Gas generator

Abstract

A gas generator (1) is provided with a metal-made case main body (10), a retainer assembly (20), and an igniter (40). The retainer assembly (20) has a metal-made retainer portion (20A) that holds the igniter (40), and a resin-made connector portion (20B) that can receive a connector connected to a terminal pin (43) of the igniter (40). The retainer portion (20A) includes a cylindrical first body portion (21) and a ring-shaped protruding portion (22) that protrudes from the first body portion (21), and the connector portion (20B) includes a cylindrical second body portion (24) and a cylindrical portion (25) that is provided so as to extend from the second body portion (24). The cylindrical portion (25) is inserted in the case main body (10) and is externally inserted in the first body portion (21), a gap between the case main body (10) and the first body portion (21) is closed by the case main body (10) being reduced in diameter at a portion corresponding to the cylindrical portion (25), and the case main body (10) and the first body portion (21) being sandwiched and compressed by the reduced-diameter portion of the case main body (10) and the first body portion (21).

Description

Technical Field

[0001] The present invention relates to a gas generator installed in an airbag device, which is an occupant protection device equipped in automobiles and the like, and particularly to a so-called cylindrical gas generator with an elongated cylindrical shape suitable for installation in side airbag devices and the like. Background Technology

[0002] In the past, from the perspective of protecting occupants of automobiles and other vehicles, airbag devices have become increasingly popular as occupant protection devices. Airbag devices are equipped to protect occupants from the impact of a collision with a vehicle or other vehicle. By inflating and deploying the airbag instantly when a collision occurs, the airbag acts as a cushion to support the occupant's body.

[0003] A gas generator is a device installed in the airbag system that, upon collision with a vehicle or other object, uses power from the control unit to ignite the igniter, and the flame generated in the igniter ignites the gas generator to produce a large amount of gas instantly, thereby inflating and deploying the airbag.

[0004] Gas generators come in various structures based on their installation location relative to vehicles, output specifications, and other characteristics. One type is the cylindrical gas generator. Cylindrical gas generators are long and cylindrical in shape, suitable for installation in side airbags, curtain airbag apparatus, knee airbags, seat airbags, and the like.

[0005] Typically, in a cylindrical gas generator, an igniter is assembled at one axial end of the housing, and a combustion chamber containing a gas generating agent is provided at that end. A filter chamber containing a filter is provided at the other axial end of the housing, and a gas outlet is provided in the portion of the peripheral wall of the housing that defines the filter chamber.

[0006] In this cylindrical gas generator, the gas generated in the combustion chamber flows into the filter chamber along the axial direction of the casing and passes through the interior of the filter. The gas that has passed through the filter is then ejected to the outside through the gas outlet.

[0007] In addition, as a document that discloses a cylindrical gas generator having this structure, there is, for example, Japanese Patent Application Publication No. 2017-193191 (Patent Document 1).

[0008] In the cylindrical gas generator disclosed in Patent Document 1, a helical spring is provided between the aforementioned end of the housing where the igniter is assembled and the gas generating agent, applying force to the gas generating agent toward the other end of the housing. This helical spring is a component used to properly maintain the distance between the igniter assembled at the aforementioned end of the housing and the gas generating agent while fixing the gas generating agent inside the housing.

[0009] Furthermore, in the gas generator disclosed in Patent Document 1, a generally cylindrical metal combustion control shroud is provided at one end of the housing to cover the ignition part of the igniter, which houses the igniter propellant. This combustion control shroud is a component used to efficiently guide the hot particles generated in the igniter during operation to the gas generating agent; more specifically, it is a component that directs the direction of travel of the hot particles generated in the ignition part.

[0010] By making the gas generator into a cylindrical shape with this structure, good gas output characteristics can be obtained during operation.

[0011] In gas generators, it is generally important to keep the gas generating agent airtight from the outside. This is because if the gas generating agent absorbs moisture, the desired gas output characteristics may no longer be achieved.

[0012] In cylindrical gas generators, one method to prevent the gas generating agent from absorbing moisture is to contain the gas generating agent in a container, seal the container, and then place it inside a housing. This container is composed of fragile components that are susceptible to melting or rupture under the heat or pressure generated by the operation of an igniter. For example, Japanese Patent Application Publication No. 2018-69924 (Patent Document 2) discloses a cylindrical gas generator employing this method.

[0013] However, using the above method presents a challenge in terms of manufacturing cost. Specifically, the containers constructed from fragile parts have relatively high component costs. Furthermore, the operation of sealing the container after containing the gas generator requires considerable labor and time, thus increasing manufacturing costs in this respect as well.

[0014] On the other hand, in cylindrical gas generators, as another method to prevent the gas generating agent from absorbing moisture, there is a method of providing, for example, O-rings, sealing strips, etc., at various points on the housing to airtightly seal the combustion chamber containing the gas generating agent. For example, Japanese Patent Application Publication No. 2008-296763 (Patent Document 3) discloses a cylindrical gas generator employing this method.

[0015] In the cylindrical gas generator disclosed in Patent Document 3, the housing is configured to include a generally cylindrical housing body and a holder that holds the igniter and is inserted into the open end of the housing body. A sealing member, such as an O-ring, is sandwiched between the housing body and the holder. Furthermore, a sealing member, such as a sealing tape, is adhered to seal the communication hole of the component separating the combustion chamber and the filter chamber, thereby ensuring airtightness at these parts. Additionally, by employing this method, manufacturing costs can be reduced compared to using a sealed container.

[0016] Existing technical documents

[0017] Patent documents

[0018] Patent Document 1: Japanese Patent Application Publication No. 2017-193191

[0019] Patent Document 2: Japanese Patent Application Publication No. 2018-69924

[0020] Patent document 3: Japanese Patent Application Publication No. 2008-296763. Summary of the Invention

[0021] The problem that the invention aims to solve

[0022] However, in the cylindrical gas generator disclosed in the aforementioned patent document 3, the functions and characteristics of the retainer require holding the igniter, receiving the connector connected to the igniter, a firm connection with the housing body, and the strength to withstand the pressure rise in the combustion chamber during the operation of the gas generator. Therefore, the shape of the retainer is inevitably more complex, which in turn requires higher processing precision, resulting in higher component costs for the retainer.

[0023] Furthermore, since the retainer is a relatively large metal part, there is also the problem that the weight of the cylindrical gas generator will inevitably increase.

[0024] On the other hand, when a cylindrical gas generator, as disclosed in Patent Document 1, is constructed with a helical spring and a combustion control shroud, many parts need to be installed on the aforementioned end portion of the housing. This not only increases the number of parts but also complicates the assembly process, resulting in increased manufacturing costs. Furthermore, if the number of parts can be reduced, the overall weight reduction of the gas generator can also be achieved.

[0025] Therefore, the present invention was made to solve the above-mentioned problems, and the object is to provide a gas generator that achieves cost reduction and weight reduction.

[0026] Methods used to solve problems

[0027] The gas generator according to the present invention includes a housing body, a retainer assembly, and an igniter. The housing body is constructed of a cylindrical metal component that includes a combustion chamber containing a gas generating agent. The retainer assembly is inserted into an axially open end of the housing body and includes a hollow, through-hole-like opening extending in a direction parallel to the axial direction of the housing body. The igniter includes an ignition part containing an igniter propellant and a terminal pin connected to the ignition part. At least a portion of the ignition part is disposed inside the hollow opening when the ignition part is located on the combustion chamber side and the terminal pin is located on the opposite side of the combustion chamber side. The retainer assembly has a metal retainer part and a resin connector part. The retainer part is located on the combustion chamber side and receives and holds the igniter. The connector part is located on the opposite side of the combustion chamber side and is capable of receiving a connector connected to the terminal pin. The aforementioned retainer portion includes a cylindrical first body portion defining the aforementioned hollow opening and an annular protrusion protruding from the aforementioned first body portion along the radial direction of the aforementioned housing body. The aforementioned connector portion includes a cylindrical second body portion defining the aforementioned hollow opening and a cylindrical portion extending from the aforementioned second body portion toward the aforementioned combustion chamber side. The aforementioned cylindrical portion is inserted into the aforementioned open end of the aforementioned housing body and is externally inserted into the portion of the aforementioned first body portion located on the opposite side to the aforementioned combustion chamber side when viewed from the aforementioned annular protrusion. In the gas generator based on the present invention, by the radially inward reduction of the diameter of the portion of the aforementioned housing body corresponding to the aforementioned cylindrical portion, the aforementioned cylindrical portion is clamped and compressed by the reduced diameter portion of the aforementioned housing body and the aforementioned first body portion, thereby sealing the gap between the aforementioned housing body and the aforementioned first body portion by the aforementioned cylindrical portion.

[0028] In the gas generator based on the present invention described above, it is also possible to have an annular stepped surface connecting the inner circumferential surface of the second body portion to the inner circumferential surface of the cylindrical portion provided at the connector portion, with the inner diameter of the cylindrical portion being larger than the inner diameter of the second body portion. A first chamber defined by the annular stepped surface and the inner circumferential surface of the cylindrical portion is provided at the axial end of the connector portion located on the combustion chamber side. In this case, it is preferable that the first body portion is inserted into the first chamber, and the axial end face of the first body portion located on the side opposite to the combustion chamber side abuts against the annular stepped surface.

[0029] In the gas generator based on the present invention described above, the inner diameter of the second body portion may be larger than the inner diameter of the first body portion, and a second chamber may be provided at the axial end of the retainer assembly located on the side opposite to the combustion chamber side, defined by the axial end face of the first body portion located on the side opposite to the combustion chamber side and the inner circumferential surface of the second body portion. In this case, it is preferable that the second chamber constitutes a receiving portion of the connector that connects to the terminal pin.

[0030] In the gas generator based on the present invention described above, the outer peripheral surface of the first body portion may be tapered toward the combustion chamber side.

[0031] In the gas generator based on the present invention described above, it may also include: a filter disposed inside the housing body; and a partition member disposed inside the housing body, which divides the interior space of the housing body axially into a filter chamber containing the filter and a combustion chamber. In this case, the partition member may be fixed by welding to the housing body.

