JP4587783B2 - Unit for driving gas generator and pretensioner - Google Patents

Description

  The present invention relates to a gas generator that generates gas by burning a gas generating agent and a driving unit for a pretensioner device including the gas generator, and in particular, a pair of plates when incorporated in a driving unit for a pretensioner device. The present invention relates to a so-called side-injection type gas generator that is sandwiched and fixed by a member, and a driving unit for a pretensioner device including the same.

  Conventionally, seat belt devices and airbag devices have been widely used from the viewpoint of protecting automobile occupants. Among these, the seat belt device is equipped for the purpose of preventing the occupant from being thrown into or out of the vehicle due to an impact caused by a vehicle collision, and restrains the occupant to the seat by winding the belt around the occupant's body. It is to be fixed.

  In recent years, a seat belt device having a pretensioner function has been rapidly spread to improve an occupant protection function. The pretensioner function is to instantaneously wind up the slack of the seat belt caused by the thickness of clothes or the like at the time of collision or immediately before the collision, thereby enhancing the restraining effect of the occupant. This pretensioner function is realized by the seat belt being strongly pulled in by the gas pressure output from a gas generator called a micro gas generator.

  Various mechanisms are known as drive units for the pretensioner apparatus to which the gas generator is assembled. One of them is a pair of plate-like members wound around an annular metal belt connected to a shaft for retracting the seat belt and closing the hollow portion of the annularly wound metal belt. There is known a drive unit for a pretensioner device having a configuration in which a metal belt is sandwiched by a gas generator and a gas generator is disposed in a working space defined by the metal belt and a pair of plate-like members. No. 2001-213278 (see Patent Document 1)). In this type of pretensioner drive unit, since the working space is located on the side of the gas generator, a so-called side-injection type gas generator in which the direction of gas discharge is lateral is used. .

In the driving unit of the pretensioner device disclosed in Patent Document 1, the pressure in the working space defined by the metal belt and the pair of plate-like members is increased by the gas output from the gas generator, As the metal belt is spread outward, the shaft rotates by a predetermined amount to retract the seat belt.
JP 2001-213278 A

  In the driving unit of the pretensioner device disclosed in Patent Document 1 described above, a hole is provided in advance in the side plate portion of the cup member of the gas generator. Is configured to be introduced into the working space. On the other hand, in the driving unit of the pretensioner device provided with the side-injection type gas generator devised by the present inventors, the outer shell of the gas generator is generated by the gas pressure when the gas generator is operated. A crack is generated in the side surface of the bottomed cylindrical cup member constituting a part of the housing, and the gas is introduced into the working space when the crack grows and the cup member opens. In order to stably obtain a predetermined output in the gas generator having such a configuration, it is necessary that the cup member is reliably opened at a predetermined pressure. For this reason, a thin portion (referred to as a score) is generally formed on the cup member of the gas generator by pressing or the like, and usually the cup member positioned in the gas outlet direction. A score is formed on the surface.

  For example, in the side-injection-type gas generator 1H devised by the present inventors shown in FIG. 11, the side plate portion of the actuating charge cup (AC cup) 40, which is the surface of the housing located in the gas outlet direction. A plurality of scores 49 (usually about 1 to 10 or more) extending in the vertical direction are provided in a substantially central portion of the vertical direction 41 in the vertical direction. Although not shown, normally, in a vertical-spout type gas generator, a plurality of scores extending in the radial direction from the center are provided on the top plate portion of the AC cup.

  As a result, when the gas pressure in the AC cup 40 reaches a predetermined pressure, the AC cup 40 opens from the point where the score 49 of the AC cup 40 is formed, so that gas is supplied to the working space. become. As a result, stable seat belt retraction is realized.

  However, when a score is provided at the substantially central portion of the side plate portion of the side-jet type gas generator, the AC cup is divided into fine broken pieces, and a large number of broken pieces are scattered in the working space. Arise. If broken pieces are scattered in the working space, the broken pieces may be caught between the metal belt and the pair of plate-like members, which affects the seat belt retracting performance. Is concerned. Therefore, in the driving unit of the pretensioner device, it is preferable that the broken pieces of the housing generated when the gas generator is operated are enlarged as much as possible to reduce the number of broken pieces.

