Gas generator

Abstract

A gas generator (1) is provided with an igniter assembly (2), a cup (40), and a gas generating agent (50). The igniter assembly (2) is provided with a metal holder (10), an igniter (20), and a resin molded part (30). The cup (40) has a flange section (43), and the igniter assembly (2) is provided with an annular groove section for receiving the flange section (43). The inner wall surface of the annular groove portion is defined by the outer peripheral surface of a first covering portion (31) of the resin molding portion (30), the bottom surface of the annular groove portion is defined by a first end surface (10a) of the holder (10), and the outer wall surface of the annular groove portion is defined by the inner peripheral surface of an annular flange portion (13) provided on the holder (10). The cup (40) is assembled to the holder (10) in a state in which the boundary line between the first end surface (10a) of the holder (10) and the outer peripheral surface of the first cover section (31) is covered by a sealant (60) applied to the inside of the annular groove section by bending the annular flange section (13) inward.

Description

Technical Field

[0001] The present invention relates to a gas generator, and more particularly to a small gas generator configured to generate a relatively small amount of gas during operation. Background Art

[0002] Conventionally, from the viewpoint of protecting occupants of automobiles and the like, seat belt devices as occupant protection devices have been popularized. The seat belt device is equipped for the purpose of protecting an occupant from the impact generated during a collision of a vehicle or the like, and is a device that restrains the occupant to the seat by winding a seat belt around the occupant's body. Thereby, the occupant is prevented from being thrown inside or outside the vehicle during a collision of the vehicle or the like.

[0003] In a seat belt device, a small gas generator called a micro gas generator is incorporated in a seat belt device having a so-called pretensioner. The pretensioner is a device that instantaneously winds up the slack of the seat belt caused by the thickness of clothes or the like when a collision of a vehicle or the like is detected, and such a function is achieved by strongly pulling one end of the seat belt by the pressure of the gas output from the gas generator.

[0004] Generally, in such a gas generator, it is manufactured by fixing a bottomed substantially cylindrical cup filled with a gas generating agent to an igniter assembly, which is an assembly in which an igniter for burning the gas generating agent is pre-assembled to a holder.

[0005] There are various structures in the assembly structure of the igniter with respect to the holder. Among them, an assembly structure in which the igniter is assembled to the holder by injection molding (more specifically, insert molding) using a resin material as a raw material is known. As documents disclosing such an assembly structure, for example, there are Japanese Patent Application Laid-Open No. 2003-161599 (Patent Document 1), Utility Model Registration No. 3134430 (Patent Document 2), Japanese Patent Application Laid-Open No. 2010-276263 (Patent Document 3), Japanese Patent Application Laid-Open No. 2019-99022 (Patent Document 4), and the like.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-161599

[0009] Patent Document 2: Japanese Utility Model Registration No. 3134430

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2010-276263

[0011] Patent Document 4: Japanese Unexamined Patent Application Publication No. 2019-99022 Summary of the Invention

[0012] Problems to be Solved by the Invention

[0013] Here, when the igniter is assembled to the holder by injection molding using a resin material as a raw material, it is necessary to reliably ensure the sealing performance at the interface between the resin molded part formed by injection molding and the holder for a long period of time. In this regard, in the above Patent Documents 1 to 4, it is configured to ensure the sealing performance by imparting various unevenness such as a standing wall portion and a groove portion to the surface of the holder of the portion covered with the resin molded part.

[0014] However, in order to ensure the sealing performance by imparting various unevenness such as a standing wall portion and a groove portion to the surface of the holder, it is necessary to perform very high-precision cutting on the holder, which is the main reason for significantly increasing the manufacturing cost.

[0015] Therefore, the present invention has been made to solve the above problems, and an object thereof is to provide a gas generator that can reliably ensure the sealing performance at the interface between the resin molded part and the holder for a long period of time and can be manufactured at low cost.

[0016] Means for Solving the Problems

[0017] The gas generator according to the present invention includes: a gas generating agent that generates gas by combustion; a bottomed substantially cylindrical cup that houses the gas generating agent and has one end in the axial direction configured as an open end; and an igniter assembly that has a substantially cylindrical outer shape and closes the open end of the cup by coaxially assembling the cup. The igniter assembly includes: an igniter having an ignition portion filled with an igniting powder and a terminal pin connected to the ignition portion; a substantially cylindrical metal holder having a first end face as an axial end face on the side facing the cup, a second end face as an axial end face on the side not facing the cup, and a through hole that reaches the first end face and the second end face and through which at least a part of the igniter is inserted; and a resin molding portion that fills the space between the igniter and the holder to fix the igniter to the holder so that the ignition portion faces the gas generating agent. A protruding annular flange portion is provided on the first end face of the holder so as to surround the through hole. The resin molding portion has a first covering portion that adheres to and covers a portion of the first end face of the holder located around the through hole, a second covering portion that adheres to and covers a portion of the second end face of the holder located around the through hole, and a connecting portion that connects the first covering portion and the second covering portion by filling the through hole. The cup has a flange portion that extends outward from the open end; an annular groove portion for receiving the flange portion is provided on the axial end face of the igniter assembly on the side facing the cup. The inner wall surface of the annular groove portion is defined by the outer peripheral surface of the first covering portion; the bottom surface of the annular groove portion is defined by the first end face of the holder; the outer wall surface of the annular groove portion is defined by the inner peripheral surface of the annular flange portion. The gas generator according to the present invention is assembled to the holder by bending the annular flange portion inward in a state where a sealant is applied to the inside of the annular groove portion and the flange portion is received in the annular groove portion, so that the flange portion is sandwiched between the annular flange portion and the bottom surface of the annular groove portion in a state where the boundary line between the first end face of the holder exposed inside the annular groove portion and the outer peripheral surface of the first covering portion is covered by the sealant.

[0018] Advantages of the Invention

[0019] According to the present invention, it is possible to provide a gas generator that can reliably ensure the sealing property at the interface between the resin molding portion and the holder for a long time and can be manufactured at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic cross-sectional view of the gas generator according to the embodiment.

[0021] Figure 2 is a schematic cross-sectional view taken along line II-II shown in Figure 1 .

