Gas generator and air bag module assembly

Abstract

To provide a technology which can efficiently suppress a rise in temperature of a housing after actuating a gas generator.SOLUTION: A gas generator comprises a temperature rise suppression member provided in contact with the outer surface of a housing so as to cover the outer surface, the temperature rise suppression member including an endothermic agent which absorbs the heat of the housing by the occurrence of a chemical change or a state change by the heat of the housing upon a rise in temperature of the housing due to the combustion of a gas generation agent, and a binder agent which coexists with the endothermic agent so that the temperature rise suppression member may have flexibility.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a gas generator and airbag module assembly. [Background technology]

[0002] A gas generator that contains a gas generating agent in a housing, burns the gas generating agent by activation of an ignition device to generate gas, and releases the gas to the outside of the housing has been widely known. This type of gas generator is used, for example, to supply gas to an airbag or a seat belt retractor of an automobile.

[0003] When a gas generator is activated, the surface of the housing becomes hot due to the conduction of heat from the combustion of the gas generating agent. For example, when the gas generator is activated to inflate and deploy an airbag, if the airbag comes into contact with the hot housing, there is a concern that the airbag may melt or be otherwise thermally affected by components disposed around the housing. In relation to this, a gas generator has been disclosed in which a heat insulating member is provided on the surface of the housing to suppress an increase in the surface temperature of the housing (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-326553 A Summary of the Invention [Problem to be solved by the invention]

[0005] In order to more efficiently suppress the temperature rise in the housing after activation of the gas generator, it is important to provide a member for suppressing the temperature rise in the housing with good adhesion.

[0006] The technology of the present disclosure has been made in consideration of the above-mentioned circumstances, and has an object to provide a technology capable of more efficiently suppressing a rise in temperature of a housing after activation of a gas generator. [Means for solving the problem]

[0007] (Aspect 1) In order to solve the above problems, a gas generator according to one aspect of the present disclosure employs the following configuration. That is, the gas generator according to the present disclosure is a gas generator including: a gas generating agent that generates gas by combustion, a metal housing that accommodates the gas generating agent therein and has a gas exhaust hole formed therein for exhausting the gas generated by combustion of the gas generating agent to the outside, an ignition device that ignites the gas generating agent by activation, and a temperature rise suppression member that is provided in contact with the outer surface of the housing so as to cover at least a portion of the outer surface of the housing, the temperature rise suppression member including a heat absorption agent that absorbs heat of the housing by undergoing a chemical change or state change due to heat of the housing when the temperature of the housing rises due to combustion of the gas generating agent, and a binder agent that coexists with the heat absorption agent so that the temperature rise suppression member has flexibility.

[0008] (Aspect 2) In the above-mentioned embodiment 1, the binder may be mixed with the heat absorbing agent.

[0009] (Aspect 3) In the above-mentioned aspect 1 or 2, the heat absorbing agent may include at least one selected from the group consisting of fatty acid polycarbonate, magnesium carbonate, fumaric acid, and terephthalic acid. good.

[0010] (Aspect 4) In any one of the above aspects 1 to 3, the binder agent may include a compound having a hydroxyl group or a carbonyl group.

[0011] (Aspect 5) In any of the above aspects 1 to 4, the content of the heat absorbing agent in the temperature rise suppression member may be 70% or more and 95% or less, and the content of the binder agent in the temperature rise suppression member may be 5% or more and 30% or less.

[0012] (Aspect 6) In any of the above aspects 1 to 5, the housing has a cylindrical peripheral wall portion in which the gas exhaust hole is formed, a first blocking portion blocking one end of the peripheral wall portion, and a second blocking portion blocking the other end of the peripheral wall portion, the gas exhaust hole is formed at a position such that the distance between the gas exhaust hole and the first blocking portion in the axial direction of the housing is shorter than the distance between the gas exhaust hole and the second blocking portion, and the temperature rise suppression member may be provided on an outer surface of the first blocking portion.

[0013] (Aspect 7) In any one of the above aspects 1 to 6, the housing may have a cylindrical peripheral wall portion in which the gas exhaust hole is formed, and the temperature rise suppression member may be provided on an outer surface of the peripheral wall portion.

[0014] (Aspect 8) In any one of the above-mentioned aspects 1 to 7, a portion of the outer surface of the housing that comes into contact with the temperature rise suppressing member may be formed to have an uneven shape.

[0015] (Aspect 9) In any of the above aspects 1 to 8, the device may further include a label sheet displaying predetermined information, and the label sheet may be attached to the temperature rise suppression member such that the temperature rise suppression member is interposed between the label sheet and the housing.

[0016] (Aspect 10) The technology according to the present disclosure can also be specified as an airbag module assembly including a gas generator. That is, one aspect of the present disclosure is an airbag module assembly including the gas generator of the above-mentioned aspect 6 and an airbag arranged in a folded state and inflated and deployed by the gas discharged from the gas discharge hole, and the gas generator may be arranged so that the first blocking portion faces the airbag in the folded state.

