JP4953838B2 - Gas generator - Google Patents

Description

  The present invention relates to a gas generator incorporated in an occupant protection device, and more particularly to a gas generator incorporated in an airbag device mounted on a steering wheel or the like of an automobile.

  2. Description of the Related Art Conventionally, airbag devices, which are occupant protection devices, have been widely used from the viewpoint of protecting occupants such as automobiles. The airbag device is equipped for the purpose of protecting the occupant from the impact caused by the collision of the vehicle or the like. By inflating and deploying the airbag instantaneously at the time of the collision of the vehicle or the like, the airbag functions as a cushion of the occupant. It is to catch the body. The gas generator is incorporated in the airbag device, and igniters (squibs) are ignited by energization from the control unit (actuator) in the event of a vehicle collision, etc., and the gas generating agent is combusted by the flame generated in the igniter. It is a device that instantly generates the gas and thereby inflates and deploys the airbag. Note that the airbag device is mounted on, for example, an automobile steering wheel or an instrument panel.

There are various types of gas generators, and there is a so-called disk-type gas generator as a gas generator that is suitably used for a driver side airbag device equipped on a steering wheel or the like. . A disk-type gas generator has a short cylindrical housing closed at both ends in the axial direction, a gas outlet is provided on the peripheral wall of the housing, and a gas generating agent, an igniter, and the like are accommodated inside the housing. It will be. In this disk-type gas generator, combustion is performed between the combustion chamber containing the gas generating agent and the igniter so that the gas generating agent is reliably ignited by the flame generated in the igniter. It is common to arrange an explosive (enhancer) as an accelerator. Usually, the charge transfer agent is contained in a transfer chamber provided inside a cup-shaped member called an enhancer cup, and the enhancer cup is placed in the combustion chamber so that the transfer chamber faces the ignition part (squib cup) of the igniter. It is arranged in a protruding state. As a document disclosing such a gas generator, there is, for example, Japanese Patent Application Laid-Open No. 2002-370607 (Patent Document 1).
JP 2002-370607 A

  In the gas generator, it is important that the combustion of the gas generant is designed to exhibit desired combustion characteristics so that a desired gas output suitable for inflation of the airbag can be obtained. For that purpose, it is important that the flame energy generated in the igniter is transmitted to the gas generating agent with good controllability, and in particular, it is important to optimize the transmission of the flame energy by the transfer agent. For this reason, in the gas generator disclosed in Patent Document 1 described above, for example, an enhancer cup made of stainless steel or the like having high mechanical strength is used, and an opening having a predetermined size is provided at a predetermined position of the enhancer cup. Thus, the transmission of flame energy due to the combustion of the explosive charge is controlled.

  However, when an enhancer cup having an opening as described above is used, in order to prevent the transfer agent from moving to the combustion chamber or the gas generating agent from moving to the transfer chamber due to vibration or the like, It is necessary to close the opening with a member. Normally, an aluminum foil with an adhesive member applied on one side is used as a sealing member that closes the opening. However, the aluminum foil is very thin and difficult to handle, and the manufacturing process becomes complicated. is there. In addition, in recent years, weight reduction of automobiles has become an increasingly important issue. However, when an enhancer cup made of stainless steel or the like having high mechanical strength is used as described above, the weight of the enhancer cup increases. There is also a problem that the weight of the entire gas generator increases.

  Therefore, it has been studied to use an enhancer cup that has a low mechanical strength and is configured to burst or melt with the ignition of the transfer charge. When such an enhancer cup is used, it is not necessary to provide an opening in the enhancer cup in advance, and the above-described opening closing operation is not required, so that the manufacturing process can be greatly simplified. In addition, if an enhancer cup with low mechanical strength can be used, the enhancer cup itself can be reduced in weight, and not only the weight of the gas generator can be reduced, but also the amount of material used. From the viewpoints of cost reduction and resource protection accompanying the reduction of the cost, it is very suitable. In addition, as a fragile enhancer cup that has low mechanical strength and bursts or melts as ignition agent ignites, for example, the material is made of aluminum, aluminum alloy, or plastic, and the material is iron as usual. Although it is made of metal such as copper or copper, it has been studied to make the thickness very thin.

  However, when the enhancer cup is weakened in this way, if the transfer agent is ignited and the pressure in the transfer chamber is increased and the enhancer cup bursts or melts due to its heat, it is generated in the transfer chamber. The flame immediately flows into the combustion chamber and is transmitted to the gas generating agent. For this reason, the gas generating agent burns rapidly, and it becomes very difficult to adjust the gas output such as maintaining the gas output for a predetermined time. Thus, when the enhancer cup is made weak, there is a problem that it becomes very difficult to control the transmission of flame energy by the charge transfer agent as the mechanical strength decreases.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a gas generator that is easy to manufacture and that can suitably control the transmission of flame energy by a transfer agent.