  Therefore, the present invention has been made to solve the above-mentioned problems, and it is possible to increase the size of the broken pieces of the cup member that constitutes a part of the housing, which occurs during operation, and the number of broken pieces. It is an object of the present invention to provide a driving unit for a pretensioner device that can stably obtain a desired seat belt retracting performance by providing a gas generator that can suppress the above-mentioned problem.

  A gas generator according to the present invention includes an igniter and a housing, and the housing is sandwiched and fixed from above and below by a pair of plate-like members arranged substantially in parallel. The gas generating agent accommodated in the gas generating agent accommodating chamber formed inside the housing is ignited by the igniter and burns to generate gas. In the gas generator according to the present invention, the housing includes a base member that holds the igniter, and a bottomed cylinder that is attached to the base member and includes a side plate portion and a bottom plate portion that form the gas generating agent storage chamber. Shaped cup member. And the score is provided in the surface of the said cup member so that the boundary part of the said side plate part of the said cup member and the said baseplate part may be included in part.

  In this way, by providing a score on the surface of the cup member so as to partially include the boundary between the side plate portion and the bottom plate portion of the cup member, when the gas generator is operated, the end portion of the score is changed to the side plate portion. Cracks are generated toward the surface, and the generation of cracks in the extending direction of the boundary portion between the fragile side plate portion and the bottom plate portion is suppressed. Therefore, it is possible to increase the size of broken fragments, and as a result, it is possible to reduce the number of broken fragments. In addition, the surface of the cup member referred to here includes an outer surface that is an outer main surface of the bottomed cylindrical cup member and an inner surface that is an inner main surface, and the score is on the outer surface of the cup member. It may be provided or may be provided on the inner surface.

  In the gas generator according to the present invention, it is preferable that the score is provided on the bottom plate portion with the boundary portion as a base end. Moreover, in the gas generator based on the said invention, it is preferable that the said score is provided in the said side-plate part by making the said boundary part into a base end. Further, in the gas generator according to the present invention, it is preferable that the score is provided so as to straddle the boundary portion and reach the bottom plate portion from the side plate portion.

  By configuring in this way, it becomes possible to intentionally direct the direction of crack generation during operation of the gas generator toward the side plate portion and the bottom plate portion, so that a crack is formed at the boundary between the fragile side plate portion and the bottom plate portion. It is possible to suppress the occurrence of the occurrence of the failure, and the enlargement of the broken fragments and the reduction in the number of broken fragments can be realized. In addition, since the score can be formed by pressing simultaneously with the cup-shaped molding, there is no worry that the manufacturing process becomes complicated.

  A driving unit for a pretensioner device according to the present invention includes a pair of plate-like members disposed substantially in parallel so that their main surfaces face each other, and a gas generator sandwiched between the pair of plate-like members, A driving belt-like member which is positioned between the pair of plate-like members and is wound so as to surround the gas generator. The gas generator includes an igniter and a gas generating agent storage chamber in which a gas generating agent that is ignited by the igniter and generates gas by combustion is stored, and the pair of plate-like members includes And a housing fixed by being sandwiched from above and below. In the gas generator assembled to the driving unit of the pretensioner device according to the present invention, the housing is attached to the base member for holding the igniter and the base member, and the gas generating agent storage chamber. And a bottomed cylindrical cup member including a bottom plate portion, and the surface of the cup member has a score so as to partially include a boundary portion between the side plate portion and the bottom plate portion. Is provided.

  As described above, by incorporating a gas generator having a score on the surface of the cup member so as to partially include a boundary portion between the side plate portion and the bottom plate portion of the cup member, the gas is obtained by incorporating the gas generator into the driving unit of the pretensioner device. Since the broken pieces generated during the operation of the generator are enlarged and the number of broken pieces is reduced, the driving unit of the pretensioner device that can stably obtain the desired seat belt retracting performance can be obtained.

  According to the present invention, it is possible to provide a gas generator capable of increasing the size of the broken pieces of the cup member that constitutes a part of the housing that is generated during operation and suppressing the number of broken pieces. it can. Further, by incorporating this gas generator into the drive unit of the pretensioner device, it is possible to provide a drive unit for the pretensioner device in which the desired seat belt retracting performance can be stably obtained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 (A) is a schematic cross-sectional view of a gas generator according to Embodiment 1 of the present invention, and FIG. 1 (B) is a plan view of the gas generator according to Embodiment 1 of the present invention. Here, the schematic cross-sectional view shown in FIG. 1A is a schematic cross-sectional view when the gas generator is cut along the line IA-IA in FIG.

