JP6681772B2 - Gas generator - Google Patents

Description

  The present invention relates to a gas generator incorporated in an occupant protection device that protects an occupant in the event of a vehicle collision, and more particularly to a gas generator incorporated in an airbag device installed in an automobile or the like.

  2. Description of the Related Art Conventionally, from the viewpoint of protecting an occupant of an automobile or the like, an airbag device which is an occupant protection device has been widely used. The airbag device is provided for the purpose of protecting an occupant from a shock generated when a vehicle or the like collides, and the airbag serves as a cushion by inflating and deploying the airbag instantaneously when the vehicle or the like collides. It is the one that receives the body.

  The gas generator is incorporated in this airbag device, and when a vehicle or the like collides, the control unit energizes the igniter to ignite it, and the flame generated in the igniter burns the gas generant to instantly generate a large amount of gas. This is a device for inflating and deploying an airbag.

  There are various types of gas generators, but as a gas generator that can be suitably used for a driver side airbag device, a passenger side airbag device, etc., a short, generally cylindrical shape with a relatively large outer diameter. As a gas generator that can be used suitably for side airbag devices, curtain airbag devices, knee airbag devices, etc., there is a disk type gas generator of There is a vessel.

  In a gas generator, it is important to stably and continuously burn the gas generating agent during operation. In order to stably and continuously burn the gas generating agent, it is necessary to place the gas generating agent in a predetermined high pressure environment. Therefore, in the gas generator, a plurality of gas ejection ports provided in the housing are provided. Is designed to increase the pressure of the space inside the housing to a considerable extent during operation by reducing the size of the to a desired size.

  However, the output characteristics of the gas generator are affected by the surrounding environment in which the gas generator is placed, and particularly depend on the environmental temperature, and the output characteristics are strengthened in a high temperature environment and weakened in a low temperature environment. There is a tendency. That is, in the high temperature environment, the gas is ejected faster and stronger, and in the low temperature environment, the gas is ejected slower and weaker. Therefore, especially in a low temperature environment, the pressure inside the housing is likely to drastically drop due to the opening of the gas ejection port, which hinders the continuous combustion of the gas generating agent and causes a shortage of gas output. May occur.

  For the purpose of reducing the difference in gas output performance due to the ambient temperature, for example, in International Publication No. WO 2015/163290 (Patent Document 1), the opening pressure is set as a plurality of gas ejection ports provided in a housing. Disc type gas generators configured to include different ones are disclosed. In the gas generator configured as described above, the plurality of gas ejection ports are opened stepwise as the pressure in the space inside the housing rises.

  Therefore, compared with a gas generator configured to open all the gas jets all at once as the pressure in the space inside the housing rises, a large drop in internal pressure rise occurs especially in a low temperature environment. Can be prevented. Therefore, it is possible to continuously burn the gas generant in any temperature environment from a high temperature environment to a low temperature environment, and as a result, it is possible to reduce the difference in gas output performance due to the environmental temperature. It will be possible.

  It should be noted that, in FIGS. 10 to 12 of the above-mentioned Patent Document 1, by providing a plurality of gas ejection ports whose opening pressures are set in three stages in the peripheral wall portion of the housing, the space inside the housing during operation is Disclosed is a disk-type gas generator configured so that a plurality of gas ejection ports are opened in three stages as the pressure rises. Here, in consideration of general specifications required for the disk-type gas generator, it is preferable that the plurality of gas ejection ports are set to be opened in three stages as described above.

International Publication No. 2015/163290

  On the other hand, in recent years, there has been a strong demand for reducing the size and weight of gas generators. In order to reduce the size and weight of the gas generator, it is effective to reduce the thickness of the housing, which is a pressure container. However, if the thickness of the housing is simply reduced, the pressure resistance of the housing will not be sufficient. You will not be able to secure it. Therefore, in order to reduce the size and weight of the gas generator, the pressure of the space inside the housing during operation should be lowered to a considerable extent within the range where the gas generating agent can stably and continuously burn. Indispensable.

  In order to reduce the pressure of the space inside the housing during operation, it is conceivable to increase the total opening area of the gas outlets provided over a plurality of them, but simply increase the opening area of each gas outlet. In this case, the pressure in the space inside the housing cannot be increased during operation. Therefore, it is effective to increase the number of each of the plurality of gas ejection ports provided in the housing while suppressing the opening area of each of the gas ejection ports to be small.

  Here, in the disk-type gas generator disclosed in FIG. 10 to FIG. 12 of Patent Document 1, a total of eight gas ejection ports are provided only on the peripheral wall portion of the housing. There is still room for improvement in reducing the size and weight of the gas generator.

  Further, in the disk-type gas generator disclosed in FIGS. 10 to 12 of the above-mentioned Patent Document 1, a total of eight gas ejection ports are provided uniformly along the circumferential direction of the peripheral wall portion of the housing, The two gas outlets with the smallest opening pressure are arranged with 180 [°] rotational symmetry about the axis of the peripheral wall of the housing, and the four gas outlets with the second smallest opening pressure are The two gas outlets, which are arranged with a rotational symmetry of 90 [°] about the axis of the peripheral wall of the housing and have the largest opening pressure, have 180 [°] about the axis of the peripheral wall of the housing. It is arranged with rotational symmetry.

  Here, when the gas generator is in operation, a large thrust acts on the gas generator by the gas ejected from the gas ejection port. Therefore, in the unlikely event that the fixing force of the fixing member that fixes the gas generator (for example, the retainer of the airbag device) is insufficient (for example, the decrease in the fixing force due to aging), the safety during operation May not be secured.

  In this respect, in the disk-type gas generator disclosed in FIGS. 10 to 12 of Patent Document 1, the gas outlets that are opened at the same time are arranged at opposite positions with the axial line of the peripheral wall of the housing interposed therebetween. , The thrusts to be applied to the gas generator due to the gas ejected from the gas ejection port cancel each other out, and it becomes substantially the same as the state where no external force is applied to the disk-type gas generator. Therefore, the safety during operation can be secured.

  However, immediately after the two gas outlets having the smallest opening pressure are opened (see FIG. 12A of Patent Document 1), gas is generated only at two positions in the circumferential direction of the peripheral wall of the housing. If the fixing force of the fixing member that fixes the gas generator is insufficient at only some positions in the circumferential direction of the housing, as it will be ejected, the thrust force applied to the gas generator will be balanced. Is likely to collapse, and if this is disrupted, a large external force will be applied to the disk-type gas generator, and there is room for further improvement in this respect.

  Immediately after the opening of the four gas outlets having the next smallest opening pressure (see FIG. 12B of the above-mentioned Patent Document 1), there is a bias in two positions in the circumferential direction of the peripheral wall of the housing. Since gas will be ejected, it can be said that there is room for further improvement, as in the case described above.

  In addition, immediately after the two gas outlets with the smallest opening pressure are opened and immediately after the four gas outlets with the next smallest opening pressure are opened, the airbag is still fully deployed. No, so the distance between the opened gas outlet and the airbag is very close. Therefore, in the disk-type gas generator disclosed in FIGS. 10 to 12 of the above-mentioned Patent Document 1, from two positions in the circumferential direction of the peripheral wall portion of the housing or two positions deviated in the circumferential direction including these positions. Due to the configuration that the gas is ejected, the ejected high-temperature and high-pressure gas may be concentrated and ejected on a local part of the airbag, resulting in damage to the airbag. There is room for improvement in this respect as well.

  Here, in order to reduce the size and weight of the gas generator, a configuration in which the number of individual gas ejection ports provided in the housing is increased and the number of the gas ejection ports is increased is shown in FIG. Even when it is applied to the disk-type gas generator disclosed in FIG. 12, each of the plurality of gas ejection ports of which the number is increased is arranged in any position on the peripheral wall portion of the housing and in any order. There will be a big difference in performance depending on whether or not to do so.

  Therefore, the present invention has been made in view of the above problems, can be reduced in size and weight, can reduce the difference in performance of gas output due to the environmental temperature, further safety during operation. It is an object of the present invention to provide a gas generator that is improved and the damage to the airbag is reduced.

A gas generator according to the present invention includes a housing, a gas generating agent, an igniter, and a seal member. The housing has a cylindrical peripheral wall portion provided with a plurality of gas ejection ports, and one end portion and the other end portion in the axial direction of the peripheral wall portion are closed. The gas generating agent is arranged in a housing space located inside the housing. The igniter is for burning the gas generating agent, and is attached to the housing. The seal member closes the plurality of gas ejection ports. The plurality of gas ejection ports is composed of a plurality of gas ejection port groups. The plurality of sets of gas outlets are evenly arranged along the circumferential direction of the peripheral wall portion so as to have rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall portion. One or more groups of first gas outlets having a plurality of first gas outlets having a first opening pressure, and rotational symmetry with an angle of 120 [°] or less about the axis of the peripheral wall. 1 group or 2 or more groups of 2nd gas jets which are evenly arranged along the circumferential direction of the said peripheral wall part and which have a mutually same 2nd opening pressure and which have the same 2nd opening pressure. And a plurality having the same third opening pressures that are evenly arranged along the circumferential direction of the peripheral wall so as to have rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall. One set consisting of the third gas outlet of And two or more sets of the third gas jet port group has only. The second opening pressure is higher than the first opening pressure, and the third opening pressure is higher than the second opening pressure. The plurality of gas ejection ports are arranged in a line along the circumferential direction of the peripheral wall so as not to overlap each other in the circumferential direction of the peripheral wall . The sealing member is composed of at least one sealing tape attached to the inner peripheral surface of the peripheral wall portion. In the gas generator according to the present invention, when the plurality of gas ejection ports are viewed as a whole, the plurality of gas ejection ports are evenly arranged along the circumferential direction of the peripheral wall portion. By not doing so, the maximum width wall region where the linear distance between the end portions of the gas outlets adjacent to each other in the circumferential direction of the peripheral wall portion of the plurality of gas outlets becomes the circumference of the peripheral wall portion. A plurality of them are provided on the peripheral wall along the direction. The pair of end portions located in the extending direction of the sealing tape are located in any of the plurality of maximum width wall regions. At least one of the plurality of first gas ejection ports, the plurality of second gas ejection ports, and the plurality of third gas ejection ports is an elongated hole-shaped gas ejection port. In the gas generator based on the present invention, when the gas generator is operated in a low temperature environment where the ambient temperature is -40 [° C], the plurality of elongated hole-shaped gas ejection ports are closed. At the time of the seal member cleaving, at least a part of the sealing member of the portion that closes the plurality of elongated hole-shaped gas ejection ports is provided on the entire circumference of the opening edge portion of the elongated hole-shaped gas ejection port. It does not completely break along and is attached to a part of the opening edge portion after the cleavage.

  Here, when determining the above-described gas ejection port group, the gas ejection port group is determined so that as many gas ejection ports as possible constitute one group of gas ejection ports. That is, for example, when four gas ejection ports having the same opening pressure are provided along the circumferential direction on the peripheral wall portion of the housing, these are arranged with rotational symmetry of 180 [°]. A total of two sets of gas jets consisting of one gas jet group and a gas jet group consisting of two gas jets arranged with 180 [°] rotational symmetry. Although it can be considered that it is configured, it is not considered as such, and in this case, it is composed of four gas ejection ports arranged with rotational symmetry of 90 [°]. It is assumed that it is composed of a set of gas ejection ports.

In the gas generator based on the present invention, the maximum width wall region, preferably a 7.0 [mm] or more der Turkey.

  In the gas generator based on the present invention, the sealing tape is one strip-shaped member attached to the inner peripheral surface of the peripheral wall portion such that the extending direction thereof coincides with the peripheral direction of the peripheral wall portion. It is preferable that the pair of end portions located in the extending direction of the one band-shaped seal tape is one of the plurality of wall regions. It is preferable that they are located in one place.

In the gas generator based on the present invention, each of the plurality of elongated hole-shaped gas ejection ports extends along the axial direction of the peripheral wall portion rather than the opening width along the circumferential direction of the peripheral wall portion. It is preferable to have a long hole shape with a large opening width.

  In the gas generator based on the present invention, all the gas outlets other than the gas outlets included in the third gas outlet group out of the plurality of gas outlets are the peripheral walls. It is preferable that the portions are evenly arranged along the circumferential direction.