The gas generator based on this invention is provided with a housing, an igniter, a cup-shaped member, a filter member, and a partition part. The housing is composed of a short cylindrical member composed of a top plate portion and a bottom plate portion that close both ends in the axial direction, and a peripheral wall portion provided with a gas ejection port, and a combustion chamber in which a gas generating agent is accommodated. Is included inside. The igniter includes an igniter that is attached to the bottom plate and contains an igniting agent that ignites during operation. The cup-shaped member includes a heat transfer chamber in which a charge transfer material is accommodated, and is disposed so as to protrude into the combustion chamber so that the heat transfer chamber faces the ignition part. The cup-shaped member is configured such that when the gas generator is in operation, the entire portion facing the transfer chamber is ruptured or melted by the combustion of the transfer charge accompanying the operation of the igniter. . The filter member is formed of a cylindrical member disposed along the inner periphery of the housing so as to surround the combustion chamber. The partition portion is disposed between the cup-shaped member and the filter member so as to surround the outer periphery of the cup-shaped member in the combustion chamber, and is a portion of the combustion chamber located on the outer peripheral side of the cup-shaped member. A part is separated into the space on the cup-shaped member side and the space on the filter member side. The partition wall portion extends from the inner bottom surface of the bottom plate portion toward the top plate portion, and the partition wall portion extends in the combustion chamber into a space on the cup-shaped member side and a space on the filter member side. It is partitioned to a midway position. The height of the partition wall portion is configured to be higher than the height of the igniter when the inner bottom surface of the bottom plate portion is used as a reference.

With this configuration, even when the mechanical strength of the cup-shaped member is lowered, the cup-shaped member is ignited by the flame that flows into the combustion chamber when the gas generator is activated due to rupture or melting. The spread of the generated gas generating agent proceeds so as to bypass the partition portion provided so as to partially divide the combustion chamber, so that the combustion of the gas generating agent accommodated in the combustion chamber is intentionally delayed. It becomes possible. Therefore, it is possible to easily adjust the combustion characteristics of the gas generating agent, and it is possible to prevent the gas generating agent from being burned out in a short time by optimizing according to the specifications. In addition, since it is not necessary to use a cup-shaped member having high mechanical strength, an operation for closing the opening is unnecessary, and the manufacturing is greatly facilitated. Therefore, it is possible to provide a gas generator that is easy to manufacture and that can suitably control the transmission of flame energy by the transfer agent. In addition, with this configuration, it is possible to reliably limit the progress of the combustion of the gas generating agent that tries to spread radially by the partition wall, and the top plate portion side where the partition wall is not provided is provided. The progress of combustion via the path is reliably reproduced. Therefore, it is possible to intentionally delay the progress of combustion of the gas generating agent accommodated in the combustion chamber, and it becomes possible to more easily adjust the combustion characteristics of the gas generating agent.

In the gas generator based on SL invention, the partition wall portion may protrude toward the more the top plate side of the cup-shaped member in the combustion chamber.

  In order to obtain appropriate ignition, the distance from the end on the top plate side of the partition wall portion to the top plate portion in the portion of the combustion chamber containing the gas generating agent is set to 5. It is preferable to be 0 mm or more.

In the gas generator based on the present invention, by contacting an inner circumferential surface of the upper Symbol filter member and the inner bottom surface of the bottom plate portion, that the filter member further comprises a fixing member for fixing to the housing In this case, it is preferable that the partition wall portion is formed integrally and continuously from a portion that contacts the inner bottom surface of the bottom plate portion of the fixing member.

  With this configuration, it is possible to easily provide the partition wall portion in the combustion chamber by extending a part of the fixing member that fixes the filter member. The problem of complication is eliminated.

In the gas generator according to the present invention, the gas generating agent is accommodated in both the space on the cup-shaped member side and the space on the filter member side of the combustion chamber separated by the partition wall. Preferably it is.

  By configuring in this way, it is possible to minimize the reduction in the amount of gas generant filling due to the provision of the partition wall in the combustion chamber, effectively preventing a decrease in the output of the gas generator. Is possible.

  In addition, it is preferable that the distance between the outer peripheral surface of the said cup-shaped member and the inner peripheral surface of the said partition part is 0.1 mm or more and 10.0 mm or less.

  In the gas generator according to the present invention, the cup-shaped member is preferably made of aluminum or an aluminum alloy.

  As described above, if the cup-shaped member is made of aluminum or aluminum alloy, the mechanical strength can be easily reduced as compared with the conventional stainless steel cup-shaped member. The cup-shaped member can be reliably ruptured or melted.

  ADVANTAGE OF THE INVENTION According to this invention, it can be set as the gas generator which can manufacture easily and can control the transmission of the flame energy by a transfer agent suitably.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below shows a case where the present invention is applied to a so-called disk-type gas generator incorporated in an airbag apparatus mounted on a steering wheel or the like of an automobile.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of a gas generator in Embodiment 1 of the present invention. As shown in FIG. 1, the gas generator 1A according to the present embodiment has a short cylindrical housing closed at both ends in the axial direction, and various components are accommodated inside the housing. Yes.

  The short cylindrical housing is formed by combining an initiator shell 10 and a closure shell 20 each formed in a bottomed cylindrical shape. More specifically, the initiator shell 10 has a bottom plate portion 11 and a peripheral wall portion 12, and the closure shell 20 has a top plate portion 21 and a peripheral wall portion 22, and these initiator shell 10 and closure shell. By being combined so that the 20 open ends face each other, a space for accommodating various components is formed therein.

  Each of the initiator shell 10 and the closure shell 20 is made of a metal member such as stainless steel, steel, an aluminum alloy, or a stainless alloy. More specifically, the initiator shell 10 and the closure shell 20 are each forged, drawn, or pressed from a single plate or piece of block-like metal member using a die or the like corresponding to each part. By combining processing and the like, molding is performed by repeated pressurization and flow. For joining the initiator shell 10 and the closure shell 20, electron beam welding, laser welding, friction welding, or the like is preferably used.

