JP2013159197A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generator, in which manufacturing cost can be reduced and generation of burr in a housing during assembly can be suppressed.SOLUTION: A gas generator 1A comprises an upper shell 10 which is comprised of a bottomed cylindrical metallic member, and a lower shell 20. The lower shell 20 is comprised of molded products by pressing one metallic plate-like member to roughly mold at least a bottom plate part 21 and a lower cylindrical part 22. The lower shell 20 is pressed into the upper shell 10 by inserting an opening end of the lower cylindrical part 22 in the inside of an opening end of an upper cylindrical part 12 of the upper shell 10. An outer circumferential surface of a distal end 22a of the lower cylindrical part 22 in a portion inserted to the upper cylindrical part 12 is inclined inward so as to retreat from an inner circumferential surface of the upper cylindrical part 12, and an outer circumferential surface of a portion other than the distal end 22a of the lower cylindrical part 22 in the portion inserted into the upper cylindrical part 12 is abutted to an inner circumferential surface of the upper cylindrical part 12.

Description

  The present invention relates to a gas generator incorporated in an occupant protection device, and more particularly to a so-called disk-type gas generator incorporated in an airbag device installed in a steering wheel of an automobile.

  2. Description of the Related Art Conventionally, airbag devices, which are occupant protection devices, have been widely used from the viewpoint of protecting occupants such as automobiles. The airbag device is equipped for the purpose of protecting the occupant from the impact generated when the vehicle or the like collides. The airbag is inflated and deployed instantaneously when the vehicle or the like collides, so that the airbag becomes a cushion of the occupant. It is to catch the body.

  The gas generator is incorporated in this airbag device, and ignites the igniter by energization from the control unit at the time of a vehicle collision, etc., and the gas generating agent is burned by the flame generated in the igniter to instantly generate a large amount of gas. This is a device for inflating and deploying the airbag. Note that the airbag device is mounted on, for example, an automobile steering wheel or an instrument panel.

  There are various types of gas generators, and there is a so-called disk-type gas generator as a gas generator suitably used for a driver side airbag device equipped on a steering wheel or the like. In general, a disk-type gas generator has a short cylindrical housing whose end in the axial direction is closed, a gas outlet is provided on the peripheral wall of the housing, and a gas generating agent, an igniter, and a filter are provided inside the housing. Etc. are accommodated.

  The housing of a disk-type gas generator is generally configured by combining a bottomed cylindrical metal member called a lower shell and a bottomed cylindrical metal member called an upper shell. Of these, the lower shell constitutes at least a bottom plate portion of the housing, and an igniter is assembled and fixed to the bottom plate portion.

  Conventionally, since the shape of the upper shell is relatively simple, it has been generally manufactured by pressing a single plate member made of metal. On the other hand, since the shape of the part where the igniter is assembled is complicated, the lower shell is generally manufactured by cutting a metal block. However, the manufacture of the lower shell by such a cutting process has been a factor that greatly reduces the manufacturing cost, and thus improvement has been demanded.

  Therefore, the structure of the lower shell is simplified, and this is manufactured by pressing a single metal plate-like member, and an igniter is inserted into the lower shell manufactured by the press molding by resin molding. Attempts have been made to fix in the department. References disclosing such a configuration include, for example, Japanese Patent Application Laid-Open No. 4-266548 (Patent Document 1), Japanese Translation of PCT International Publication No. 2005-528276 (Patent Reference 2), Japanese Patent Publication No. 2007-521181 (Patent Reference 3). JP, 2010-173558, A (patent documents 4), JP, 2010-173559, A (patent documents 5), JP, 2010-173560, A (patent documents 6), etc. are mentioned.

  In the gas generators disclosed in Patent Documents 1 to 6, an igniter is assembled by insert molding using a resin material as a raw material on a lower shell formed by pressing a single metal plate member. The structure to attach is adopted. More specifically, a resin molded part is formed by pouring an insulating fluid resin material into a space between an igniter arranged in an opening provided in the lower shell and the lower shell and solidifying the same. And the resin molded part is fixed to the surface of the igniter and the surface of the lower shell, respectively, so that the igniter is fixed to the lower shell.

JP-A-4-266548 JP 2005-528276 A Special table 2007-521181 JP 2010-173558 A JP 2010-173559 A JP 2010-173560 A

  Usually, in a disk-type gas generator, the lower shell is press-fitted into the upper shell by inserting or extrapolating the lower shell into the upper shell. The lower shell is fixed by being joined by welding or the like. Here, in order to ensure the airtightness inside the housing, it is necessary that the upper shell and the lower shell are in close contact after press-fitting. Therefore, when manufacturing the upper shell and the lower shell, It is important that the dimensional accuracy is strictly controlled.

  As disclosed in Patent Documents 1 to 6, when the upper side shell and the lower side shell are configured by press-molded products, the dimensional accuracy of the upper side shell and the lower side shell is generally increased by pressing. Since it will be ensured, the press-fitting of the lower shell to the upper shell described above can be performed relatively suitably. However, when press-fitting, the upper shell and the lower shell come into contact with each other, so that the surface thereof is scraped off, and there is a possibility that burrs are generated.

  The burrs generated during the press-fitting described above are not only a cause of joint failure in the subsequent welding or the like due to the adhesion to the outer surface of the housing, but also the burrs are adhered to the terminal pins of the igniter. In this case, it may lead to a serious problem that causes the malfunction of the igniter.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a gas generator capable of reducing the manufacturing cost and suppressing the generation of burrs generated in the housing during assembly. And

  A gas generator according to the present invention includes a top plate portion and a bottom plate portion that close an end portion in the axial direction, and a peripheral wall portion provided with a gas jet port, and includes a combustion chamber containing a gas generating agent therein. And a igniter for burning the gas generating agent. The housing has a first shell and a second shell made of a bottomed cylindrical metal member. The first shell includes a first plate-like portion constituting one of the top plate portion and the bottom plate portion, and a first tubular portion constituting a portion of the peripheral wall portion on the first plate-like portion side. Is included. The second shell includes a second plate-like portion that constitutes the other of the top plate portion and the bottom plate portion, and a second cylindrical portion that constitutes a portion of the peripheral wall portion on the second plate-like portion side. Is included. The igniter is assembled to one of the first plate-like portion and the second plate-like portion. The second shell is formed of a molded product in which at least the second plate-shaped portion and the second cylindrical portion are roughly formed by pressing a single metal plate-shaped member. The opening end of the cylindrical portion is press-fitted into the first shell by being inserted inside the opening end of the first cylindrical portion. The outer peripheral surface of the distal end portion of the second cylindrical portion of the portion inserted into the first cylindrical portion is inclined inward so as to retract from the inner peripheral surface of the first cylindrical portion, The outer peripheral surface of the portion inserted into the first cylindrical portion except the tip portion of the second cylindrical portion is in contact with the inner peripheral surface of the first cylindrical portion.

