JP2017193227A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gas generator which prevents breakage and scattering of a housing even when a pressure in the housing rapidly increases and achieves weight reduction compared to conventional gas generators.SOLUTION: A gas generator 100 includes: an elongated cylindrical housing 10 including an operative gas generation chamber 13 where an operative gas is generated by burning a gas generating agent enclosed therein, and a filter chamber 14 which stores a filter 37 through which the operative gas passes; and an igniter 30 capable of igniting and burning the gas generating agent 36 in the operative gas generation chamber 13. First gas discharge ports 15 for discharging the operative gas to the outside are provided at a peripheral wall part of a portion of the housing 10 which defines the filter chamber 14, and second gas discharge ports 16 closed by a cylindrical member 33 are provided at a peripheral wall part of a portion of the housing 10 which defines the operative gas generation chamber 13. The cylindrical member 33 is broken at a portion contacting with the second gas discharge ports 16 when an internal pressure of the housing 10 is higher than that of normal operation time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gas generator incorporated in an airbag device as an occupant protection device mounted on an automobile or the like, and more particularly to a so-called cylinder type gas generator having a long cylindrical outer shape. .

  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. An airbag device is installed in a vehicle or the like for the purpose of protecting an occupant from an impact caused by a vehicle or the like, and is an airbag that is deployed by instantly inflating and deploying the airbag at the time of a vehicle or the like collision. It is intended to catch the passenger's body. The gas generator is a device that is incorporated in the airbag device and inflates and deploys the airbag by instantaneously generating gas when a vehicle or the like collides.

  Gas generators of various configurations exist based on specifications such as installation positions and outputs with respect to vehicles and the like. One of them is a gas generator having a structure called “cylinder type”. The cylinder type gas generator has a long cylindrical shape, and is suitably incorporated in a side airbag device, a curtain airbag device, a knee airbag device, or the like. In the case of being incorporated in these airbags, it is required to operate faster than in the case of being incorporated in a driver seat and a passenger seat airbag.

  Further, the gas generator is required to operate normally at a predetermined installation environment temperature. For example, in Patent Literature 1, when the pressure inside the housing changes (increases) according to the installation environment temperature, the temperature of the generated gas is suppressed by reducing the explosive combustion speed inside the housing according to the pressure change. A gas generator that can be used is disclosed. In this gas generator, when operating in a state where the environmental temperature is raised, the gas passage part expands compared to the normal operation, and the generated gas inside the housing whose temperature is suppressed passes through the filter and passes through the filter to the outside of the housing. It is possible to reduce damage to the airbag on the side where the generated gas is introduced.

JP 2013-43595 A

  However, for some reason (such as when a fire occurs) in a vehicle or the like equipped with an air bag apparatus incorporating a gas generator, the gas generator is heated from the outside, and the gas generating agent burns ( Hereinafter, such a state may be referred to as an abnormal operation.) The pressure inside the housing suddenly increases. In the gas generator disclosed in Patent Document 1, the gas ejection hole provided in the housing is used. Since the total area of the housing itself does not change, unless the housing thickness (plate thickness) is sufficiently thick, it may not be enough to cope with the pressure change, and the housing will break or scatter. There is a concern that That is, in view of the above viewpoint, it is difficult to reduce the thickness of the housing of the gas generator of Patent Document 1 by reducing the thickness.

  Therefore, the present invention prevents the housing from being broken and scattered and stably controls the operation even when the pressure inside the housing suddenly increases for some reason without increasing the thickness of the housing as much as the conventional one. Therefore, an object of the present invention is to provide a cylinder type gas generator that is lighter than conventional ones.

(1) In the gas generator of the present invention, a working gas generation chamber in which a working gas is generated by burning a gas generating agent contained therein, and the working gas generated in the working gas generation chamber pass therethrough. A long cylindrical housing containing a filter chamber in which the filter is accommodated, and an ignition powder. The working gas generation chamber is sandwiched together with the filter at one axial end of the housing. Gas generating agent ignition means arranged so as to ignite and burn the gas generating agent in the working gas generating chamber, and the peripheral wall portion of the portion defining the filter chamber of the housing includes A plurality of first gas discharge ports for discharging the working gas that has passed through the filter to the outside are provided, and the peripheral wall portion of the housing that defines the working gas generation chamber is closed by a closing member. Has been provided with a plurality of second outlet is provided, wherein the closing member is characterized in that it is intended to break at the portion when the housing internal pressure is higher than during normal operation in contact with the second outlet.

