Gas generator

Abstract

A gas generator (1A) is provided with an igniter (40) assembled at one end of a case, a closed container (60) disposed inside the case, and a coil spring (80) sandwiched between the one end of the case and the closed container (60). The closed container (60) is fused or broken by the operation of the igniter (40), and a gas generating agent (70) is housed in the closed container (60). The coil spring (80) is a member for fixing the closed container (60) inside the case. The coil spring (80) is disposed substantially coaxially with an ignition portion (41) in a manner of surrounding the ignition portion (41) without sandwiching other members between the ignition portion (41), so that the opening condition of a cup (41c) included in the ignition portion (41) of the igniter (40) when the cup (41c) is cracked is restricted by the coil spring (80).

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 end of the housing along the axial direction, 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 end of the housing along the axial direction, and a gas outlet is provided on the peripheral wall portion 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] Generally, it is important to keep the gas generating agent airtight in a gas generator. This is because if the gas generating agent absorbs moisture, the desired gas output characteristics may no longer be obtained.

[0008] In cylindrical gas generators, one method to prevent the gas generating agent from absorbing moisture is to contain the gas generating agent in a sealed container and place it inside the housing. This sealed container is composed of relatively fragile components that are prone 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 1) discloses a cylindrical gas generator employing this method.

[0009] In the cylindrical gas generator disclosed in the aforementioned announcement, a helical spring is provided between the sealed container disposed inside the housing and one end of the housing on which the igniter is assembled, applying force to the sealed container toward the other end of the housing. This helical spring is a component used to properly maintain the distance between the igniter assembled at one end of the housing and the gas generating agent contained in the sealed container while simultaneously securing the sealed container inside the housing.

[0010] Furthermore, in the gas generator disclosed in the aforementioned announcement, a generally cylindrical metal combustion control shroud is provided at one end of the housing to cover the ignition section of the igniter, which houses the igniter propellant. This combustion control shroud is a component used to efficiently guide the thermal particles generated in the igniter during operation toward the gas generating agent; more specifically, it is a component that directs the direction of travel of the thermal particles generated in the ignition section.

[0011] By making the gas generator into a cylindrical shape with this structure, good gas output characteristics can be obtained during operation.

[0012] Existing technical documents Patent documents Patent document 1: Japanese Patent Application Publication No. 2018-69924. Summary of the Invention

[0013] The problem that the invention aims to solve However, in the case of a cylindrical gas generator with the above-described structure, many parts need to be installed on one end of the housing, which not only increases the number of parts but also complicates the assembly process, resulting in increased manufacturing costs. Furthermore, reducing the number of parts would allow for a reduction in the overall weight of the gas generator.

[0014] Therefore, the present invention was made in view of the above-mentioned problems, and the object is to provide a gas generator that can achieve lightweighting and reduction of manufacturing costs while maintaining good gas output characteristics.

[0015] Methods used to solve problems The gas generator according to the present invention includes a housing, a gas generating agent, an igniter, a sealed container, and a helical spring. The housing is a long cylindrical component with a peripheral wall portion, closed at one end and the other end axially. The gas generating agent is disposed inside the housing. The igniter has an ignition part that houses an ignition powder for igniting the gas generating agent, and is assembled to one end of the housing such that the ignition part protrudes towards the interior of the housing. The sealed container is disposed inside the housing, defining a gas generating agent receiving chamber, and is composed of a component that melts or ruptures under the heat or pressure generated by the operation of the igniter. The helical spring is clamped between one end of the housing and the sealed container, and is a component used to fix the sealed container inside the housing by applying force to the sealed container towards the other end of the housing. The ignition part includes a cup that cracks when the ignition powder is ignited during the operation of the igniter. In the gas generator based on the present invention, the helical spring is arranged substantially coaxially with the ignition part and surrounds the ignition part without any other components sandwiched between them, so that the opening state of the cup body when the cup body cracks is restricted by the helical spring.

[0016] In the gas generator based on the present invention, the ignition part may be approximately cylindrical in shape, and in this case, the helical spring may also be approximately cylindrical in shape.

[0017] Based on the gas generator of the present invention described above, it is preferable that, given that the inner diameter of the gas generating agent receiving chamber is R1, the outer diameter of the ignition part is R2, the distance from the portion of the ignition part containing the igniting agent to the gas generating agent receiving chamber along the axial direction of the housing is L1, the distance from the portion of the ignition part containing the igniting agent to the sealed container along the axial direction of the housing is L2, and the clearance between the ignition part and the surrounding portion that surrounds the ignition part in the helical spring is C, the condition 0 < C ≤ (R1 - R2) × (L2 / L1) / 2 is satisfied.

[0018] In the gas generator based on the present invention described above, it is preferable that the clearance is 1.0 mm or less.

[0019] In the gas generator based on the present invention described above, the surrounding portion of the helical spring that surrounds the ignition portion may also contact the ignition portion.

[0020] Invention Effects According to the present invention, a gas generator can be provided that achieves lightweighting and cost reduction while maintaining good gas output characteristics. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cylindrical gas generator involved in Embodiment 1.

[0022] Figure 2 yes Figure 1 An enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator shown.

[0023] Figure 3 yes Figure 1 An enlarged cross-sectional view of the area near the partition of the cylindrical gas generator shown.

[0024] Figure 4 This is a diagram used to illustrate the preferred clearance range in the cylindrical gas generator according to Embodiment 1.

[0025] Figure 5 This is an enlarged cross-sectional view near the igniter of a modified example of the cylindrical gas generator according to Embodiment 1.

[0026] Figure 6 This is an enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator according to Embodiment 2.

[0027] Figure 7 This is an enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator according to Embodiment 3.

[0028] Figure 8 This is an enlarged cross-sectional view of the area near the igniter of the cylindrical gas generator involved in Comparative Example 1.