[0022] Figure 3 is Figure 1 an enlarged view of region III shown in

[0023] Figure 4 is Figure 1 a schematic cross-sectional view of an igniter assembly during the manufacture of the gas generator shown in

[0024] Figure 5 represents Figure 1 a schematic cross-sectional view of a method for manufacturing the gas generator shown in

[0025] Figure 6 represents Figure 1 a schematic cross-sectional view of a method for manufacturing the gas generator shown in

[0026] Figure 7 represents Figure 1 a schematic cross-sectional view of a method for manufacturing the gas generator shown in

[0027] Figure 8 represents Figure 1 a schematic cross-sectional view of a method for manufacturing the gas generator shown in

[0028] Figure 9 represents Figure 1 a schematic cross-sectional view of the state where the gas generator shown in is installed in a pretensioner.

[0029] Figure 10 represents a schematic cross-sectional view of a method for installing a short-circuit clip on the gas generator shown in Figure 1 . DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following-described embodiments illustrate cases where the present invention is applied to a gas generator (so-called micro gas generator) appropriately installed in a seat belt device equipped with a pretensioner. In addition, in the following-described embodiments, the same or common parts are given the same reference numerals in the drawings, and their descriptions are not repeated.

[0031] Figure 1 is a schematic cross-sectional view of a gas generator related to an embodiment, Figure 2 is a schematic cross-sectional view taken along line II-II shown in Figure 1 . In addition, Figure 3 is Figure 1 an enlarged view of region III shown in Figure 4 is Figure 1Schematic cross-sectional view of the igniter assembly during the manufacture of the gas generator shown. First, refer to these Figures 1 to 4 The structure of the gas generator 1 according to the present embodiment will be described.

[0032] As Figures 1 to 3 shown, the gas generator 1 according to the present embodiment includes an igniter assembly 2, a bottomed substantially cylindrical cup 40, a gas generant 50, and a sealant 60. The igniter assembly 2 has a substantially cylindrical outer shape and is composed of a retainer 10, an igniter 20, and a resin molded portion 30. In the gas generator 1, by arranging the cup 40 coaxially with the igniter assembly 2 and assembling it thereto, a casing that becomes the outer casing of the gas generator 1 is formed by the retainer 10 and the resin molded portion 30 in the igniter assembly 2, and the cup 40.

[0033] The gas generant 50 is housed in the space defined by the igniter assembly 2 and the cup 40. The igniter 20 is fixed to the retainer 10 via the resin molded portion 30 so that its ignition portion 21 faces the gas generant 50. In addition, the sealant 60 is provided at a predetermined position between the cup 40 and the igniter assembly 2 so as to be sandwiched therebetween. Details thereof will be described later.

[0034] As Figure 1 and Figure 2 shown, the retainer 10 is a member for holding the igniter 20 and the cup 40 and has a substantially cylindrical outer shape. Here, in the present embodiment, since the recess 14 and the through hole 10c described later are provided in the retainer 10, the retainer 10 substantially has a substantially cylindrical shape.

[0035] More specifically, the retainer 10 includes a cylindrical body portion 11 and a substantially disc-shaped partition portion 12 located inside the body portion 11 and at the axial end on the cup 40 side of the body portion 11. The through hole 10c having an opening shape is located at the center of the partition portion 12, and the recess 14 is located inside the body portion 11 and at the axial end on the side opposite to the cup 40 side of the body portion 11. These through holes 10c and the recess 14 communicate with each other.

[0036] Here, the retainer 10 has a first end face 10a which is the axial end face on the side facing the cup 40, and the first end face 10a is defined by the axial end face on the cup 40 side of the body portion 11 and the main face on the cup 40 side of the partition portion 12. In addition, the retainer 10 has a second end face 10b which is the axial end face on the side not facing the cup, and the second end face 10b is defined by the axial end face on the side opposite to the cup 40 side of the body portion 11 and the main face on the side opposite to the cup 40 side of the partition portion 12 (more precisely, since the above-mentioned recess 14 is provided on this main face, this main face is equivalent to the surface of the recess 14). In addition, the above-mentioned through portion 10c reaches both the first end face 10a and the second end face 10b of the retainer 10.

[0037] In addition, on the first end face 10a of the retainer 10, a protruding annular flange portion 13 is provided so as to surround the through portion 10c. The annular flange portion 13 is a portion for caulking and fixing a flange portion 43 of the cup 40 described later. During this caulking and fixing, the annular flange portion 13 is bent inward, and the flange portion 43 is sandwiched between the annular flange portion 13 and the first end face 10a, thereby fixing the cup 40 immovably relative to the retainer 10. In addition, the annular flange portion 13 is located at the outer edge portion of the first end face 10a, and thus the first end face 10a is located between the through portion 10c and the annular flange portion 13.

[0038] The retainer 10 is also a component that forms part of the shell as described above, and is formed of, for example, a formed product made of a metal material such as aluminum or an aluminum alloy. The retainer 10 is formed into the shape shown by, for example, performing forging, punching, and, if necessary, cutting on a plate-shaped metal component or a rod-shaped metal component serving as a raw material one or more times in a predetermined order. Figure 4 the shape shown.

[0039] The igniter 20 is a component for generating a flame and is also called a detonator. The igniter 20 has an ignition portion 21 and a pair of terminal pins 22. The ignition portion 21 includes an ignition charge that generates a flame by igniting combustion during operation and a resistor (bridge wire) for igniting the ignition charge inside. The pair of terminal pins 22 are connected to the ignition portion 21 to ignite the ignition charge.

[0040] More specifically, the ignition portion 21 includes a detonator cup formed in a cup shape and has the following structure: the above-mentioned resistor is installed in a manner that connects the front ends of the pair of terminal pins 22 inserted into the detonator cup, and the ignition charge is filled in the detonator cup so as to surround the resistor or be close to the resistor.

[0041] Here, as the resistor body, a nickel-chromium heat-resistant alloy wire or the like is generally used, and as the ignition charge, ZPP (zirconium-potassium perchlorate), ZWPP (zirconium-tungsten-potassium perchlorate), lead trinitroresorcinate, etc. are generally used. In addition, the above-mentioned detonator cup is generally made of metal or plastic.

[0042] When a collision is detected, a predetermined amount of current flows through the resistor body via the terminal pin 22. By flowing a predetermined amount of current through the resistor body, Joule heat is generated in the resistor body, and the ignition charge starts to burn. The high-temperature flame generated by the combustion causes the detonator cup containing the ignition charge to rupture. The time from when the current flows through the resistor body to when the igniter 20 operates is generally 2 ms or less when the resistor body uses a nickel-chromium heat-resistant alloy wire.

[0043] The igniter 20 is installed on the retainer 10 in a state where the terminal pin 22 is inserted through the through-hole 10c provided in the partition portion 12 of the retainer 10. Specifically, the above-mentioned resin molding portion 30 is provided around the retainer 10 to fill the space between the retainer 10 and the igniter 20, and the igniter 20 is assembled relative to the retainer 10 by being held by the resin molding portion 30.

