Gas generator

Abstract

To provide a gas generator which prevents damage of a stored object, and thereby improves durability.SOLUTION: A gas generator 1A includes a housing including a peripheral wall part 11, first and second storage elements 60 and 61, an elastic body 70 which is compressed and interposed between the storage elements, a first wall surface, and a second wall surface 52. The elastic body 70 includes first and second elastic parts 71 and 72 which are continuously provided and spiral. The first and second elastic parts 71 and 72 come in contact with the first and second storage elements 60 and 61. The first storage element 60 is fixed to the inside of the housing so as to be sandwiched between the first wall surface and the first elastic part 71, and the second storage element 61 is fixed to the inside of the housing so as to be sandwiched between the second wall surface 52 and the second elastic part 72. The gas generator 1A includes a stopper part 51a for restricting movement to the side of the second storage element 61 of the first elastic part 71 by the end on the side of the second storage element 61 of the first elastic part 71 coming in contact therewith.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a gas generator to be incorporated into an airbag device as an occupant protection device equipped in an automobile or the like, and particularly to a so-called cylinder-type gas generator having an elongated cylindrical outer shape that is suitably incorporated into a side airbag device or the like. [Background technology]

[0002] Airbag devices, which are passenger protection devices, have become widespread from the viewpoint of protecting passengers in automobiles, etc. Airbag devices are installed to protect passengers from impacts that occur during a vehicle collision, and the airbag instantly inflates and deploys during a vehicle collision, thereby acting as a cushion to support the passenger's body.

[0003] The gas generator is incorporated into this airbag device. When a vehicle crashes, the control unit energizes the igniter, which then generates a flame that burns the gas generating agent, instantly generating a large amount of gas, which inflates and deploys the airbag.

[0004] There are gas generators of various configurations based on specifications such as the installation position relative to a vehicle, etc., and gas output. One of these is what is called a cylinder-type gas generator. A cylinder-type gas generator has an elongated cylindrical outer shape and is suitably incorporated into a side airbag device, a curtain airbag device, a knee airbag device, a seat cushion airbag device, etc.

[0005] Typically, in a cylinder-type gas generator, an igniter is attached to one axial end of a housing, and a gas generating agent storage chamber containing a plurality of granular gas generating agents is provided on the one end side.

[0006] In recent years, a cylinder-type gas generator has become known that has a configuration in which a plurality of elements housed in a gas generating agent storage chamber are fixed inside the gas generating agent storage chamber by interposing elastic bodies such as coil springs between the elements.

[0007] An example of a document disclosing a cylinder-shaped gas generator having the above configuration is Japanese Patent Laid-Open No. 2022-102514 (Patent Document 1). In the cylinder-shaped gas generator disclosed in Patent Document 1, the autoignition agent and the gas generating agent are elastically biased by a coil spring interposed between them, thereby fixing them inside the gas generating agent storage chamber. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-102514 Summary of the Invention [Problem to be solved by the invention]

[0009] Here, if an unintended load is applied to a cylinder-shaped gas generator having the above-described configuration due to it being dropped during transportation, etc., the elastic body absorbs this load, thereby preventing damage to each of the above-described multiple elements.

[0010] However, if a load that is too great to be absorbed by the elastic body is applied to a cylinder-shaped gas generator, the load that the elastic body cannot absorb and the maximum reaction force of the elastic body will be applied to at least one of the above-mentioned multiple elements, which may cause damage to that element.

[0011] Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide a gas generator that has improved durability by preventing damage to the contents in advance. [Means for solving the problem]

[0012] A gas generator according to the present invention includes a housing, a first accommodating element, a second accommodating element, an elastic body, a first wall surface, and a second wall surface. The housing includes a cylindrical peripheral wall portion having one axial end and the other axial end. The first accommodating element is provided inside the housing. The second accommodating element is provided inside the housing and is located closer to the other end than the first accommodating element. The elastic body is provided inside the housing and interposed in a compressed state between the first accommodating element and the second accommodating element. The first wall surface is located on the opposite side of the other end from the first accommodating element and faces the other end. The second wall surface is located on the opposite side of the one end from the second accommodating element and faces the one end. The elastic body has a first spiral elastic portion and a second spiral elastic portion. The first elastic portion is in contact with the first accommodating element. The second elastic portion is provided contiguous with the first elastic portion, is located on the opposite side from the first accommodating element side as seen from the first elastic portion, and is in contact with the second accommodating element. The first accommodating element is fixed inside the housing by being sandwiched between the first wall surface and the first elastic portion. The second accommodating element is fixed inside the housing by being sandwiched between the second wall surface and the second elastic portion. The gas generator according to the present invention further includes a stopper portion that limits movement of the first elastic portion toward the second accommodating element side by abutting an end of the first elastic portion facing the second accommodating element.

[0013] The gas generator according to the present invention may further include an igniter and a partition member. In that case, the igniter may be assembled to the one end. Also, in that case, the partition member may divide the internal space of the housing in the axial direction of the peripheral wall portion so that a gas generating agent storage chamber capable of storing a gas generating agent is located on the one end side, and a filter chamber in which a filter is disposed is located on the other end side. Furthermore, in that case, the partition member may have an annular wall portion extending along the inner circumferential surface of the peripheral wall portion, and a partition portion closing an end portion of the annular wall portion on the other end side in the axial direction. Also, in that case, at least a portion of the first wall surface may be constituted by the igniter, and at least a portion of the second wall surface may be constituted by the partition portion. Furthermore, in that case, the stopper portion may be constituted by an end portion of the annular wall portion on the one end side in the axial direction.

[0014] In the gas generator according to the present invention, the elastic body may be configured by a coil spring formed by winding a metal wire. In that case, the outer size of the first elastic portion when viewed along the axial direction of the peripheral wall portion may be larger than the outer size of the second elastic portion when viewed along the axial direction of the peripheral wall portion. Furthermore, in that case, at least a part of the second elastic portion may be disposed inside the annular wall portion.