[0029] Figure 9 This is a table that shows the test conditions and results of the verification test. Detailed Implementation

[0030] 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.

[0031] (Implementation Method 1) Figure 1 This is a schematic diagram of the cylindrical gas generator involved in 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 3The structure of the cylindrical gas generator 1A according to this embodiment will be described.

[0032] like Figure 1 As shown, the cylindrical gas generator 1A 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 holder 20, and a blocking component 30.

[0033] Inside the housing, which consists of the housing body 10, the retainer 20, and the blocking component 30, are housed igniter 40, partition component 50, sealed container 60, gas generator 70, automatic ignition agent 71, partition component 72, spring-shaped component 73, coil spring 80, and filter 90, which are internal components. Furthermore, the combustion chamber S1, which mainly houses the gas generator 70, and the filter chamber S2, which houses the filter 90, are located inside the housing.

[0034] 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 20 is composed of a cylindrical component having a through portion 21 extending in the same direction as the axial direction of the housing body 10, and has an annular groove 22 for closure and fixing (described later) on its outer peripheral surface. The sealing component 30 is composed of a disc-shaped component with a predetermined thickness, and has an annular groove 31 for closure and fixing (described later) on its peripheral surface. These annular grooves 22 and 31 for closure and fixing are formed on the outer peripheral surface of the retainer 20 and the peripheral surface of the sealing component 30 in a circumferentially extending manner.

[0035] 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, such as SPCE. Alternatively, the shell body 10 can also be constructed from welded steel pipe, such as STKM.

[0036] In particular, when the shell body 10 is made of a pressure-formed rolled steel plate or an electric welded steel 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.

[0037] On the other hand, the retainer 20 and the blocking component 30 are made of metal components such as stainless steel, steel, aluminum alloy, and stainless steel alloy.

[0038] The retainer 20 is fixed to the housing body 10 in such a way that it closes one of the axial open ends of the housing body 10. Specifically, with the retainer 20 inserted into the aforementioned one open end of the housing body 10, the portion of the housing body 10 corresponding to the annular groove 22 provided on the outer peripheral surface of the retainer 20 is radially reduced in diameter and engages with the annular groove 22, thereby fixing the retainer 20 relative to the housing body 10. Thus, one axial end of the housing is formed by the retainer 20.

[0039] 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 groove 31 provided on the circumferential surface of the blocking member 30 is radially reduced inward and engaged with the annular groove 31, 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.

[0040] These slit fixations are octagonal slit fixations that cause the shell 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 shell body 10. As a result, slit portions 12 and 13 directly contact the annular groove portions 22 and 31, respectively, preventing gaps from forming between them.

[0041] Furthermore, the assembly structure of the retainer 20 and 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 made into separate parts, but may be constituted by a single component having a bottomed cylindrical shape.

[0042] like Figure 1 and Figure 2 As shown, the igniter 40 is assembled to one end of the housing along its axial direction by means of the retainer 20. The igniter 40 is a component for igniting the gas generator 70 and is arranged in a manner facing the interior space of the housing.

[0043] The igniter 40 includes an ignition section 41 and a pair of terminal pins 42. The ignition section 41 includes an ignition powder 41a, a plug 41b, and a cup 41c. The ignition powder 41a is housed within the ignition section 41 by being positioned within the space defined by the plug 41b and the cup 41c. Furthermore, inside the ignition section 41, a resistor (bridge wire) is mounted in connection with the pair of terminal pins 42, and the ignition powder 41a is filled within the ignition section 41 either by surrounding or by being in contact with the resistor. Additionally, a ignition charge is loaded into the ignition section 41 as needed.

[0044] 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), or lead trinitroresorcinol are generally used. Furthermore, as the igniter, compositions consisting of metal powders / oxidants such as 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. Additionally, the cup 41c provided at the ignition section 41 includes a metal cup.

[0045] When a collision is detected, a predetermined amount of current flows through the resistive element via terminal pin 42. This flow of current generates Joule heating within the resistive element, causing the ignition charge 41a to ignite. The high-temperature heat particles generated by combustion cause the cup 41c containing the ignition charge 41a 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.

[0046] Furthermore, the igniter 40 is fixed to the retainer 20 by means of a slit 23 provided in the retainer 20. More specifically, the retainer 20 has a slit 23 at its axial end facing the interior space of the housing for fixing the igniter 40. When the igniter 40 is inserted into the through portion 21 and abuts against the wall of a portion of the through portion 21 of the retainer 20 and is blocked, the aforementioned slit 23 is slit, thereby clamping and fixing the igniter 40 in the retainer 20.

[0047] Thus, the igniter 40 is assembled into the retainer 20 with its ignition part 41 protruding toward the interior of the housing. Therefore, when the igniter 40 is in operation, the ignition powder 41a is ignited, causing the cup body 41c to crack, and the cup body 41c opens as a result of this cracking.

[0048] At the axial end of the retainer 20 that is exposed to the outside, a recess 24 is provided, continuous with the through portion 21 described above. The recess 24 forms a female connector portion that receives a male connector (not shown) for connecting the igniter 40 to the control unit (not shown). A portion near the front end of the terminal pin 42 of the igniter 40 is exposed and positioned within this recess 24. The male connector is inserted into the recess 24, which serves as the female connector portion, thereby achieving electrical connection between the core wire of the electrical wiring and the terminal pin 42.

[0049] like Figure 1 and Figure 3As 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.

[0050] 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 positioned such that the outer surface of its partition wall 51 abuts against the filter 90, and the outer peripheral surface of the annular wall 52 abuts against the inner peripheral surface of the housing body 10.

[0051] A score 51a is provided on the main surface of the partition wall 51 that abuts against the filter 90. 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 70. For example, it is composed of multiple grooves arranged radially and intersecting each other. The score 51a is provided at the portion opposite to the hollow portion 91 in the filter 90.