  As shown in FIG. 1A, a gas generator 1A according to the present embodiment includes an igniter (squib) 10 as an igniter, a holder 20 as a base member constituting a part of the housing, and the remainder of the housing. An actuating charge cup (AC cup) 40 serving as a cup member that constitutes the above-mentioned part and a gas generating agent 50 accommodated in a predetermined region inside the housing are mainly provided.

  The igniter 10 is an ignition device for generating a flame, and includes an ignition agent (not shown) and a resistor (not shown) for burning the ignition agent inside. More specifically, the igniter 10 includes a base 11 for inserting and holding a pair of header pins 13 and 14, and a squib cup 12 attached on the base 11, and the header pin inserted into the squib cup 12. A resistor (bridge wire) is attached so as to connect the tips of 13 and 14. The squib cup 12 is filled with an igniting agent so as to surround the resistor or to be in contact with the resistor. Nichrome wire or the like is generally used as the resistor, and ZPP (zirconium / potassium perchlorate), ZWPP (zirconium / tungsten / potassium perchlorate), tricinate, or the like is generally used as the igniting agent. The squib cup 12 is generally made of metal or plastic. In addition, the squib cup 12 may be filled not only with the igniting agent but also with a transfer agent in addition to the igniting agent.

  When a collision is detected, a predetermined amount of current flows through the resistor via the header pins 13 and 14. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and the ignition agent starts burning. The high-temperature flame (gas and particles) generated by the combustion ruptures the squib cup 12 containing the igniting agent and ignites the gas generating agent 50. The time from when the current flows through the resistor until the ignition device is activated is 2 milliseconds or less when a nichrome wire is used as the resistor.

  The above igniter 10 is held by a holder 20. The holder 20 is made of a hollow, substantially cylindrical member, and is formed of a molded product using, for example, an aluminum alloy. The holder 20 includes holding parts 21 and 22 that hold the base part 11 of the igniter 10 from above and below, and a flange part 23 that is a connecting part to the AC cup 40. An O-ring 61 is interposed between the holding portion 21 of the holder 20 and the base portion 11 of the igniter 10. The O-ring 61 is used to hermetically seal a gap generated between the base portion 11 of the igniter 10 and the holding portions 21 and 22 of the holder 20 when the base portion 11 is caulked and fixed. It is a member for hermetically sealing the agent storage chamber. The O-ring 61 is preferably made of a material having sufficient heat resistance and durability. For example, an O-ring made of EPDM resin, which is a kind of ethylene propylene rubber, is suitable. In addition, if a sealing agent is separately applied to this part, the airtight performance is further improved.

  An AC cup 40 is attached to the flange portion 23 of the holder 20. The AC cup 40 is made of a cylindrical member with a bottom, and is attached to the flange portion 23 of the holder 20 so as to cover the igniter 10 held by the holder 20. More specifically, the AC cup 40 includes a side plate portion 41 and a bottom plate portion 42, and a gas generating agent in which the gas generating agent 50 is accommodated between the flange portion 23 of the holder 20 and the squib cup 12 of the igniter 10. The agent storage chamber is partitioned.

  A flange portion 43 is formed at the lower end of the side plate portion 41 of the AC cup 40, and the flange portion 43 and the caulking portion 24 of the holder 20 are caulked and fixed. A sealing agent 62 is applied between the flange portion 23 of the holder 20 and the flange portion 43 of the AC cup 40. The sealant 62 is not essential, but is applied as necessary to ensure a hermetic seal between the flange portion 23 of the holder 20 and the flange portion 43 of the AC cup 40. As the sealant 62, it is preferable to use a material with low moisture permeability and excellent durability, and for example, a silicon sealant is preferably used. Further, when a sealing agent in which a solid component is dissolved in a solvent is used, the housing is preferably caulked and fixed after application and drying of the sealing agent.

  A gas generating agent 50 is stored in the gas generating agent storage chamber defined by the AC cup 40, the holder 20, and the igniter 10. The gas generating agent 50 is ignited and burned by a high-temperature flame introduced from the squib cup 12 of the igniter 10. The AC cup 40 is opened by the pressure of the combustion gas of the gas generating agent 50, and the gas generating agent 50 and its combustion product are led out from the gas generator 1A.

