Igniter assembly and gas generator
The igniter assembly's surrounding wall portion disperses impact energy, preventing cracks in the resin fixing portion and ensuring reliable operation by reducing stress concentration.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- DAICEL CORP
- Filing Date
- 2025-12-01
- Publication Date
- 2026-06-18
Smart Images
Figure JP2025041812_18062026_PF_FP_ABST
Abstract
Description
Igniter assembly and gas generator 【0001】 The present invention relates to an igniter assembly and a gas generator. 【0002】 An igniter is used as a starting device such as a gas generator for an airbag or a gas generator for a seat belt retractor, and an electric igniter that operates mainly by an ignition current is widely known. As a structure for attaching the igniter to the gas generator, an igniter assembly that attaches the igniter to the housing via resin is known. 【0003】 In relation to this, in the gas generator shown in Patent Document 1, a structure is disclosed in which a fixed portion formed by a resin molded body for fixing an igniter includes an annular covering portion that adheres to and covers the outer peripheral surface of the squib cup of the igniter. 【0004】 Japanese Patent No. 6243404 【0005】 In the igniter assembly described in Patent Document 1, it is said that by receiving the impact generated during the operation of the igniter by the covering portion, the occurrence of cracks in the fixed portion formed by the resin molded body can be suppressed. However, in the conventional technology, there is still room for improvement from the viewpoint of suppressing the occurrence of cracks in the resin molded body. 【0006】 The technology of the present disclosure has been made in view of the above problems, and its purpose is to provide a technology capable of suppressing the occurrence of cracks in a fixed portion during the operation of an igniter in an igniter assembly that fixes the igniter with a resin-made fixed portion. 【0007】To solve the above problems, the technology of this disclosure employs the following configuration. Specifically, the technology of this disclosure is an igniter assembly comprising: a base portion to which a conductive pin extending downward is attached; a cylindrical peripheral wall portion extending upward from the periphery of the base portion; a lid wall portion closing the upper end of the peripheral wall portion; an igniter housing a gunpowder chamber surrounded by these; a resin fixing portion for fixing the igniter such that at least the lower end of the peripheral wall portion is embedded; and a surrounding wall portion provided integrally with the fixing portion so as to be erected upward from the upper surface of the fixing portion and positioned on the outer periphery of the peripheral wall portion so as to be opposite to the peripheral wall portion, wherein the surrounding wall portion is formed such that the distance from the peripheral wall portion along the transverse direction increases from its lower side to its upper side. 【0008】 In the igniter assembly according to this disclosure, a gap is formed between the surrounding wall portion and the peripheral wall portion, and the width of the gap may gradually increase from the lower side to the upper side. 【0009】 In the igniter assembly according to this disclosure, the surrounding wall portion has a surface facing the peripheral wall portion that functions as a retaining surface for receiving the detached piece of the peripheral wall portion when the igniter is in operation, and the retaining surface may be formed as a curved surface that curves outward in the transverse direction from the lower side to the upper side. 【0010】 In the igniter assembly according to this disclosure, the radius of the curve of the holding surface in the transverse direction outward may be smaller on the upper side than on the lower side. 【0011】 In the igniter assembly according to this disclosure, the vertical length dimension along the curved shape of the retaining surface may be the same as or greater than the height dimension of the peripheral wall portion. 【0012】 In the igniter assembly according to this disclosure, the upper end position of the surrounding wall portion may be the same as or higher than the height of the lid wall portion. 【0013】 In the igniter assembly according to this disclosure, the surrounding wall portion may be configured to sequentially receive the detached pieces of the peripheral wall portion that detach when the igniter is operated, from the lower side to the upper side. 【0014】 In the igniter assembly according to this disclosure, the lower end of the surrounding wall portion may be arranged in contact with the peripheral wall portion. 【0015】 In the igniter assembly according to this disclosure, the surrounding wall portion may be made of resin and integrally molded with the fixing portion. 【0016】 In the igniter assembly according to this disclosure, the surrounding wall portion may be formed as an annular wall body that is continuous in the circumferential direction so as to surround the peripheral wall portion. 【0017】 In the igniter assembly according to this disclosure, the surrounding wall portion may include a plurality of surrounding wall bodies arranged at intervals in the circumferential direction so as to surround the peripheral wall portion. In this case, the distance between adjacent surrounding wall bodies in the circumferential direction may be set to a dimension less than or equal to the length of a single surrounding wall body along the circumferential direction. 【0018】 In the igniter assembly according to this disclosure, the peripheral wall, the lid wall, and the base are all made of metal, the peripheral wall and the lid wall are integrally formed to constitute a storage cup for containing the igniter, the peripheral wall is welded to the base, and the lid wall may have a weak portion that preferentially cracks when the igniter is operated. 【0019】 In the igniter assembly according to this disclosure, the inner surface of the peripheral wall portion, specifically the portion from the upper surface of the base portion to the lid wall portion, is formed as an exposed portion that is exposed to the igniter containment chamber, and at least a part of the exposed portion may be in contact with the igniter. 