[0052] like Figures 1 to 3 As shown, a sealed container 60 and a coil spring 80 are arranged in the space (i.e., combustion chamber S1) between the retainer 20 and the partition member 50 inside the housing. In addition, a gas generating agent containing chamber S1A, which is the space inside the sealed container 60, contains a gas generating agent 70, an automatic ignition agent 71, a partition member 72, and a spring-shaped member 73.

[0053] The sealed container 60 is a component used to seal the gas generating agent 70 contained inside, and is made of fragile components that melt or rupture under the heat or pressure generated by the operation of the igniter 40. The sealed container 60 has a generally cylindrical shape with both ends closed, and is arranged generally coaxially with the shell.

[0054] More specifically, the sealed container 60 includes a container body 61 and a cover 62. By joining these container bodies 61 and cover 62, the aforementioned gas generating agent containment chamber S1A is formed inside the sealed container 60.

[0055] The container body 61 has a flat top wall portion 61a and a cylindrical side wall portion 61b extending from the periphery of the top wall portion 61a. On the other hand, the lid 62 has: a flat bottom portion 62a, which is located inside the container body 61 by being inserted into the open end 61b1 of the container body 61; and a rolled-up portion 62b, which extends from the periphery of the bottom portion 62a, a portion of which is bent to cover the inner peripheral surface, end surface and outer peripheral surface of the open end 61b1 of the container body 61.

[0056] Here, the engagement of the container body 61 and the lid 62 described above occurs between the open end 61b1 of the container body 61 and the rolled-up portion 62b of the lid 62, which is provided to cover it. More specifically, the engagement of the container body 61 and the lid 62 is achieved by providing a first converging portion 62b1 and a second converging portion 62b2 in the rolled-up portion 62b, which is provided to cover the open end 61b1 of the container body 61. Both the first converging portion 62b1 and the second converging portion 62b2 are formed by radially reducing the diameter of a predetermined portion of the container body 61.

[0057] As described above, both the container body 61 and the cover 62 are made of fragile components that melt or crack under the heat or pressure generated by the operation of the igniter 40. More specifically, the cover 62 is made of fragile components that melt or crack under the heat or pressure generated by the combustion of the igniter 41a or other igniter propellant when the igniter 40 is activated, and the container body 61 is made of fragile components that melt or crack under the heat or pressure generated by the combustion of the gas generating agent 70 when the igniter 40 is activated.

[0058] Specifically, the container body 61 and the cover body 62 are preferably made of pressure-formed metals such as copper, aluminum, copper alloy, and aluminum alloy. By joining them as described above, the gas generator 70 contained inside is sealed airtightly from the outside.

[0059] The sealed container 60 is inserted into the housing body 10 such that the top wall 61a of the container body 61 is located on the side of the partition member 50 and the bottom 62a of the cover 62 is located on the side of the retainer 20. Thus, the bottom 62a of the cover 62 faces the ignition part 41 of the igniter 40.

[0060] More specifically, the end of the sealed container 60 located on one side of the top wall 61a is inserted into the interior of the partition member 50 and thus engages with the partition member 50, while the end of the sealed container 60 located on one side of the bottom 62a is loosely fitted into the housing body 10. Thus, the sealed container 60 is positioned and fixed relative to the housing body 10, and is disposed at a predetermined distance from the inner circumferential surface of the housing body 10.

[0061] Therefore, an insulating layer S1B of a predetermined size is formed between the shell body 10, which constitutes the peripheral wall portion of the shell, and the side wall portion 61b of the sealed container 60. The insulating layer S1B extends in a generally cylindrical shape along the axial direction of the combustion chamber S1.

[0062] In this way, by providing a cylindrical heat insulation layer S1B between the sealed container 60 containing the gas generator 70 and the housing body 10, even in the event of a fire in a vehicle or the like equipped with an airbag device containing the cylindrical gas generator 1A, the gas generator 70 can be effectively prevented from being heated from the outside and rising in temperature.

[0063] That is, by providing an insulating layer S1B on the radially outer portion of the sealed container 60 containing the gas generator 70, this insulating layer S1B acts as a thermal barrier, making it difficult for heat from the housing body 10 to be conducted to the gas generator 70. This allows the temperature of the gas generator 70 to be suppressed to a relatively low level when the automatic ignition action initiated by the automatic ignition agent 71 (described later) occurs. Therefore, the rise in internal pressure of the housing during automatic ignition can be significantly suppressed.

[0064] Here, the insulation layer S1B preferably has a lower thermal conductivity than the shell body 10, and in this embodiment, it is composed of an air layer. However, the insulation layer S1B does not necessarily have to be an air layer; it can also be composed of a gas layer filled with other gases, or it can be composed of a vacuum layer. Furthermore, in addition to this, the insulation layer S1B can also be constructed by arranging various insulation components in this space.

[0065] An automatic ignition agent 71 and a partitioning member 72 are disposed at the end of the gas generating agent containing chamber S1A formed inside the sealed container 60 on the side of the partition member 50, and a spring-shaped member 73 is disposed at the end of the retainer 20 on the side of the container 60. On the other hand, a gas generating agent 70 is disposed in the portion of the gas generating agent containing chamber S1A formed inside the sealed container 60 other than the ends on the side of the partition member 50 and the ends on the side of the retainer 20.

[0066] The gas generator 70 is a reagent that is ignited by thermal particles generated by the operation of the igniter 40 to produce gas. As the gas generator 70, a non-azide gas generator is preferred, and the gas generator 70 is generally constructed as a shaped body containing fuel, oxidant and additives.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] The gas generator 70 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 1A is installed; for example, shapes that allow the gas generation rate to change over time during combustion of the gas generator 70 are preferred, and are the optimal shapes corresponding to the specifications. Furthermore, 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 70 but also factors such as the linear combustion rate and pressure index of the gas generator 70.