  In the gas generator based on the present invention, the sum of the opening areas of each of the plurality of first gas jets is equal to the sum of the opening areas of each of the plurality of second gas jets. It is preferably smaller than the sum of the sum of the opening areas of the individual third gas ejection ports.

In the gas generator based on the present invention, at least one of the plurality of first gas ejection ports, the plurality of second gas ejection ports, and the plurality of third gas ejection ports, When the opening area of one gas outlet is S [mm ² ] and the circumferential length of the one gas outlet is C [mm], S and C are S / C ≦ 0.27. It is preferable to have a shape that satisfies the condition of × S ^0.5 .

  According to the present invention, it is possible to reduce the size and weight, reduce the difference in gas output performance due to the ambient temperature, and further improve the safety during operation and reduce the damage to the airbag. Can be a gas generator.

FIG. 3 is a front view of the disk type gas generator in the first embodiment of the present invention. It is a schematic sectional drawing of the disc type gas generator shown in FIG. FIG. 3 is a cross-sectional view of an upper shell and a sealing tape taken along line III-III shown in FIGS. 1 and 2. It is an enlarged view of the 1st thru | or 3rd gas ejection port shown in FIG. 1 and FIG. It is the figure which represented typically the mode that the gas ejection port was opened in steps at the time of the operation of the gas generator in the embodiment of the present invention. It is the figure which represented typically the state of the gas injection nozzle vicinity at the time of the operation of the gas generator in embodiment of this invention. It is a front view of the disk type gas generator in Embodiment 2 of the present invention. FIG. 8 is a cross-sectional view of the upper shell and the sealing tape taken along the line VIII-VIII shown in FIG. 7. FIG. 7 is a cross-sectional view of an upper shell and a seal tape of a disk type gas generator according to a third embodiment of the present invention. It is an enlarged view of the 1st thru | or 3rd gas ejection port shown in FIG. FIG. 11 is a cross-sectional view of an upper shell and a seal tape of a disk type gas generator according to a fourth embodiment of the present invention. It is an enlarged view of the 1st thru | or 3rd gas ejection port shown in FIG.

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

(Embodiment 1)
FIG. 1 is a front view of a disk-type gas generator according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of the disk-type gas generator shown in FIG. First, the configuration of the disk-type gas generator 1A according to the present embodiment will be described with reference to FIGS. 1 and 2.

  As shown in FIGS. 1 and 2, the disk-type gas generator 1A according to the present embodiment has a short, substantially cylindrical housing with one axial end and the other axial end closed. A holding portion 30, an igniter 40, a cup-shaped member 50, a transfer charge 56, a gas generating agent 61, a lower side supporting member 70, an upper side supporting member 80, a cushion, which are internal components, are provided in an accommodation space provided inside the The material 85, the filter 90, and the like are housed therein. Further, in the accommodation space provided inside the housing, the combustion chamber 60 in which the gas generating agent 61 of the above-mentioned internal components is mainly accommodated is located.

  The short, substantially cylindrical housing includes a lower shell 10 and an upper shell 20. Each of the lower shell 10 and the upper shell 20 is a press-formed product formed by pressing a rolled metal plate member, for example. As the metal plate-shaped member forming the lower shell 10 and the upper shell 20, for example, a metal plate made of stainless steel, steel, aluminum alloy, stainless alloy, or the like is used, and preferably 440 [MPa] or more and 780 or more. A so-called high-tensile steel plate that does not cause damage such as breakage even when a tensile stress of [MPa] or less is applied is used.

  The lower shell 10 and the upper shell 20 are each formed in a substantially cylindrical shape with a bottom, and the housing is formed by combining and joining the opening surfaces so as to face each other. The lower shell 10 has a bottom plate portion 11 and a peripheral wall portion 12, and the upper shell 20 has a top plate portion 21 and a peripheral wall portion 22. As a result, one end and the other end of the housing in the axial direction are closed by the bottom plate portion 11 and the top plate portion 21, respectively. For joining the lower shell 10 and the upper shell 20, electron beam welding, laser welding, friction welding, or the like can be suitably used.

  As shown in FIG. 2, the bottom shell 11 of the lower shell 10 is provided with a projecting tubular portion 13 projecting toward the top plate 21 at the center thereof, whereby the bottom shell of the lower shell 10 is provided. A recess 14 is formed in the center of the portion 11. The protruding cylindrical portion 13 is a portion to which the igniter 40 is fixed via the holding portion 30 described above, and the recess portion 14 is a portion to be a space for providing the female connector portion 34 in the holding portion 30. .

  The protruding cylindrical portion 13 is formed in a substantially cylindrical shape having a bottom, and an axial end portion thereof located on the side of the top plate portion 21 has an asymmetrical shape (for example, a D shape, a barrel) in a plan view. An opening 15 having a mold shape, an oval shape, or the like) is provided. The opening 15 is a portion into which the pair of terminal pins 42 of the igniter 40 are inserted.

  The igniter 40 is for generating a flame, and includes an ignition unit 41 and the pair of terminal pins 42 described above. The igniting unit 41 includes, inside thereof, an ignition charge that ignites and burns during operation to generate a flame, and a resistor for igniting the ignition charge. The pair of terminal pins 42 are connected to the ignition part 41 for igniting the ignition charge.

  More specifically, the ignition part 41 includes a squib cup formed into a cup shape, and a base part that closes the open end of the squib cup and that holds the pair of terminal pins 42 inserted therethrough. A resistor (bridge wire) is attached so as to connect the tips of the pair of terminal pins 42 inserted in the squib cup, and is pointed in the squib cup so as to surround the resistor or close to the resistor. It has a configuration loaded with gunpowder.

  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 ignition charge. The above-mentioned squib cup and base are generally made of metal or 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 charge starts burning. The hot flame produced by the combustion bursts the squib cup containing the ignition charge. The time from the current flowing through the resistor until the igniter 40 is activated is generally 2 milliseconds or less when a nichrome wire is used for the resistor.

  The igniter 40 is attached to the bottom plate portion 11 in a state of being inserted from the inside of the lower shell 10 so that the terminal pin 42 is inserted into the opening 15 provided in the protruding tubular portion 13. Specifically, a holding portion 30 made of a resin molding portion is provided around the protruding cylindrical portion 13 provided on the bottom plate portion 11, and the igniter 40 is held by the holding portion 30. Is fixed to the bottom plate portion 11.

  The holding portion 30 is formed by injection molding (more specifically, insert molding) using a mold, and the bottom plate portion 11 passes through an opening 15 provided in the bottom plate portion 11 of the lower shell 10. It is formed by adhering an insulative fluid resin material to the bottom plate 11 and solidifying it so as to reach a part of the inner surface to a part of the outer surface.

  The igniter 40 is in a state of being inserted from the inside of the lower shell 10 so that the terminal pin 42 is inserted into the opening 15 when the holding portion 30 is molded, and in this state, the igniter 40 and the lower shell 10 are inserted. The fluid resin material described above is poured so as to fill the space between the bottom plate 11 and the bottom plate 11 via the holding part 30.

  As a raw material of the holding portion 30 formed by injection molding, a resin material having excellent 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, 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, a polypropylene oxide resin, or the like. It is also possible to use a thermoplastic resin. When these thermoplastic resins are selected as the raw materials, it is preferable that these resin materials contain glass fiber or the like as a filler in order to secure the mechanical strength of the holding portion 30 after molding. However, when sufficient mechanical strength can be secured only with the thermoplastic resin, it is not necessary to add the filler as described above.

  The holding portion 30 includes an inner coating portion 31 that covers a part of the inner surface of the bottom plate portion 11 of the lower shell 10, an outer coating portion 32 that covers a part of the outer surface of the bottom plate portion 11 of the lower shell 10, and a lower portion. The side shell 10 has a connecting portion 33 located in the opening 15 provided in the bottom plate portion 11 and continuous with the inner coating portion 31 and the outer coating portion 32, respectively.

  The holding part 30 is fixed to the bottom plate part 11 on the surface of the inner covering part 31, the outer covering part 32, and the connecting part 33 on the bottom plate part 11 side. Further, the holding portion 30 is respectively fixed to the side surface and the lower surface of the portion of the igniter 40 near the lower end of the igniter 41 and the surface of the portion of the igniter 40 near the upper end of the terminal pin 42. As a result, the opening 15 is completely embedded by the terminal pin 42 and the holding portion 30, and the airtightness of the space inside the housing is ensured by ensuring the sealing property at that portion. Since the opening 15 is formed in a non-point-symmetrical shape in plan view as described above, by embedding the opening 15 with the connecting portion 33, the opening 15 and the connecting portion 33 are retained by the holding portion 30. Also functions as a rotation preventing mechanism that prevents the rotation of the bottom plate 11 with respect to the bottom plate 11.

  A female connector portion 34 is formed on a portion of the holding portion 30 that faces the outside of the outer covering portion 32. The female connector portion 34 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 is the bottom plate portion 11 of the lower shell 10. It is located in the recessed portion 14 provided in the. In this female connector portion 34, a portion of the igniter 40 near the lower end of the terminal pin 42 is exposed. A male connector is inserted into the female connector portion 34, and thereby electrical connection between the core wire of the harness and the terminal pin 42 is realized.

  Further, the above-described injection molding may be performed using the lower shell 10 in which the adhesive layer is provided in advance at a predetermined position on the surface of the bottom plate portion 11 to be covered by the holding portion 30. The adhesive layer can be formed by previously applying an adhesive to a predetermined position on the bottom plate portion 11 and curing the adhesive.

  By doing so, the cured adhesive layer is located between the bottom plate portion 11 and the holding portion 30, so that the holding portion 30 made of the resin molding portion can be more firmly fixed to the bottom plate portion 11. It will be possible. Therefore, if the adhesive layer is provided in a ring shape along the circumferential direction so as to surround the opening 15 provided in the bottom plate portion 11, it becomes possible to secure a higher sealing property in the portion.

  Here, as the adhesive to be applied to the bottom plate portion 11 in advance, one containing as a raw material a resin material having excellent heat resistance, durability, corrosion resistance and the like after curing is preferably used, and for example, a cyanoacrylate-based adhesive. A material containing a resin or a silicone resin as a raw material is particularly preferably used. In addition to the above resin materials, a phenol resin, an epoxy resin, a melamine resin, a urea resin, a polyester resin, an alkyd resin, a polyurethane resin, a polyimide resin, a polyethylene resin, a 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 resin, Arylate resins, polyether ether ketone resin, polyamide-imide resin, liquid crystal polymer, styrene rubber, those containing olefin rubbers such as is available as an adhesive as described above.

  In addition, here, the configuration example in which the igniter 40 can be fixed to the lower shell 10 by injection-molding the holding portion 30 formed of the resin molding portion has been illustrated, but the igniter 40 for the lower shell 10 is illustrated. It is also possible to use other alternative means for fixing the.

  A cup-shaped member 50 is attached to the bottom plate portion 11 so as to cover the protruding cylindrical portion 13, the holding portion 30, and the igniter 40. The cup-shaped member 50 has a bottomed substantially cylindrical shape with an open end on the bottom plate 11 side, and includes a transfer chamber 55 in which a transfer charge 56 is housed. The cup-shaped member 50 projects toward the inside of the combustion chamber 60 in which the gas generating agent 61 is housed so that the flame transfer chamber 55 provided therein faces the ignition portion 41 of the igniter 40. It is arranged to be located.

  The cup-shaped member 50 includes a top wall portion 51 and a side wall portion 52 that define the above-described flame transfer chamber 55, and an extending portion 53 that extends radially outward from a portion of the side wall portion 52 on the open end side. have. The extending portion 53 is formed so as to extend along the inner surface of the bottom plate portion 11 of the lower shell 10. Specifically, the extending portion 53 has a shape bent along the shape of the inner bottom surface of the bottom plate portion 11 in the portion where the protruding cylindrical portion 13 is provided and in the vicinity thereof, and its diameter A tip portion 54 extending in a flange shape is included in a portion on the outer side in the direction.