【0020】 Furthermore, the technology relating to this disclosure may also be a gas generator comprising any of the above-described igniter assemblies, a housing to which the igniter assembly is attached, and a gas source disposed within the housing. 【0021】 The technology disclosed herein provides a method for suppressing crack formation in a resin-based fixing part of an igniter assembly, where the igniter is fixed with a resin fixing part, during operation of the igniter. 【0022】Figure 1 is a cross-sectional view of a gas generator equipped with an igniter assembly according to an embodiment. Figure 2 is a top view of the lid wall portion of the containment cup according to an embodiment. Figure 3 is a vertical cross-sectional view of the area around the containment cup in the igniter assembly according to an embodiment. Figure 4 is a top view of the surrounding wall portion according to an embodiment. Figure 5 is a vertical cross-sectional view illustrating the situation when the containment cup has split open when the igniter is activated in the igniter assembly according to an embodiment. Figure 6 is a top view of the surrounding wall portion according to a modified example. Figure 7 is a diagram illustrating another form of the retaining surface in the surrounding wall. 【0023】 Embodiments of this disclosure will be described below with reference to the drawings. Note that the configurations and combinations thereof in each embodiment are examples only, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of the present invention. This disclosure is not limited by the embodiments, but is limited only by the claims. 【0024】 <Embodiments> Hereinafter, embodiments of the technology disclosed herein will be described in which the technology is applied to an igniter assembly for an airbag gas generator. However, the use of the igniter assembly according to the embodiment is not limited thereto, and it may be applied to a gas generator for a seat belt retractor, for example. Figure 1 is a cross-sectional view of an airbag gas generator (hereinafter simply referred to as a gas generator) 100 equipped with an igniter assembly X1 according to the embodiment. In Figure 1, the state before the igniter indicated by reference numeral 40 is activated is shown. In Figure 1, the gas generator 100 is configured as a so-called single-type gas generator equipped with one igniter. However, the gas generator 100 according to this embodiment may be configured as a multi-type gas generator equipped with multiple igniters. 【0025】As shown in Figure 1, the gas generator 100 comprises a housing 10, an igniter 40, a resin fixing part 50, a cylindrical wall part 60, a lid member 70, a spring member SP1, and a filter F1. The gas generator 100 is configured to inflate the airbag by activating the igniter 40 located inside the housing 10 to burn the first gas generating agent 110 and the second gas generating agent 120 filled inside the housing 10, and releasing the combustion gas, which is the combustion product, to the outside of the housing 10. The components of the gas generator 100 will be described below. 【0026】 [Housing] As shown in Figure 1, the housing 10 is formed in a short cylindrical shape with both ends closed in the axial direction by joining a metal upper shell 20 and a lower shell 30, each formed in a bottomed cylindrical shape, with their open ends facing each other. However, the configuration of the upper shell 20 and lower shell 30 is not limited to this, and known ones can be used as appropriate. Here, the direction along the axial direction of the housing 10 is defined as the "vertical direction" of the gas generator 100, with the upper shell 20 side (i.e., the upper side in Figure 1) being the upper side of the gas generator 100 and the lower shell 30 side (i.e., the lower side in Figure 1) being the lower side of the gas generator 100. The direction perpendicular to the vertical direction is defined as the "transverse direction". In one embodiment shown in Figure 1, since the shape of the housing 10 in the transverse direction is cylindrical, the "transverse direction" may be described as the "radial direction". 【0027】 The upper shell 20 includes, for example, a cylindrical upper section 201, a top plate section 202 that closes the upper end of the upper section 201, and a joint section 203 that extends radially outward from the lower end of the upper section 201. The lower shell 30 includes, for example, a cylindrical lower section 301, a bottom plate section 302 that closes the lower end of the lower section 301, and a joint section 303 that extends radially outward from the upper end of the lower section 301. 【0028】The housing 10 is formed by overlapping the joint portion 203 of the upper shell 20 and the joint portion 303 of the lower shell 30 and joining them together, for example, by laser welding. In addition, the upper cylindrical portion 201 of the upper shell 20 has multiple gas exhaust holes 102 arranged in a line along the circumferential direction, for example, which connect the inside and outside of the housing 10. Before the igniter 40 is activated, the gas exhaust holes 102 are closed, for example, by sealing tape. 【0029】 In the example shown in Figure 1, the lower shell 30 of the housing 10 is provided with a mounting portion 304 to which the igniter 40 is attached. For example, the mounting portion 304 is formed integrally with the bottom plate portion 302. In this case, the metal mounting portion 304 is formed by a part of the housing 10. In the example in Figure 1, the mounting portion 304 is formed in a substantially cylindrical shape by a part of the lower shell 30 protruding upward from the bottom plate portion 302. For example, a mounting hole 304a is formed at the upper end of the mounting portion 304 through which a pair of conductive pins 4 of the igniter 40 are inserted. The igniter assembly X1 according to the embodiment is composed of, for example, an igniter 40, a fixing portion 50, a cylindrical wall portion 60, a lid member 70, a surrounding wall portion 80, etc. 