Ignition device

Abstract

To provide an ignition device allowing not only necessary function in accordance with an object or an application to be secured but its assembly to be easily carried out.SOLUTION: An ignition device 100 is provided with: an igniter 10 receiving igniter powder 11 ignited through electrification; and a holder 20 having an insertion opening 21a for insertion of an igniter 10 and integrated to the igniter 10 through fitting the igniter 10 from the insertion opening 21a and pressing-in a tube body 12 to a press-fit part 21c. An end part 12a of the tube body 12 is fitted in a circular groove 21d formed in a hole part 21, so a labyrinth structure is formed with an inner wall part of the end part 12a, an end surface part, an outer wall part, and the circular groove 21d.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an ignition device used in a safety device for an automobile or the like. [Background technology]

[0002] Conventionally, seat belt devices and airbag devices have become widespread from the viewpoint of protecting occupants of automobiles, etc. Of these, seat belt devices are installed for the purpose of preventing occupants from being thrown into or outside the vehicle due to the impact that occurs in the event of a vehicle collision, etc., and restrain and fix the occupant in the seat by wrapping a belt around the occupant's body.

[0003] In recent years, seat belt devices equipped with a pretensioner function have become widespread in order to improve occupant protection. This pretensioner function instantly tightens the seat belt at the time of or immediately before a collision to compensate for slack in the seat belt caused by factors such as the thickness of clothing, thereby enhancing the occupant's restraint effect. This pretensioner function is realized by tightly retracting the seat belt using the gas pressure output from a gas generator known as a micro gas generator (MGG).

[0004] An example of an ignition device used in such a gas generator is disclosed in Patent Document 1. The ignition device for the gas generator in Patent Document 1 includes an igniter that is disposed inside the cup body and ignites the gas generating agent when current is applied, and a holder that seals the gas generating agent within the cup body, and the holder is made of resin and is integrated with the igniter by insert molding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-239371 Summary of the Invention [Problem to be solved by the invention]

[0006] Although the ignition device in Patent Document 1 performs satisfactorily when used in a seatbelt device with a pretensioner function, such function may be excessive in light of the purpose or application. For example, if the ignition device in Patent Document 1 is simply used as an ignition device for a current breaker, its original capacity may be excessive, and part of the manufacturing cost may be wasted.

[0007] Therefore, an object of the present invention is to provide an ignition device that can ensure the necessary functions according to the purpose or use, and that can be easily assembled by reducing the number of parts compared to conventional devices. [Means for solving the problem]

[0008] (1) An ignition device according to the present invention is an ignition device comprising: an igniter that stores an ignition charge that is ignited by energization; and a holder into which the igniter is fitted to be integrated with the igniter, wherein the igniter comprises a tubular body having an opening and containing the ignition charge therein; a plug that closes the opening and seals the ignition charge inside the tubular body; and a pair of terminal pins provided on the plug, wherein an end of the tubular body that forms the opening is formed to protrude relative to the plug, and the holder is internally formed and has an insertion opening through which the igniter is inserted and a press-fitting portion into which the tubular body is press-fitted through the insertion opening, and comprises a hole into which the igniter is fitted and fixed by press-fitting the tubular body into the press-fitting portion through the insertion opening, and an annular groove that is formed in a part of the inner wall of the hole and into which the end of the tubular body is fitted, and wherein the end of the tubular body fitted into the annular groove and the annular groove are to Therefore, a labyrinth structure is formed. a surface of the plug opposite to the side where the ignition charge is disposed (hereinafter referred to as the opposite surface) is in contact with a surface formed on the inner wall of the hole portion radially inward from the annular groove so as to face the opposite surface, and a tapered shape is formed in the middle from the surface formed on the inner wall of the hole portion radially inward from the annular groove so as to face the opposite surface to a portion of the hole portion on the side opposite to the side where the tube is press-fitted, into which the pair of terminal pins are inserted, the tapered shape having a diameter decreasing in the press-fitting direction. It is characterized by the presence of

[0011] ( 2 ) The present invention provides an ignition device comprising: an igniter that stores an ignition charge that is ignited by passing current through it; and a holder that is integrated with the igniter by being fitted into the holder, wherein the igniter comprises: a tubular body that contains the ignition charge inside and has an opening; a plug that closes the opening and seals the ignition charge inside the tubular body; and a pair of terminal pins provided on the plug, wherein an end of the tubular body that forms the opening is formed to protrude relative to the plug, and the holder is formed internally with an insertion opening through which the igniter is inserted and a press-fitting portion into which the tubular body is press-fitted through the insertion opening, and comprises: a hole into which the igniter is fitted and fixed by press-fitting the tubular body into the press-fitting portion through the insertion opening; and an annular groove that is formed in a part of the inner wall of the hole and into which the end of the tubular body is fitted, wherein a labyrinth structure is formed by at least the end of the tubular body fitted into the annular groove and the annular groove, An annular weakened portion is formed on the outer periphery of the insertion opening. It may also be .