  In order to obtain a gas generator with a desired output, it is necessary to ensure that the AC cup 40 opens at a predetermined pressure. For this reason, as shown in FIGS. 1A and 1B, a score (recess) 46 is formed at a predetermined position of the AC cup 40. The formation location, shape, formation method, etc. of the score 46 will be described later.

  Further, a protrusion 45 is provided on the bottom plate portion 42 of the AC cup 40. This protrusion 45 constitutes the outer dimensions of the gas generator 1A and the drive unit of the pretensioner device by deforming itself when the gas generator 1A is assembled to the drive unit of the pretensioner device to be described later. Absorbs the dimensional error that occurs between the pair of plate-like members, adjusts the clearance between the pair of plate-like members to a desired size after assembly, and generates gas by the pair of plate-like members This is to ensure the fixing of the vessel. The protrusion 45 is formed by, for example, pressing.

  As described above, the gas generating agent 50 accommodated in the gas generating agent accommodating chamber is ignited by the flame supplied from the igniter 10, and is led out of the gas generator 1A together with the gas generated by the combustion. As the gas generating agent 50, a molded body of smokeless explosive (nitrocellulose), a molded body of a composite composition composed of an organic nitrogen compound and an oxidizing agent, or the like is used. In particular, in recent years, non-nitrocellulose-based gas generants that produce very little harmful components such as carbon monoxide have been used as gas generants for pretensioners of seat belt devices.

  As the shape of the molded body of the gas generating agent 50, various shapes such as a granular shape, a pellet shape, a cylindrical shape, and a disk shape are used. In addition, a porous (for example, a single-hole cylindrical shape or a porous cylindrical shape) having a hole in the molded body is also used. These shapes are preferably selected as appropriate according to the specifications of the drive unit of the pretensioner device to which the gas generator is assembled. For example, the shape is such that the gas generation rate changes during combustion of the gas generating agent. The most suitable shape is selected. In addition to the shape of the gas generating agent, the size of the molded body is appropriately selected in consideration of the linear combustion rate of the gas generating agent, the pressure index, and the like. In addition, although the filling amount of a gas generating agent is suitably changed according to the specification of the unit to be assembled, when a smokeless explosive is used, it is usually about 0.2 to 2.0 grams.

  FIG. 2 is a schematic cross-sectional view of the drive unit of the pretensioner device according to Embodiment 1 of the present invention. The drive unit of the pretensioner device in the present embodiment includes the gas generator 1A having the above-described configuration as a gas generation source.

  As shown in FIG. 2, the drive unit of the pretensioner device according to the present embodiment includes a pair of plate-like members 71 and 72, a gas generator 1 </ b> A sandwiched between the pair of plate-like members 71 and 72, It is provided between a pair of plate-like members 71 and 72, and is made of a metal belt 73 that is a driving belt-like member wound so as to surround the gas generator 1A. The pair of plate-like members 71 and 72 are opposed to each other in substantially parallel so that their main surfaces face each other, and the upper end and the lower end of the metal belt 73 respectively contact the pair of plate-like members 71 and 72. It touches. Thereby, the working space 74 is defined by the pair of plate-like members 71 and 72 and the metal belt 73.

  In the working space 74, the housing of the gas generator 1A is fixed by being sandwiched by a pair of plate-like members 71 and 72 from the vertical direction. As a result, the high-pressure gas derived from the gas generator 1A during operation is introduced into the working space 74 located on the side of the gas generator 1A, and is made of metal due to the fluctuation of the gas pressure in the working space 74. The belt 73 is pushed outward. The metal belt 73 is connected to a shaft of a seat belt pretensioner device (not shown), and the seat belt is retracted by rotating the shaft by a predetermined amount by the metal belt.

  As shown in FIGS. 1A and 1B, in the gas generator 1A according to the present embodiment, the boundary between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40 (that is, the bottom plate portion 42). A score 46 is provided on the outer surface of the bottom plate portion 42 so as to partially include a curved portion located at the periphery. In the illustrated gas generator 1 </ b> A, three scores 46 are equally provided along the periphery of the bottom plate portion 42. Each score 46 extends linearly toward the center of the bottom plate portion 42 with the boundary between the side plate portion 41 and the bottom plate portion 42 as the base end. The score 46 is formed by pressing or grinding the AC cup 40.