[0017] (Aspect 11) An airbag module assembly according to one embodiment of the present disclosure includes the gas generator of embodiment 7 above, and an airbag arranged in a folded state and inflated and deployed by the gas discharged from the gas discharge hole, wherein the gas generator is arranged so that the peripheral wall portion faces the airbag in the folded state, and the temperature rise suppression member may be provided on an outer surface of the peripheral wall portion at a portion facing the airbag. Effect of the Invention

[0018] According to the present disclosure, it is possible to more efficiently suppress the temperature rise of the housing after the gas generator is activated. . [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view showing a state before activation of an airbag module assembly including a gas generator according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing the gas generator according to the first embodiment in a state prior to activation. [Diagram 3] FIG. 3 is a partial enlarged view of a gas generator according to a first modification of the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a state before activation of an airbag module assembly including a gas generator according to a second modification of the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing a state before activation of a gas generator according to a second modification of the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a state before activation of an airbag module assembly including a gas generator according to the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a state before activation of the gas generator according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the embodiment described below, an aspect in which the technology according to the present disclosure is applied to a gas generator (inflator) for an airbag will be described. However, the use of the technology according to the present disclosure is not limited thereto, and it may be applied to a gas generator for a seat belt retractor, for example. Note that each configuration and their combinations in each embodiment are merely examples, and addition, omission, substitution, and other modifications of the configurations are possible as appropriate within the scope of the gist of the present invention. The present disclosure is not limited by the embodiments, but is limited only by the claims.

[0021] <Embodiment 1> FIG. 1 is a cross-sectional view showing a state before activation of an airbag module assembly 1000 including a gas generator for an airbag (hereinafter, simply referred to as a gas generator) 100 according to the first embodiment. FIG. 2 is a cross-sectional view showing a state before activation of the gas generator 100 according to the first embodiment. In FIGS. 1 and 2, a cross section along a central axis A1 of a housing indicated by reference numeral 1 is shown. Here, a direction along the central axis A1 of the housing 1 (axial direction) is defined as a vertical direction of the gas generator 100, an upper shell side indicated by reference numeral 2 in FIG. 2 (i.e., the upper side in FIG. 2) is the upper side of the gas generator 100, and a lower shell side indicated by reference numeral 3 in FIG. 2 (i.e., the lower side in FIG. 2) is the lower side of the gas generator 100. In this specification, activation of an igniter included in an ignition device provided in a gas generator may be expressed as "the ignition device is activated", "the gas generator is activated", or "the airbag module assembly is activated" for convenience.

[0022] [Overall configuration] As shown in FIG. 1, the airbag module assembly 1000 includes a gas generator 100, an airbag 200, and a module case 300 that houses them. The airbag module assembly 1000 is, for example, an airbag device for protecting a frontal collision (a so-called front airbag device) that is mounted on a vehicle and protects an occupant from impact by inflating and deploying an airbag 200 at the time of a frontal collision of the vehicle. However, the airbag module assembly according to the present disclosure is not limited to a front airbag device. The airbag module assembly may be, for example, an airbag device for protecting a side collision (a so-called side airbag device) that protects an occupant from impact by inflating and deploying an airbag at the time of a side collision of the vehicle. In addition, the airbag module assembly 1000 according to the present embodiment is, for example, installed in the driver's seat (specifically, the steering wheel) of a vehicle, but the airbag module assembly according to the present disclosure may be installed, for example, on the dashboard of the passenger seat or other locations.

[0023] The gas generator 100 is a supply source of gas for inflating the airbag 200. The gas generator 100 is configured to be activated, for example, when a sensor (not shown) of the vehicle detects an impact, and to release gas to the outside. The gas generator 100 will be described in detail later.

[0024] The airbag 200 is a bag that is inflated by the supply of gas from the gas generator 100. The airbag 200 is made of, for example, polyamide, and is housed in a module case 300 in a folded state before the gas generator 100 is activated, as shown in FIG.

[0025] The module case 300 is a box that houses the gas generator 100 and the airbag 200. The module case 300 includes an airbag cover 400 and a back plate 500. The airbag cover 400 includes a cylindrical tube wall portion 401 that forms a side surface of the module case 300, and a front portion 402 that closes one end of the tube wall portion 401 and forms the front surface of the module case 300. The airbag cover 400 is formed so as to be able to be combined with, for example, a steering wheel of a vehicle. The back plate 500 includes a cylindrical tube wall portion 501 that is fixed to the tube wall portion 401 of the airbag cover 400 to form the side surface of the module case 300 together with the tube wall portion 401, and a back portion 502 that closes one end of the tube wall portion 501 and forms the back surface of the module case 300. A mounting hole 502a for mounting the gas generator 100 is formed in the back portion 502. The airbag 200 is connected to the gas generator 100, and is disposed in a folded state between the gas generator 100 and the front part 402 of the module case 300.

[0026] The airbag module assembly 1000 is installed in the vehicle so that the front part 402 of the airbag cover 400 faces the occupant (the driver in this example) who is the object of protection of the airbag 200. When the gas generator 100 is activated, the front part 402 is ruptured by the pressure caused by the expansion of the airbag 200, and the airbag 200 jumps out of the module case 300 and deploys in front of the occupant. This protects the occupant from impact.

