Igniter assembly and method for assembling the igniter assembly

Abstract

An igniter assembly (1) comprising: an igniter (2) of the electric ignition type, which includes, an ignition section (3) containing an ignition means, a holding portion (4) made of resin, covering at least a portion of the periphery of the ignition portion (3) and holding the ignition portion (3), and an electrically conductive pin (5) configured to energize the ignition section (3); and a detonator collar (6) made of metal and to which the detonator (2) is attached, wherein the igniter collar (6) includes a fixing portion (60) surrounding the holding portion (4) to fix the holding portion (4), the holding portion (4) includes a projection portion (44, 44a, 44b) formed continuously around a circumference thereof and formed integrally with the holding portion (4), and the projection portion (44, 44a, 44b) is press-connected to the fixing portion (60), in a state in which the holding portion (4) is fixed to the fixing portion (60), characterized in that in a state in which the holding portion (4) is fixed to the fixing portion (60), the projection portion (44, 44a, 44b) is pressed and deformed against the fixing portion (60), a tip end of the projection portion (44, 44a, 44b) is squeezed and deformed to be in airtight close contact with the fixing portion (60).

Description

[0001] The present disclosure relates to an igniter assembly according to the preamble of independent claim 1, which comprises an igniter of an electric ignition type attached to an igniter collar, and also relates to a method of assembling an igniter assembly according to the preamble of independent claim 8. Such an igniter assembly and such a method of assembling an igniter assembly can be found in JP 2008-062 685 A and JP 2018-158 690 A, respectively.

[0002] An igniter assembly containing an electric ignition-type igniter is assembled so that this igniter is fixed to a igniter collar made of metal. Additionally, the igniter assembly is attached to a safety device such as an airbag inflator via an igniter collar and is widely used. With such a safety device, it is important to ensure that the igniter is triggered when needed and that the device in which the igniter is installed functions safely. In a case where the igniter assembly has poor sealing properties between the igniter and the igniter collar, atmospheric moisture from the outside of the igniter assembly penetrates into the device through a small gap (for example, a gap between the igniter and the igniter collar) in the igniter assembly, which may cause a defect.In this regard, Patent Document 1 discloses a technique for improving sealing properties in an igniter assembly, in which a groove is formed in an inner peripheral surface of a tubular collar member surrounding the igniter, and the igniter is fixed to the tubular collar member in a state where a sealing member is fitted into this groove and pressed together with the igniter.

[0003] Additionally, Patent Document 2 describes an igniter assembly including an igniter main body including an igniting portion and a resin portion surrounding a periphery of the igniting portion, as well as an igniter collar to which the igniter main body is attached and fixed. In the igniter assembly, a protrusion formed on the inner peripheral portion of the igniter collar engages the resin portion, thereby improving the sealing properties of the igniter assembly. Citation listPatent documents Patent Document 1: JP H11-59314 A Patent Document 2: JP 2007-225160 A

[0004] Using a sealing element to improve the sealing properties in the igniter assembly increases the number of parts in the igniter assembly. This increase in the number of parts is undesirable from a parts management perspective. The number of assembly steps also increases.

[0005] Furthermore, once the protrusion formed on the inner peripheral portion of the metal igniter collar is pressed into the resin portion, the portion of the resin portion into which the protrusion is pressed will be deformed and depressed. When the igniter is reattached to the igniter collar, the deformation of the resin portion will deteriorate the sealing properties. Therefore, the igniter collar attachment process cannot be repeated. Since the igniter collar attachment process cannot be repeated in this way, the igniter collar and the igniter must be precisely aligned. This makes the igniter collar attachment difficult.

[0006] In view of the problem described above, the object of the present invention is to provide an igniter assembly and a method for assembling an igniter assembly that improves a sealing property in an igniter assembly without increasing the number of parts, while simultaneously facilitating assembly. This object is achieved according to the invention by an igniter assembly having the features of independent patent claim 1. Furthermore, this object is achieved according to the invention by a method for assembling an igniter assembly having the features of independent patent claim 8. Preferred developments are set out in the subclaims.

[0007] Accordingly, in the present disclosure, a resin-made holding portion includes a protrusion, and the protrusion is press-fitted to a fixing portion of an igniter collar. This makes it possible to improve the sealing properties in an igniter assembly without increasing the number of parts, while also facilitating assembly.

[0008] In particular, the present disclosure provides an igniter assembly including an electric ignition type igniter having an ignition portion with an ignition means;a holding portion made of resin that covers at least a portion of a periphery of the ignition portion and holds the ignition portion and an electroconductive pin configured to energize the ignition portion, and also includes an igniter collar made of metal to which the igniter is attached, in which the igniter collar includes a fixing portion surrounding the holding portion to fix the holding portion, the holding portion having a protrusion portion continuously formed around a periphery thereof and integrally formed with the holding portion, and the protrusion portion being press-fitted to the fixing portion in a state where the holding portion is fixed to the fixing portion;

[0009] In the igniter assembly described above, the protrusion portion included in the resin-made holding portion is press-fitted to the metal-made fixing portion of the igniter collar. This makes it possible to improve the sealing property between the igniter and the igniter collar to prevent moisture penetration from the outside. Furthermore, the protrusion portion is made of resin and is integrally formed with the holding portion. This makes it possible to improve the sealing property of the igniter assembly without using a sealing member such as a gasket. Furthermore, there may be a case where a process for fixing the igniter holding portion to the fixing portion of the igniter collar needs to be performed again.In such a case, even if the holding portion has been detached from the fixing portion once, the protrusion portion can be press-fitted to the fixing portion when the holding portion is reattached to the fixing portion. This ensures the sealing performance of the igniter assembly even if this process is repeated. Thus, this igniter assembly can improve the sealing performance without increasing the number of parts, while maintaining ease of assembly.