  As described above, the score 46 is provided on the surface of the AC cup 40 to ensure that the AC cup 40 is opened at a predetermined pressure in order to obtain a gas generator having a desired output. Therefore, the remaining thickness of the AC cup 40 on which the score 46 is formed is adjusted to an optimum thickness so that the AC cup 40 is opened at a predetermined pressure. For example, when the AC cup 40 is formed of an aluminum alloy and the score 46 is shaped as shown in the figure, the remaining thickness of the AC cup 40 in the score 46 portion is preferably set to about 0.3 mm. When such a setting is made, it naturally depends on the shape of the other part of the gas generator 1A, the material of the gas generating agent 50 and the filling amount, etc., but it is preferable in a state where the housing is regulated from above and below. The AC cup 40 can be opened within a range of about 6 MPa to 10 MPa, which is a high internal pressure, and a stable output of the gas generator can be obtained. It should be noted that the length of the score 46 is also appropriately selected as the optimal length.

  FIG. 3A is a diagram schematically showing how a crack generated in a score grows when the gas generator according to the present embodiment is activated. On the other hand, FIG. 3B schematically shows how a crack generated in the score grows when the side-injection type gas generator devised by the present inventors shown in FIG. 11 is operated. It is a figure. Below, with reference to these figures, the difference in the crack growth method in these gas generators will be described.

  First, as shown in FIG. 3B, in the side-injection type gas generator 1H devised by the present inventors, it is formed at a substantially central portion in the vertical direction of the side plate portion 41 of the AC cup 40 during operation. A crack is generated in the score 49, and the crack grows from the upper end and the lower end of the score 49 in the vertical direction (in the direction of arrow A2 in the figure). The crack that has grown from the upper end portion of the score 49 is split into two in the extending direction of the boundary portion (in the direction of arrow A3 in the figure) that is more fragile when the boundary portion between the side plate portion 41 and the bottom plate portion 42 is reached. And cracks grow. The crack grown from this score 49 collides with the crack grown from the other score 49 on the boundary portion. For this reason, the AC cup 40 is broken at the boundary between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40, and the AC cup 40 is opened.

  On the other hand, as shown in FIG. 3A, in the gas generator 1A according to the present embodiment, at the time of operation, the boundary between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40 is the base end. A crack grows downward (in the direction of arrow A1 in the drawing) from the end of the score 46 formed toward the bottom plate portion 42 on the boundary side. Here, cracks hardly occur from the end portion of the score 46 located on the center side of the bottom plate portion 42. This is because the gas generator 1A in the present embodiment is a side-injection type gas generator, and the bottom plate portion 42 of the AC cup is attached to the plate-like member 71 in a state where the gas generator 1A is assembled to the driving unit of the pretensioner device. It is considered that the impact due to the opening of the AC cup 40 escapes to the plate-like member 71 through the bottom plate portion 42 of the AC cup 40 because it is substantially in contact.

  The crack growing from the end of the boundary side of the score 46 has directivity because the score 46 is formed in a straight line, and the side plate portion 41 does not grow in the extending direction of the boundary portion. Grow downwards. For this reason, the AC cup 40 is broken in a region that does not include the boundary portion between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40 and reaches the opening.

  As described above, in the gas generator 1A according to the present embodiment, the gas generator 1A faces the bottom plate portion 42 of the AC cup 40 so as to partially include the boundary portion between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40. Since the score 46 is provided, when the gas generator 1A is operated, a crack occurs from the end of the score 46 toward the lower side of the side plate portion 41, and the boundary between the fragile side plate portion 41 and the bottom plate portion 42 is generated. Generation of cracks in the extending direction of the portion is suppressed. For this reason, it is difficult for the AC cup 40 to be divided on the boundary, which is a cause of fragmentation of the broken fragments, and the broken fragments can be enlarged. For this reason, the number of broken pieces can be reduced.

  FIG. 4A is a photograph of a broken piece that is generated when the gas generator according to Embodiment 1 of the present invention described above is actually operated. On the other hand, FIG. 4 (B) is a photograph of a broken piece that is generated when the side-injection gas generator devised by the present inventors is actually operated.