[0027] [Gas generator] As shown in FIG. 2, the gas generator 100 according to the first embodiment is formed in a short cylindrical shape (disc shape) and includes an ignition device 4, an inner cylinder member 5, a filter 6, a first gas generating agent 110, a second gas generating agent 120, a metal housing 1 that accommodates these, and a temperature rise suppression member 7 provided on the outer surface of the housing 1. The gas generator 100 is configured as a so-called single-type gas generator that includes only one ignition device. The gas generator 100 is also configured as a so-called pyrotype gas generator that uses only a gas generating agent as a gas source. However, the gas generator according to the present disclosure is not limited to the above. The gas generator according to the present disclosure may include a plurality of ignition devices, or may be configured as a so-called hybrid type gas generator that uses a gas generating agent and pressurized gas as a gas source.

[0028] The gas generator 100 is configured to combust the first gas generating agent 110 and the second gas generating agent 120 by activating the igniter 41 included in the ignition device 4, and to discharge the combustion gas, which is the combustion product, from the gas discharge hole 11 formed in the housing 1. Each component of the gas generator 100 will be described below.

[0029] [housing] The housing 1 is formed into a short cylindrical shape with both axial ends closed by joining an upper shell 2 and a lower shell 3, each of which is made of metal and formed into a substantially cylindrical shape with a bottom, with their open ends facing each other. The housing 1 is made of metal. The metal material forming the housing 1 is not particularly limited, but stainless steel can be given as an example. The internal space of the housing 1 forms a combustion chamber 10, in which an ignition device 4, an inner cylinder member 5, a filter 6, a first gas generating agent 110, and a second gas generating agent 120 are arranged.

[0030] The upper shell 2 has a cylindrical upper peripheral wall portion 21 and a top plate portion 22 that closes the upper end of the upper peripheral wall portion 21, and together they form an internal space. The lower end of the upper peripheral wall portion 21 forms an opening of the upper shell 2. A flange-shaped joint portion 23 extending radially outward is connected to the lower end of the upper peripheral wall portion 21. The lower shell 3 has a cylindrical lower peripheral wall portion 31 and a bottom plate portion 32 that closes the lower end of the lower peripheral wall portion 31 and to which the ignition device 4 is fixed, and together they form an internal space. The bottom plate portion 32 has an attachment hole 32a for attaching the ignition device 4. A flange-shaped joint portion 33 extending radially outward is connected to the upper end of the lower peripheral wall portion 31.

[0031] The upper shell 2 and the lower shell 3 can be formed by, for example, pressing stainless steel. The joint 23 of the upper shell 2 and the joint 33 of the lower shell 3 are overlapped and joined by laser welding or the like to form a short cylindrical housing 1 with both axial ends closed. The upper peripheral wall 21 of the upper shell 2 and the lower peripheral wall 31 of the lower shell 3 form a cylindrical peripheral wall 12 that connects the top plate 22 and the bottom plate 32. That is, the housing 1 is configured to include the cylindrical peripheral wall 12, the top plate 22 that closes one end of the peripheral wall 12, and the bottom plate 32 that closes the other end of the peripheral wall 12 and has the ignition device 4 attached thereto. The top plate 22, the bottom plate 32, and the peripheral wall 12 define a combustion chamber 10. The central axis of the peripheral wall 12 constitutes a central axis A1 of the housing 1. The top plate 22 is an example of a "first closing portion" according to the present disclosure. The bottom plate portion 32 is an example of a "second closing portion" according to the present disclosure.

[0032] 2, a plurality of gas exhaust holes 11 that communicate between the combustion chamber 10 and the external space of the housing 1 are formed in the peripheral wall portion 12 (more specifically, the upper peripheral wall portion 21 of the upper shell 2) in a row along the circumferential direction. Before the ignition device 4 is activated, the gas exhaust holes 11 are closed by a sealing tape (not shown).

[0033] Also, as shown in FIG. 2, the outer surface of the housing 1, specifically, the surface on the side opposite to the surface that defines the internal space (combustion chamber 10) of the housing 1 is denoted by reference sign S1. The outer surface S1 is the surface facing the outside of the gas generator 100. Further, among the outer surface S1, the surface of the peripheral wall portion 12 is defined as the outer surface S12, the surface of the top plate portion 22 is defined as the outer surface S22, and the surface of the bottom plate portion 32 is defined as the outer surface S32.

[0034] As shown in FIG. 1, the gas generator 100 is attached to the back plate 500 by fixing the flange portions (joint portions 23, 33) of the housing 1 to the back surface portion 502 in a state where the gas discharge hole 11 and the top plate portion 22 of the housing 1 are inserted into the module case 300 from the mounting hole 502a of the module case 300. In the airbag module assembly 1000, the gas discharge hole 11 and the top plate portion 22 of the housing 1 are located inside the module case 300, and the bottom plate portion 32 is located outside the module case 300. The gas generator 100 is arranged such that the top plate portion 22 of the housing 1 faces the airbag 200.

[0035] Here, as shown in FIG. 2, the distance between the gas discharge hole 11 and the top plate portion 22 in the axial direction (vertical direction in this example) of the housing 1 is denoted as d1, and the distance between the gas discharge hole 11 and the bottom plate portion 32 in the axial direction of the housing 1 is denoted as d2. Here, the gas discharge hole 11 is formed at a position such that d1 is shorter than d2 in the axial direction of the housing 1. That is, the gas generator 100 according to the present embodiment is configured such that d1 < d2. Therefore, the gas discharge hole 11 is formed at a position closer to the top plate portion 22 than the bottom plate portion 32. In the gas generator 100, the gas discharge hole 11 is formed at a position closer to the top plate portion 22, which is the side where the airbag 200 is disposed, between the top plate portion 22 and the bottom plate portion 32 so as to easily supply gas to the airbag 200.