[0044] The resin molding portion 30 is formed by injection molding (more specifically, insert molding) using a mold, and is formed by attaching an insulating fluid resin material to the retainer 10 in such a manner that it reaches a part of the second end surface 10b from a part of the first end surface 10a of the retainer 10 via the through-hole 10c provided in the partition portion 12 of the retainer 10 and curing it.

[0045] The igniter 20 is set to be inserted from the side of the first end surface 10a of the retainer 10 so that the terminal pin 22 is inserted through the through-hole 10c during the molding of the resin molding portion 30. In this state, the above-mentioned fluid resin material is caused to flow in to fill the space between the igniter 20 and the retainer 10, and the igniter 20 is fixed to the retainer 10 via the resin molding portion 30.

[0046] Here, the size of the through-hole 10c provided in the retainer 10 is configured to be smaller than the outer shape of the largest outer shape portion of the igniter 20, that is, the outer shape of the ignition portion 21. By configuring it in this way, even if an unexpected breakage occurs in the resin molding portion 30, it is possible to prevent the igniter 20 from flying out of the case to the outside through the through-hole 10c due to the increase in the internal pressure of the housing space 44 (that is, the space containing the gas generant 50) described later, and to ensure the safe operation of the gas generator 1.

[0047] As a raw material for the resin molded part 30 formed by injection molding, a resin material with excellent heat resistance, durability, corrosion resistance, etc. after curing is preferably selected and used. In this case, it is not limited to thermosetting resins represented by epoxy resins, etc., and thermoplastic resins represented by polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (such as nylon 6, nylon 66, etc.), polyphenylene sulfide resin, polypropylene oxide resin, etc. can also be used. When these thermoplastic resins are selected as raw materials, in order to ensure the mechanical strength of the resin molded part 30 after molding, it is preferable to make these resin materials contain glass fiber, etc. as fillers. However, when sufficient mechanical strength can be ensured only by the thermoplastic resin, it is not necessary to add the above-mentioned fillers.

[0048] The resin molded part 30 has: a first covering part 31 that covers a part of the first end face 10a of the retainer 10; a second covering part 32 that covers a part of the second end face 10b of the retainer 10; and a connecting part 33 that is located in the through-hole 10c of the partition wall part 12 provided in the retainer 10 and connects the first covering part 31 and the second covering part 32.

[0049] The resin molded part 30 is fixed to the retainer 10 on the surface of each of the first covering part 31, the second covering part 32, and the connecting part 33 on the retainer 10 side. In addition, the resin molded part 30 is fixed to the side surface and the lower surface of the part near the lower end of the ignition part 21 of the igniter 20 and the surface of the part near the upper end of the terminal pin 22 of the igniter 20, respectively. As a result, the through-hole 10c is in a state of being completely filled by the terminal pin 22 and the resin molded part 30, and by ensuring the airtightness at this part, the airtightness of the space inside the case is ensured.

[0050] Here, the first covering part 31 is formed to cover the part of the first end face 10a of the retainer 10 adjacent to the through-hole 10c, and its outer edge does not reach the annular convex edge part 13 and is located more inside at a distance from the annular convex edge part 13. Therefore, the part on the outer edge side of the first end face 10a of the retainer 10 is not covered by the first covering part 31 and is exposed.

[0051] In addition, in the first covering part 31, a reinforcing part 31a is provided that protrudes upward along the side surface of the ignition part 21 of the igniter 20. This reinforcing part 31a is a part for adjusting the opening state of the detonator cup of the igniter 20 that cracks during the operation of the gas generator 1 (that is, preventing the detonator cup from opening excessively). By providing this reinforcing part 31a, the hot particles generated by the operation of the igniter 20 can be made to have directivity, and the hot particles can be efficiently guided to the gas generating agent 50.

[0052] On the other hand, the second covering portion 32 is formed to include: a first portion 32a that covers the surface of the recess 14 in the second end face 10b of the retainer 10; and a second portion 32b that projects from the second end face 10b of the retainer 10 in a portion where the recess 14 is not provided (i.e., the second end face 10b of the portion defined by the body portion 11) toward the side opposite to the side where the cup 40 is located. Further, in the second covering portion 32, a concave female connector portion 32c is provided so as to straddle these first portion 32a and second portion 32b.

[0053] A pair of terminal pins 22 of the igniter 20 are located in the female connector portion 32c in an exposed state, whereby the female connector portion 32c functions as a portion for receiving a male connector (not shown) for external connection of the igniter 20 via the pair of terminal pins 22. That is, by inserting the male connector of the wire harness connected to the control unit (not shown) into the female connector portion 32c, electrical conduction between the core wire of the wire harness and the terminal pins 22 is achieved, thereby connecting the igniter 20 and the control unit.

[0054] In addition, in a portion of the inner side surface of the female connector portion 32c defined by the above-described second portion 32b (i.e., the portion of the second covering portion 32 that projects from the second end face 10b of the retainer 10 in a portion where the recess 14 is not provided), a locking portion 32b1 having a recessed shape for holding the short-circuit clip 80 (refer to Figure 10 ) is provided.

[0055] Here, in the gas generator 1 according to the present embodiment, a plurality of groove portions 14a are provided on the surface of the recess 14 so as to reach the second end face 10b of the retainer 10 in a portion where the recess 14 is not provided from the through-hole portion 10c of the partition portion 12 of the retainer 10. The groove portions 14a are provided so as to be scattered along the circumferential direction of the retainer 10. In the present embodiment, as Figure 2 shown, three groove portions 14a are provided so as to be equally arranged along the circumferential direction. All of these groove portions 14a are filled with the second covering portion 32 of the resin molding portion 30.

[0056] With such a configuration, the groove portions 14a and the second covering portion 32 of the portion filling them are engaged with each other, and the rotation of the resin molding portion 30 relative to the retainer 10 can be prevented beforehand. Further, with such a configuration, during the injection molding of the resin molding portion 30, its moldability is greatly improved, but this will be described in detail later.

[0057] In addition, in the gas generator 1 according to the present embodiment, as Figure 1As shown, when the protruding length of the second part 32b of the second covering part 32 is set as A, and the axial length of the retainer 10 in the state after the cup 40 is assembled to the retainer 10 (that is, the axial distance of the retainer 10 from the upper end of the bent annular convex edge part 13 to the second end face 10b of the retainer 10 at the part where the recess 14 is not provided) is set as B, these protruding length A and axial length B satisfy the condition of B < 1.8×A (hereinafter, this will be referred to as the "first condition").