[0032] In the gas generator based on the present invention described above, a helical spring may also be included, which is clamped between the retainer assembly and the gas generating agent. By applying force to the gas generating agent toward the side opposite to the side where the retainer assembly is located while simultaneously moving the gas generating agent away from the ignition part, the gas generating agent is fixed inside the housing body. In this case, the ignition part may include a cup that cracks when the igniter is operated by the ignition propellant; furthermore, in this case, the helical spring may be arranged substantially coaxially with the ignition part, surrounding the ignition part without clamping other components between them, so that the opening state of the cup when it cracks is limited by the helical spring.

[0033] In the gas generator based on the present invention described above, the ignition part may be substantially cylindrical in shape. Alternatively, the helical spring may include a cylindrical portion and an expanded diameter portion. The cylindrical portion is located on the retainer assembly side and has a fixed inner diameter. The expanded diameter portion extends from the gas-generating agent side end of the cylindrical portion toward the gas-generating agent side, and its inner diameter increases as it approaches the gas-generating agent. In this case, it is preferable that the portion of the helical spring surrounding the igniter is composed of the cylindrical portion.

[0034] In the gas generator based on the present invention described above, it is preferable that the following conditions are met: the inner diameter of the portion of the housing body containing the gas generating agent is set to R1, the outer diameter of the ignition part is set to R2, the distance from the portion of the ignition part containing the igniting agent to the gas generating agent along the axial direction of the housing body is set to L1, the distance from the portion of the ignition part containing the igniting agent to the boundary between the cylindrical part and the expanded diameter part along the axial direction of the housing body is set to L2, and the clearance between the ignition part and the cylindrical part is set to C.

[0035] In the gas generator based on the present invention described above, it is preferable that the clearance is 1.0 mm or less.

[0036] In the gas generator based on the present invention described above, the portion of the helical spring that surrounds the ignition part may also be in contact with the ignition part.

[0037] Invention Effects

[0038] According to the present invention, a gas generator can be manufactured that achieves cost reduction and weight reduction. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the cylindrical gas generator according to Embodiment 1.

[0040] Figure 2 yes Figure 1 An enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator shown.

[0041] Figure 3 yes Figure 1 An enlarged cross-sectional view of the area near the partition of the cylindrical gas generator shown.

[0042] Figure 4 It means Figure 1 A cross-sectional view showing the assembly sequence of the retainer assembly in the cylindrical gas generator.

[0043] Figure 5 It means Figure 1 A cross-sectional view showing the assembly sequence of the retainer assembly in the cylindrical gas generator.

[0044] Figure 6 This is a cross-sectional view of the retainer assembly of the cylindrical gas generator involved in the first to fourth variations.

[0045] Figure 7 This is a schematic diagram of the cylindrical gas generator involved in Embodiment 2.

[0046] Figure 8 yes Figure 7 An enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator shown.

[0047] Figure 9 yes Figure 7 An enlarged cross-sectional view of the area near the partition of the cylindrical gas generator shown.

[0048] Figure 10 This is a diagram used to illustrate the preferred clearance range in the cylindrical gas generator according to Embodiment 2.

[0049] Figure 11 This is an enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator according to Embodiment 3.

[0050] Figure 12 This is an enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator according to Embodiment 4.

[0051] Figure 13 This is an enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator according to Embodiment 5.

[0052] Figure 14 This is a table that shows the test conditions and results of the verification test. Detailed Implementation

[0053] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments shown below illustrate the application of the present invention to a cylindrical gas generator installed in a side airbag device. Furthermore, in the embodiments shown below, the same or common parts are given the same reference numerals in the drawings, and their descriptions will not be repeated.

[0054] (Implementation Method 1)

[0055] Figure 1 This is a schematic diagram of the cylindrical gas generator according to Embodiment 1. Figure 2 and Figure 3 They are Figure 1 The enlarged sectional view near the igniter and the enlarged sectional view near the partition component of the cylindrical gas generator shown. First, refer to these... Figures 1 to 3 The structure of the cylindrical gas generator 1 according to this embodiment will be described.

[0056] like Figure 1 As shown, the cylindrical gas generator 1 according to this embodiment has an elongated cylindrical shape and an elongated cylindrical housing with one end and the other end blocked in the axial direction. The housing includes a housing body 10, a retainer assembly 20, and a blocking component 30.

[0057] Inside the housing, which consists of the housing body 10, the retainer assembly 20, and the blocking component 30, are housed an igniter 40, a partition component 50, a gas generator 60, a coil spring 70, and a filter 80, which are internal components. Furthermore, a combustion chamber S1, which mainly houses the gas generator 60, and a filter chamber S2, which houses the filter 80, are located inside the housing.

[0058] The housing body 10 forms the peripheral wall portion of the housing and is composed of an elongated cylindrical component with openings at both ends in the axial direction. The retainer assembly 20 is composed of a cylindrical component, having a retainer portion 20A and a connector portion 20B (described later). The cylindrical component has a hollow, through-hole-like opening extending in a direction parallel to the axial direction of the housing body 10. The closure component 30 has a cup-shaped shape including a closure portion 31 and a sidewall portion 32, and the peripheral surface of the sidewall portion 32 has an annular recess 33 for seam fixing (described later). This annular recess 33 for seam fixing is formed on the peripheral surface of the sidewall portion 32 in a manner extending circumferentially.

[0059] The shell body 10 can be constructed from metal components such as stainless steel, steel, aluminum alloy, or stainless steel alloy, or it can be constructed from a pressure-formed product that is formed into a cylindrical shape by pressure processing rolled steel sheet, represented by SPCE. Alternatively, the shell body 10 can also be constructed from an electric welded pipe, represented by STKM.

[0060] In particular, when the shell body 10 is made of a pressure-formed rolled steel plate or an electric welded pipe, the shell body 10 can be formed cheaper and easier than when using parts made of metals such as stainless steel or steel, and a significant reduction in weight can be achieved.

[0061] On the other hand, the retainer part 20A and the blocking part 300 in the retainer assembly 20 are made of metal components such as stainless steel, steel, aluminum alloy, and stainless steel alloy.

[0062] The retainer assembly 20 is fixed to the housing body 10 in such a way that it closes one of the open ends of the housing body 10 in the axial direction. Specifically, with the retainer assembly 20 inserted into the aforementioned open end of the housing body 10, the housing body 10 is radially reduced inward at a predetermined position toward the outer peripheral surface of the retainer assembly 20, thereby fixing the retainer assembly 20 relative to the housing body 10 with a converging groove. Thus, one axial end of the housing is formed by the retainer assembly 20. Further details regarding this converging groove fixing will be explained later.

[0063] The blocking member 30 is fixed to the housing body 10 in such a way that it closes the other open end of the housing body 10 in the axial direction. Specifically, with the blocking member 30 inserted into the other open end of the housing body 10, the portion of the housing body 10 corresponding to the annular recess 33 provided on the circumferential surface of the side wall portion 32 of the blocking member 30 is radially reduced inward and engages with the annular recess 33, thereby fixing the blocking member 30 relative to the housing body 10. Thus, the other end of the housing in the axial direction is formed by the blocking member 30.

[0064] These slit fixations are octagonal slit fixations that cause the housing body 10 to reduce its diameter approximately evenly toward the radially inward side. By performing this octagonal slit fixation, slit portions 12 and 13 are provided in the housing body 10. As a result, slit portions 12 and 13 directly contact the outer peripheral surface of the retainer assembly 20 and the annular recess 33, respectively, preventing gaps from forming between them.

[0065] Furthermore, the assembly structure of the closure component 30 relative to the housing body 10 is not limited to the assembly structure described above, and other assembly structures may also be adopted. In addition, the housing body 10 and the closure component 30 may not be separated into separate parts, but may be constituted by a single component having a bottomed cylindrical shape.

[0066] like Figure 1 and Figure 2 As shown, the igniter 40 is assembled to one end of the housing along its axial direction by being supported by the retainer assembly 20. The igniter 40 is a component for igniting the gas generator 60 and is arranged in a manner facing the interior space of the housing.

[0067] The igniter 40 is a component used to generate a flame and is also called a squib. The igniter 40 includes a base 41, an ignition part 42, and a pair of terminal pins 43. The base 41 is the part that holds the ignition part 42 and the pair of terminal pins 43, and is also the part that is fixed relative to the retainer assembly 20. The base 41 is held in place by inserting the pair of terminal pins 43 through the base 41.

[0068] The ignition unit 42 includes, inside which, an ignition charge that produces a flame by being ignited and burned during operation, and a resistive element (bridge wire) for igniting the ignition charge. A pair of terminal pins 43 are connected to the ignition unit 42 to ignite the ignition charge.

[0069] More specifically, the ignition section 42 includes a cup-shaped detonator cup, which has a structure in which the aforementioned resistive element is mounted by connecting the front ends of a pair of terminal pins 43 inserted into the detonator cup, and ignition powder is filled into the detonator cup in a manner that surrounds or is close to the resistive element. Furthermore, ignition powder may also be filled into the ignition section 42 as needed.

[0070] Here, as the resistive element, nickel-chromium heat-resistant alloy wire or resistance wire made of an alloy containing platinum and tungsten are generally used. As the ignition source, ZPP (zirconium-potassium perchlorate), ZWPP (zirconium-tungsten-potassium perchlorate), and lead trinitroresorcinol are generally used. In addition, as the igniter, compositions consisting of metal powders / oxidants represented by B / KNO3, B / NaNO3, and Sr(NO3)2, compositions consisting of titanium hydride / potassium perchlorate, and compositions consisting of B / 5-aminotetrazole / potassium nitrate / molybdenum trioxide are used.

[0071] When a collision is detected, a predetermined amount of current flows through the resistive element via terminal pin 43. This flow of current generates Joule heating within the resistive element, initiating combustion of the ignition charge. The high-temperature heat particles generated by combustion cause the detonator cup containing the ignition charge to crack. The time from the flow of current in the resistive element to the activation of the igniter 40 is typically less than 2 milliseconds, when a nickel-chromium heat-resistant alloy wire is used in the resistive element.