[0036] [Ignition device] As shown in FIG. 2, the ignition device 4 includes an igniter 41, a collar 42, and a resin part 43, and is attached to the bottom plate part 32 of the lower shell 3. The igniter 41 has a metal cup body 411 in which an ignition charge is accommodated, and a pair of current-carrying pins 412, 412 for receiving a current supply from the outside. The igniter 41 is activated by an ignition current supplied to the pair of current-carrying pins 412, 412 to burn the ignition charge and release the combustion product to the outside of the cup body 411. The collar 42 is a metal member that supports the igniter 41. The collar 42 is formed in a cylindrical shape, and is fixed by welding or the like in a state in which it is pressed into a mounting hole 32a formed in the bottom plate part 32. The resin part 43 is a resin member that is interposed between the igniter 41 and the collar 42 to fix the igniter 41 to the collar 42. The resin part 43 covers the lower part of the igniter 41 and engages with the collar 42, thereby fixing the igniter 41 to the collar 42 such that at least a part of the cup body 411 is exposed from the resin part 43. However, the entire cup body 411 may be overmolded by the resin part 43. That is, the entire cup body 411 may be covered with resin. The resin part 43 forms a connector insertion space inside the collar 42 into which a connector (not shown) that supplies power from an external power source to the pair of energizing pins 412, 412 can be inserted. The resin part 43 covers and holds a part of the pair of energizing pins 412, 412 such that the lower ends of the pair of energizing pins 412, 412 are exposed to the connector insertion space. The resin part 43 maintains insulation between the pair of energizing pins 412, 412. The fixing of the igniter 41 to the collar 42 and the relationship between the collar 42 and the bottom plate portion 32 are not limited to those shown in FIG. 2, and known techniques can be used.

[0037] [Inner cylinder material] The inner cylinder member 5 is a cylindrical metal member extending from the bottom plate portion 32 toward the top plate portion 22 so as to surround the ignition device 4. The inner cylinder member 5 is formed in a cylindrical shape with both ends open. In the combustion chamber 10, between the inner cylinder member 5 and the ignition device 4, a transfer chamber 51 is formed, which is a space in which the first gas generating agent 110 is accommodated. The first gas generating agent 110 is burned by the activation of the igniter 41 to generate combustion gas and the like. The inner cylinder member 5 is also formed with a plurality of communication holes 52 that communicate its internal space (i.e., the transfer chamber 51) with the external space. The communication holes 52 are closed by a sealing tape (not shown) before the ignition device 4 is activated.

[0038] [filter] The filter 6 is a cylindrical member formed of a metal material, extending in the vertical direction, and has a plurality of holes. As shown in Fig. 2, the filter 6 is disposed in the combustion chamber 10 so as to surround the second gas generating agent 120 and to position the gas discharge hole 11 on the outer side of the filter 6 in the radial direction. In other words, the filter 6 is disposed between the second gas generating agent 120 and the gas discharge hole 11 so as to surround the second gas generating agent 120. The filter 6 has two axial end faces, one of which (an upper end face indicated by reference numeral 61) is supported by abutting against the top plate portion 22 of the upper shell 2, and the other end face (a lower end face indicated by reference numeral 62) is supported by abutting against the bottom plate portion 32 of the lower shell 3.

[0039] Since a plurality of holes are formed in this filter 6, the combustion gas of the second gas generating agent 120 arranged in the combustion chamber 10 can pass through the filter 6. The filter 6 has a function as a coolant, and cools the combustion gas by removing heat from the combustion gas when the combustion gas passes through the filter 6. In addition to the above-mentioned function of cooling the combustion gas, the filter 6 also has a function of filtering the combustion gas by collecting combustion residues contained in the combustion gas.

[0040] [Gas generator] The first gas generating agent 110 is a so-called transfer charge that ignites the second gas generating agent by burning when the ignition device 4 is activated. As the first gas generating agent 110, in addition to known black powder, a gas generating agent having good ignition properties and a higher combustion temperature than the second gas generating agent 120 can be used. The combustion temperature of the first gas generating agent 110 can be set in the range of 1700 to 3000°C. As such a first gas generating agent 110, for example, a known agent containing nitroguanidine (34% by weight) and strontium nitrate (56% by weight) can be used. In addition, the first gas generating agent 110 can be in various shapes, such as granular, pellet, cylindrical, and disk shapes.

[0041] A gas generating agent having a relatively low combustion temperature can be used for the second gas generating agent 120. The combustion temperature of the second gas generating agent 120 can be set in the range of 1000 to 1700°C. As such a second gas generating agent 120, for example, a known agent containing guanidine nitrate (41% by weight), basic copper nitrate (49% by weight), a binder, and an additive can be used. In addition, the second gas generating agent 120 can be in various shapes, such as granular, pellet, cylindrical, and disk shapes.