  In the gas generator according to the present invention, it is preferable that the finish forming of the tip end portion is performed by pressing the tip end portion of the second cylindrical portion that is roughly formed.

  In the gas generator according to the present invention, the second shell is formed such that the finish of the tip is bent or curved inward so that the entirety of the tip of the second cylindrical portion is roughly formed. It is preferable that the bending process is performed by pressing.

  In the gas generator according to the present invention, when the finish of the tip portion is performed by the bending process by the press work described above, the gas jet port provided at the peripheral wall portion is the tip portion. It is preferable to extend to a position covering

  In the gas generator according to the present invention, in the finish molding of the tip portion, the corner portion located on the outer peripheral surface side of the tip portion of the second cylindrical portion that is roughly molded is removed. The second shell may be subjected to a chamfering process by press working.

  In the gas generator according to the present invention, in the finish molding of the tip portion, the corner portion located on the outer peripheral surface side of the tip portion of the second cylindrical portion that is roughly molded is removed. The second shell may be subjected to a chamfering process by cutting.

  In the gas generator according to the present invention, in the case where the finish of the tip portion is performed by the above-described chamfering process by cutting, the tip portion is moved from the inner portion of the tip portion to the peripheral wall portion. It is preferable to have an extending portion that extends to a position that covers the gas ejection port provided in the housing.

  ADVANTAGE OF THE INVENTION According to this invention, it can be set as the gas generator which can reduce production cost and can suppress generation | occurrence | production of the burr | flash produced in a housing at the time of an assembly | attachment.

It is the schematic of the gas generator in Embodiment 1 of this invention. It is the schematic for demonstrating the assembly structure and assembly procedure of the upper side shell with respect to the lower side shell of the gas generator in Embodiment 1 of this invention. It is the schematic of the gas generator in Embodiment 2 of this invention. It is the schematic of the gas generator in Embodiment 3 of this invention. It is a principal part enlarged view of the gas generator in Embodiment 3 of this invention. It is the schematic of the gas generator in Embodiment 4 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment described below, the present invention is applied to a disk-type gas generator incorporated in an airbag device installed in a steering wheel or the like of an automobile. In the following embodiments, the same or common parts are denoted by the same reference numerals in the drawings, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic diagram of a gas generator according to Embodiment 1 of the present invention. First, a schematic structure of the gas generator 1A in the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the gas generator 1A in the present embodiment has a short cylindrical housing closed at both ends in the axial direction, and a holding portion 30 as a component within the housing. The igniter 40, the enhancer cup 50, the transfer agent 54, the gas generating agent 61, the filter 70, and the like are accommodated. The short cylindrical housing has an upper shell 10 as a first shell and a lower shell 20 as a second shell, and a ceiling as a first plate-like portion that closes the end in the axial direction. It is comprised by the baseplate part 21 as the board part 11 and the 2nd plate-shaped part, and the surrounding wall part in which the gas jet nozzle 14 was provided.

  Each of the upper shell 10 and the lower shell 20 is formed in a bottomed cylindrical shape, and a housing is configured by joining these opening surfaces so as to face each other. The upper shell 10 includes a top plate portion 11 constituting the first plate portion, an upper tubular portion 12 as a first tubular portion constituting a portion of the peripheral wall portion on the top plate portion 11 side, and an upper side. The flange part 13 located in the opening end side which is the lower end of the cylindrical part 12 is included. The lower-side shell 20 includes a bottom plate portion 21 that constitutes a second plate-like portion, and a lower-side tubular portion 22 as a second tubular portion that constitutes a portion of the peripheral wall portion on the bottom plate portion 21 side.

  For joining the upper shell 10 and the lower shell 20, welding such as electron beam welding or laser welding is preferably used. Specifically, the open end of the lower cylindrical portion 22 of the lower shell 20 is inserted inside the open end of the upper cylindrical portion 12 of the upper shell 10, so that the lower shell is connected to the upper shell 10. 20 is press-fitted, and in this state, the upper shell 10 and the lower shell 20 are joined by performing a welding process on these boundary portions from the outside. In addition, in the figure, the welding trace produced by the said welding process is typically represented by the site | part shown with the code | symbol W. FIG.

  The upper shell 10 is composed of a press-formed product manufactured by pressing a single metal plate-like member. Specifically, the upper shell 10 is formed into a shape as shown in the figure by pressing a single metal plate-like member from above and below using a pair of molds consisting of an upper mold and a lower mold. Will be produced. Here, as the metal plate-like member, a metal plate made of stainless steel, steel, an aluminum alloy, a stainless alloy, or the like can be used.

  The lower shell 20 is formed by pressing at least a bottom plate portion 21 and a lower cylindrical portion 22 by pressing a single metal plate-like member, and thereafter, finish molding is performed only at necessary portions. It is comprised with the molded article manufactured by this. In rough forming, a single metal plate-like member is pressed from above and below using a pair of molds composed of an upper die and a lower die.

  Here, as the metal plate-like members to be the upper shell 10 and the lower shell 20, for example, stainless steel, steel, aluminum alloy, stainless alloy having a plate thickness before pressing of approximately 1.5 mm to 3.0 mm. A so-called high-tensile steel plate that does not cause breakage or the like even when a tensile stress of 440 MPa or more and 780 MPa or less is applied is preferably used. In addition, as a plate | board thickness after the press of the part which comprises the outer shell of a housing, it is preferable that the thickness of the thinnest part shall be about 1.0 mm or more. The press working may be performed by hot forging or cold forging, but is more preferably performed by cold forging from the viewpoint of improving dimensional accuracy.