[0015] In the gas generator according to the present invention, the first storage element may comprise either a gas generating agent or a sealed container in which the gas generating agent is stored, and the second storage element may comprise either an autoignition agent, an autoignition agent cover, or zeolite. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a gas generator that has improved durability by preventing damage to the contents before it occurs. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic view of a cylinder-shaped gas generator according to an embodiment. [Figure 2] FIG. 2 is an enlarged view of the vicinity of the igniter shown in FIG. [Figure 3] FIG. 2 is an enlarged view of region III shown in FIG. [Figure 4] 2 is a schematic diagram showing an example of a state when an external load is applied to the cylinder-shaped gas generator of the coil spring shown in FIG. 1. FIG. [Figure 5] FIG. 10 is a partially enlarged view of a cylinder-shaped gas generator according to a first modified example. [Figure 6] FIG. 10 is a partially enlarged view of a cylinder-shaped gas generator according to a second modified example. [Figure 7] FIG. 11 is a partially enlarged view of a cylinder-shaped gas generator according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments shown below exemplify the case where the present invention is applied to a cylinder-type gas generator incorporated in a side airbag device. In the embodiments shown below, the same or common parts are designated by the same reference numerals in the drawings, and their description will not be repeated.

[0019] (Embodiment) Fig. 1 is a schematic diagram of a cylinder-shaped gas generator according to an embodiment. Fig. 2 is an enlarged view of the vicinity of the igniter shown in Fig. 1. Fig. 3 is an enlarged view of region III shown in Fig. 1. First, with reference to Figs. 1 to 3, the configuration of cylinder-shaped gas generator 1A according to the present embodiment will be described.

[0020] As shown in Figures 1 to 3, cylinder-shaped gas generator 1A has a long, columnar outer shape. Cylinder-shaped gas generator 1A has a long, substantially cylindrical housing whose both axial ends are closed. The housing includes housing main body 10, holder 20, closing member 30, and partition member 50. The outer shell of the housing is defined by housing main body 10, holder 20, and closing member 30.

[0021] The housing main body 10, the holder 20, and the closing member 30 accommodate internal components such as an igniter 40, a plurality of granular gas generating agents 60 (hereinafter also referred to simply as "gas generating agents 60"), an auto-ignition agent 61, a coil spring 70, and a filter 80, and in addition, the above-mentioned partition member 50, which is also an internal component, is disposed within the housing. A gas generating agent storage chamber S1 and a filter chamber S2 are located within the housing. The gas generating agent storage chamber S1 accommodates the gas generating agent 60, the auto-ignition agent 61, and the coil spring 70, which are among the above-mentioned internal components. The filter chamber S2 accommodates the filter 80.

[0022] The housing main body 10 constitutes the peripheral wall portion 11 of the housing and is made of a long cylindrical member. The peripheral wall portion 11 has one end and the other end in the axial direction, and these both end portions constitute open ends. The peripheral wall portion 11 includes both a portion that defines the gas generating agent storage chamber S1 and a portion that defines the filter chamber S2.

[0023] The housing body 10 may be made of a metal member such as stainless steel, iron steel, aluminum alloy, or stainless alloy, or may be made of a press-formed product formed into a cylindrical shape by pressing a rolled steel plate such as SPCE.The housing body 10 may also be made of an electric resistance welded pipe such as STKM.

[0024] In particular, when the housing body 10 is constructed from a press-formed rolled steel plate or an electric resistance welded pipe, the housing body 10 can be formed more cheaply and easily than when metal components such as stainless steel or steel are used, and the weight can be significantly reduced.

[0025] The holder 20 and the closing member 30 are made of metal members such as stainless steel, iron steel, aluminum alloy, stainless alloy, or the like.

[0026] 1 and 2, holder 20 is made of a substantially cylindrical member having a through-hole 21 extending in a direction parallel to the axial direction of peripheral wall 11, and is assembled to peripheral wall 11 so as to close one of a pair of open ends of peripheral wall 11. In detail, holder 20 is fixed to peripheral wall 11 by joining holder 20 and peripheral wall 11 at or near their contact portions by, for example, welding, with a portion of holder 20 inserted into the open end of peripheral wall 11.

[0027] As a result, a weld 91 extending circumferentially of the housing is provided at the axial end of the housing located on the open end side of the peripheral wall 11. The gap between the peripheral wall 11 and the holder 20 is filled with the weld 91. Therefore, the gap is sealed by the weld 91, making it possible to ensure airtightness in that portion. Note that electron beam welding, laser welding, resistance welding, or the like can be suitably used to weld the peripheral wall 11 and the holder 20 together.

[0028] The assembly structure of the holder 20 to the peripheral wall 11 is not limited to the above-described assembly structure, and other assembly structures may be adopted. In that case, airtightness between the peripheral wall 11 and the holder 20 can be ensured by providing an O-ring or the like at an appropriate position.

[0029] 1, the blocking member 30 is made of a substantially disk-shaped member and is assembled to the peripheral wall portion 11 so as to block the other of a pair of open ends of the peripheral wall portion 11. In detail, the blocking member 30 is inserted into the open end of the peripheral wall portion 11 so that one axial end face of the blocking member 30 is abutted against the filter 80, and is fixed to the peripheral wall portion 11 by joining the flange portion of the blocking member 30 to the peripheral wall portion 11 at or near the contact portion between them, for example, by welding or the like.