[0071] The automatic ignition agent 71 is an agent that ignites automatically regardless of the operation of the igniter 40. In this embodiment, it is composed of a projectile shaped into a flat, approximately cylindrical shape. This automatic ignition agent 71 is an agent that ignites spontaneously at a lower temperature than the gas generator 70. It is designed to prevent abnormal operation of the cylindrical gas generator 1A due to external heating in the event of a fire in vehicles or similar vehicles equipped with airbag devices containing a cylindrical gas generator 1A.

[0072] The partitioning component 72 is used to partition the gas generating agent containing chamber S1A along the axial direction of the housing. The partitioning component 72 has a positioning recess 72a on the axial direction of the peripheral wall of the housing body 10 facing the partitioning component 50, and a skirt-shaped fixing cylindrical portion 72b at its outer edge. Furthermore, at the bottom of the positioning recess 72a of the partitioning component 72, one or more through holes 72c are provided to allow communication between the pair of spaces partitioned by the partitioning component 72 (i.e., the space containing the gas generating agent 70 and the space containing the automatic ignition agent 71).

[0073] Here, the dividing component 72 is preferably made of a metal pressure-formed part, for example, preferably made of brass that will not break or melt even when burned by the gas generator 70. However, there is no necessity for the dividing component 72 to be made of brass, and it can also be made of stainless steel, steel, iron, aluminum, aluminum alloy, etc.

[0074] Furthermore, it is not necessary to provide a through hole 72c in the dividing member 72. It can also be configured such that a through hole is formed in the dividing member 72 by providing a groove, and the through hole is formed in the dividing member 72 as the gas generating agent 70 burns. Alternatively, the dividing member 72 can be constructed without providing a through hole or groove, and the dividing member 72 itself can be constructed with a fragile component that breaks or melts due to the combustion of the gas generating agent 70.

[0075] The partition component 72 is inserted into the side wall portion 61b of the container body 61 of the sealed container 60, and the fixing cylindrical portion 72b of the partition component 72 abuts against the inner circumferential surface of the side wall portion 61b. That is, the partition component 72 is pressed into the side wall portion 61b of the container body 61, thereby fixing the partition component 72 to the sealed container 60.

[0076] A portion of an auto-ignition agent 71, shaped like a bullet, is housed in a positioning recess 72a provided in the partition member 72. Thus, the auto-ignition agent 71 is sandwiched between the bottom of the positioning recess 72a of the partition member 72 and the top wall 61a of the container body 61. Consequently, the auto-ignition agent 71 comes into contact with both the partition member 72 and the container body 61.

[0077] With this configuration, the auto-ignition agent 71 is in substantially shortest path thermal contact with the housing body 10 via the partition member 72, which is a metal component, the end near the top wall 61a of the sealed container 60, which is a metal component, and the separator member 50, which is a metal component.

[0078] Therefore, in the event of a fire in a vehicle or similar situation, the timing of the automatic ignition action initiated by the automatic ignition agent 71 is advanced, resulting in a relatively low temperature of the gas generator 70 at the time of the automatic ignition action. Consequently, the increase in internal pressure of the housing during the automatic ignition action can be significantly suppressed.

[0079] The spring-shaped component 73 is provided to prevent the gas generator 70, which is made of a molded body, from being crushed due to vibration or other reasons. It has a spring portion 73a formed by bending metal wire and a pressing portion 73b. The spring portion 73a is arranged such that one end abuts against the bottom 62a of the sealed container 60, and the pressing portion 73b is formed at the other end. The pressing portion 73b is constructed, for example, by arranging metal wires at predetermined intervals in a substantially parallel manner, and abuts against the gas generator 70.

[0080] Therefore, the gas generator 70 is elastically forced towards the separating member 50 by the spring-shaped member 73, preventing it from moving inside the sealed container 60. Alternatively, instead of the spring-shaped member 73, a cushioning material made of components such as ceramic fiber molded bodies, asbestos, foamed resins (e.g., foamed silicone, foamed polypropylene, foamed polyethylene, etc.), or rubbers such as chloroprene and EPDM can be used.

[0081] In the combustion chamber S1, in the space located on the side closer to the retainer 20 than the sealed container 60, a helical spring 80 is disposed as a component other than the aforementioned spring-shaped member 73. The helical spring 80 is formed by winding metal wire into a helical shape, and unlike the aforementioned spring-shaped member 73, it does not have the pushing portion 73b present in the latter. In this embodiment, by winding the metal wire in a manner that maintains the same inner diameter at all axial positions, the helical spring 80 as a whole has a generally cylindrical shape.

[0082] The helical spring 80 is a component used to secure the sealed container 60 inside the housing while absorbing dimensional discrepancies of the various constituent parts housed within the housing. Furthermore, the helical spring 80 is a component used to properly maintain the distance from the igniter 40 assembled at one end of the housing to the gas generating agent 70 housed within the sealed container 60.

[0083] Therefore, the helical spring 80 is clamped between one end of the housing in the axial direction and the sealed container 60, with one end positioned to abut against the retainer 20 and / or the igniter 40, and the other end positioned to abut against the end of the sealed container 60 on the retainer 20 side. Thus, the sealed container 60 is elastically forced towards the partition member 50, which is the other end of the housing in the axial direction, by the helical spring 80, and is fixed relative to the housing by being clamped by the partition member 50 and the helical spring 80.

[0084] Here, the coil spring 80 is arranged to surround the ignition portion 41 of the igniter 40, which has a generally cylindrical shape. More specifically, the coil spring 80 is arranged substantially coaxially with the ignition portion 41, surrounding it without any other components sandwiched between them. Thus, the coil spring 80 includes a wound portion 81 that is the part surrounding the ignition portion 41, and an extension portion 82 that is also wound, located on the side closer to the sealed container 60 than the wound portion 81 (see reference). Figure 4 ).