[0012] ( 3 ) above (1) or ( 2 In the ignition device of the above, it is preferable that a tapered shape is formed between the insertion opening of the hole portion and the press-fit portion, the diameter of which decreases along the press-fit direction.

[0013] ( 4 ) above (1)~( 3 In the ignition device of the above, it is preferable that a pair of through holes into which each of the pair of terminal pins is inserted is formed in a portion of the hole portion on the side opposite to the side into which the tube body is press-fitted, into which the pair of terminal pins are inserted.

[0014] According to the above configurations (1) to (6), it is possible to provide an ignition device that can ensure the necessary functions according to the purpose or use, and that can be easily assembled by reducing the number of parts compared to conventional devices. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a side view showing an ignition device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the ignition device of FIG. [Figure 3] FIG. 3 is a partially enlarged view of the ignition device of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0016] An ignition device according to an embodiment of the present invention will now be described with reference to the drawings. The ignition device can be used, for example, as a current breaker that burns off a conducting wire or cuts off the conducting wire by moving a piston.

[0017] As shown in Figures 1 to 3, the ignition device 100 of this embodiment includes an igniter 10 that stores an ignition charge 11 that is ignited when electricity is applied, and a holder 20 that has an insertion opening 21a for inserting the igniter 10 and is integrated with the igniter 10 by fitting the igniter 10 through the insertion opening 21a.

[0018] The igniter 10 includes a tubular body 12 in which an ignition charge 11 is loaded, a metal plug 13 that seals the ignition charge 11 inside the cylindrical tubular body 12 with an opening and a bottom, a pair of terminal pins 14 protruding from the plug 13, an insulator 15 such as glass that provides insulation between the terminal pins 14, and a bridge wire 16 that is connected between the terminal pins 14 on the insulator 15 inside the tubular body 12 and comes into contact with the ignition charge 11. An end 12a of the tubular body 12 is formed to protrude from the plug 13. The plug 13 has a surface 13a formed on the side opposite to the ignition charge 11 side.

[0019] In the igniter 10, when a current is applied to the bridge wire 16 via a pair of terminal pins 14, the bridge wire 16 generates Joule heat, which instantly ignites the ignition charge 11, causing a rise in pressure within the tubular body 12 and plug 13, which then ruptures the bottom of the tubular body 12. At this time, the flame and pressure wave of the ejected ignition charge 11 can burn off, for example, a conducting wire or act as a driving source for driving a moving body such as a piston.

[0020] Furthermore, igniter 10 is fixed to holder 20 with a pair of terminal pins 14 inserted through hole 21 formed approximately in the center of holder 20, and with the central axis of igniter 10 itself approximately aligned with the central axis of holder 20. Specifically, igniter 10 is fixed to holder 20 by press-fitting cylindrical portion 12b of tube body 12 into press-fit portion 21c formed in hole 21 of holder 20. Furthermore, end portion 12a of tube body 12 is fitted into annular groove 21d (described below) formed in hole 21, and a labyrinth structure is formed by at least the inner wall portion, end face portion, and outer wall portion of end portion 12a and annular groove 21d. In addition, this labyrinth structure may also include a portion formed by the outer wall of the tube body 12, the inner wall of the press-fit portion 21c, the surface 13a, the seating surface 21e described below, the second tapered portion 21f described below, and the pair of through holes 21g described below.

[0021] Holder 20 is a generally cylindrical member having hole 21 formed in the center, into which igniter 10 is inserted and press-fitted. Hole 21 is composed of insertion opening 21a, first tapered portion 21b, press-fit portion 21c, annular groove 21d, seating surface 21e, second tapered portion 21f, through-hole 21g, and female connector portion 21h. Holder 20 is formed as a single unit by, for example, injection molding using a fluid resin material.

[0022] Insertion opening 21a has an inner diameter larger than the outer diameter of tube body 12, and serves as a guide portion when inserting igniter 10. Furthermore, an annular weakened portion 22 is formed on the outer periphery of holder 20 facing insertion opening 21a, and a notch 23 is formed at the upper end of insertion opening 21a. When a protruding portion of holder 20, including first tapered portion 21b and press-fit portion 21c, receives combustion pressure generated by activation of igniter 10 in the outward direction via tube body 12, weakened portion 22 becomes the starting point of damage, thereby protecting press-fit portion 21c and preventing tube body 12 from being released from being press-fitted into press-fit portion 21c.

[0023] First tapered portion 21b is formed between insertion opening 21a and press-fit portion 21c, and has a tapered shape that reduces in diameter along the press-fit direction of tube body 12, and serves to guide tube body 12 into press-fit portion 21c. In other words, compared to a case in which first tapered portion 21b is not formed, the ease of insertion (assembly) of igniter 10 is improved.