[0042] [Temperature rise suppression material] The temperature rise suppression member 7 is a member that absorbs heat from the housing 1 when the temperature of the housing 1 rises due to the combustion of the gas generating agent, thereby suppressing a further rise in temperature of the housing 1. As shown in FIG. 2, the temperature rise suppression member 7 is provided so as to cover a part of the outer surface S1 of the housing 1. In this embodiment, the temperature rise suppression member 7 is provided in contact with only the outer surface S22 of the top plate portion 22 that faces the airbag 200 in the airbag module assembly 1000, among the outer surface S1. The outer surface S22 of the top plate portion 22 is covered with the film-like temperature rise suppression member 7. The temperature rise suppression member 7 according to this embodiment is in contact with the outer surface S1 of the housing 1 (the outer surface S22 in this example) so that the heat of the housing 1 is easily transferred to the temperature rise suppression member 7. In the entire region of the top plate portion 22, which is the portion of the housing 1 where the temperature rise suppression member 7 is arranged, the temperature rise suppression member 7 is in close contact with the outer surface S22. When the temperature of the housing 1 rises due to the combustion of the gas generating agent, the heat of the housing 1 is transferred to the temperature rise suppression member 7 by thermal conduction. Note that the technology according to the present disclosure does not limit the location of the temperature rise suppression member on the housing. The temperature rise suppression member may be provided in contact with the outer surface of the housing so as to cover at least a portion of the outer surface of the housing. For example, the temperature rise suppression member may be provided in contact with the entire area of ​​the outer surface of the housing.

[0043] The temperature rise suppression member 7 contains a heat absorbing agent that exhibits a heat absorbing effect and a binder agent that coexists with the heat absorbing agent so as to give flexibility to the temperature rise suppression member 7, and is preferably formed by mixing these.

[0044] When the temperature of the housing 1 rises to a predetermined temperature due to the combustion of the gas generating agent, the endothermic agent absorbs the heat of the housing 1 by causing a chemical change or a state change using the heat of the housing 1. Here, the predetermined temperature is set to a temperature higher than the temperature of the housing 1 before the gas generator 100 is activated and lower than the maximum temperature of the housing 1 that is assumed when the gas generating agent is burned when the temperature rise suppression member 7 is not provided in the housing 1. The predetermined temperature is not particularly limited, but for example, if the maximum temperature when the temperature of the housing 1 rises due to the combustion of the gas generating agent in a state in which the temperature rise suppression member 7 is not provided is 300°C, the predetermined temperature is set to less than 300°C. In other words, the endothermic agent suppresses the temperature of the housing 1 from rising to the above-mentioned maximum temperature by causing a chemical change or a state change accompanied by an endothermic effect at a temperature lower than the maximum temperature of the housing 1 that is assumed when the gas generating agent is burned when the temperature rise suppression member 7 is not provided in the housing 1. Also, the chemical change caused by the endothermic agent due to the heat of the housing 1 here means a change to a different compound. The change in state of the heat absorbing agent caused by the heat of the housing 1 means a physical change in shape. The type of chemical change or state change caused by the endothermic agent due to heat is not particularly limited, but an example of a chemical change is thermal decomposition of a compound, and an example of a state change is sublimation from a solid to a gas. In other words, the endothermic agent may absorb the heat of the housing 1 by thermally decomposing due to the heat of the housing 1, or may absorb the heat of the housing 1 by sublimating from a solid to a gas due to the heat of the housing 1. The endothermic agent cools the housing 1 by removing the thermal energy required for these state changes or chemical changes from the housing 1.

[0045] The endothermic agent may be non-combustible. The endothermic agent may be composed of at least one selected from the group consisting of fatty acid polycarbonate and magnesium carbonate as a compound that decomposes at a temperature lower than 300°C. The endothermic agent may be composed of at least one selected from the group consisting of p-dichlorobenzene, DL-camphor, naphthalene, fumaric acid, and terephthalic acid as a substance that exhibits endothermic properties by sublimation. The endothermic agent may include a combination of the above compounds. However, the material of the endothermic agent according to the present disclosure is not limited to the above.

[0046] The binder is used together with the heat absorbing agent to provide flexibility to the temperature rise suppression member 7. The binder may be present together with the heat absorbing agent in the temperature rise suppression member 7, and the arrangement of the binder is not particularly limited, but it is preferable that the binder is mixed with the heat absorbing agent. The binder provides flexibility to the temperature rise suppression member 7, thereby improving the adhesion of the temperature rise suppression member 7 to the housing 1, and the temperature rise suppression member 7 is less likely to peel off from the housing 1. In this sense, the heat absorbing agent and the binder do not need to be mixed together in the temperature rise suppression member 7. For example, the binder may be arranged separately from the heat absorbing agent without being mixed therewith, and may be interposed in a layer between the housing and the heat absorbing agent. However, from the viewpoint of improving the flexibility of the temperature rise suppression member 7, it is more preferable that the binder is mixed with the heat absorbing agent and the two are integrated. Furthermore, the temperature rise suppression member 7 is provided with flexibility, which prevents the temperature rise suppression member 7 attached to the housing 1 from being damaged (cracks, etc.) due to deformation of the housing 1 or impact from the outside.

[0047] It is preferable to use a binder agent that does not generate unnecessary gases (carbon monoxide, nitrogen oxide, etc.) even when decomposed by heat during operation of the gas generator 100. In this regard, the binder agent is preferably configured to include, for example, a compound having a hydroxyl group or a carbonyl group as a functional group in the molecule, and is more preferably used by being mixed with the heat absorbing agent. Furthermore, by using a compound having a composition including these functional groups as the binder agent, the flexibility of the temperature rise suppression member 7 is suitably improved. Furthermore, even if gas is generated from the binder agent heated by heat transfer from the housing 1, for example, the gas can be rendered harmless.

