 10; an igniter 50 held by the holder 20 and igniting a gas generation agent 31; a sealing member 12 attached to the other end of the housing 10 so as to seal the other open end of the housing 10; and a filter 41. The sealing member 12: has an annular groove 13 formed by swaging and thereby reducing the diameter of the circumferential surface of a bottomed cylindrical member having a prescribed thickness; and is formed in a substantially jar-shaped configuration that has an interior space 12a.

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 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; and a closing member that is fixed to the other axial end of the housing, wherein the closing member is fixed to the housing by deforming the side surface of a bottomed tubular member that is inserted partway into the housing from the other end of the housing and reducing the diameter of the side surface of the tubular member together with the housing from the outside at at least one location. The closing member serves to make the internal space of the bottomed tubular member after deformation into a space having a shape that follows the shape of the bottomed tubular member after deformation and a hollow space for reducing internal pressure when gas is generated. Here, "reducing the diameter at one location" means, for example, reducing the diameter annularly around the entire circumference of the side surface of the housing at one location on the side surface of the housing.

[0008] ( 2 ) above (1 )of In the gas generator, it is preferable that the bottomed tubular member is fixed to the housing by reducing the diameter of the side surface of the end of the bottomed tubular member together with the housing from the outside.

[0009] ( 3 ) (1) above or (2 ), the bottomed tubular member has a first tubular portion arranged on the end side of the housing, a second tubular portion having a diameter larger than that of the first tubular portion, and a connecting portion connecting the first tubular portion and the second tubular portion, and it is preferable that at least one location where the diameter reduction processing is performed is located on the first tubular portion side of the connecting portion.

[0010] ( 4 ) above (1)~( 3 In the gas generator of item (1), it is preferable that the diameter-reducing process is carried out at two or more locations.

[0011] ( 5 ) The present invention teeth, a long cylindrical housing loaded with a gas generating agent that generates gas when burned, 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 part of the igniter and is fixed to one axial end of the housing; and a closing member that is fixed to the other axial end of the housing, wherein the closing member is fixed to the housing by deforming the side of a bottomed tubular member that is inserted partway into the housing from the other end of the housing together with the housing at at least one location from the exterior, and the closing member is fixed to the housing by reducing the diameter of the side of the bottomed tubular member from the exterior, and the reducing the diameter is performed at two or more locations, When the diameter reduction process is performed at two or more locations, a gap is formed between the inner wall of the housing and the outer wall of the closing member between adjacent locations of the diameter reduction process. It may also be .

[0012] ( 6 ) the above( 5 In the gas generator of item (1), the gap is preferably formed by reducing the diameter of adjacent positions to be reduced in the same process. [Effects of the Invention]

[0013] 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]

[0014] [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] 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 3] 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 4] FIG. 10 is a schematic diagram (partially omitted) showing the internal structure of a gas generator according to a fourth embodiment of the present invention, shown partially in cross section. [Figure 5] FIG. 10 is a schematic diagram (partially omitted) showing the internal structure of a gas generator according to a fifth embodiment of the present invention, shown partially in cross section. [Figure 6] 6(a) is a cross-sectional view (partially omitted) for explaining the diameter-reducing process of the gas generator of FIG. 5, and (b) and (c) are cross-sectional views (partially omitted) showing modified examples of (a). [Figure 7] 6 is an enlarged cross-sectional view of an end portion of the gas generator of FIG. 5. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] First Embodiment Hereinafter, with reference to FIG. 1, the internal structure of a cylinder-type gas generator according to an embodiment of the present invention will be described.

[0016] (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.

[0017] Housing 10 has peripheral walls 10a, 10e and is made of a long, cylindrical member having openings at both axial ends. Closure member 12 has an annular groove 13 formed by reducing the diameter of the peripheral surface of a bottomed, cylindrical member having a predetermined thickness by crimping (an example of a diameter-reducing processing method) described below, and is formed into a generally pot-shaped shape having internal space 12a. Annular groove 13 formed by crimping is formed so as to extend circumferentially on the peripheral surface of closing member 12. Gas outlets 11 are provided in the peripheral wall of housing 10 near the end on the side where closing member 12 is attached. 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.

[0018] The closing member 12 is made of a metal such as stainless steel, iron steel, aluminum alloy, or stainless alloy. As shown in Fig. 1, with a part of the closing member 12 inserted into one open end of the housing 10, the peripheral wall 10a of the housing 10, which corresponds to a part of the peripheral surface of the closing member 12, is narrowed radially inward (crimped) to form the annular groove 13, thereby crimping and fixing the closing member 12 to the housing 10.