  As can be seen from these photographs, in the side-injection type gas generator 1H devised by the present inventors, the AC cup 40 is divided into four broken pieces at the time of operation. In the gas generator 1A, the AC cup 40 is only divided into two at the time of operation. In the gas generator 1A in the present embodiment, the side-injection type gas generation devised by the present inventors is performed. It turns out that it succeeded in suppressing the number of fragments to a smaller number than the container 1H. It can also be seen that the size of the broken piece is larger in the gas generator 1A in the present embodiment than in the side-injection type gas generator 1H devised by the present inventors. Therefore, by manufacturing the driving unit for the pretensioner device using the gas generator 1A according to the present embodiment, the risk of the broken pieces being caught between the metal belt and the pair of plate members is greatly reduced. Therefore, the driving unit of the pretensioner device can be obtained in which the desired seat belt retracting performance can be stably obtained.

  In addition, in the gas generator 1A in the present embodiment, the press working at the time of production can be reduced once compared to the side-injection type gas generator 1H devised by the present inventors. In other words, in the side-injection type gas generator 1H devised by the present inventors, the press molding of the AC cup 40 and the press molding of the protrusion 45 are performed by pressing in the longitudinal direction of the AC cup 40. On the other hand, the press molding of the score 49 provided in the side plate portion 41 of the AC cup 40 requires press processing in the lateral direction of the AC cup 40, and therefore requires at least two press processes. On the other hand, in the gas generator 1A according to the present embodiment, the pressing of the score 46 provided on the bottom plate portion 42 of the AC cup 40 can be performed by pressing in the longitudinal direction of the AC cup 40. It is possible to perform the press molding of 40 and the press molding of the protrusion 45 at the same time. For this reason, in the gas generator 1A in the present embodiment, the press working at the time of production can be reduced once compared to the side-injection type gas generator 1H devised by the present inventors. It also has the merit that it can be manufactured at a lower cost.

  5 to 8 are a plan view and a side view showing a modification of the gas generator in the present embodiment. Hereinafter, some specific configurations of the gas generator in the case where the score is formed toward the bottom plate portion with the boundary portion between the side plate portion and the bottom plate portion of the AC cup as the base end will be described by way of example.

  The gas generators 1B and 1C shown in FIGS. 5 and 6 are different from the gas generator 1A shown in FIG. 1 described above in the number of scores. In the gas generator 1 </ b> B shown in FIG. 5, the score 46 is provided so as to extend toward the center of the bottom plate 42 with the boundary between the side plate 41 and the bottom plate 42 of the AC cup 40 as the base end. Are equally provided along the periphery of the bottom plate portion 42. In the gas generator 1 </ b> C shown in FIG. 6, the four scores 46 are evenly provided along the periphery of the bottom plate portion 42. Thus, the number of scores is not particularly limited, and can be changed as appropriate according to the specifications of the driving unit of the pretensioner device to which the gas generator is assembled. However, in order to reduce the number of broken fragments as much as possible, the number of scores is preferably about 1 to 10, more preferably about 2 to 4. In addition, the scores do not necessarily have to be evenly arranged on the peripheral edge of the bottom plate portion of the AC cup, and may be unevenly arranged.

  The gas generators 1D and 1E shown in FIGS. 7 and 8 are different from the gas generator 1A described above, and both ends of the score include a boundary portion between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40. That is, the other end of the score 46 provided so as to extend toward the center of the bottom plate portion 42 with the boundary portion as a base end reaches the other position of the boundary portion. The gas generator 1D shown in FIG. 7 is laid out so that two scores 46 provided on the outer surface of the bottom plate portion 42 intersect at the center of the bottom plate portion 42, and the gas generator shown in FIG. 1E is laid out so that two scores 46 provided on the outer surface of the bottom plate portion 42 do not intersect. Thus, it is not necessary that only one end portion of the score 46 reaches the boundary portion, and both end portions may be provided so as to reach the boundary portion. Further, the shape of the score 46 is not limited to a linear shape, and may be curved.

(Embodiment 2)
FIG. 9A is a schematic cross-sectional view of a gas generator according to Embodiment 2 of the present invention, and FIG. 9B is a plan view of the gas generator according to Embodiment 2 of the present invention. Here, the schematic cross-sectional view shown in FIG. 9A is a schematic cross-sectional view when the gas generator is cut along the line IXA-IXA in FIG. 9B. In addition, the same code | symbol is attached | subjected in the figure about the part similar to 1 A of gas generators in above-mentioned Embodiment 1, and the description is not repeated here.