[0058] In addition, in the gas generator 1 related to the present embodiment, as Figure 1 shown, when the depth of the female connector part 32c is further set as C, the above-mentioned protruding length A and this depth C satisfy the condition of C < 1.8×A (hereinafter, this will be referred to as the "second condition").

[0059] By satisfying at least one of these first condition and second condition, the protruding length A of the second part 32b of the second covering part 32 can be configured to be significantly long. Thus, the effect of facilitating the insertion of the male connector after the gas generator 1 described later is assembled to the pretensioner can be obtained, and the effect of being able to increase the filling amount of the gas generating agent 50 without increasing the size of the cup 40 can be obtained. However, these points will be described in detail later.

[0060] The igniter assembly 2 composed of the retainer 10, the igniter 20, and the resin molding part 30 described above is manufactured as a single part integrated by assembling them to each other in advance during the manufacture of the gas generator 1. Then, the gas generator 1 is manufactured by assembling the cup 40, the gas generating agent 50, and the sealant 60, which are the remaining parts, to the igniter assembly 2 as the single part.

[0061] Therefore, as Figure 4 shown, at the time when the igniter assembly 2 is manufactured, the above-mentioned annular convex edge part 13 provided on the first end face 10a of the retainer 10 has not been bent inward and is in a state of standing upright along the axial direction of the retainer 10. Therefore, in this state, the annular groove part 2a for receiving the flange part 43 of the cup 40 is located at the axial end face on the side of the igniter assembly 2 for assembling the cup 40 in a state of opening toward the outside. The inner side wall surface (that is, the side surface located on the radially inner side) of the annular groove part 2a is defined by the outer peripheral surface of the first covering part 31 of the resin molding part 30, the bottom surface of the annular groove part 2a is defined by the exposed part of the first end face 10a of the retainer 10, and the outer side wall surface (that is, the side surface located on the radially outer side) of the annular groove is defined by the inner peripheral surface of the annular convex edge part 13 provided on the retainer 10.

[0062] As Figure 1 and Figure 3As shown, the cup 40 is composed of a bottomed, substantially cylindrical member having an axially open end 41a, and includes a side wall portion 41, a bottom wall portion 42, and a flange portion 43. A gas generant 50 is accommodated in a housing space 44 of the cup 40 defined by the side wall portion 41 and the bottom wall portion 42.

[0063] The above-mentioned open end 41a is formed by an end portion on the side opposite to the side where the bottom wall portion 42 is located among a pair of axially end portions of the side wall portion 41. The flange portion 43 is positioned to extend outward from the open end 41a. The flange portion 43 is a part for fixing the cup 40 to the retainer 10.

[0064] On the bottom wall portion 42 of the cup 40, a score 42a is provided by forming a groove-like cut-in portion on its surface. The score 42a is provided to form a weakened portion that is weaker than other positions at a predetermined position on the bottom wall portion 42. By providing the score 42a, it can be configured that the cup 40 opens starting from this portion during the operation of the gas generator 1.

[0065] The cup 40 is also a component that forms part of the shell, and is formed of a molded product made of a metallic material such as an iron-based material including, for example, aluminum, aluminum alloy, and stainless steel. In addition, in the forming of the cup 40, generally, press working using a mold is utilized.

[0066] As described above, the cup 40 is assembled to the retainer 10 by caulking and fixing its flange portion 43 to the annular flange portion 13 of the retainer 10. Specifically, with the flange portion 43 of the cup 40 inserted into the above-mentioned annular groove portion 2a provided in the igniter assembly 2, the annular flange portion 13 is bent inward to fix the cup 40 to the igniter assembly 2.

[0067] The gas generant 50 generates a large amount of gas by being ignited and burned by the igniter 20. As the gas generant 50, a molded body of smokeless powder (nitrocellulose), a molded body of a non-azide-based composition formed of an organic nitrogen compound and an oxidant, etc. are used. In recent years, in addition, non-nitrocellulose-based gas generants that generate extremely small amounts of harmful substances such as carbon monoxide have received attention as the gas generant 50.

[0068] As the molded body of the gas generant 50, molded bodies of various shapes such as granular, pellet-like, cylindrical, and disc-like can be used. In addition, a perforated-shaped (e.g., hollow powder-like, lotus root-like, etc.) molded body having a through-hole can also be used as the molded body of the gas generant 50. These shapes are selected for the optimal shape according to the specifications of the pretensioner in which the gas generator 1 is assembled. In addition, in addition to the shape, the linear burning rate, pressure index, etc. are also taken into consideration to select the size, etc. of the molded body of the gas generant 50. In addition, the filling amount of the gas generant 50 can be appropriately changed according to the specifications of the assembled pretensioner, but in the case of using smokeless powder, it is generally set to about 0.1 g to 2.0 g.

[0069] As Figure 1 and Figure 3 shown, in the state where the cup 40 is assembled to the igniter assembly 2, as described above, the flange portion 43 of the cup 40 is set to be accommodated in the annular groove portion 2a of the igniter assembly 2, and the flange portion 43 is in a state of being sandwiched between the annular bead portion 13 and the bottom surface of the annular groove portion 2a. Here, a sealant 60 is sandwiched between the annular bead portion 13 and the annular groove portion 2a.

[0070] The sealant 60 is used to hermetically seal the accommodation space 44 in which the gas generant 50 is accommodated from the external space. Specifically, it is used to prevent the flow of gas through the interfaces between the retainer 10 and the cup 40 and between the retainer 10 and the resin molded portion 30.

[0071] Specifically, the sealant 60 is mainly positioned in a manner of filling the space defined by the bottom surface of the annular groove portion 2a defined by the first end surface 10a of the retainer 10, the lower side portion of the outer side wall surface of the annular groove portion 2a defined by the inner peripheral surface of the annular bead portion 13 of the retainer 10, the lower side portion of the inner side wall surface of the annular groove portion 2a defined by the outer peripheral surface of the first covering portion 31 of the resin molded portion 30, and the lower surface of the flange portion 43 of the cup 40. Thus, the sealant 60 is sandwiched between the retainer 10 and the cup 40 and covers the intersection line 2b between the first end surface 10a of the retainer 10 exposed inside the annular groove portion 2a and the outer peripheral surface of the first covering portion 31.