[0019] 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.

[0020] 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 (not shown) is attached to the female connector. This retainer 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 the male connector from contact with terminal pin 52.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Squib cup 51 is generally made of metal or resin. A generally cylindrical member 53 covers the peripheral wall of squib cup 51 except for the vicinity of the tip, and is fixed to holder 20 by crimping together with igniter 50 via crimping portion 24. Generally cylindrical member 53 is a directional member that directs the direction of a flame generated in igniter 50 toward container 34 upon activation. A coil spring 54 is provided around squib cup 51 and generally cylindrical member 53, along the inner wall of housing 10. One end of this coil spring 54 abuts against an end of lid portion 34b of container 34, which will be described later, and the other end abuts against an end on the inner side of holder 20.

[0025] 1, a cylindrical container 34 in which a gas generating agent 31 and the like are sealed, and a filter 41 are loaded in the internal space of the housing 10 in parallel in the axial direction of the housing 10. The container 34 is preferably made of a metal such as aluminum.

[0026] The container 34 has a bottomed cylindrical portion 34a and a lid portion 34b, and contains therein a gas generating agent 31, a coil spring 35, an AI agent 32, and a cover member 33. The lid portion 34b and the tip of the igniter 50 are spaced a predetermined distance apart, which makes it easier for the squib cup 51 to split open when the igniter 50 is activated.

[0027] The gas generating agent 31 is an integrally molded product 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 product 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, basic metal carbonates such as 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.

[0028] 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 lid portion 34b, 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 container 34 by being sandwiched between the coil spring 35, the end of the filter 41 on the coil spring 35 side, and the bottom of the bottomed tubular portion 34a. Furthermore, because the coil spring 35 has a truncated cone shape as a whole from the igniter 50 side to the gas generating agent 31 side, it is possible to easily direct the direction of the flame emitted from the igniter 50 toward the gas generating agent 31.

[0029] The AI ​​agent 32 has an auto-ignition (AI) function that automatically ignites without the operation of the igniter 50. Explaining in more detail, the AI ​​agent 32 automatically ignites at a lower temperature than the gas generating agent 31, and therefore, in the unlikely event of a fire or the like occurring in a vehicle or the like equipped with an airbag system or the like incorporating the gas generator 100, it is possible to prevent the induction of abnormal operation of the gas generator 100 due to external heating. Furthermore, a cover member 33 that holds the AI ​​agent 32 is hermetically housed in the bottom of the container 34 on the closing member 12 side. The cover member 33 has a plurality of holes formed therein.

[0030] The filter 41 is a cylindrical member with a generally cylindrical hollow portion 41a at its center. Using the filter 41 made of the cylindrical member reduces the flow resistance of the working gas during operation, allowing for efficient gas flow. The filter 41 may be made of wire material made of metal, such as stainless steel or steel, or a wound or pressed mesh material. 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 container 34 by removing the high-temperature heat of the gas as it passes through the filter 41, and also as a removal means for removing slag and other contaminants contained in the gas. As a variation of the filter 41, a filter with a labyrinth-like flow path formed by combining generally cylindrical or cone-shaped metal components may be used. This allows the working gas to be redirected in various directions, thereby cooling the gas and removing slag.

[0031] 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.

[0032] 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.

[0033] A bottomed, cylindrical bypass prevention member 36 is provided between the filter 41 and the container 34 to axially separate the housing 10. The bypass prevention member 36 has a through-hole 36a at approximately the center of its bottom, through which the generated gas can pass. The bypass prevention member 36 covers the filter 41-side end of the bottomed, cylindrical portion 34a of the container 34 and its periphery, and is disposed so that its outer peripheral wall abuts against the inner wall of the housing 10. This prevents the generated gas from bypassing between the inner wall of the housing 10 and the outer peripheral portion of the filter 41 and leaking out to the gas outlet 11. In other words, the bypass prevention member 36 allows the gas generated on the container 34 side to flow into the filter 41 side through the through-hole 36a.

[0034] 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 flames flow from the tip of squib cup 51 of igniter 50 toward receiver 34 inside housing 10.