  The tip portion 54 of the extending portion 53 is arranged between the bottom plate portion 11 and the lower side support member 70 along the axial direction of the housing, whereby the bottom plate portion 11 and the lower side portion are arranged along the axial direction of the housing. It is sandwiched by the support member 70. Here, the lower side support member 70 is in a state of being pressed toward the bottom plate portion 11 side by the gas generating agent 61, the cushion material 85, the upper side support member 80, and the top plate portion 21 arranged above the lower side support member 70. The cup-shaped member 50 is fixed to the bottom plate portion 11 in a state in which the tip end portion 54 of the extending portion 53 is pressed toward the bottom plate portion 11 side by the lower side support member 70. As a result, the cup-shaped member 50 is prevented from falling off the bottom plate portion 11 without using caulking fixation or press-fitting fixation for fixing the cup-shaped member 50.

  The cup-shaped member 50 does not have an opening in either the top wall portion 51 or the side wall portion 52, and surrounds the flame transfer chamber 55 provided therein. When the transfer charge 56 is ignited by the operation of the igniter 40, the cup-shaped member 50 bursts or melts due to the increase in pressure in the transfer chamber 55 and the conduction of generated heat. A material having a relatively low mechanical strength is used.

  Therefore, as the cup-shaped member 50, a metal member such as aluminum or an 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) is used. 66, etc.), a resin member such as a thermoplastic resin represented by polypropylene sulfide resin, polypropylene oxide resin, or the like is preferably used.

  In addition to the above, the cup-shaped member 50 is made of a metal member having high mechanical strength typified by iron, copper, etc., and has an opening in its side wall portion 52. It is also possible to use the one in which a sealing tape is attached so as to close the opening. Further, the fixing method of the cup-shaped member 50 is not limited to the fixing method using the lower side supporting member 70 described above, and another fixing method may be used.

The transfer charge 56 filled in the transfer chamber 55 is ignited by the flame generated by the operation of the igniter 40, and burns to generate hot particles. The transfer charge 56 needs to be one that can reliably start the combustion of the gas generant 61, and generally has a composition of a metal powder / oxidizer represented by B / KNO ₃ or the like. Things etc. are used. As the transfer charge 56, a powdery one, a one molded into a predetermined shape with a binder, or the like is used. As the shape of the transfer charge 56 formed by the binder, there are various shapes such as a granular shape, a cylindrical shape, a sheet shape, a spherical shape, a single-hole cylinder shape, a perforated cylinder shape, and a tablet shape.

  A combustion chamber 60 accommodating the gas generating agent 61 is located in a space surrounding a portion where the cup-shaped member 50 is arranged in the space inside the housing. Specifically, as described above, the cup-shaped member 50 is arranged so as to project into the combustion chamber 60 formed inside the housing, and faces the outer surface of the side wall portion 52 of the cup-shaped member 50. The space provided in the portion and the space provided in the portion facing the outer surface of the top wall portion 51 are configured as the combustion chamber 60.

  A filter 90 is arranged along the inner circumference of the housing in a space surrounding the combustion chamber 60 accommodating the gas generating agent 61 in the radial direction of the housing. The filter 90 has a cylindrical shape and is arranged such that its central axis substantially coincides with the axial direction of the housing.

  The gas generating agent 61 is a chemical agent that is ignited by the heat particles generated by the operation of the igniter 40 and burns to generate gas. As the gas generating agent 61, it is preferable to use a non-azide type 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. Examples of the oxidizing agent include 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 cations is used. As the nitrate, for example, sodium nitrate, potassium nitrate and the like are preferably used. Further, examples of the additive include a binder, a slag forming agent, a combustion modifier, and the like. 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 hydrotalcite or acid clay can be preferably used. As the slag forming agent, silicon nitride, silica, acid clay and the like can be preferably used. Further, as the combustion modifier, metal oxide, ferrosilicon, activated carbon, graphite and the like can be preferably used.

  The shape of the molded body of the gas generating agent 61 includes various shapes such as a granular shape, a pellet shape, a cylindrical shape or the like, and a disk shape. Further, as the columnar one, a perforated (for example, single-hole tubular or perforated tubular) molded article having a through hole inside the molded article is also used. It is preferable that these shapes are appropriately selected according to the specifications of the airbag device in which the disk-type gas generator 1A is incorporated. For example, the shape in which the gas generation rate changes with time when the gas generating agent 61 is burned. It is preferable to select the optimum shape according to the specifications, such as selecting. Further, 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 burning rate, the pressure index, etc. of the gas generating agent 61.

  The filter 90 is, for example, one obtained by winding and sintering a metal wire rod made of stainless steel, steel, or the like, one obtained by pressing and solidifying a net material in which a metal wire rod is braided, or a perforated metal plate wound. Things are used. Here, as the net material, specifically, a knitted wire net, a plain weave wire net, a crimp weave metal wire rod assembly, or the like is used. Further, as the perforated metal plate, for example, an expanded metal in which the metal plate is cut in a zigzag pattern and is expanded to form holes to form a mesh shape, or when the metal plate is perforated with holes. A hook metal or the like that flattens the burrs generated by crushing the burr generated at the periphery of the hole is used. In this case, the size and shape of the holes to be formed can be appropriately changed as needed, and holes of different sizes and shapes may be included on the same metal plate. As the metal plate, for example, a steel plate (mild steel) or a stainless steel plate can be preferably used, and a non-ferrous metal plate such as aluminum, copper, titanium, nickel or an alloy thereof can also be used.

  When the gas generated in the combustion chamber 60 passes through the filter 90, the filter 90 functions as a cooling unit that cools the gas by removing the high temperature heat of the gas, and the 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 released to the outside, it is necessary to ensure that the gas generated in the combustion chamber 60 passes through the filter 90. In the filter 90, a gap 25 having a predetermined size is formed between the peripheral wall portion 22 of the upper shell 20 and the peripheral wall portion 12 of the lower shell 10 which form the peripheral wall portion of the housing. In addition, it is arranged apart from the peripheral wall portions 12 and 22.

  As shown in FIGS. 1 and 2, a plurality of gas ejection openings 23 are provided in the peripheral wall portion 22 of the upper shell 20 in the portion facing the filter 90. The plurality of gas outlets 23 are for discharging the gas passing through the filter 90 to the outside of the housing.

  Further, as shown in FIG. 2, a metal seal tape 24 as a seal member is attached to the inner peripheral surface of the peripheral wall portion 22 of the upper shell 20 so as to close the plurality of gas ejection ports 23. Has been. As the seal tape 24, an aluminum foil or the like having an adhesive member coated on one surface can be preferably used, and the seal tape 24 ensures the airtightness of the combustion chamber 60. In addition, in the present embodiment, the seal member is composed of one strip-shaped seal tape 24.

  Here, as shown in FIG. 1, in the disk-type gas generator 1A according to the present embodiment, the plurality of gas ejection ports 23 have three types of gas ejection ports having different shapes (that is, a plurality of gas ejection ports 23). It includes a first gas outlet 23a, a plurality of second gas outlets 23b and a plurality of third gas outlets 23c). These three kinds of gas ejection ports are opened stepwise as the pressure of the above-mentioned accommodating space, which is the space inside the housing due to the combustion of the gas generant 61, rises during operation of the disk-type gas generator 1A. Accordingly, the opening pressures are different from each other.

  Although the filter 90 and the gap 25 are located between the combustion chamber 60 and the plurality of gas ejection ports 23 as described above, since the flow resistance of the filter 90 to gas is relatively small, The pressure of the accommodation space is substantially equal to the internal pressure of the combustion chamber 60. Therefore, in the following description, this may be referred to as the internal pressure of the combustion chamber 60 instead of the pressure of the accommodation space.

  The first gas ejection port 23a, the second gas ejection port 23b, and the third gas ejection port 23c described above are configured so that their opening pressures are different from each other due to the different opening shapes. As described above, by having a plurality of types of gas ejection ports 23 having different opening pressures, it is possible to prevent a large decrease in the internal pressure rise of the combustion chamber 60 during operation, especially in a low temperature environment, and is intended. Although it becomes possible to obtain the combustion characteristics, the details and the more detailed configuration of the plurality of types of gas ejection ports 23 will be described later.

  Referring again to FIG. 2, in the combustion chamber 60, a lower side support member 70 is arranged near the end located on the bottom plate 11 side. The lower side support member 70 has an annular shape, and is arranged so as to substantially cover the boundary portion between the filter 90 and the bottom plate portion 11 so as to cover the boundary portion between the filter 90 and the bottom plate portion 11. There is. As a result, the lower support member 70 is located between the bottom plate portion 11 and the gas generating agent 61 near the end of the combustion chamber 60.

  The lower support member 70 is provided with an abutting portion 72 that is erected so as to abut the inner peripheral surface of the axial end portion of the filter 90 located on the bottom plate portion 11 side, and radially inward from the abutting portion 72. It has the bottom part 71 extended toward. The bottom portion 71 is formed so as to extend along the inner bottom surface of the bottom plate portion 11 of the lower shell 10. Specifically, the bottom portion 71 has a shape that is bent so as to follow the shape of the inner bottom surface of the bottom plate portion 11 including the portion where the protruding tubular portion 13 is provided, and the bottom portion 71 has a radially inner portion. It includes an upright end portion 73.

  During operation of the lower support member 70, the gas generated in the combustion chamber 60 flows out of the gap between the lower end of the filter 90 and the bottom plate portion 11 without passing through the inside of the filter 90. It functions as an outflow prevention means for preventing The lower support member 70 is formed by pressing a metal plate member, for example, and is preferably a steel plate such as ordinary steel or special steel (for example, a cold rolled steel plate or a stainless steel plate). ).

  Here, the tip end portion 54 of the extending portion 53 of the cup-shaped member 50 described above is disposed between the bottom plate portion 11 and the bottom portion 71 of the lower side support member 70 along the axial direction of the housing, whereby It is sandwiched and held by the bottom plate portion 11 and the bottom portion 71 along the axial direction of the housing. As a result, the cup-shaped member 50 is in a state in which the distal end portion 54 of the extended portion 53 is pressed toward the bottom plate portion 11 side by the bottom portion 71 of the lower side support member 70, and is fixed to the bottom plate portion 11. It will be.

  An upper support member 80 is arranged at an end portion of the combustion chamber 60 located on the top plate 21 side. The upper side support member 80 has a substantially disc shape, and is arranged so as to cover the boundary between the filter 90 and the top plate portion 21 while being directed to the filter 90 and the top plate portion 21. ing. As a result, the upper support member 80 is located between the top plate portion 21 and the gas generating agent 61 near the end of the combustion chamber 60.

  The upper-side support member 80 has a bottom portion 81 that comes into contact with the top plate portion 21 and a contact portion 82 that is provided upright from the peripheral edge of the bottom portion 81. The contact portion 82 is in contact with the inner peripheral surface of the axial end portion of the filter 90 located on the top plate portion 21 side.

  During operation of the upper support member 80, the gas generated in the combustion chamber 60 flows out from the gap between the upper end of the filter 90 and the top plate portion 21 without passing through the inside of the filter 90. It functions as an outflow prevention means to prevent this. Similar to the lower support member 70, the upper support member 80 is formed by pressing a metal plate member, for example, and is preferably a steel plate such as ordinary steel or special steel (for example, steel plate). , Cold-rolled steel plate, stainless steel plate, etc.).

  Inside the upper side support member 80, an annular cushion material 85 is arranged so as to come into contact with the gas generating agent 61 contained in the combustion chamber 60. As a result, the cushion material 85 is located between the top plate portion 21 and the gas generating agent 61 in the portion of the combustion chamber 60 on the top plate portion 21 side, and the gas generating agent 61 is directed toward the bottom plate portion 11 side. Are pressing. The cushion material 85 is provided for the purpose of preventing the gas generating agent 61 formed of a molded body from being crushed by vibration or the like, and is preferably a ceramic fiber molded body, rock wool, or foam resin (for example, Silicone foam, polypropylene foam, polyethylene foam, etc.), chloroprene and rubber such as EPDM.

  Next, with reference to FIG. 2, the operation of the disk-type gas generator 1A in the present embodiment described above will be described.

  When a vehicle equipped with the disk-type gas generator 1A according to the present embodiment collides, the collision is detected by a collision detection unit separately provided in the vehicle, and based on this, a control unit separately provided in the vehicle. The igniter 40 is activated by the energization from. The transfer charge 56 contained in the transfer chamber 55 is ignited and burned by the flame generated by the operation of the igniter 40, and a large amount of heat particles are generated. Due to the combustion of the transfer charge 56, the cup-shaped member 50 bursts or melts, and the above-mentioned hot particles flow into the combustion chamber 60.