[0085] With this configuration, when the igniter 40 is in operation, if the cup 41c of the ignition part 41 cracks, the opening state of the cup 41c is restricted by the coil spring 80, the details of which will be described later.

[0086] like Figure 1 As shown, a filter 90 is disposed in the space (i.e., filter chamber S2) between the blocking member 30 and the separating member 50 inside the housing. The filter 90 is composed of a cylindrical member having a hollow portion 91 extending in the same direction as the axial direction of the housing body 10, one end face of which abuts against the blocking member 30 and the other end face of which abuts against the separating member 50.

[0087] When gas generated by the combustion of the gas generator 70 passes through the filter 90, 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 90, 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.

[0088] As the filter 90, a structure preferably made of an assembly of metal wires or metal meshes made of stainless steel, steel, or the like can be used. Specifically, an assembly of knitted metal mesh, plain woven metal mesh, rolled metal wires, or a structure that has been pressed together by pressure can be used.

[0089] Furthermore, as the filter 90, 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 has been processed into a mesh shape by setting slits in an interlaced pattern on the metal plate and expanding it to form holes, or a hook metal plate that has been flattened by perforating the metal plate and flattening the burrs generated around the holes.

[0090] In the housing body 10 of the portion defining the filter chamber S2, 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 90 to the outside of the housing.

[0091] Next, refer to Figure 1 The operation of the cylindrical gas generator 1A according to this embodiment will be described.

[0092] Reference Figure 1 In the event of a collision involving a vehicle equipped with the cylindrical gas generator 1A described in this embodiment, a collision detection mechanism separately installed in the vehicle detects the collision, and based on this, the igniter 40 is activated by energizing a control unit separately installed in the vehicle.

[0093] If the igniter 40 is working, the ignition powder 41a or other igniter powder also burns, the pressure inside the ignition part 41 rises, and the cup 41c of the ignition part 41 cracks, so that the hot particles generated by the combustion of the ignition powder 41a flow out to the outside of the ignition part 41.

[0094] The hot particles flowing out from the ignition section 41 are directed by the aforementioned helical spring 80, thereby reaching the bottom 62a of the sealed container 60. As a result, under the heat or pressure generated by the operation of the igniter 40, the bottom 62a of the sealed container 60 melts or ruptures, and the aforementioned hot particles reach the gas generating agent 70.

[0095] The hot particles that reach the gas generator 70 cause the gas generator 70 to burn, thereby producing a large amount of gas. Subsequently, the pressure and temperature of the gas generator containment chamber S1A rise, the side wall 61b of the sealed container 60 ruptures or melts, and the auto-ignition agent 71 burns, which in turn causes the top wall 61a of the sealed container 60 to rupture or melt.

[0096] As the gas generator 70 burns, the overall pressure of the combustion chamber S1 increases further. When the internal pressure of the combustion chamber S1 reaches the specified pressure, it breaks at the part of the partition member 50 where the notch 51a is provided. As a result, a connecting hole is formed in the partition member 50 at the part opposite to the hollow part 91 of the filter 90, so that the combustion chamber S1 and the filter chamber S2 are connected through the connecting hole.

[0097] Subsequently, the gas generated in the combustion chamber S1 flows into the filter chamber S2 through the connecting hole formed in the partition member 50. The gas flowing into the filter chamber S2 flows axially in the hollow portion 91 of the filter 90 and then changes direction radially, circulating inside the filter 90. At this time, heat is taken away by the filter 90 and the gas is cooled, and the slag contained in the gas is removed by the filter 90.

[0098] Then, the gas flowing through the filter 90 is ejected to the outside of the housing through the gas outlet 11. The ejected gas is introduced into the interior of the air bladder located adjacent to the cylindrical gas generator 1A, causing the air bladder to inflate and deploy.

[0099] Here, as Figure 2 As shown, in the cylindrical gas generator 1A according to this embodiment, as described above, the helical spring 80, which is clamped between one axial end of the housing (i.e., the retainer 20) and the sealed container 60, is arranged substantially coaxially with the ignition part 41 in such a way that it surrounds the ignition part 41 of the igniter 40 without clamping any other components between it and the ignition part 41 of the igniter 40.

[0100] With this configuration, firstly, the ignition part 41 is surrounded by the coil spring 80 (see reference). Figure 4 The surrounding structure can suppress cracking or outward deformation of the side wall portion of the cup 41c when the cup 41c of the ignition part 41 cracks. Therefore, the opening can be formed mainly at the front end of the portion of the cup 41c located on the side of the gas generator 70.

[0101] Furthermore, secondly, when the cup body 41c of the ignition part 41 cracks and an opening is formed at the front end of the cup body 41c, the opened portion of the cup body 41c interacts with the extension 82 in the coil spring 80 (see reference). Figure 4 The contact between the coil spring 80 and the cup 41c can suppress further outward deformation. Therefore, the extension 82 of the coil spring 80 and the open portion of the cup 41c also function as guides to determine the direction of travel of the thermal particles.

[0102] Therefore, the direction of travel of the hot particles generated in the ignition section 41 is concentrated along the axial direction of the housing body 10, which can efficiently guide the hot particles toward the gas generator 70. Therefore, the coil spring 80 not only functions to fix the aforementioned sealed container 60 inside the housing, but also functions to efficiently guide the hot particles generated in the igniter 40 during operation toward the gas generator 70, eliminating the need for components such as the combustion control shroud that were previously required.

[0103] In this way, by using the cylindrical gas generator 1A 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 of the gas generator as a whole. Therefore, it is possible to achieve both weight reduction and manufacturing cost reduction while maintaining good gas output characteristics.