[0030] As a result, a weld 92 extending circumferentially of the housing is provided at the axial end of the housing located on the open end side of the peripheral wall 11. The gap between the peripheral wall 11 and the closing member 30 is filled with the weld 92. Therefore, the gap is sealed by the weld 92, making it possible to ensure airtightness in that portion. Note that electron beam welding, laser welding, resistance welding, or the like can be suitably used to weld the peripheral wall 11 and the closing member 30 together.

[0031] The assembly structure of the closing member 30 to the peripheral wall portion 11 is not limited to the assembly structure described above, and other assembly structures may be adopted. Furthermore, the peripheral wall portion 11 and the closing member 30 may not be separate bodies, but may be configured as a single member having a cylindrical shape with a bottom.

[0032] 1 and 2, the igniter 40 is supported by the holder 20 and is mounted to one axial end of the peripheral wall portion 11. The igniter 40 is for burning the gas generating agent 60 and is disposed so as to face the space inside the housing. As a result, the igniter 40 and the holder 20 are located on the opposite side of the other end of the peripheral wall portion 11 (i.e., the axial end of the housing on the side where the blocking member 30 is located) when viewed from the gas generating agent 60, and form a first wall surface facing the other end of the peripheral wall portion 11.

[0033] The igniter 40 has an ignition section 41 and a pair of terminal pins 42. The ignition section 41 includes a squib cup. A resistor (bridge wire) is attached inside the squib cup so as to connect to the pair of terminal pins 42. The squib cup is filled with an ignition charge so as to surround or be in contact with the resistor. A transfer charge may be loaded inside the squib cup as needed.

[0034] Resistors typically include nichrome wire or alloys containing platinum and tungsten. Ignition charges typically include ZPP (zirconium-potassium perchlorate), ZWPP (zirconium-tungsten-potassium perchlorate), and lead tricinate. Transfer charges include metal powder / oxidizer compositions such as B / KNO3, B / NaNO3, and Sr(NO3)2, titanium hydride / potassium perchlorate, and B / 5-aminotetrazole / potassium nitrate / molybdenum trioxide.

[0035] When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 42. This generates Joule heat in the resistor, causing the ignition charge to start burning. The high-temperature particles generated by the combustion split open the squib cup containing the ignition charge. The time from when the current flows through the resistor to when the igniter 40 is activated is generally less than 2 milliseconds if the resistor uses nichrome wire.

[0036] Igniter 40 is fixed to holder 20 by crimping portion 22 provided on holder 20. More specifically, holder 20 has crimping portion 22 for crimping and fixing igniter 40 at an axial end portion facing the interior space of the housing. Igniter 40 is inserted into through portion 21 and is fixed against the wall portion that defines through portion 21, and then crimping portion 22 is crimped, whereby igniter 40 is clamped and fixed within holder 20.

[0037] As a result, igniter 40 is assembled to holder 20 so that ignition portion 41 is positioned to protrude toward the inside of the housing. Therefore, when igniter 40 is activated, the ignition charge is ignited, causing the squib cup to split, and the squib cup opens as a result of this splitting.

[0038] A seal member 43 made of an O-ring or the like is interposed between holder 20 and igniter 40. The gap between holder 20 and igniter 40 is filled with seal member 43, thereby sealing the gap. This configuration makes it possible to ensure airtightness in that portion. Note that the assembly structure of igniter 40 is not limited to the assembly structure using crimped portion 22 described above, and other assembly structures may be adopted.

[0039] A recess 23 is provided at the axial end of holder 20 that is exposed to the outside, continuing from the above-mentioned through-hole 21. Recess 23 forms a female connector portion that receives a male connector (not shown) of a harness for connecting igniter 40 to a control unit (not shown). Terminal pin 42 of igniter 40 is positioned exposed within recess 23. The male connector is inserted into recess 23, which serves as the female connector portion. This establishes electrical continuity between the core wire of the harness and terminal pin 42.

[0040] 1 and 3, a partition member 50 is disposed at a predetermined position in the space inside the housing. The partition member 50 is a member for dividing the space inside the housing in the axial direction of the peripheral wall portion 11 so that the gas generating agent storage chamber S1 is located on one axial end side of the peripheral wall portion 11 and the filter chamber S2 is located on the other axial end side of the peripheral wall portion 11.

[0041] The partition member 50 has a cylindrical shape with a bottom, and is made of a metal member such as stainless steel, iron steel, aluminum alloy, or stainless alloy.

[0042] The partition member 50 has a substantially cylindrical plate-shaped annular wall portion 51 extending along the inner circumferential surface of the peripheral wall portion 11, and a substantially flat plate-shaped partition portion 52 closing one axial end of the annular wall portion 51. The annular wall portion 51 stands from the periphery of the partition portion 52 toward the gas generating agent storage chamber S1. In other words, the partition portion 52 closes one of a pair of axial ends of the annular wall portion 51 that is located on the other end side of the peripheral wall portion 11. The partition member 50 is arranged so that the main surface of the partition portion 52 facing the filter chamber S2 abuts against the filter 80.

[0043] The partition wall 52 of the partition 50 configured in this manner is located on the opposite side of one end of the peripheral wall 11 (i.e., the axial end of the housing on the side where the holder 20 is located) when viewed from the autoignition agent 61, and forms a second wall surface facing the one end of the peripheral wall 11. The autoignition agent 61 will be described in detail later.

[0044] Scores 52a are provided on the main surface of the partition wall portion 52 that contacts the filter 80. The scores 52a are intended to allow the partition wall portion 52 to break and form an opening as the internal pressure of the gas generating agent storage chamber S1 increases due to combustion of the gas generating agent 60, and are configured, for example, by a plurality of grooves that are provided radially so as to intersect with one another. The scores 52a are provided in a portion of the filter 80 that faces the hollow portion 81.