  The gas particles 61 housed in the combustion chamber 60 are 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 90, at which time the heat is taken by the filter 90 to be cooled, and the slag contained in the gas is removed by the filter 90 and the gap 25 is formed. Flow into.

  As the pressure in the space inside the housing rises, the seal tape 24 that closes the gas ejection port 23 provided in the upper shell 20 is torn open, and the gas is ejected to the outside of the housing through the gas ejection port 23. Erupted. At that time, the plurality of gas ejection ports 23 are opened in stages, and the ejected gas is introduced into the inside of an airbag provided adjacent to the disc-type gas generator 1A, Inflate and deploy the airbag.

  3 is a cross-sectional view of the upper shell and the sealing tape taken along the line III-III shown in FIGS. 1 and 2, and FIG. 4 is the first to third gas jet ports shown in FIGS. 1 and 3. FIG. Hereinafter, with reference to FIGS. 3 and 4 and FIG. 1 described above, a more detailed configuration of the first to third gas ejection ports 23a to 23c provided in the peripheral wall portion 22 of the upper shell 20 will be described.

  As shown in FIG. 1 and FIG. 3, in the present embodiment, the above-described first gas ejection port 23a, second gas ejection port 23b, and third gas ejection port 23c are provided on the peripheral wall portion 22 of the upper shell 20. They are arranged in a line along the circumferential direction according to a predetermined rule. More specifically, the total number of the plurality of gas ejection ports 23 is 24, and the gas ejection ports 23 are evenly arranged at intervals of 15 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

The number of the first gas ejection ports 23a is four, and the first gas ejection ports 23a are arranged every 90 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. The number of the second gas ejection ports 23b is eight, and is 30 [°], 60 [°], 30 [°], 60 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. It is arranged for each. The number of the third gas outlets 23c is 12, and the third gas outlets 23c are arranged at intervals of 30 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  Here, the 1st gas outlet 23a, the 2nd gas outlet 23b, and the 3rd gas outlet 23c are the 1st gas outlet 23a and the 3rd gas along the circumferential direction of the peripheral wall part 22 of the upper side shell 20. The ejection port 23c, the second gas ejection port 23b, the third gas ejection port 23c, the second gas ejection port 23b, and the third gas ejection port 23c are arranged in this order so that four sets are repeated. As a result, the plurality of gas ejection ports 23 are arranged so as not to overlap each other in the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  As shown in FIG. 1 and FIG. 4 (A), the first gas ejection port 23a has an elongated hole shape having different opening widths in the directions orthogonal to each other, and more specifically, the peripheral wall of the upper shell 20. The opening width L1 along the axial direction of the portion 22 (hereinafter, the opening width L1 along the axial direction of the peripheral wall portion 22 is also referred to as the length L1) is equal to the opening width W1 along the circumferential direction of the peripheral wall portion 22. (Hereinafter, the opening width W1 along the circumferential direction of the peripheral wall portion 22 is also simply referred to as width W1) and has a vertically elongated hole shape. Strictly speaking, the first gas ejection port 23a is composed of a track hole having a pair of opening edge portions extending in parallel along the axial direction of the peripheral wall portion 22.

  As shown in FIG. 1 and FIG. 4 (B), the second gas ejection port 23b has a long hole shape having different opening widths in the directions orthogonal to each other, and more specifically, the peripheral wall of the upper shell 20. The opening width L2 along the axial direction of the portion 22 (hereinafter, the opening width L2 along the axial direction of the peripheral wall portion 22 is also referred to as the length L2) is equal to the opening width W2 along the circumferential direction of the peripheral wall portion 22. (Hereinafter, the opening width W2 along the circumferential direction of the peripheral wall portion 22 is also simply referred to as width W2) and has a vertically long hole shape. Strictly speaking, the second gas ejection port 23b is composed of a track hole having a pair of opening edge portions extending in parallel along the axial direction of the peripheral wall portion 22.

  As shown in FIG. 1 and FIG. 4 (C), the third gas ejection port 23c has a long hole shape having different opening widths in the directions orthogonal to each other, and more specifically, the peripheral wall of the upper shell 20. The opening width L3 along the axial direction of the portion 22 (hereinafter, the opening width L3 along the axial direction of the peripheral wall portion 22 is also referred to as the length L3) is equal to the opening width W3 along the circumferential direction of the peripheral wall portion 22. (Hereinafter, the opening width W3 along the circumferential direction of the peripheral wall portion 22 is also simply referred to as width W3) and has a vertically elongated hole shape. Strictly speaking, the third gas ejection port 23c is composed of a track hole having a pair of opening edge portions extending in parallel along the axial direction of the peripheral wall portion 22.

  That is, each of the first gas ejection port 23a, the second gas ejection port 23b, and the third gas ejection port 23c has a vertically elongated hole shape, whereby all the gas ejection ports 23 have vertically elongated hole shapes. Will be.

  Referring to FIGS. 4 (A) to 4 (C), the opening area (corresponding to the first opening area) of each of the first gas outlets 23a is S1, and one of the second gas outlets 23b is one. If the opening area per unit (corresponding to the second opening area) is S2 and the opening area per unit of the third gas outlet 23c (corresponding to the third opening area) is S3, these S1 to S3 are S1> The condition of S2> S3 is satisfied. That is, the opening area S2 of the second gas outlet 23b is smaller than the opening area S1 of the first gas outlet 23a, and the opening area S3 of the third gas outlet 23c is the opening area S2 of the second gas outlet 23b. Smaller than.

  With reference to FIG. 3, the seal tape 24 is attached to the inner peripheral surface of the upper shell 20 as described above, and each of the 24 gas ejection ports 23 in total is formed by the seal tape 24. It is closed. Here, the sealing tape 24 is attached so that one end 24a and the other end 24b thereof in the extending direction are substantially butted to each other, and each of the 24 gas ejection ports 23 in total is this one sheet. Will be covered by the sealing tape 24 of FIG.

  Here, the shear strength (tensile strength) of the seal tape 24 is F, the thickness of the seal tape 24 at the portion that closes the gas ejection port 23 is t, and the perimeter of the gas ejection port is C (perimeter shown in FIG. 4). When C1 to C3 correspond to the perimeter C) and the opening area of the gas ejection port 23 is S (the above-described opening areas S1 to S3 correspond to the opening area S), the gas ejection is performed. The outlet opening pressure is represented by F × t × C / S.

  Therefore, by appropriately adjusting the circumferential lengths C1 to C3 and the opening areas S1 to S3 described above, in the present embodiment, the opening pressure of the first gas jet port 23a is the lowest and the second gas jet port 23b is the lowest. Has the second lowest opening pressure and the highest opening pressure of the third gas ejection port 23c.

  When the opening pressure is set, as will be understood from the above formula, the opening pressure can be increased by setting the circumferential length C long even when the opening area S is the same. In other words, as in the present embodiment, by configuring each of the plurality of gas ejection ports 23 to have the shape of a vertically elongated hole, it is possible to prevent the adjoining gas ejections from decreasing in order to suppress the pressure resistance of the housing. It is possible to set various opening pressures while ensuring a sufficient space between the outlets 23, and simply increase the size of a plurality of gas ejection ports in a similar shape while keeping a part of the plurality of gas ejection ports in a circular shape. Compared to the case where the opening pressure of a plurality of gas ejection ports is set in stages while increasing the total opening area of the ejection ports, the degree of freedom in design is greatly increased, and as a result, the disc-type gas generator 1A is downsized. Will be possible.

  Here, when the filter 90 is formed by winding and sintering a metal wire rod such as the above-mentioned stainless steel or iron steel, or by pressing a net material in which a metal wire rod is braided and press-hardened, During operation, the pressure of the gas ejected from the gas ejection port 23 causes deformation of the filter 90 in the portion facing the gas ejection port 23, and the deformed portion is pushed outward, and as a result, this is the gas. A phenomenon may occur in which the spout 23 bulges outward.

  This phenomenon is likely to occur when the shape of the gas ejection port 23 is a circular shape, and is less likely to occur when it is a non-circular shape. This is because when the gas outlet 23 has a non-circular shape, the flow resistance to the gas increases at the corners and corners of the gas outlet 23 having the shape, and the opening area of the gas outlet 23 becomes smaller. In comparison, the flow rate of the gas actually flowing is suppressed to be low as a whole, and it is presumed that the force for pushing the filter 90 toward the outside is reduced.

  Based on this viewpoint, it is preferable that the shape of the gas ejection port 23 is a non-circular shape represented by the above-described vertically elongated hole shape, and particularly if the opening area is large in order to set the opening pressure low. It is preferable that the obtained one has a non-round shape. The non-circular shape referred to here includes various shapes, and in addition to the above-described vertically elongated hole shape, a horizontally elongated hole shape, an oblique elongated hole shape, and the like are further mentioned, and further, a cross shape, a V shape. , T-shape, and a shape obtained by rotating these around the center.

When this is quantified and shown, at least one of the plurality of first gas jets 23a, the plurality of second gas jets 23b, and the plurality of third gas jets 23c is one. When the opening area of the gas outlet of S is set to S [mm ² ] and the circumferential length of the one gas outlet is set to C [mm], these S and C are S / C ≦ 0.27 × S preferably it is configured by gas ports of satisfying the shape of ^0.5, more it would be further preferable to satisfy the condition of ^{S / C ≦ 0.22 × S 0.5} .

  FIG. 5 is a diagram schematically showing how the gas outlets are opened stepwise when the gas generator according to the present embodiment is in operation. Hereinafter, with reference to FIG. 5, the reason why the disc-shaped gas generator 1A according to the present embodiment can be prevented from generating a large drop in internal pressure rise during operation, particularly in a low temperature environment, will be described. 5 (A), FIG. 5 (B) and FIG. 5 (C) each schematically show the state at the time when a predetermined time has elapsed from the start of operation. The elapsed time becomes longer in the order of FIG. 5 (B) and FIG. 5 (C).

  When the disk-type gas generator 1A in the present embodiment operates, the gas generating agent 61 starts burning, and the internal pressure of the combustion chamber 60 starts to rise accordingly. In the disc-type gas generator 1A according to the present embodiment, the plurality of gas ejection ports 23 are opened stepwise in the process of increasing the internal pressure of the combustion chamber 60.

  In the first stage after the start of operation, the internal pressure of the combustion chamber 60 reaches a pressure at which any of the first gas outlet 23a, the second gas outlet 23b, and the third gas outlet 23c can be opened. However, the first gas outlet 23a, the second gas outlet 23b, and the third gas outlet 23c are not opened, and the internal pressure continues to rise.

  In the second stage after the start of the operation, the internal pressure of the combustion chamber 60 has the lowest opening pressure among the first gas ejection port 23a, the second gas ejection port 23b, and the third gas ejection port 23c. The internal pressure P1 at which the first gas ejection port 23a can be opened is reached, and along with this, as shown in FIG. 5 (A), the seal tape 24 in the portion covering the four first gas ejection ports 23a is torn open. Gas is ejected through the four opened first gas ejection ports 23a. As a result, the gas output can be obtained within a relatively short time after the start of the operation, and the inflation and deployment of the airbag can be started early.

  Here, in the second stage after the start of the operation, since the second gas ejection port 23b and the third gas ejection port 23c are not yet opened, the internal pressure of the combustion chamber 60 becomes an appropriate high pressure state. As a result, the internal pressure of the combustion chamber 60 does not drop extremely. Therefore, the stable combustion of the gas generating agent 61 is continued, and the inflation and deployment of the airbag can be continued.

  In the third stage after the start of operation, the internal pressure of the combustion chamber 60 is the next lowest after the first gas ejection port 23a among the first gas ejection port 23a, the second gas ejection port 23b and the third gas ejection port 23c. The internal pressure P2 at which the eight second gas outlets 23b having the opening pressure can be opened is reached, and accordingly, as shown in FIG. 5B, the eight second gas outlets 23b are covered. The seal tape 24 of the part is split, and the gas is passed through a total of twelve first gas outlets 23a and second gas outlets 23b that are opened, including the four first gas outlets 23a that are already opened. Is gushed out.