【0030】 [Ignition] The ignition 40 includes a housing cup 1, a base portion 2, an igniter 3, a pair of conductive pins 4 (41, 42), etc. The housing cup 1 is formed in a bottomed cylindrical shape from, for example, a metal material. As an example, the housing cup 1 has a cylindrical peripheral wall portion 11 and a lid wall portion 12. Here, an example is described in which the peripheral wall portion 11 has a cylindrical shape, but it is not limited to this. The lid wall portion 12 closes the upper end side (one end side) of the peripheral wall portion 11. In the example shown in Figure 1, the upper end opening of the peripheral wall portion 11 is closed by the lid wall portion 12. Here, the housing cup 1 is constructed by the peripheral wall portion 11 and the lid wall portion 12 being formed integrally (for example, formed from a single member), but the peripheral wall portion 11 and the lid wall portion 12 may be constructed as separate members. 【0031】The materials forming the storage cup 1 (peripheral wall portion 11 and lid wall portion 12) and the base portion 2 are not particularly limited, but as an example, they may be made of metal. The metal material for forming them is not particularly limited, but examples include stainless steel, aluminum, iron, etc. The base portion 2 is, as an example, a columnar member formed in a cylindrical shape and holds a pair of conductive pins 4 (41, 42). The pair of conductive pins 4 (41, 42) extend downward from the base portion 2. Connectors for supplying power from an external power source are connected to the pair of conductive pins 4 (41, 42), for example. 【0032】 The peripheral wall portion 11 of the storage cup 1 is attached to the periphery (side surface) of the base portion 2. For example, the storage cup 1 (peripheral wall portion 11 and lid wall portion 12) and the base portion 2 are all made of the same metal material. For example, the peripheral wall portion 11 is integrally joined to the periphery (side surface) of the base portion 2 by welding. In the igniter 40 constructed in this way, an igniter storage chamber 401 is formed inside the storage cup 1, that is, in the space defined by the inner surfaces of the peripheral wall portion 11 and lid wall portion 12 and the upper surface of the base portion 2. The igniter 3 is stored (filled) in the igniter storage chamber 401. 【0033】 The igniter 40 is operated, for example, by power supplied to each conductive pin 4 via a connector, and ignites the igniter 3 contained in the igniter chamber 401. The combustion pressure of the igniter 3 causes the containment cup 1 (mainly the lid wall portion 12) to rupture, releasing the combustion products of the igniter 3 to the outside of the containment cup 1. 【0034】[Fixing part] The fixing part 50 is a member for fixing the igniter 40 and is made of a resin material. The fixing part 50 is interposed between the igniter 40 and the mounting part 304 in the housing 10, and fixes the igniter 40 to the mounting part 304. In the example shown in Figure 1, the fixing part 50 holds the igniter 40 such that the housing cup 1 and the base part 2 are located inside the housing 10, and a pair of conductive pins 4 are inserted through the mounting holes 304a with their tips located outside the housing 10. The fixing part 50 holds the igniter 40 such that at least the lower end of the peripheral wall 11 of the housing cup 1 is embedded. In the example shown in Figure 1, the lower end of the base part 2 and the peripheral wall 11 are embedded in the fixing part 50. The mounting hole 304a in the mounting part 304 is closed by, for example, the fixing part 50, thereby maintaining airtightness inside the housing 10. 【0035】 [Cylindrical Wall] In the example shown in Figure 1, the cylindrical wall 60 is a member arranged to surround the peripheral wall 11 of the storage cup 1, and is formed of, for example, a resin material. The cylindrical wall 60 extends upward from the upper surface of the fixing part 50, for example. The cylindrical wall 60 also has a cylindrical shape, for example. Inside the cylindrical wall 60, there is a discharge space 601, which is a space from which the combustion products of the igniter 3 are released. The discharge space 601 is filled with, for example, a first gas generating agent 110 that burns when the igniter 40 is activated. The first gas generating agent 110 is ignited by, for example, the combustion products of the igniter 3 released when the igniter 40 is activated, and generates combustion gas. The fixing part 50 and the cylindrical wall 60 are formed of, for example, a single member and are continuous with each other. Furthermore, the cylindrical wall portion 60 has, for example, multiple communication holes 602 that connect the inside and outside of the discharge space 601, arranged in a line along the circumferential direction. 【0036】The fixing portion 50 and the cylindrical wall portion 60 are integrally formed in the manufacturing process of the igniter assembly X1, for example, by injection molding of a resin material. The resin material used to form the fixing portion 50 and the cylindrical wall portion 60 may be a resin material that has excellent heat resistance, durability, corrosion resistance, etc. after curing. Examples of such resin materials include thermoplastic resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin, polypropylene sulfide resin, and polypropylene oxide resin, and thermosetting resins such as epoxy resin. 【0037】 [Cover Member] In the example shown in Figure 1, the cover member 70 is fitted into the cylindrical wall portion 60 through an opening formed at the upper end of the cylindrical wall portion 60, thereby defining the discharge space 601 together with the cylindrical wall portion 60. For example, before the igniter 40 is activated, the cover member 70 covers the communication hole 602 from the inside of the cylindrical wall portion 60, thereby closing the communication hole 602. 【0038】 [Spring Member] The spring member SP1 is an elastic member and is interposed, for example, between the lid member 70 and the top plate portion 202 of the upper shell 20. The spring member SP1, for example, presses the lid member 70 downward (i.e., toward the release space 601) by its biasing force. This prevents the lid member 70 from coming out of the cylindrical wall portion 60 and prevents rattling of the first gas generating agent 110 filled in the release space 601. 