[0104] Furthermore, in order to efficiently guide the hot particles generated by the ignition section 41 towards the gas generator 70, it is necessary to impart a suitable degree of 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 41 and the surrounding portion 81, which is the part of the coil spring 80 that surrounds the ignition section 41. Hereinafter, refer to... Figure 4 The preferred range for this clearance is explained. Figure 4 This is a diagram used to illustrate the preferred clearance range of the cylindrical gas generator according to this embodiment.

[0105] From the viewpoint of preventing cracking or deformation at the side wall portion of the cup body 41c, it is preferable that there is no gap between the ignition part 41 and the surrounding part 81. However, it is not necessarily easy to press the helical spring 80, which is made of metal wire, into the ignition part 41. From the viewpoint of simplifying the assembly operation, it is preferable to provide the aforementioned gap slightly.

[0106] Based on the results of the verification tests described later, it was confirmed that the clearance is preferably at least 1.0 mm or less. However, if the extension 82 and the opened portion of the cup 41c are also considered to function as a guide, the upper limit can be determined as follows.

[0107] That is, in reference Figure 4 Let the inner diameter of the gas generating agent containment chamber S1A be R1, the outer diameter of the ignition part 41 be R2, the distance from the portion of the ignition part 41 containing the igniter 41a to the gas generating agent containment chamber S1A along the axial direction of the shell body 10 be L1, and the distance from the portion of the ignition part 41 containing the igniter 41a to the sealed container 60 along the axial direction of the shell body 10 be L2. In this case, the clearance C between the ignition part 41 and the surrounding part 81 preferably satisfies the condition 0 < C ≤ (R1 - R2) × (L2 / L1) / 2.

[0108] By satisfying the above conditions, as observed from the ignition section 41, the gas generating agent containment chamber S1A is located within the range of the portion of the hot particles guided by the extension 82 and the cup body 41c, thus enabling very efficient guidance of hot particles to the gas generating agent containment chamber S1A. Therefore, satisfying this condition is preferable in order to reliably obtain the above-mentioned effect.

[0109] Figure 5 This is an enlarged cross-sectional view near the igniter, showing an example of a modified example of the cylindrical gas generator according to this embodiment. Figure 5 As shown, the cylindrical gas generator 1A' uses a different helical spring 80' than the helical spring 80 described above, compared to the cylindrical gas generator 1A described above.

[0110] That is, the helical spring 80' is configured such that, compared to the helical spring 80 described above, the metal wire has a thicker diameter, a larger inner diameter, and therefore more turns. With this configuration, the aforementioned effects can also be achieved.

[0111] Thus, the inner diameter of the helical spring, which determines the size of the clearance between the ignition part 41 and the surrounding part 81, can be varied according to various requirements, not just the diameter of the metal wire constituting the helical spring and the number of turns. For example, from the viewpoint of facilitating assembly and reducing weight, a thinner wire diameter is preferred, while a thicker wire diameter is preferred from the viewpoint of more securely fixing the sealed container and improving the directionality of the heat particles. Furthermore, from the viewpoint of reducing weight, a fewer number of turns of the metal wire is preferred, while a more numerous number of turns is preferred from the viewpoint of improving the directionality of the heat particles. Moreover, the material of the metal wire constituting the helical spring can also be varied.

[0112] (Implementation Method 2) Figure 6 This is an enlarged cross-sectional view of the vicinity of the igniter in the cylindrical gas generator according to Embodiment 2. Next, referring to this... Figure 6 The cylindrical gas generator 1B according to this embodiment will be described.

[0113] like Figure 6 As shown, compared with the cylindrical gas generator 1A of Embodiment 1 described above, the inner diameter of the helical spring 80 in the cylindrical gas generator 1B of this embodiment is different. Therefore, the surrounding portion 81 (refer to) that surrounds the ignition part 41 in the helical spring 80 is different. Figure 4 The ignition part 41 is in contact with the surrounding part 81. That is, in the cylindrical gas generator 1B according to this embodiment, there is no clearance between the ignition part 41 and the surrounding part 81.

[0114] In this configuration, the coil spring 80 needs to be pressed into the ignition part 41 during assembly. Although the workability is slightly worse than with a clearance, it more reliably prevents cracking and deformation at the side wall of the cup body 41c. Therefore, with the structure of this embodiment, similar to the case of Embodiment 1 described above, it is possible to maintain good gas output characteristics while achieving both lightweighting and cost reduction.

[0115] (Implementation Method 3) Figure 7 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 7 The cylindrical gas generator 1C according to this embodiment will be described.

[0116] like Figure 7 As shown, the cylindrical gas generator 1C according to this embodiment differs in shape from the cylindrical gas generator 1A according to Embodiment 1 described above. Specifically, the cylindrical gas generator 1C according to this embodiment has a reduced diameter portion (i.e., a portion with a relatively small inner diameter) at its central portion in the axial direction, and expanded diameter portions (i.e., portions with a relatively large inner diameter) at both ends in the axial direction.

[0117] Here, the reduced diameter portion and the expanded diameter portion of the aforementioned coil spring 80 are positioned to surround the ignition portion 41 of the igniter 40. These portions correspond to the aforementioned surrounding portion 81 (see reference). Figure 4 Furthermore, the reduced-diameter portion of the coil spring 80 that surrounds the ignition portion 41 of the igniter 40 is pressed into the ignition portion 41 to make contact with it. That is, in the cylindrical gas generator 1C according to this embodiment, there is no clearance between the ignition portion 41 and the reduced-diameter portion in the surrounding portion 81.

[0118] In this configuration, the coil spring 80 needs to be pressed into the ignition part 41 during assembly. Although this makes it less workable than the configuration with clearance, it more reliably prevents cracking and deformation of the side wall of the cup body 41c. Therefore, with the structure of this embodiment, similar to the case of Embodiment 1 described above, it is possible to maintain good gas output characteristics while achieving both lightweighting and cost reduction.