(2) In the gas generator of the above (1), it is more preferable that the breaking pressure of the closing member is smaller than the breaking pressure of the housing.

  According to the configuration of (1) or (2) above, the gas generating agent is burned for some reason (fire or the like) and gas is generated, and the housing internal pressure is higher than that during normal operation. In this case, since the gas is released not only from the first discharge port but also from the second discharge port, it is possible to prevent the housing from being ruptured or broken. Therefore, even when the internal pressure of the housing suddenly increases without increasing the thickness of the housing as much as before, the housing can be prevented from being broken and scattered, and the operation can be stably controlled. It is possible to provide a cylinder type gas generator that is lighter than that. In particular, since the gas discharged from the second discharge port is discharged to the outside of the gas generator without passing through the filter means, there is less resistance to gas release, and compared to the case where it passes through the filter means. Gas can be released quickly.

(3) In the gas generator of the above (2), it is preferable that the breaking pressure of the closing member satisfies the following relationship.
Maximum internal pressure of the gas generator during operation at 120 ° C. <rupture pressure of the closing member <break pressure of the housing

  According to the configuration of (3) above, at the highest temperature (120 ° C.) assumed during normal operation, no gas is released from the second gas discharge port, and the gas generator is not operated during abnormal operation. Even when the internal pressure increases abnormally, the gas is discharged from the second gas discharge port before the housing breaks, so that the operation of the gas generator can be controlled more stably.

(4) In the gas generators of (1) to (3), it is preferable that the plurality of second discharge ports are provided in at least one row at equal intervals in the circumferential direction of the housing.

  When two or more second discharge ports are provided in at least one row at equal intervals in the circumferential direction of the housing, the thrust generated by the ejection of the gas discharged from each second discharge port is directed to the center of the housing, and thus cancels out. Therefore, according to the configuration of (4) above, it is possible to prevent the gas generator from flying during abnormal operation. Providing an even number of second discharge ports at equal intervals in the circumferential direction of the housing allows a pair of second discharge ports facing each other to be formed at one time during punching or the like. It is preferable in terms of ease and production cost.

(5) In the gas generators of the above (1) to (4), the closing member has a cylindrical portion formed so as to close at least the second discharge port in the working gas generation chamber. It is preferable that the bottomed cylindrical member is a part of the cylindrical member and the gas generating agent is sealed inside.

  According to the configuration of (5) above, the bottomed cylindrical member can be a member having both a closing function as a closing member and a storage function as a gas generating agent storage container, so the number of parts is small. And it can be set as the gas generator which manufacture (assembly) is easy rather than sticking a sealing member on the inner wall of a 2nd discharge port.

(6) As another aspect, in the gas generators of the above (1) to (4), a first cylindrical portion and a peripheral wall portion having a diameter smaller than that of the first cylindrical portion and facing the second discharge port. A ring-shaped member that includes a bottomed tubular member that seals the gas generating agent therein, and the closing member is fitted to the second tubular portion. It may be.

  According to the configuration of (6) above, since the thickness, material, or strength of the closing member can be easily changed as appropriate, the breaking condition during abnormal operation can be easily controlled.

(7) In the gas generators of the above (1) to (6), it is preferable that the second discharge port is formed closer to the gas generating agent ignition means than the center of the working gas generation chamber.

  According to the configuration of (7) above, the second discharge port is provided at a position relatively distant from the first discharge port, which is abnormal compared to the case where the second discharge port is provided near the first discharge port. Even when combustion of the gas generating agent by operation is started from the holder side, gas can be released in a short time from the time of abnormal operation. Therefore, a safer gas generator can be obtained.