  Here, in the third stage after the start of the operation, since the third gas ejection port 23c is not yet opened, the internal pressure of the combustion chamber 60 is maintained at an appropriate high pressure state, The internal pressure of the combustion chamber 60 does not drop extremely. Therefore, the stable combustion of the gas generating agent 61 is continued, and the inflation and deployment of the airbag can be continued.

  In the fourth stage after the start of operation, the internal pressure of the combustion chamber 60 has the highest opening pressure among the 12th gas outlets of the first gas outlet 23a, the second gas outlet 23b, and the third gas outlet 23c. The internal pressure P3 that can open the 3 gas outlets 23c is reached, and as a result, the seal tape 24 in the portion covering the 12 third gas outlets 23c is cleaved as shown in FIG. 5C. , Including a total of 12 first gas outlets 23a and second gas outlets 23b which have already been opened, a total of 24 first gas outlets 23a, second gas outlets 23b and 23 Gas is ejected through the third gas ejection port 23c.

  Here, at this point in time, the internal pressure of the combustion chamber 60 has already reached a sufficiently high pressure state, so the gas generant 61 continues to burn stably, and all of the gas generant 61 is burned out. As a result, a stable high gas output can be obtained, and the continuous deployment of the airbag can be further continued.

  In the fifth stage after the start of the operation, the gas generating agent 61 is completely burned out to stop the output of the gas, whereby the operation of the disk-type gas generator 1A is ended, and the deployment of the airbag is also ended.

  As described above, in the disc-type gas generator 1A according to the present embodiment, when the disc-type gas generator 1A is operated, the pressure of the above-mentioned accommodation space, which is the space inside the housing due to the combustion of the gas generant 61 Since the plurality of gas outlets 23 are opened stepwise in accordance with the rise, all the gas outlets are opened simultaneously as the pressure in the space inside the housing rises. Compared with the disk-type gas generator configured, it is possible to prevent a large drop in the internal pressure rise, especially in a low temperature environment. Therefore, the gas generating agent 61 can be continuously burned in any temperature environment from a high temperature environment to a low temperature environment, and as a result, the difference in gas output performance due to the environmental temperature can be reduced. Will be possible.

In addition, in order to surely obtain the effect of reducing the difference in gas output performance due to the environmental temperature by setting the plurality of gas outlets 23 to be opened in three stages, it is necessary to set a plurality of gas outlets 23. The sum of the opening areas of the first gas outlets 23a is SA1, the sum of the opening areas of the plurality of second gas outlets 23b is SA2, and the openings of the plurality of third gas outlets 23c. If the sum of the areas is SA3 (SA1 = 4 × S1, SA2 = 8 × S2, SA3 = 12 × S3 in the present embodiment), these SA1 to SA3 satisfy the condition of SA1 <SA2 + SA3. Is preferred. That is, the sum SA1 of the opening areas of each of the plurality of first gas outlets 23a is equal to the sum SA2 of the opening areas of each of the plurality of second gas outlets 23b and each of the plurality of third gas outlets 23c. It is preferable that it is smaller than the total sum of the opening area of the above and the sum SA3. This is because when the sum (SA1) of the opening areas of the plurality of first gas outlets 23a occupies the sum of the opening areas of the plurality of gas outlets 23 (that is, SA1 + SA2 + SA3), the combustion is performed. This is because it becomes difficult to maintain the internal pressure of the chamber 60 at a high pressure.

  Here, referring to FIG. 3, in disk-type gas generator 1A in the present embodiment, the same shape and the same opening area are configured so that they have the same opening pressure. Focusing on the gas outlets that have been created and grasping them as a group of gas outlets according to their formation position, the plurality of gas outlets described above only by the following plurality of gas outlet groups It can be seen that 23 is configured. When determining the gas ejection port group, as described above, the gas ejection port group is determined so that as many gas ejection ports as possible constitute one group of gas ejection ports.

First gas outlet group X: a total of four gas outlets 23a arranged at 90 [°] intervals
Second gas jet group Y1: four gas jets 23b arranged at 90 [°] intervals
Second gas outlet group Y2: four gas outlets 23b arranged at 90 [°] intervals
Third gas outlet group Z: a total of 12 gas outlets 23c arranged at intervals of 30 [°]

  That is, in the disk-type gas generator 1A of the present embodiment, the plurality of gas ejection ports 23 have rotational symmetry with an angle of 120 [°] or less about the axis of the peripheral wall portion 22 of the upper shell 20. As shown, only a total of four gas ejection port groups X, Y1, Y2, and Z, each including a plurality of gas ejection ports having the same opening pressure, which are evenly arranged along the circumferential direction of the peripheral wall portion 22. It is composed of.

  With such a configuration, by any chance, the fixing force of the fixing member (for example, the retainer of the airbag device) for fixing the disk-type gas generator 1A is insufficient only at some positions in the circumferential direction of the housing (for example, deterioration over time). It is possible to prevent the balance of the thrust applied to the disk-type gas generator 1A from being greatly disturbed even when the fixing force is reduced due to the above).

  More specifically, in the second stage after the start of the operation described above, a state in which the four first gas ejection ports 23a that are evenly arranged along the circumferential direction of the circumferential wall portion 22 of the upper shell 20 are opened Therefore, the gas is ejected at four positions at equal intervals along the circumferential direction of the peripheral wall portion 22, and by any chance, the fixing force of the fixing member for fixing the disk-type gas generator 1A is the housing. Even when it is insufficient at only some positions in the circumferential direction, the balance of the thrust applied to the disk-type gas generator 1A becomes relatively undisturbed.

  In addition, in the third stage after the start of the operation described above, a total of twelve first gas outlets 23a and second gas outlets 23a are evenly arranged along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. Since 23b is in an open state, gas is ejected at 12 positions at equal intervals along the circumferential direction of the peripheral wall portion 22, and in the unlikely event that the disc-shaped gas generator 1A is fixed. Even when the fixing force of the members is insufficient at only some positions in the circumferential direction of the housing, the balance of the thrust applied to the disk-type gas generator 1A is not likely to be significantly destroyed.

Therefore, by adopting the above configuration, as compared with the conventional disk-type gas generator can be a safety is more enhanced disk-type gas generator, particularly in the early stages after the start of operation.

  In addition, in the second stage and the third stage after the start of the operation described above, the airbag is not yet fully deployed, so that the distance between the opened gas ejection port 23 and the airbag is Although it is in a very close state, even at that time, the gas is dispersed at the four positions and the twelve positions at equal intervals along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. Since the gas is ejected, it is possible to prevent the high-temperature and high-pressure gas from being concentrated on a local portion of the airbag. Therefore, by adopting the above configuration, it is possible to reduce the possibility of damaging the airbag.

  This is because all the gas outlets other than the gas outlets 23c included in the third gas outlet group Z among the plurality of gas outlets 23 (that is, the first gas outlet 23a and the second gas outlet 23a). All of the ejection ports 23b) are evenly arranged along the circumferential direction of the circumferential wall portion 22 of the upper shell 20. In addition, in the disk-type gas generator 1A in the present embodiment, all of the plurality of gas ejection ports 23 (that is, the third gas ejection port 23c is provided in the first gas ejection port 23a and the second gas ejection port 23b). All of the additions) are evenly arranged along the circumferential direction of the peripheral wall portion 22 of the upper shell 20, so that the peripheral wall portion 22 of the upper shell 20 also has the peripheral wall portion 22 even in the fourth stage after the start of operation described above. The gas is also dispersed and ejected at 24 positions at equal intervals along the direction.

  Further, by adopting the above-mentioned configuration, it is possible to reduce the opening area of each of the plurality of gas ejection ports 23 provided in the housing to be small and increase the number thereof, as compared with the conventional disc-type gas generator. Therefore, the pressure of the space inside the housing at the time of operation can be lowered to a considerable extent within a range in which the gas generating agent 61 can stably and continuously burn. Therefore, it is possible to reduce the thickness of the housing while ensuring the pressure resistance of the housing, and as a result, it is possible to realize a drastic reduction in size and weight of the disk type gas generator.

  As described above, by using the disc-type gas generator 1A according to the present embodiment, it is possible to reduce the size and weight and reduce the difference in gas output performance due to the environmental temperature. The disk-type gas generator has improved safety during operation and reduced damage to the airbag.

  The disk-type gas generator 1A of the present embodiment is of a type that inflates and deploys a standard size airbag, and the outer diameter of the peripheral wall portion 22 of the upper shell 20 is, for example, 60. The peripheral wall portion 22 is designed to have a thickness (plate thickness) of, for example, 1.1 [mm].

  In this case, the length L1 and the width W1 of the first gas ejection port 23a are set to 4.6 [mm] and 1.8 [mm], respectively, and the length L2 and the length L2 of the second gas ejection port 23b are set, respectively. The width W2 is set to, for example, 5.2 [mm] and 1.2 [mm], and the length L3 and the width W3 of the third gas ejection port 23c are, for example, 2.7 [mm] and 1.3, respectively. It is set to [mm].

  Here, the formation of the plurality of gas ejection ports 23 is generally performed by a punching process using a press machine. However, in the case of the above design, the gas ejection ports 23 adjacent to each other are formed. Since the pitch is as small as 7.6 [mm], it is practically impossible to perform this in one punching process due to the restriction of the press machine.

  However, from the viewpoint of reducing the manufacturing cost, it is preferable to form all of the plurality of gas ejection ports 23 by performing the punching process as few times as possible. Therefore, the disk-type gas generator 1A having the above configuration is manufactured. At that time, in the process of forming the plurality of gas ejection ports 23, a total of 12 included in the above-mentioned one set of the first gas ejection port group X and the above-mentioned two sets of the second gas ejection port groups Y1 and Y2. It is possible to form not only one gas ejection port by one punching process but also a total of twelve gas ejection ports included in the above-mentioned one set of third gas ejection port group Z by one punching process. preferable. By doing so, it is possible to form all of the plurality of gas ejection ports 23 by two punching processes, and it is possible to reduce the manufacturing cost.

  In this case, the wall regions R of the peripheral wall portions 22 located between the adjacent gas ejection ports 23 all have approximately the same width along the circumferential direction of the peripheral wall portion 22, and the adjacent gas ejection ports 23 have the same width. The linear distance between the ends of the outlet 23 (the linear distance indicated by the symbol D1 in FIG. 3) is about 6.0 [mm].

  When this distance D1 is less than 7.0 [mm], one end portion 24a and the other end portion 24b in the extending direction of the seal tape 24 are attached to the plurality of wall regions when the seal tape 24 is attached. It becomes difficult to arrange them in abutment with each other on the inner peripheral surface of a specific one of Rs. Here, in the unlikely event that the sticking positions of the both ends of the sealing tape 24 deviate from the wall region R, problems such as deterioration of the sealing performance will occur. In that case, Will require re-pasting work, which will significantly reduce productivity.

  Therefore, it is preferable that any one of the widths of the wall region R is designed to be 7.0 [mm] or more, but the above-described first gas ejection port 23a and second gas ejection port 23b. Also, a specific method for maintaining the shape and size of the third gas ejection port 23c and further preventing the various effects described above from being impaired will be described in a second embodiment described later.

  As in the present embodiment described above, by making the shape of the gas ejection port 23 a long hole shape, the difference in environmental temperature (that is, whether it is in a low temperature environment or a normal temperature environment, or at a high temperature). Depending on the environment), it is possible to make the actual opening area different when the gas outlet 23 is opened, and it is possible to accelerate the combustion of the gas generant especially in a low temperature environment. Become. Therefore, the difference in gas output performance due to the ambient temperature can be remarkably reduced, and a disk-type gas generator with higher performance than the conventional one can be obtained. Hereinafter, this point will be described in detail.

  FIG. 6 is a diagram schematically showing a state in the vicinity of the gas ejection port when the gas generator according to the present embodiment is in operation. Note that FIG. 6A shows a case where the gas generator is operated in a normal temperature environment and a high temperature environment, and FIG. 6B is a case where the gas generator is operated in a low temperature environment. The case is shown.

  As shown in FIG. 6 (A), when the disk-type gas generator 1A according to the present embodiment is operated in a normal temperature environment and a high temperature environment, the gas ejection port 23 increases as the internal pressure of the combustion chamber 60 increases. When the seal tape 24 in the portion that closes is broken, the seal tape 24 is completely broken along the opening edge portion of the gas ejection port 23 having the elongated hole shape, and is broken at the opening edge portion of the gas ejection port 23. The seal tape 24 does not adhere. Therefore, the opening area of the gas ejection port 23 is the same as the actual opening area when the gas ejection port 23 is opened due to the tearing of the seal tape 24.