[0010] In the igniter assembly described above, in a state where the holding portion is fixed to the fixing portion, the protrusion portion can be pressed and deformed against the fixing portion to be brought into airtight, close contact with the fixing portion. At this time, a tip end of the protrusion is squeezed and deformed to be brought into airtight, close contact with the fixing portion, thereby further improving the sealing properties between the igniter and the igniter collar.

[0011] The igniter assembly described above may be configured such that the igniter portion includes a tube peripheral wall portion, a lid portion closing one end of the tube peripheral wall portion, and a receiving space formed with the tube peripheral wall portion and the lid portion and receiving the igniting agent therein, wherein the lid portion is arranged such that the lid portion is located on a side toward which a combustion product of the igniting agent will leak when the igniter is actuated, wherein the holding portion includes: a slant portion inclined downward from the igniter assembly and surrounding at least a portion of a periphery of the tube peripheral wall portion and crimped to a tip end portion of the fixing portion, an opposing portion opposite to a bottom surface portion of the fixing portion, and a Peripheral wall section,which connects the inclined portion and the opposite portion, the protrusion portion is formed on at least one of the inclined portion, the peripheral wall portion, or the opposite portion, and the fixing portion surrounds at least a portion of the inclined portion, the peripheral wall portion, and the opposite portion to fix the holding portion.

[0012] Here, the protrusion may be formed on at least one of the inclined portion, the peripheral wall portion, or the opposing portion of the holding portion. In a state where the holding portion is fixed to the fixing portion, the protrusion portion may be formed at a position that allows the protrusion portion to be press-fixed to the fixing portion of the igniter collar. By press-fixing the protrusion portion to the fixing portion, the sealing property of the igniter assembly can be improved and the intrusion of moisture from the outside can be prevented.

[0013] The igniter assembly may be configured such that a plurality of protrusion portions are formed on the holding portion, wherein the plurality of protrusion portions include a first protrusion portion and a second protrusion portion, and the first protrusion portion and the second protrusion portion are formed concentrically with respect to a central axis of the igniter portion and have different heights protruding from the holding portion. The first protrusion portion and the second protrusion portion, which are formed concentrically with respect to the central axis of the igniter portion, are formed such that the heights of these portions differ from each other.Thus, even in a case where a process for fixing the holding portion of the igniter to the fixing portion of the igniter collar must be repeated, the shorter protrusion portion is not brought into contact with the fixing portion, or only its tip end is brought into contact with the fixing portion at the time of initially fixing the holding portion to the fixing portion, while the taller protrusion portion is press-fitted and deformed in a squashed manner. This prevents the shorter protrusion portion from being deformed to the point of being completely crushed. Thus, when the holding portion is reattached to the fixing portion, the undeformed protrusion can be reliably pressed and deformed against the fixing portion.With this configuration, the igniter assembly described above can ensure the sealing property even if the process of fixing the holding section to the fixing section is performed again.

[0014] The igniter assembly may be configured such that the cross-sectional shape of the protruding portion in a direction in which it protrudes from the surface of the holding portion is rectangular, trapezoidal, or semicircular, and such that the width of the cross-sectional shape is greater than the height of the protrusion from the front surface. Thus, the cross-sectional shape of the protruding portion may be rectangular, trapezoidal, or semicircular. Furthermore, the cross-sectional shape of the protruding portion may be triangular or another polygonal shape.

[0015] The igniter assembly described above may be configured such that the fixing portion includes a groove portion formed at a position corresponding to the protrusion portion. In a case where the protrusion portion is press-fixed to the fixing portion, the protrusion portion is fitted into the groove portion and deformed into a shape corresponding to a shape of the groove portion. By fitting the protrusion portion into the groove portion and deforming it into a shape corresponding to the groove portion, the sealing property between the igniter and the igniter collar is further improved.

[0016] Here, the present disclosure can be viewed from the aspect of a method for assembling an igniter assembly. That is, the present disclosure can provide a method for assembling an igniter assembly in which an electric ignition type igniter is attached to a metal igniter collar, the method including: manufacturing the igniter including an ignition portion containing an ignition means, a holding portion made of resin that covers at least a portion of a periphery of the ignition portion and holds the ignition portion, and an electrically conductive pin configured to energize the ignition portion;and manufacturing the igniter collar including a fixing portion surrounding the holding portion to fix it, wherein the holding portion includes a protrusion portion formed continuously around a periphery thereof and formed integrally with the holding portion, and wherein the method of assembling an igniter assembly further includes fixing the holding portion to the fixing portion in a state where the protrusion portion is press-fitted to the fixing portion.; Advantageous effects of the invention

[0017] With the technique according to the present disclosure, the sealing property in the igniter assembly can be improved without increasing the number of parts, while the assembly can be easily performed. Brief description of the drawings Fig. 1 is a diagram showing a schematic configuration of a gas generator with an igniter assembly according to a first embodiment. Fig. 2 is a diagram showing a schematic configuration of the igniter assembly according to the first embodiment. Fig. 3 is a flowchart for a method of assembling an igniter assembly according to the first embodiment. Fig. 4 is a diagram showing a schematic configuration of an igniter of the igniter assembly according to the first embodiment. Fig. 5 is a diagram showing a schematic configuration of an igniter collar of the igniter assembly according to the first embodiment. Fig. 6 is a diagram showing a schematic configuration of an igniter assembly according to a first modified example of the first embodiment. Fig. 7 is a diagram (No. 1) showing a schematic configuration of an igniter assembly according to a second modified example of the first embodiment. Fig. 8 is a diagram (No. 2) showing a schematic configuration of the igniter assembly according to the second modified example of the first embodiment. Fig. 9 is a diagram (No. 3) showing a schematic configuration of the igniter assembly according to the second modified example of the first embodiment. Fig. 10 is a diagram (No. 1) showing a schematic configuration of an igniter assembly according to a third modified example of the first embodiment. Fig. 11 is a diagram (No. 2) showing a schematic configuration of an igniter assembly according to the third modified example of the first embodiment. Fig. 12 is a diagram showing a schematic configuration of an igniter assembly according to a second embodiment. Fig. 13 is a diagram showing a method of assembling an igniter assembly according to the second embodiment. Description of implementation examples