  A holding portion 13 is formed at a substantially central portion of the bottom plate portion 11 of the initiator shell 10. This holding part 13 is a part for inserting and holding the igniter 30. Specifically, the igniter 30 is attached to the holding unit 13 from the inside of the initiator shell 10 so that the terminal pin 30b of the igniter 30 is inserted into the opening provided in the holding unit 13, and in this state, The igniter 30 is caulked and fixed to the holding portion 13 of the initiator shell 10 by caulking the caulking portion 14 a provided at the tip toward the igniter 30 side. A harness connector (not shown) for connecting the igniter 30 and the control unit is connected to the terminal pin 30b arranged so as to be exposed to the outside of the housing.

  The igniter 30 is an ignition device for generating a flame, and includes an ignition unit 30a and the terminal pin 30b described above. The ignition unit 30a includes therein an igniting agent that ignites during operation and a resistor for burning the igniting agent. The terminal pin 30b is connected to the ignition unit 30a in order to ignite the igniting agent. More specifically, the igniter 30 includes a base portion through which the pair of terminal pins 30b are inserted and held, and a squib cup attached to the base portion. The tip of the terminal pin 30b inserted into the squib cup is used as the igniter 30. A resistor (bridge wire) is attached so as to be connected, and an igniting agent is filled in the squib cup so as to surround or 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), lead tricinate, or the like is generally used as the igniting agent. The squib cup is generally made of metal or plastic.

  When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 30b. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and the ignition agent starts burning. The high temperature flame generated by the combustion ruptures the squib cup containing the igniting agent. The time from when the current flows through the resistor until the igniter 30 is activated is generally 2 milliseconds or less when a nichrome wire is used as the resistor.

  A seal member 36 is interposed between the igniter 30 and the holding unit 13. The seal member 36 is for hermetically sealing a gap generated between the igniter 30 and the holding unit 13 to hermetically seal a transfer chamber 33 to be described later, and the igniter 30 is caulked to the holding unit 13. When it is fixed, it is inserted into the gap. The seal member 36 is preferably made of a material having sufficient heat resistance and durability. For example, an O-ring made of EPDM resin, which is a kind of ethylene propylene rubber, is preferably used. In addition, if the liquid sealing agent is separately applied to the portion where the sealing member 36 is interposed, the sealing performance of the fire transfer chamber 33 can be further improved.

  An enhancer cup 32 as a bottomed cylindrical cup-shaped member is fixed to the holding portion 13 of the initiator shell 10 so as to cover the igniter 30. The enhancer cup 32 has a top wall portion 32a, a side wall portion 32b, and a flange portion 32c, and includes a fire transfer chamber 33 in which a charge transfer agent 34 is accommodated. The enhancer cup 32 is fixed to the holding part 13 so that the heat transfer chamber 33 provided inside faces the ignition part 30a. More specifically, the enhancer cup 32 is fixed to the holding portion 13 by caulking the flange portion 32 c of the enhancer cup 32 by the caulking portion 14 b provided in the holding portion 13.

  The enhancer cup 32 has no opening in either the top wall portion 32a or the side wall portion 32b, and the enhancer cup 32 is provided in the state where the enhancer cup 32 is fixed to the holding portion 13 of the initiator shell 10. The firebox 33 is completely sealed. The enhancer cup 32 ruptures or melts as the pressure transfer in the transfer chamber 33 increases or the generated heat is transferred when the transfer charge 34 is ignited by the operation of the igniter 30. The mechanical strength is much lower than that of a conventional stainless steel enhancer cup. Therefore, as the material of the enhancer cup 32, aluminum, an aluminum alloy, plastic, or the like is preferably used from the viewpoint of moldability and weight reduction. Further, as a material, a metal such as iron or copper is employed as usual, but it is conceivable to make the thickness very thin.

The charge transfer agent 34 filled in the transfer chamber 33 is ignited by the flame generated by the operation of the igniter 30 and burns to generate hot particles. The charge transfer agent 34 must be capable of reliably starting the gas generating agent 42 described later, and is generally made of a metal powder / oxidant represented by B / KNO ₃ or the like. The composition etc. which become are used. As the explosive charge 34, a powdery one, one molded into a predetermined shape by a binder, or the like is used. Examples of the shape of the transfer charge molded by the binder include various shapes such as a granular shape, a columnar shape, a sheet shape, a spherical shape, a single-hole cylindrical shape, a porous cylindrical shape, and a tablet shape.

  A combustion chamber 40 in which the gas generating agent 42 is accommodated is located in a space surrounding the portion where the enhancer cup 32 is arranged in the space inside the housing formed of the initiator shell 10 and the closure shell 20. More specifically, the enhancer cup 32 described above is disposed so as to protrude into the combustion chamber 40 formed inside the housing, and a portion and a side wall facing the outer surface of the top wall portion 32a of the enhancer cup 32. A space provided in a portion facing the outer surface of the portion 32 b is configured as the combustion chamber 40. Further, a filter member 44 is disposed along the inner periphery of the housing in a space surrounding the combustion chamber 40 in which the gas generating agent 42 is accommodated. The filter member 44 has a cylindrical shape, and the central axis thereof is disposed so as to substantially match the axial direction of the housing.