  On the other hand, as shown in FIG. 6B, when the disc-type gas generator 1A according to the present embodiment is operated in a low temperature environment, the gas ejection port 23 is closed as the internal pressure of the combustion chamber 60 rises. When the seal tape 24 of the portion to be broken is broken along the opening edge portion of the gas ejection port 23 having a long hole shape, the seal tape 24 is completely broken along the entire circumference of the opening edge portion. Rather, breakage does not occur at one of the pair of opening edge portions extending in parallel along the peripheral wall portion 22, and the broken seal tape 24 is attached to the opening edge portion of the gas ejection port 23. Therefore, the actual opening area in the state in which the gas ejection port 23 is opened by the cleavage of the sealing tape 24 is smaller than the opening area of the gas ejection port 23 by the amount corresponding to the cross-sectional area of the sealing tape 24. Will be.

  Therefore, in the normal temperature environment and the high temperature environment, the total sum of the actual opening areas of the gas ejection ports 23 at the time of operation of the disk-type gas generator 1A is secured relatively large, while in the low temperature environment, the disk is The total sum of the actual opening areas of the gas ejection ports 23 during the operation of the mold gas generator 1A is relatively small. As a result, in the low temperature environment, the amount of gas exhausted through the gas ejection port 23 is limited due to the opening of the gas ejection port 23 as compared with the normal temperature environment and the high temperature environment. Therefore, the increase in the internal pressure of the combustion chamber 60 is promoted accordingly. Therefore, it becomes possible to accelerate the combustion of the gas generating agent 61 particularly in a low temperature environment, and it is possible to significantly reduce the difference in gas output performance due to the environmental temperature, and as a result, compared to the conventional case. As a result, a higher performance disc type gas generator can be obtained.

  Here, by adopting the configuration as in this embodiment, there is a difference in whether or not a part of the cleaved seal tape 24 adheres to the opening edge portion of the gas ejection port 23 depending on the ambient temperature. The reason is that the gas ejection port 23 has a non-round hole-like long hole shape, so that the distance from the center of the gas ejection port 23 to the opening edge portion is non-uniform, so that the gas ejection port 23 extends along the opening edge portion. The instantaneous energy required to break the sealing tape 24 at one time increases, and the increase rate of the internal pressure of the combustion chamber 60 is high in a normal temperature environment and a high temperature environment. On the other hand, it is conjectured that the momentary energy cannot be obtained because the rising rate of the internal pressure of the combustion chamber 60 is slow in the low temperature environment.

  In the present embodiment, as a typical example of the long hole shape, the case where the gas ejection port 23 is configured by the track hole has been described as an example, but the opening shape of the gas ejection port 23 is not limited to this. However, the shape may be, for example, an elliptical shape or a rectangular shape. Here, in order to obtain the above-mentioned effect more reliably, it is preferable that the elongated gas ejection port 23 has a pair of opening edge portions extending in parallel along the peripheral wall portion 22. It is more preferable that the holes are formed in the above-mentioned track shape or rectangular shape.

  Further, although the present embodiment has been described by exemplifying a case where all of the plurality of gas ejection ports 23 are configured to have a vertically long hole shape, among the plurality of gas ejection ports 23, Even when only a part of the gas ejection holes 23 is configured to have a vertically long hole shape, a considerable effect can be obtained, and all or some of the plurality of gas ejection ports 23 have a horizontally long hole shape. Even when configured, it is possible to obtain the same effects as the above-mentioned effects. Here, the horizontally elongated hole shape is an elongated hole shape in which the opening width of the peripheral wall portion 22 of the upper shell 20 in the circumferential direction is larger than the opening width of the peripheral wall portion 22 in the axial direction.

  Further, in the present embodiment, the case where the plurality of gas ejection ports 23 are arranged in line along the circumferential direction of the circumferential wall portion 22 of the upper shell 20 has been described as an example. May be arranged in a staggered pattern or over a plurality of rows, or may be arranged in another layout.

  Further, in the present embodiment, description has been given by exemplifying the case where all the gas ejection ports 23 are closed by one strip-shaped sealing tape 24, but, for example, a plurality of gas ejection ports 23 are provided. A plurality of sealing tapes are used so that a part of the outlet 23 is closed by one sealing tape and another part of the plurality of gas ejection ports 23 is closed by another one sealing tape. It may be used.

(Embodiment 2)
FIG. 7 is a front view of a disk-type gas generator according to a second embodiment of the present invention, and FIG. 8 is a cross-sectional view of an upper shell and a sealing tape taken along line VIII-VIII shown in FIG. 7. . Hereinafter, with reference to FIGS. 7 and 8, a disk type gas generator 1B according to the second embodiment of the present invention will be described.

  The disk-type gas generator 1B in the present embodiment is of a type that inflates and deploys a standard-sized airbag, like the disk-type gas generator 1A in the first embodiment described above. 7 and 8, the peripheral wall portion 22 of the upper shell 20 has a first gas ejection port 23a and a second gas ejection port 23a having the same shape and size as those of the disc-type gas generator 1A according to the first embodiment described above. A gas ejection port 23b and a third gas ejection port 23c (see FIG. 4 etc.) are provided.

  In the present embodiment, the first gas ejection port 23a, the second gas ejection port 23b, and the third gas ejection port 23c have a predetermined rule along the circumferential direction of the peripheral wall portion 22 of the upper shell 20 (provided that According to the rules different from the rules shown in the first embodiment), they are arranged in a line. More specifically, the plurality of gas ejection ports 23 has a total number of 24, and is arranged at predetermined angles along the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

The number of the first gas ejection ports 23a is four, and the first gas ejection ports 23a are arranged every 90 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. The number of the second gas ejection ports 23b is eight, and is 30 [°], 60 [°], 30 [°], 60 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. It is arranged for each. The number of the third gas outlets 23c is 12, and the third gas outlets 23c are arranged at intervals of 30 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  Here, the 1st gas outlet 23a, the 2nd gas outlet 23b, and the 3rd gas outlet 23c are the 1st gas outlet 23a and the 3rd gas along the circumferential direction of the peripheral wall part 22 of the upper side shell 20. The ejection port 23c, the second gas ejection port 23b, the third gas ejection port 23c, the second gas ejection port 23b, and the third gas ejection port 23c are arranged in this order so that four sets are repeated. As a result, the plurality of gas ejection ports 23 are arranged so as not to overlap each other in the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  In addition, the above-mentioned 1st gas ejection port 23a, 3rd gas ejection port 23c, 2nd gas ejection port 23b, 3rd gas ejection port 23c, 2nd gas ejection port 23b, 3rd gas ejection port 23c, 1st gas ejection port The intervals between the gas outlets 23 arranged in the order of the outlets 23a, ... Are 21 [°], 9 [°], 21 [°], 9 [°], 21 [ ], 9 [°], and so on.

  Here, with reference to FIG. 8, the disk-shaped gas generator 1B in the present embodiment is configured to have the same shape and the same opening area so as to have the same opening pressure. Focusing on the gas outlets that have been created and grasping them as a group of gas outlets according to their formation position, the plurality of gas outlets described above only by the following plurality of gas outlet groups It can be seen that 23 is configured. When determining the gas ejection port group, as described above, the gas ejection port group is determined so that as many gas ejection ports as possible constitute one group of gas ejection ports.

First gas outlet group X: a total of four gas outlets 23a arranged at 90 [°] intervals
Second gas jet group Y1: four gas jets 23b arranged at 90 [°] intervals
Second gas outlet group Y2: four gas outlets 23b arranged at 90 [°] intervals
Third gas outlet group Z: a total of 12 gas outlets 23c arranged at intervals of 30 [°]

  That is, also in the disk-type gas generator 1B of the present embodiment, as in the case of the above-described first embodiment, the plurality of gas ejection ports 23 are centered on the axis of the peripheral wall portion 22 of the upper shell 20. A total of four sets of a plurality of gas ejection ports having the same opening pressure are evenly arranged along the circumferential direction of the peripheral wall portion 22 so as to have rotational symmetry at an angle of 120 ° or less. It is composed of only the gas ejection port groups X, Y1, Y2 and Z.

Therefore, by setting the disk type gas generator 1B in the present embodiment, conventional compared to disc-type gas generator, the disk-type gas generator enhanced more safety especially in the early stages after the start of operation Can be Therefore, by adopting the above configuration, it is possible to reduce the size and weight, reduce the difference in gas output performance due to environmental temperature, and further improve safety during operation and prevent damage to the airbag. It is possible to make a disk type gas generator whose number is reduced.

  Even in the disc-type gas generator 1B of the present embodiment, all the gas ejection ports 23 except the gas ejection ports 23c included in the third gas ejection port group Z among the plurality of gas ejection ports 23. (That is, all of the first gas outlets 23a and the second gas outlets 23b) are evenly arranged along the circumferential direction of the peripheral wall portion 22 of the upper shell 20, and thus the first gas outlets 23a after the operation is started. In the second step and the third step, the gas is dispersed and ejected at four positions and twelve positions at equal intervals along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. Therefore, by adopting this configuration, the possibility of damaging the airbag can be reduced.

  Here, the disc-type gas generator 1B in the present embodiment is of a type that inflates and deploys a standard-sized airbag as described above, and has an outer diameter of the peripheral wall portion 22 of the upper shell 20. Is designed to be, for example, 60.4 [mm], and the thickness (plate thickness) of the peripheral wall portion 22 is designed to be, for example, 1.1 [mm].

  In this case, the length L1 and the width W1 of the first gas ejection port 23a are set to 4.6 [mm] and 1.8 [mm], respectively, and the length L2 and the length L2 of the second gas ejection port 23b are set, respectively. The width W2 is set to, for example, 5.2 [mm] and 1.2 [mm], and the length L3 and the width W3 of the third gas ejection port 23c are, for example, 2.7 [mm] and 1.3, respectively. It is set to [mm].

  In this case, the wall region R located between the adjacent gas ejection ports 23 of the peripheral wall portion 22 has various widths along the circumferential direction of the peripheral wall portion 22, but the largest width among them. The linear distance between the ends of the pair of gas ejection ports 23 adjacent to the wall region R (the linear distance indicated by the symbol D2 in FIG. 8) is approximately 9.1 [mm].

  As described above, in the disc-type gas generator 1B according to the present embodiment, unlike the disc-type gas generator 1A according to the first embodiment described above, the arrangement intervals of the gas ejection ports 23 are set to the peripheral wall portion of the upper shell 20. By not arranging them completely evenly along the circumferential direction of 22, the wall region R having a straight line distance D2 of 7.0 [mm] or more, which serves as an attachment margin of both ends of the seal tape 24, is formed on the peripheral wall portion. A plurality of the tapes 22 are provided on the tape 22 to facilitate the sticking work of the seal tape 24.

  Therefore, by adopting the configuration, while maintaining the shapes and sizes of the first gas ejection port 23a, the second gas ejection port 23b, and the third gas ejection port 23c shown in the above-described first embodiment, Can achieve the facilitation of the sticking work of the seal tape 24 without impairing the various effects described in the first embodiment.

  Even when this configuration is adopted, a total of 12 gas ejection ports included in one set of the first gas ejection port group X and two sets of the second gas ejection port groups Y1 and Y2 are punched once. In addition to being formed by the processing, a total of 12 gas ejection ports included in one set of the third gas ejection port group Z are formed by one punching process, so that a plurality of gas ejection processes can be performed by a total of two punching processes. It is possible to form all of the individual gas ejection ports 23, and it is possible to realize the minimization of the manufacturing cost in consideration of the constraints of the press machine.

(Embodiment 3)
9 is a sectional view of an upper shell and a sealing tape of a disk type gas generator according to a third embodiment of the present invention, and FIG. 10 is an enlarged view of the first to third gas ejection ports shown in FIG. is there. Hereinafter, a disk type gas generator 1C according to the third embodiment of the present invention will be described with reference to FIGS. 9 and 10.

  The disc-type gas generator 1C according to the present embodiment is different from the disc-type gas generator 1B according to the second embodiment described above in that it is a type that inflates and deploys a small airbag smaller than the standard size. As shown in FIG. 9, the peripheral wall portion 22 of the upper shell 20 is provided with a smaller number of gas ejection ports 23 than in the case of the disc-type gas generator 1B according to the second embodiment described above.

