Igniter assembly and gas generator

Abstract

The ignition device assembly includes: an ignition device including a metal container and a booster, the metal container having a cylindrical wall portion and a lid wall portion closing one end portion of the wall portion, the booster being filled in a containing space defined by the wall portion and the lid wall portion, and the lid wall portion being cracked when the ignition device works, so that combustion products of the booster are emitted to the outside of the container; and a resin cylindrical wall portion formed in a cylindrical shape to surround the wall portion, and forming an emission space on the inside for the combustion products of the booster to be emitted, the lid wall portion including: an annular outer peripheral area portion connected to one end portion of the wall portion; and a central area portion located at the inside of the wall portion in the radial direction than the outer peripheral area portion, the outer peripheral area portion being formed as a thicker wall than the central area portion.

Description

Technical Field

[0001] The present invention relates to an igniter assembly and a gas generator having the igniter assembly. Background Technology

[0002] Igniters are widely known as starting devices for gas generators in airbags, gas generators in seat belt retractors, etc., and they mainly operate by means of ignition current. As a structure for assembling an igniter into a gas generator, an igniter assembly is known in which the igniter is assembled to a cylindrical component housed in a housing via resin.

[0003] Relatedly, in the gas generator shown in Patent Document 1, a cylindrical mounting portion for assembling an igniter is formed at the center of the base plate of the housing. The igniter is fixed to the mounting portion by resin disposed between the igniter and the mounting portion. This resin also forms a peripheral wall portion surrounding the igniter, and the space inside the peripheral wall portion is filled with a gas generating agent that burns during the operation of the igniter. A space is formed at the other end of the mounting portion for inserting a connector for supplying current to the igniter.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: US Patent No. 7,540,241

[0007] Patent Document 2: US Patent No. 5005486 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] When the igniter operates, the metal container holding the detonator cracks, releasing a flame. In structures where the igniter is surrounded by a resin-lined peripheral wall, when the cracked container comes into contact with the peripheral wall during ignition, the load acting on the peripheral wall can cause deformation, potentially leading to cracks or breakage. In such cases, the cracks or breakage may result in insufficient igniter retention or compromised sealing as a gas generator.

[0010] The technology disclosed herein was made in view of the above-mentioned problems, and its object is to provide a technology that can suppress the large load on the peripheral wall caused by the cracked cup wall when the igniter is working in an igniter assembly with a structure in which the igniter is surrounded by a resin peripheral wall.

[0011] Technical solution

[0012] To address the aforementioned problems, the present disclosure employs the following configuration. Specifically, the present disclosure provides an igniter assembly comprising: an igniter including a metal container and an initiating explosive, the metal container having a cylindrical peripheral wall portion and a cover wall portion blocking one end of the peripheral wall portion, the initiating explosive being filled in a receiving space defined by the peripheral wall portion and the cover wall portion, and, when the igniter is activated, the cover wall portion cracks, thereby releasing the combustion products of the initiating explosive to the outside of the container; and a resin cylindrical wall portion formed in a cylindrical shape surrounding the peripheral wall portion, forming an inner release space for releasing the combustion products of the initiating explosive, the cover wall portion including: an annular outer peripheral region portion disposed radially inward of the peripheral wall portion; and a central region portion disposed radially inward of the outer peripheral region portion, the outer peripheral region portion being formed as a wall thicker than the central region portion.

[0013] During ignition, due to the combustion pressure of the initiating explosive, the cover wall deforms by opening towards the release space, starting from one end of the peripheral wall. In the ignition assembly of this disclosure, the outer peripheral region is formed as a wall thicker than the central region, thus exhibiting higher rigidity and being less prone to deformation. Consequently, since the outer peripheral region connected to the peripheral wall is less prone to deformation, the large-scale opening of the cover wall is suppressed. Therefore, strong contact between the cracked cover wall and the cylindrical wall is suppressed. That is, the cracked cover wall will not contact the cylindrical wall, or even if it does, it will not generate a large load. As a result, the ignition assembly of this disclosure can suppress large loads exerted on the cylindrical wall by the cracked cover wall during ignition operation, preventing cracks, damage, and other adverse conditions in the cylindrical wall.

[0014] Furthermore, in the aforementioned igniter assembly, the outer peripheral region and the central region may be connected such that the discharge surface facing the discharge space in the cover wall is recessed in the central region.

[0015] Furthermore, in the aforementioned igniter assembly, multiple grooves extending radially from the center of the central region may be formed in the central region.

[0016] Furthermore, in the aforementioned igniter assembly, the radial distance from the center of the central region to the outer peripheral region may be less than 1 / 2 of the radial distance from the center to the cylindrical wall.