[0035] The flame that flows in in this way ruptures lid portion 34b of container 34, and further ignites and burns gas generating agent 31 inside container 34, generating a large amount of gas. This combustion of gas generating agent 31 increases the pressure inside container 34, and the generated gas ruptures the end of container 34 on the closing member 12 side and flows into hollow portion 41a and internal space 12a through through-hole 36a of bypass prevention member 36. Thereafter, the generated gas passes through filter 41 and is ejected from gas outlet 11 to the outside of gas generator 100, but because it passes through filter 41, the generated gas is cooled to a predetermined temperature. The gas ejected from gas outlet 11 is then guided into the interior of the airbag, inflating and deploying the airbag.

[0036] (Main features of the gas generator 100) According to the present embodiment, an object is to provide gas generator 100 which can be made lighter than when a conventional closing member is used, and in which costs are reduced by simplifying the components.

[0037] Furthermore, in this embodiment, since the closing member 12 and the housing 10 are both crimped, the crimping position is not particularly important as long as it allows the closing member 12 to be fixed to the housing 10. Therefore, there is no need to control the crimping position (such as accurate positioning) as much as in the past, which makes it possible to simplify the manufacturing process.

[0038] In addition, in this embodiment, since the closing member 12 has an internal space 12a, the spatial volume can be increased compared to when a conventional closing member is used, and the internal pressure when gas is generated can be reduced.

[0039] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 2. 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.

[0040] The gas generator 200 of this embodiment differs from the first embodiment in that a closing member 212 is used whose bottom is formed so as to be in approximately the same position as the end of the housing 210, instead of the closing member 12 of the first embodiment whose bottom protrudes from the end of the housing 10.

[0041] The blocking member 212 is formed so that its bottom is at approximately the same position as the end of the housing 210, but the side portion 212b is longer in the axial direction than the blocking member 12 of the first embodiment, and an internal space 212a with sufficient spatial volume is formed.

[0042] According to this embodiment, it is possible to achieve the same effects as those of the first embodiment. Furthermore, since the closing member 212 is formed so that its bottom is positioned substantially at the same position as the end of the housing 210, it is possible to ensure an internal space 212a with a sufficient spatial volume. This makes it possible to increase the spatial volume compared to when a conventional closing member is used, while keeping the overall axial length the same as or shorter than that of a conventional closing member, and thus to reduce the internal pressure when gas is generated.

[0043] Third Embodiment Next, a third embodiment of the present invention will be described with reference to Fig. 3. 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.

[0044] Gas generator 300 has an elongated, approximately cylindrical outer shape, and includes a housing 310, a holder 320 attached to one open end of housing 310, and a closing member 312 attached to the other end of housing 310 so as to close the other open end of housing 310.

[0045] Housing 310 has peripheral walls 310a, 310b, 310c, 310d, and 310e, and is made of a long, cylindrical member having openings at both axial ends. Closing member 312 has annular groove 313 formed by reducing the diameter of the peripheral surface of a bottomed, cylindrical member having a predetermined thickness by crimping, and is formed into a generally pot-shaped shape having internal space 312a. Annular groove 313 formed by crimping is formed so as to extend circumferentially on the peripheral surface of closing member 312. Gas outlets 311 are provided in the peripheral wall of housing 310 near the end on the side where closing member 312 is attached. Gas outlets 311 are holes for ejecting gas generated inside gas generator 300 to the outside, and a plurality of gas outlets 311 are provided along the circumferential and axial directions of housing 310.

[0046] Igniter 350 is held in a state where it is inserted into fitting portion 323 of holder 320.

[0047] Furthermore, the peripheral wall 310c of the housing 310, which corresponds to the squib cup 351 of the igniter 350, is tapered radially inward (by crimping) to form a cylindrical shape that matches the outer periphery of the squib cup 351, thereby crimping and fixing the squib cup 351 to the housing 310. As a result, the peripheral wall 310c can function as a directional member that directs the direction of the flame emitted from the tip of the igniter 350 toward the gas generating agent 331. Furthermore, the peripheral wall 310b of the housing 310 is formed in a shape that gradually reduces in diameter from the middle of the housing 310 toward the peripheral wall 310c. As a result, the peripheral wall 310b can position the end of the container 334, which will be described later, within the housing 310. Furthermore, the peripheral wall 310d of the housing 310 is formed in a tapered shape that expands in diameter from the peripheral wall 310c to the middle of the housing 310, following the outer shape of the squib cup 351. As a result, the squib cup 351 is sandwiched between the inner wall of the peripheral wall 310d and the fitting portion 323, and the igniter 350 can be fixed to the housing 310 and the holder 320.

[0048] A cylindrical container 334 in which a gas generating agent 331, a filter 341, and the like are sealed is loaded into the internal space of the housing 310. The container 334 is preferably made of a metal such as aluminum.