It is the schematic of the cylinder type gas generator in 1st Embodiment of this invention. It is the schematic which shows the modification of the cylinder type gas generator in 1st Embodiment of this invention. It is the schematic of the cylinder type gas generator in 2nd Embodiment of this invention.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. In addition, 1st Embodiment shown below illustrates the case where this invention is applied to what is called a cylinder type gas generator suitably integrated in a side airbag apparatus etc.

  FIG. 1 is a schematic view of a cylinder type gas generator in a first embodiment of the present invention. Below, with reference to these FIG. 1, the external appearance structure and internal structure of the cylinder type gas generator 100 in 1st Embodiment are demonstrated.

  In FIG. 1, a cylinder type gas generator 100 according to the first embodiment of the present invention has a long and substantially cylindrical outer shape, and includes a housing 10 and a holder 20. The housing 10 is formed of a long cylindrical member having an opening at least at one end in the axial direction, and includes a cylindrical portion 11 and a closing portion 12. The holder 20 is fixed to the housing 10 so as to close the open end of the housing 10. The holder 20 is formed of a cylindrical member having a through-hole 21 extending in the same direction as the axial direction of the housing 10. The holder 20 includes an annular groove 22 for caulking and fixing, which will be described later, at a predetermined position on the outer peripheral surface of the housing 10. A caulking portion 23 is provided at an end portion facing the internal space. The annular groove portion 22 for caulking and fixing is formed in an annular shape on the outer peripheral surface of the holder 20 so as to extend in the circumferential direction. The caulking portion 23 is a portion for fixing an igniter 30 described later.

  The housing 10 and the holder 20 are connected and fixed by caulking. Specifically, the cylindrical portion 11 of the housing 10 corresponding to the annular groove portion 22 provided on the outer peripheral surface of the holder 20 in the state where a part of the holder 20 is inserted into the opening end of the housing 10 is changed in diameter. The holder 20 is caulked and fixed to the housing 10 by reducing the diameter inward (caulking) and engaging with the annular groove 22. These caulking fixations are caulking fixings called eight-side caulking that uniformly reduce the diameter of the cylindrical portion 11 of the housing 10 toward the inside in the radial direction.

  Further, the housing 10 and the holder 20 may each be made of a metal member such as stainless steel, steel, an aluminum alloy, or a stainless alloy, or by pressing a rolled steel plate represented by SPCE. A metal press-molded product molded into a bottomed cylindrical shape, or a metal molded product molded into a bottomed cylindrical shape by closing one of the axial ends of an ERW pipe typified by STKM It may be configured. In particular, when the housing 10 is configured as a press-formed product of a rolled steel plate or a molded product of an electric resistance welded tube, the housing can be formed more inexpensively and easily, and the weight can be significantly reduced.

  As shown in FIG. 1, the cylinder type gas generator 100 includes a working gas generation chamber 13 and a filter chamber 14 in a space inside the housing 10. The working gas generation chamber 13 is located at a substantially central portion of the housing 10 in the axial direction, and an igniter 30 and a cylindrical member (blocking member) 33 described later are accommodated therein. The filter chamber 14 is located on the closed portion 12 side of the housing 10, and a filter 37 described later is accommodated therein.

  A plurality of first gas discharge ports 15 are provided in the cylindrical portion 11 in the vicinity of the opposite end portion of the housing 10 to which the holder 20 is attached (that is, the portion defining the filter chamber 14). The first gas discharge port 15 is a hole for discharging the gas generated inside the cylinder type gas generator 100 to the outside during normal operation. A plurality of the first gas discharge ports 15 are provided along the circumferential direction and the axial direction of the housing 10. Is provided.