[0048] The binder may be, for example, at least one selected from the group consisting of butadiene rubber, silicon rubber, polyvinyl alcohol, ethylene vinyl alcohol, styrene butadiene rubber, natural rubber, chloroprene rubber, isoprene rubber, acrylic rubber, alkyl acetalized polyvinyl alcohol, and polycarboxylic acid copolymer. The binder may include a combination of the above compounds. For example, by using alkyl acetalized polyvinyl alcohol or polycarboxylic acid copolymer as a binder in a state mixed with a heat absorbing agent, the temperature rise suppression member 7 applied to the housing 1 is unlikely to crack even when bent, and the temperature rise suppression member 7 is unlikely to peel off from the housing 1. However, the material of the binder according to the present disclosure is not limited to the above.

[0049] Here, it is preferable that the content ratio of the heat absorbing agent in the temperature rise suppressing member 7 is 70% or more and 95% or less, and the content ratio of the binder agent is 5% or more and 30% or less. This makes it possible to appropriately impart flexibility to the temperature rise suppressing member 7 while suppressing the temperature rise of the housing 1 by the heat absorbing action of the heat absorbing agent. For example, when the temperature rise suppressing member 7 is a mixture of a heat absorbing agent and a binder, In the case of a mixture consisting of only the heat absorbing agent and the binder agent, the ratio of the heat absorbing agent to the binder agent can be selected within a range of 7:3 to 95:5. However, the content ratio of the heat absorbing agent and the content ratio of the binder agent in the temperature rise suppression member according to the present disclosure are not limited to the above ranges. In addition, the temperature rise suppression member may be configured to include materials other than the above-mentioned heat absorbing agent and the binder agent.

[0050] The temperature rise suppression member 7 can be provided as a coating film on the outer surface S1 of the housing 1, for example, by applying the temperature rise suppression member 7 to the outer surface S1 of the housing 1 in a dissolved state in a solvent and then drying the applied material.

[0051] [Operation] Hereinafter, the operation of the gas generator 100 and the airbag module assembly 1000 according to the first embodiment will be described with reference to Figs. 1 and 2. When a sensor (not shown) of the vehicle detects an impact, an ignition current is supplied to the pair of conductive pins 412, 412, and the igniter 41 is actuated. Then, the ignition charge accommodated in the cup body 411 of the igniter 41 burns, and the combustion products such as flame and high-temperature gas are discharged to the outside of the cup body 411. As a result, the first gas generating agent 110 accommodated in the transfer chamber 51 burns, and combustion gas is generated. The combustion gas of the first gas generating agent 110 breaks the seal tape that has been blocking the communication hole 52 and is discharged from the communication hole 52 to the outside of the transfer chamber 51. Then, the combustion gas of the first gas generating agent 110 comes into contact with the second gas generating agent 120, and the second gas generating agent 120 is ignited. The second gas generating agent 120 burns, generating high-temperature and high-pressure combustion gas in the combustion chamber 10. This combustion gas passes through the filter 6, whereby the combustion gas is cooled and combustion residue is collected. The combustion gas of the second gas generating agent 120, cooled and filtered by the filter 6, passes through the gap 13, breaks the seal tape blocking the gas discharge hole 11, and is discharged from the gas discharge hole 11 to the outside of the gas generator 100. After being discharged to the outside of the gas generator 100, the combustion gas of the second gas generating agent 120 flows into the airbag 200 in the module case 300. When the airbag 200 is inflated by the supply of gas, the front part 402 of the module case 300 is ruptured by the inflation pressure, and the airbag 200 is thrown out of the module case 300 and deployed in front of the occupant. This forms a cushion between the occupant and the hard structure, protecting the occupant from impact.

[0052] [Housing temperature rise suppression] When the gas generator 100 is activated, heat generated by the combustion of the gas generating agent is transferred to the housing 1, and then transferred by thermal conduction to the temperature rise suppression member 7 in contact with the housing 1. Therefore, as the temperature of the housing 1 rises, the temperature of the temperature rise suppression member 7 also rises. When the temperature of the temperature rise suppression member 7 rises to a predetermined temperature, the heat absorbing agent contained in the temperature rise suppression member 7 starts to change state or chemically. At this time, the heat absorbing agent removes thermal energy from the housing 1 and uses the thermal energy for the chemical or state change. As a result, the housing 1 is cooled by the heat absorbing action of the heat absorbing agent, and the temperature rise of the housing 1 is suppressed. Since the housing 1 absorbs heat from the contact portion with the temperature rise suppression member 7, the temperature rise is suppressed in the top plate portion 22 in contact with the temperature rise suppression member 7.