[0045] The partition member 50 is assembled by being inserted into the peripheral wall portion 11 and then joined to the peripheral wall portion 11. More specifically, the partition member 50 is press-fitted into the interior of the peripheral wall portion 11, and is fixed to the peripheral wall portion 11 by joining the annular wall portion 51 of the partition member 50 to the peripheral wall portion 11 at or near the contact portion between them, for example, by welding.

[0046] As a result, a weld 90 extending along the circumferential direction of the housing is provided in the portion of the housing corresponding to the portion into which the partition member 50 is inserted. The gap between the peripheral wall 11 and the partition member 50 is filled with the weld 90. As a result, the gap is sealed by the weld 90, making it possible to ensure airtightness in that portion. Note that electron beam welding, laser welding, resistance welding, or the like can be suitably used to weld the peripheral wall 11 and the partition member 50 together.

[0047] The assembly structure of the partition member 50 to the peripheral wall portion 11 is not limited to the assembly structure using press-fitting and welding described above, and other assembly structures may be adopted. In that case, airtightness between the peripheral wall portion 11 and the partition member 50 can be ensured by providing an O-ring or the like at an appropriate position.

[0048] Within the space inside the housing, a space sandwiched between the holder 20 and the partition member 50 (i.e., the gas generating agent storage chamber S1) contains a plurality of granular gas generating agents 60, an autoignition agent 61, and a coil spring 70. In this embodiment, the gas generating agent 60 corresponds to the first storage element, the autoignition agent 61 corresponds to the second storage element, and the coil spring 70 corresponds to the elastic body.

[0049] The plurality of granular gas generating agents 60 are arranged on the side of the gas generating agent storage chamber S1 where the holder 20 and the igniter 40 are located. The autoignition agent 61 is arranged so as to abut against the main surface of the partition wall portion 52 on the side facing the gas generating agent storage chamber S1. In other words, the autoignition agent 61 is located closer to the other end of the peripheral wall portion 11 than the gas generating agents 60 (i.e., closer to the axial end of the housing where the blocking member 30 is located). The coil spring 70 is arranged between the gas generating agents 60 and the autoignition agent 61.

[0050] The gas generating agent 60 is an agent that generates gas by being ignited by hot particles generated by the activation of the igniter 40 and burning. A non-azide gas generating agent is preferably used as the gas generating agent 60. The gas generating agent 60 is generally configured as a molded body containing fuel, an oxidizer, and an additive.

[0051] The fuel may be, for example, a triazole derivative, a tetrazole derivative, a guanidine derivative, an azodicarbonamide derivative, a hydrazine derivative, or a combination thereof. In particular, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, or the like is preferably used.

[0052] Examples of oxidizing agents include basic metal salts 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 nitrates include sodium nitrate and potassium nitrate.

[0053] Examples of additives include binders, slag formers, and combustion adjusters. Suitable binders include organic binders such as metal salts of carboxymethyl cellulose and stearates, and inorganic binders such as synthetic hydrotalcite and acid clay. Suitable slag formers include silicon nitride, silica, and acid clay. Suitable combustion adjusters include metal oxides, ferrosilicon, activated carbon, and graphite.

[0054] The shape of the molded body of the gas generating agent 60 may be various, including granular, pellet-like, cylindrical, or other granular shapes, as well as disk-like shapes. For cylindrical molded bodies, perforated molded bodies having through holes inside the molded body (for example, a single-hole cylindrical shape or a multi-hole cylindrical shape) are also used. These shapes are preferably selected appropriately depending on the specifications of the airbag device into which the cylindrical gas generator 1A is to be incorporated, and it is preferable to select the optimal shape depending on the specifications, such as a shape in which the rate of gas generation changes over time when the gas generating agent 60 is burned. In addition to the shape of the gas generating agent 60, it is preferable to select the size and filling amount of the molded body appropriately taking into consideration the linear burning velocity, pressure exponent, etc. of the gas generating agent 60.

[0055] The autoignition agent 61 is made of pellets formed into a flat, generally cylindrical shape. The autoignition agent 61 is disposed on the opposite side of the coil spring 70 from the side on which the gas generating agent 60 is located (i.e., on the filter 80 side). The autoignition agent 61 is disposed on the radial center side of the peripheral wall portion 11 with its axial end face in contact with a second elastic portion 72 of the coil spring 70, which will be described later. The shape of the autoignition agent 61 is not particularly limited to a flat, generally cylindrical shape, and can be modified in various ways.

[0056] The autoignition agent 61 is held by being sandwiched between the partition wall portion 52 of the partition member 50 and the coil spring 70. As a result, the autoignition agent 61 is separated from the gas generating agent 60 by the coil spring 70.

[0057] Auto-ignition agent 61 is an agent that ignites automatically without the operation of igniter 40. More specifically, auto-ignition agent 61 spontaneously ignites at a lower temperature than gas generating agent 60, and is intended to prevent abnormal operation of cylinder-shaped gas generator 1A even if cylinder-shaped gas generator 1A is heated from the outside in the unlikely event of a fire or the like occurring in a vehicle or the like equipped with an airbag device incorporating cylinder-shaped gas generator 1A.

[0058] As shown in Figures 1 and 3, the coil spring 70 is provided for the purpose of preventing the gas generating agent 60, which is made of a molded body, from being crushed by vibration, etc., and is made by winding a metal wire in a spiral shape.

[0059] The coil spring 70 has a spiral first elastic portion 71 located on the gas generating agent 60 side and a spiral second elastic portion 72 located on the autoignition agent 61 side. The second elastic portion 72 is located on the opposite side of the first elastic portion 71 from the gas generating agent 60 side, and is disposed inside the annular wall portion 51 of the partition member 50.

[0060] The first elastic portion 71 further includes a first portion 71a located on the gas generating agent 60 side and a second portion 71b located on the second elastic portion 72 side. The second portion 71b is located between the first portion 71a and the second elastic portion 72 in the axial direction of the peripheral wall portion 11 and is provided contiguous with both of them. In other words, the second elastic portion 72 is provided contiguous with the first elastic portion 71.