  A second gas discharge port 16 is provided in the cylindrical portion 11 of the housing 10 near the filter chamber 14 that defines the working gas generation chamber 13. A plurality of the second gas discharge ports 16 are provided at equal intervals in the circumferential direction of the housing 10, and are closed from the inside of the housing 10 by a portion 33 c of the cylindrical member 33. Although not shown, the second gas discharge ports 16 are provided with at least one row of two or more second gas discharge ports at equal intervals in the circumferential direction of the housing 10. That is, even numbers or odd numbers may be provided at equal intervals in the circumferential direction of the housing 10. Only when the pressure inside the housing 10 suddenly increases for some reason (during abnormal operation), the portion 33c facing the second gas discharge port 16 is broken and the second gas discharge port 16 is opened. It has become. Thereby, the generated gas inside the housing 10 can be immediately discharged from the second gas discharge port 16 to the outside of the housing 10, and the pressure inside the housing 10 can be reduced. The opening condition of the second gas discharge port 16 can be set as appropriate by changing the hole diameter and the number of the second gas discharge ports 16, or the thickness, material, or strength of the cylindrical member 33 can be changed. Can be set as appropriate. For example, in the present embodiment, in order to make the end portion 33a on the filter 37 side of the tubular member 33 easier to break than the portion 33c, the diameter of the hole in the center of the filter 37 is set to the second gas. It is formed larger than the hole diameter of the discharge port 16. That is, as a method of controlling the opening condition (breaking pressure) of the second gas discharge port 16, if the hole diameter of the second gas discharge port 16 is small, the break pressure increases (if the hole diameter of the second gas discharge port 16 is large). When the thickness of the tubular member 33 is increased, the breaking pressure is increased (when the thickness of the tubular member 33 is decreased, the breaking pressure is decreased), and the tensile strength in the material of the tubular member 33 is increased. The breaking pressure increases (the breaking pressure decreases as the tensile strength of the tubular member 33 decreases). In particular, the hole diameter of the second gas discharge port 16 will be described in detail. Even when the hole shape of the second gas discharge port 16 is not circular, if the area of the hole of the second gas discharge port 16 is large, the breaking pressure becomes low ( When the area of the hole of the second gas discharge port 16 is small, the breaking pressure becomes high), and when the circumference around the hole of the second gas discharge port 16 is long, the breaking pressure becomes high (hole of the second gas discharge port 16). If the perimeter around is short, the breaking pressure will be low).

  The igniter 30 is igniting means located on the holder 20 side of the housing 10, is for generating a flame for burning a granular gas generating agent 36 described later, and has an igniter 31. Further, the igniter 30 is inserted into the penetrating portion 21 of the holder 20 and fixed by caulking. More specifically, the holder 20 has a caulking portion 23 at an end portion facing the space inside the housing 10, and the igniter 30 is inserted into the through portion 21 and fixed to the holder 20. The igniter 30 is sandwiched between the holders 20 by caulking the caulking portion 23 in a state where the caulking portion 23 is in contact. Thereby, the igniter 30 is fixed to the holder 20. Another suitable form is a known method in which the igniter 30 and the holder 20 are integrated by injection molding with a thermoplastic resin or the like.

The igniter 30 includes a base frame (not shown) through which the pair of terminal pins 32 are inserted and held, and a squib cup attached to the base frame, and the terminal pins of the base frame inserted into the squib cup. A resistor (bridge wire) (not shown) is attached so as to connect the tip of 32, and an igniting agent (not shown) is filled in the squib cup so as to surround or contact the resistor. Depending on the situation, the charge is also filled. 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. Generally, a composition composed of a metal powder / oxidizer represented by B / KNO ₃ or the like, a composition composed of titanium hydride / potassium perchlorate, or a composition composed of B / 5-aminotetrazole / potassium nitrate / molybdenum trioxide. A composition or the like is used. The squib cup is generally made of metal or plastic.

  When a collision is detected, a predetermined amount of current flows through the terminal pin 32 to the resistor in the igniter 30. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and the ignition charge starts to burn upon receiving this heat. The high-temperature flame generated by the combustion ruptures the squib cup in the igniter 30 containing the igniting agent. The time from when a current flows through the resistor until the igniter 30 is activated is 2 milliseconds or less when a nichrome wire is used for the resistor.