【0039】[Filter] As shown in Figure 1, the filter F1 is formed in a cylindrical shape, with its upper end supported by the top plate portion 202 of the upper shell 20 and its lower end supported by the bottom plate portion 302 of the lower shell 30, and is positioned between the igniter assembly X1 and the gas discharge hole 102. As a result, a combustion chamber 101 is formed between the igniter assembly X1 and the filter F1. The combustion chamber 101 is filled with, for example, a second gas generating agent 120 that burns when the igniter 40 is activated. The second gas generating agent 120 is ignited by the combustion gas of the first gas generating agent 110 that burns when the igniter 40 is activated, for example, and generates combustion gas. The filter F1 is configured to allow the combustion gas to pass through, and the combustion gas in the combustion chamber 101 is cooled as it passes through the filter F1. At this time, the filter F1 filters the combustion gas by capturing the combustion residue of the combustion gas. 【0040】 [Gas Generating Agent] For the second gas generating agent 120, for example, a gas generating agent with a relatively low combustion temperature may be used. The combustion temperature of the second gas generating agent 120 may be in the range of 1000 to 1700°C, for example, and a single-hole cylindrical form consisting of guanidine nitrate (41% by weight), basic copper nitrate (49% by weight), and a binder or additive may be used. Furthermore, for the first gas generating agent 110, for example, one with a higher combustion temperature than the second gas generating agent 120 may be used. However, the first gas generating agent 110 and the second gas generating agent 120 are not limited to the above. Also, the first gas generating agent 110 and the second gas generating agent 120 may be gas generating agents of the same type, shape, and dimensions, or they may be gas generating agents of different types, shapes, and dimensions. The first gas generating agent 110 and the second gas generating agent 120 that generate gas by combustion are examples of "gas sources" according to this disclosure. 【0041】[Basic Operation] Next, the basic operation of the gas generator 100 will be described. For example, when the gas generator 100 is assembled in an automobile, it is in a state where power can be supplied to the igniter 40 via a connector. In this state, for example, when a sensor (not shown) mounted on the automobile senses an impact, power from an external power source is supplied to the pair of conductive pins 4 via the connector, causing the igniter 40 to operate and the ignition charge 3 in the ignition charge housing 401 to burn. 【0042】 As the pressure in the ignition charge housing 401 increases due to the combustion of the ignition charge 3, the housing cup 1 cracks, and high-temperature flames, gases, etc., which are combustion products of the ignition charge 3, are released into the discharge space 601. As a result, the first gas generating agent 110 in the discharge space 601 ignites. Due to the combustion gas pressure (hereinafter also referred to as the combustion pressure) of the first gas generating agent 110, the lid member 70 slides upward (i.e., toward the open end side of the cylindrical wall portion 60) against the biasing force of the spring member SP1. Thereby, the closed state of the communication hole 602 by the lid member 70 is released, and the combustion gas of the first gas generating agent 110 is discharged from the communication hole 602 into the combustion chamber 101. 【0043】 The combustion gas of the first gas generating agent 110 discharged from the communication hole 602 into the combustion chamber 101 ignites the second gas generating agent 120, generating the combustion gas of the second gas generating agent 120 in the combustion chamber 101. The combustion gas in the combustion chamber 101 is cooled and filtered by the filter F1, then breaks the sealing tape that has been blocking the gas discharge hole 102, and is discharged from the gas discharge hole 102 to the outside of the housing 10. As a result, the airbag inflates and the occupant is protected from the impact. 【0044】 Hereinafter, the details of the igniter assembly X1 according to the present embodiment will be exemplarily described. 【0045】[Lid Wall] Figure 2 is a top view of the lid wall 12 of the housing cup 1 in the igniter assembly X1 according to the embodiment. Figure 2 shows the state before the igniter 40 is activated. The lid wall 12 shown in Figure 2 has a weak portion 121 that preferentially ruptures when the igniter 40 is activated. The weak portion 121 is formed as, for example, a part of the lid wall 12 that is thinner than other areas. For example, the weak portion 121 is formed by a plurality of grooves that extend radially from the center C1 of the lid wall 12. The plurality of grooves forming the weak portion 121 are formed on the outer surface (top surface) S1 side of the lid wall 12, and the part where the grooves are formed is thinner than other parts, so that the grooves can preferentially rupture when the igniter 40 is activated. The center C1 of the lid wall 12 is located, for example, on the central axis CA1 of the peripheral wall 11. Furthermore, the above-described embodiment of the weak portion 121 in the lid wall portion 12 is just one example. Also, the weak portion 121 in the lid wall portion 12 can be any element. 【0046】 [Enclosing Wall] The igniter assembly X1 according to this embodiment includes an enclosing wall 80. Figure 3 is a diagram showing a vertical cross-section around the housing cup 1 in the igniter assembly X1 according to this embodiment. Figure 3 shows the state before the igniter 40 is activated. The details of the enclosing wall 80 will be described below with reference to Figure 3. In the figure, reference numeral 111 denotes the upper end of the peripheral wall 11, 112 denotes the lower end, and 113 denotes the base. As shown in Figure 3, the lower end 112 side of the peripheral wall 11 in the housing cup 1 is fixed to the base 2 by a method such as welding, and is further embedded in the fixing part 50. The base part 113 of the peripheral wall 11 is the part of the peripheral wall 11 that is located at the boundary between the area embedded in the fixing part 50 and the area that is not embedded. The base part 113 of the peripheral wall 11 is located at exactly the same height as the upper surface 51 of the fixing part 50. 