  The gas generating agent 42 is ignited by hot particles generated by burning the charge transfer agent 34 ignited by the igniter 30, and generates gas by burning. The gas generating agent 42 is generally formed as a molded body containing a fuel, an oxidant, 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. In addition, as the oxidizing agent, for example, nitrate containing a cation selected from alkali metals, alkaline earth metals, transition metals, and ammonia is used. As the nitrate, for example, sodium nitrate, potassium nitrate and the like are preferably used. In addition, examples of the additive include a binder, a slag forming agent, and a combustion adjusting agent. As the binder, for example, an organic binder such as a metal salt of carboxymethyl cellulose or a stearate, or an inorganic binder such as synthetic hydroxytalcite or acidic clay can be suitably used. As the slag forming agent, silicon nitride, silica, acid clay, etc. can be suitably used. Moreover, as a combustion regulator, a metal oxide, ferrosilicon, activated carbon, graphite, etc. can be used suitably.

  The shape of the molded body of the gas generating agent 42 includes various shapes such as granules, pellets, columns, and disks. In addition, a porous (for example, a single-hole cylindrical shape or a porous cylindrical shape) having a hole inside the molded body is also used. These shapes are preferably selected as appropriate according to the specifications of the airbag apparatus in which the gas generator 1A is incorporated. For example, a shape in which the gas generation rate changes with time during combustion of the gas generating agent 42 is selected. It is preferable to select an optimal shape according to the specifications. In addition to the shape of the gas generating agent 42, it is preferable to appropriately select the size and filling amount of the molded body in consideration of the linear combustion rate, the pressure index, etc. of the gas generating agent 42.

  As the filter member 44, for example, a wire or net made of a metal such as stainless steel or steel, or a material that is pressed and hardened by pressing is used. Specifically, a knitted wire mesh, a plain weave wire mesh, an assembly of crimped metal wires, or the like is used. When the working gas generated in the combustion chamber 40 passes through the filter member 44, the filter member 44 functions as a cooling means for cooling the working gas by taking away the high-temperature heat of the working gas. It also functions as a removing means for removing residues (slag) and the like contained in the gas. Therefore, in order to sufficiently cool the working gas and prevent the residue from being discharged to the outside, it is necessary to ensure that the working gas generated in the combustion chamber 40 passes through the filter member 44. It is.

  A plurality of gas outlets 23 are provided on the peripheral wall portion 22 of the closure shell 20 that faces the filter member 44. The gas outlet 23 is for leading the working gas that has passed through the filter member 44 to the outside of the housing. A seal member 24 is affixed to the main surface located on the filter member 44 side of the peripheral wall portion 22 of the closure shell 20 so as to close the gas ejection port 23. As the sealing member 24, an aluminum foil or the like having an adhesive member applied on one side is used. Thereby, the airtightness of the combustion chamber 40 is ensured.

  A closure shell side holding member 50 for fixing the upper end of the filter member 44 to the housing is disposed at the end of the closure shell 20 on the top plate portion 21 side in the space inside the housing. The closure shell side holding member 50 includes a first contact portion 51 that contacts the top plate portion 21 of the closure shell 20 and a second contact portion 52 that contacts the inner peripheral surface of the upper end portion of the filter member 44. ing. Inside the closure shell side holding member 50, a cushion material 46 is disposed so as to contact the gas generating agent 42 accommodated in the combustion chamber 40. The cushion material 46 is provided for the purpose of preventing the gas generating agent 42 made of a molded body from being pulverized by vibration or the like, and a ceramic fiber molded body, foamed silicon, or the like is preferably used.

  On the other hand, an initiator shell side holding member 60 for fixing the lower end of the filter member 44 to the housing is disposed at the end of the initiator shell 10 on the bottom plate portion 11 side in the space inside the housing. The initiator shell side holding member 60 includes a first contact portion 61 that contacts the inner bottom surface of the bottom plate portion 11 of the initiator shell 10, a second contact portion 62 that contacts the inner peripheral surface of the lower end portion of the filter member 44, and The first abutting portion 61 has a partition wall portion 63 erected from the inner end portion toward the combustion chamber 40 side.

  The closure shell side holding member 50 and the initiator shell side holding member 60 are formed by, for example, pressing a single metal plate-like member, and preferably steel plates such as ordinary steel and special steel. (For example, a cold rolled steel plate (SPCC), a stainless steel plate (SUS304), etc.) is used. Since the closure shell side holding member 50 and the initiator shell side holding member 60 are formed by bending a part of the metal plate-like member as described above, the closure shell side holding member 50 and the initiator shell side holding member are held. Each member 60 has moderate elasticity. Therefore, the second contact portion 52 of the closure shell side holding member 50 and the second contact portion 62 of the initiator shell side holding member 60 are in appropriate pressure contact with the inner peripheral surface of the filter member 44, respectively. As a result, the filter member 44 is held and fixed to the housing. Each of the closure shell side holding member 50 and the initiator shell side holding member 60 includes a gap between the upper end of the filter member 44 and the top plate portion 21 of the closure shell 20 and the lower end of the filter member 44 and the bottom plate of the initiator shell 10. The function which prevents the outflow of the gas from the clearance gap between the parts 11 is also performed.