  As shown in FIGS. 9 (A) and 9 (B), the gas generator 1F in the present embodiment has substantially the same structure as the gas generator 1A in the first embodiment described above. Only the position of the score formed in the cup 40 is different. In gas generator 1F in the present embodiment, score 47 is provided on the outer surface of side plate portion 41 so as to partially include a boundary portion between side plate portion 41 and bottom plate portion 42 of AC cup 40. In the illustrated gas generator 1 </ b> F, three equal scores 47 are provided in the circumferential direction of the side plate portion 41. Each score 47 extends linearly toward the lower side of the side plate portion 41 with the boundary portion between the side plate portion 41 and the bottom plate portion 42 as the base end. The score 47 is formed by pressing or grinding the AC cup 40.

  As described above, even when the score 47 is provided toward the side plate portion 41 of the AC cup 40 so as to partially include the boundary portion between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40, the above-described embodiment. 1, when the gas generator 1 </ b> F is operated, a crack is generated from the lower end portion of the score 47 toward the lower side of the side plate portion 41, and the extending direction of the boundary portion between the fragile side plate portion 41 and the bottom plate portion 42. The occurrence of cracks is suppressed. For this reason, it is possible to increase the size of broken fragments, and as a result, it is possible to reduce the number of broken fragments. Moreover, in the gas generator 1F in this Embodiment, since the upper end part of the score 47 provided in the side-plate part 41 has reached the said boundary part, the press molding of the score 47 can be performed by the vertical direction press work. Thus, as in the first embodiment, the press working at the time of production can be reduced once compared to the side-injection type gas generator 1H devised by the present inventors, and the cost can be reduced. Can be produced.

  Even when the score is formed toward the side plate portion with the boundary portion between the side plate portion and the bottom plate portion of the AC cup as the base end as in the gas generator 1F in the present embodiment, the number of scores and the side plate portion The formation position, width, depth, length, shape, and the like of the score in the circumferential direction can be changed as appropriate. However, in order to prevent fragmentation of broken pieces, the length of the score is preferably ½ or less, more preferably ¼ or less, of the length in the longitudinal direction of the side plate portion of the AC cup. To.

(Embodiment 3)
FIG. 10A is a schematic cross-sectional view of a gas generator according to Embodiment 3 of the present invention, and FIG. 10B is a plan view of the gas generator according to Embodiment 3 of the present invention. Here, the schematic cross-sectional view shown in FIG. 10 (A) is a schematic cross-sectional view when the gas generator is cut along the XA-XA line in FIG. 10 (B). In addition, the same code | symbol is attached | subjected in the figure about the part similar to 1 A of gas generators in above-mentioned Embodiment 1, and the description is not repeated here.

  As shown in FIGS. 10 (A) and 10 (B), gas generator 1G in the present embodiment has substantially the same structure as gas generator 1A in the first embodiment described above. Only the position of the score formed in the cup 40 is different. In the gas generator 1G in the present embodiment, the score 48 straddles the boundary portion and includes the outside of the side plate portion 41 so as to partially include the boundary portion between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40. It is provided so as to reach the outer surface of the bottom plate portion 42 from the surface. In the illustrated gas generator 1G, three scores 48 are equally provided in the circumferential direction of the side plate portion 41. Each score 48 extends linearly across a boundary portion between the side plate portion 41 and the bottom plate portion 42. This score 48 is formed by pressing or grinding the AC cup 40.

  As described above, the score 48 straddles the boundary portion so as to partially include the boundary portion between the side plate portion 41 and the bottom plate portion 42 of the AC cup 40, and the outer surface of the bottom plate portion 42 from the outer surface of the side plate portion 41. When the gas generator 1F is operated, a crack is generated from the lower end portion of the score 48 to the lower side of the side plate portion 41 and is fragile as in the first embodiment described above. Since the occurrence of cracks in the extending direction of the boundary portion between the side plate portion 41 and the bottom plate portion 42 is suppressed, it is possible to increase the size of the broken pieces, and as a result, the number of broken pieces is also reduced. It becomes possible. Further, in the gas generator 1G in the present embodiment, since the press molding of the score 48 can be performed by the vertical direction press working, the present inventors have devised the same as in the first embodiment. Compared to the side-jet type gas generator 1H, the press work during the production can be reduced once, and it can be produced at low cost.