[0018] Hereinafter, an igniter assembly and a method of assembling an igniter assembly according to an embodiment of the present disclosure will be described with reference to the drawings. It should be noted that each of the configurations, combinations thereof, and the like in each embodiment is an example, and additions, omissions, substitutions, and other changes to the configuration can be made as needed without departing from the spirit of the present invention. The present disclosure is not limited by the embodiments and is limited only by the claims. First embodiment

[0019] Fig. 1 is an axial cross-sectional view of an airbag gas generator (hereinafter referred to as a "gas generator") 100 using an igniter assembly 1 according to a first embodiment. Note that the gas generator 100 is not limited to a gas generator for an airbag and may have a known shape suitable for a seatbelt pretensioner or a curtain airbag, or may have a known shape used for various types of actuators or the like. The gas generator 100 includes an upper shell 101 and a lower shell 102. The upper shell 101 and the lower shell 102 are made of metal and have a substantially cylindrical shape with a bottom. Furthermore, a plurality of gas discharge ports 104 are formed circumferentially adjacent to each other in the upper shell 101.In the gas generator 100, the upper shell 101 and the lower shell 102 are joined in a state where the open ends of these shells are opposed to each other to form a casing 103 having a short tubular shape with both ends closed in the axial direction. The igniter assembly 1 is disposed in this casing 103. Note that, before the igniter assembly 1 is actuated, the gas discharge port 104 is sealed from the inside of the casing 103 with an aluminum sealing tape 114. The igniter assembly 1, which will be described in detail later, generates combustion gas to inflate, for example, an airbag, using an igniter 2 included in the igniter assembly 1 (see FIG. Fig. 2) is actuated to cause the ignition and combustion of a gas generating agent 105 with which the housing 103 is filled.

[0020] In the gas generator 100, an inner tube member 108, which includes a peripheral wall with a plurality of flame transmission holes 107, is arranged in the center of the housing 103. Additionally, a space 109 for accommodating the igniter assembly 1 and the transmission charge 111 is formed within the inner tube member 108. Furthermore, a combustion chamber 110 for accommodating the gas generating agent 105 is formed outside the inner tube member 108 in the radial direction. It should be noted that the gas generating agent 105 is supported in the combustion chamber 110 by a sub-plate 115 having a substantially annular shape. A gas generating agent with favorable ignitability and a combustion temperature higher than that of the gas generating agent 105 can be used as the transfer charge 111. Preferably, the combustion temperature of the transfer charge 111 is in the range of 1,700°C to 3,000°C.A known material containing, for example, nitroguanidine (34 wt%) and strontium nitrate (56 wt%) can be used as the transfer charge 111. Alternatively, a known black powder (boron nitrate) can also be used as the transfer charge. Furthermore, a gas generating agent with a relatively low combustion temperature can be used for the gas generating agent 105. It is desirable that the combustion temperature of the gas generating agent 105 be in a range of, for example, 1000°C to 1700°C. A known material containing guanidine nitrate (41 wt%), base copper nitrate (49 wt%), a binder, and an additive can be used.

[0021] In addition, the igniter assembly 1 is attached to the lower shell 102 side of the inner tube element 108. The igniter assembly 1 can be attached to the inner tube element 108 such that the open-end portion 112 of the inner tube element 108 is crimped to form an igniter collar 6 (see Fig. 2) to fix the igniter assembly 1. Furthermore, the inner tube member 108 is connected by welding or the like to the lower shell 102 near the open-end portion 112 on one side where the igniter assembly 1 is housed.

[0022] The gas generating agent 105 is housed in the combustion chamber 110, and a filter 106 is disposed on the outside thereof. The filter 106 collects a combustion residue contained in the combustion gas generated by the combustion of the gas generating agent 105 and cools the combustion gas. The filter 106 is formed into a tubular shape using a laminated metal mesh or the like and has an outer peripheral surface facing an inner peripheral surface of the casing 103. A gap 113, which serves as a gas flow path, is formed between the outer peripheral surface of the filter 106 and the inner peripheral surface of the casing 103. This makes it possible to utilize the entire surface of the filter 106.

[0023] In the gas generator 100 configured in this manner, upon actuation of the igniter assembly 1, the transfer charge 111 disposed near it is ignited and burned. Flame generated by the ignition and combustion is expelled into the combustion chamber 110 through the flame transfer holes 107 formed in the inner tube member 108. With this flame, the gas generating agent 105 in the combustion chamber 110 is ignited and burned, thus generating combustion gas. The combustion gas is purified and cooled as it passes through the filter 106, breaks through the sealing band 114 that closes the gas discharge port 104, and then exits to the outside through the gas discharge port 104.

[0024] The igniter assembly 1 is described below with reference to Fig. 2 described. Fig. 2 is an axial cross-sectional view of the igniter assembly 1 according to the present embodiment. The igniter assembly 1 includes the igniter 2. The igniter 2 includes an ignition section 3 containing an ignition agent, a holding section 4 holding the ignition section 3, and an electrically conductive pin 5 configured to activate the ignition section 3. The igniter 2 is of an electric ignition type configured to combust an ignition agent within the ignition section 3 using ignition current supplied from the electrically conductive pin 5.