  A projecting cylindrical portion 23 that protrudes toward the top plate portion 11 side is provided at a substantially central portion of the bottom plate portion 21 of the lower shell 20, whereby a substantially central portion of the bottom plate portion 21 of the lower shell 20. A recess 24 is formed. The projecting cylindrical portion 23 is a portion to which the igniter 40 is fixed via the holding portion 30, and the hollow portion 24 is a portion serving as a space for providing the female connector portion 36 in the holding portion 30. The projecting cylindrical portion 23 is shaped by the above-described rough molding.

  Here, the projecting cylindrical portion 23 is formed in a bottomed cylindrical shape, and has a tapered shape so that its outer diameter decreases as it approaches the top plate portion 11 side. In addition, an opening 25 having a circular shape in plan view is provided at an end portion in the axial direction located on the top plate portion 11 side of the protruding cylindrical portion 23. The opening 25 is a part through which the pair of terminal pins 42 of the igniter 40 is inserted.

  The detailed shape of the lower shell 20 and the details of finish molding for realizing the shape will be described later.

  A holding portion 30 is provided around the protruding cylindrical portion 23 provided in the substantially central portion of the bottom plate portion 21 of the lower shell 20. The holding portion 30 includes an inner covering portion 31 that covers a part of the inner surface of the bottom plate portion 21 of the lower shell 20, an outer covering portion 32 that covers a part of the outer surface of the bottom plate portion 21 of the lower shell 20, and a lower shell. The connecting portion 33 is located in the opening 25 provided in the bottom plate portion 20 of the 20 and continues to the inner covering portion 31 and the outer covering portion 32.

  This holding part 30 is an insulating fluid resin material so as to reach from a part of the inner surface of the bottom plate part 21 to a part of the outer surface via an opening 25 provided in the bottom plate part 21 of the lower shell 20. It consists of a resin molded part formed by adhering to the bottom plate part 21 and solidifying it. That is, the holding part 30 is formed by injection molding (more specifically, insert molding) using a mold.

  As a raw material of the holding part 30 formed by injection molding, a resin material excellent in heat resistance, durability, corrosion resistance and the like after curing is suitably selected and used. In that case, it is not limited to a thermosetting resin typified by an epoxy resin or the like, but is typified by a polybutylene terephthalate resin, a polyethylene terephthalate resin, a polyamide resin (for example, nylon 6 or nylon 66), a polypropylene sulfide resin, or a polypropylene oxide resin. It is also possible to use a thermoplastic resin. When these thermoplastic resins are selected as raw materials, it is preferable to contain glass fibers or the like as fillers in these resin materials in order to ensure the mechanical strength of the holding portion 30 after molding. However, when sufficient mechanical strength can be ensured with only the thermoplastic resin, it is not necessary to add the filler as described above.

  The holding portion 30 is fixed to the bottom plate portion 21 on the surface on the bottom plate portion 21 side of each of the inner covering portion 31, the outer covering portion 32, and the connecting portion 33 described above. Here, the holding portion 30 is provided so as to completely cover the protruding cylindrical portion 23 provided on the bottom plate portion 21 of the lower shell 20, whereby the protruding cylindrical portion 23 is completely covered by the holding portion 30. It is in a state of being buried in.

  A holding wall portion 34 having an annular shape is erected toward the top plate portion 11 side at a portion facing the top plate portion 11 of the inner covering portion 31 of the holding portion 30, and is thereby accommodated in the holding portion 30. A recess 35 is provided. The housing recess 35 is a part for receiving a part of the igniter 40 and housing it.

  The holding wall portion 34 having an annular shape has a plurality of locking claw portions 34a provided at the end on the top plate portion 11 side so as to be arranged along the circumferential direction, and the locking claw portions 34a. Each is formed such that its tip faces inward. The plurality of locking claws 34a are portions for fixing the igniter 40 to the holding portion 30 and are portions provided integrally with other portions of the holding portion 30 at the time of injection molding of the holding portion 30. is there.

  In addition, a plurality of locking recesses 34 b are provided on the outer peripheral surface of the holding wall portion 34 so as to be arranged along the circumferential direction at an intermediate position in the vertical direction. The plurality of locking recesses 34 b are provided corresponding to locking claws 52 b provided in the enhancer cup 50 described later, and are portions for fixing the enhancer cup 50 to the holding unit 30. The plurality of locking recesses 34b are portions provided integrally with other portions of the holding portion 30 when the holding portion 30 is injection molded.

  A female connector portion 36 is formed on a portion of the holding portion 30 facing the outside of the outer covering portion 32. The female connector portion 36 is a portion for receiving a male connector (not shown) of a harness for connecting the igniter 40 and a control unit (not shown), and the bottom plate portion 21 of the lower shell 20. It is located in the hollow part 24 provided in. In the female connector portion 36, a portion near the lower end of the terminal pin 42 of the igniter 40 is disposed so as to be exposed. A male connector is inserted into the female connector portion 36, thereby realizing electrical continuity between the harness core wire and the terminal pin 42.

  The connecting portion 33 of the holding portion 30 is provided with a pair of insertion holes 37 having a circular shape in plan view. The pair of insertion holes 37 are portions through which the pair of terminal pins 42 of the igniter 40 are inserted, and both ends thereof reach the housing recess 35 and the female connector 36 described above.

  The igniter 40 is an ignition device for generating a flame, and is provided so as to cover a part of the terminal pin 42 and the pair of terminal pins 42 described above, the above-described pair of terminal pins 42 loaded with the ignition agent. Cover portion 43. The igniting agent loading unit 41 includes therein an igniting agent that generates a flame by igniting and burning during operation, and a resistor for igniting the igniting agent. The pair of terminal pins 42 are connected to the igniting agent loading unit 41 in order to ignite the igniting agent.

  More specifically, the igniting agent loading unit 41 includes a squib cup 41a made of a cup-shaped member, a base 41b that closes an open end of the squib cup 41a, and a pair of terminal pins 42 are inserted and held therein. And a resistor (bridge wire) is attached so as to connect the tips of the pair of terminal pins 42 inserted into the squib cup 41a so as to surround the resistor or close to the resistor. In addition, the squib cup 41a has a configuration in which an igniting agent is loaded. The cover portion 43 covers not only a part of the terminal pin 42 described above but also the base portion 41b.