[0072] Here, as the sealant 60, any material can be used as long as it exhibits sealing performance after curing, but it is preferably moderately elastic after curing. For example, a material containing a silicone-based resin or a polyolefin-based resin as a raw material can be appropriately used.

[0073] The sealant 60 is applied in a liquid state to the inside of the annular groove portion 2a before caulking and fixing the flange portion 43 by means of the above-mentioned annular flange portion 13. By inserting the flange portion 43 into the annular groove portion 2a in this state and performing caulking and fixing of the flange portion 43 by means of the annular flange portion 13, it is formed to be sandwiched between the retainer 10, the resin molded portion 30, and the cup 40 in the above manner. In addition, the curing of the sealant 60 applied in a liquid state can be performed before or after caulking and fixing, but in order to ensure more reliable sealing performance brought by the sealant 60, it is preferably performed after caulking and fixing.

[0074] Figures 5 to 8 It is a schematic cross-sectional view showing a manufacturing method of the gas generator according to the present embodiment. Next, with reference to these Figures 5 to 8 , the manufacturing method of the gas generator 1 according to the present embodiment will be described.

[0075] When manufacturing the gas generator 1 according to the present embodiment, first, the retainer 10 is prepared. As described above, the retainer 10 is manufactured by performing forging, punching, and, if necessary, cutting on a plate-shaped metal part or a rod-shaped metal part used as a raw material in a predetermined order one or more times. Here, since the surface of the portion of the retainer 10 included in the gas generator 1 according to the present embodiment that is covered by the resin molded portion 30 does not have a complicated shape, high-precision cutting, which is the main cause of high cost, is not required.

[0076] Next, as Figure 5 (A) shows, the retainer 10 and the igniter 20 are placed in an injection molding die 200 composed of an upper die 201, a lower inner die 202A, and a lower outer die 202B. Specifically, the retainer 10 is placed on the lower outer die 202B of the lower inner die 202A and the lower outer die 202B in a pre-assembled state, and in this state, the igniter 20 is placed on the lower inner die 202A in such a manner that a pair of terminal pins 22 of the igniter 20 are inserted through the through-hole portion 10c of the retainer 10. Then, the upper die 201 is combined with the lower inner die 202A and the lower outer die 202B so as to cover the retainer 10 and the igniter 20. Thus, a cavity 203 having a shape corresponding to the resin molded portion 30 is formed around the retainer 10 and the igniter 20 located inside the die 200.

[0077] Next, as Figure 5As shown in (B), the resin molded part 30 is formed by injection molding. Specifically, an insulating fluid resin material is injected from the gate 201a provided in the upper mold 201 toward the cavity 203, and thus the cavity 203 is filled with the fluid resin material. Then, by curing the fluid resin material filled in the cavity 203, it is fixed to the surfaces of the retainer 10 and the igniter 20, and thus the resin molded part 30 that fixes the retainer 10 and the igniter 20 to each other is formed.

[0078] Here, from the viewpoint of improving the moldability of the resin molded part 30, it is important that the fluid resin material injected into the cavity 203 flows into each corner of the cavity 203. In particular, in the case where no measures are taken, due to the structure of the resin molded part 30, the flow of the fluid resin material may be blocked at a position corresponding to the portion that covers the second end face 10b of the retainer 10 in the resin molded part 30 (i.e., the first portion 32a of the second covering portion 32), and the portion of the resin molded part 30 that covers the second end face 10b of the retainer 10 is the portion where the cross-sectional area of the cavity 203 in the direction orthogonal to the flow direction of the fluid resin material is the smallest.

[0079] In this regard, in the gas generator 1 according to the present embodiment, as described above, on the surface of the concave portion 14 of the retainer 10, a plurality of groove portions 14a are provided so as to reach the second end face 10b of the portion where the concave portion 14 is not provided from the through hole 10c provided in the partition portion 12. Therefore, the cross-sectional area of the cavity 203 in the region facing the portion where the plurality of groove portions 14a are provided is configured to be larger than the cross-sectional area of the cavity 203 in the region facing the portion where the plurality of groove portions 14a are not provided. That is, the cavity 203 in the region facing the portion where the plurality of groove portions 14a are not provided is configured as a narrow path 203a through which the fluid resin material flows, and in contrast, the cavity 203 in the region facing the portion where the plurality of groove portions 14a are provided is configured as a wide path 203b through which the fluid resin material flows.

[0080] Therefore, by providing the wide path 203b through which the fluid resin material flows in a part of the portion where the cross-sectional area of the cavity 203 in the direction orthogonal to the flow direction of the fluid resin material is the smallest in this way, the diffusion of the fluid resin material in the cavity 203 is improved, and by the fluid resin material reaching each corner of the cavity 203, the moldability of the resin molded part 30 is remarkably improved.

[0081] In addition, in the gas generator 1 according to the present embodiment, by satisfying the protruding length A of the second portion 32b of the second covering portion 32, the axial length B of the retainer 10 in the state where the cup 40 is assembled to the retainer 10, and the depth C of the female connector portion 32c as described above (all refer to Figure 1)Satisfying the above first condition (i.e., the condition that B < 1.8×A) and / or the second condition (i.e., the condition that C < 1.8×A), the protruding length A of the second part 32b of the second covering portion 32 is formed to be significantly long.

[0082] Therefore, corresponding to the long amount of the protruding length A of the second part 32b of the second covering portion 32, the length of the narrow path 203a also naturally becomes shorter. So in this regard, the diffusion of the fluid resin material in the cavity 203 is also improved, and the formability of the resin molding portion 30 is remarkably enhanced.

[0083] Next, the igniter assembly 2 composed of the retainer 10, the igniter 20, and the resin molding portion 30 fabricated by forming the resin molding portion 30 is taken out from the mold 200, and then, as Figure 6 shown, the application of the sealant 60 is performed. Specifically, for example, the liquid sealant 60 is applied to the annular groove portion 2a of the igniter assembly 2 defined by the outer peripheral surface of the first covering portion 31 of the resin molding portion 30, the first end surface 10a of the retainer 10, and the inner peripheral surface of the annular flange portion 13 of the retainer 10 by using a dispenser 210. At this time, the liquid sealant 60 is applied in an amount sufficient to cover the boundary line 2b between the first end surface 10a of the retainer 10 exposed inside the annular groove portion 2a and the outer peripheral surface of the first covering portion 31 after curing.