[0025] The ignition section 3 has a cup-shaped body. The ignition section 3 includes a tube peripheral wall section 31, a lid section 32 that closes one end of the tube peripheral wall section 31, and a receiving space 33 formed with the tube peripheral wall section 31 and the lid section 32 and receiving an ignition agent therein. The lid section 32 is arranged so that the lid section is located on a side to which a combustion product of the ignition agent escapes when the igniter 2 is actuated. For example, the igniter assembly 1 is arranged within the housing 103 such that the lid section 32 faces a filling position of the transfer charge 111, as shown in Fig. 1. With this arrangement, in a case where the igniter 2 of the igniter assembly 1 is actuated, the combustion product can be ejected from the ignition means toward the transfer charge 111 to ignite and burn the transfer charge 111. Here, the direction of the central axis of the igniter assembly 1 is referred to as the vertical direction of the igniter assembly. The lid portion 32 side is referred to as the top side (above the paper surface of Fig. 2) of the igniter assembly 1. The opposite side of this side is called the bottom side (below the paper surface of Fig. 2) of the igniter assembly 1. In Fig. 2, the central axis of the igniter assembly 1 is shown by a two-dot chain line. It should be noted that the central axis of the igniter assembly 1 coincides with the central axes of the ignition section 3 and the igniter collar 6 (fixing section 60), which will be described later.

[0026] The holding portion 4 is made of resin and surrounds a part of the ignition portion 3 to hold the ignition portion 3. During the manufacturing process for the igniter 2, the holding portion 4 is formed by injection molding using a resin material. As the resin material for forming the holding portion 4, a resin material that exhibits excellent heat resistance, durability, corrosion resistance, and the like after curing can preferably be used. Examples of such a resin material include thermoplastic resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin, polypropylene sulfide resin, and polypropylene oxide resin; and thermosetting resins such as epoxy resin. Note that the holding portion 4 can be formed to surround the entire periphery of the ignition portion 3.

[0027] A pair of electrically conductive pins 5 are electrically insulated from each other, and a bridge wire (not shown) is bridge-connected between the pins within the receiving space 33 of the ignition section 3. The ignition agent housed in the receiving space 33 of the ignition section 3 is in contact with the bridge wire (not shown) bridge-connected between the electrically conductive pins 5. The ignition agent is ignited and burned by the heat generated by the bridge wire, producing a combustion product. In this way, the igniter 2 causes the ignition agent to burn, and the resulting combustion product is discharged.

[0028] In addition, the igniter assembly 1 includes the igniter collar 6 to which the igniter 2 is attached. The igniter collar 6 includes a metal fixing portion 60 surrounding the holding portion 4 to fix the holding portion 4, and also includes an attachment portion 61 that engages the open-end portion 112 of the inner tube member 108 at the time of attachment to the Fig. 1. The attachment portion 61 is shaped so that the diameter of this portion is slightly smaller than the diameter of the space 109 of the gas generator 100, to the extent that the attachment portion 61 fits into the space 109, and the attachment portion 61 is fitted into the space 109. A mode in which the igniter 2 is attached to the igniter collar 6 will be described below.

[0029] An opening 62 is formed in an upper-side end portion of the fixing portion 60 in the axial direction. An opening 63 is formed in a lower-side end portion in the axial direction. The fixing portion 60 has a tubular shape with both ends open and includes a tip-end portion 60a, a middle portion 60b, and a bottom surface portion 60c. The bottom surface portion 60c supports the holding portion 4 from below and is located at the lowest portion of the fixing portion 60.

[0030] The center portion 60b extends upward from the bottom surface portion 60c in the axial direction of the igniter assembly 1 and is connected to the tip end portion 60a located on the top end side. At the time of manufacturing the igniter collar 6, the tip end portion 60a extends straight from the center portion 60b. During the process of attaching the igniter 2 to the igniter collar 6, the tip end portion 60a is bent inward to crimp the holding portion 4.

[0031] The holding portion 4 includes a slope portion 41 inclined downward from the igniter assembly 1 and surrounding a part of the circumference of the tube peripheral wall portion 31, an opposing portion 43 opposed to the bottom surface portion 60c of the fixing portion 60, and a peripheral wall portion 42 connecting the slope portion 41 and the opposing portion 43. The tip end portion 60a is bent toward the inside of the igniter collar 6 until the tip end portion 60a is press-fitted to the slope portion 41, thereby press-fitting the holding portion 4 to the tip end portion 60a. Since the slant portion 41 is inclined downward, the bending angle of the tip-end portion 60a to the center portion 60b can form an obtuse angle, which facilitates the pressing with the tip-end portion 60a.It should be noted that the inclined portion 41 is made of plastic and is formed integrally with the holding portion 4, and the inclined portion 41 may be formed such that the inclined portion 41 extends to a circumference of the upper end of the pipe peripheral wall portion 31 or to the cover portion 32.

[0032] The bottom surface portion 60c supports the igniter 2, which is fitted from the opening 62 side. In the present embodiment, the bottom surface portion 60c is inclined downward toward the inner side of the igniter assembly 1, and the opposing portion 43 is also inclined downward toward this inner side. It should be noted that the bottom surface portion 60c or the opposing portion 43 need not be inclined downward, but may, for example, be formed into a flat shape orthogonal to the axial direction of the igniter assembly 1. It is preferable that the shape of the bottom surface portion 60c and the shape of the opposing portion 43 match each other in this way.