[0061] The end portion of the first part 71a of the first elastic part 71 located on the gas generating agent 60 side and the end portion of the second elastic part 72 located on the autoignition agent 61 side are configured to have an approximately circular plate-like shape overall when viewed along the axial direction of the peripheral wall part 11, by arranging one end of the metal wire in a spiral shape at a predetermined interval.

[0062] The end of the first portion 71a configured in this manner, which is located on the gas generating agent 60 side, is in contact with the gas generating agent 60. In addition, the end of the second elastic portion 72, which is located on the autoignition agent 61 side, is in contact with the autoignition agent 61.

[0063] The outer size of the second portion 71b of the first elastic portion 71 when viewed along the axial direction of the peripheral wall portion 11 is larger than both the outer size of the first portion 71a of the first elastic portion 71 when viewed along the axial direction and the outer size of the second elastic portion 72 when viewed along the axial direction. In other words, the outer size of the first elastic portion 71 when viewed along the axial direction is larger than the outer size of the second elastic portion 72 when viewed along the axial direction.

[0064] Furthermore, the external size of the first portion 71a of the first elastic portion 71 when viewed along the axial direction is the same as the external size of the second elastic portion 72 when viewed along the axial direction. Therefore, the coil spring 70 has a plane-symmetrical structure with respect to a plane located at the center of the coil spring 70 in the axial direction. This eliminates the need to distinguish between the front and back of the coil spring 70 when assembling the coil spring 70.

[0065] Here, the coil spring 70 is placed between the autoignition agent 61 and the gas generating agent 60, and is thereby placed in a compressed state. Therefore, the gas generating agent 60 is elastically biased toward the igniter 40 side while being separated from the autoignition agent 61 by the first elastic portion 71 via the second elastic portion 72. As a result, the gas generating agent 60 is fixed inside the gas generating agent storage chamber S1 by being sandwiched between the igniter 40, the holder 20, and the first elastic portion 71. Therefore, with this configuration, it is possible to prevent the gas generating agent 60, which is made of a molded body, from being crushed by vibration or the like.

[0066] Furthermore, the autoignition agent 61 is elastically biased toward the partition wall 52 side while being separated from the gas generating agent 60 by the second elastic portion 72 via the first elastic portion 71. As a result, the autoignition agent 61 is fixed inside the gas generating agent storage chamber S1 by being sandwiched between the main surface of the partition wall 52 on the side facing the gas generating agent storage chamber S1 and the second elastic portion 72. Therefore, with this configuration, the autoignition agent 61 made of a molded body can be prevented from being crushed by vibration or the like.

[0067] Furthermore, when assembling the coil spring 70, the coil spring 70 is sandwiched and compressed between the auto-ignition agent 61 and the gas generating agent 60, which allows the coil spring 70 to absorb dimensional variations in the various components housed inside the housing.

[0068] 1 and 3, in cylinder-shaped gas generator 1A according to the present embodiment, the end of annular wall portion 51 in the axial direction of peripheral wall portion 11 opposite partition wall portion 52 (i.e., the end on the gas generating agent 60 side) forms stopper portion 51a that abuts against the end of second portion 71b of first elastic portion 71 on the autoignition agent 61 side. By configuring in this manner, it is possible to prevent damage to autoignition agent 61 as the content contained in cylinder-shaped gas generator 1A, and this point will be described in detail later.

[0069] 1, a filter 80 is disposed in the space within the housing, which is sandwiched between the closing member 30 and the partition member 50 (i.e., the filter chamber S2). The filter 80 is a cylindrical member having a hollow portion 81 extending in a direction parallel to the axial direction of the housing body 10. One axial end face of the filter 80 abuts against the closing member 30, and the other axial end face of the filter 80 abuts against the partition member 50.

[0070] The filter 80 functions as a cooling means for cooling the gas by removing the high temperature heat of the gas generated by the combustion of the gas generating agent 60 as the gas passes through the filter 80, and also functions as a removal means for removing slag (residue) and the like contained in the gas. As described above, by using the filter 80 made of a cylindrical member, the flow resistance to the gas flowing through the filter chamber S2 during operation is kept low, making it possible to achieve an efficient gas flow.

[0071] The filter 80 can be preferably made of an assembly of metal wire or metal mesh material made of stainless steel, iron, etc. In particular, a knitted wire mesh, a plain woven wire mesh, an assembly of crimped woven metal wire, or a combination of these compressed by a press can be used.

[0072] A wound perforated metal plate or the like can also be used as the filter 80. In this case, examples of the perforated metal plate that can be used include expanded metal, which is made by cutting staggered slits in a metal plate and expanding the slits to form holes and process it into a mesh-like shape, and hook metal, which is made by drilling holes in a metal plate and flattening the burrs that form around the holes by crushing them.

[0073] Here, the filter 80 is disposed at a distance from the peripheral wall 11 of the portion that defines the filter chamber S2 so that a gap 82 of a predetermined size is formed between the filter 80 and the peripheral wall 11 of that portion. By providing this gap 82, the gas generated by the combustion of the gas generating agent 60 passes through almost the entire area of ​​the filter 80, and the utilization efficiency of the filter 80 can be improved.

[0074] A plurality of gas outlets 12 are provided along the circumferential and axial directions on the peripheral wall 11 of the portion defining the filter chamber S2. These gas outlets 12 are for directing the gas that has passed through the filter 80 to the outside of the housing.

[0075] Next, with reference to Figs. 1 to 3, an operation during operation of cylinder-shaped gas generator 1A according to the present embodiment will be described.