【0047】When the igniter 40 operates, the lid wall portion 12 will preferentially crack. However, since the interior of the igniter accommodation chamber 401 becomes high pressure due to the combustion of the ignition charge 3, it is also assumed that the peripheral wall portion 11 will crack from the upper end 111 side towards the root portion 113 side. When the surrounding wall portion 80 does not exist, the peripheral wall portion 11 is deformed so as to open towards the outside in the transverse direction (radial direction) starting from the upper end 111. At that time, since the lower end 112 side of the peripheral wall portion 11 is welded to the base portion 2 and fixed in a state of being embedded in the fixing portion 50, stress caused by the deformation of the peripheral wall portion 11 concentrates on the peripheral portion of the fixing portion 50 where the lower end 112 side of the peripheral wall portion 11 is embedded, and there is a risk that cracks will occur in the resin-made fixing portion 50. And if cracks occur in the fixing portion 50, it becomes easy for gas to leak from the crack generation location, so there is concern that it will affect the operation of the gas generator 100. 【0048】 Therefore, in the igniter assembly X1 according to the present embodiment, a surrounding wall portion 80 is disposed on the upper surface of the fixing portion 50 so as to surround the peripheral wall portion 11 of the housing cup 1 from the outer peripheral side, reducing stress concentration caused by the deformation of the peripheral wall portion 11 and suppressing the occurrence of cracks in the fixing portion 50. 【0049】 In the example shown in FIG. 3, the surrounding wall portion 80 is provided integrally with the fixing portion 50 so as to stand upright upward from the upper surface 51 of the fixing portion 50. The surrounding wall portion 80 may be made of, for example, resin. In this case, in the manufacturing process of the igniter assembly X1, for example, it may be integrally molded with the fixing portion 50, the cylindrical wall portion 60, etc. by injection molding of a resin material. However, the material of the surrounding wall portion 80 is not particularly limited. Also, in the manufacturing process of the igniter assembly X1, the surrounding wall portion 80 may be prepared as a separate member from the fixing portion 50, and the surrounding wall portion 80 may be fixed to the upper surface 51 of the fixing portion 50 by a known method. 【0050】Figure 4 is a top view of the surrounding wall portion 80 according to the embodiment. In Figure 4, the surrounding wall portion 80 is formed as an annular wall (for example, a cylindrical wall) that is continuous in the circumferential direction so as to surround the peripheral wall portion 11 of the receiving cup 1. The surrounding wall portion 80 is positioned on the outer periphery side of the peripheral wall portion 11 so as to face the peripheral wall portion 11, and is formed such that the distance from the peripheral wall portion 11 along the transverse direction (radial direction) of the igniter assembly X1 gradually increases from the lower side to the upper side. 【0051】 In Figure 3, reference numeral 81 denotes the holding surface of the surrounding wall portion 80. The holding surface 81 of the surrounding wall portion 80 is the inner circumferential surface of the surrounding wall portion 80 and is positioned opposite to the circumferential wall portion 11. In a longitudinal cross-sectional view as shown in Figure 3, the holding surface 81 of the surrounding wall portion 80 has a continuously curved surface. Reference numeral 82 denotes the outer circumferential surface of the surrounding wall portion 80 and is the surface located on the opposite side from the holding surface 81. The outer circumferential surface 82 of the surrounding wall portion 80 may be formed, for example, as a plane that extends in a planar manner along the vertical direction. In the example shown in Figure 3, the outer circumferential surface 82 of the surrounding wall portion 80 is integrally connected along the inner circumferential surface 60A of the cylindrical wall portion 60, but this is not limited to the example. The shape of the outer circumferential surface 82 of the surrounding wall portion 80 is not particularly limited, and a gap may be provided between the outer circumferential surface 82 of the surrounding wall portion 80 and the inner circumferential surface 60A of the cylindrical wall portion 60. 【0052】 Furthermore, reference numeral 83 denotes the lower end of the surrounding wall portion 80, and reference numeral 84 denotes the upper end of the surrounding wall portion 80. The lower end portion 83 of the surrounding wall portion 80 is connected to the upper surface 51 of the fixing portion 50. In the example shown in Figure 3, the thickness of the surrounding wall portion 80 in the transverse direction (radial direction) gradually decreases from the lower end portion 83 side to the upper end portion 84 side. 【0053】The surrounding wall portion 80, configured as described above, is formed such that the distance d1 from the peripheral wall portion 11 along the transverse direction (radial direction) of the igniter assembly X1 gradually increases from the lower side to the upper side. A gap G is formed between the surrounding wall portion 80 and the peripheral wall portion 11, and the width w1 of the gap G gradually increases from the lower side to the upper side. The holding surface 81 of the surrounding wall portion 80 functions as a surface that receives the splitting piece of the peripheral wall portion 11 when the igniter 40 is operated. The width w1 of the gap G is the dimension along the transverse direction (radial direction) of the gap G, and is substantially equal to the distance d1 described above. 【0054】 [Function and Effects] Figure 5 is a longitudinal cross-sectional view illustrating the situation in the igniter assembly X1 according to the embodiment, where the housing cup 1 has split open when the igniter 40 is activated. Figure 5 simulates the situation in which, after the lid wall portion 12 splits open due to the operation of the igniter 40, the split in the lid wall portion 12 extends to the peripheral wall portion 11, and the split piece 11A of the split peripheral wall portion 11 (hereinafter referred to as "peripheral wall split piece") is received by the holding surface 81 of the surrounding wall portion 80. The igniter assembly X1 is configured such that even when the peripheral wall portion 11 deforms radially outward due to the combustion pressure of the igniter 3 contained in the housing cup 1, the peripheral wall split piece 11A is received by the holding surface 81 of the surrounding wall portion 80. Note that the cylindrical wall portion 60 and the like are omitted from the illustration in Figure 5. 