[0119] Furthermore, by providing enlarged diameter portions at both ends of the helical spring 80 in the axial direction as in this embodiment, the insertion direction of the helical spring 80 is no longer restricted during assembly, and the helical spring 80 can be pressed into the ignition portion 41 more easily.

[0120] (Verification Experiment) 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 5 of Embodiment 1 described above were actually manufactured, and cylindrical gas generators not based on Comparative Examples 1 and 2 of Embodiment 1 described above were also manufactured. By actually operating these cylindrical gas generators of Verification Examples 1 to 5 and Comparative Examples 1 and 2, the gas output characteristics were measured.

[0121] Figure 8 This is an enlarged cross-sectional view of the vicinity of the igniter in the cylindrical gas generator involved in Comparative Example 1. Furthermore, Figure 9 This is a table that shows the test conditions and results of the verification test.

[0122] like Figure 9 As shown, none of the cylindrical gas generators involved in Verification Examples 1 to 5 possess the combustion control hood 43 (see Comparative Example 1X described later) that is present in the cylindrical gas generator 1X. Figure 8 The structure consists of a cup 41c of the ignition part 41 restricted by a helical spring 80 (see reference). Figure 2 The opening status of (etc.). Here, in verification examples 1 to 5, the inner diameter, wire diameter, and number of turns of the helical spring 80 used are different, but their free lengths are the same on the opposite sides.

[0123] On the other hand, such as Figure 8 As shown, in the cylindrical gas generator 1X of Comparative Example 1, a generally cylindrical metal combustion control shroud 43 is externally inserted into the ignition section 41 of the igniter 40. The combustion control shroud 43 is a component used to efficiently guide the hot particles generated in the igniter 40 during operation to the gas generating agent 70. The combustion control shroud 43, together with the igniter 40, is fixed to the retainer 20 by a slit 23 provided at the retainer 20.

[0124] In the cylindrical gas generator 1X described in Comparative Example 1, instead of the helical spring 80 described in Embodiment 1 above, the combustion control shroud 43 directs the hot particles generated in the ignition section 41. Therefore, in the cylindrical gas generator 1X described in Comparative Example 1, the helical spring 80 is only provided to fix the sealed container 60 inside the housing; this helical spring 80 is not a constraint on the cup 41c of the ignition section 41 (see [reference]). Figure 2 Components that indicate the open status (e.g., etc.).

[0125] Furthermore, although the illustrations are omitted, the cylindrical gas generator involved in Comparative Example 2 is a structure of the cylindrical gas generator 1X involved in Comparative Example 1 above, except that the combustion control shroud 43 has been removed. Here, in the cylindrical gas generator 1X involved in Comparative Example 2, although the helical spring 80” is positioned facing the ignition part 41, since the helical spring 80” is arranged relatively far away from the ignition part 41, as will be clear from the test results described later, the helical spring 80” will not restrict the cup body 41c of the ignition part 41 (see reference). Figure 2 The opening status of (etc.).

[0126] Here, in the cylindrical gas generators involved in these verification examples 1 to 5 and comparative examples 1 and 2, the configurations differ only in the structure of the aforementioned helical spring and combustion control hood, while all other structural configurations are identical. The inner diameter R1 of the gas generating agent containment chamber S1A is 16.1 mm, the outer diameter R2 of the ignition part 41 is 8.2 mm, the distance L1 from the portion of the ignition part 41 containing the igniter 41a to the gas generating agent containment chamber S1A along the axial direction of the housing body 10 is 11.1 mm, and the distance L2 from the portion of the ignition part 41 containing the igniter 41a to the sealed container 60 along the axial direction of the housing body 10 is 2.9 mm.

[0127] In the verification test, five samples of each of the cylindrical gas generators involved in verification examples 1-5 and comparative examples 1 and 2 were prepared. Each sample was placed in a sealed chamber and operated, and the pressure change inside the chamber over time was measured. Additionally, Figure 9 The output index is an indicator used to evaluate gas output characteristics, representing the time from the igniter's operation to the change in pressure within the chamber.

[0128] like Figure 9As shown, it was confirmed that in the cylindrical gas generators of Verification Examples 1 to 4, where the clearance C between the ignition section and the surrounding section is 1.0 mm or less, the same gas output characteristics as those of the cylindrical gas generator of Comparative Example 1, which is equipped with a combustion control hood, can be obtained. In particular, it was confirmed that in the cylindrical gas generators of Verification Examples 1 to 3, compared with the cylindrical gas generator of Comparative Example 1, the above-mentioned output indicators are improved, and gas output can be obtained earlier from the start of operation.

[0129] On the other hand, in the cylindrical gas generator involved in Verification Example 5, where the clearance C between the ignition part and the surrounding part is 1.9 mm, only the same gas output characteristics as those of the cylindrical gas generator involved in Comparative Example 2, which does not have a combustion control hood, can be obtained. This experimentally confirms that the clearance C between the ignition part and the surrounding part is still an important factor.

[0130] In addition, Figure 9 In the above-mentioned verification examples 1 to 5 and comparative examples 1 and 2, the evaluation of manufacturing cost and gas output characteristics is expressed as "good" or "acceptable", and the comprehensive evaluation based on these two evaluations is expressed as "excellent", "good" or "acceptable".

[0131] (Other forms, etc.) In the above-described embodiments and variations of the present invention, examples were given of helical springs that impart directionality to the thermal particles generated in the ignition section of the igniter. These helical springs were generally cylindrical in shape as a whole, with the metal wire wound in such a manner that the inner diameter is the same at all positions in the axial direction. Alternatively, helical springs with partially different inner diameters were also used. However, it is not necessarily necessary to use helical springs with such shapes; helical springs that are configured as a whole with a thinner or thicker tip can also be used. In either case, as long as the helical spring is configured to restrict the opening state of the cup in the ignition section, the corresponding effect can be obtained.