[0053] Here, as shown in FIG. 1, in the airbag module assembly 1000, the gas generator 100 is disposed so that the top plate portion 22 and the airbag 200 in a folded state face each other. Therefore, the airbag 200 that is deflated after deployment is likely to come into contact with the top plate portion 22 of the housing 1. If the top plate portion 22 of the housing 1 becomes excessively hot after the gas generator 100 is activated, the airbag 200 that is deflated after deployment will come into contact with the top plate portion 22 of the housing 1, causing the airbag 200 to melt and potentially generating undesirable gas or odor. Also, as shown in FIG. 2, in the gas generator 100 according to this embodiment, the upper end surface 61 of the metal filter 6 to which high-temperature combustion residue adheres is in contact with the top plate portion 22 of the housing 1. Furthermore, in the gas generator 100 according to this embodiment, the upper end portion of the metal inner cylinder member 5 filled with the first gas generating agent 110 is in contact with the top plate portion 22 of the housing 1. Therefore, in many cases, A large amount of heat is conducted to the top plate portion 22 via the filter 6 and the inner cylinder member 5. In particular, most of the heat is combustion residue generated from the first gas generating agent 110 and the second gas generating agent 120, which adheres to the inner surface of the housing 1 and the filter 6, causing the temperature of the housing 1 to rise. In other words, the temperature of the housing 1 gradually rises after the gas generator 100 is activated, so the temperature of the housing 1 rises to a maximum after the airbag 200 exerts its function (after the airbag 200 contracts). Therefore, if a gas generator 100 not equipped with a temperature rise suppression member 7 is activated, the top plate portion 22 is likely to reach a high temperature, and if the deployed bag comes into contact with the top plate portion 22 in this state, the bag will melt, leading to the generation of odors and undesirable gases.

[0054] In contrast to this, in the gas generator 100 according to this embodiment, the temperature rise suppression member 7 is provided in contact with the outer surface S22 of the top plate portion 22 of the housing 1. Therefore, as described above, the temperature rise of the housing 1 is suppressed at the top plate portion 22 which is a contact portion with the temperature rise suppression member 7. This suppresses the top plate portion 22 facing the airbag 200 in the airbag module assembly 1000 from becoming excessively hot. As a result, the airbag 200 is suppressed from melting due to the airbag 200 contracting after deployment coming into contact with the top plate portion 22 of the housing 1. This suppresses the generation of odors and undesirable gases. Furthermore, by suppressing the melting of the airbag 200 after the gas generator 100 is activated, the airbag 200 is suppressed from adhering to the housing 1 of the gas generator 100. As a result, the gas generator 100 after activation can be easily disposed of. Furthermore, according to the gas generator 100, the temperature rise of the housing 1 is suppressed, so that an occupant is prevented from being burned when he or she comes into contact with the housing 1.

[0055] For example, if an airbag 200 made of polyamide is used, the airbag 200 will melt at about 350°C. However, the gas generator 100 can prevent the airbag 200 from melting by using the temperature rise suppression member 7 to suppress the temperature of the housing 1 after the gas generator 100 is activated to, for example, 250°C or less.

[0056] Moreover, by imparting flexibility to the temperature rise suppression member 7 by the binder agent, the adhesion of the temperature rise suppression member 7 to the housing 1 is improved, so that the temperature rise suppression member 7 is less likely to peel off from the housing 1. Therefore, the temperature rise suppression member 7 is prevented from peeling off due to vibrations received during the running of the vehicle or the transportation of the gas generator 100, and from peeling off due to a temperature difference in the housing 1 before and after the operation of the gas generator 100. Furthermore, even if the housing 1 is deformed by the pressure of the combustion gas, the temperature rise suppression member 7 deforms in accordance with the deformation of the housing 1 due to its flexibility, so that damage to the temperature rise suppression member 7 is prevented. Furthermore, by imparting flexibility to the temperature rise suppression member 7, damage to the temperature rise suppression member 7 due to an external impact is also prevented. As a result, the temperature rise of the housing 1 after the operation of the gas generator 100 can be efficiently suppressed. Furthermore, by improving the adhesion performance of the temperature rise suppression member 7 to the housing 1, the amount of the temperature rise suppression member 7 can be reduced. As a result, the gas generator 100 can be made more space-saving. In this regard, the temperature rise suppression member 7 can be formed by separating the binder agent and the heat absorbing agent into layers and arranging the binder agent side in contact with the housing 1, or by forming a layer of binder agent on top of that (on top of the heat absorbing agent). However, in terms of imparting uniform flexibility throughout the temperature rise suppression member 7, it is preferable to arrange the heat absorbing agent and binder agent in a mixed state on the outer surface S22 of the top plate portion 22 of the housing 1.

[0057] [Actions and Effects] As described above, the gas generator 100 according to the first embodiment includes the gas generating agents 110, 120 that generate gas by combustion, the metal housing 1 that contains the gas generating agents therein, and the ignition device 4 that ignites the gas generating agents by activation. The housing 1 is formed with a gas exhaust hole 11 that exhausts gas generated by combustion of the gas generating agent to the outside. Thus, the gas generator 100 further comprises a temperature rise suppression member 7 provided in contact with the outer surface S1 of the housing 1 so as to cover at least a portion of the outer surface S1 (outer surface S22 in this example). This temperature rise suppression member 7 is configured to include a heat absorbing agent and a binder agent. When the temperature of the housing 1 rises due to combustion of the gas generating agent, the heat absorbing agent undergoes a chemical change or state change due to the heat of the housing 1, thereby absorbing the heat of the housing 1. The binder agent coexists with the heat absorbing agent so that the temperature rise suppression member 7 has flexibility, and is preferably mixed with the heat absorbing agent for use in a state integrated with the heat absorbing agent.