[0049] The container 334 has a bottomed cylindrical portion 334a and a lid portion 334b, and accommodates a gas generating agent 331, a coil spring 335, a filter 341, an AI agent 332, and a cover member 333 therein. The lid portion 334b ​​and the tip of the igniter 350 are spaced a predetermined distance apart, which makes it easier for the squib cup 351 to split open when the igniter 350 is activated.

[0050] The filter 341 is made of a cylindrical member having a generally cylindrical hollow portion 341a in the center, and the hollow portion 341a is filled with a gas generating agent 331. The AI ​​agent 332 has an auto-ignition (AI) function that automatically ignites without the activation of the igniter 350. A cover member 333 that holds the AI ​​agent 332 is hermetically housed between the filter 341 and the bottom of the container 334 on the closing member 312 side. The cover member 333 has a plurality of holes.

[0051] Next, the operation of gas generator 300 during activation described above will be described. When a vehicle equipped with an airbag device incorporating gas generator 300 in this embodiment collides, the collision is detected by collision detection means separately provided in the vehicle, and igniter 350 is activated based on this detection. When igniter 350 is activated, the pressure inside igniter 350 increases due to combustion of the ignition charge, causing the tip of squib cup 351 of igniter 350 to rupture, and flames flow from the tip of squib cup 351 of igniter 350 toward container 334 inside housing 310.

[0052] The flame flowing in in this manner cleaves open lid portion 334b ​​of container 334, and further ignites and burns gas generating agent 331 inside container 334, generating a large amount of gas. This combustion of gas generating agent 331 increases the pressure inside container 334, and the generated gas cleaves the end of container 334 on the closing member 312 side and flows into internal space 312a. Thereafter, the generated gas passes through filter 341 and cleaves the portion of container 334 that is in contact with gas outlet 311. Furthermore, as the portion of container 334 that is in contact with gas outlet 311 cleaves, the generated gas is ejected from gas outlet 311 to the outside of gas generator 300, but because it passes through filter 341, the generated gas is cooled to a predetermined temperature. Then, the gas ejected from gas outlet 311 is guided into the interior of the airbag to inflate and deploy the airbag.

[0053] According to this embodiment, it is possible to achieve the same effects as those of the first embodiment.

[0054] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described with reference to Fig. 4. In this embodiment, parts having the same reference numerals as those in the first or third embodiment down to the last two digits are similar to those in the first or third embodiment, and therefore their description may be omitted. Furthermore, parts not particularly described in this embodiment are similar to those in the first or third embodiment, and therefore their description and illustration may be omitted.

[0055] The gas generator 400 of this embodiment differs from the third embodiment in that, instead of the closing member 412 of the third embodiment, whose bottom part protrudes from the end of the housing 310, a closing member 412 whose bottom part only protrudes slightly from the end of the housing 410 is used.

[0056] The bottom of the blocking member 412 protrudes slightly from the end of the housing 410, but the side portion 412b is longer in the axial direction than the blocking member 312 of the third embodiment, and an internal space 412a with sufficient spatial volume is formed.

[0057] According to this embodiment, it is possible to achieve the same effects as in the first embodiment. Furthermore, since the bottom of the closing member 412 protrudes slightly from the end of the housing 410, it is possible to ensure an internal space 412a with sufficient spatial volume while maintaining the overall axial length the same as in the conventional case. This makes it possible to increase the spatial volume compared to when a conventional closing member is used while maintaining the overall axial length the same as in the conventional case, and to reduce the internal pressure when gas is generated.

[0058] Fifth Embodiment Next, a fifth embodiment of the present invention will be described with reference to Figures 5 to 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 unless otherwise specified, 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 first embodiment, and therefore their description and illustration may be omitted.

[0059] Gas generator 500 according to the present embodiment differs from the first embodiment mainly in the following points: (1) there are two diameter-reducing processes for fixing closing member 512 to the end of housing 510, (2) coil spring 535 is arranged so that one end abuts against the tip side (flame ejection side) of igniter 550, and is formed in a spiral shape that expands in diameter from one end side to the other end side, with gas generating agent 531 being pressed against bypass prevention member 536 at the other end side, and (3) there is no container. By providing a plurality of diameter-reducing processes (crimping processes) as in (1) above, the effect of preventing closing member 512 from coming off during gas generation is improved, and therefore the amount of deformation of housing 510 associated with diameter-reducing processes (crimping processes) can be reduced, and ultimately the effect of preventing housing 510 from breaking can be improved.