[0072] The igniter 40 is fixed to the retainer assembly 20 with its ignition part 42 protruding towards the interior of the housing and a portion thereof disposed inside the aforementioned hollow opening of the retainer assembly 20. Thus, the ignition part 42 of the igniter 40 is located on the combustion chamber S1 side, and its terminal pin 43 is located on the opposite side to the combustion chamber S1 side. Further details regarding the fixing structure of the igniter 40 relative to the retainer assembly 20 will be described later.

[0073] like Figure 1 and Figure 3 As shown, a partition member 50 is disposed at a predetermined position within the interior space of the housing. The partition member 50 is a component used to axially divide the interior space of the housing into a combustion chamber S1 and a filter chamber S2.

[0074] The separator 50 has a bottomed cylindrical shape and is made of metals such as stainless steel, steel, aluminum alloy, or stainless steel alloy. The separator 50 has a flat partition wall 51 arranged orthogonally to the axial direction of the housing body 10, and a cylindrical annular wall 52 extending from the periphery of the partition wall 51. The separator 50 is arranged such that the outer surface of its partition wall 51 abuts against the filter 80, and the outer peripheral surface of the annular wall 52 abuts against the inner peripheral surface of the housing body 10.

[0075] A score 51a is provided on the main surface of the partition wall 51 that abuts against the filter 80. The score 51a is a structure designed to cause the partition wall 51 to break and form an opening as the internal pressure of the combustion chamber S1 rises due to the combustion of the gas generator 60. For example, it is composed of multiple grooves arranged radially and intersecting each other. The score 51a is provided on the portion opposite to the hollow portion 81 in the filter 80.

[0076] The partition member 50 is secured by engaging with the housing body 10 while it is inserted into the housing body 10. More specifically, the partition member 50 is secured by being pressed into the interior of the housing body 10 and by welding at or near the contact portion where the annular wall portion 52 of the partition member 50 contacts the housing body 10.

[0077] Therefore, a welded portion 90 extending circumferentially along the housing body 10 is formed in the housing body 10 and the housing body 50 corresponding to the portion in which the partition member 50 is inserted. In addition, electron beam welding, laser welding, resistance welding, etc. can preferably be used in the welding of the partition member 50 and the housing body 10.

[0078] When the partition members 50 are fixed to the housing body 10 by welding, the gap between these partition members 50 and the housing body 10 is filled by the welded portion 90, thereby sealing the gap. Therefore, with this configuration, airtightness at this part can be ensured.

[0079] Furthermore, the method of fixing the partition member 50 to the housing body 10 is not limited to the pressing and welding methods described above; other fixing methods may also be used. In addition, ensuring the airtightness between the partition member 50 and the housing body 10 in this case can be achieved by placing O-rings, sealing strips, etc., in appropriate positions.

[0080] like Figures 1 to 3 As shown, a gas generator 60 and a helical spring 70 are disposed in the space (i.e., combustion chamber S1) sandwiched between the retainer assembly 20 and the partition member 50 inside the housing.

[0081] The gas generator 60 is a substance that generates gas by being ignited by hot particles produced by the operation of the igniter 40. As the gas generator 60, a non-azide gas generator is preferred, and the gas generator 60 is generally configured as a shaped body containing fuel, oxidant and additives.

[0082] As a fuel, it utilizes, for example, triazole derivatives, tetraazole derivatives, guanidine derivatives, azodicarbonamide derivatives, hydrazine derivatives, or combinations thereof. Specifically, it preferably utilizes, for example, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, etc.

[0083] As oxidizing agents, 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 are used. As nitrates, sodium nitrate and potassium nitrate are preferred.

[0084] Examples of additives include binders, slag-forming agents, and combustion modifiers. For example, organic binders such as metal salts of carboxymethyl cellulose and stearates can be preferably used, while inorganic binders such as hydrotalcite and acid clay can be synthesized. For slag-forming agents, silicon nitride, silica, and acid clay can be preferably used. For combustion modifiers, metal oxides, ferrosilicon, activated carbon, and graphite can be preferably used.

[0085] The gas generator 60 can be shaped into various forms, including granular, pellet-shaped, cylindrical, and disc-shaped shapes. Furthermore, cylindrical shapes can also be perforated (e.g., single-hole cylinder, multi-hole cylinder, etc.) with through-holes inside. These shapes are preferably selected appropriately based on the specifications of the gasbag device into which the cylindrical gas generator 1 is installed; for example, shapes that allow the gas generation rate to change over time during combustion of the gas generator 60 are preferred, and are the optimal shapes corresponding to the specifications. Moreover, it is preferable to appropriately select the size and filling amount of the formed body, taking into account not only the shape of the gas generator 60 but also factors such as the linear combustion rate and pressure index of the gas generator 60.

[0086] The helical spring 70 is a component designed to prevent the gas generator 60, which is made of a molded body, from being crushed due to vibration or other reasons. It has a spring portion 71 formed by bending metal wire and a pressing portion 72. The spring portion 71 is arranged such that one end abuts against the retainer assembly 20 and / or the igniter 40, and the pressing portion 72 is formed at the other end. The pressing portion 72 is constructed, for example, by arranging metal wires at predetermined intervals in a substantially parallel manner, and abuts against the gas generator 60.

[0087] Thus, the gas generator 60 is elastically forced towards the separating component 50 by the helical spring 70, preventing it from moving inside the housing.

[0088] Here, the end of the retainer assembly 20 of the coil spring 70 surrounds the ignition part 42 of the igniter 40 either in contact with it or in a manner close to it with a predetermined clearance. With this configuration, when the igniter 40 is in operation, the opening of the detonator cup of the ignition part 42 is restricted by the coil spring 70 in the event of a crack.

[0089] Therefore, by appropriately limiting the opening state of the detonator cup, the direction of travel of the thermal particles generated in the ignition section 42 is concentrated in the axial direction of the housing body 10, enabling the thermal particles to be efficiently guided to the gas generator 60. That is, the portion of the helical spring 70 that surrounds the ignition section 42 also has the function of directing the direction of travel of the thermal particles generated in the ignition section 42.

[0090] Furthermore, the structure and arrangement of the helical spring 70 in the cylindrical gas generator 1 according to this embodiment are basically the same as those of the helical spring 170 in the cylindrical gas generator 1E according to Embodiment 2 described later. In Embodiment 2, the structure, arrangement, and effects obtained by providing the helical spring 170 in the cylindrical gas generator 1E will be described in more detail. Therefore, for a deeper understanding of the helical spring 70 in the cylindrical gas generator 1 according to this embodiment, please refer to Embodiment 2 described later.

[0091] like Figure 1 As shown, a filter 80 is disposed in the space (i.e., filter chamber S2) between the blocking component 30 and the partition component 50 inside the housing. The filter 80 is composed of a cylindrical component having a hollow portion 81 extending in a direction parallel to the axial direction of the housing body 10. One end face of the filter 80 abuts against the side wall portion 32 of the blocking component 30, and the other end face of the filter 80 abuts against the partition wall portion 51 of the partition component 50.

[0092] When gas generated by the combustion of the gas generator 60 passes through the filter 80, it functions as a cooling mechanism to cool the gas by removing its high temperature, and also as a removal mechanism to remove slag (residue) and other contaminants contained in the gas. By utilizing the filter 80, which is composed of cylindrical components as described above, the flow resistance of the gas flowing in the filter chamber S2 during operation is suppressed to a low level, enabling efficient gas flow.

[0093] As the filter 80, a structure made of an assembly of metal wires or metal meshes made of stainless steel, steel, or the like can be preferably used. Specifically, an assembly of knitted metal meshes, plain-woven metal meshes, rolled metal wires, or structures that are pressed together by pressure can be used.

[0094] Furthermore, as the filter 80, a structure formed by winding a perforated metal plate can also be used. In this case, the perforated metal plate can be, for example, expanded metal that is processed into a mesh shape by setting slits in an interlaced pattern on the metal plate and expanding it to form holes, or hook metal that is flattened by perforating the metal plate and flattening the burrs generated at the periphery of the holes.

[0095] In the designated filter chamber S2 portion of the housing body 10, a plurality of gas outlets 11 are provided along the circumferential and axial directions. These plurality of gas outlets 11 are structures used to exhaust the gas that has passed through the filter 80 to the outside of the housing.

[0096] Next, refer to Figure 1 The operation of the cylindrical gas generator 1 according to this embodiment will be explained.

[0097] Reference Figure 1 In the event of a collision involving a vehicle equipped with the cylindrical gas generator 1 described in this embodiment, a collision detection mechanism separately installed in the vehicle detects the collision, and based on this, the igniter 40 operates by energizing a control unit separately installed in the vehicle.

[0098] If the igniter 40 is working, the pressure inside the ignition section 42 increases due to the combustion of the igniter or the combustion of other propellants. As a result, the detonator cup of the ignition section 42 cracks, and the hot particles generated by the combustion of the igniter or the combustion of other propellants flow out to the outside of the ignition section 42.

[0099] The hot particles flowing out from the ignition section 42 are directed by the aforementioned helical spring 70, thereby reaching the gas generating agent 60 contained in the combustion chamber S1. The hot particles that reach the gas generating agent 60 ignite, thereby generating a large amount of gas in the combustion chamber S1.

[0100] As a result, the pressure and temperature of the combustion chamber S1 rise, and the internal pressure of the combustion chamber S1 reaches a predetermined pressure, causing the portion of the partition member 50 with the notch 51a to break. Consequently, an opening (communication hole) is formed in the partition member 50 at the portion opposite to the hollow portion 81 of the filter 80, so that the combustion chamber S1 and the filter chamber S2 are connected through the opening.

[0101] Subsequently, the gas generated in the combustion chamber S1 flows into the filter chamber S2 through the opening formed in the partition member 50. After flowing axially in the hollow portion 81 of the filter 80, the gas flowing into the filter chamber S2 changes direction radially and flows inside the filter 80. At this time, heat is taken away by the filter 80 and the gas is cooled, and the residue contained in the gas is removed by the filter 80.

[0102] Then, the gas flowing through the filter 80 is ejected to the outside of the housing via the gas outlet 11 provided in the housing body 10. The ejected gas is introduced into the interior of the air bladder provided adjacent to the cylindrical gas generator 1, inflating and deploying the air bladder.