  Here, nichrome wire or the like is generally used as the resistor, and ZPP (zirconium / potassium perchlorate), ZWPP (zirconium / tungsten / potassium perchlorate), lead tricinate, or the like is generally used as the igniting agent. The squib cup 41a and the base portion 41b are generally made of metal or plastic, and the cover portion 43 is generally made of plastic.

  When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 42. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and the ignition agent starts burning. The high-temperature flame generated by the combustion ruptures the squib cup 41a that stores the ignition agent. The time from when the current flows through the resistor until the igniter 40 is activated is generally 2 milliseconds or less when a nichrome wire is used as the resistor.

  The igniter 40 is fixed to the holding part 30 by fitting a cover part 43, which is a part of the igniter 40, into an accommodation recess 35 provided in the holding part 30. Specifically, the cover portion 43 of the igniter 40 has a portion whose outer shape is formed larger than that of the igniter loading portion 41 (that is, a portion protruding outward in the radial direction). Is held by the holding portion 30 by being sandwiched between the locking claw portion 34 a provided on the holding wall portion 34 and the bottom surface of the receiving recess 35.

  A seal member 45 is interposed between the igniter 40 and the holding unit 30. More specifically, the seal member 45 is disposed between the bottom surface and the inner peripheral surface of the housing recess 35 of the holding unit 30 and the outer peripheral surface of the cover unit 43 of the igniter 40. The seal member 45 is for hermetically sealing a gap generated between the igniter 40 and the holding unit 30 to hermetically seal a combustion chamber 60 described later, and the igniter 40 is assembled to the holding unit 30. At that time, it is inserted into the gap.

  The seal member 45 is preferably made of a material having sufficient heat resistance and durability. For example, an O-ring made of EPDM resin which is a kind of ethylene propylene rubber is preferably used. In addition, if the liquid sealing agent is separately applied to the portion where the sealing member 45 is interposed, the sealing performance of the combustion chamber 60 can be further improved.

  Here, as the liquid sealing agent, those containing a resin material excellent in heat resistance, durability, corrosion resistance and the like after curing are suitably selected and used. As the resin material, for example, cyanoacrylate type Resins and silicone resins are particularly preferably used. In addition to the above resin materials, the above resin materials include phenolic resins, epoxy resins, melamine resins, urea resins, polyester resins, alkyd resins, polyurethane resins, polyimide resins, polyethylene resins. Resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, polytetrafluoroethylene resin, acrylonitrile butadiene styrene resin, acrylonitrile styrene resin, acrylic resin, polyamide resin, polyacetal Resin, polycarbonate resin, polyphenylene ether resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyolefin resin, polyphenylene sulfide resin, polysulfone resin, polyether Sulfone resins, polyarylate resins, polyether ether ketone resin, polyamide-imide resin, liquid crystal polymer, etc. are available.

  An enhancer cup 50 is fixed to the holding unit 30 so as to cover the igniter 40. The enhancer cup 50 has a bottomed cylindrical shape including a top wall portion 51 and a side wall portion 52, and includes a fire transfer chamber 53 in which a charge transfer agent 54 is accommodated. The enhancer cup 50 is fixed to the holding portion 30 so that a fire transfer chamber 53 provided in the enhancer cup 50 faces the igniting agent loading portion 41.

  On the inner peripheral surface of the side wall portion 52 near the opening end of the enhancer cup 50, a plurality of locking claws 52b protruding inward are provided. The plurality of latching claw portions 52b are portions for fixing the enhancer cup 50 to the holding portion 30, and are provided so as to be arranged in the circumferential direction. As a result, the enhancer cup 50 is extrapolated to the holding wall portion 34 provided in the holding portion 30 so that the plurality of locking claw portions 52b described above and the plurality of locking recesses 34b described above are locked. Thus, the holding part 30 is fitted and fixed.

  When the enhancer cup 50 is fixed to the holding unit 30, the enhancer cup 50 completely seals the fire transfer chamber 53 provided therein. The enhancer cup 50 is ruptured or melted as the pressure in the heat transfer chamber 53 rises or conduction of generated heat occurs when the charge 54 is ignited by the operation of the igniter 40. The enhancer cup 50 may be made of a metal member such as aluminum or aluminum alloy, a thermosetting resin typified by an epoxy resin, a polybutylene terephthalate resin, a polyethylene terephthalate resin, a polyamide resin (for example, nylon 6 or nylon 66). Etc.), and those made of a resin member such as a thermoplastic resin typified by polypropylene sulfide resin, polypropylene oxide resin and the like are suitably used.

The transfer charge 54 filled in the transfer chamber 53 is ignited by the flame generated by the operation of the igniter 40 and burns to generate hot particles. The charge transfer agent 54 needs to be able to reliably start the gas generating agent 61 described later, and generally from a metal powder / oxidant represented by B / KNO ₃ or the like. And the like composition is used. As the explosive charge 54, a powdery one, a one formed into a predetermined shape by a binder, or the like is used. Examples of the shape of the charge transfer agent 54 formed by the binder include various shapes such as a granular shape, a columnar shape, a sheet shape, a spherical shape, a single-hole cylindrical shape, a porous cylindrical shape, and a tablet shape.

  A combustion chamber 60 in which the gas generating agent 61 is accommodated is located in a space surrounding the portion in which the enhancer cup 50 is disposed in the space inside the housing formed by the lower shell 20 and the upper shell 10. Yes. More specifically, the above-described enhancer cup 50 is disposed so as to protrude into a combustion chamber 60 formed inside the housing, and is provided at a portion facing the outer surface of the side wall portion 52 of the enhancer cup 50. This space is configured as a combustion chamber 60.

  A filter 70 is disposed along the inner periphery of the housing in a space surrounding the combustion chamber 60 in the radial direction of the housing. The filter 70 has a hollow cylindrical shape, and its central axis is disposed so as to substantially coincide with the axial direction of the housing.