【0055】 As explained in Figure 3, the surrounding wall portion 80 is formed such that, before the igniter 40 is activated, the distance d1 from the peripheral wall portion 11 along the transverse direction (radial direction) of the igniter assembly X1 gradually increases from the lower side to the upper side. In other words, before the igniter 40 is activated, the width w1 of the gap G formed between the peripheral wall portion 11 and the surrounding wall portion 80 gradually increases from the lower side of the holding surface 81 (for example, the lower end portion 83 side of the surrounding wall portion 80) to the upper side (for example, the upper end portion 84 side of the surrounding wall portion 80). 【0056】According to this, as shown in Figure 5, the orientation of the peripheral wall cracking piece 11A received by the holding surface 81 of the surrounding wall portion 80 is such that it is curved outward in the transverse (radial) direction along the holding surface 81. By the holding surface 81 receiving the peripheral wall cracking piece 11A in this orientation, the impact from the peripheral wall cracking piece 11A can be dispersed not only in the transverse (radial) direction but also in the downward direction. In other words, by distributing a portion of the impact energy acting on the surrounding wall portion 80 from the peripheral wall cracking piece 11A as a downward force pushing the surrounding wall portion 80, the force acting outward in the transverse (radial) direction on the surrounding wall portion 80 can be reduced. As a result, the outward force in the transverse (radial) direction acting on the portion of the fixing portion 50 in which the peripheral wall portion 11 is embedded is reduced, making it easier to suppress the occurrence of cracks in the fixing portion 50. 【0057】 As described above, the igniter assembly X1 according to this embodiment can suppress the occurrence of unintended cracks in the fixing part 50 that would cause malfunctions in the operation of the gas generator 100. For example, it can suppress the occurrence of malfunctions during operation such as the igniter 40 lifting up, resulting in an unintended combustion state of the first gas generating agent 110 or the second gas generating agent 120, gas leaking to the outside of the gas generator 100, or flames being ejected. In other words, the technology of this disclosure can provide an igniter assembly X1 that can maintain the integrity of the igniter 40 during operation. 【0058】Here, P1, P2, P3, ... shown in Figure 5 are illustrative contact points where the peripheral wall rupture piece 11A abuts against the holding surface 81 of the surrounding wall 80 when the peripheral wall 11 ruptures. The surrounding wall 80 is formed such that the distance d1 (see Figure 3) from the peripheral wall 11 gradually increases from the lower side to the upper side before the ignition device 40 is activated. Therefore, for example, the peripheral wall rupture piece 11A collides with the holding surface 81 sequentially from the lower side to the upper side in the order of contact points P1 → P2 → P3. Thus, the holding surface 81 of the surrounding wall 80 may be configured to sequentially receive the peripheral wall rupture piece 11A that ruptures when the ignition device 40 is activated, from the lower side to the upper side. By receiving the peripheral wall splitting piece 11A while shifting the contact point of the peripheral wall splitting piece 11A with respect to the holding surface 81 in the height direction (up and down direction), the impact when the peripheral wall splitting piece 11A collides can be mitigated. 【0059】Furthermore, the radius of curvature of the holding surface 81 of the surrounding wall portion 80, which curves outward in the transverse (radial) direction of the igniter assembly X1, may be configured such that the upper side is relatively smaller than the lower side. For example, the radius of curvature of the holding surface 81 of the surrounding wall portion 80 may change continuously (gradually) towards the upper end 84, starting from the lower end 83. As an example, the shape of such a holding surface 81 may be formed to draw a clothoid curve. A clothoid curve is a type of transition curve and is sometimes called an Euler spiral or Cornu spiral. By setting the radius of curvature of the holding surface 81 as described above, the degree of curvature of the upper side (upper end 84 side) of the holding surface 81, which receives the upper end 111 side of the peripheral wall portion 11 that becomes the starting point of the crack when the peripheral wall portion 11 cracks, can be increased. Here, the amount of deformation is particularly large on the upper end 111 side, which becomes the starting point of the crack when the peripheral wall portion 11 cracks. Therefore, by increasing the degree of curvature on the upper side (upper end 84 side) of the holding surface 81, when the peripheral wall portion 11 cracks, the portion of the peripheral wall crack piece 11A on the upper end 111 side collides with the holding surface 81 in a horizontal position (closer to horizontal), and the collision energy is more easily dispersed downward. In other words, by using the collision energy of the peripheral wall crack piece 11A with respect to the holding surface 81 as energy to push the surrounding wall portion 80 downward, the force acting radially outward on the fixing portion 50 can be further reduced. As a result, the occurrence of cracks in the fixing portion 50 can be more easily suppressed. Also, as shown in Figure 5, the tilt angle of the peripheral wall crack piece 11A in the transverse direction (radial direction) can be limited by the surrounding wall portion 80 (holding surface 81), so for example, it is possible to give directionality to the combustion products generated from the ignition charge 3. As a result, the energy generated by the combustion of the ignition charge 3 can be concentrated and supplied to the first gas generating agent 110. Furthermore, if such a surrounding wall portion 80 is not present, it is expected that the peripheral wall fracture piece 11A will bend significantly at the base portion 113, and in some cases, the peripheral wall fracture piece 11A may be cut at the base portion 113 (becoming fragments that are carried downstream), which could affect the gas flow. 