[0024] The press-fit portion 21c is a portion into which the tube body 12 is press-fitted and fixed, thereby holding the igniter 10 and improving the airtightness (sealing property) inside the igniter 10.

[0025] The annular groove 21d is connected to the press-fit portion 21c and is a portion that fits over the end portion 12a of the tubular body 12. The annular groove 21d, together with the inner wall, end face, and outer wall of the end portion 12a, forms a labyrinth structure. This labyrinth structure, together with the press-fit portion 21c, not only maintains the combustion pressure generated by the igniter 10 (preventing leakage of gas generated when the igniter 10 is activated) but also withstands mechanical vibrations and shocks during activation when the igniter 10 is mounted on a vehicle. The depth of the annular groove 21d is deeper than the protrusion of the end portion 12a of the tubular body 12, so that the igniter 10 seats (contacts) on the seating surface 21e via the surface 13a of the plug 13 opposite the side where the ignition charge 11 is disposed. Applying an adhesive or sealant to the annular groove 21d before fitting the end portion 12a improves airtightness (sealing), allowing the use of a higher-pressure igniter 10.

[0026] The seating surface 21e is formed radially inward from the annular groove 21d on the inner wall of the hole portion 21 so as to face the surface 13a, and is the surface on which the surface 13a of the plug 13 of the igniter 10 seats (contacts).

[0027] Second tapered portion 21f is formed between seating surface 21e and pair of through holes 21g, and has a tapered shape that reduces in diameter along the press-fit direction of tube body 12. Second tapered portion 21f has a guide function similar to that of first tapered portion 21b, and improves the insertability (assembly) of igniter 10 (particularly the pair of terminal pins 14) compared to a case where second tapered portion 21f is not formed.

[0028] The pair of through holes 21g regulate the clearance (gap) between the pair of terminal pins 14 and the holder 20, thereby improving airtightness and enabling the circumferential positioning and movement restriction of the igniter 10.

[0029] The female connector portion 21h is a portion formed to hold the pair of terminal pins 14 in a partially exposed state and to connect a male connector (not shown) of a harness for electrically connecting the pair of terminal pins 14 to, for example, a control unit (not shown).

[0030] Notch 23 is formed as a single part so as to serve as the starting point of the damaged portion if fragile portion 22 is damaged during operation, and can stabilize the shape of the damaged state (scattered debris). Note that, if necessary, fragile portion 22 and notch 23 can be changed in shape or position, or multiple notches can be provided, to reduce scattered debris.

[0031] In the ignition device 100 configured as described above, a flame generated by the activation of the igniter 10 can break or melt an object (such as a conductor). In addition, a pressure wave generated by the activation of the igniter 10 can be used as a driving force for moving a moving body such as a piston. In this case, the ignition device 100 can be used as a driving source for a current breaker configured so that a cutter is attached to the tip of the piston and the conductor can be cut after the piston moves.

[0032] As described above, according to this embodiment, it is possible to provide the ignition device 100 that can ensure the necessary functions according to the purpose or application.

[0033] Furthermore, according to this embodiment, an ignition device 100 can be provided that can be easily assembled by reducing the number of parts compared to conventional devices, depending on the purpose or application. For example, an insulating cover is not necessary if the igniter 10 and the part to which the ignition device 100 is attached are metal parts and there is no possibility of contact between them. In particular, when the igniter 10 is used as a current breaker, an insulating cover is not necessary if there is a space between the igniter 10 and a piston that moves due to the pressure wave generated by the igniter 10, or if the piston is made of resin. However, when the ignition device is incorporated into a micro gas generator (MGG), an insulating cover is necessary for the igniter tube, which comes into contact with the gunpowder, and the like.

[0034] Furthermore, according to this embodiment, since the holder 20 is made of resin, material costs can be reduced and the weight can be reduced compared to when it is made of metal. Furthermore, since the holder 20 is formed by injection molding as a single unit, the mold structure is simpler than when it is integrally molded with the igniter 10, and insert molding as in the past is not required, making it possible to shorten the molding cycle time and reduce manufacturing costs. Furthermore, since the holder 20 is made of resin, it has a higher degree of freedom in shape compared to when it is made of metal, making it easier to change the shape and attach other parts as needed. Furthermore, since the holder 20 is made of resin, there is no risk of poor insulation due to metal burrs (caused by caulking or cutting residue) as occurs when it is made of metal.

[0035] Furthermore, according to this embodiment, the assembly process involves only assembling igniter 10 to holder 20, which reduces the process load compared to conventional processes. Furthermore, according to this embodiment, the assembly process involves assembly by press-fitting, but does not include a crimping process or the like because the igniter is stopped by abutting against seating surface 21e, so detailed process management is not required, making manufacturing easier and enabling the equipment to be made more compact.