  A partition wall portion 63 extending from the initiator shell side holding member 60 is disposed between the enhancer cup 32 and the peripheral wall portions 12 and 22 of the housing so as to surround the outer periphery of the enhancer cup 32 in the combustion chamber 40. By extending from the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 toward the top plate portion 21 of the closure shell 20, the combustion chamber 40 is made to extend in the direction in which the partition wall 63 extends in the space S 1 on the enhancer cup 32 side and the peripheral wall portion 12 of the housing. , 22 space S3 is divided to a middle position. That is, the partition wall 63 divides a portion of the combustion chamber 40 located on the outer peripheral side of the enhancer cup 32 into a space S1 on the enhancer cup 32 side and a space S3 on the peripheral wall portions 12 and 22 side of the housing. These spaces S1 and S3 communicate with each other through a space where the partition wall 63 of the combustion chamber 40 is not provided, that is, the space S2 on the closure shell 20 side.

  Next, the procedure for assembling the gas generator 1A shown in FIG. 1 will be described with reference to FIG. First, the igniter 30 is caulked and fixed by attaching the seal member 36 to the holding portion 13 of the initiator shell 10. Then, the enhancer cup 32 in which the transfer charge 34 is accommodated is caulked and fixed to the holding portion 13 of the initiator shell 10. Next, the initiator shell side holding member 60 and the filter member 44 are inserted and arranged toward the inner bottom surface of the initiator shell 10. The gas generating agent 42 is filled inside the filter member 44, and the closure shell side holding member 50 having the cushion material 46 interposed is inserted into the upper end portion of the filter member 44. Thereafter, the closure shell 20 whose gas outlet 23 is closed by the seal member 24 is placed on the initiator shell 10, and the initiator shell 10 and the closure shell 20 are welded together. Thus, the assembly of the gas generator 1A having the configuration shown in FIG. 1 is completed.

  Here, in the gas generator 1A in the present embodiment, since the enhancer cup 32 is not provided with an opening, the step of filling the transfer chamber 33 provided in the enhancer cup 32 with the transfer agent 34 is extremely necessary. Easy to do. This is because the enhancer cup 32 itself is composed of a fragile member having low mechanical strength so that the enhancer cup 32 is ruptured or melted during operation of the gas generator 1A. That is, the process of closing the opening provided in the enhancer cup for filling the transfer charge, which was necessary when assembling the conventional gas generator, is no longer required, and the manufacturing process is greatly simplified. Can do.

  Next, operation | movement of 1 A of gas generators in this Embodiment is demonstrated. When a vehicle on which the gas generator 1A according to the present embodiment is mounted collides, the collision is detected by a collision detection unit provided separately in the vehicle, and the igniter 30 is operated based on this. The charge transfer agent 34 accommodated in the transfer chamber 33 is ignited and burned by the flame generated by the operation of the igniter 30, and generates a large amount of heat particles. When the pressure in the enhancer cup 32 increases due to the combustion of the charge transfer agent 34, the enhancer cup 32 is ruptured or melted by the pressure or heat, and the above-described hot particles flow into the combustion chamber 40.

  The gas generating agent 42 accommodated in the combustion chamber 40 is ignited and burned by the flowing heat particles, and a large amount of working gas is generated. The working gas generated in the combustion chamber 40 passes through the filter member 44. At this time, heat is taken away by the filter member 44 and cooled, and the residue contained in the working gas is removed by the filter member 44, and the housing. Then, the gas flows into the outer peripheral edge of the housing shell, and is then ejected from the gas outlet 23 provided in the peripheral wall portion 22 of the closure shell 20 to the outside of the housing. The jetted gas is introduced into an airbag provided adjacent to the gas generator, and the airbag is inflated and deployed.

  Below, when it is set as 1 A of gas generators in this Embodiment, the mechanism in which transmission of the flame energy by a charge transfer agent becomes controllable suitably is demonstrated.

  As shown in FIG. 1, in the gas generator 1 </ b> A according to the present embodiment, the partition wall portion 63 formed by a part of the initiator shell side holding member 60 is formed in the combustion chamber 40 with a predetermined distance D from the enhancer cup 32. Is arranged. Here, in the gas generator 1A in the present embodiment, the distance D is set to be larger than the minimum outer dimension of the gas generating agent 42, and the partition wall 63 of the combustion chamber 40 is not located. The gas generating agent not only in the space S2 and the space S3 between the partition wall 63 and the filter member 44 but also in the space S1 between the inner peripheral surface of the partition wall 63 and the outer peripheral surface of the side wall 32b of the enhancer cup 32. 42 is filled.

On the other hand, the height H _A of the partition wall 63 with respect to the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 is higher than the height H of the enhancer cup 32 with reference to the inner bottom surface of the bottom plate portion 11 of the initiator shell 10. It has been adjusted to be. The gas generator 1A according to the present embodiment is configured such that the partition wall 63 protrudes further toward the top plate 21 side of the closure shell 20 than the enhancer cup 32 in the combustion chamber 40. ing.