[0033] The peripheral wall portion 42 is formed so that the diameter of this portion is slightly smaller than the inner diameter of the central portion 60b, so that the central portion 60b fits into the peripheral wall portion 42. When the igniter 2 is fitted into the igniter collar 6 from the opening 62 side, the peripheral wall portion 42 is inserted into the central portion 60b while being guided by the central portion 60b. It should be noted that the peripheral wall portion 42 and the central portion 60b can be formed into a conical shape in which the diameter gradually decreases on the lower side. This facilitates the insertion of the peripheral wall portion 42 into the central portion 60b and also enables the firm attachment of the holding portion 4 to the igniter collar 6 after the tip end portion 60c has been crimped.In this way, the fixing portion 60 surrounds a part of the inclined portion 41, the peripheral wall portion 42 and the opposing portion 43 to fix the holding portion 4.

[0034] Additionally, the holding portion 4 includes a sub-portion 45 located at the lowermost portion. A pair of electrically conductive pins 5 are exposed at the lower end portion of the sub-portion 45 and extend downward. Furthermore, the sub-portion 45 has a diameter slightly smaller than the opening 63 of the igniter collar 6 and is fitted into the opening 63.

[0035] In addition, the holding portion 4 includes protrusion portions 44a and 44b formed continuously around a periphery of the holding portion 4 and integrally formed with the holding portion 4. In the present embodiment, the protrusion portion 44a, which corresponds to, for example, a "first protrusion portion," and the protrusion portion 44b (corresponding to, for example, a "second protrusion portion") are formed in the opposing portion 43 concentrically with respect to the central axis of the ignition portion 3. The protrusion portions 44a and 44b protrude from the front surface, which in the present embodiment is the front surface of the opposing portion 43, of the holding portion 4 and are press-fitted to the fixing portion 60, particularly the bottom surface portion 60c in the present embodiment, in a state where the holding portion 4 is fixed to the fixing portion 60.It should be noted that the protrusion portion may be formed on only one of the inclined portions 41, the peripheral wall portion 42, and the opposing portion 43. A plurality of protrusions may be formed on one portion. A plurality of protrusion portions may be formed separately on the inclined portion 41, the peripheral wall portion 42, and the opposing portion 43, or the protrusion portion may be formed on only one of the inclined portions 41, the peripheral wall portion 42, and the opposing portion 43.

[0036] The detonator 2 is attached to the detonator collar 6 in the following manner. This describes the operation and effect achieved by attaching the protrusion portions 44a and 44b. In the detonator assembly 1, it is important to ensure the tightness between the detonator 2 and the detonator collar 6. Generally, if there is a gap between the detonator and the detonator collar, moisture will penetrate through the gap into the interior of a device in which the detonator assembly is arranged. This moisture may affect an explosive or the like in the device. If the moisture affects the explosive, the device may malfunction.For this reason, in the igniter assembly 1 according to the present embodiment, the protrusion portions 44a and 44b are press-fitted to the fixing portion 60 to improve the sealing properties between the igniter 2 and the igniter collar 6, thereby preventing the intrusion of moisture from the outside. It should be noted that, in a state where the holding portion 4 is fixed to the fixing portion 60, the protrusion portions 44a and 44b are pressed against the bottom surface portion 60c to be deformed and are in close contact with the bottom surface portion. This enables further improvement of the sealing properties between the igniter 2 and the igniter collar 6.

[0037] Furthermore, since the protrusion portions 44a and 44b are made of resin and molded integrally with the holding portion 4, the sealing property of the igniter assembly 1 can be improved without using a gasket or other sealing members. In addition, when the holding portion 4 is temporarily detached from the fixing portion 60 because the process of attaching the holding portion 4 of the igniter 2 to the fixing portion 60 of the igniter collar 6 needs to be performed again, the protrusion portions 44a and 44b can be press-fitted again at the time of reattaching the holding portion 4 to the fixing portion 60. In this way, the sealing property of the igniter assembly 1 can be ensured even if this process is repeated.In this way, the sealing property of the igniter assembly 1 according to the present embodiment can be improved without increasing the number of parts, while the assembly can be easily performed.

[0038] From the viewpoint of maintaining airtightness, it is preferable that the protrusion portions 44a and 44b be protrusions that continue in the circumferential direction. It should be noted that even in a case where the protrusion portions 44a and 44b are formed as a plurality of protrusions that are discontinuous in the circumferential direction, a gap can be formed that allows protrusions adjacent in the circumferential direction to be substantially connected to each other due to deformation when the protrusion portions are press-fitted to the fixing portion 60.

[0039] The following is based on the Fig. 3 to 5, a method of assembling an igniter assembly (hereinafter referred to simply as “assembly method”) according to the present embodiment will be described. Fig. 3 is a flowchart of the assembly method according to the present embodiment. In the assembly method according to the present embodiment, the igniter 2 is first assembled as shown in Fig. 3 prepared (step S101). Fig. 4 is an axial cross-sectional view of the igniter 2. Before the protrusion portions 44a and 44b of the igniter 2 according to the present embodiment are press-fitted to the fixing portion 60 to be deformed, the cross-sectional shape of the protrusion portions 44a, 44b is an isosceles triangle in a protrusion direction from the front surface of the opposing portion 43 of the holding portion 4. It should be noted that the cross-sectional shape of the protrusion portions 44a, 44b is not limited to this shape and may also have other polygonal shapes or a semicircular shape.

[0040] Next, the igniter collar 6 is installed as shown in Fig. 3 (step S102). Fig. 5 is an axial cross-sectional view of the igniter collar 6. Before the igniter 2 is attached, the tip end portion 60a of the fixing portion 60 is not bent toward the inner side and extends straight upward from the center portion 60b. Note that either the process of preparing the igniter 2 (step S101) or the process of preparing the igniter collar 6 (step S102) may be performed first, or these processes may be performed simultaneously.