[0017] Furthermore, in the aforementioned igniter assembly, the release space may also be filled with a first gas generator ignited by the combustion products of the initiating explosive.

[0018] Furthermore, the technology disclosed herein can also be a gas generator comprising: the aforementioned igniter assembly; a housing on which the igniter assembly is mounted; a combustion chamber formed inside the housing and filled with a second gas generating agent that is burned by the operation of the igniter; and a gas exhaust port formed in the housing, communicating the combustion chamber with the external space of the housing.

[0019] It should be noted that the gas generating agent disclosed herein includes a gas generating agent for generating combustion gas for inflating the gasbag and a ignition agent for igniting the gas generating agent.

[0020] Invention Effects

[0021] According to this disclosure, in an igniter assembly with a structure in which the igniter is surrounded by a resin peripheral wall, it is possible to suppress the large load exerted on the peripheral wall by the cracked cup body when the igniter is in operation. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of a gas generator for a gas bag equipped with the igniter assembly of Embodiment 1.

[0023] Figure 2 This is a cross-sectional view of the igniter assembly according to Embodiment 1.

[0024] Figure 3 This is a cross-sectional view showing the state near the cup before the igniter operates in the igniter assembly of Embodiment 1.

[0025] Figure 4 This is a top view showing the state of the cup cover wall in the igniter assembly of Embodiment 1 before the igniter is activated.

[0026] Figure 5 This is a cross-sectional view showing the state after the lid wall of the cup body cracks due to the igniter working in the igniter assembly of Embodiment 1.

[0027] Figure 6 This is a cross-sectional view showing the state near the cup before the igniter operates in the igniter assembly of a modified embodiment 1.

[0028] Figure 7 This is a cross-sectional view of the igniter assembly according to Embodiment 2. Detailed Implementation

[0029] The embodiments of this disclosure will now be described with reference to the accompanying drawings. It should be noted that each embodiment and its combination are merely examples, and appropriate additions, omissions, substitutions, and other modifications to the configuration can be made without departing from the spirit of the invention. This disclosure is not limited to the embodiments, but only to the claims.

[0030] <Implementation Method 1>

[0031] Hereinafter, as Embodiment 1, a scheme for applying the technology of this disclosure to an igniter assembly for an airbag gas generator will be described. However, the application of the igniter assembly of Embodiment 1 is not limited to this; for example, it can also be applied to a gas generator for a seat belt retractor. Figure 1 This is a cross-sectional view of a gas generator for an airbag (hereinafter referred to as a gas generator only) 100 having an igniter assembly X1 according to Embodiment 1. Figure 1 The figure shows the state of the igniter before operation, indicated by reference numeral 40. The gas generator 100 is configured as a so-called single-type gas generator equipped with one igniter. Figure 1 As shown, the gas generator 100 includes a housing 10, an igniter 40, a holding part 50, a cylindrical wall part 60, a cover member 70, a spring member SP1, and a filter F1. The gas generator 100 is configured such that by activating the igniter 40 disposed within the housing 10, a first gas generating agent 110 and a second gas generating agent 120 filled inside the housing 10 are combusted, releasing combustion gases as combustion products to the outside of the housing 10, thereby inflating a gas bladder (not shown). The components of the gas generator 100 will be described below.

[0032] [shell]

[0033] like Figure 1 As shown, the outer casing 10 is formed into a short-sized cylindrical shape with both ends closed axially by joining an upper casing 20 and a lower casing 30, each formed as a bottomed cylindrical metal structure, with their open ends facing each other. However, the configuration of the upper casing 20 and the lower casing 30 is not limited to this, and known configurations can be used appropriately. Here, the direction along the axial direction of the outer casing 10 is defined as the vertical direction of the gas generator 100, and the direction along the upper casing 20 side (i.e., Figure 1 The upper side of the gas generator 100 is set as the upper side of the gas generator 100, and the lower housing 30 side (i.e., Figure 1 The lower side of the gas generator 100 is designated as the lower side of the gas generator 100.

[0034] The upper housing 20 has: a cylindrical upper cylinder portion 201; a top plate portion 202 that closes the upper end of the upper cylinder portion 201; and a joint portion 203 that extends radially outward from the lower end of the upper cylinder portion 201. The lower housing 30 has: a cylindrical lower cylinder portion 301; a bottom plate portion 302 that closes the lower end of the lower cylinder portion 301; and a joint portion 303 that extends radially outward from the upper end of the lower cylinder portion 301. The joint portion 203 of the upper housing 20 and the joint portion 303 of the lower housing 30 are overlapped and joined by laser welding or the like to form the outer casing 10. Furthermore, a plurality of gas vent holes 102 that communicate between the inside and outside of the outer casing 10 are formed in the upper cylinder portion 201 of the upper housing 20 in a circumferentially arranged manner. Before the igniter 40 is activated, the gas vent holes 102 are closed by a sealing strip (not shown).