[0060] As shown in FIG. 6( a), the closing member 512 is formed by disposing a precursor 512A of the closing member 512, which is a bottomed tubular member, on the end of a precursor 510A of the housing. Then, a diameter-reducing process (such as crimping) is performed in the direction of the arrow at two locations simultaneously (including the case where two locations are processed at the same time in the same process) or one location at a time. This forms peripheral walls 510a and 510b and annular grooves 513 and 514 as shown in FIGS. 5 and 7, thereby fixing the closing member 512 to the housing 510. Furthermore, an annular gap 515 is preferably formed between the inner wall of the housing 510 and the outer wall of the closing member 512, between the annular grooves 513 and 514. The formation of the gap 515 allows stress due to the crimping process to be dispersed, thereby preventing breakage of the housing 510 due to the peripheral walls 510a and 510b or the annular grooves 513 and 514. In other words, for example, by forming gap 515, it is possible to realize a design that can prevent housing 510 from breaking during operation even if the thickness of housing 510 and / or blocking member 512 is made thinner than when gap 515 is not formed.

[0061] Here, as a modification of precursor 512A, precursors 612A and 712A of the blocking member as shown in FIGS. 6(b) and 6(c) may be used. Precursor 612A includes a first cylindrical portion 612a having a short, bottomed cylinder shape and disposed at the end of housing precursor 610A, a second cylindrical portion 612b having a larger diameter than first cylindrical portion 612a, and a connecting portion 612c connecting first cylindrical portion 612a and second cylindrical portion 612b. Connecting portion 612c is a cylindrical member whose diameter increases from the first cylindrical portion 612a side to the second cylindrical portion 612b side. Note that connecting portion 612c may have any shape as long as it connects first cylindrical portion 612a and second cylindrical portion 612b. For example, connecting portion 612c may be disk-shaped, and precursor 612A may be formed in a stepped shape. Precursor 712A includes a first cylindrical portion 712a with a bottom and disposed at the end of housing precursor 710A, a second cylindrical portion 712b with a short cylindrical shape and a diameter larger than that of first cylindrical portion 712a, and a connecting portion 712c connecting first cylindrical portion 712a and second cylindrical portion 712b. Connecting portion 712c is a cylindrical member whose diameter increases from the first cylindrical portion 712a side to the second cylindrical portion 712b side. Connecting portion 712c may have any shape as long as it connects first cylindrical portion 712a and second cylindrical portion 712b. For example, connecting portion 712c may be disk-shaped, with precursor 712A formed in a stepped shape. Using these modified precursors 612A and 712A facilitates diameter reduction. Furthermore, by providing connecting portion 612c that forms a step between first cylindrical portion 612a and second cylindrical portion 612b, and connecting portion 712c that forms a step between first cylindrical portion 712a and second cylindrical portion 712b, respectively, diameter reduction processing is performed at the upper arrow portion of Fig. 6(b) and the lower arrow portion of Fig. 6(c), whereby the formed reduced diameter portions (crimped portions) have shapes that conform to connecting portion 612c and connecting portion 712c, and the holding force between the closing member (bottomed cylindrical member) and the housing is increased compared to when the above-mentioned closing member 512 is employed. In other words, when precursors 612A, 712A are used instead of precursor 512A, it is possible to better prevent the closing member (bottomed cylindrical member) from falling off during operation of the gas generator.

[0062] The coil spring 535 is configured so that the end on the gas generating agent 531 side forms a spiral plane, which also serves as a base for attaching the AI ​​agent 532. The bypass prevention member 536 is fixed to the housing 510 via a welded portion 510c.

[0063] First holder 520 is a substantially cylindrical member made of resin, and has an annular groove 522 on its outer periphery. First holder 520 is fixed to housing 510 by performing a diameter reduction process (such as crimping) from the outer periphery of housing 510 to the inside at a position corresponding to annular groove 522, thereby forming peripheral wall 510e.

[0064] Second holder 525 is a generally cylindrical metal member, into which a portion (mainly the main body portion) of igniter 550 is inserted, and a portion of its exterior is inserted into first holder 520. Igniter 550 is fixed to second holder 525 by crimping with crimping portion 524. Second holder 525 is sandwiched between first holder 520 and third holder 555, and peripheral walls 510d and 510e, which will be described later, are formed, thereby fixing second holder 525 to housing 510.