  The gas generating agent 61 is an agent that generates gas by being ignited and burned by hot particles generated when the igniter 40 is operated. As the gas generating agent 61, it is preferable to use a non-azide-based gas generating agent, and the gas generating agent 61 is generally formed as a molded body containing a fuel, an oxidizing agent, and an additive. As the fuel, for example, a triazole derivative, a tetrazole derivative, a guanidine derivative, an azodicarbonamide derivative, a hydrazine derivative, or a combination thereof is used. Specifically, for example, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole and the like are preferably used. The oxidizing agent is selected from basic nitrates such as basic copper nitrate, perchlorates such as ammonium perchlorate and potassium perchlorate, alkali metals, alkaline earth metals, transition metals, and ammonia. Nitrate containing cation is used. As the nitrate, for example, sodium nitrate, potassium nitrate and the like are preferably used. In addition, examples of the additive include a binder, a slag forming agent, and a combustion adjusting agent. As the binder, for example, an organic binder such as a metal salt of carboxymethyl cellulose or a stearate, or an inorganic binder such as synthetic hydroxytalcite or acidic clay can be suitably used. As the slag forming agent, silicon nitride, silica, acid clay, etc. can be suitably used. Moreover, as a combustion regulator, a metal oxide, ferrosilicon, activated carbon, graphite, etc. can be used suitably.

  The shape of the molded body of the gas generating agent 61 includes various shapes such as granular shapes, pellet shapes, granular shapes such as columnar shapes, and disk shapes. In addition, in the cylindrical shape, a porous (for example, a single-hole cylindrical shape or a porous cylindrical shape) having a hole in the molded body is also used. These shapes are preferably selected as appropriate according to the specifications of the airbag apparatus in which the gas generator 1A is incorporated. For example, the shape in which the gas generation rate changes with time during the combustion of the gas generating agent 61 is selected. It is preferable to select an optimal shape according to the specifications. In addition to the shape of the gas generating agent 61, it is preferable to appropriately select the size and filling amount of the molded body in consideration of the linear combustion rate, the pressure index, etc. of the gas generating agent 61.

  The filter 70 is, for example, one obtained by winding and sintering a metal wire such as stainless steel or steel, one obtained by pressing a net material knitted with a metal wire, or by winding a perforated metal plate. Things are used. Here, as the net material, specifically, a knit metal mesh, a plain weave metal mesh, an assembly of crimped metal wires, or the like is used. In addition, as a perforated metal plate, for example, expanded metal that has been cut into a zigzag pattern on the metal plate and expanded to form a hole and processed into a mesh shape, or a hole is formed in the metal plate and at that time A hook metal or the like obtained by flattening the burr generated at the periphery of the hole is used. In this case, the size and shape of the hole to be formed can be appropriately changed as necessary, and holes of different sizes and shapes may be included on the same metal plate. In addition, as a metal plate, a steel plate (mild steel), a stainless steel plate, for example can be used suitably, and nonferrous metal plates, such as aluminum, copper, titanium, nickel, or these alloys, can also be utilized.

  When the gas generated in the combustion chamber 60 passes through the filter 70, the filter 70 functions as a cooling means for cooling the gas by taking away the high-temperature heat of the gas, and a residue contained in the gas. It also functions as a removing means for removing (slag) and the like. Therefore, in order to sufficiently cool the gas and prevent the residue from being discharged to the outside, it is necessary to ensure that the gas generated in the combustion chamber 60 passes through the filter 70.

  A plurality of gas outlets 14 are provided in the upper cylindrical portion 12 at a portion facing the filter 70. The gas outlet 14 is for leading the gas that has passed through the filter 70 to the outside of the housing. A seal tape 15 is affixed to the main surface located on the filter 70 side of the upper cylindrical portion 12 so as to close the gas ejection port 14. As the seal tape 15, an aluminum foil or the like having an adhesive member applied on one side is used. Thereby, the airtightness of the combustion chamber 60 is ensured.

  An upper support member 62 for fixing the upper end of the filter 70 to the housing is disposed at the end of the upper shell 10 on the top plate 11 side in the space inside the housing. The upper support member 62 has a portion that comes into contact with the top plate portion 11 of the upper shell 10 and a portion that comes into contact with the inner peripheral surface of the upper end portion of the filter 70.

  A cushion material 64 is disposed inside the upper support member 62 so as to contact the gas generating agent 61 accommodated in the combustion chamber 60. The cushion material 64 is provided for the purpose of preventing the gas generating agent 61 made of a molded body from being pulverized by vibration or the like, and is preferably a ceramic fiber molded body or foamed resin (for example, foamed silicone). Is used.

  On the other hand, a lower support member 63 for fixing the lower end of the filter 70 to the housing is disposed at the end of the lower shell 20 on the bottom plate portion 21 side in the space inside the housing. The lower support member 63 has a portion that contacts the bottom plate portion 21 of the lower shell 20 and a portion that contacts the inner peripheral surface of the lower end portion of the filter 70.

  The upper side support member 62 and the lower side support member 63 are formed by, for example, pressing a metal plate-like member, and preferably a steel plate such as ordinary steel or special steel (for example, cold steel). For example, a cold rolled steel plate or a stainless steel plate is used. Since the upper side support member 62 and the lower side support member 63 are formed by bending a part of a metal plate-like member as described above, the upper side support member 62 and the lower side support member 63 are Each has moderate elasticity. Therefore, the upper side support member 62 and the lower side support member 63 come into contact with the inner peripheral surface of the filter 70, respectively, and thereby the filter 70 is held and fixed by the housing. Further, each of the upper support member 62 and the lower support member 63 includes a gap between the upper end of the filter 70 and the top plate portion 11 of the upper shell 10, and the lower end of the filter 70 and the bottom plate portion 21 of the lower shell 20. It also functions to prevent the outflow of gas from the gap between the two.

  Next, the operation of the gas generator 1A in the present embodiment will be described with reference to FIG.

  When a vehicle on which the gas generator 1A according to the present embodiment is mounted collides, the collision is detected by a collision detection unit provided separately in the vehicle, and based on this, a control unit provided separately in the vehicle The igniter 40 is activated by energization. The transfer charge 54 accommodated in the transfer chamber 53 is ignited and burned by the flame generated by the operation of the igniter 40, and generates a large amount of heat particles. The enhancer cup 50 is ruptured or melted by the combustion of the explosive 54, and the above-mentioned hot particles flow into the combustion chamber 60.