[0035] Here, as Figure 1 As shown, a mounting portion 304 for assembling the igniter 40 is provided in the lower housing 30 of the outer casing 10. In this embodiment, the mounting portion 304 is integrally formed with the base plate portion 302. That is, the mounting portion 304 is made of metal and is formed from a part of the outer casing 10. Figure 1 As shown, the mounting portion 304 protrudes upward from the base plate portion 302 through a part of the lower housing 30 and is formed in a generally cylindrical shape. Furthermore, a mounting hole 304a is formed at the upper end of the mounting portion 304 for inserting a pair of energizing pins 4 of the igniter 40. The igniter assembly X1 of Embodiment 1 is configured to include an igniter 40, a mounting portion 304, a retaining portion 50, a cylindrical wall portion 60, and a cover member 70.

[0036] [Igniter]

[0037] Figure 2 This is a cross-sectional view of the igniter assembly X1 according to Embodiment 1. Figure 2 The image shows the state of the igniter 40 before it operates. For example... Figure 2 As shown, the igniter 40 includes a metal cup body 1, a metal head 2, an initiating charge 3, and a pair of energizing pins 4 (41, 42), which serve as an example of a "receptacle" of this disclosure. The cup body 1 is formed of a bottomed cylindrical shape from a metal material, having a cylindrical peripheral wall portion 11 and a capping wall portion 12 that closes one end (upper end) of the peripheral wall portion 11. The metal material forming the cup body 1 is not particularly limited; examples include stainless steel, aluminum, and iron. The metal head 2 is a cylindrical closing member formed of a metal material, disposed inside the cup body 1 in a manner that closes the opening formed at the other end (lower end) of the peripheral wall portion 11. The metal head 2 is welded to the inner wall of the peripheral wall portion 11 on its outer peripheral surface. Figure 2As shown, the metal head 2 is disposed inside the cup body 1 in such a way that the opening of the peripheral wall portion 11 is closed. Thus, the peripheral wall portion 11 of the cup body 1 includes, in its axial direction, a contact area A1 that contacts the peripheral wall portion 11 and a non-contact area A2 that is closer to the cover wall portion 12 than the contact area A1 and does not contact the metal head 2. The non-contact area A2 of the peripheral wall portion 11, the cover wall portion 12, and the metal head 2 define a receiving space 401 for filling the detonating charge 3. A pair of energizing pins 4 extend downward from the metal head 2. A connector (not shown) for supplying power from an external power source is connected to the pair of energizing pins 4.

[0038] The igniter 40 operates by supplying power to each energizing pin 4 via a connector, igniting the detonator 3 filled in the receiving space 401. Due to the combustion pressure of the detonator 3, the cover wall 12 of the cup body 1 cracks, thereby releasing the combustion products of the detonator 3 to the outside of the cup body 1.

[0039] [Maintenance Department]

[0040] The retaining part 50 is formed of resin material and is disposed between the igniter 40 and the mounting part 304 to fix the igniter 40 to the mounting part 304. At this time, as... Figure 2 As shown, the retaining part 50 holds the igniter 40 in the following state: the cup body 1 and the metal head 2 are located inside the housing 10, and a pair of energized pins 4 are inserted through the mounting hole 304a, with their top ends located outside the housing 10. The retaining part 50 secures the igniter 40 to the mounting part 304 by covering the contact area A1 of the peripheral wall 11, the metal head 2, and the mounting part 304, and maintains the airtightness of the housing 10 by blocking the mounting hole 304a. Furthermore, a portion of the retaining part 50 has a connector insertion space 501 formed inside the mounting part 304, into which a connector for supplying power to the energized pins 4 can be inserted. The retaining part 50 holds the igniter 40 such that the non-contact area A2 of the peripheral wall 11 and the cover wall 12 are exposed in the discharge space 601 (described later), and the lower ends of the pair of energized pins 4 are exposed in the connector insertion space 501. By covering a portion of the pair of energized pins 4 with the retaining part 50, the pair of energized pins 4 are kept insulated from each other.