  With the above-described configuration, the gas generating agent 42 ignited by the flame flowing into the combustion chamber 40 in a state where the charge transfer agent 34 is burned by the operation of the igniter 30 and the enhancer cup 32 is ruptured or melted. Although the spread of the flame tends to progress radially around the transfer chamber 33, the combustion of the gas generating agent 42 in the space S1 is blocked by the partition wall 63, and the progress is suppressed. . Therefore, the combustion of the gas generating agent 42 in the space S1 does not immediately lead to the combustion of the gas generating agent 42 in the space S3, and the combustion of the gas generating agent 42 in the space S2 proceeds in a detour so as to go around the partition wall 63. The combustion of the gas generating agent 42 in the space S3 is started. The spread of the gas generating agent 42 is schematically represented by broken-line arrows in FIG. As described above, in the gas generator 1A according to the present embodiment, since the progress of the combustion of the gas generating agent 42 in the combustion chamber 40 is intentionally delayed by the partition wall 63, the arrangement of the partition wall 63 By appropriately adjusting the position, shape, size, and the like, the combustion characteristics of the gas generating agent 42 can be optimized according to the specifications.

  Further, when the enhancer cup 32 is constituted by a member having low mechanical strength, an impact when the enhancer cup 32 is ruptured or melted by the combustion of the transfer powder 34 is directly applied to the filter member 44. However, the filter member 44 may be damaged by disposing the partition wall 63 between the enhancer cup 32 and the filter member 44 as in the gas generator 1A in the present embodiment. The effect which is prevented in advance is also obtained.

In the gas generator 1A according to the present embodiment, the distance D between the inner peripheral surface of the partition wall 63 and the outer surface of the side wall 32b of the enhancer cup 32 is 0.1 mm or greater and 10.0 mm or less. Have been adjusted so that. With this configuration, it is possible to effectively delay the progress of the combustion of the gas generating agent 42 and to select whether or not to fill the space S1 with the gas generating agent 42. Further, in the gas generator 1A according to the present embodiment, the height H _{A based} on the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 of the partition wall portion 63 is the height H _G of the space S2 of the combustion chamber 40. It is selected to be 5.0 mm or more. Here, the height H _G of the space S2 of the combustion chamber 40 is such that the top plate from the end on the top plate portion 21 side of the closure shell 20 of the partition wall 63 in the portion of the combustion chamber 40 in which the gas generating agent 42 is accommodated. This corresponds to the distance toward the portion 21. That is, in the gas generator 1A in the present embodiment, the distance is from the upper end of the partition wall 63 to the lower surface of the cushion material 46. With this configuration, a path for the spread of the gas generating agent 42 that bypasses the partition wall 63 is secured, and the combustion of the gas generating agent 42 in the space S2 reliably reaches the space S3. Become.

FIG. 2 is a schematic cross-sectional view showing a modification of the gas generator in the present embodiment. In the gas generator 1A in the embodiment shown in FIG. 1 described above, the height _HA of the partition wall 63 with respect to the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 is the inner bottom surface of the bottom plate portion 11 of the initiator shell 10. The case where it was adjusted so as to be higher than the height H of the enhancer cup 32 based on the above was illustrated. However, it is not necessarily configured in this way, and the height _HA of the partition wall 63 may be set lower. In the gas generator 1B according to the modification shown in FIG. 2, the height H _A of the partition wall 63 with respect to the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 is based on the inner bottom surface of the bottom plate portion 11 of the initiator shell 10. The height of the enhancer cup 32 is adjusted to be lower than H. Even in such a configuration, the combustion of the gas generating agent 42 in the space S1 is still blocked by the partition wall 63, and the combustion of the gas generating agent 42 in the space S1 is immediately performed in the space S3. Will not lead to combustion. For this reason, the combustion of the gas generating agent 42 in the space S2 detours around the partition wall 63 to start the combustion of the gas generating agent 42 in the space S3, and the gas in the combustion chamber 40 is started. The progress of combustion of the generating agent 42 can be intentionally delayed.

However, the height H _A of the partition wall 63 is preferably higher than the height h of the igniter 30 with respect to the inner bottom surface of the bottom plate portion 11 of the initiator shell 10. When the height H _A of the partition wall 63 is set lower than the height h of the igniter 30, the spread of the gas generating agent 42 ignited by the flame flowing into the combustion chamber 40 causes the transfer chamber 33 to be ignited. It progresses radially as the center, and reaches the filter member 44 without bypassing the partition wall 63. Accordingly, the progress of combustion of the gas generating agent 42 in the combustion chamber 40 can hardly be delayed, and the combustion characteristics of the gas generating agent 42 cannot be substantially adjusted.

(Example)
FIG. 3 verifies how much the combustion characteristics of the gas generating agent can be adjusted by the above-described partition wall by actually producing and operating the gas generator shown in FIGS. 1 and 2. It is a graph which shows the result of the done test. The graph shown in FIG. 3 is a so-called PT (pressure-time) graph, in which the vertical axis represents the pressure in the tank and the horizontal axis represents time.

Example 1
Nitrogen-containing organic compound component: guanidine nitrate: 53.0 parts by weight; oxidant component: nitrate based on strontium nitrate: 43.6 parts by weight; acidic clay as binder: 3.0 parts by weight; and magnesium stearate as lubricant : 0.4 part by weight was dry-mixed with a V-type mixer. Then, it was press-molded into a shape having a diameter of 6.1 mm and a height of 1.5 mm using a rotary tableting machine, and dried at 105 ° C. for 15 hours to obtain a tablet of the gas generant composition used in this example. 60 g of this tablet was loaded into the combustion chamber of the gas generator 1A having the configuration shown in FIG. Note that the height H _A of the partition wall relative to the inner bottom surface of the bottom plate portion of the initiator shell was 30 mm. Further, 1.5 g of boron nitrate was used as the transfer agent. After the gas generator was attached to a tank having an internal volume of 60 liters, the gas generator was operated to release the gas into the tank, and the change over time in the tank internal pressure was measured.