  The cylindrical member 33 has a bottomed cylindrical shape made up of a cup-shaped member (not shown) and a lid (not shown), and a gas generating agent 36 is accommodated therein. Further, the outer peripheral surface of the cylindrical member 33 is in contact with the inner peripheral surface of the housing 10 and closes the second gas discharge port 16. This cylindrical member 33 can be comprised with metal members, such as stainless steel, steel, an aluminum alloy, and a stainless alloy. The cylindrical member 33 is made of a material such as an aluminum thin film so that it easily breaks at least at the portion 33c when the pressure of the gas generated by the combustion of the gas generating agent 36 exceeds a predetermined pressure. It is used in consideration of strength, hardness, thickness and the like. Further, the relationship between the strength or altitude and thickness of the material of the tubular member 33 and the hole diameter of the second gas discharge port 16 so that the breaking pressure at the portion 33 c of the tubular member 33 is smaller than the breaking pressure of the housing 10. The housing 10 is made thinner than before in a safe range.

  The gas generating agent 36 is a gas generated by burning the igniting agent ignited by the igniter 30 or is ignited and burned by hot particles to generate gas. The gas generating agent 36 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. The oxidant was selected from basic nitrates such as basic copper nitrate, perchlorates such as ammonium perchlorate or potassium perchlorate, alkali metals, alkaline earth metals, transition metals, and ammonia. For example, nitrates containing cations are 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, a cellulose derivative such as hydroxypropylmethylcellulose, an organic binder such as a metal salt of carboxymethylcellulose 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 36 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 cylinder type gas generator is incorporated. For example, a shape in which the gas generation rate changes with time during combustion of the gas generating agent is selected. It is preferable to do. In addition to the shape of the gas generating agent 36, it is preferable to appropriately select the size or / and the filling amount of the molded body in consideration of the linear combustion rate, the pressure index, and the like.

  As the gas generating agent 36, it is particularly preferable to use a gas containing a guanidine compound as a fuel and a perchlorate as an oxidizing agent. If the gas generating agent 36 containing this guanidine-based compound and perchlorate is used, the problem of toxicity unlike the azide compound does not occur. In particular, by containing perchlorate in the gas generating agent 36 and accelerating the combustion of the gas generating agent 36, it is possible to inflate the air bag in a short time after the collision has been detected and exhaust the gas. preferable. In particular, it is more preferable that the gas generating agent 36 contains 3 to 15 percent by weight of perchlorate because the above effect is enhanced.

  As described above, the cylinder-type gas generator 100 according to the first embodiment has a configuration in which the gas generating agent 36 is sealed in the cylindrical member 33, and thus the gas generating agent 36 is sealed in the cylindrical member 33 in advance. As a result, the assembly work of the cylinder type gas generator 100 is facilitated, and the number of parts can be reduced and the configuration can be simplified.

  The filter chamber 14 accommodates the filter 37 as described above, and communicates with the outside through the first gas discharge port 15 provided in the cylindrical portion 11 of the housing 10. The filter 37 is formed of a cylindrical member having a hollow portion extending in the same direction as the axial direction of the housing 10, and the end surface on the side of the working gas generation chamber 13 in the axial direction is in contact with the cylindrical member 33. The end surface is in contact with the closing portion 12 of the housing 10. Further, the outer peripheral surface of the filter 37 is in contact with the inner peripheral surface of the tubular portion 11 of the housing 10. If the filter 37 made of such a cylindrical member is used, the flow resistance of the gas flowing through the filter chamber 14 during operation of the cylinder-type gas generator 100 can be kept low, and an efficient gas flow can be realized. It becomes. In addition, when the gas generated in the working gas generation chamber 13 passes through the filter 37, it functions as a cooling means for cooling the gas by taking away the high-temperature heat of the gas, and the slag contained in the gas It also functions as a removing means for removing the like.