[0041] [cylindrical wall part]

[0042] like Figure 2As shown, the cylindrical wall portion 60 is formed of resin material in a cylindrical shape, surrounding the peripheral wall portion 11 (more specifically, the non-contact area A2 of the peripheral wall portion 11) of the cup body 1, and extends upward from the holding portion 50. A discharge space 601 is formed on the inner side of the cylindrical wall portion 60, serving as a space for releasing the combustion products of the initiating explosive 3. The discharge space 601 is filled with a first gas generating agent 110 that burns upon operation of the igniter 40. The first gas generating agent 110 is ignited by the combustion products of the initiating explosive 3 released upon operation of the igniter 40, generating combustion gas. The holding portion 50 and the cylindrical wall portion 60 are integrally formed as a single component and are continuous with each other. Furthermore, multiple connecting holes 602 are formed in the cylindrical wall portion 60 in a circumferentially arranged manner, communicating between the inside and outside of the discharge space 601.

[0043] The retaining portion 50 and the cylindrical wall portion 60 are integrally formed by injection molding of resin material during the manufacturing process of the igniter assembly X1. As the resin material forming the retaining portion 50 and the cylindrical wall portion 60, a resin material with excellent heat resistance, durability, and corrosion resistance after curing can be appropriately used. Examples of such resin materials include thermoplastic resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin, vulcanized polypropylene resin, and polypropylene oxide resin, as well as thermosetting resins such as epoxy resin.

[0044] [Cover component]

[0045] like Figure 1 As shown, the cover member 70 is a member that defines the release space 601 together with the cylindrical wall portion 60 by being inserted into the cylindrical wall portion 60 through an opening formed at the upper end of the cylindrical wall portion 60. Furthermore, as... Figure 1 As shown, the cover member 70 closes the communication hole 602 by covering the communication hole 602 from the inside of the cylindrical wall portion 60 before the igniter 40 is operated.

[0046] [Spring component]

[0047] like Figure 1 As shown, the spring member SP1 is an elastic member provided between the cover member 70 and the top plate portion 202 of the upper housing 20. The spring member SP1 presses the cover member 70 downward (i.e., towards the release space 601 side) by applying force, thereby suppressing the sloshing of the first gas generator 110 that is detached from the cylindrical wall portion 60 and filled into the release space 601.

[0048] [Filter]

[0049] like Figure 1As shown, the filter F1 is cylindrical, with its upper end supported by the top plate 202 of the upper housing 20 and its lower end supported by the bottom plate 302 of the lower housing 30, positioned between the igniter assembly X1 and the gas outlet 102. Thus, a combustion chamber 101 is formed between the igniter assembly X1 and the filter F1. The combustion chamber 101 is filled with a second gas generator 120 that burns through the operation of the igniter 40. The second gas generator 120 is ignited by the combustion gas of the first gas generator 110 that burns through the operation of the igniter 40, generating 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 by passing through the filter F1. At this time, the filter F1 filters the combustion gas by capturing combustion residue.

[0050] [Gas Generator]

[0051] The first gas generator 110 uses a gas generator with a low combustion temperature. Ideally, the combustion temperature of the first gas generator 110 is in the range of 1000°C to 1700°C. For example, a single-hole cylindrical gas generator containing guanidine nitrate (41% by weight), basic copper nitrate (49% by weight), and binders and additives can be used. Furthermore, the second gas generator 120 may also use the same gas generator as the first gas generator 110. However, the first gas generator 110 and the second gas generator 120 are not limited to the above. Moreover, the first gas generator 110 and the second gas generator 120 can be gas generators of the same type, shape, and size, or they can be gas generators of different types, shapes, and sizes.

[0052] [action]

[0053] Next, the operation of the gas generator 100 will be explained. With the gas generator 100 installed in the vehicle, the connector inserted into the connector insertion space 501 connects to the igniter 40, enabling power to be supplied to the igniter 40. In this state, when a sensor (not shown) mounted on the vehicle detects an impact, power from an external power source is supplied via the connector to a pair of energizing pins 4, thereby activating the igniter 40 and igniting the detonator 3 within the containment space 401.

[0054] As the detonator 3 burns, the pressure within the containment space 401 rises, causing the cup 1 to rupture and releasing a high-temperature flame, a combustion product of the detonator 3, into the release space 601. This ignites the first gas generator 110 in the release space 601. Due to the pressure of the combustion gases of the first gas generator 110 (hereinafter also referred to as combustion pressure), the cover member 70 slides upward (i.e., towards the open end of the cylindrical wall portion 60) against the force applied by the spring member SP1. This eliminates the blockage of the communication hole 602 created by the cover member 70, allowing the combustion gases of the first gas generator 110 to exit through the communication hole 602 into the combustion chamber 101.