[0103] Here, as described above, the cylindrical gas generator 1 according to this embodiment has a retainer assembly 20 as part of the housing, which is mounted on the opening end of the housing body 10 at one end side as described above. Hereinafter, referring to... Figure 2 The structure of the retainer assembly 20, the fixing structure of the igniter 40 relative to the retainer assembly 20, and the fixing structure of the retainer assembly 20 relative to the housing body 10 will be described in detail.

[0104] like Figure 2 As shown, the retainer assembly 20 has a metal retainer portion 20A located on the combustion chamber S1 side and a resin connector portion 20B located on the opposite side of the combustion chamber S1 side. The retainer assembly 20 is configured as a part that is integrated by pre-assembling these retainer portions 20A and connector portions 20B together, and is installed at the opening on one end side of the housing body 10 as described above.

[0105] The retainer part 20A is composed of a flat, generally disc-shaped component having a through portion extending axially in its central part, including a cylindrical first body part 21 and an annular protrusion 22 protruding outward from the outer peripheral surface of the first body part 21.

[0106] The retainer portion 20A is inserted into the housing body 10 with its axial direction parallel to the axial direction of the housing body 10. Thus, the through portion provided in the retainer portion 20A defines a portion of the aforementioned hollow opening of the retainer assembly 20. Furthermore, an annular protrusion 22 protrudes radially from the first body portion 21 along the housing body 10. Additionally, the aforementioned annular protrusion 22 is provided at the end of the first body portion 21 on the combustion chamber S1 side.

[0107] The retainer section 20A defines the combustion chamber S1 located inside the housing body 10 and functions as a pressure partition. Therefore, the retainer section 20A is made of metal as described above, and has high strength to withstand the pressure rise in the combustion chamber S1 during the operation of the cylindrical gas generator 1.

[0108] Furthermore, the retainer portion 20A is also a component used to receive and hold the igniter 40. To receive the retainer portion 20A, a concave receiving portion 23a is provided at its axial combustion chamber S1 side end. This receiving portion 23a communicates with the through portion provided in the retainer portion 20A. Additionally, a converging portion 23b is provided at the combustion chamber S1 side end of the retainer portion 20A to surround the receiving portion 23a. The converging portion 23b is used to secure the igniter 40 to the retainer portion 20A.

[0109] The igniter 40 is fixed to the retainer portion 20A with its base 41 housed in the receiving portion 23a. Specifically, the base 41 is inserted into the receiving portion 23a of the retainer portion 20A and stops against the bottom surface of the receiving portion 23a. In this state, the concave portion 23b of the retainer portion 20A is bent, thereby fixing the igniter 40 to the retainer portion 20A. Thus, the igniter 40 is held by the retainer portion 20A.

[0110] Here, a sealing member 29, made of an O-ring or the like, is sandwiched between the retainer portion 20A and the igniter 40. This seals the gap between the retainer portion 20A and the igniter 40 by filling it with the sealing member 29. Therefore, this configuration ensures airtightness at this location. Furthermore, the method of fixing the igniter 40 is not limited to the method using the slit portion 23b described above; other fixing methods can also be used.

[0111] The connector part 20B is composed of a generally cylindrical component having a through portion extending axially in its central portion, including a cylindrical second body part 24, a cylindrical part 25 extending axially from one end of the second body part 24, and a flange part 26 provided at the other end of the second body part 24.

[0112] The connector portion 20B is partially inserted into the housing body 10 with its axial direction parallel to the axial direction of the housing body 10. More specifically, the portion of the connector portion 20B, excluding the flange portion 26, is inserted into the open end of the housing body 10, with the flange portion 26 located outside the housing body 10 and abutting against the axial end face of the housing body 10. Thus, the through portion provided in the connector portion 20B defines a portion of the aforementioned hollow opening of the retainer assembly 20, and the cylindrical portion 25 extends from the second body portion 24 toward the combustion chamber S1.

[0113] Here, the aforementioned retainer portion 20A is secured by being pressed into the connector portion 20B. More specifically, the first body portion 21 of the retainer portion 20A is pressed into the cylindrical portion 25 of the connector portion 20B, thereby securing the retainer portion 20A and the connector portion 20B by pressure contact between the first body portion 21 and the cylindrical portion 25 so that they cannot easily detach.

[0114] The connector section 20B is a component used to receive a connector that connects to the terminal pin 43 of the igniter 40. The terminal pin 43 of the igniter 40 is disposed inside the connector section 20B. A through-hole provided in the connector section 20B constitutes a portion for receiving the connector.

[0115] More specifically, in the cylindrical gas generator 1, the igniter 40 needs to be electrically connected to a control unit (not shown) located externally, such as in a vehicle, and this electrical connection typically uses electrical wiring. A male connector is installed at the front end of this electrical wiring, and a female connector that can connect to the male connector is required at the connector section 20B. The aforementioned through-hole provided in the connector section 20B constitutes the female connector.

[0116] In addition, the male connector of the electrical wiring is inserted into the through part that functions as a female connector, thereby achieving electrical conduction between the core wire of the electrical wiring and the terminal pin 43, and thus connecting the igniter 40 to the control unit of the vehicle, etc.

[0117] Furthermore, the connector portion 20B also functions as a component to ensure the airtightness between the housing body 10 and the retainer portion 20A. The portion used to ensure the airtightness between the housing body 10 and the retainer portion 20A is mainly the cylindrical portion 25 in the connector portion 20B.

[0118] Specifically, the cylindrical portion 25 is inserted into the open end of the housing body 10 and externally inserted into the first body portion 21 of the retainer portion 20A. Thus, the portion in the axial direction of the housing body 10 where the cylindrical portion 25 is located is arranged radially outward from the radially inner side of the housing body 10, with the first body portion 21 of the retainer portion 20A, the cylindrical portion 25 of the connector portion 20B, and the housing body 10 arranged in that order. That is, the first body portion 21 is surrounded by the cylindrical portion 25, and the cylindrical portion 25 is surrounded by the housing body 10.

[0119] Furthermore, a converging slit 12 is provided in the housing body 10 corresponding to the cylindrical portion 25 (i.e., the portion covering the cylindrical portion 25). By providing this converging slit 12, the cylindrical portion 25 of the connector portion 20B, which is made of resin, is sandwiched between the converging slit 12 of the housing body 10, which is made of metal, and the first body portion 21 of the retainer portion 20A, which is made of metal, thereby sealing the gap between the housing body 10 and the first body portion 21 by the cylindrical portion 25.

[0120] Here, when the constricted slit 12 is provided in the shell body 10, the cylindrical portion 25 is sandwiched between the shell body 10 and the first body portion 21, and is subjected to their load, causing the cylindrical portion 25 to undergo compression deformation. As a result, the cylindrical portion 25 is in close contact with the shell body 10, and the cylindrical portion 25 is in close contact with the first body portion 21.

[0121] Therefore, the cylindrical portion 25 is sandwiched between the housing body 10 and the first body portion 21 in a state of close contact with each other, thus achieving the sealing of the aforementioned gap. Consequently, with this configuration, airtightness at this location can be ensured.

[0122] The material of the connector part 20B is not particularly limited, but it is preferable to use nylon resins such as nylon 6, nylon 66 and materials filled with glass filler, polyacetal (POM) resin, polycarbonate (PC) resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, etc.

[0123] Furthermore, in the retainer section 20A, an annular protrusion 22 is provided at a position closer to the combustion chamber S1 than the first body section 21. Therefore, the annular protrusion 22 also functions as a stop to prevent the retainer assembly 20 from detaching from the housing body 10. This function of the annular protrusion 22 as a stop is performed not only during the manufacturing of the cylindrical gas generator 1 and when it is not in operation, but also during operation when it is subjected to pressure that accompanies the increase in internal pressure of the combustion chamber S1.

[0124] Here, in the cylindrical gas generator 1 according to this embodiment, the inner diameter r1 of the cylindrical portion 25 is larger than the inner diameter r2 of the second body portion 24, and an annular stepped surface 27 connecting the inner circumferential surface 24a of the second body portion 24 and the inner circumferential surface 25a of the cylindrical portion 25 is provided in the connector portion 20B. As a result, a first chamber 28a defined by the annular stepped surface 27 and the inner circumferential surface 25a of the cylindrical portion 25 is provided at the axial end of the connector portion 20B located on the combustion chamber S1 side.

[0125] The first body part 21 of the retainer part 20A is inserted into the first chamber 28a. Furthermore, the axial end face 21a of the first body part 21 located on the opposite side of the combustion chamber S1 abuts against the annular step surface 27.

[0126] With this configuration, the retainer portion 20A and the connector portion 20B can be fixed by pressing the retainer portion 20A into the connector portion 20B as described above, and the retainer portion 20A and the connector portion 20B can be positioned with good axial accuracy along the housing body 10.

[0127] Furthermore, in the cylindrical gas generator 1 according to this embodiment, the inner diameter r2 of the second body portion 24 is larger than the inner diameter r3 of the first body portion 21. Therefore, at the axial end of the retainer assembly 20 located on the side opposite to the combustion chamber S1, a second chamber 28b is provided, defined by the axial end face 21a of the first body portion 21 located on the side opposite to the combustion chamber S1 and the inner circumferential surface 24a of the second body portion 24.

[0128] The second chamber 28b corresponds to the through portion provided in the connector section 20B, and constitutes the female connector that should be provided in the connector section 20B.

[0129] With this configuration, the aforementioned female connector, which should be provided in the connector section 20B, can be easily provided in the connector section 20B, and the structure of the retainer assembly 20 can be simplified.

[0130] Figure 4 and Figure 5 It means Figure 1 A cross-sectional view showing the assembly sequence of the retainer assembly in the cylindrical gas generator. Next, refer to these... Figure 4 and Figure 5 The assembly sequence of the retainer assembly 20 in the cylindrical gas generator 1 according to this embodiment will be explained.

[0131] When assembling the retainer assembly 20 into the housing body 10, firstly, as follows: Figure 4As shown, an assembly in which the igniter 40 is assembled is prepared in the retainer section 20A and assembled relative to the connector section 20B. Specifically, the retainer section 20A with the igniter 40 assembled is assembled relative to the connector section 20B by pressing the first body section 21 of the retainer section 20A into the cylindrical section 25 of the connector section 20B.