[0065] Third holder 555 is a substantially cylindrical member made of resin, and has annular groove 556 on its outer periphery. Third holder 555 is fixed to housing 510 by performing diameter reduction processing (such as crimping) from the outer periphery of housing 510 to the inside at a position corresponding to annular groove 556, thereby forming peripheral wall 510d. Third holder 555 has inserted therein a part of igniter 550 (mainly squib cup 551) and crimped portion 524. Third holder 555 is also a directional member that directs the direction of a flame generated in igniter 550 when activated toward gas generating agent 531.

[0066] Igniter 550 is held and fixed to housing 510 by first holder 520, second holder 525, and third holder 555.

[0067] According to this embodiment, it is possible to achieve the same effects as in the first embodiment, and also to better prevent the closing member 512 from falling off during operation.

[0068] 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.

[0069] For example, in the first to fourth embodiments, the gas generator may not be provided with a container. Also, in the third and fourth embodiments, the gas generating agent may not be filled in the hollow portion of the filter. Also, in the fifth embodiment, the bypass member may be eliminated and the gas generating agent may be filled in the hollow portion of the filter.

[0070] Furthermore, in the first to fifth embodiments, the method of reducing the diameter of the housing has been described by taking caulking as an example, but any processing method that can reduce the diameter of the housing may be used. [Explanation of symbols]

[0071] 10, 210, 310, 410, 510 Housing 10a, 10e, 210a, 310a, 310b, 310c, 310d, 310e, 410a, 510a, 510b, 510d, 510e Peripheral wall 11, 211, 311, 411, 511 Gas outlet 12, 212, 312, 412, 512 Closure member 12a, 212a, 312a, 412a, 512a Interior space 13, 22, 213, 313, 322, 413, 513, 514, 522, 556 Annular groove 20, 320 holder 21, 23, 321, 323, 521, 523 Mating part 31, 331, 431, 531 Gas Generator 32, 332, 532 AI agents 33, 333 Cover member 34, 334, 434 containers 34a, 334a, 434a Bottomed cylindrical part 34b, 334b ​​Lid 35, 54, 335, 535 coil spring 36, 536 Bypass prevention member 41, 241, 341, 441, 541 filters 41a, 241a, 341a, 441a, 541a Hollow part 50, 350, 550 igniter 51, 351, 551 Squib Cup 52, 352, 552 terminal pins 53 Approximately cylindrical member 100, 200, 300, 400, 500 Gas Generator 212b, 412b side part 510A, 512A, 610A, 612A, 710A, 712A precursors 515 Gap 520 First Holder 525 Second Holder 555 3rd Holder 612a, 712a First cylindrical portion 612b, 712b Second cylindrical portion 612c, 712c joint

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; Equipped with the closing member is a bottomed tubular member inserted partway into the housing from the other end of the housing, and the side surface of the bottomed tubular member is subjected to diameter reduction processing from the outside together with the housing at at least one location, thereby deforming the closing member together with the housing and fixing it to the housing, a closing member that closes the bottom of the cylindrical member after deformation and that closes the bottom of the cylindrical member after deformation, and that closes the bottom of the cylindrical member after deformation, and that closes the bottom of the cylindrical member after deformation.

2. 2. The gas generator according to claim 1, wherein the bottomed tubular member is fixed to the housing by reducing the diameter of a side surface of the end of the bottomed tubular member together with the housing from the outside.

3. the bottomed tubular member has a first tubular portion disposed on an end side of the housing, a second tubular portion having a diameter larger than that of the first tubular portion, and a connecting portion connecting the first tubular portion and the second tubular portion, 3. The gas generator according to claim 1, wherein at least one location where the diameter-reducing process is performed is located on the first cylindrical portion side of the connecting portion.

4. 4. The gas generator according to claim 1, wherein the diameter-reducing process is performed at two or more locations.

5. A long cylindrical housing loaded with a gas generating agent that generates gas by burning, 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 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; Equipped with the closing member is a bottomed tubular member inserted partway into the housing from the other end of the housing, and the side surface of the bottomed tubular member is subjected to diameter reduction processing from the outside together with the housing at at least one location, thereby deforming the closing member together with the housing and fixing it to the housing, The diameter reduction process is performed at two or more locations, a gas generator characterized in that, when the diameter reduction processing is performed at two or more locations, a gap is formed between the inner wall of the housing and the outer wall of the blocking member between adjacent locations of the diameter reduction processing.

6. 6. The gas generator according to claim 5, wherein the gap is formed by reducing the diameter of adjacent portions of the reduced diameter machining in the same process.

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