[0055] The second gas generator 120 is ignited by the combustion gas of the first gas generator 110 discharged from the connecting hole 602 into the combustion chamber 101, thereby generating combustion gas of the second gas generator 120 within the combustion chamber 101. After being cooled and filtered by the filter F1, the combustion gas within the combustion chamber 101 breaks the sealing strip blocking the gas outlet 102, releasing it from the gas outlet 102 to the outside of the outer casing 10. This causes the airbag to inflate, forming a buffer between the occupant and the rigid structure, protecting the occupant from impact.

[0056] [Covering wall section]

[0057] When the igniter 40 is operating, the pressure inside the receiving space 401 rises due to the combustion of the initiating explosive 3 filled in the receiving space 401, thereby causing the cover wall 12 of the cup body 1 to crack. As a result, the flame, a combustion product of the initiating explosive 3, is released into the release space 601, igniting the first gas generating agent 110 within the release space 601. At this time, the cover wall 12 of the cup body 1 deforms in the following manner: cracking begins at the central portion of the peripheral wall 11 in the radial direction, and opening outwards in the radial direction from the upper end of the peripheral wall 11. It should be noted that in the following description, unless otherwise specified, "radial" refers to the radial direction of the peripheral wall 11. Here, it is assumed that when the cover wall 12 opens significantly, and the cracked cover wall 12 comes into strong contact with the cylindrical wall 60, exerting a large load on the cylindrical wall 60, the cylindrical wall 60 deforms, potentially causing cracks or breakage. In such a situation, the cracks and damage may be transmitted to the retaining part 50, which may cause insufficient retention of the igniter 40 or damage to the sealing of the gas generator 100.

[0058] In contrast, in the igniter assembly X1 of this embodiment, the cover wall portion 12 of the cup body 1 is configured to suppress the large opening of the cover wall portion 12 when the igniter 40 is operating, thereby suppressing the load that acts heavily on the cylindrical wall portion 60. Hereinafter, the cover wall portion 12 will be described in detail.

[0059] Figure 3This is a cross-sectional view showing the state near the cup body 1 before the igniter 40 is operated in the igniter assembly X1 of Embodiment 1. Figure 4 This is a top view showing the state of the cover wall 12 of the cup body 1 before the igniter 40 operates in the igniter assembly X1 of Embodiment 1. Figure 3 and Figure 4 As shown, the cup body 1 of this embodiment includes a lid wall portion 12 comprising: an annular outer peripheral region portion 121 connected to the upper end (one end) of the peripheral wall portion 11; and a central region portion 122 located radially inside the outer peripheral region portion 121.

[0060] like Figure 3 As shown, the outer peripheral region 121 extends radially inward from the upper end of the peripheral wall portion 11, forming a ring around the central axis CA1 of the peripheral wall portion 11. The central region 122 is the portion of the cover wall portion 12 surrounded by the outer peripheral region 121, and is connected to the inner periphery of the outer peripheral region 121. The central region 122 is formed at a position radially inward than the outer peripheral region 121, and its radially central portion C1 is located on the central axis CA1 of the peripheral wall portion 11. Figure 3 As shown, if the wall thickness of the outer peripheral region 121 (the axial thickness of the peripheral wall 11) is set as T1, and the wall thickness of the central region 122 is set as T2, then T1>T2. That is to say, the outer peripheral region 121 is formed to have a thicker wall than the central region 122.

[0061] Here, the surface of the cover wall 12 facing the release space 601 (i.e., the upper surface of the cover wall 12) is designated as the release surface S1, and the surface of the cover wall 12 that defines the receiving space 401 (i.e., the lower surface of the cover wall 12), which is the opposite side of the release surface, is designated as the receiving surface S2. At this time, as... Figure 3 As shown, the outer peripheral region 121 and the central region 122 are connected by the projection surface S1 being recessed in the central region 122 toward the receiving space 401. As a result, a step portion 123 is formed on the projection space 601 side at the connection portion between the outer peripheral region 121 and the central region 122.

[0062] In addition, such as Figure 4 As shown, a plurality of grooves 13 are formed in the central region 122, extending radially from the center C1 of the central region 122. The plurality of grooves 13 are formed on the discharge surface S1 side and extend radially from the center C1 to the outer peripheral region 121. Figure 4 As shown, in this embodiment, the eight slots 13 are formed at equal angular intervals. However, the technology disclosed herein is not limited to this.

[0063] In addition, such as Figure 3As shown, if the radial distance from the center C1 of the central region 122 to the outer peripheral region 121 is defined as d1, and the radial distance from the center C1 to the cylindrical wall 60 (more specifically, the inner peripheral surface 60a of the cylindrical wall 60) is defined as d2, then d1 ≤ 1 / 2 × d2. That is, d1 is less than or equal to 1 / 2 of d2.