[0076] Referring to Figures 1 to 3, when a vehicle equipped with cylinder-shaped gas generator 1A according to this embodiment collides, the collision is detected by collision detection means provided separately in the vehicle, and based on this, igniter 40 is activated by current supplied from a control unit provided separately in the vehicle.

[0077] When the igniter 40 is activated, the ignition charge and / or the transfer charge combusts, causing the pressure inside the ignition section 41 to rise, which causes the squib cup of the ignition section 41 to split, and thermal particles generated by the combustion of the ignition charge and / or the transfer charge flow out of the ignition section 41. The thermal particles that reach the gas generating agent 60 combust the gas generating agent 60. This generates a large amount of gas inside the gas generating agent storage chamber S1.

[0078] As a result, the pressure in the gas generating agent storage chamber S1 increases, and when the internal pressure of the gas generating agent storage chamber S1 reaches a predetermined pressure, a rupture occurs in the portion of the partition member 50 where the score 52a is provided. As a result, an opening is formed in the partition member 50 in the portion facing the hollow portion 81 of the filter 80, and the gas generating agent storage chamber S1 and the filter chamber S2 come into communication with each other via the opening.

[0079] As a result, the gas generated in the gas generating agent storage chamber S1 flows into the filter chamber S2 through the opening formed in the partition member 50. The gas that has flowed into the filter chamber S2 flows axially through the hollow portion 81 of the filter 80, then changes direction in the radial direction, and flows through the interior of the filter 80. During this process, the filter 80 removes heat to cool the gas, and the filter 80 removes slag contained in the gas.

[0080] The gas that has passed through filter 80 is then ejected to the outside of the housing through gas ejection port 12 provided in peripheral wall portion 11. The ejected gas is introduced into the interior of an airbag provided adjacent to cylinder-shaped gas generator 1A, and inflates and deploys the airbag. Note that autoignition agent 61 burns together with gas generating agent 60 when it is burned.

[0081] Here, in cylinder-shaped gas generator 1A according to the present embodiment, as described above, the end of annular wall portion 51 in the axial direction of peripheral wall portion 11 opposite partition wall portion 52 forms stopper portion 51a that abuts against the end of second part 71b of first elastic portion 71 on the autoignition agent 61 side.

[0082] By configuring in this manner, it is possible to prevent damage to the contents of cylinder-shaped gas generator 1A. This point will be described in detail below with reference to Fig. 4 and the above-mentioned Fig. 3. Fig. 4 is a schematic diagram showing an example of a state when an external load is applied to the cylinder-shaped gas generator shown in Fig. 1.

[0083] As shown in FIG. 4, when an external load is applied to cylinder-shaped gas generator 1A in the axial direction of peripheral wall portion 11 from the gas generating agent storage chamber S1 side toward the filter chamber S2 side (see arrow AR1 in the figure), first elastic portion 71 of coil spring 70 deforms so as to be further compressed from the state before the load is applied (see FIG. 3).

[0084] As described above, the first elastic portion 71 and the second elastic portion 72 are provided continuously. Therefore, if no measures are taken, not only the first elastic portion 71 but also the second elastic portion 72 will be deformed so as to be further compressed from the state before the load is applied, and as a result, an excessive load resulting from the elastic force of the first elastic portion 71 and the elastic force of the second elastic portion 72 will be applied to the autoignition agent 61, which may cause the autoignition agent 61 to pulverize.

[0085] In this regard, in cylinder-shaped gas generator 1A according to the present embodiment, the end of second portion 71b of first elastic portion 71 on the autoignition agent 61 side abuts against stopper portion 51a. By being configured in this manner, movement of first elastic portion 71 toward the autoignition agent 61 side beyond stopper portion 51a is restricted by stopper portion 51a.

[0086] As a result, the transmission of the load from the first elastic portion 71 to the second elastic portion 72 is suppressed, and as described above, it is possible to prevent the second elastic portion 72 from further compressively deforming in conjunction with the compressive deformation of the first elastic portion 71. In other words, with the above configuration, it is possible to effectively prevent a load greater than a preset load from being unintentionally applied to the auto-ignition agent 61.

[0087] As a result, even when a load of a magnitude that cannot be absorbed by coil spring 70 is applied to cylinder-shaped gas generator 1A, autoignition agent 61 can be effectively prevented from being powdered.

[0088] Therefore, by configuring cylinder-shaped gas generator 1A according to the present embodiment, damage to the contents can be prevented in advance, resulting in a gas generator with improved durability.

[0089] In the above-described embodiment, the coil spring 70 as an elastic body is explained as being formed by winding a metal wire, but the coil spring 70 may also be formed by winding a wire made of, for example, rubber or resin.

[0090] Furthermore, in the above-described embodiment, the first elastic portion 71 of the coil spring 70 includes the first portion 71a and the second portion 71b that have different external sizes when viewed along the axial direction of the peripheral wall portion 11. However, the first elastic portion 71 does not necessarily have to include multiple portions with different external sizes. The first elastic portion 71 may be configured, for example, so that all of the first elastic portion 71 has the same external size as the second portion 71b. In other words, the first elastic portion 71 may not include the first portion 71a, and the end of the second portion 71b located on the opposite side to the autoignition agent 61 may be in contact with the gas generating agent 60.

[0091] Furthermore, in the above-described embodiment, the stopper portion that limits the movement of the first elastic portion 71 toward the autoignition agent 61 is configured by the end portion of the annular wall portion 51 on the side opposite to the partition wall portion 52, but the stopper portion is not particularly limited to this configuration. For example, the stopper portion may be configured by a crimped portion that is formed on the peripheral wall portion 11 by reducing the diameter of a predetermined position of the peripheral wall portion 11 toward the inside in the radial direction, or may be configured by a protrusion that is formed by a weld bead or the like at a predetermined position on the inner surface of the peripheral wall portion 11.