[0132] Next, the housing body 10 is inserted relative to the retainer assembly 20, to which the retainer part 20A is assembled in the connector part 20B. At this time, the open end of the housing body 10 is inserted to cover the second body part of the connector part 20B, and the axial end face of the housing body 10 abuts against the flange part 26 of the connector part 20B.

[0133] Alternatively, the retainer portion 20A can be pressed into the housing body 10 at this time. That is, the housing body 10 can be inserted externally relative to the retainer assembly 20 so that the circumferential surface of the annular protrusion 22 of the retainer portion 20A makes pressure contact with the inner main surface of the housing body 10. With this configuration, the housing body 10 and the retainer assembly 20 are temporarily fixed by this pressing, making subsequent handling easier.

[0134] Next, as Figure 5 As shown, a slit-cutting process is performed to reduce the diameter of the housing body 10 at a predetermined position. More specifically, a slit-cutting portion 12 is provided in the housing body 10 by reducing the diameter of the portion of the housing body 10 corresponding to the cylindrical portion 25 of the connector portion 20B toward the radially inward side of the housing body 10 (i.e., toward the direction of arrow A in the figure).

[0135] Thus, the cylindrical portion 25 of the connector portion 20B is clamped into the constricted portion 12 of the housing body 10 and the first body portion 21 of the retainer portion 20A, and the gap between the housing body 10 and the first body portion 21 is sealed by the cylindrical portion 25.

[0136] After going through the above series of processes, the retainer assembly 20 is assembled relative to the housing body 10, and the opening end of the housing body 10 at one end is closed by the retainer assembly 20.

[0137] By constructing the cylindrical gas generator according to the embodiment described above, the gap between the housing body 10 and the retainer assembly 20 can be sealed by the cylindrical portion 25 of the resin connector portion 20B, a part of the retainer assembly 20. Therefore, sealing components such as O-rings made of other parts are no longer required for sealing this portion, thus reducing component costs and greatly simplifying the assembly process.

[0138] Furthermore, by constructing a retainer assembly 20 that is a composite part of a metal retainer portion 20A and a resin connector portion 20B, which was previously a single metal component, the amount of metal material used can be drastically reduced, resulting in significant weight reduction. In addition, the high machining precision required when constructing a retainer with a single metal component is no longer necessary, thus greatly simplifying the retainer's structure. Therefore, material costs and processing costs can also be reduced in this respect.

[0139] Therefore, by using the cylindrical gas generator 1 described in the cost-effective implementation method, manufacturing costs are reduced and weight is reduced compared to the past.

[0140] (Variations 1 to 4)

[0141] Figure 6 This is a cross-sectional view of the retainer assembly of the cylindrical gas generator according to the first to fourth modifications of Embodiment 1 described above. Hereinafter, referring to this... Figure 6 The retainer assembly 20 of the cylindrical gas generators 1A to 1D involved in the first to fourth modified examples will be described.

[0142] Figure 6 The retainer assembly 20 of the cylindrical gas generator 1A shown in (A) differs from the embodiment 1 described above only in the shape of the first body portion 21 of the retainer portion 20A.

[0143] Specifically, in the retainer assembly 20 according to the first modification, the outer peripheral surface 21b of the first body portion 21 has an inclined shape that narrows as it moves toward the combustion chamber S1 side (i.e., the side opposite to the connector portion 20B side). Therefore, in the state before the retainer assembly 20 is assembled to the housing body 10, a gap is generated between the cylindrical portion 25 of the connector portion 20B and the first body portion 21 of the retainer portion 20A.

[0144] In this configuration, when the converging slit 12 is provided in the housing body 10, the cylindrical portion 25 of the connector portion 20B is compressed and deformed under load while tilting towards the radially inward side of the housing body 10. At this time, the load applied by the converging slit 12 provided in the housing body 10 to the first body portion 21 of the retainer portion 20A acts towards the side where the terminal pin 43 of the igniter 40 is located.

[0145] Therefore, with this structure, the seam 12 acts more firmly on the retainer portion 20A, and in addition to the effects described in Embodiment 1 above, it is possible to more reliably prevent the retainer assembly 20 from falling off the housing body 10.

[0146] Figure 6 (B) to Figure 6 The retainer assembly 20 of the cylindrical gas generators 1B to 1D involved in the second to fourth modifications shown in (D) differs from the embodiment 1 described above only in the shape of the cylindrical portion 25 of the connector portion 20B.

[0147] Specifically, in the retainer assembly 20 involved in the second to fourth modifications, a concave portion is pre-formed on the outer peripheral surface of the cylindrical portion 25 at a position corresponding to the slit portion 12 provided on the housing body 10.

[0148] Here, in Figure 6 In the retainer assembly 20 involved in the second modified example shown in (B), the concave portion is configured such that it has a C-shaped cross-section; Figure 6 In the retainer assembly 20 of the third modified example shown in (C), the thin-walled portion formed in the cylindrical portion 25 by providing the concave portion extends from the position corresponding to the converging portion 12 provided in the housing body 10 toward the combustion chamber S1 side (i.e., the side opposite to the flange portion 26 side of the connector portion 20B); Figure 6 In the retainer assembly 20 of the fourth modified example shown in (D), the thin-walled portion formed in the cylindrical portion 25 by providing the concave part extends from the position corresponding to the slit portion 12 provided in the housing body 10 toward the side opposite to the combustion chamber S1 side (i.e., the flange portion 26 side of the connector portion 20B).

[0149] With this configuration, when the converging portion 12 is provided in the housing body 10, the tightness of the converging portion 12 of the housing body 10 and the cylindrical portion 25 of the connector portion 20B becomes higher.

[0150] Therefore, when this structure is adopted, in addition to the effects described in Embodiment 1 above, the sealing performance between the housing body 10 and the first body part 21 can also be improved.

[0151] (Implementation Method 2)

[0152] Figure 7 This is a schematic diagram of the cylindrical gas generator involved in Embodiment 2. Figure 8 and Figure 9 They are Figure 7 The enlarged sectional view near the igniter and the enlarged sectional view near the partition component of the cylindrical gas generator shown. First, refer to these... Figures 7 to 9 The structure of the cylindrical gas generator 1E involved in this embodiment will be described.

[0153] like Figure 7As shown, the cylindrical gas generator 1E according to this embodiment has a structure similar to that of the cylindrical gas generator 1 according to Embodiment 1 above. It includes a housing body 110, a retainer 120 and a blocking member 130 as housings, and an igniter 140, a partition member 150, a gas generating agent 160, a coil spring 170, a filter 180 and other internal components housed inside the housing.

[0154] The housing body 110 forms the peripheral wall of the housing and is composed of an elongated cylindrical component with openings at both ends in the axial direction. The retainer 120 is composed of a cylindrical component having a through portion 121 extending in the same direction as the axial direction of the housing body 110, and has an annular groove 122 for closure and fixing (described later) on its outer peripheral surface. The closure component 130 is composed of a disc-shaped component with a predetermined thickness, and has an annular groove 131 for closure and fixing (described later) on its peripheral surface. These annular grooves 122 and 131 for closure and fixing are formed on the outer peripheral surface of the retainer 120 and the peripheral surface of the closure component 130 in a circumferentially extending manner.

[0155] The materials of the housing body 110 and the blocking component 130 can be the same as those of the housing body 10 and the blocking component 30 in Embodiment 1 above, and the material of the retainer 120 can be the same as that of the retainer portion 20A in the retainer assembly 20 in Embodiment 1 above.

[0156] The retainer 120 is fixed to the housing body 110 in such a way that it closes one of the axial open ends of the housing body 110. Specifically, with the retainer 120 inserted into the aforementioned one open end of the housing body 110, the portion of the housing body 110 corresponding to the annular groove 122 provided on the outer peripheral surface of the retainer 120 is radially reduced in diameter and engages with the annular groove 122, thereby fixing the retainer 120 relative to the housing body 110. Thus, one axial end of the housing is formed by the retainer 120.

[0157] The blocking member 130 is fixed to the housing body 110 in such a way that it closes the other open end of the housing body 110 in the axial direction. Specifically, with the blocking member 130 inserted into the other open end of the housing body 110, the portion of the housing body 110 corresponding to the annular groove 131 provided on the circumferential surface of the blocking member 130 is radially reduced inward and engaged with the annular groove 131, thereby fixing the blocking member 130 relative to the housing body 110. Thus, the other axial end of the housing is formed by the blocking member 130.

[0158] These slits can be fixed as octagonal slits as described in Embodiment 1 above. By performing this octagonal slit, slit portions 112 and 113 are provided on the housing body 110. As a result, slit portions 112 and 113 directly contact the annular groove portions 122 and 131, respectively, preventing gaps from forming between them.

[0159] Furthermore, the assembly structure of the retainer 120 and the closure component 130 relative to the housing body 110 is not limited to the assembly structure described above, and other assembly structures may also be adopted. In addition, the housing body 110 and the closure component 130 may not be made into separate parts, but may be constituted by a single component having a bottomed cylindrical shape.

[0160] like Figure 7 and Figure 8 As shown, the igniter 140 is assembled to one end of the housing along its axial direction by means of a retainer 120. The igniter 140 is a component for igniting the gas generator 160 and is arranged in a manner facing the interior space of the housing.

[0161] The igniter 140 includes an ignition section 141 and a pair of terminal pins 142. The ignition section 141 includes an ignition powder 141a, a plug 141b, and a cup 141c (equivalent to the detonator cup described in Embodiment 1 above). The ignition powder 141a is housed within the ignition section 141 by being disposed within the space defined by the plug 141b and the cup 141c. Furthermore, a resistor (a standard bridge wire) is installed inside the ignition section 141 in a manner connected to the pair of terminal pins 142, and the ignition powder 141a is filled within the ignition section 141 in a manner that surrounds or contacts the resistor. Additionally, a detonator may also be loaded into the ignition section 141 as needed.

[0162] Here, the same materials as those used in the embodiments described above can be used as the resistive element, igniter, and igniter. Furthermore, the cup 141c provided in the ignition section 141 includes a metal cup.