  As the filter 37, for example, a wire or netting material made of a metal such as stainless steel or steel, a material wound by pressing, a material wound with a perforated metal plate, or the like is used. Specifically, a knitted wire mesh or a plain weave wire mesh, an assembly of crimped metal wires, and the like are used. The perforated metal plate may be, for example, expanded metal that has been cut into a zigzag pattern on the metal plate and expanded to form a hole or processed into a mesh shape, or a hole is formed in the metal plate and In addition, a hook metal or the like obtained by flattening the burr by crushing the burr generated at the periphery of the hole is used. In this case, the size or shape of the hole to be formed can be appropriately changed as necessary, and holes of different sizes or shapes may be included on the same metal plate. As the metal plate, for example, a steel plate (mild steel) or a stainless steel plate may be preferably used, or a plate made of aluminum, copper, titanium, nickel, or an alloy thereof may be used. A filter formed by winding a metal wire or netting material into a cylindrical shape and sintering or compacting it in this way will contain voids inside, allowing the above-described gas cooling. In addition, it is possible to remove slag contained in the gas.

  A female connector is attached to the end of the cylinder type gas generator 100 on the side where the holder 20 is disposed. This female connector is a part to which a male connector of a harness for transmitting a signal from a collision detection means provided separately from the cylinder type gas generator 100 is connected. A shorting clip is attached to the female connector as necessary. The shorting clip is attached to prevent the cylinder type gas generator 100 from malfunctioning due to electrostatic discharge or the like when the cylinder type gas generator 100 is transported, and is attached to the airbag device. In the stage, the male connector of the harness is inserted into the female connector, so that the contact with the terminal pin 32 is released.

  Next, the operation | movement at the time of the action | operation of the cylinder type gas generator 100 is demonstrated. When a vehicle equipped with an airbag device incorporating the cylinder-type gas generator 100 according to the first embodiment collides, the collision is detected by a collision detection unit provided separately in the vehicle, and ignition is performed based on this. The device 30 is activated. When the igniter 30 is activated, the pressure in the igniter 31 increases due to combustion of the igniting agent, whereby the igniter 31 is ruptured and the flame flows out of the igniter 31. By the combustion of this ignition powder, the above-described flame reaches the cylindrical member 33. The flame that has reached the cylindrical member 33 melts the cylindrical member 33 and opens or divides the end portion 33b of the cylindrical member 33 on the holder 20 side, whereby the flame reaches the gas generating agent 36.

  The gas generating agent 36 is ignited and burned by the flame flowing into the cylindrical member 33, and a large amount of gas is generated. Due to the combustion of the gas generating agent 36, the pressure in the working gas generating chamber 13 is increased, and the end portion 33a on the filter 37 side of the cylindrical member 33 is destroyed. At this time, since the diameter of the hole at the center of the filter 37 is larger than the hole diameter of the second gas discharge port 16, the end portion 33a on the filter 37 side of the tubular member 33 is destroyed, but the portion 33c Will not break. The gas generated in this manner flows into the filter chamber 14, is cooled to a predetermined temperature via the filter 37, and is discharged from the first gas discharge port 15 to the outside of the cylinder type gas generator 100. Is done. The gas discharged from the first gas discharge port 15 is guided to the inside of the airbag to inflate and deploy the airbag.

  Further, when the pressure inside the housing 10 increases more rapidly than during normal operation (for example, during an abnormal operation) for some reason (for example, an external fire), the portion 33c is broken and the second gas discharge port 16 is opened. As a result, the generated gas inside the housing 10 is discharged from the first gas discharge port 15 through the filter 37 by opening the end portion 33a of the cylindrical member 33 on the filter 37 side, and The two gas discharge ports 16 are also discharged to the outside. Therefore, the total area of the gas discharge ports provided in the housing is larger than that in the normal operation, so that the gas discharge amount is increased, and the pressure inside the housing 10 is immediately decreased, and the housing 10 is broken. Can be avoided. Further, since the plurality of second gas discharge ports 16 are provided at equal intervals in the circumferential direction of the housing 10, thrust can be canceled even when a large amount of gas is discharged from the second gas discharge ports 16. It is possible to prevent the generator 100 from flying. Further, in the gas generator 100, each part is formed so as to satisfy the relationship of the maximum internal pressure of the gas generator when operating at 120 ° C. <the breaking pressure of the tubular member (closing member) 33 <the breaking pressure of the housing 10. doing. Specifically, for example, when the internal maximum pressure inside the gas generator at 120 ° C. in the gas generator of the present invention is 30 MPa, the pressure at which the portion 33C of the cylindrical member 33 breaks is 50 MPa, Each part can be formed so that the breaking pressure is 100 MPa.