  Specifically, as shown in FIG. 9, the first gas ejection port 23 a, the second gas ejection port 23 b, and the third gas ejection port 23 c are arranged along the circumferential direction of the peripheral wall portion 22 of the upper shell 20 in a predetermined direction. They are arranged in a line in accordance with the rules (however, the rules different from the rules shown in the above-described second embodiment). More specifically, the total number of the plurality of gas ejection ports 23 is 20, and the gas ejection ports 23 are arranged at predetermined angles along the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  The number of the first gas ejection ports 23a is four, and the first gas ejection ports 23a are arranged every 90 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. The number of the second gas outlets 23b is eight, and is 30 [°], 60 [°], 30 [°], 60 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20, It is arranged for each. The number of the third gas outlets 23c is eight, and is 48 [°], 42 [°], 48 [°], 42 [°], along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. It is arranged for each.

  Here, the 1st gas outlet 23a, the 2nd gas outlet 23b, and the 3rd gas outlet 23c are the 1st gas outlet 23a and the 3rd gas along the circumferential direction of the peripheral wall part 22 of the upper side shell 20. The ejection port 23c, the second gas ejection port 23b, the second gas ejection port 23b, and the third gas ejection port 23c are arranged in this order so that four sets are repeated. As a result, the plurality of gas ejection ports 23 are arranged so as not to overlap each other in the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  In addition, the above-mentioned 1st gas ejection port 23a, 3rd gas ejection port 23c, 2nd gas ejection port 23b, 2nd gas ejection port 23b, 3rd gas ejection port 23c, 1st gas ejection port 23a, ... As shown in the drawing, the arrangement intervals between the gas ejection ports 23 arranged in this order are 21 [°], 9 [°], 30 [°], 9 [°], 21 [°], ... Has been done.

  Here, referring to FIG. 9, in disk-type gas generator 1C in the present embodiment, the same shape and the same opening area are configured so that they have the same opening pressure. Focusing on the gas outlets that have been created and grasping them as a group of gas outlets according to their formation position, the plurality of gas outlets described above only by the following plurality of gas outlet groups It can be seen that 23 is configured. When determining the gas ejection port group, as described above, the gas ejection port group is determined so that as many gas ejection ports as possible constitute one group of gas ejection ports.

First gas outlet group X: a total of four gas outlets 23a arranged at 90 [°] intervals
Second gas jet group Y1: four gas jets 23b arranged at 90 [°] intervals
Second gas outlet group Y2: four gas outlets 23b arranged at 90 [°] intervals
Third gas outlet group Z1: a total of four gas outlets 23c arranged at 90 [°] intervals
Third gas outlet group Z2: four gas outlets 23c in total arranged at 90 [°] intervals

  That is, in the disk-type gas generator 1C of the present embodiment, the plurality of gas ejection ports 23 have rotational symmetry with an angle of 120 [°] or less about the axis of the peripheral wall portion 22 of the upper shell 20. A total of five gas ejection port groups X, Y1, Y2, Z1, composed of a plurality of gas ejection ports having the same opening pressure, which are evenly arranged along the circumferential direction of the peripheral wall portion 22 to have. It consists of Z2 only.

Therefore, by setting the disk type gas generator 1C in the present embodiment, conventional compared to disc-type gas generator, the disk-type gas generator enhanced more safety especially in the early stages after the start of operation Can be Therefore, by adopting the above configuration, it is possible to reduce the size and weight, reduce the difference in gas output performance due to environmental temperature, and further improve safety during operation and prevent damage to the airbag. It is possible to make a disk type gas generator whose number is reduced.

Also in the disc-type gas generator 1C of the present embodiment, all the remaining gas out of the plurality of gas outlets 23 except the gas outlets 23c included in the third gas outlet groups Z1 and Z2. Since the ejection ports (that is, all of the first gas ejection port 23a and the second gas ejection port 23b) are evenly arranged along the circumferential direction of the peripheral wall portion 22 of the upper shell 20, after the start of the operation described above. In the second stage and the third stage, the gas is dispersed and ejected at four positions and twelve positions at equal intervals along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. . Therefore, by adopting this configuration, the possibility of damaging the airbag can be reduced.

  Here, as described above, the disc-type gas generator 1C of the present embodiment is of a type that inflates and deploys a small airbag smaller than the standard size, and the peripheral wall portion of the upper shell 20. The outer diameter of 22 is designed to be, for example, 57.5 [mm], and the thickness (plate thickness) of the peripheral wall portion 22 is designed to be, for example, 1.1 [mm].

  In this case, referring to FIG. 10, length L1 and width W1 of first gas ejection port 23a are set to 3.7 [mm] and 2.1 [mm], respectively, and The length L2 and the width W2 of the outlet 23b are both set to 2.0 [mm] (that is, are set to have a circular shape in plan view), and the length L3 and the width W3 of the third gas ejection port 23c are , 2.7 [mm] and 1.3 [mm], respectively.

  In this case, the wall region R located between the adjacent gas ejection ports 23 of the peripheral wall portion 22 has various widths along the circumferential direction of the peripheral wall portion 22, but the largest width among them. The linear distance between the ends of the pair of gas ejection ports 23 adjacent to the wall region R (the linear distance indicated by the symbol D3 in FIG. 9) is approximately 12.4 [mm].

  As described above, in the disc-type gas generator 1C according to the present embodiment, similarly to the disc-type gas generator 1B according to the second embodiment described above, the arrangement intervals of the gas ejection ports 23 are set to the peripheral wall portion of the upper shell 20. 22 are not completely evenly arranged along the circumferential direction, so that the wall area R, which is a margin for pasting both ends of the seal tape 24 and has the linear distance D3 of 7.0 [mm] or more, is formed on the circumferential wall portion. A plurality of the tapes 22 are provided on the tape 22 to facilitate the sticking work of the seal tape 24.

  Even when this configuration is adopted, a total of 12 gas ejection ports included in one set of the first gas ejection port group X and two sets of the second gas ejection port groups Y1 and Y2 are punched once. In addition to being formed by the processing, a total of eight gas outlets included in the two sets of the third gas outlet groups Z1 and Z2 are formed by a single punching process, so that a total of two punching processes can be performed. Therefore, it is possible to form all of the plurality of gas ejection ports 23, and the manufacturing cost can be minimized in consideration of the restrictions of the press machine.

(Embodiment 4)
11 is a cross-sectional view of an upper shell and a sealing tape of a disk type gas generator according to a fourth embodiment of the present invention, and FIG. 12 is an enlarged view of the first to third gas ejection ports shown in FIG. is there. Hereinafter, a disk type gas generator 1D according to the fourth embodiment of the present invention will be described with reference to FIGS. 11 and 12.

  The disc-type gas generator 1D according to the present embodiment is different from the disc-type gas generator 1B according to the above-described second embodiment in that a large airbag larger than a standard size is inflated and deployed. As shown in FIG. 11, the peripheral wall portion 22 of the upper shell 20 is provided with a larger number of gas ejection ports 23 than in the disc-type gas generator 1B of the second embodiment described above.

  Specifically, as shown in FIG. 11, the first gas ejection port 23 a, the second gas ejection port 23 b, and the third gas ejection port 23 c are arranged along the circumferential direction of the peripheral wall portion 22 of the upper shell 20 in a predetermined direction. They are arranged in a line in accordance with the rules (however, the rules different from the rules shown in the above-described second embodiment). More specifically, the plurality of gas ejection ports 23 has a total number of 32, and is arranged at predetermined angles along the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  The number of the first gas outlets 23a is eight, and is 21 [°], 69 [°], 21 [°], 69 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. It is arranged for each. The number of the second gas outlets 23b is eight, and is 30 [°], 60 [°], 30 [°], 60 [°] along the circumferential direction of the peripheral wall portion 22 of the upper shell 20, It is arranged for each. The number of the third gas outlets 23c is 16, and 21 [°], 9 [°], 21 [°], 39 [°] are provided along the circumferential direction of the peripheral wall portion 22 of the upper shell 20. 21 [°], 9 [°], 21 [°], 39 [°], ...

  Here, the first gas ejection port 23a, the second gas ejection port 23b, and the third gas ejection port 23c are arranged along the circumferential direction of the peripheral wall portion 22 of the upper shell 20 along the circumferential direction of the first gas ejection port 23a and the first gas ejection port 23a. The ejection port 23a, the third gas ejection port 23c, the second gas ejection port 23b, the third gas ejection port 23c, the third gas ejection port 23c, the second gas ejection port 23b, and the third gas ejection port 23c are arranged in this order. It is arranged so that four sets are repeated as one set. As a result, the plurality of gas ejection ports 23 are arranged so as not to overlap each other in the circumferential direction of the peripheral wall portion 22 of the upper shell 20.

  In addition, the above-mentioned 1st gas ejection port 23a, 1st gas ejection port 23a, 3rd gas ejection port 23c, 2nd gas ejection port 23b, 3rd gas ejection port 23c, 3rd gas ejection port 23c, 2nd gas ejection port The arrangement intervals between the gas outlets 23 arranged in the order of the outlet 23b, the third gas outlet 23c, the first gas outlet 23a, ... Are 21 [°] and 9 [°] in this order. ], 9 [°], 12 [°], 9 [°], 9 [°], 12 [°], 9 [°], ...

  Here, with reference to FIG. 11, the disk-shaped gas generator 1D in the present embodiment is configured to have the same shape and the same opening area so as to have the same opening pressure. Focusing on the gas outlets that have been created and grasping them as a group of gas outlets according to their formation position, the plurality of gas outlets described above only by the following plurality of gas outlet groups It can be seen that 23 is configured. When determining the gas ejection port group, as described above, the gas ejection port group is determined so that as many gas ejection ports as possible constitute one group of gas ejection ports.

First gas outlet group X1: a total of four gas outlets 23a arranged at 90 [°] intervals
First gas outlet group X2: a total of four gas outlets 23a arranged at 90 [°] intervals
Second gas jet group Y1: four gas jets 23b arranged at 90 [°] intervals
Second gas outlet group Y2: four gas outlets 23b arranged at 90 [°] intervals
Third gas outlet group Z1: a total of four gas outlets 23c arranged at 90 [°] intervals
Third gas outlet group Z2: four gas outlets 23c in total arranged at 90 [°] intervals
Third gas outlet group Z3: a total of four gas outlets 23c arranged at 90 [°] intervals
Third gas outlet group Z4: a total of four gas outlets 23c arranged at 90 [°] intervals

  That is, in the disk-type gas generator 1D of the present embodiment, the plurality of gas ejection ports 23 have rotational symmetry with an angle of 120 [°] or less about the axis of the peripheral wall portion 22 of the upper shell 20. As shown, a total of eight gas ejection port groups X1, X2, Y1, Y2 composed of a plurality of gas ejection ports having the same opening pressure, which are evenly arranged along the circumferential direction of the peripheral wall portion 22. It is composed of only Z1, Z2, Z3 and Z4.

Therefore, by setting the disk type gas generator 1D in the present embodiment, conventional compared to disc-type gas generator, the disk-type gas generator enhanced more safety especially in the early stages after the start of operation Can be Therefore, by adopting the above configuration, it is possible to reduce the size and weight, reduce the difference in gas output performance due to environmental temperature, and further improve safety during operation and prevent damage to the airbag. It is possible to make a disk type gas generator whose number is reduced.

  Here, as described above, the disk-type gas generator 1D of the present embodiment is of a type that inflates and deploys a large airbag larger than the standard size, and the peripheral wall portion of the upper shell 20. The outer diameter of 22 is designed to be 70.0 [mm], and the thickness (plate thickness) of the peripheral wall portion 22 is designed to be 1.3 [mm], for example.

  In this case, referring to FIG. 11, length L1 and width W1 of first gas ejection port 23a are set to, for example, 4.4 [mm] and 1.8 [mm], respectively, and second gas ejection is performed. The length L2 and the width W2 of the outlet 23b are set to, for example, 5.2 [mm] and 1.4 [mm], respectively, and the length L3 and the width W3 of the third gas ejection port 23c are, for example, 2.5 and 2.5, respectively. [Mm] and 1.4 [mm] are set.