[0163] The igniter 140 is fixed to the retainer 120 by means of a slit 123 provided in the retainer 120. More specifically, the retainer 120 has a slit 123 at its axial end facing the interior space of the housing for fixing the igniter 140. The slit 123 is slit when the igniter 140 is inserted into the through portion 121 and abuts against a portion of the wall of the retainer 120 and is stopped, thereby clamping and fixing the igniter 140 in the retainer 120.

[0164] Thus, the igniter 140 is assembled into the retainer 120 with its ignition part 141 protruding toward the interior of the housing. Therefore, when the igniter 140 is in operation, the ignition powder 141a is ignited, causing the cup 141c to crack, and the cup 141c opens as a result of this cracking.

[0165] A sealing member 125, made of an O-ring or the like, is sandwiched between the retainer 120 and the igniter 140, thereby filling the gap between them and sealing it. Thus, this configuration ensures airtightness at this location. Furthermore, the method of securing the igniter 140 is not limited to the method using the concave portion 123 described above; other securing methods can also be used.

[0166] At the axial end of the retainer 120 that is exposed to the outside, a recess 124 is provided, continuous with the through portion 121 described above. The recess 124 forms a female connector portion for receiving a male connector (not shown) for connecting the igniter 140 to the control unit (not shown). A portion near the front end of the terminal pin 142 of the igniter 140 is exposed and positioned within the recess 124. The male connector is inserted into the recess 124, which serves as the female connector portion, thereby achieving electrical connection between the core wire of the electrical wiring and the terminal pin 142.

[0167] like Figure 7 and Figure 9 As shown, a partition member 150 is disposed at a predetermined position within the interior space of the housing. The partition member 150 is a component used to axially divide the interior space of the housing into a combustion chamber S1 and a filter chamber S2.

[0168] The separator 150 has a generally cylindrical shape with a base, and is made of metals such as stainless steel, steel, aluminum alloy, or stainless steel alloy. The separator 150 has a flat partition wall 151 arranged orthogonally to the axial direction of the housing body 110, and a cylindrical annular wall 152 extending from the periphery of the partition wall 151. The separator 150 is arranged such that the outer surface of its partition wall 151 abuts against the filter 180, and the outer peripheral surface of the annular wall 152 abuts against the inner peripheral surface of the housing body 110.

[0169] A notch 151a is provided on the main surface of the partition wall 151 that abuts against the filter 180. The notch 151a is a structure designed to cause the partition wall 151 to break and form an opening as the internal pressure of the combustion chamber S1 rises due to the combustion of the gas generator 160. For example, it is composed of multiple grooves arranged radially and intersecting each other. The notch 151a is provided in the portion of the filter 180 opposite to the hollow portion 181.

[0170] An annular groove extending circumferentially is provided at the periphery of the partition wall portion 151, which serves as the boundary with the annular wall portion 152. An O-ring 153 is accommodated in this annular groove. With this configuration, the O-ring 153 is clamped between the partition member 150 and the housing body 110, and is in pressure contact with both the partition member 150 and the housing body 110.

[0171] Therefore, the gap between the separator 150 and the housing body 110 is filled by the O-ring 153. Thus, by sealing this gap with the O-ring 153, airtightness at this part can be ensured.

[0172] The separator 150 is fixed to the housing body 110 while inserted inside it. More specifically, the separator 150 is pressed into the interior of the housing body, thereby bringing the annular wall portion 152 of the separator 150 into pressure contact with the housing body 110. Therefore, the separator 150 is fixed to the housing body 110 by means of the elastic restoring force of the annular wall portion 152.

[0173] like Figures 7 to 9 As shown, a gas generator 160 and a coil spring 170 are disposed in the space (i.e., combustion chamber S1) between the retainer 120 and the partition member 150 inside the housing.

[0174] As the gas generator 160, the same substance as the gas generator 60 in the above embodiments can be used.

[0175] like Figure 7 and Figure 8 As shown, a helical spring 170 is disposed in the space of the combustion chamber S1 on the side closer to the retainer 120 than the gas generator 160. The helical spring 170 is formed by bending metal wire and includes a cylindrical portion 171, an expanded diameter portion 172, and a pressing portion 173.

[0176] The cylindrical portion 171 is constructed by winding a metal wire into a spiral shape with a fixed inner diameter, thereby having a generally cylindrical shape as a whole. The cylindrical portion 171 is located on the retainer 120 side (i.e., the aforementioned end side of the housing), and one of its axial ends abuts against the retainer 120 and / or the igniter 140.

[0177] The expanded diameter section 172 is constructed by winding a metal wire into a spiral shape such that its inner diameter increases as it moves toward the gas generator 160 side, thereby giving it a hollow, approximately frustum-shaped form as a whole. The expanded diameter section 172 extends from the other end of the cylindrical section 171 (i.e., the end on the gas generator 160 side) toward the gas generator 160 side. The outer diameter of the gas generator 160 side end of the expanded diameter section 172 is configured to be approximately the same as or slightly smaller than the inner diameter of the housing body 110.

[0178] The pressing part 173 is located at the end of the expanding part 172 on the side of the gas generating agent 160. It is configured as a whole to have a generally circular plate shape by, for example, arranging the metal wires in a generally parallel manner at a predetermined interval, or arranging the metal wires in a spiral shape at a predetermined interval. The pressing part 173 is in contact with the gas generating agent 160.

[0179] The helical spring 170 is arranged to surround the ignition portion 141 of the igniter 140, which has a generally cylindrical shape. That is, the helical spring 170 is arranged substantially coaxially with the ignition portion 141, surrounding the ignition portion 141 without any other components sandwiched between them. Thus, the side of the ignition portion 141 is surrounded by a portion of the cylindrical portion 171 of the helical spring 170, and the space between the ignition portion 141 and the gas generating agent 160 is surrounded by the remaining portion of the cylindrical portion 171 of the helical spring 170 and the expanded diameter portion 172.

[0180] Here, the coil spring 170 is compressed by being clamped between the retainer 120 and / or the igniter 140 and the gas generator 160. Therefore, the gas generator 160 is elastically forced by the coil spring 170 toward the separating member 150 (i.e., the other end of the housing described above, opposite to the side where the retainer 120 is located), thereby preventing the gas generator 160 from moving inside the housing. Thus, with this configuration, the possibility of the gas generator 160, which is made of a molded body, being shattered due to vibration or other factors can be prevented.

[0181] Furthermore, during the assembly of the helical spring 170, the dimensional discrepancies of various constituent parts housed inside the housing can also be absorbed by the helical spring 170 as it is clamped and compressed by the retainer 120 and / or the igniter 140 and the gas generator 160.

[0182] Furthermore, by appropriately setting the axial length of the helical spring 170, the distance from the igniter 140 assembled at one end of the housing to the gas generator 160 can be properly ensured. Therefore, when the igniter 140 is in operation, the cracking of the cup 141c of the ignition part 141 is no longer hindered by the gas generator 160, so the gas generator 160 can be ignited earlier and more reliably.

[0183] In addition, in the cylindrical gas generator 1E according to this embodiment, as described above, by surrounding the ignition section 141 and the space between the ignition section 141 and the gas generating agent 160 by the coil spring 170, when the igniter 140 is in operation, the opening state of the cup 141c of the ignition section 141 is restricted by the coil spring 170 when the cup 141c of the ignition section 141 cracks. Therefore, as a result, the thermal particles generated in the ignition section 141 can be given directionality, but details of this will be described later.

[0184] like Figure 7 As shown, a filter 180 is disposed in the space (i.e., filter chamber S2) between the blocking component 130 and the separating component 150 inside the housing. The filter 180 is composed of a cylindrical component having a hollow portion 181 extending in the same direction as the axial direction of the housing body 110, one end face of which abuts against the blocking component 130, and the other end face of which abuts against the separating component 150.

[0185] The filter 180 is similar to the filter 80 in Embodiment 1 described above. It functions as a cooling mechanism for cooling the gas and as a removal mechanism for removing residues and the like contained in the gas. Its structure and material can be the same as those of the filter 80 in Embodiment 1 described above.

[0186] In the designated filter chamber S2 portion of the housing body 110, a plurality of gas outlets 111 are provided along the circumferential and axial directions. These plurality of gas outlets 111 are components used to exhaust the gas that has passed through the filter 180 to the outside of the housing.

[0187] Furthermore, the operation of the cylindrical gas generator 1E in this embodiment is basically the same as that of the cylindrical gas generator 1 in Embodiment 1 described above, so it will not be repeated here.

[0188] Here, as described above, in the cylindrical gas generator 1E according to this embodiment, as... Figure 8 As shown, a helical spring 170, clamped between one axial end of the housing (i.e., the retainer 120) and the gas generating agent 160, is arranged substantially coaxially with the ignition part 141, surrounding the ignition part 141 of the igniter 140 without any other components sandwiched between them. Furthermore, the helical spring 170 not only surrounds the ignition part 141 of the igniter 140, but also the space between the ignition part 141 and the gas generating agent 160.

[0189] With this configuration, firstly, by surrounding the cylindrical portion 171 of the coil spring 170 with the ignition part 141, it is possible to suppress cracking or outward deformation of the side wall portion of the cup 141c when the cup body 141c of the ignition part 141 cracks. Therefore, it is possible to form an opening primarily at the front end portion located on the side of the gas generator 160 within the cup body 141c.

[0190] Furthermore, secondly, when the cup 141c of the ignition unit 141 cracks and forms an opening at the front end of the cup 141c, the opened portion of the cup 141c contacts the main expansion portion 172 in the coil spring 170, which can prevent the opened portion of the cup 141c from deforming further outward. Therefore, the expansion portion 172 of the coil spring 170 and the opened portion of the cup 141c also function as guides to determine the direction of travel of the thermal particles.

[0191] Therefore, the direction of travel of the hot particles generated in the ignition section 141 is concentrated along the axial direction of the housing body 110, which can efficiently guide the hot particles toward the gas generator 160. Thus, the helical spring 170 not only functions to fix the gas generator 160 inside the housing, but also functions to efficiently guide the hot particles generated in the igniter 140 during operation toward the gas generator 160, eliminating the need for components such as the combustion control shroud that were previously required.

[0192] Thus, by using the cylindrical gas generator 1E as described in the cost-effective implementation method, the number of parts can be reduced compared to the past, thereby simplifying the assembly process and achieving weight reduction as a whole gas generator. Therefore, it is possible to achieve both weight reduction and manufacturing cost reduction while maintaining good gas output characteristics.