[0084] Next, as Figure 7 and Figure 8 shown, the assembly of the cup 40 to the igniter assembly 2 is performed. Specifically, first, as Figure 7 shown, the flange portion 43 of the cup 40 containing a predetermined amount of the gas generating agent 50 inside is inserted into the annular groove portion 2a of the igniter assembly 2 where the liquid sealant 60 has been applied to the inside of the annular groove portion 2a. Next, as Figure 8 shown, while maintaining the state where the flange portion 43 is received in the annular groove portion 2a, the annular flange portion 13 provided on the retainer 10 is bent inward (i.e., in the direction of the arrow D shown in the figure), and caulking fixation of the flange portion 43 is performed by means of the annular flange portion 13.

[0085] Thereby, in a state where the boundary line 2b (refer to Figure 3 ) between the first end surface 10a of the retainer 10 exposed inside the annular groove portion 2a and the outer peripheral surface of the first covering portion 31 of the resin molding portion 30 is covered by the sealant 60, the flange portion 43 is clamped between the annular flange portion 13 and the bottom surface of the annular groove portion 2a, and thereby the cup 40 is assembled to the igniter assembly 2.

[0086] As described above, the curing of the sealant 60 is performed before or after the caulking fixation of the flange portion 43 by means of the annular flange portion 13, therebyFigure 1 The manufacturing of the gas generator 1 as shown is completed. In addition, since the sealant 60 not only covers the above-mentioned junction line 2b but is also sandwiched between the retainer 10 and the cup 40, airtightness can be ensured in both the portion between the retainer 10 and the cup 40 and the portion between the retainer 10 and the resin molded portion 30 by means of this sealant 60.

[0087] As described above, by forming the gas generator 1 according to the present embodiment, not only can the airtightness be reliably ensured for a long time at the interface between the resin molded portion 30 and the retainer 10 by means of the sealant 60, but also a gas generator that can be manufactured inexpensively without high-precision machining can be formed.

[0088] Figure 9 (A) and Figure 9 (B) are schematic cross-sectional views showing an example and another example of the state in which the gas generator according to the present embodiment is installed in the pretensioner. Next, with reference to these Figure 9 (A) and Figure 9 (B), the assembly structure of the gas generator 1 according to the present embodiment to the pretensioner will be described.

[0089] As Figure 9 (A) shows, when the gas generator 1 is installed in the pretensioner 100A provided in the seat belt device, the gas generator 1 is assembled to the substantially cylindrical housing 110 of the pretensioner 100A.

[0090] More specifically, first, the gas generator 1 is inserted into the interior of the housing 110 from the axial end on the side where the cup 40 is located. At this time, the upper end of the annular flange portion 13 of the retainer 10 provided on the gas generator 1 abuts against the stepped portion 111 provided on the inner peripheral surface of the housing 110, and the gas generator 1 is positioned relative to the housing 110. In the state where this positioning has been performed, the second part 32b of the second covering portion 32 in the resin molded portion 30 of the gas generator 1 faces the front end side portion of the housing 110 in the radial direction of the housing 110.

[0091] Next, in this state, by bending the front end side portion of the housing 110 inward (i.e., toward the second part 32b side of the second covering portion 32 of the gas generator 1), the body portion 11 of the retainer 10 of the gas generator 1 is clamped by the bent portion of the housing 110, that is, the caulking portion 112 and the above-mentioned stepped portion 111, and thus the gas generator 1 is caulked and fixed relative to the housing 110.

[0092] With the above, the gas generator 1 is assembled to the pretensioner 100A. In a state where the gas generator 1 is assembled to the pretensioner 100A, the second part 32b of the second covering portion 32 of the gas generator 1 protrudes from the front end of the housing 110. Therefore, by the second part 32b of the second covering portion 32 serving as a guiding portion, the insertion of the male connector into the female connector portion 32c provided in the second covering portion 32 can be performed more easily.

[0093] On the other hand, in Figure 9 In the pretensioner 100B shown in (B), for the purpose of improving its pressure resistance performance, the thickness of the housing 110 is configured to be larger than the thickness of the above-mentioned pretensioner 100A. In this case, as the thickness of the housing 110 increases, the thickness of the caulking portion 112, which is the portion for caulking and fixing the gas generator 1, also becomes larger. When the protruding amount of the second part 32b of the second covering portion 32 of the gas generator 1 is not sufficiently large, the second part 32b of the second covering portion 32 of the gas generator 1 does not protrude from the front end of the housing 110, and the above-mentioned guiding function is not exerted.

[0094] In this regard, in the gas generator 1 according to the present embodiment, by the protruding length A of the second part 32b of the second covering portion 32, the axial length B of the retainer 10 in a state where the cup 40 is assembled to the retainer 10, and the depth C of the female connector portion 32c (all refer to Figure 1 ) satisfying the above-mentioned first condition (that is, the condition of B < 1.8×A) and / or the second condition (that is, the condition of C < 1.8×A), the protruding length A of the second part 32b of the second covering portion 32 is configured to be significantly long.

[0095] Therefore, the protruding amount of the second part 32b of the second covering portion 32 is sufficiently ensured, and even when the thickness of the housing 110 increases, the guiding function brought by the second part 32b of the second covering portion 32 is not lost, and the effect of facilitating the insertion of the male connector can be obtained.

[0096] In addition to the above, referring to Figure 9 (A) and Figure 9 (B), when a higher gas output is required, although it is effective to increase the axial length of the cup 40 in order to increase the amount of the gas generating agent 50 filled in the gas generator 1, in such a configuration, the insertion amount of the gas generator 1 into the housing 110 also necessarily becomes larger. In order to ensure the internal volume of the housing 110 of the portion where the gas generator 1 is not inserted, as a result, there is a need to increase the housing 110 accordingly, and the problem of the enlargement of the pretensioners 100A and 100B arises.

[0097] In this regard, in the gas generator 1 according to the present embodiment, by satisfying the above-described first condition and / or second condition, the protruding length A of the second portion 32b of the second covering portion 32 is ensured to be significantly long, so that the female connector portion 32c can be retracted along the axial direction of the gas generator 1 in a direction farther from the cup 40, and accordingly, the resin molding portion 30, the partition portion 12 of the retainer 10, and the igniter 20 can also be retracted in a direction farther from the cup 40.

[0098] Therefore, even if the axial length of the cup 40 is not increased, the volume of the accommodation space 44 is increased corresponding to the amount by which these resin molding portion 30, the partition portion 12 of the retainer 10, and the igniter 20 are retracted, and accordingly, the filling amount of the gas generating agent 50 can be increased. Thus, by adopting this structure, in the case where higher gas output is required, it can be achieved without increasing the size of the pretensioners 100A and 100B.