[0041] Next, the igniter 2 is fitted into the igniter collar 6 as shown in Fig. 3 (step S103). Specifically, the igniter 2 is inserted into the opening 62 of the igniter collar 6 from the sub-portion 45 side so that the igniter 2 fits into the igniter collar 6 until the protrusion portions 44a and 44b formed on the opposing portion 43 are brought into contact with the bottom surface portion 60c. Next, the igniter 2 is fixed to the igniter collar 6 (step S104). Specifically, in a state where the protrusion portions 44a and 44b are press-fitted to the bottom surface portion 60c of the fixing portion 60, the tip end portion 60a is pressed against the slope portion 41 to fix the holding portion 4 to the fixing portion 60. This allows the igniter 2 to be attached to the igniter collar 6.It should be noted that in the process of fixing the holding portion 4 to the fixing portion 60 (step S104), the protrusion portion 44a is pressed and deformed against the bottom surface portion 60c of the fixing portion 60 to be brought into contact therewith. This enables the igniter assembly 1 according to the present embodiment to further improve the sealing properties between the igniter 2 and the igniter collar 6. It should be noted that the tip end portion 60a may be crimped, with the protrusion portions 44a and 44b being press-fitted and deformed to the bottom surface portion 60c. That is, in step S104, the deformation and press-fitting of the protrusion portions 44a and 44b and the crimping of the tip end portion 60a can be performed simultaneously. First modified example

[0042] Next, a modified example 1 according to the present embodiment will be described with reference to Fig. 6. An igniter assembly 1 according to the present modified example is characterized by the heights of the protrusion portions 44a and 44b. Fig. 6 is an enlarged view showing only the holding portion 4 at and around the opposing portion 43 of the holding portion 4 from the axial cross section of the igniter 2 according to the present modified example. In the present modified example, the protrusion portion 44a and the protrusion portion 44b are formed concentrically with respect to the central axis of the ignition portion 3 and have different heights projecting from the opposing portion 43 of the holding portion 4. For example, the protrusion portion 44b corresponding to a "second protrusion portion" is formed at a greater height than the protrusion portion 44a (corresponding to a "first protrusion portion") from the opposing portion 43, as shown in Fig. 6 shown.

[0043] By forming the protrusion portions 44a and 44b in this manner, at the time of first fixing the holding portion 4 to the fixing portion 60, the lower protrusion portion 44a is not brought into contact with the bottom surface portion 60c, or only its tip end is brought into contact with the bottom surface portion 60c, while the higher protrusion portion 44b is press-fitted to the bottom surface portion 60c and deformed in a squashed manner, even in a case where a process of fixing the holding portion 4 of the igniter 2 to the fixing portion 60 of the igniter collar 6 needs to be repeated. In this way, the lower protrusion portion 44a can be prevented from being completely deformed in a squashed manner.Thus, when the holding portion 4 is reattached to the fixing portion, the not yet deformed protrusion 44a can be reliably press-connected to the lower surface portion 60c and deformed. With this configuration, the tightness of the igniter assembly 1 according to the present modified embodiment can be ensured even when the holding portion 4 is reattached to the fixing portion 60. In this way, the igniter assembly 1 according to the present modified example can be reassembled, and the sealing properties can be improved. Second modified example

[0044] Next, a modified example 2 according to the present embodiment will be described with reference to FIG. Fig. 7 to 9. An igniter assembly 1 according to the present modified example is characterized by the cross-sectional shape of the protrusion portions 44a and 44b. Fig. 7 to 9 are enlarged views in which only the holding portion 4 at and around the opposing portion 43 of the holding portion 4 is extracted from the axial cross section of the igniter 2 according to the present modified example. In the Fig. 7, the cross-sectional shape of the projection portions 44a, 44b is rectangular in a projection direction from the front surface of the opposing portion 43 of the holding portion 4. In the example shown in Fig. 8, the cross-sectional shape of the projection portions 44a, 44b is a trapezoidal shape (for example, an isosceles trapezoidal shape) in a projection direction from the front surface of the opposing portion 43 of the holding portion 4. In the example shown in Fig. 9, the cross-sectional shape of the protrusion portions 44a, 44b is a semicircular shape in a protrusion direction from the front surface of the opposing portion 43 of the holding portion 4. Thus, the cross-sectional shape of the protrusion portions 44a, 44b may be a rectangular shape, a trapezoidal shape, or a semicircular shape, or a combination of these shapes. The protrusion portions 44a and 44b according to the present modified example shown in Fig. 7 to 9 each have a width in the cross-sectional shape that is larger than a height of the projection from the front surface of the opposing portion 43. Here, the width in the cross-sectional shape is a width in a direction orthogonal to a projection direction from the front surface of the opposing portion 43. In this way, the cross-sectional shape of the projection portions 44a, 44b is rectangular, trapezoidal, or semicircular, and the width of the cross-sectional shape is larger than the height of the projection from the front surface of the holding portion 4. In this way, the projection portions 44a, 44b can be prevented from being deformed when these portions are brought into contact with a jig or other parts during the assembling process.This makes it possible to prevent deformation of the protrusion portions 44a and 44b in a state before insertion and to cause the protrusion portions 44a and 44b to be press-fitted to the fixing portion 60 at the time of fixing the holding portion 4 to the fixing portion 60 or after the fixing as intended. With the igniter assembly 1 according to the present modified example, the sealing property can be improved while facilitating the assembly process. Third modified example

[0045] Next, a modified example 3 according to the present embodiment will be described with reference to FIG. Fig. 10 and Fig. 11. An igniter assembly 1 according to the present modified example is characterized in that the fixing portion 60 has groove portions 64a and 64b. Fig. 10 and Fig. 11 are enlarged views in which the opposing portion 43 of the holding portion 4 and its vicinity are extracted from the axial cross section of the igniter 2 according to the present modified example.