[0092] In addition, in the above-described embodiment, an example has been given of the case where the first elastic portion 71 and the second elastic portion 72 of the coil spring 70 are configured such that, when viewed along the axial direction of the peripheral wall portion 11, the metal wire is arranged in a spiral shape at a predetermined interval, thereby giving a part of the elastic portion an approximately circular plate shape including a surface perpendicular to the axial direction. However, the first elastic portion 71 and the second elastic portion 72 may also be configured such that, for example, the metal wire is arranged approximately parallel at a predetermined interval, giving a part of the elastic portion an approximately circular plate shape as a whole.

[0093] Furthermore, in the above-described present embodiment, the case where the gas generating agent 60 is exposed inside the gas generating agent storage chamber S1 has been exemplified, but from the viewpoint of preventing the gas generating agent 60 from absorbing moisture, the gas generating agent 60 may be stored in a sealed container inside the gas generating agent storage chamber S1. In this case, it is preferable that the sealed container be made of a relatively fragile material that melts or bursts due to heat or pressure generated by activation of the igniter 40. In this case, the sealed container corresponds to the first storage element that contacts the first elastic portion 71 of the coil spring 70.

[0094] Furthermore, in the present embodiment described above, the case where the second containing element fixed inside the gas generating agent containing chamber S1 by the coil spring 70 is the autoignition agent 61 has been exemplified, but the second containing element is not particularly limited to this. This point will be described in detail in a modified example based on the present embodiment described later.

[0095] (First and second modified examples) Fig. 5 is a partially enlarged view of a cylinder-shaped gas generator according to a first modified example. Fig. 6 is a partially enlarged view of a cylinder-shaped gas generator according to a second modified example. Hereinafter, cylinder-shaped gas generators 1A1, 1A2 according to first and second modified examples based on the above-described embodiment will be described with reference to Figs. 5 and 6. Note that Figs. 5 and 6 respectively show cylinder-shaped gas generators 1A1, 1A2 at positions corresponding to the partially enlarged view shown in Fig. 3.

[0096] As shown in FIG. 5, when compared with cylinder-shaped gas generator 1A according to the embodiment described above, cylinder-shaped gas generator 1A1 according to the first modified example differs only in the configuration of the second accommodating element fixed inside gas generating agent accommodating chamber S1.

[0097] More specifically, in cylinder-shaped gas generator 1A1, zeolite 100 is fixed between second elastic portion 72 of coil spring 70 and partition wall portion 52 of partition member 50 in place of autoignition agent 61. Zeolite 100 functions as a desiccant, and has a particulate shape such as granules, pellets, or cylinders. In this modification, zeolite 100 corresponds to the second storage element.

[0098] As shown in FIG. 6, when compared with cylinder-shaped gas generator 1A according to the embodiment described above, cylinder-shaped gas generator 1A2 according to the second modified example differs only in the configuration of the second accommodating element fixed inside gas generating agent accommodating chamber S1.

[0099] More specifically, in cylinder-shaped gas generator 1A2, zeolite 100 is fixed in addition to autoignition agent 61 between second elastic portion 72 of coil spring 70 and partition wall portion 52 of partition member 50. Zeolite 100 is located between autoignition agent 61 and second elastic portion 72. In this modification, zeolite 100 corresponds to the second containing element.

[0100] Even when configured in this manner, effects similar to those described in the above-mentioned embodiment can be obtained, and the gas generator can be made to have improved durability by preventing damage to the contents in advance.

[0101] (Third Modification) Fig. 7 is a partially enlarged view of a cylinder-shaped gas generator according to a third modified example. Hereinafter, cylinder-shaped gas generator 1A3 according to the third modified example based on the embodiment described above will be described with reference to Fig. 7. Note that Fig. 7 shows cylinder-shaped gas generator 1A3 at a position corresponding to the partially enlarged view shown in Fig. 3.

[0102] As shown in FIG. 7, when compared with cylinder-shaped gas generator 1A according to the embodiment described above, cylinder-shaped gas generator 1A3 according to the third modified example differs only in the configuration of the second accommodating element fixed inside gas generating agent accommodating chamber S1.

[0103] More specifically, in cylinder-shaped gas generator 1A3, in addition to autoignition agent 61, autoignition agent cover 110 is fixed between second elastic portion 72 of coil spring 70 and partition wall portion 52 of partition member 50. Autoignition agent cover 110 is located between autoignition agent 61 and second elastic portion 72. In this modification, autoignition agent cover 110 corresponds to the second containing element.

[0104] Auto-ignition agent cover 110 has a positioning recess 111 in the portion of peripheral wall 11 that faces partition wall 52 of partition member 50 in the axial direction, and has a skirt-shaped fixing tubular portion 112 on its outer edge. One or more through holes 111a are provided in the bottom of positioning recess 111 of auto-ignition agent cover 110 to mutually communicate a pair of spaces partitioned by auto-ignition agent cover 110 (i.e., the space containing gas generating agent 60 and the space containing auto-ignition agent 61).

[0105] The auto-ignition agent cover 110 is preferably made of a metal press-molded product, for example, a brass member that will not break or melt even when the gas generating agent 60 is burned. However, the auto-ignition agent cover 110 does not necessarily have to be made of brass, and the auto-ignition agent cover 110 may also be made of stainless steel, steel, iron, aluminum, an aluminum alloy, or the like.

[0106] It should be noted that auto-ignition agent cover 110 does not necessarily need to be provided with through-hole 111a, and auto-ignition agent cover 110 may be configured to have scores so that through-holes are formed in auto-ignition agent cover 110 as gas generating agent 60 burns. Furthermore, auto-ignition agent cover 110 may not be provided with through-holes or scores, and auto-ignition agent cover 110 itself may be configured from a fragile material that breaks or melts when gas generating agent 60 burns.