  The gas generating agent 61 accommodated in the combustion chamber 60 is ignited and burned by the flowing heat particles, and a large amount of gas is generated. The gas generated in the combustion chamber 60 passes through the inside of the filter 70. At this time, heat is taken away and cooled by the filter 70, and slag contained in the gas is removed by the filter 70, and the outside of the housing. Flow into the periphery.

  As the internal pressure of the housing increases, the sealing by the sealing tape 15 that has closed the gas jet port 14 of the upper shell 10 is broken, and gas is jetted out of the housing through the gas jet port 14. The jetted gas is introduced into an airbag provided adjacent to the gas generator 1A, and the airbag is inflated and deployed.

  FIG. 2 is a schematic diagram for explaining an assembling structure and assembling procedure of the upper shell with respect to the lower shell of the gas generator in the present embodiment. Next, referring to FIG. 2 in addition to FIG. 1 described above, the detailed shape of the lower shell 20 of the gas generator 1A in the present embodiment, the details of the finish molding for realizing the shape, and the lower portion The assembly structure and assembly procedure of the upper shell 10 with respect to the side shell 20 will be described.

  As described above, in the gas generator 1A according to the present embodiment, the lower shell 20 presses at least one metal plate member, thereby at least the bottom plate portion 21 and the lower cylindrical portion. 22 is formed by a rough molding, and then a final product is formed only at a necessary portion.

  Of these, finish molding is performed by subjecting the distal end portion of the roughly-formed lower-side cylindrical portion 22 to further pressing. More specifically, as shown in FIGS. 1 and 2, the finish molding is performed by bending the lower shell 20 by pressing so that the entire tip of the roughly molded lower cylindrical portion 22 is bent inward. This is done by processing. Here, the finish molding is performed by pressing the roughly molded lower shell 20 from above using a die having a substantially frustoconical cavity.

  Thus, as shown in FIG. 1, in the state where the lower shell 20 is inserted into the upper shell 10 and press-fitted, the tip of the lower cylindrical portion 22 of the portion inserted into the upper cylindrical portion 12. 22a has a shape bent toward the inside. Therefore, the outer peripheral surface of the tip 22 a of the lower cylindrical portion 22 of the portion inserted into the upper cylindrical portion 12 is inclined inward so as to retract from the inner peripheral surface of the upper cylindrical portion 12. At the same time, the outer peripheral surface of the portion of the lower cylindrical portion 22 inserted into the upper cylindrical portion 12 excluding the distal end portion 22a comes into contact with the inner peripheral surface of the upper cylindrical portion 12. become.

  Here, referring to FIG. 2, the angle θ formed by the outer peripheral surface of the tip 22a of the lower cylindrical portion 22 and the outer peripheral surface of the portion excluding the tip 22a is greater than 0 ° and 10 ° or less. Preferably, the angle is about 7 °. If it does in this way, it will become possible to bend the front-end | tip part 22a of the lower side cylindrical part 22 without enlarging the external dimension of a housing.

  When assembling, as shown in FIG. 2, a seal tape 15 is previously affixed to the upper shell 10, and an igniter 40, an enhancer cup 50, a filter 70, etc. are attached to the lower shell 20 as shown in the figure. Various components are assembled, and the upper shell 10 is fitted into the lower shell 20 assembled with the various components from above.

  As a result, the lower shell 20 is inserted into the upper shell 10 by inserting the opening end of the lower cylindrical portion 22 of the lower shell 20 inside the opening end of the upper cylindrical portion 12 of the upper shell 10. It will be press-fitted. At that time, since the tip 22a of the lower cylindrical portion 22 has a shape bent inward, the contact between the upper shell 10 and the lower shell 20 is smoothly performed.

  As described above, by press-fitting so that the outer peripheral surface of the lower cylindrical portion 22 excluding the tip portion 22a reaches at least the position where it contacts the inner peripheral surface of the upper cylindrical portion 12. Since the upper cylindrical portion 12 and the lower cylindrical portion 22 are in close contact with each other after the press-fitting, the airtightness inside the housing is sufficiently ensured.

  After the press-fitting, the upper shell 10 and the lower shell 20 are joined by performing a welding process on these boundary portions from the outside. In this way, the gas generator 1A as shown in FIG. 1 is manufactured.

  In the gas generator 1A according to the present embodiment described above, the upper shell 10 is molded by pressing, and the rough molding and finish molding of the lower shell 20 are performed by pressing. The surfaces of both the side shell 10 and the lower shell have forged skin. Accordingly, when the lower shell 20 is press-fitted into the upper shell 10, the forged skins come into contact with each other. Compared with the case where it becomes, generation | occurrence | production of a burr | flash can be suppressed significantly.

  In addition, as described above, in the gas generator 1A according to the present embodiment, the tip 22a of the lower cylindrical portion 22 of the lower shell 20 has a shape bent inward, From the viewpoint, the corner of the upper cylindrical portion 12 of the upper shell 10 and the corner of the lower cylindrical portion 22 of the lower shell 20 do not contact each other, and press fitting can be performed smoothly. However, the generation of burrs can be suppressed.

  Therefore, by adopting the above configuration, not only the effect that the gas generator 1A can be manufactured at low cost by the lower shell 20 being manufactured by press working is obtained, but also at the time of assembly. Since it is possible to suppress the occurrence of burrs in the housing, it is possible to obtain an effect that it is possible to prevent the occurrence of malfunctions such as poor housing joining and malfunctions that cause the igniter to malfunction. it can.

  In the present embodiment described above, the entire distal end portion of the lower tubular portion 22 is bent so that the distal end portion 22a of the lower tubular portion 22 inserted into the upper tubular portion 12 is bent. Although the case where the outer peripheral surface is configured to incline inward is illustrated, the lower side cylinder of the portion inserted into the upper side cylindrical portion 12 by curving the entire distal end portion of the lower side cylindrical portion 22 You may comprise so that the outer peripheral surface of the front-end | tip part 22a of the shape part 22 may incline toward inner side.