  In this case, the wall region R located between the adjacent gas ejection ports 23 of the peripheral wall portion 22 has various widths along the circumferential direction of the peripheral wall portion 22, but the largest width among them. The linear distance between the ends of the pair of gas ejection ports 23 adjacent to the wall region R (the linear distance indicated by the symbol D4 in FIG. 11) is approximately 10.5 [mm].

  As described above, in the disk-type gas generator 1D according to the present embodiment, as in the disk-type gas generator 1B according to the second embodiment described above, the arrangement intervals of the gas ejection ports 23 are set to the peripheral wall portion of the upper shell 20. By not arranging them completely evenly along the circumferential direction of 22, the wall area R, which serves as a bonding margin for both ends of the seal tape 24 and has the linear distance D4 of 7.0 [mm] or more, is formed on the peripheral wall portion. A plurality of the tapes 22 are provided on the tape 22 to facilitate the sticking work of the seal tape 24.

  Even when this configuration is adopted, a total of 12 gas ejection ports included in one set of the first gas ejection port group X1 and the two sets of the third gas ejection port groups Z1 and Z3 are punched once. In addition to forming by processing, a total of 12 gas outlets included in one set of first gas outlet group X2 and two sets of third gas outlet group Z2, Z4 are formed by one punching process. Further, by forming a total of eight gas ejection ports included in the two sets of second gas ejection port groups Y1 and Y2 in one punching process, a plurality of gas ejection ports can be formed in a total of three punching processes. Since it becomes possible to form all of the gas ejection ports 23, the manufacturing cost can be minimized in consideration of the restrictions of the press machine.

  In Embodiments 1 to 4 of the present invention described above, when the number of gas ejection ports included in one gas ejection port group is at least four (that is, in the circumferential direction on the peripheral wall portion of the housing). The number of the gas jets having the same opening pressure and arranged uniformly along the line is set to be 4), but the gas jets included in the one group of gas jets have been described. The number of outlets can be a minimum of three.

As described above, by setting the number of gas ejection ports included in one set of gas ejection ports to be at least three or more, by any chance, the fixing force of the fixing member for fixing the disk-type gas generator is increased in the circumferential direction of the housing. Even if it is insufficient at only some positions in, it is possible to prevent the balance of the thrust applied to the disk-type gas generator from being greatly disturbed compared to the conventional disk-type gas generator, and as a result. , it may be particularly safe and more enhanced disk-type gas generator in the initial stage after the start of operation.

  Therefore, the number for each type of gas outlets disclosed in the first to fourth embodiments of the present invention (that is, the number of each of the first gas outlet, the second gas outlet, and the third gas outlet) is If the number of gas outlets included in one group of gas outlets is at least three (ie, the plurality of gas outlets included in one group of gas outlets is 120 [°]). Any number may be used as long as it satisfies the condition of having rotational symmetry with the following angles).

  Similarly, the shape, size, layout, etc. of each type of gas ejection port disclosed in the first to fourth embodiments of the present invention can be variously modified without departing from the spirit of the present invention. .

  Here, in the above-described first to fourth embodiments of the present invention, a plurality of first gas ejection ports included in one set or two or more first gas ejection port groups, one set or two or more sets. The plurality of second gas outlets included in the second gas outlet group and the plurality of third gas outlets included in one or more sets of the third gas outlet groups are the same. The opening pressure of the gas ejection port is mainly as described above, although the description has been given by exemplifying the case where the opening shape has the same shape and the same opening area. It is determined by the opening area and the circumference.

  Therefore, the method of providing a plurality of gas ejection ports having the same opening pressure is not limited to the method of providing a plurality of gas ejection ports having the same shape and the same opening area as described above. That is, even if the gas ejection ports have different shapes and different opening areas, it is possible to set the same opening pressure by appropriately adjusting the opening area and the peripheral length thereof.

  Further, for example, by appropriately adjusting the circumferential length, the opening pressure of the gas ejection port having a large opening area can be made higher than the opening pressure of the gas ejection port having a small opening area, and vice versa. By appropriately adjusting the area, it is possible to make the opening pressure of the gas outlet having a small circumference longer than the opening pressure of the gas outlet having a large circumference. Therefore, in order to make the opening pressure different depending on the type of the gas ejection port, the opening area and the peripheral length may be appropriately adjusted.

  In this way, the gas ejection ports arranged with a rotational symmetry of 120 [°] or less on the peripheral wall portion of the housing along the circumferential direction may be configured so that their opening pressures are the same, The shape and opening area of each gas ejection port are not particularly limited. In addition, the opening pressure of the gas ejection port can be adjusted as appropriate by changing the shear strength and thickness of the seal member that closes the gas ejection port, so these can be adjusted individually for each gas ejection port. It may be done.

  Note that, as a relatively easy designing method in which a plurality of gas outlets provided in the housing are opened stepwise in three steps, for example, basically only the opening area of the gas outlets is focused on. It is assumed that there is a method of making this different, and a method of making this different by paying attention only to the circumference of the gas ejection port.

  Here, in the disk-type gas generator according to the former method, a plurality of gas outlets provided in the peripheral wall portion of the housing are configured by a plurality of gas outlet groups, and the plurality of gas outlets are provided. The outlet groups have the same first opening area evenly arranged along the circumferential direction of the peripheral wall portion so as to have rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall portion. One or two or more groups of first gas outlets composed of a plurality of first gas outlets, and the peripheral wall having rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall portion. Of one set or two or more sets of second gas ejection ports each having a plurality of second gas ejection ports having the same second opening area, which are evenly arranged along the circumferential direction of the portion, and the peripheral wall portion. An angle of 120 ° or less around the axis One or two or more sets of three gas outlets having the same third opening area, which are evenly arranged along the circumferential direction of the peripheral wall portion so as to have rotational symmetry. And a plurality of gas outlets, the second opening area being smaller than the first opening area, the third opening area being smaller than the second opening area. Are arranged so as not to overlap each other in the circumferential direction of the peripheral wall portion.

  On the other hand, in the disk-type gas generator according to the latter method, a plurality of gas outlets provided in the peripheral wall portion of the housing is configured by a plurality of gas outlet groups, and The outlet groups have the same first perimeter evenly arranged along the circumferential direction of the peripheral wall so as to have rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall. One or two or more groups of first gas outlets composed of a plurality of first gas outlets, and the peripheral wall having rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall portion. Of one or more sets of second gas ejection ports each having a plurality of second gas ejection ports having the same second circumferential length and arranged evenly along the circumferential direction of the portion, and the peripheral wall portion. Rotate with an angle of 120 ° or less around the axis One or two or more sets of third gas jets composed of a plurality of third gas jets having the same third circumferential length that are evenly arranged along the circumferential direction of the circumferential wall portion so as to have symmetry. An outlet group only, the second perimeter is greater than the first perimeter, the third perimeter is greater than the second perimeter, and the plurality of gas outlets are The circumferential wall portions are arranged so as not to overlap each other in the circumferential direction.

  In addition, in the above-described first to fourth embodiments of the present invention, description has been given by exemplifying the case where the present invention is applied to a so-called disk type gas generator, but the application target of the present invention is not limited to this. However, the present invention can be applied to, for example, a cylinder type gas generator.

  The low temperature environment, the normal temperature environment, and the high temperature environment described above refer to an environment in which the environmental temperature is around −40 [° C.], an environment around 20 [° C.], and an environment around 85 [° C.], respectively. I mean.

  As described above, the above-described embodiments disclosed this time are exemplifications in all respects, and are not restrictive. The technical scope of the present invention is defined by the claims, and includes the meaning equivalent to the description of the claims and all modifications within the scope.

  1A-1D Gas generator, 10 Lower shell, 11 Bottom plate part, 12 peripheral wall part, 13 Protruding cylindrical part, 14 Dimple part, 15 Opening part, 20 Upper shell, 21 Top plate part, 22 Peripheral wall part, 23 Gas Jet port, 23a First gas jet port, 23b Second gas jet port, 23c Third gas jet port, 24 Seal tape, 24a One end part, 24b Other end part, 25 Gap part, 30 Holding part, 31 Inner coating part, 32 outer covering part, 33 connecting part, 34 female connector part, 40 igniter, 41 igniting part, 42 terminal pin, 50 cup-shaped member, 51 top wall part, 52 side wall part, 53 extending part, 54 tip part, 55 fire transfer chamber, 56 transfer charge, 60 combustion chamber, 61 gas generating agent, 70 lower support member, 71 bottom part, 72 contact part, 73 tip part, 80 upper support member, 81 bottom part, 82 contact part 85 cushion material, 90 filter, R wall area.

Claims (6)

A housing having a cylindrical peripheral wall portion provided with a plurality of gas ejection ports, and one end portion and the other end portion in the axial direction of the peripheral wall portion are closed;
A gas generating agent disposed in the accommodation space located inside the housing,
An igniter attached to the housing for burning the gas generant;
A seal member for closing the plurality of gas ejection ports,
The plurality of gas outlets is composed of a plurality of sets of gas outlets,
The plurality of gas ejection port groups,
A plurality of first opening pressures having the same first opening pressure are evenly arranged along the circumferential direction of the peripheral wall portion so as to have rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall portion. 1 or 2 or more groups of 1st gas ejection port which consist of 1 gas ejection port,
A plurality of second opening pressures having the same second opening pressure are evenly arranged along the circumferential direction of the peripheral wall portion so as to have rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall portion. One set of two gas outlets or two or more second gas outlet groups,
A plurality of third opening pressures having the same third opening pressure are evenly arranged along the circumferential direction of the peripheral wall portion so as to have rotational symmetry at an angle of 120 [°] or less about the axis of the peripheral wall portion. And only one or two or more sets of third gas outlets consisting of three gas outlets,
The second opening pressure is higher than the first opening pressure,
The third opening pressure is higher than the second opening pressure,
The plurality of gas ejection ports are arranged in a line along the circumferential direction of the peripheral wall portion so as not to overlap each other in the circumferential direction of the peripheral wall portion ,
The sealing member is composed of at least one sealing tape attached to the inner peripheral surface of the peripheral wall portion,
When the plurality of gas outlets are viewed as a whole, the plurality of gas outlets are not evenly arranged along the circumferential direction of the peripheral wall portion, so that the plurality of gas outlets are formed. A maximum width wall region in which the linear distance between the end portions of the gas outlets adjacent to each other in the circumferential direction of the peripheral wall portion is maximum is provided in the peripheral wall portion along the circumferential direction of the peripheral wall portion,
A pair of ends located in the extending direction of the sealing tape is located in any of the plurality of maximum width wall regions,
At least one of the plurality of first gas ejection ports, the plurality of second gas ejection ports, and the plurality of third gas ejection ports is an elongated hole-shaped gas ejection port,
When operating in a low temperature environment where the ambient temperature is −40 [° C.], when the seal member at the portion that closes the plurality of elongated hole-shaped gas ejection ports is cleaved, the plurality of elongated holes At least a part of the sealing member of the portion that closes the gas outlet having a shape does not completely break along the entire circumference of the opening edge portion of the gas outlet having the long hole shape, and after the tearing, A gas generator that is attached to part of the opening edge. The straight line distance in the widest wall region, 7.0 [mm] Ru der above, the gas generator according to claim 1. Each of the plurality of elongated hole-shaped gas ejection ports has an elongated hole shape in which the opening width along the axial direction of the peripheral wall portion is larger than the opening width along the circumferential direction of the peripheral wall portion, The gas generator according to claim 1 or 2 . Of the plurality of gas ejection ports, all the remaining gas ejection ports except the gas ejection ports included in the third gas ejection port group are evenly arranged along the circumferential direction of the peripheral wall portion. The gas generator according to any one of claims 1 to 3 . The sum of the opening areas of the plurality of first gas outlets is the sum of the opening areas of the plurality of second gas outlets and the opening area of each of the plurality of third gas outlets. The gas generator according to any one of claims 1 to 4 , which is smaller than the sum of the sum and the sum. At least one of the plurality of first gas outlets, the plurality of second gas outlets, and the plurality of third gas outlets has an opening area of one gas outlet S [mm ² ] and the circumferential length of the one gas ejection port is C [mm], these S and C have a shape satisfying the condition of S / C ≦ 0.27 × S ^0.5 . The gas generator according to any one of claims 1 to 5 .

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