[0036] Furthermore, the depth of annular groove 21d is deeper than the protrusion allowance of end 12a of tube body 12, and igniter 10 is seated on seating surface 21e via surface 13a of plug 13. This absorbs variations in the assembly accuracy of igniter 10 and the dimensions of end 12a, improving the assembled dimensional accuracy of ignition device 100, and standardizing holder 20 (allowing igniter 10 to be replaced with a different type of igniter to create variations in the ignition device) minimizes the impact of differences in product types, resulting in cost reductions. For example, mass production of a single part of holder 20 reduces the unit price of the part, costs are reduced by simplifying the assembly equipment, and assembly costs are reduced by eliminating the need for stage changes.

[0037] The extent to which terminal pin 14 protrudes from holder 20 is regulated by the standards of the connector to be mated with female connector portion 21h. According to this embodiment, by seating igniter 10 on seating surface 21e via surface 13a of plug 13, the standards of the connector can be easily met, and since surface 13a is pressed against seating surface 21e during assembly, precise control of positional accuracy is not required, and relatively high positional accuracy can be provided, albeit in a simple manner.

[0038] Furthermore, the fragile portion 22 can protect the press-fit portion 21c and the above-mentioned labyrinth structure from the combustion pressure generated in the igniter 10.

[0039] Furthermore, if the fragile portion 22 is broken during operation, the cutout portion 23 serves as the starting point for the broken portion, and the shape of the broken state (scattered debris) can be stabilized.

[0040] Although the embodiments of the present invention have been described above with reference to the drawings, it should be understood that the specific configurations are not limited to these embodiments. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0041] 10 Igniter 11 Ignition Powder 12. Body 12a end 12b Cylinder part 13 Embolism 13a side 14 terminal pins 15 Insulators 16 Denbashi Line 20 Holder 21 Hole 21a insertion slot 21b First tapered portion 21c Press-fit part 21d Annular groove 21e Seating surface 21f Second tapered section 21g through hole 21h Female connector 22 Weak part 23 Cutout 100 Ignition system

Claims

1. An ignition device comprising: an igniter that stores an ignition charge that is ignited by energization; and a holder into which the igniter is fitted to be integrated with the igniter, The igniter is a tube having an opening and containing the ignition charge therein; a plug that closes the opening and seals the ignition charge inside the tube; a pair of terminal pins provided on the plug; Equipped with an end of the tubular body forming the opening is formed to protrude toward the plug; The holder is a hole portion formed inside the hole portion, the hole portion having an insertion opening into which the igniter is inserted and a press-fitting portion into which the tube body is press-fitted through the insertion opening, the hole portion into which the igniter is fitted and fixed by press-fitting the tube body into the press-fitting portion through the insertion opening; an annular groove formed in a part of an inner wall of the hole portion, into which the end of the pipe is fitted; Equipped with a labyrinth structure is formed by at least the end of the pipe fitted into the annular groove and the annular groove, a surface of the plug opposite to the side on which the ignition charge is disposed (hereinafter referred to as the "opposite surface") is in contact with a surface formed on the inner wall of the hole portion, radially inward of the annular groove, so as to face the opposite surface; an ignition device characterized in that a tapered shape is formed in the direction of the press-fitting from a surface formed on the inner wall of the hole portion that is radially inward from the annular groove and faces the opposite surface to a portion of the hole portion on the side opposite to the side where the tube body is press-fitted and into which the pair of terminal pins are inserted.

2. An ignition device comprising an igniter that stores an ignition charge that is ignited by passing current through it, and a holder into which the igniter is fitted to be integrated with the igniter, The igniter is a tube having an opening and containing the ignition charge therein; a plug that closes the opening and seals the ignition charge inside the tube; a pair of terminal pins provided on the plug; Equipped with an end of the tubular body forming the opening is formed to protrude toward the plug; The holder is a hole portion formed inside the hole portion, the hole portion having an insertion opening into which the igniter is inserted and a press-fitting portion into which the tube body is press-fitted through the insertion opening, the hole portion into which the igniter is fitted and fixed by press-fitting the tube body into the press-fitting portion through the insertion opening; an annular groove formed in a part of an inner wall of the hole portion, into which the end of the pipe is fitted; Equipped with a labyrinth structure is formed by at least the end of the pipe fitted into the annular groove and the annular groove, An ignition device characterized in that an annular weakened portion is formed on the outer periphery of the insertion opening.

3. 3. The ignition device according to claim 1, wherein a tapered shape is formed between the insertion opening of the hole and the press-fit portion, the diameter of which decreases along the press-fit direction.

4. An ignition device according to any one of claims 1 to 3, characterized in that a pair of through holes into which each of the pair of terminal pins is inserted are formed in a portion of the hole portion opposite to the side into which the tube body is press-fitted, into which the pair of terminal pins are inserted.

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