[0064] [Function / Effect]

[0065] Figure 5 This is a cross-sectional view showing the state after the igniter 40 operates and causes the cover wall portion 12 of the cup body 1 to crack in the igniter assembly X1 of Embodiment 1. As described above, the igniter assembly X1 of this embodiment includes: an igniter 40, which, when operated, causes the cover wall portion 12 of the metal cup body 1 to crack, thereby releasing the combustion products of the initiating explosive 3 to the outside of the cup body 1; and a resin cylindrical wall portion 60, which is formed in a cylindrical shape to surround the peripheral wall portion 11 of the cup body 1, and forms a release space 601 on the inside for releasing the combustion products of the initiating explosive 3. Furthermore, the cover wall portion 12 includes: an annular outer peripheral region portion 121, which is disposed radially inward of the peripheral wall portion 11; and a central region portion 122, which is disposed radially inward of the outer peripheral region portion 121, and the outer peripheral region portion 121 is formed as a wall thicker than the central region portion 122.

[0066] The central region 122 has a thinner wall than the outer peripheral region 121. Therefore, if the lid wall 12 of the cup body 1 cracks due to the operation of the igniter 40, such as... Figure 5 As shown, the central region 122 becomes the starting point of the crack. At this time, due to the combustion pressure of the detonator 3, the cover wall 12 deforms by opening towards the release space 601, starting from the upper end of the peripheral wall 11. Here, in the igniter assembly X1, the outer peripheral region 121 is formed as a wall thicker than the central region 122, therefore, the outer peripheral region 121 is more rigid and less prone to deformation than the central region 122. Accordingly, since the outer peripheral region 121 connected to the peripheral wall 11 is less prone to deformation, the large-scale opening of the cover wall 12 is suppressed. Therefore, the strong contact between the cracked cover wall 12 and the cylindrical wall 60 is suppressed. That is to say, the cracked cover wall 12 will not contact the cylindrical wall 60, or even if it does, it will not generate a large load.

[0067] Therefore, according to the igniter assembly X1 of this embodiment, the large load exerted on the cylindrical wall portion 60 by the cracked cover wall portion 12 when the igniter 40 is working can be suppressed, and the cylindrical wall portion 60 can be prevented from developing cracks, damage or other adverse conditions.

[0068] In addition, such as Figure 5As shown, when the cover wall portion 12 cracks due to the operation of the igniter 40, the central region portion 122 deforms and opens towards the release space 601, starting from the connection portion with the outer peripheral region portion 121. Here, in the igniter assembly X1, the outer peripheral region portion 121 and the central region portion 122 are connected by the release surface S1 of the cover wall portion 12 being recessed in the central region portion 122. Therefore, a stepped portion 123 is formed at the connection portion between the outer peripheral region portion 121 and the central region portion 122 on the release space 601 side. Thus, as... Figure 5 As shown, the stepped portion 123 abuts against the central region portion 122, thereby suppressing further opening of the central region portion 122. As a result, according to the igniter assembly X1, it is possible to prevent the central region portion 122 from opening excessively and making strong contact with the cylindrical wall portion 60 when the igniter 40 is operating. It should be noted that the technology disclosed herein is not limited to this; alternatively, the outer peripheral region portion and the central region portion could be connected by the central region portion being recessed in the receiving surface facing the receiving space.

[0069] Furthermore, in the igniter assembly X1 of this embodiment, a plurality of grooves 13 extending radially from the center C1 of the central region 122 of the cover wall portion 12 are formed. The portion of the central region 122 with the grooves 13 is more fragile than other portions. In the igniter assembly X1, the plurality of grooves 13 are formed radially from the center C1, thus making the cover wall portion 12 prone to cracking. Moreover, in the igniter assembly X1, the grooves 13 are formed only in the central region 122 of the outer peripheral region 121 and the central region 122. According to such an igniter assembly X1, deformation of the outer peripheral region 121 can be suppressed while making the cover wall portion 12 prone to cracking. It should be noted that, in the technology disclosed herein, the grooves in the central region are not a necessary feature.

[0070] Furthermore, in the igniter assembly X1 of this embodiment, the radial distance d1 from the center C1 of the central region 122 of the cover wall portion 12 to the outer peripheral region 121 is less than half of the radial distance from the center C1 to the cylindrical wall portion 60. Therefore, even if the central region 122 deforms and leans towards the cylindrical wall portion 60 when the igniter 40 is operating, folding back from the connection point with the outer peripheral region 121, the central region 122 will not reach the cylindrical wall portion 60. As a result, according to the igniter assembly X1, contact between the central region 122, which may crack during ignition of the igniter 40, and the cylindrical wall portion 60 can be prevented. However, the technology disclosed herein is not limited to this.