(Example 2)
60 g of the same gas generant composition tablet as in Example 1 was loaded into the combustion chamber of the gas generator 1B having the configuration shown in FIG. The height H _A of the partition wall relative to the inner bottom surface of the bottom plate portion of the initiator shell was 20 mm. Further, the same charge transfer agent as that in Example 1 was used. After the gas generator was attached to a tank having an internal volume of 60 liters, the gas generator was operated to release the gas into the tank, and the change over time in the tank internal pressure was measured.

, (Comparative example)
60 g of a tablet of the same gas generant composition as in Example 1 described above was loaded into a combustion chamber of a gas generator similar to the gas generator 1A having the configuration shown in FIG. Further, the same charge transfer agent as that in Example 1 was used. After the gas generator was attached to a tank having an internal volume of 60 liters, the gas generator was operated to release the gas into the tank, and the change over time in the tank internal pressure was measured.

  As shown in FIG. 3, in Example 1 and Example 2, it can be seen that the pressure rise is not as steep as the comparative example, and the pressure rises gently. It can also be seen that the degree of pressure rise can be easily controlled by adjusting the height of the partition wall. That is, by applying the present invention, it is possible to intentionally delay the progress of the combustion of the gas generating agent in the combustion chamber, and therefore, a gas generator having a gas output optimized according to the specifications of the airbag device It was proved that can be manufactured easily.

(Embodiment 2)
FIG. 4 is a schematic cross-sectional view of a gas generator according to Embodiment 2 of the present invention. 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 FIG. 4, in the gas generator 1 </ b> C according to the present embodiment, a partition wall portion 63 constituted by a part of the initiator shell side holding member 60 is disposed close to the enhancer cup 32. Here, in the gas generator 1 </ b> C in the present embodiment, the distance D between the inner peripheral surface of the partition wall 63 and the outer surface of the side wall 32 b of the enhancer cup 32 is smaller than the minimum outer dimension of the gas generating agent 42. The gas generating agent 42 is not filled in the space S1 of the combustion chamber 40, which is a space between the inner peripheral surface of the partition wall portion 63 and the outer peripheral surface of the side wall portion 32b of the enhancer cup 32. It is configured.

  Even in such a configuration, although the filling amount of the gas generating agent is reduced by the volume of the space S1, the gas generating agent in the combustion chamber 40 is separated by the partition wall 63 as in the case of the first embodiment. Since the progress of the combustion of 42 is intentionally delayed, the combustion characteristics of the gas generating agent 42 can be easily adjusted.

(Embodiment 3)
FIG. 5 is a schematic cross-sectional view of a gas generator according to Embodiment 3 of the present invention. 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 FIG. 5, in the gas generator 1 </ b> D in the present embodiment, the partition wall portion is formed by the partition wall forming member 70 provided separately from the initiator shell side holding member 60. Specifically, the initiator shell side holding member 60 has a first contact portion 61 that contacts the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 and a second contact that contacts the inner peripheral surface of the lower end portion of the filter member 44. Only the contact portion 62 is included. On the other hand, the partition wall forming member 70, which is configured separately from the initiator shell side holding member 60, is directed to the contact portion 71 that contacts the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 and the combustion chamber 40 side. And a partition wall portion 73 standing upright. The initiator shell side holding member 60 and the partition wall forming member 70 are integrated by fitting their ends together and attached to the inner bottom surface of the bottom plate portion 11 of the initiator shell 10.

  The initiator shell side holding member 60 and the partition wall forming member 70 are formed by, for example, pressing a single metal plate-like member, and are preferably made of ordinary steel or special steel. A steel plate (for example, a cold rolled steel plate (SPCC), a stainless steel plate (SUS304), etc.) is used.

  Even in such a configuration, the progress of the combustion of the gas generating agent 42 in the combustion chamber 40 is intentionally delayed by the partition wall 73 as in the case of the first embodiment described above. It becomes possible to easily adjust the combustion characteristics of the gas generating agent 42.

(Embodiment 4)
FIG. 6 is a schematic cross-sectional view of a gas generator according to Embodiment 4 of the present invention. 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 FIG. 6, in the gas generator 1 </ b> E in the present embodiment, the top wall portion 32 a of the enhancer cup 32 is pressed against the top plate portion 21 of the closure shell 20 via the closure shell side holding member 50. It is configured. Therefore, the combustion chamber 40 in which the gas generating agent 42 is accommodated is formed only in the space surrounding the side wall portion 32 b of the enhancer cup 32. Further, the partition wall portion 63 constituted by a part of the initiator shell side holding member 60 extends from the inner bottom surface of the bottom plate portion 11 of the initiator shell 10 toward the top plate portion 21 of the closure shell 20. In the extending direction, the combustion chamber 40 is partitioned into a space S1 on the enhancer cup 32 side and a space S3 on the peripheral wall portions 12 and 22 side of the housing up to an intermediate position. These spaces S1 and S2 communicate with each other by a space where the partition wall 63 of the combustion chamber 40 is not provided, that is, the space S2 on the closure shell 20 side. The cushion material 46 is fitted into the initiator shell side holding member 60.