  As described above, in the cylinder type gas generator 100 according to the first embodiment, even when the pressure inside the housing 10 suddenly increases for some reason, the housing 10 is prevented from being broken and scattered. Since the pressure inside the housing 10 can be efficiently reduced, the operation of the cylinder type gas generator 100 can be stably controlled.

  Further, since the cylindrical member 33 closes the second gas discharge port 16 in the working gas generation chamber 13 and seals the gas generating agent 36 inside, the number of parts is small, and the second gas discharge port It can be set as the cylinder type gas generator 100 which is easy to manufacture rather than sticking a sealing member on the inner wall of 16.

  In the first embodiment, the case where the second gas discharge port 16 is provided in the cylindrical portion 11 of the housing 10 near the filter chamber 14 that defines the working gas generation chamber 13 will be described as an example. Although the position where the second gas discharge port 16 is provided is not limited to this, for example, as shown in FIG. 2, the second gas discharge port 116 is close to the portion of the igniter 130 that defines the working gas generation chamber 113. The cylindrical portion 111 of the housing 110 may be provided. That is, the second gas discharge ports 116 are formed at equal intervals in the circumferential direction of the housing 110, and the portion 33c bursts only when the pressure inside the housing 110 suddenly increases for some reason, and the second gas discharge ports 116 are formed. When configured to open, an effect similar to the effect described in the first embodiment described above can be obtained. In particular, when the gas generating agent 136 near the igniter 130 in the working gas generation chamber 113 starts to burn during an abnormal operation, the generated gas is quickly released to the outside through the second gas discharge port 116. It is effective because it can be done. Regarding the part using the same number in the last two digits, except that the second gas discharge port 116 is provided in the cylindrical part 111 of the housing 110 near the igniter 130 that defines the working gas generation chamber 113. Since it is the same as that of the said 1st Embodiment, description is abbreviate | omitted.

Second Embodiment
FIG. 3 is a schematic view of a cylinder type gas generator in the second embodiment of the present invention. Hereinafter, with reference to FIG. 3, the structure of the cylinder type gas generator 300 in 2nd Embodiment is demonstrated. Unless otherwise indicated, the parts using the same numbers in the last two digits are the same as those in the first embodiment, and thus the description thereof is omitted.

  As shown in FIG. 3, the cylinder-type gas generator 300 in the embodiment of the present invention has a cylindrical member shape when compared with the cylinder-type gas generator 100 in the first embodiment of the present invention described above. It is different. Specifically, in the cylinder type gas generator 300 according to the present embodiment, the diameter of the cylindrical member 233 whose peripheral wall portion faces the second gas discharge port 216 provided in the cylindrical portion 211 of the housing 210. The diameter of the portion 233 d is formed to be smaller than the diameter of the main body portion 233 e of the cylindrical member 233 facing the igniter 230. In addition, the ring-shaped member 245 has an outer peripheral portion that contacts the inner side of the second gas discharge port 216 and closes the second gas discharge port 16, and an inner peripheral portion of the reduced diameter portion 233 d of the cylindrical member 233. It is provided so as to contact the outer peripheral surface.

  Here, the portion 245a of the ring-shaped member 245 that contacts the second gas discharge port 216 has a reduced diameter portion that faces the second gas discharge port 216 when the pressure inside the housing 210 suddenly increases for some reason. The second gas discharge port 216 is opened after the breakage of the portion 233c of 233d. As a result, the generated gas inside the housing 210 can be discharged from the second gas discharge port 216 to the outside of the housing 210, and the pressure inside the housing 210 can be reduced during abnormal operation. The opening conditions of the second gas discharge port 216 change the hole diameter and number of the second gas discharge ports 216, the thickness of the reduced diameter portion 233d corresponding to the second gas discharge port 216, the thickness of the ring-shaped member 245, and the like. Can be set as appropriate. In particular, the setting of the opening condition of the second gas discharge port 216 can be easily changed depending on the thickness of the ring-shaped member 245.