[0099] Figure 10 FIG. is a schematic cross-sectional view showing a method of attaching a short-circuit clip to the gas generator according to the present embodiment. Next, with reference to this Figure 10 FIG., a method of attaching a short-circuit clip 80 to the gas generator 1 according to the present embodiment will be described.

[0100] In the gas generator 1 according to the present embodiment, it is necessary to prevent in advance a malfunction such as that caused by electrostatic discharge before mounting on a vehicle. As Figure 10 shown, the short-circuit clip 80 is a component that is attached to the female connector portion 32c of the gas generator 1 to prevent such a malfunction. In a state where the short-circuit clip 80 is attached to the female connector portion 32c, a pair of terminal pins 22 of the igniter are intentionally short-circuited by a conductive leaf spring portion (not shown) provided in the short-circuit clip 80.

[0101] When the short-circuit clip 80 is attached to the gas generator 1, the short-circuit clip 80 is inserted into the female connector portion 32c of the gas generator 1. At this time, a plurality of engaged portions 81 provided on the circumferential surface of the short-circuit clip 80 are engaged by an engaging portion 32b1 provided on the inner side surface of the female connector portion 32c. By the engagement of the engaged portion 81 by the engaging portion 32b1, the short-circuit clip 80 is fixed to the female connector portion 32c.

[0102] In addition, in the short-circuit clip 80, a hollow portion (not shown) for receiving a pair of terminal pins 22 of the igniter 20 is provided, and the above-described leaf spring portion is disposed in the hollow portion. The leaf spring portion is configured to be able to contact both of the pair of terminal pins 22 while elastically applying force thereto in a state where the short-circuit clip 80 is fixed to the female connector portion 32c, thereby maintaining the state in which the pair of terminal pins 22 are short-circuited.

[0103] Here, in the gas generator 1 according to the present embodiment, by satisfying the above-mentioned first condition and / or second condition, the protruding length A of the second part 32b of the second covering portion 32 (refer to Figure 1 ) is ensured to be significantly long, so the locking portion 32b1 provided in the gas generator 1 is provided in the portion defined by the second part 32b on the inner side surface of the female connector portion 32c.

[0104] Next, referring to the foregoing Figure 1 , the operation of the gas generator 1 according to the present embodiment during operation will be described.

[0105] Referring to Figure 1 , when a vehicle equipped with the gas generator 1 according to the present embodiment collides, the collision is detected by a separately provided collision detection mechanism in the vehicle, and the igniter 20 operates by energization from the control unit based on it. By the operation of the igniter 20, the ignition charge housed in the ignition portion 21 is ignited and burned, whereby the detonator cup cracks.

[0106] By means of the cracking of the detonator cup, the flame generated by the burning of the ignition charge is ejected toward the accommodation space 44 that houses the gas generant 50. By means of this flame, the gas generant 50 is ignited and burned, and a large amount of gas is generated in the accommodation space 44. By means of the burning of the gas generant 50, the internal pressure of the accommodation space 44 rises rapidly, whereby the bottom wall portion 42 of the cup 40 opens starting from the notch 42a, and the large amount of gas generated is led to the outside of the gas generator 1.

[0107] Then, the large amount of gas led out from the gas generator 1 is guided to the operation space of the pretensioner in which the gas generator 1 is installed (that is, the space inside the above-mentioned housing 110 (refer to Figure 9 (A) and Figure 9 (B), etc.). Thereby, the pretensioner is driven, and one end of the seat belt provided in the seat belt device is strongly pulled in.

[0108] If the characteristic structure of the gas generator disclosed in the above embodiment is summarized, it becomes as follows.

[0109] [Supplementary Note 1]

[0110] A gas generator includes: a gas generating agent that generates gas by combustion; a bottomed substantially cylindrical cup that houses the gas generating agent and has one axial end configured as an open end; and an igniter assembly having a substantially cylindrical outer shape and closing the open end of the cup by coaxially assembling the cup. The igniter assembly includes: an igniter having an ignition portion filled with an igniting powder and a terminal pin connected to the ignition portion; a substantially cylindrical metal holder having a first end face as an axial end face on the side facing the cup, a second end face as an axial end face on the side not facing the cup, and a through hole reaching the first end face and the second end face and through which at least a part of the igniter is inserted; and a resin molding portion that fills the space between the igniter and the holder to fix the igniter to the holder such that the ignition portion faces the gas generating agent. A protruding annular flange portion is provided on the first end face of the holder so as to surround the through hole. The resin molding portion has a first covering portion that adheres to and covers a portion of the first end face of the holder around the through hole, a second covering portion that adheres to and covers a portion of the second end face of the holder around the through hole, and a connecting portion that connects the first covering portion and the second covering portion by filling the through hole. The cup has a flange portion extending outward from the open end. An annular groove portion for receiving the flange portion is provided on the axial end face of the igniter assembly on the side facing the cup. The inner wall surface of the annular groove portion is defined by the outer peripheral surface of the first covering portion. The bottom surface of the annular groove portion is defined by the first end face of the holder. The outer wall surface of the annular groove portion is defined by the inner peripheral surface of the annular flange portion. By bending the annular flange portion inward in a state where a sealant is applied to the inside of the annular groove portion and the flange portion is received in the annular groove portion, the flange portion is sandwiched between the annular flange portion and the bottom surface of the annular groove portion in a state where the sealant covers the intersection line between the first end face of the holder exposed inside the annular groove portion and the outer peripheral surface of the first covering portion, whereby the cup is assembled to the holder.

[0111] [Appendix 2]

[0112] The gas generator as described in Attachment 1 is provided, on the second end face of the retainer, with a recess communicating with the through portion; the second covering portion is configured to include a first portion that covers the recess and a second portion that protrudes from the second end face of the retainer at a portion where the recess is not provided toward the side opposite to the side where the cup is located; a concave female connector portion is provided across the first portion and the second portion of the second covering portion, and the female connector portion is for arranging the terminal pin and for receiving and holding a male connector, and the male connector is for external connection of the igniter via the terminal pin.

[0113] [Attachment 3]

[0114] In the case of the gas generator as described in Attachment 2, when the protruding length of the second portion is set as A and the axial length of the retainer in a state where the cup is assembled to the retainer is set as B, the condition of B < 1.8×A is satisfied.

[0115] [Attachment 4]

[0116] In the case of the gas generator as described in Attachment 2, when the protruding length of the second portion is set as A and the depth of the female connector portion is set as C, the condition of C < 1.8×A is satisfied.