[0132] Furthermore, in the embodiments and variations thereof described above, the case where one end of the helical spring abuts against a slit provided at the retainer for fixing the igniter has been illustrated. However, this end of the helical spring may also abut against a surface of the retainer located further outward than the slit. Moreover, as described above, one end of the helical spring does not necessarily need to abut against the retainer; it may be fixed simply by pressing it into the ignition part without abutting against it.

[0133] Furthermore, in the embodiments and variations thereof described above, the application of the invention to a cylindrical gas generator configured to form an insulation layer inside the housing and on the radially outer side of the sealed container was illustrated. However, this insulation layer is not necessarily a necessary structure. That is, the invention can also be applied to a cylindrical gas generator without such an insulation layer, in which case the sealed container is pressed into the housing body, with the sidewall of the sealed container abutting against the inner circumferential surface of the housing body.

[0134] Furthermore, in the above-described embodiments and variations of the present invention, the application of the present invention to a cylindrical gas generator that houses not only the gas generating agent, but also the automatic ignition agent, the partitioning component, and the helical spring in a sealed container has been described. However, such a configuration is not necessarily required, as long as the gas generating agent is at least housed in a sealed container.

[0135] Furthermore, in the above-described embodiments and variations of the present invention, the application of the present invention to a cylindrical gas generator installed in a side airbag device has been described. 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 the same elongated shape as cylindrical gas generators.

[0136] 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.

[0137] Explanation of reference numerals in the attached figures 1A, 1A', 1B, 1X Cylindrical gas generator; 10 Housing body; 11 Gas outlet; 12, 13 Converging slits; 20 Retainer; 21 Through section; 22 Annular groove; 23 Converging slit; 24 Recess; 30 Closing component; 31 Annular groove; 40 Igniter; 41 Igniting part; 41a Igniting powder; 41b Plug; 41c Cup body; 42 Terminal pin; 43 Combustion control cover; 50 Separating component; 51 Partition wall; 51a Score; 52 Annular wall; 60 Sealed container; 61 Container body; 61a Top wall; 61b Side wall; 61b1 Open end; 62 Cover; 62a Bottom; 62b Wrap-in section; 62b1 First converging slit; 62b2 2. Seam section; 70. Gas generator; 71. Automatic ignition agent; 72. Dividing component; 72a. Positioning recess; 72b. Fixing cylinder; 72c. Through hole; 73. Spring-shaped component; 73a. Spring section; 73b. Pushing section; 80, 80', 80”. Helical springs; 81. Surrounding section; 82. Extension section; 90. Filter; 91. Hollow section; S1. Combustion chamber; S1A. Gas generator housing chamber; S1B. Insulation layer; S2. Filter chamber.

Claims

1. A gas generator, characterized in that, have: A long, cylindrical shell, with one and the other ends closed in the axial direction, and having a peripheral wall portion; The gas generator is disposed inside the aforementioned housing; The igniter has an ignition part that contains an ignition powder for igniting the aforementioned gas generator, and is assembled to one end of the aforementioned housing in such a way that the ignition part protrudes toward the interior of the aforementioned housing. A sealed container, disposed inside the aforementioned housing, defines a gas generating chamber containing the aforementioned gas generating agent, and is subject to heat or pressure generated by the operation of the aforementioned igniter; and A helical spring is clamped between the aforementioned end of the aforementioned housing and the aforementioned sealed container, and is used to fix the aforementioned sealed container inside the aforementioned housing by applying force to the aforementioned other end of the aforementioned housing. The aforementioned ignition part includes the 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, surrounding the aforementioned ignition part without any other components sandwiched between them, so that the opening state of the aforementioned cup body in the event of a crack is restricted by the aforementioned helical spring. The aforementioned ignition part is roughly cylindrical in shape; The aforementioned helical spring is roughly cylindrical in shape. Let the inner diameter of the aforementioned gas generating agent containment chamber be R1, the outer diameter of the aforementioned ignition part be R2, the distance from the portion of the aforementioned ignition part containing the aforementioned ignition powder to the aforementioned gas generating agent containment chamber along the axial direction of the aforementioned shell be L1, the distance from the portion of the aforementioned ignition part containing the aforementioned ignition powder to the aforementioned sealed container along the axial direction of the aforementioned shell be L2, and the clearance between the aforementioned ignition part and the surrounding portion that surrounds the aforementioned ignition part in the aforementioned helical spring be C, then the condition 0<C≤(R1-R2)×(L2 / L1) / 2 is satisfied.

2. The gas generator according to claim 1, characterized in that, The aforementioned clearance is less than 1.0 mm.

3. A gas generator, characterized in that, have: A long, cylindrical shell, with one and the other ends closed in the axial direction, and having a peripheral wall portion; The gas generator is disposed inside the aforementioned housing; The igniter has an ignition part that contains an ignition powder for igniting the aforementioned gas generator, and is assembled to one end of the aforementioned housing in such a way that the ignition part protrudes toward the interior of the aforementioned housing. A sealed container, disposed inside the aforementioned housing, defines a gas generating chamber containing the aforementioned gas generating agent, and is subject to heat or pressure generated by the operation of the aforementioned igniter; and A helical spring is clamped between the aforementioned end of the aforementioned housing and the aforementioned sealed container, and is used to fix the aforementioned sealed container inside the aforementioned housing by applying force to the aforementioned other end of the aforementioned housing. The aforementioned ignition part includes the 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, surrounding the aforementioned ignition part without any other components sandwiched between them, so that the opening state of the aforementioned cup body in the event of a crack is restricted by the aforementioned helical spring. The aforementioned ignition part is roughly cylindrical in shape; The aforementioned helical spring is roughly cylindrical in shape. The surrounding portion of the aforementioned helical spring that surrounds the aforementioned ignition part comes into contact with the aforementioned ignition part.

Images