[0071] [Variation Example]

[0072] Figure 6This is a cross-sectional view showing the state near the cup 1A before the igniter 40 operates in the igniter assembly X1A of the modified embodiment 1. Hereinafter, the modified igniter assembly X1A will be described with a focus on the differences from the igniter assembly X1, and detailed descriptions will be omitted by using the same reference numerals to refer to the same components.

[0073] like Figure 6 As shown, the modified igniter assembly X1A differs from the igniter assembly X1 in that the cup body 1A is formed by two parts. More specifically, the cup body 1A includes a cup body 1b formed as a bottomed cylindrical shape and an annular ring member 1c. The cup body 1b has a peripheral wall portion 11 and a cover wall portion body 1b2 that closes one end (upper end) of the peripheral wall portion 11. A cover wall portion 12A is formed by providing the ring member 1c on the cover wall portion body 1b2. The ring member 1c overlaps with the cover wall portion body 1b2 to form an outer peripheral region portion 121 together with the cover wall portion body 1b2. In the cover wall portion 12A, the outer peripheral region portion 121 is formed in the area of ​​the cover wall portion body 1b2 where the ring member 1c overlaps, and a central region portion 122 is formed in the area of ​​the cover wall portion body 1b2 where the ring member 1c does not overlap. Thus, the outer peripheral region portion 121 is formed as a wall thicker than the central region portion 122. It should be noted that, as Figure 6 As shown, a fitting portion 1c1 is formed in the ring member 1c that fits into the cover wall body 1b2. This prevents the ring member 1c from falling off the cover wall body 1b2 and keeps the cup body 1b and the ring member 1c as one unit.

[0074] In the modified igniter assembly X1A, the cover wall portion 12A of the cup body 1A includes: an annular outer peripheral region portion 121, configured to be radially inner than the peripheral wall portion 11; and a central region portion 122, configured radially inner than the outer peripheral region portion 121, wherein the outer peripheral region portion 121 is formed as a wall thicker than the central region portion 122. Accordingly, similar to the igniter assembly X1, it is possible to suppress the large load exerted on the cylindrical wall portion 60 by the cracked cover wall portion 12A when the igniter 40 is operating, and to prevent defects such as cracks and damage from occurring in the cylindrical wall portion 60.

[0075] <Implementation Method 2>

[0076] Figure 7 This is a cross-sectional view of the igniter assembly X2 according to Embodiment 2. Figure 7The diagram shows the state of the igniter 40 before operation. The igniter assembly X2 of Embodiment 2 is an igniter assembly obtained by applying the technology of this disclosure to an igniter assembly for a gas generator for a seatbelt retractor. However, the application of the igniter assembly X2 of Embodiment 2 is not limited to this; for example, it can also be applied to a gas generator for an airbag. Hereinafter, the igniter assembly X2 of Embodiment 2 will be described focusing on the differences from the igniter assembly X1 of Embodiment 1, and detailed descriptions will be omitted by using the same reference numerals to denote the same components.

[0077] In Embodiment 2, the igniter assembly X2 is inserted into a gas generator (not shown) for a seat belt retractor, configured to: ignite the igniter 40 to burn the first gas generator 110 filled in the release space 601 and release combustion gas as its combustion product, thereby retracting the slack of the seat belt.

[0078] like Figure 7 As shown, the igniter assembly X2 of Embodiment 2 is configured to include an igniter 40, an assembly portion 80, a retaining portion 50, a cylindrical wall portion 60, and a cover member 90. The assembly portion 80 is a cylindrical collar member formed of metal material, which differs from the assembly portion 304 of Embodiment 1 in that it is separated from the outer casing. A pair of power pins 4 of the igniter 40 are inserted into the assembly portion 80. The igniter 40 is fixed to the assembly portion 80 by the retaining portion 50 provided between the igniter 40 and the assembly portion 80. The assembly portion 80 is fixed to the outer casing of the gas generator, thereby assembling the igniter assembly X2 into the gas generator. The cover member 90 is a bottomed cylindrical member that closes the opening 603 of the cylindrical wall portion 60 by being externally fitted into the upper end of the cylindrical wall portion 60, and together with the cylindrical wall portion 60, defines the release space 601. Furthermore, the cylindrical wall portion 60 of Embodiment 2 does not have a connecting hole 602.