[0117] [Attachment 5]

[0118] In the gas generator as described in any one of Attachments 2 to 4, a locking portion having a recessed shape for holding a short - circuit clip is provided at a portion of the inner side surface of the female connector portion defined by the second portion.

[0119] [Attachment 6]

[0120] In the gas generator as described in any one of Attachments 2 to 5, a groove portion is provided on the surface of the recess, and the groove portion extends from the through portion to the second end face of the retainer at a portion where the recess is not provided; the groove portion is filled by the second covering portion.

[0121] In addition, in the above - described embodiment, the case where the gas generator is manufactured in an order of applying a sealant to the inside of the annular groove portion in advance before caulking the annular flange portion is illustrated, but it is also possible not to apply the sealant to the inside of the annular groove portion in advance before caulking the annular flange portion and only apply the sealant to the flange portion of the cup in advance, or it is also possible to apply the sealant to both the inside of the annular groove portion and the flange portion before caulking the annular flange portion.

[0122] In addition, as long as it does not deviate from the gist of the present invention, the shapes, structures, sizes, quantities, materials, etc. of the respective portions shown in the above - described embodiment can be appropriately changed.

[0123] Thus, the above-described embodiments disclosed herein are illustrative in all aspects and not restrictive. The technical scope of the present invention is defined by the claims, and includes all changes within the meaning and scope equivalent to the description of the claims.

[0124] Description of Reference Numerals

[0125] 1 Gas generator; 2 Igniter assembly; 2a Annular groove portion; 2b Junction line; 10 Holder; 10a First end face; 10b Second end face; 10c Through portion; 11 Body portion; 12 Partition portion; 13 Annular flange portion; 14 Recess; 14a Groove portion; 20 Igniter; 21 Ignition portion; 22 Terminal pin; 30 Resin molding portion; 31 First covering portion; 31a Reinforcing portion; 32 Second covering portion; 32a First part; 32b Second part; 32b1 Locking portion; 32c Female connector portion; 33 Connecting portion; 40 Cup; 41 Side wall portion; 41a Open end; 42 Bottom wall portion; 42a Score; 43 Flange portion; 44 Receiving space; 50 Gas generating agent; 60 Sealing agent; 80 Short circuit clip; 81 Portion to be locked; 100A, 100B Pretensioner; 110 Housing; 111 Step portion; 112 Caulked portion; 200 Mold; 201 Upper mold; 201a Gate; 202A Lower inner mold; 202B Lower outer mold; 203 Cavity; 203a Narrow path; 203b Wide path; 210 Distributor.

Claims

1. A gas generator, characterized in that it comprises: a gas generant that generates gas by combustion; a bottomed substantially cylindrical cup that houses the aforementioned gas generant and has one axial end configured as an open end; and an igniter assembly having a substantially cylindrical outer shape and closing the aforementioned open end of the aforementioned cup by coaxially assembling the aforementioned cup; the aforementioned igniter assembly includes: an igniter having an ignition portion filled with an igniting powder and a terminal pin connected to the ignition portion; a substantially cylindrical metal holder having a first end face as an axial end face on the side facing the aforementioned cup, a second end face as an axial end face on the side not facing the aforementioned cup, and a through portion reaching the aforementioned first end face and the aforementioned second end face and through which at least a part of the aforementioned igniter is inserted; and a resin molding portion that fills the space between the aforementioned igniter and the aforementioned holder to fix the aforementioned igniter to the aforementioned holder so that the aforementioned ignition portion faces the aforementioned gas generant; on the aforementioned first end face of the aforementioned holder, a protruding annular flange portion is provided so as to surround the aforementioned through portion; the aforementioned resin molding portion has a first covering portion that adheres to and covers a portion of the aforementioned first end face of the aforementioned holder located around the aforementioned through portion, a second covering portion that adheres to and covers a portion of the aforementioned second end face of the aforementioned holder located around the aforementioned through portion, and a connecting portion that connects the aforementioned first covering portion and the aforementioned second covering portion by filling the aforementioned through portion; the aforementioned cup has a flange portion extending outward from the aforementioned open end; on the axial end face of the aforementioned igniter assembly on the side facing the aforementioned cup, an annular groove portion for receiving the aforementioned flange portion is provided; the inner wall surface of the aforementioned annular groove portion is defined by the outer peripheral surface of the aforementioned first covering portion; the bottom surface of the aforementioned annular groove portion is defined by the aforementioned first end face of the aforementioned holder; the outer wall surface of the aforementioned annular groove portion is defined by the inner peripheral surface of the aforementioned annular flange portion; by bending the aforementioned annular flange portion inward in a state where a sealant is applied to the inside of the aforementioned annular groove portion and the aforementioned flange portion is received in the aforementioned annular groove portion, the flange portion is sandwiched between the aforementioned annular flange portion and the bottom surface of the aforementioned annular groove portion in a state where the sealant covers the boundary line between the aforementioned first end face of the aforementioned holder exposed inside the aforementioned annular groove portion and the outer peripheral surface of the aforementioned first covering portion, whereby the aforementioned cup is assembled to the aforementioned holder.

2. The gas generator according to claim 1, characterized in that on the aforementioned second end face of the aforementioned holder, a recess communicating with the aforementioned through portion is provided; the aforementioned second covering portion is provided to include a first portion that covers the aforementioned recess and a second portion that protrudes from the aforementioned second end face of the aforementioned holder at a portion where the aforementioned recess is not provided toward the side opposite to the side where the aforementioned cup is located; A concave female connector portion is provided across the first part and the second part of the second covering portion. The female connector portion is for arranging the terminal pins and is used to receive and hold a male connector, and the male connector is used for external connection of the igniter via the terminal pins.

3. The gas generator according to claim 2, wherein when the protruding length of the second part is set as A and the axial length of the retainer in the state where the cup is assembled to the retainer is set as B, the condition B < 1.8 × A is satisfied.

4. The gas generator according to claim 2, wherein when the protruding length of the second part is set as A and the depth of the female connector portion is set as C, the condition C < 1.8 × A is satisfied.

5. The gas generator according to any one of claims 2 to 4, wherein a locking portion having a recessed shape for holding a short-circuit clip is provided in a portion of the inner side surface of the female connector portion defined by the second part.

6. The gas generator according to any one of claims 2 to 4, wherein a groove portion is provided on the surface of the recess, and the groove portion reaches the second end surface of the retainer at a portion where the recess is not provided from the through portion; the groove portion is filled with the second covering portion.

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