[0193] Furthermore, in order to efficiently guide the hot particles generated by the ignition section 141 towards the gas generator 160, it is necessary to impart a suitable directionality to the hot particles. However, the degree of directionality imparted to the hot particles is specifically determined by the clearance between the ignition section 141 and the cylindrical portion 171 of the coil spring 170 that surrounds the ignition section 141. Hereinafter, refer to... Figure 10 The preferred range for this clearance is explained. Figure 10 This is a diagram used to illustrate the preferred clearance range of the cylindrical gas generator according to this embodiment.

[0194] From the viewpoint of preventing cracking or deformation of the side wall portion of the cup body 141c, it is preferable that there is no gap between the ignition part 141 and the cylindrical part 171. However, it is not necessarily easy to press the helical spring 170 made of metal wire into the ignition part 141, and from the viewpoint of simplifying the assembly operation, it is preferable to provide the aforementioned gap slightly.

[0195] Based on the results of the verification test described later, it was confirmed that the clearance is preferably at least 1.0 mm or less. However, if the opening portion of the enlarged diameter portion 172 and the cup body 141c is also considered to function as a guide portion, its upper limit can be determined as follows.

[0196] That is, in reference Figure 10 When the inner diameter of the housing body 110 containing the space of the gas generator 160 is set to R1, the outer diameter of the ignition part 141 is set to R2, the distance from the portion of the ignition part 141 containing the igniter 141 to the gas generator 160 along the axial direction of the housing body 110 is set to L1, and the distance from the portion of the ignition part 141 containing the igniter 141 to the boundary between the cylindrical part 171 and the expanded diameter part 172 along the axial direction of the housing body 110 is set to L2, the clearance C between the ignition part 141 and the cylindrical part 171 preferably satisfies the condition 0 < C ≤ (R1 - R2) × (L2 / L1) / 2 (hereinafter referred to as the "first condition").

[0197] By satisfying the first condition described above, when viewed from the ignition section 141, the gas generating agent 160 is located within the range where hot particles are guided by the expanded diameter section 172 and the open portion of the cup body 141c, thus enabling very efficient guidance of hot particles to the gas generating agent 160. Therefore, in order to reliably obtain the above-described effect, it is preferable to satisfy this first condition.

[0198] In addition, in reference Figure 10 When the outer diameter of the ignition part 141 is set to R2, and the inherent elongation of the material of the cup 141c constituting the ignition part 141 of the ignition device 140 is set to e, the clearance C between the ignition part 141 and the cylindrical part 171 is preferably such that 0 ≤ C ≤ e × R2 / 2 (hereinafter referred to as "the second condition"). Here, the elongation e refers to the percentage value expressed as the ratio of the elongation occurring between the marks on the test piece until the test piece breaks to the distance between the marks in a tensile test using the material.

[0199] By satisfying the second condition described above, when the igniter 140 is in operation, the deformation of the cup 141c constituting the ignition part 141 comes into contact with the cylindrical part 171 before the cup 141c breaks, thereby suppressing further deformation of the cup 141c. Therefore, in order to reliably obtain the above-described effect, it is preferable to satisfy the second condition.

[0200] (Implementation Method 3)

[0201] Figure 11 This is an enlarged cross-sectional view of the vicinity of the igniter in the cylindrical gas generator according to Embodiment 3. Next, referring to this... Figure 11 The cylindrical gas generator 1F involved in this embodiment will be described.

[0202] like Figure 11 As shown, compared with the cylindrical gas generator 1E of Embodiment 2 described above, the cylindrical gas generator 1F according to this embodiment has a different inner diameter of the cylindrical portion 171 of the helical spring 170, thereby allowing the cylindrical portion 171 to contact the ignition portion 141. That is, in the cylindrical gas generator 1F according to this embodiment, there is no clearance between the ignition portion 141 and the cylindrical portion 171.

[0203] With this configuration, the effects described in Embodiment 2 above are also achieved, enabling the balance between maintaining good gas output characteristics and reducing weight and manufacturing costs. Furthermore, with this configuration, although the workability is slightly worse than with a clearance setting when the coil spring 170 needs to be pressed into the ignition part 141 during assembly, it is more reliable in preventing cracking and deformation of the side wall portion of the cup body 141c.

[0204] (Implementation Method 4)

[0205] Figure 12 This is an enlarged cross-sectional view of the vicinity of the igniter in the cylindrical gas generator according to Embodiment 4. Next, referring to this... Figure 12 The cylindrical gas generator 1G involved in this embodiment will be described.

[0206] like Figure 12 As shown, the cylindrical gas generator 1G according to this embodiment differs from the cylindrical gas generator 1F according to Embodiment 3 only in the number of turns of the metal wire in the cylindrical portion 171 of the helical spring 170. Specifically, in the cylindrical gas generator 1G, the spacing of the metal wire in the portion of the cylindrical portion 171 of the helical spring 170 that surrounds the ignition portion 141 of the igniter 140 is made narrower, and the number of turns in that portion of the cylindrical portion 171 is increased.

[0207] With this configuration, the effects described in Embodiment 3 above are also achieved, enabling the balance between maintaining good gas output characteristics and reducing weight and manufacturing costs. Furthermore, with this configuration, the deformation of the side wall portion of the cup 141c during the operation of the igniter 140 can be more reliably suppressed, corresponding to the increase in the number of turns of the metal wire in the cylindrical portion 171 of the helical spring 170.

[0208] (Implementation Method 5)

[0209] Figure 13 This is an enlarged cross-sectional view of the vicinity of the igniter in the cylindrical gas generator according to Embodiment 5. Next, referring to this... Figure 13 The cylindrical gas generator 1H according to this embodiment will be described.

[0210] like Figure 13 As shown, the cylindrical gas generator 1H according to this embodiment differs from the cylindrical gas generator 1G according to Embodiment 4 only in the structure of the cylindrical portion 171 and the expanded diameter portion 172 of the helical spring 170. Specifically, in the cylindrical gas generator 1H, compared with the cylindrical gas generator 1G, the axial length of the cylindrical portion 171 of the helical spring 170 is configured to be longer, and the axial length of the expanded diameter portion 172 of the helical spring 170 is configured to be shorter.

[0211] That is, in the cylindrical gas generator 1H according to this embodiment, only the end of the portion of the helical spring 170 adjacent to the pushing portion 173 is configured as an enlarged diameter portion 172. Thus, not only the ignition portion 141 of the igniter 140, but also most of the space between the ignition portion 141 and the gas generating agent 160 is surrounded by the cylindrical portion 171 of the helical spring 170.

[0212] With this configuration, the effect of the above-described embodiment 4 is also achieved, which is to maintain good gas output characteristics while achieving both lightweighting and cost reduction.

[0213] (Verification Experiment)

[0214] The following describes the verification tests conducted to confirm the effectiveness of the present invention. In the verification tests, cylindrical gas generators based on Verification Examples 1 to 3 of Embodiment 2 described above were actually manufactured, and cylindrical gas generators not based on Comparative Examples of Embodiment 2 described above were also manufactured. The gas output characteristics were measured by actually operating these cylindrical gas generators of Verification Examples 1 to 3 and Comparative Examples. Figure 14 This is a table that shows the test conditions and results of the verification test.

[0215] like Figure 14 As shown, the cylindrical gas generators involved in Verification Examples 1 to 3 are equipped with the aforementioned helical spring 170, thereby constraining the opening state of the cup 141c of the ignition section 141 by the helical spring 170 (see reference). Figure 8 (etc.). Here, in verification examples 1 to 3, the inner diameter of the helical spring 170 used is different, but the wire diameter, number of turns, etc. are the same on the other side.

[0216] On the other hand, the cylindrical gas generator involved in the comparative example does not have the aforementioned helical spring 170. Instead, by fixing only the pressing part 173 of the helical spring 170 to the housing body 110, the distance between the ignition part 141 of the igniter 140 and the gas generating agent 160 is configured to be equal to the distance of the cylindrical gas generator involved in the aforementioned verification examples 1 to 3.

[0217] Here, in the cylindrical gas generators involved in these verification examples 1 to 3 and comparative examples, the only differences between them are in the presence or absence of the helical spring and the inner diameter of the helical spring, while all other structural configurations are the same.

[0218] That is, the inner diameter R1 of the housing body 110 is 17.4 mm in each of them, and the outer diameter R2 of the ignition part 141 is 8.05 mm in each of them. In addition, the distance L1 from the portion of the ignition part 141 containing the igniter 141 to the gas generator 160 along the axial direction of the housing body 110 is 10.5 mm in each of them, and the distance L2 from the portion of the ignition part 141 containing the igniter 141 to the boundary between the cylindrical part 171 and the expanded diameter part 172 along the axial direction of the housing body 110 is 2.3 mm in each of them.

[0219] Furthermore, the clearance in the cylindrical gas generator involved in Verification Examples 1 to 3 is the clearance C mentioned above (i.e., the distance between the ignition part 141 and the cylindrical part 171), while the clearance in the cylindrical gas generator involved in the Comparative Example is the distance between the ignition part 141 and the housing body 110.

[0220] In the verification test, two samples were prepared for each of the cylindrical gas generators involved in verification examples 1-3 and comparative examples. Each sample was placed in a sealed chamber and operated, and the pressure change inside the chamber over time was measured. Additionally, Figure 14 The output parameters are used to evaluate gas output characteristics, representing the time from the igniter's operation to a change in pressure within the chamber.

[0221] like Figure 14 As shown, based on the results of the above verification tests, it was confirmed that in the cylindrical gas generators involved in Verification Examples 1 to 3, where the clearance C between the ignition section and the cylindrical section is 1.0 mm or less, the output performance was improved compared to the cylindrical gas generator involved in the Comparative Example without a helical spring. That is, by configuring the cup 141c of the ignition section 141 to restrict the opening state by the helical spring 170, it was experimentally confirmed that gas output was obtained earlier from the start of operation, and it was further confirmed that the output performance was improved more significantly as the clearance C was reduced.

[0222] (Other forms, etc.)