【0060】Furthermore, the retaining surface 81 of the surrounding wall portion 80 may have a vertical length dimension L1 along its curved shape that is the same as or greater than the height dimension H1 of the peripheral wall portion 11 before the igniter 40 is activated. Also, before the igniter 40 is activated, the position of the upper end portion 84 of the surrounding wall portion 80 (retaining surface 81) may be positioned at the same height as or higher than the height of the lid wall portion 12. With this configuration, when the peripheral wall portion 11 splits open due to the activation of the igniter 40, the entire section of the peripheral wall portion 11 (peripheral wall splitting piece 11A) from the base portion 113 to the upper end 111 can be received by the retaining surface 81. As a result, for example, there is no case where a part of the peripheral wall splitting piece 11A is not received by the retaining surface 81. Therefore, for example, the impact when the peripheral wall splitting piece 11A collides with the retaining surface 81 can be more effectively mitigated. Furthermore, it is possible to suppress the tearing of parts of the peripheral wall fracture piece 11A that are not received by the holding surface 81 due to the impact when the peripheral wall fracture piece 11A collides with the holding surface 81. 【0061】 Furthermore, the igniter assembly X1 according to this embodiment may be positioned such that, for example, as shown in Figure 3, the lower end portion 83 of the surrounding wall portion 80 is in contact with the peripheral wall portion 11 before the igniter 40 is activated. This allows the impact energy to be consumed as described above by constraining the root portion 113 and its vicinity in the peripheral wall portion 11 with the surrounding wall portion 80, while allowing deformation of the igniter assembly X1 toward the transverse (radial) outward direction in the region above that point. Of course, the igniter assembly X1 is not limited to this configuration. That is, before the igniter 40 is activated, the lower end portion 83 of the surrounding wall portion 80 may be positioned spaced apart from the peripheral wall portion 11. 【0062】 Furthermore, in the igniter assembly X1 according to this embodiment, for example, as shown in Figure 3, the portion of the inner surface of the peripheral wall portion 11 from the upper surface of the base portion 2 to the lid wall portion 12 is formed as an exposed portion 114 that is exposed to the igniter containment chamber 401, and at least a part of the exposed portion 114 may be in contact with the igniter 3. 【0063】Furthermore, although the example shown in Figure 4 describes a configuration in which the surrounding wall portion 80 is formed as a continuous annular wall (cylindrical wall) in the circumferential direction, the method is not limited to this. For example, the surrounding wall portion 80A shown in Figure 6 may be composed of a plurality of surrounding wall portions 800 arranged at intervals in the circumferential direction to surround the circumferential wall portion 11. Figure 6 is a top view of the surrounding wall portion 80A. Note that the surrounding wall portion 80A may be the same as, for example, the surrounding wall portion 80 shown in Figure 3. Even with a plurality of surrounding wall portions 800 arranged at intervals to surround the circumferential wall portion 11, similar to the surrounding wall portion 80 described above, the cracked circumferential wall fragments 11A that break when the igniter 40 is operated can be received and the impact mitigated, thereby effectively suppressing the occurrence of cracks in the fixing portion 50. Note that the number of the plurality of surrounding wall portions 800 constituting the surrounding wall portion 80A is not particularly limited. 【0064】 In the embodiment shown in Figure 6, the distance L2 between adjacent surrounding wall bodies 800 in the circumferential direction may be set to a dimension less than or equal to the length L3 along the circumferential direction of a single surrounding wall body 800. This embodiment prevents the distance L2 between adjacent surrounding wall bodies 800 in the circumferential direction from becoming excessively large, and allows the surrounding wall bodies 800 to suitably receive the ruptured circumferential wall fragments 11A that rupture when the igniter 40 is activated. In particular, a weak portion 121 may be formed in the circumferential wall portion 11 of the containment cup 1 so that the ruptured circumferential wall fragments 11A can be received by each surrounding wall body 800, thereby enabling the rupture of the containment cup 1 to be reproducible. For example, the weak portion 121 (groove) of the lid wall portion 12 shown in Figure 2 may be extended transversely (radially) to the outer circumference of the lid wall portion 12, and the weak portion 121 (groove) may be formed continuously from the lid wall portion 12 to the circumferential wall portion 11 so that it extends from the upper end 111 to the lower end 112 of the circumferential wall portion 11. Of course, the manner in which the weak portion 121 is formed is not limited to the above example. For example, the weak portion 121 (groove) formed on the lid wall portion 12 and the weak portion 121 (groove) formed on the circumferential wall portion 11 do not have to be continuous. The weak portion 121 (groove) formed on the circumferential wall portion 11 may be positioned, for example, between adjacent surrounding wall bodies 800 in the circumferential direction. 【0065】Furthermore, the retaining surface 81 in each of the surrounding wall bodies 800 constituting the surrounding wall portion 80 or the surrounding wall portion 80A described above is not limited to a true curved surface which is a continuous smooth curved surface as shown in Figure 3, etc., but may be a pseudo-curved surface formed by connecting multiple planes, for example, as shown in Figure 7. Figure 7 is a diagram illustrating another form of the retaining surface 81 in the surrounding wall portion 80 (or surrounding wall body 800). In this way, even if the retaining surface 81 is formed by a pseudo-curved surface formed by connecting multiple planes, the same effects as in the above embodiment can be achieved. In the example shown in Figure 7, the retaining surface 81 formed by the pseudo-curved surface is curved outward in the transverse direction (radial direction) of the igniter assembly X1 as it moves from the lower side to the upper side. 