  Even when the cylinder type gas generator 300 according to the present embodiment described above is used, the same effects as those described in the first embodiment can be obtained.

  Thus, the above-described embodiment disclosed herein is illustrative in all respects and is 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. For example, in the second embodiment, similarly to the modification of the first embodiment, the second gas discharge port is disposed on the holder side of the working gas generation chamber and the ring-shaped member is fitted in the second embodiment. If the cylindrical member is rotated 180 ° and disposed in the housing so that the reduced diameter portion side becomes the holder side, and the second gas discharge port and the ring-shaped member abut, the first embodiment The same effects as those of the modified example can be obtained.

  Moreover, it is good also as a gas generator which stuck the sealing member from the inner side of the 2nd gas discharge port instead of the cylindrical member in the modification of 1st Embodiment and 1st Embodiment.

10, 110, 210 Housing 11, 111, 211 Tubular part 12, 112, 212 Closure part 13, 113, 213 Working gas generation chamber 14, 114, 214 Filter chamber 15, 215, 315 First gas discharge port 16, 116 216 Second gas discharge port 17, 117, 217 Plate member 20, 120, 220 Holder 21, 121, 221 Through part 22, 122, 222 Annular groove part 23, 123, 223 Caulking part 30, 130, 230 Igniter 31, 131, 231 Ignition parts 32, 132, 232 Terminal pins 33, 133, 233 Cylindrical members 33a, 33b, 133a, 133b, 233a, 233b Ends 33c, 133c, 233c, 245a Sites 36, 136, 236 Gas generating agent 37 137, 237 Filter 100, 200, 300 Cylinder type gas generation 233d reduced diameter portion 233e body portion 245 ring member

Claims (7)

A working gas generation chamber in which a working gas is generated by combustion of a gas generating agent contained therein, and a filter chamber in which a filter through which the working gas generated in the working gas generation chamber passes are housed. A long cylindrical housing contained in
It contains ignition powder, and is disposed so as to sandwich the working gas generation chamber together with the filter at one end in the axial direction of the housing, and can ignite and burn the gas generating agent in the working gas generation chamber Gas generating agent ignition means;
With
A plurality of first gas discharge ports for discharging the working gas that has passed through the filter to the outside are provided in a peripheral wall portion of a portion that defines the filter chamber of the housing,
The peripheral wall portion of the portion defining the working gas generation chamber of the housing is provided with a plurality of second gas discharge ports closed by a closing member,
The gas generator according to claim 1, wherein the closing member is broken at a portion in contact with the second gas discharge port when the internal pressure of the housing is higher than that during normal operation.   The gas generator according to claim 1, wherein a breaking pressure of the closing member is smaller than a breaking pressure of the housing. The gas generator according to claim 2, wherein the breaking pressure of the closing member satisfies the following relationship.
Maximum internal pressure of the gas generator during operation at 120 ° C. <rupture pressure of the closing member <break pressure of the housing   The gas generator according to any one of claims 1 to 3, wherein the plurality of second gas discharge ports are provided in at least one row at equal intervals in the circumferential direction of the housing. The closing member is a part of a bottomed cylindrical member having a cylindrical portion formed so as to close at least the second gas discharge port in the working gas generation chamber;
The gas generator according to any one of claims 1 to 4, wherein the bottomed cylindrical member has the gas generating agent sealed therein. A first cylindrical portion and a second cylindrical portion having a peripheral wall portion having a diameter smaller than that of the first cylindrical portion and facing the second gas discharge port, and the gas generating agent is contained therein. A sealed bottomed cylindrical member is provided,
The gas generator according to any one of claims 1 to 4, wherein the closing member is a ring-shaped member fitted into the second cylindrical portion. The gas generator according to any one of claims 1 to 6, wherein the second gas discharge port is formed closer to the gas generating agent ignition means than the center of the working gas generation chamber. .

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