(Embodiment 2)
FIG. 3 is a schematic diagram of a gas generator according to Embodiment 2 of the present invention. Below, with reference to this FIG. 3, the gas generator 1B in this Embodiment is demonstrated.

  As shown in FIG. 3, the gas generator 1 </ b> B in the present embodiment is lower than the portion inserted into the upper cylindrical portion 12, as compared with the gas generator 1 </ b> A in the first embodiment of the present invention described above. The only difference is that the distal end portion 22a of the side cylindrical portion 22 extends to a position that covers the gas outlet 14 provided in the upper side cylindrical portion 12. That is, in the gas generator 1B according to the present embodiment, the distal end portion 22a of the lower cylindrical portion 22 faces the gas outlet 14 along the radial direction of the housing. The length along the axial direction of the housing is increased.

  With this configuration, the gas generated in the combustion chamber 60 during operation bypasses the tip 22a of the lower cylindrical portion 22 in the space inside the housing and outside the filter 70. Therefore, the gas flow path in the space becomes complicated. Therefore, even when there is slag that cannot be completely removed by the filter 70, it can be efficiently collected in the portion, and the amount of slag contained in the gas discharged from the gas generator 1B is further increased. Can be reduced. Therefore, by adopting this configuration, a higher performance gas generator can be obtained.

(Embodiment 3)
FIG. 4 is a schematic diagram of a gas generator according to Embodiment 3 of the present invention. FIG. 5 is an enlarged view of a main part of the gas generator in the present embodiment, and shows a region V shown in FIG. Below, with reference to these FIG. 4 and FIG. 5, 1 C of gas generators in this Embodiment are demonstrated.

  As shown in FIGS. 4 and 5, the gas generator 1C according to the present embodiment is inserted into the upper cylindrical portion 12 as compared with the gas generator 1A according to the first embodiment of the present invention described above. It differs only in the shape of the front-end | tip part 22a of the lower side cylindrical part 22 of a part. Here, even in the gas generator 1 </ b> C in the present embodiment, the lower shell 20 presses at least one bottom plate portion 21 and the lower cylindrical portion 22 by pressing one metal plate member. Rough molding is performed, and thereafter, finish molding is performed only at necessary portions, and the molded product is manufactured.

  Of these, finish molding is performed by subjecting the distal end portion of the lower-side cylindrical portion 22 that has been roughly molded to further pressing or cutting. More specifically, as shown in FIGS. 4 and 5, the finish molding is performed so that corners located on the outer peripheral surface side of the distal end portion of the roughly-formed lower side cylindrical portion 22 are removed. A chamfering process is performed by pressing or a chamfering process by cutting.

  Thus, in a state where the lower shell 20 is inserted into the upper shell 10 and press-fitted, the outer peripheral surface of the distal end portion 22a of the lower cylindrical portion 22 of the portion inserted into the upper cylindrical portion 12 is the upper portion. The tip end portion of the lower cylindrical portion 22 of the portion inserted into the upper cylindrical portion 12 is inclined inwardly so as to retract from the inner peripheral surface of the side cylindrical portion 12. The outer peripheral surface of the portion excluding 22a comes into contact with the inner peripheral surface of the upper cylindrical portion 12.

  In the gas generator 1C in the present embodiment described above, the upper shell 10 is formed by pressing, and the lower shell 20 is roughly formed by pressing, and the lower shell 20 is formed. Since the finish molding is performed by pressing or cutting, the press-fit surfaces of the upper shell 10 and the lower shell (that is, the inner peripheral surface of the upper cylindrical portion 12 and the outer peripheral surface of the lower cylindrical portion 22). All have forged skin. Accordingly, when the lower shell 20 is press-fitted with respect to the upper shell 10, the forged skins come into contact with each other. Therefore, either or both of these press-fitting surfaces are cut by cutting or the like. The occurrence of burrs can be significantly suppressed as compared to the case of skin.

  In addition, in the gas generator 1C according to the present embodiment, the portion corresponding to the corner on the outer peripheral surface side of the distal end portion 22a of the lower cylindrical portion 22 of the lower shell 20 has a curved shape. Therefore, the press-fitting can be performed smoothly, and the generation of burrs can be suppressed from this viewpoint. When the finish molding is performed by cutting, a portion corresponding to a corner on the outer peripheral surface side of the tip 22a of the lower cylindrical portion 22 has a cut skin. Even when the corner portion of the upper cylindrical portion 12 of the upper shell 10 contacts the corner portion, the corner portion is immediately guided to the press-fitting surface of the forging skin which is the outer peripheral surface of the lower cylindrical portion 22 of the lower shell 20. Therefore, the possibility of occurrence of burrs is very low.

  Therefore, by adopting the above configuration, it is possible to obtain the same effect as that described in the first embodiment of the present invention described above, the manufacturing cost can be reduced, and the burr generated in the housing at the time of assembly can be reduced. It can be set as the gas generator which can suppress generation | occurrence | production.

  In the above-described embodiment, the portion corresponding to the corner of the tip 22a of the lower cylindrical portion 22 is curved so that the portion of the lower cylinder inserted into the upper cylindrical portion 12 is curved. The case where the outer peripheral surface of the distal end portion 22a of the cylindrical portion 22 is configured to be inclined inward is illustrated, but a portion corresponding to a corner portion of the distal end portion 22a of the lower cylindrical portion 22 is inclined in a planar shape. Thus, the outer peripheral surface of the distal end portion 22a of the lower-side cylindrical portion 22 of the portion inserted into the upper-side cylindrical portion 12 may be configured to be inclined inward.

(Embodiment 4)
FIG. 6 is a schematic diagram of a gas generator according to Embodiment 4 of the present invention. Below, with reference to this FIG. 6, gas generator 1D in this Embodiment is demonstrated.

  As shown in FIG. 6, the gas generator 1 </ b> D in the present embodiment is lower than the portion inserted into the upper cylindrical portion 12, as compared with the gas generator 1 </ b> C in the third embodiment of the present invention described above. The distal end portion 22a of the side tubular portion 22 has an extending portion 22a1 that extends from the inner portion of the distal end portion 22a to a position that covers the gas jet port 14 provided in the upper side tubular portion 12. The only difference is that

  Here, in the gas generator 1D according to the present embodiment, the lower shell 20 presses a single metal plate-shaped member to roughly form at least the bottom plate portion 21 and the lower cylindrical portion 22. After that, it is composed of a molded product that is manufactured by performing finish molding only at a necessary portion. Of these, the finish molding is performed at the tip of the roughly-formed lower side cylindrical portion 22. This is done by cutting.