[0223] The characteristic structures shown in the above-described embodiments 1 to 5 and their variations of the present invention can, of course, be combined with each other without departing from the spirit of the present invention. For example, instead of the helical spring provided in the cylindrical gas generator according to embodiment 1, the cylindrical gas generator according to embodiment 1 may be equipped with one of the helical springs provided in the cylindrical gas generators according to embodiments 2 to 5.

[0224] Furthermore, in the embodiments 1 to 5 and their variations described above, an example was given of a helical spring configured to provide directionality to the thermal particles generated in the ignition section of the igniter. This helical spring is structured to include a cylindrical portion and an expanded diameter portion. However, it is not necessarily required to use a helical spring with such a shape. Various shapes of helical springs can be used, such as those with a thinner or thicker tip as a whole, those with multiple cylindrical or expanded diameter portions, or those with the same inner diameter except for the pressing portion. In any case, as long as the helical spring is configured to restrict the opening of the cup in the ignition section, the desired effect can be obtained. Furthermore, the wire diameter, number of turns, and material of the helical spring can, of course, be appropriately changed.

[0225] Furthermore, in the embodiments 1 to 5 and their variations described above, a cylindrical gas generator without an auto-ignition agent that ignites automatically without relying on the operation of an igniter was illustrated, but a cylindrical gas generator can also be constructed in a manner that includes such an auto-ignition agent. This auto-ignition agent is a substance that spontaneously ignites at a temperature lower than that of the gas generator, and is intended to prevent abnormal operation of the cylindrical gas generator due to external heating in the event of a fire in a vehicle or similar vehicle equipped with an airbag device containing a cylindrical gas generator. When this auto-ignition agent is placed in the cylindrical gas generator, it is sufficient, for example, to simply place the auto-ignition agent in the space within the combustion chamber and arrange it in contact with a partition member.

[0226] Furthermore, in the above-described embodiments 1 to 5 and their variations, the application of the present invention to a cylindrical gas generator installed in a side airbag device has been illustrated. However, the application of the present invention is not limited to this. It can also be applied to cylindrical gas generators installed in curtain airbag devices, knee airbag devices, seat cushion airbag devices, etc., or to so-called T-shaped gas generators that have an elongated shape similar to cylindrical gas generators.

[0227] Thus, the embodiments and variations disclosed herein are illustrative in all respects and not restrictive. The scope of the invention is defined by the claims, and includes all modifications within the same meaning and scope as the claims.

[0228] Explanation of reference numerals in the attached figures

[0229] 1. Cylindrical gas generator (1A-1H); 10 Housing body; 11 Gas outlet; 12, 13 Converging slits; 20 Retainer assembly; 20A Retainer part; 20B Connector part; 21 First body part; 21a Axial end face; 21b Outer peripheral surface; 22 Annular protrusion; 23a Receiving part; 23b Converging slit; 24 Second body part; 24a Inner peripheral surface; 25 Cylindrical part; 25a Inner peripheral surface; 26 Flange part; 27 Annular stepped surface; 28a First chamber; 28b Second chamber; 29 Sealing component; 30 Closing component; 31 Closing part; 32 Side wall part; 33 Annular recess; 40 Igniter; 41 Base; 42 Igniting part; 43 Terminal pin; 50 Separating component; 51 Partition wall part; 51a 52. Score; 52. Annular wall; 60. Gas generator; 70. Helical spring; 71. Spring part; 72. Pushing part; 80. Filter; 81. Hollow part; 90. Welding part; 110. Housing body; 111. Gas outlet; 112, 113. Converging part; 120. Retainer; 121. Through part; 122. Annular groove; 123. Converging part; 124. Recess; 125. Sealing component; 130. Closing component; 131. Annular groove; 140. Igniter; 141. Igniting part; 141a. Igniting powder; 141b. Plug; 141c. Cup body; 142. Terminal pin; 150. Separating component; 151. Partition wall; 151a. Score; 152. Annular wall; 153. O-ring; 160. Gas generator; 170. Helical spring; 171 Cylindrical section; 172 Expanded diameter section; 173 Pushing section; 180 Filter; 181 Hollow section; S1 Combustion chamber; S2 Filter chamber.

Claims

1. A gas generator, characterized in that, have: The cylindrical metal shell body includes a combustion chamber containing a gas generating agent inside; The retainer assembly is inserted into the axial open end of the aforementioned housing body, including a through-hole-shaped hollow opening extending in a direction parallel to the axial direction of the aforementioned housing body; and An igniter includes an ignition part that contains igniting powder and a terminal pin connected to the ignition part. When the ignition part is located on the combustion chamber side and the terminal pin is located on the opposite side to the combustion chamber side, at least a portion of the igniter is disposed inside the hollow opening. The aforementioned retainer assembly has a metal retainer portion and a resin connector portion. The retainer portion is located on the aforementioned combustion chamber side and receives and holds the aforementioned igniter. The connector portion is located on the opposite side to the aforementioned combustion chamber side and is capable of receiving a connector that connects to the aforementioned terminal pin. The aforementioned retainer portion includes a cylindrical first body portion defining the aforementioned hollow opening and an annular protrusion protruding from the aforementioned first body portion along the radial direction of the aforementioned housing body; The aforementioned connector portion includes a cylindrical second body portion defining the aforementioned hollow opening and a cylindrical portion extending from the aforementioned second body portion toward the aforementioned combustion chamber side; The aforementioned cylindrical portion is inserted into the aforementioned opening end of the aforementioned housing body, and is externally inserted into the portion of the aforementioned first body portion located on the opposite side to the aforementioned combustion chamber side when viewed from the aforementioned annular protrusion. By narrowing the diameter of the portion of the aforementioned housing body corresponding to the aforementioned cylindrical portion toward the radial inward, the aforementioned cylindrical portion is clamped and compressed by the aforementioned narrowed portion of the aforementioned housing body and the aforementioned first body portion, thereby sealing the gap between the aforementioned housing body and the aforementioned first body portion by the aforementioned cylindrical portion.

2. The gas generator as described in claim 1, characterized in that, The inner diameter of the aforementioned cylindrical portion is larger than the inner diameter of the aforementioned second body portion, and an annular stepped surface is provided in the aforementioned connector portion to connect the inner circumferential surface of the aforementioned second body portion with the inner circumferential surface of the aforementioned cylindrical portion. At the axial end of the aforementioned connector portion located on the aforementioned combustion chamber side, a first chamber is provided, defined by the aforementioned annular stepped surface and the inner circumferential surface of the aforementioned cylindrical portion. The aforementioned first body part is inserted into the aforementioned first chamber, and the axial end face of the aforementioned first body part located on the opposite side to the aforementioned combustion chamber side abuts against the aforementioned annular stepped surface.

3. The gas generator as described in claim 1 or 2, characterized in that, Since the inner diameter of the second body part is larger than the inner diameter of the first body part, a second chamber is provided at the axial end of the retainer assembly located on the side opposite to the combustion chamber side, defined by the axial end face of the first body part located on the side opposite to the combustion chamber side and the inner circumferential surface of the second body part. The aforementioned second chamber forms the receiving part of the connector that connects to the aforementioned terminal pin.

4. The gas generator as described in claim 1 or 2, characterized in that, The outer peripheral surface of the aforementioned first body section narrows as it moves toward the aforementioned combustion chamber side.

5. The gas generator as described in claim 1 or 2, characterized in that, It also has: The filter is disposed inside the aforementioned housing body; and The partition component, by being disposed inside the aforementioned housing body, divides the interior space of the aforementioned housing body axially into a filter chamber in which the aforementioned filter is disposed and the aforementioned combustion chamber; The aforementioned partition is fixed by being welded to the aforementioned housing body.

6. The gas generator as described in claim 1 or 2, characterized in that, It also includes a helical spring, which is clamped between the aforementioned retainer assembly and the aforementioned gas generator. By applying force to the aforementioned gas generator toward the side opposite to the side where the aforementioned retainer assembly is located while the aforementioned gas generator is being removed from the aforementioned ignition part, the aforementioned gas generator is fixed inside the aforementioned housing body. The aforementioned ignition part includes a cup body that cracks when the aforementioned igniter is ignited by the aforementioned igniting powder during operation; The aforementioned helical spring is arranged substantially coaxially with the aforementioned ignition part in such a way that it surrounds the aforementioned ignition part without any other components sandwiched between them, so that the opening state of the aforementioned cup body when it cracks is restricted by the aforementioned helical spring.

7. The gas generator as described in claim 6, characterized in that, The aforementioned ignition part is roughly cylindrical in shape; The aforementioned helical spring includes a cylindrical portion and an enlarged diameter portion. The cylindrical portion is located on the side of the aforementioned retainer assembly and has a fixed inner diameter. The enlarged diameter portion extends from the end of the aforementioned cylindrical portion on the side of the aforementioned gas generator toward the aforementioned gas generator, and its inner diameter increases as it approaches the aforementioned gas generator. The portion of the aforementioned helical spring that surrounds the aforementioned igniter is composed of the aforementioned cylindrical part.

8. The gas generator as described in claim 7, characterized in that, When the inner diameter of the portion of the aforementioned housing body containing the aforementioned gas generating agent is set to R1, the outer diameter of the aforementioned ignition part is set to R2, the distance from the portion of the aforementioned ignition part containing the aforementioned ignition powder to the aforementioned gas generating agent along the axial direction of the aforementioned housing body is set to L1, the distance from the portion of the aforementioned ignition part containing the aforementioned ignition powder to the boundary between the aforementioned cylindrical portion and the aforementioned enlarged diameter portion along the axial direction of the aforementioned housing body is set to L2, and the clearance between the aforementioned ignition part and the aforementioned cylindrical portion is set to C, the condition 0<C≤(R1-R2)×(L2 / L1) / 2 is satisfied.

9. The gas generator as described in claim 8, characterized in that, The aforementioned clearance is less than 1.0 mm.

10. The gas generator as claimed in claim 6, characterized in that, The portion of the aforementioned helical spring that surrounds the aforementioned ignition part comes into contact with the aforementioned ignition part.

11. The gas generator as claimed in claim 7, characterized in that, The portion of the aforementioned helical spring that surrounds the aforementioned ignition part comes into contact with the aforementioned ignition part.

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