  Even when the score is formed so as to straddle the boundary between the side plate portion and the bottom plate portion of the AC cup as in the gas generator 1G in the present embodiment, the number of scores and the score in the circumferential direction of the side plate portion The formation position, width, depth, length, shape, and the like can be changed as appropriate. However, in order to prevent fragmentation of the broken pieces, the length of the score in the side plate portion is preferably ½ or less, more preferably ¼ or less of the length in the longitudinal direction of the side plate portion of the AC cup. To be.

  In the above-described gas generators 1A to 1G according to Embodiments 1 to 3 of the present invention, the description has been given by exemplifying the case where a score is formed on the outer surface of the AC cup. Of course, it is also possible to form a score on the inner surface. Also in this case, the same effects as those of the first to third embodiments can be obtained.

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

It is the schematic cross section and top view of the gas generator in Embodiment 1 of this invention. It is a schematic cross section of the drive unit of the pretensioner device in Embodiment 1 of the present invention. The crack growth direction at the time of operation of the gas generator according to Embodiment 1 of the present invention is compared with the growth direction of the crack at the time of operation of the side-injection type gas generator devised by the present inventors. It is a schematic diagram for. A photograph comparing a fragment generated when the gas generator according to Embodiment 1 of the present invention is operated and a fragment generated when the side-injection type gas generator devised by the present inventors is operated. It is. It is the top view and side view which show the modification of the gas generator in Embodiment 1 of this invention. It is the top view and side view which show the other modification of the gas generator in Embodiment 1 of this invention. It is the top view and side view which show the further another modification of the gas generator in Embodiment 1 of this invention. It is the top view and side view which show the further another modification of the gas generator in Embodiment 1 of this invention. It is the schematic cross section and top view of the gas generator in Embodiment 2 of this invention. It is the schematic cross section and top view of the gas generator in Embodiment 3 of this invention. It is a side view of the side-injection type gas generator devised by the present inventors.

Explanation of symbols

  1A to 1H Gas generator, 10 igniter, 11 base, 12 squib cup, 13, 14 header pin, 20 holder, 21, 22 holding part, 23 flange part, 24 caulking part, 40 AC cup, 41 side plate part, 42 bottom plate part , 43 collar part, 45 protrusion part, 46-49 score, 50 gas generating agent, 61 O-ring, 62 sealant, 71, 72 plate member, 73 metal belt, 74 working space.

Claims (5)

A pair of plate-like members arranged substantially in parallel with an igniter and a housing containing therein a gas generant containing chamber that contains a gas generant that is ignited by the igniter and generates gas by burning. A gas generator in which the housing is sandwiched and fixed from above and below,
The housing includes a base member that holds the igniter, and a bottomed cylindrical cup member that is attached to the base member and includes a side plate portion and a bottom plate portion that form the gas generating agent storage chamber.
A gas generator in which a score is provided on a surface of the cup member so as to partially include a boundary portion between the side plate portion and the bottom plate portion.   The gas generator according to claim 1, wherein the score is provided on an outer surface of the bottom plate portion with the boundary portion as a base end.   The gas generator according to claim 1, wherein the score is provided on an outer surface of the side plate portion with the boundary portion as a base end.   The gas generator according to claim 1, wherein the score is provided so as to straddle the boundary portion and reach the outer surface of the bottom plate portion from the outer surface of the side plate portion. A pair of plate-like members disposed substantially parallel to each other so that their principal surfaces face each other, a gas generator sandwiched between the pair of plate-like members, and the pair of plate-like members, A driving unit of a pretensioner device comprising a driving belt-like member wound so as to surround the gas generator,
The gas generator includes an igniter and a gas generating agent storage chamber that stores a gas generating agent that is ignited by the igniter and generates gas when burned, and is vertically moved by the pair of plate-like members. A housing fixed by being clamped from the direction,
The housing includes a base member that holds the igniter, and a bottomed cylindrical cup member that is attached to the base member and includes a side plate portion and a bottom plate portion that form the gas generating agent storage chamber.
A driving unit for a pretensioner device, wherein a score is provided on a surface of the cup member so as to include a boundary portion between the side plate portion and the bottom plate portion.