  More specifically, after the lower cylindrical portion 22 is roughly molded so that the tip portion thereof has a height facing the gas outlet 14, in the finish molding, the roughly molded lower side The outer portion of the tip portion is removed so as to leave the inner portion of the tip portion of the cylindrical portion 22, and the corner portion that is positioned on the outer peripheral surface side by removing the outer portion is also removed. By performing the chamfering process by cutting, the shape of the tip of the lower cylindrical portion 22 is formed as shown in FIG.

  Thereby, in gas generator 1D in this Embodiment, the extension part 22a1 of the front-end | tip parts 22a of the lower side cylindrical part 22 faces the gas jet nozzle 14 along the radial direction of a housing. It becomes.

  Therefore, by adopting the above configuration, it is possible to obtain the same effect as that described in the second embodiment of the present invention, and even when there is slag that cannot be removed by the filter 70, Can be efficiently collected in the extending portion 22a1 of the lower-side cylindrical portion 20, and the amount of slag contained in the gas discharged from the gas generator 1D can be further reduced. It can be a high performance gas generator.

  In Embodiments 1 to 4 of the present invention described above, the case where the upper shell is configured by a press-formed product has been described as an example. However, the upper shell need not necessarily be a press-formed product. Alternatively, the upper shell may be manufactured by cutting or the like. In that case, the press-fitting surface of the upper shell has a cut skin, but at least the press-fitting surface of the lower shell has a forging skin, so that the occurrence of burrs is considerably suppressed. .

  Moreover, in Embodiment 1 thru | or 4 of this invention demonstrated above, the opening end of the lower side cylindrical part of a lower side shell is inserted inside the opening end of the upper side cylindrical part of an upper side shell. However, the opening end of the lower cylindrical portion of the lower shell is located outside the opening end of the upper cylindrical portion of the upper shell. It may be configured such that the lower shell is press-fitted into the upper shell by being inserted. In that case, the lower shell corresponds to the first shell, and the upper shell corresponds to the second shell.

  Further, the specific shape of the protruding cylindrical portion provided in the lower shell disclosed in the first to fourth embodiments of the present invention described above, and the specific shape of the holding portion provided on the lower shell. The specific shapes of the igniter and the enhancer cup assembled to the holding unit, the specific assembly structure, and the like are merely examples, and can be appropriately changed.

  Thus, the above-described embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1A to 1D Gas generator, 10 Upper shell, 11 Top plate, 12 Upper cylinder, 13 Flange, 14 Gas outlet, 15 Seal tape, 20 Lower shell, 21 Bottom plate, 22 Lower cylinder Shaped part, 22a tip part, 22a1 extending part, 23 projecting cylindrical part, 24 recessed part, 25 opening part, 30 holding part, 31 inner covering part, 32 outer covering part, 33 connecting part, 34 holding wall part, 34a Locking claw portion, 34b Locking recess, 35 receiving recess, 36 female connector portion, 37 insertion hole, 40 igniter, 41 ignition charge loading portion, 41a squib cup, 41b base portion, 42 terminal pin, 43 cover portion, 45 Seal member, 50 Enhancer cup, 51 Top wall, 52 Side wall, 52b Locking claw, 53 Fire transfer chamber, 54 Transfer charge, 60 Combustion chamber, 61 Gas generating agent, 62 Top Part side support member, 63 Lower side support member, 64 cushion material, 70 filter, W welding trace.

Claims (7)

A short cylindrical housing that includes a combustion chamber in which a gas generating agent is housed, and is constituted by a top plate portion and a bottom plate portion that close an axial end portion, and a peripheral wall portion provided with a gas jet port;
An igniter for burning the gas generating agent,
The housing has a first shell and a second shell made of a bottomed cylindrical metal member,
The first shell includes a first plate-like portion constituting one of the top plate portion and the bottom plate portion, and a first tubular portion constituting a portion of the peripheral wall portion on the first plate-like portion side. Including
The second shell includes a second plate-like portion constituting the other of the top plate portion and the bottom plate portion, and a second tubular portion constituting a portion of the peripheral wall portion on the second plate-like portion side. Including
The igniter is assembled to one of the first plate portion and the second plate portion,
The second shell is a molded product in which at least the second plate-shaped portion and the second cylindrical portion are roughly formed by pressing a single metal plate-shaped member, and the second shell The opening end of the cylindrical part is press-fitted into the first shell by being inserted inside the opening end of the first cylindrical part,
The outer peripheral surface of the distal end portion of the second cylindrical portion of the portion inserted into the first cylindrical portion is inclined inward so as to retract from the inner peripheral surface of the first cylindrical portion, and The gas generator, wherein an outer peripheral surface of a portion inserted into the first cylindrical portion excluding the tip portion of the second cylindrical portion is in contact with an inner peripheral surface of the first cylindrical portion.   The gas generator according to claim 1, wherein the finish forming of the tip end portion is performed by pressing the tip end portion of the roughly-formed second cylindrical portion.   The finish molding of the tip portion is performed by subjecting the second shell to a bending process by pressing so that the entire tip portion of the roughly-formed second cylindrical portion is bent or curved inward. The gas generator according to claim 2.   The gas generator according to claim 3, wherein the distal end portion extends to a position covering the gas ejection port provided in the peripheral wall portion.   In the finish molding of the tip portion, the second shell is subjected to a chamfering process by pressing so that the corner portion located on the outer peripheral surface side of the tip portion of the second cylindrical portion is roughly removed. The gas generator according to claim 2, wherein the gas generator is performed.   In the finish molding of the tip portion, the second shell is subjected to a chamfering process by cutting so that a corner portion located on the outer peripheral surface side of the tip portion of the roughly cylindrical second portion is removed. The gas generator according to claim 1, wherein   The gas generator according to claim 6, wherein the distal end portion has an extending portion that extends from an inner portion of the distal end portion to a position that covers the gas ejection port provided in the peripheral wall portion. .

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