[0046] As in Fig. As shown in FIG. 10, the fixing portion 60 in the present modified example includes the groove portions 64a and 64b formed at positions corresponding to the protrusion portions 44a and 44b. The cross-sectional shape of the groove portions 64a, 64b in the axial direction of the fixing portion 60 is, for example, rectangular. In a case where the protrusion portions 44a, 44b are press-fitted to the fixing portion 60, the protrusion portions 44a, 44b are fitted into the groove portions 64a, 64b and deformed into a shape corresponding to a shape of the groove portions 64a, 64b. Fig. 11 is a cross-sectional view showing a state in which the holding portion 4 is fitted into the fixing portion 60 and before the protrusion portions 44a, 44b are brought into contact with the bottom surface portion 60c. The groove portions 64a, 64b are formed to have a depth (d) shorter than the height (h) of the protrusion portion 44a projecting from the front surface, in this modified example, the front surface of the opposing portion 43, of the holding portion 4. In this modified example, a relationship of d < h / 2 is satisfied. That is, the depth of the groove portions 64a, 64b is shorter than half the height of the protrusion portions 44a, 44b. In the process of fixing the holding portion 4 to the fixing portion 60, the projection portions 44a, 44b are pressed against the bottom of the groove portions 64a, 64b, as shown in Fig. 10. As a result, the projection portions 44a, 44b are fitted into the groove portions 64a, 64b and thus deformed into a shape corresponding to the shape of the groove portions 64a, 64b. This enables a further improvement in the sealing properties between the igniter 2 and the igniter collar 6. It should be noted that the ratio between the depth (d) of the groove portions 64a, 64b and the projection portions 44a, 44b is a ratio as shown in Fig. 11. That is, the groove portions 64a, 64b can be filled with the deformed protrusion portions 44a, 44b. Thus, the ratio between the height (h) and the depth (d) can be appropriately changed depending on the cross-sectional shape of the groove portions 64a, 64b, the cross-sectional shape of the protrusion portions 44a, 44b, and the relative dimensions of these portions. Second embodiment

[0047] In the following, an igniter assembly 1 according to a second embodiment is described with reference to the Fig. 12 and Fig. 13 described. Fig. Fig. 12 is an axial cross-sectional view of the igniter assembly 1 according to the present embodiment. It should be noted that in the Fig. 12 and Fig. 13, the same reference numerals are assigned to substantially the same configurations as in the first embodiment described above, so that an explanation is omitted.

[0048] The igniter assembly 1 according to the present embodiment includes a protrusion portion 44, and is characterized in that the protrusion portion 44 is formed on the peripheral wall portion 42 of the holding portion 4. The protrusion portion 44 may be formed on any one of the inclined portions 41, the peripheral wall portion 42, or the opposing portion 43, as long as the protrusion portion 44 can be press-connected to the fixing portion 60. Furthermore, the protrusion portion may be formed, for example, on any of the inclined portions 41, the peripheral wall portion 42, and the opposing portion 43. In the present embodiment, the projection portion 44 is also press-fitted to the center portion of the fixing portion 60 in the direction of the central axis in a state where the holding portion 4 is fixed to the fixing portion 60.This makes it possible to improve the sealing properties between the igniter 2 and the igniter collar 6 in the igniter assembly 1 according to the present embodiment.

[0049] In a case where the projection portion 44 is formed on the peripheral wall portion 42 as in the present embodiment, an igniter collar 6 is manufactured having a shape in which the diameter of the fixing portion 60 increases toward the tip end portion 60a as shown in Fig. 13 shown. Fig.13 is a cross-sectional view showing the state after fitting the igniter 2 into the fixing portion 60 and before fixing the holding portion 4 to the fixing portion 60. Before the tip end portion 60a is bent toward the inner side, the fixing portion 60 expands toward the tip end portion 60a. In a case where the tip end portion 60a is pressed against the slant portion 41 in this way, a so-called roll crimping method can be applied. The roll crimping method is a processing method in which a rod-shaped jig having a roller at the tip end and a roller is pressed against the entire circumference of the outer circumference of the tip end portion 60a to bend and crimp the tip end portion 60a toward the inner side.By bending the tip end portion 60a toward the inside using the roll crimping method, the holding portion 4 is fixed to the fixing portion 60 in a state where the protrusion portion 44 is press-fitted to the center portion 60b of the fixing portion 60. At the time of performing this fixing process (step S104), the protrusion portion 44 is pressed and deformed against the center portion 60b to be brought into close contact therewith in an airtight manner. This makes it possible to improve the sealing properties between the igniter 2 and the igniter collar 6 in the igniter assembly 1 according to the present embodiment. Other examples

[0050] The embodiments according to the present disclosure have been described. However, various embodiments described above may be combined as desired. For example, the peripheral wall portion 42 may have a plurality of protrusions. In this case, the heights of these protrusions may be different from each other, or a groove may be formed at a location corresponding to a protrusion of the central portion 60b.