[0079] In Embodiment 2, when the igniter 40 operates, the cup 1 ruptures due to the combustion of the initiating explosive 3 within the containing space 401, releasing a high-temperature flame, which is a combustion product of the initiating explosive 3, into the release space 601. This ignites the first gas generating agent 110 filling the release space 601. Due to the combustion pressure of the first gas generating agent 110, the cover member 90 cracks, thereby releasing the combustion gases of the first gas generating agent 110 from the opening 603 of the cylindrical wall portion 60.

[0080] As described above, in the igniter assembly X2 of Embodiment 2, the cover wall portion 12 of the cup body 1 also includes: an annular outer peripheral region portion 121, configured to be radially inner than the peripheral wall portion 11; and a central region portion 122, configured radially inner than the outer peripheral region portion 121, wherein the outer peripheral region portion 121 is formed as a wall thicker than the central region portion 122. Accordingly, the same effect as that of the igniter assembly X1 of Embodiment 1 can be obtained. That is, according to the igniter assembly X2 of Embodiment 2, the large load exerted on the cylindrical wall portion 60 by the cracked cover wall portion 12 during the operation of the igniter 40 can be suppressed, and the occurrence of defects such as cracks and damage in the cylindrical wall portion 60 can be suppressed.

[0081] <Other>

[0082] The embodiments of the igniter assembly and gas generator disclosed herein have been described above. However, the various solutions disclosed herein can also be combined with any other features disclosed herein. Furthermore, in the above embodiments, the application of the igniter assembly of this disclosure to a single-type gas generator having only one igniter was described as an example. However, the igniter assembly of this disclosure can also be applied to gas generators having multiple igniters. Furthermore, in the above embodiments, the application of the igniter assembly to a gas generator for airbags or seatbelt retractors was described as an example. However, it can also be applied to other gas generators. Additionally, the outer casing of the gas generator, other than its housing, can be used as the assembly object of the igniter assembly.

[0083] Explanation of reference numerals in the attached figures

[0084] 1: Cup body (an example of a container);

[0085] 11: Peripheral section;

[0086] 12: Cover wall part;

[0087] 121: Peripheral area department;

[0088] 122: Central Regional Department;

[0089] 13: trough;

[0090] 3: Detonating explosive;

[0091] 10: Outer shell;

[0092] 40: Ignition device;

[0093] 401: Accommodation space;

[0094] 50: Maintaining part;

[0095] 60: cylindrical wall;

[0096] 601: Release space;

[0097] 100: Gas generator;

[0098] 101: Combustion chamber;

[0099] 102: Gas vent hole;

[0100] 110: First gas generating agent;

[0101] 120: Second gas generator;

[0102] X1: Ignition unit assembly;

[0103] S1: Release the surface.

Claims

1. An ignition assembly, comprising: An igniter includes a metal container and an initiating explosive. The metal container has a cylindrical peripheral wall and a cover wall that closes one end of the peripheral wall. The initiating explosive fills a space defined by the peripheral wall and the cover wall. When the igniter is activated, the cover wall cracks, thereby releasing the combustion products of the initiating explosive to the outside of the container. The resin-made cylindrical wall is formed in a cylindrical shape to surround the peripheral wall, and an outlet space is formed on the inside for the combustion products of the detonator to be released. The cover wall portion includes: The annular outer peripheral region is configured to be radially inner than the peripheral wall portion; and the central region is configured radially inner than the outer peripheral region. The outer periphery of the outer peripheral region is connected to the peripheral wall portion at the first connecting portion, and the outer periphery of the central region is connected to the outer peripheral region portion at the second connecting portion. The outer peripheral region is formed with a wall that is thicker than the central region. When the igniter is in operation, the annular outer peripheral region is configured to deform upward at a first angle relative to the central axis of the igniter at the first connecting portion, and the central region is configured to deform upward at a second angle relative to the annular outer peripheral region at the second connecting portion.

2. The igniter assembly according to claim 1, wherein, The outer peripheral region and the central region are connected in such a way that the release surface facing the release space in the cover wall is recessed in the central region.

3. The igniter assembly according to claim 1 or 2, wherein, Multiple grooves are formed in the central region, extending radially from the center of the central region.

4. The igniter assembly according to claim 1 or 2, wherein, The radial distance from the center of the central region to the outer peripheral region is less than 1 / 2 of the radial distance from the center to the cylindrical wall.

5. The igniter assembly according to claim 1 or 2, wherein, The release space is filled with a first gas generator ignited by the combustion products of the initiating explosive.

6. A gas generator, comprising: Igniter assembly as described in any one of claims 1 to 5; The outer casing is fitted with the igniter assembly; A combustion chamber, formed inside the outer casing, is filled with a second gaseous agent that burns upon operation of the igniter; and A gas exhaust port is formed in the housing, connecting the combustion chamber to the external space of the housing.

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