  Even in such a configuration, as in the case of the above-described first embodiment, the spread of the gas generating agent 42 in the space S1 is blocked by the partition wall 63, and the progress thereof is suppressed. Become. Therefore, the combustion of the gas generating agent 42 in the space S1 does not immediately lead to the combustion of the gas generating agent 42 in the space S3, and the combustion of the gas generating agent 42 in the space S2 proceeds in a detour so as to go around the partition wall 63. The combustion of the gas generating agent 42 in the space S3 is started. The spread of the gas generating agent 42 is schematically represented by broken-line arrows in FIG. As described above, even in the case of the configuration like the gas generator 1E in the present embodiment, combustion of the gas generating agent 42 in the combustion chamber 40 by the partition wall 63 is performed as in the case of the first embodiment. Therefore, the combustion characteristics of the gas generating agent 42 can be easily adjusted.

  In the first to fourth embodiments described above, the case where the partition wall portion is configured to be formed by an internal component part configured separately from the housing has been described as an example. However, the partition wall portion is the housing. Of course, it is also possible to adopt a configuration that stands directly from above. In that case, it is not limited to the case where the partition wall portion is erected from the bottom plate portion of the initiator shell, but when the partition wall portion is erected from the peripheral wall portion of the initiator shell or from the top plate portion or the peripheral wall portion of the closure shell. It is possible to adopt various configurations such as when standing. Even in such a case, if a configuration in which at least a part of the combustion chamber is separated by the partition wall without being completely partitioned by the partition wall, the object of the present invention is to adjust the combustion characteristics of the gas generating agent. Is achievable.

  As described above, the above-described embodiment and its modifications 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 a schematic cross section of the gas generator in Embodiment 1 of the present invention. It is a schematic cross section which shows the modification of the gas generator in Embodiment 1 of this invention. It is a graph which shows the result of having performed the performance test of the gas generator shown to FIG. 1 and FIG. It is a schematic cross section of the gas generator in Embodiment 2 of the present invention. It is a schematic cross section of the gas generator in Embodiment 3 of the present invention. It is a schematic cross section of the gas generator in Embodiment 4 of the present invention.

Explanation of symbols

  1A to 1E Gas generator, 10 Initiator shell, 11 Bottom plate part, 12 Peripheral wall part, 13 Holding part, 14a, 14b Caulking part, 20 Closure shell, 21 Top plate part, 22 Peripheral wall part, 23 Gas outlet, 24 Seal member 30 igniter, 30a ignition part, 30b terminal pin, 32 enhancer cup, 32a top wall part, 32b side wall part, 32c flange part, 33 transfer chamber, 34 transfer agent, 36 seal member, 40 combustion chamber, 42 gas generation Agent, 44 filter member, 46 cushion material, 50 closure shell side holding member, 51 first contact portion, 52 second contact portion, 60 initiator shell side holding member, 61 first contact portion, 62 second contact Part, 63 partition part, 70 partition part forming member, 71 contact part, 73 partition part.

Claims (7)

A short cylindrical housing that includes a combustion chamber in which a gas generating agent is housed, and includes a top plate portion and a bottom plate portion that close both ends in the axial direction, and a peripheral wall portion provided with a gas ejection port;
An igniter including an igniter that is attached to the bottom plate and contains an igniting agent that ignites during operation;
The flame-transferring chamber transfer charge is accommodated includes therein, the heat transfer firebox is arranged to protrude into the combustion chamber so as to face the igniter, the by combustion of the transfer charge accompanying the operation of the igniter A cup-shaped member in which the entire portion facing the transfer chamber is ruptured or melted;
A cylindrical filter member disposed along the inner periphery of the housing so as to surround the combustion chamber;
A part of the portion of the combustion chamber located on the outer peripheral side of the cup-shaped member is disposed between the cup-shaped member and the filter member so as to surround the outer periphery of the cup-shaped member in the combustion chamber. A partition part that separates the space on the cup-shaped member side and the space on the filter member side;
The partition wall portion extends from the inner bottom surface of the bottom plate portion toward the top plate portion, and the combustion chamber is located at an intermediate position in a direction in which the partition wall portion extends into the space on the cup-shaped member side and the space on the filter member side. Partition to
The gas generator, wherein the height of the partition wall is higher than the height of the igniter when the inner bottom surface of the bottom plate is used as a reference. The gas generator according to claim 1 , wherein the partition wall portion protrudes further toward the top plate portion side than the cup-shaped member in the combustion chamber. Distance toward from the top plate portion of the end portion of the partition portion in the portion where the gas generating agent is accommodated in the combustion chamber to the top plate portion is 5.0mm or more, according to claim 1 or 2 A gas generator according to 1. By contact with the inner bottom surface of the inner peripheral surface and the bottom plate portion of the front Symbol filter member, and a fixing member for fixing the filter member to the housing,
The gas generator according to any one of claims 1 to 3 , wherein the partition wall portion is provided integrally and continuously from a portion that contacts the inner bottom surface of the bottom plate portion of the fixing member. Said gas generating agent, wherein is also housed in one and the cup-shaped member side space of the combustion chamber separated by a partition portion of the filter member side of the space, according to any one of claims 1 to 4 Gas generator. The gas generator according to any one of claims 1 to 5 , wherein a distance between an outer peripheral surface of the cup-shaped member and an inner peripheral surface of the partition wall is 0.1 mm or greater and 10.0 mm or less. The gas generator according to any one of claims 1 to 6 , wherein the cup-shaped member is made of aluminum or aluminum alloy.

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