[0051] Any embodiment described in the present specification may be combined with any of the features described in the present specification. Reference symbol list 1 igniter assembly 2 detonators 3 Ignition section 4 Holding section 5 electrical conductive pin 6 detonator collars 31 Pipe-peripheral-wall section 32 Lid section 33 Recording Room 41 Inclined section 42 Peripheral wall section 43 Opposite section 44, 44a, 44b projection section 45 Sub-Section 60 Fixing section 60a tip-to-end section 60b Middle section 60c Floor-surface section 61 Attachment section 62, 63 Opening 64a, 64b groove section 100 gas generator 101 Upper shell 102 Lower shell 103 housings 104 Gas discharge connection 105 Gas generating means 106 filters 107 Flame transmission hole 108 inner tube element 109 Room 110 Combustion Chamber 111 Transfer Charge 112 Open-end section 113 gap 114 Sealing tape 115 sub-plate

Claims

An igniter assembly (1) comprising:an electric ignition type igniter (2) includingan ignition portion (3) including an ignition means,a holding portion (4) made of resin that covers at least a portion of the periphery of the ignition portion (3) and holds the ignition portion (3), andan electroconductive pin (5) configured to energize the ignition portion (3);and an igniter collar (6) made of metal and to which the igniter (2) is attached, wherein the igniter collar (6) includes a fixing portion (60) surrounding the holding portion (4) to fix the holding portion (4), the holding portion (4) includes a projection portion (44, 44a, 44b) formed continuously around a periphery thereof and formed integrally with the holding portion (4), and the projection portion (44, 44a, 44b) is press-connected to the fixing portion (60), in a state in which the holding portion (4) is fixed to the fixing portion (60), characterized in that in a state in which the holding portion (4) is fixed to the fixing portion (60), the projection portion (44, 44a, 44b) is pressed and deformed against the fixing portion (60), wherein a tip end of the projection portion (44, 44a, 44b) is squeezed and deformed to be in airtight close contact with the fixing portion (60);The igniter assembly (1) according to claim 1, characterized in that the ignition section (3) includes a tube peripheral wall section (31), a lid section (32) that closes one end of the tube peripheral wall section (31), and a receiving space (33) formed with the tube peripheral wall section (31) and the lid section (32) and in which the ignition agent is received. The lid section (32) is arranged so that the lid section (32) is located on a side toward which a combustion product of the ignition agent is discharged when the igniter (2) is actuated. The holding section (4) includes a slant section (41) that is inclined downward from the igniter assembly (1) and surrounds at least a portion of a circumference of the tube peripheral wall section (31). and is crimped to a tip-end portion (60a) of the fixing portion (60), a counter portion (43),which faces a bottom surface portion of the fixing portion (60), and a peripheral wall portion (42) connecting the inclined portion (41) and the opposing portion (43). The projection portion (44, 44a, 44b) is formed on at least one of the inclined portion (41), the peripheral wall portion (42), or the opposing portion (43), and the fixing portion (60) surrounds at least a portion of the inclined portion (41), the peripheral wall portion (42), and the opposing portion (43) to fix the holding portion (4). The igniter assembly (1) according to claim 1 or 2, characterized in that a plurality of the protrusion portions (44a, 44b) are formed on the holding portion (4), the plurality of protrusion portions include a first protrusion portion (44a) and a second protrusion portion (44b), and the first protrusion portion (44a) and the second protrusion portion (44b) are formed concentrically with respect to a central axis of the igniter portion (3) and have different heights protruding from the holding portion (4). The igniter assembly (1) according to claim 3, characterized in that the second protrusion portion (44b) is formed on an outer side from the central axis than the first protrusion portion (44a), and the second protrusion portion (44b) has a greater height protruding from the holding portion (4) than the first protrusion portion (44a). The igniter assembly (1) according to any one of claims 1 to 4, characterized in that a cross-sectional shape of the protrusion portion (44, 44a, 44b) in a protrusion direction from a surface of the holding portion (4) is a rectangular shape, a trapezoidal shape or a semicircular shape, and a width of the cross-sectional shape is larger than a height of the protrusion from the front surface. The igniter assembly (1) according to any one of claims 1 to 5, characterized in that the fixing portion (60) includes a groove portion (64a, 64b) formed at a position corresponding to the projection portion (44, a 44b), and in a case where the projection portion (44, a 44b) is press-fitted to the fixing portion (60), the projection portion (44, a 44b) is fitted into the groove portion (64a, 64b) and deformed into a shape corresponding to a shape of the groove portion (64a, 64b). The igniter assembly (1) according to any one of claims 1 to 6, characterized in that the projection is formed as a plurality of projections which are interrupted in the circumferential direction of the holding portion (4), one projection is substantially connected to an adjacent projection in the circumferential direction, in a state in which the plurality of projections are press-connected to the fixing portion (60). A method of assembling an igniter assembly (1) in which an igniter (2) of an electric ignition type is attached to an igniter collar (6) made of metal, the method comprising: manufacturing the igniter (2) including an ignition portion (3) including an ignition means, a holding portion (4) made of resin that covers at least a portion of the periphery of the ignition portion (3) and holds the ignition portion (3), and an electroconductive pin (5) configured to energize the ignition portion (3);and manufacturing the igniter collar (6) including a fixing portion (60) surrounding the holding portion (4) to fix the holding portion (4), wherein the holding portion (4) includes a projection portion (44, 44a, 44b) formed continuously around a periphery thereof and formed integrally with the holding portion (4), and the method for assembling an igniter assembly (1) further includes fixing the holding portion (4) to the fixing portion (60) in a state in which the projection portion (44, 44a, 44b) is press-connected to the fixing portion (60), characterized in that when fixing the holding portion (4) to the fixing portion (60), the projection portion (44, 44a, 44b) against the fixing portion (60) is pressed and deformed, wherein a tip end of the projection portion (44, 44a, 44b) is squeezed and deformed to be in airtight close contact with the fixing portion (60);

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