【0066】 <Other> The embodiments of the ignition device assembly and gas generator equipped therewith according to this disclosure have been described above. However, each embodiment disclosed herein can be combined with any other features disclosed herein. In addition, although the above embodiments were described using the application of the ignition device assembly of this disclosure to a single-type gas generator equipped with only one ignition device as an example, the ignition device assembly of this disclosure may also be applied to gas generators equipped with multiple ignition devices. Furthermore, although an example of application to a so-called pyro-type gas generator was illustrated in Figure 1, etc., the ignition device assembly of this disclosure may of course also be applied to a filled-gas type gas generator in which only gas is pressurized and filled in the housing, or to a hybrid type gas generator that combines the pyro-type and filled-gas type. 【0067】 Furthermore, although the above embodiment described the application of the igniter assembly to a gas generator for an airbag or seat belt retractor as an example, it may also be applied to other gas generators. For example, it can be used in gas generators for airbag devices worn on the human body, airbag devices mounted on drones, and gas generators for inflating flotation devices such as lifebuoys. In addition, a housing other than the housing of the gas generator may be used as the object to which the igniter assembly is attached. 【0068】1... Storage cup 2... Base 3... Ignition charge 11... Peripheral wall 12... Lid wall 10... Housing 40... Ignition device 50... Fixing part 60... Cylindrical wall 80... Enclosing wall 81... Holding surface 100... Gas generator X1... Ignition device assembly
Claims
1. An igniter assembly comprising: a base portion to which a conductive pin extending downward is attached; a cylindrical peripheral wall portion extending upward from the periphery of the base portion; a lid wall portion closing the upper end of the peripheral wall portion; an igniter having an igniter housing chamber surrounded by these; a resin fixing portion for fixing the igniter such that at least the lower end of the peripheral wall portion is embedded; and a surrounding wall portion provided integrally with the fixing portion so as to be erected upward from the upper surface of the fixing portion and positioned on the outer periphery of the peripheral wall portion so as to be opposite to the peripheral wall portion, wherein the surrounding wall portion is formed such that the distance from the peripheral wall portion along the transverse direction increases from its lower side to its upper side.
2. The igniter assembly according to claim 1, wherein a gap is formed between the surrounding wall portion and the peripheral wall portion, and the width of the gap gradually increases from the lower side to the upper side.
3. The surrounding wall portion has a surface facing the peripheral wall portion that functions as a retaining surface for receiving the detached piece of the peripheral wall portion when the igniter is operated, and the retaining surface is formed as a curved surface that curves outward in the transverse direction from the lower side to the upper side, according to claim 1 or 2.
4. The igniter assembly according to claim 3, wherein the radius of the curve of the retaining surface in the transverse direction outward is smaller on the upper side than on the lower side.
5. The igniter assembly according to claim 4, wherein the vertical length dimension along the curved shape of the retaining surface is equal to or greater than the height dimension of the peripheral wall portion.
6. The igniter assembly according to claim 1 or 2, wherein the upper end position of the surrounding wall portion is the same as or higher than the height of the lid wall portion.
7. The igniter assembly according to claim 1 or 2, wherein the surrounding wall portion is configured to sequentially receive the detached pieces of the peripheral wall portion that detach when the igniter is operated, from the lower side to the upper side.
8. The igniter assembly according to claim 1 or 2, wherein the lower end of the surrounding wall portion is positioned in contact with the peripheral wall portion.
9. The igniter assembly according to claim 1 or 2, wherein the surrounding wall portion is made of resin and integrally molded with the fixing portion.
10. The igniter assembly according to claim 1 or 2, wherein the surrounding wall portion is formed as an annular wall body that is continuous in the circumferential direction so as to surround the peripheral wall portion.
11. The igniter assembly according to claim 1 or 2, wherein the surrounding wall portion includes a plurality of surrounding wall bodies arranged at intervals in the circumferential direction so as to surround the peripheral wall portion.
12. The igniter assembly according to claim 11, wherein the spacing between adjacent surrounding wall bodies in the circumferential direction is set to a dimension less than or equal to the length of a single surrounding wall body along the circumferential direction.
13. The igniter assembly according to claim 1 or 2, wherein the peripheral wall, the lid wall, and the base are all made of metal, the peripheral wall and the lid wall are integrally formed to constitute a storage cup for containing the igniter, the peripheral wall is welded to the base, and the lid wall has a weak portion that preferentially cracks when the igniter is operated.
14. The igniter assembly according to claim 1 or 2, wherein the inner surface of the peripheral wall portion, from the upper surface of the base portion to the lid wall portion, is formed as an exposed portion that is exposed to the igniter containment chamber, and at least a part of the exposed portion is in contact with the igniter.
15. A gas generator comprising: an igniter assembly according to claim 1 or 2; a housing to which the igniter assembly is attached; and a gas source disposed within the housing.