[0107] The auto-ignition agent cover 110 is inserted into the annular wall portion 51 of the partition member 50, and the fixing tubular portion 112 of the auto-ignition agent cover 110 abuts against the inner circumferential surface of the annular wall portion 51. In other words, the auto-ignition agent cover 110 is press-fitted into the annular wall portion 51 of the partition member 50, thereby fixing the auto-ignition agent cover 110 to the partition member 50.

[0108] A portion of the autoignition agent 61 is accommodated in the positioning recess 111 provided in the autoignition agent cover 110. As a result, the autoignition agent 61 is sandwiched between the bottom of the positioning recess 111 of the autoignition agent cover 110 and the partition wall 52 of the partition member 50. Therefore, the autoignition agent 61 comes into contact with both the autoignition agent cover 110 and the partition member 50.

[0109] When configured in this manner, the autoignition agent 61 comes into thermal contact with the peripheral wall portion 11 via the autoignition agent cover 110, which is a metal member, and the partition member 50, which is also a metal member, in essentially the shortest path.

[0110] Even when configured in this manner, effects similar to those described in the above-mentioned embodiment can be obtained, and the gas generator can be made to have improved durability by preventing damage to the contents in advance.

[0111] Furthermore, with this configuration, as described above, the auto-ignition agent 61 is in thermal contact with the peripheral wall portion 11 via substantially the shortest path. Therefore, in the event of a fire or the like occurring in a vehicle or the like, the timing of the occurrence of auto-ignition operation, which is initiated by the automatic ignition of the auto-ignition agent 61, is accelerated, and as a result, the temperature of the gas generating agent 60 when the auto-ignition operation occurs can be kept relatively low. Therefore, it is possible to significantly suppress an increase in the internal pressure of the housing during auto-ignition operation, resulting in an improvement in safety.

[0112] (Other forms, etc.) The characteristic configurations shown in the above-described embodiments of the present invention and their modifications can naturally be combined with one another within the scope of the gist of the present invention.

[0113] Furthermore, in the above-described embodiment of the present invention and its modified examples, the present invention has been described by way of example only as being applied to a cylinder-type gas generator incorporated in a side airbag device, but the application of the present invention is not limited to this, and the present invention can also be applied to cylinder-type gas generators incorporated in curtain airbag devices, knee airbag devices, seat cushion airbag devices, etc., and so-called T-shaped gas generators which have an elongated outer shape similar to a cylinder-type gas generator.

[0114] As such, the above-described embodiments and their modifications disclosed herein are illustrative in all respects and are not limiting. The technical scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0115] 1A, 1A1 to 1A3 Cylinder-shaped gas generator, 10 Housing body, 11 Peripheral wall portion, 12 Gas outlet, 20 Holder, 21 Penetration portion, 22 Crimping portion, 23 Recess, 30 Closure member, 40 Igniter, 41 Ignition portion, 42 Terminal pin, 43 Sealing member, 50 Partition member, 51 Annular wall portion, 51a Stopper portion, 52 Partition wall portion, 52a Score, 60 Gas generating agent, 61 Auto-ignition agent, 70 Coil spring, 71 First elastic portion, 71a First portion, 71b Second portion, 72 Second elastic portion, 80 Filter, 81 Hollow portion, 82 Gap portion, 90 to 92 Welded portion, 100 Zeolite, 110 Auto-ignition agent cover, 111 Positioning recess, 111a Through hole, 112 fixing cylinder, S1 gas generating agent storage chamber, S2 filter chamber.

Claims

1. a housing including a cylindrical peripheral wall portion having one axial end and the other axial end; a first receiving element provided inside the housing; a second receiving element provided inside the housing and positioned closer to the other end than the first receiving element; an elastic body provided inside the housing and interposed in a compressed state between the first housing element and the second housing element; a first wall surface located on the opposite side of the other end side as seen from the first housing element and facing the other end side; a second wall surface located on the opposite side of the one end side as viewed from the second containing element and facing the one end side; the elastic body has a spiral-shaped first elastic portion that contacts the first housing element, and a spiral-shaped second elastic portion that is provided continuously with the first elastic portion, is located on the opposite side to the first housing element as viewed from the first elastic portion, and contacts the second housing element, the first housing element is fixed inside the housing by being sandwiched between the first wall surface and the first elastic portion; the second housing element is fixed inside the housing by being sandwiched between the second wall surface and the second elastic portion, a stopper portion that limits movement of the first elastic portion toward the second accommodating element by abutting against an end of the first elastic portion toward the second accommodating element.

2. an igniter assembled to the one end; a partition member that partitions the internal space of the housing in the axial direction of the peripheral wall portion so that a gas generating agent storage chamber capable of storing a gas generating agent is located on the one end side and a filter chamber in which a filter is disposed is located on the other end side, the partition member has an annular wall portion extending along an inner circumferential surface of the circumferential wall portion, and a partition wall portion closing an end portion of the annular wall portion on the other end side in the axial direction, At least a portion of the first wall surface is formed by the igniter, At least a portion of the second wall surface is formed by the partition wall portion, 2. The gas generator according to claim 1, wherein the stopper portion is formed by an end portion of the annular wall portion on the one end side in the axial direction.

3. the elastic body is configured by a coil spring formed by winding a metal wire, an outer size of the first elastic portion when viewed along the axial direction of the peripheral wall portion is larger than an outer size of the second elastic portion when viewed along the axial direction of the peripheral wall portion, The gas generator according to claim 2 , wherein at least a portion of the second elastic portion is disposed inside the annular wall portion.

4. the first storage element is composed of either a gas generating agent or a sealed container in which the gas generating agent is stored, 4. The gas generator according to claim 1, wherein the second containing element is made of any one of an autoignition agent, an autoignition agent cover, and zeolite.

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