[0058] According to such a gas generator 100, the housing 1 rises due to the combustion of the gas generating agent. Then, the heat absorbing agent contained in the temperature rise suppression member 7 actively removes thermal energy from the housing 1 due to a state change or chemical change, and the temperature rise of the housing 1 after the gas generator 100 is activated can be suitably suppressed. Furthermore, the binder agent gives flexibility to the temperature rise suppression member 7, and the temperature rise suppression member 7 can be provided to the housing 1 with good adhesion. As a result, the temperature rise suppression member 7 is suppressed from peeling off from the housing 1 for a long period of time, and the temperature rise of the housing 1 can be suppressed more efficiently. According to such a gas generator 100, after the gas generator 100 is activated, the thermal influence on the parts (airbag 200 in this example) arranged around the housing 1 can be reduced. This is suitable for the case where parts (resin parts) that are easily affected by heat are arranged around the housing 1.

[0059] Furthermore, in gas generator 100 according to this embodiment, housing 1 has cylindrical peripheral wall portion 12 in which gas discharge hole 11 is formed, top plate portion 22 closing one end of peripheral wall portion 12, and bottom plate portion 32 closing the other end of peripheral wall portion 12, and gas discharge hole 11 is formed at a position such that distance d1 between gas discharge hole 11 and top plate portion 22 in the axial direction of housing 1 is shorter than distance between gas discharge hole 11 and bottom plate portion 32. Then, in gas generator 100, temperature rise suppression member 7 is provided on outer surface S22 of top plate portion 22 of housing 1, which is closer to gas discharge hole 11 than bottom plate portion 32. With this, by causing heat absorption by temperature rise suppression member 7 to act on top plate portion 22, temperature rise in top plate portion 22 of housing 1 can be efficiently suppressed. As a result, thermal effects on a component (airbag 200 in this example) arranged to face top plate portion 22 of housing 1 can be further reduced. In this regard, the airbag module assembly 1000 according to this embodiment includes a gas generator 100 and an airbag 200 that is arranged in a folded state and inflates and deploys by gas discharged from a gas discharge hole 11, and the gas generator 100 is arranged so that the top plate portion 22 of the housing 1 and the airbag 200 in the folded state face each other. Therefore, according to the gas generator 100 according to this embodiment, it is possible to reduce the thermal effect on the airbag 200, which is a component that is arranged to face the top plate portion 22 of the housing 1.

[0060] The technology according to the present disclosure does not limit the location of the temperature rise suppression member in the housing, but it is preferable to provide the temperature rise suppression member in a location where heat caused by the combustion of the gas generating agent is easily transferred, or in a location close to a component that should be avoided from being thermally affected, when the component is located nearby. For example, it is preferable to provide the temperature rise suppression member in contact with the outer surface of a portion of the housing that abuts against a filter to which high-temperature combustion residue adheres (at least one of the first blocking portion and the second blocking portion), or in contact with the outer surface of a portion adjacent to the combustion chamber in which the gas generating agent is burned (i.e., the portion that defines the combustion chamber).

[0061] [Variations] Hereinafter, there will be described a gas generator and an airbag module assembly according to a modified example of embodiment 1. In the description of the modified example, the differences from gas generator 100 described in Fig. 1 and Fig. 2 will be mainly described, and a detailed description of the similarities to gas generator 100 will be omitted.

[0062] [Variation 1] Fig. 3 is a partial enlarged view of gas generator 100A according to Modification 1 of Embodiment 1. Fig. 3 illustrates the vicinity of top plate portion 22, which is a portion of housing 1A according to Modification 1 where temperature rise suppression member 7 is provided. As shown in Fig. 3, gas generator 100A according to Modification 1 differs from gas generator 100 described above in that, of outer surface S1 of housing 1A, outer surface S22, which is a portion that comes into contact with temperature rise suppression member 7, is formed in an uneven shape. This uneven shape is formed, for example, by subjecting the surface of housing 1 to a roughening treatment. Regarding outer surface S1 of housing 1A, the entire outer surface S22 may be uneven, or only a portion of outer surface S22 may be uneven.

[0063] In gas generator 100A according to modification 1, by forming outer surface S22, which is the portion of outer surface S1 of housing 1A that comes into contact with temperature rise suppression member 7, into an uneven shape, it is possible to increase the contact area between the temperature rise suppression member 7 and outer surface S22, compared to when outer surface S22 is a flat surface. This improves the efficiency of heat transfer from the housing 1 to the temperature rise suppression member 7. As a result, heat absorption by the temperature rise suppression member 7 is promoted, making it possible to more efficiently suppress the temperature rise of the housing 1.

[0064] [Variation 2] Fig. 4 is a cross-sectional view showing an airbag module assembly 1000B including a gas generator 100B according to Modification 2 of Embodiment 1 in a pre-activation state. Fig. 5 is a cross-sectional view showing a gas generator 100B according to Modification 2 of Embodiment 1 in a pre-activation state. In Figs. 4 and 5, a cross section along the central axis A1 of the housing 1 is shown.

[0065] As shown in FIG. 5, the inner cylinder member 5B of the second modified example is formed into a bottomed cylindrical shape with one end (upper end) closed and the other end (lower end) open, and is attached to the bottom plate portion 32 by welding the collar 42 of the ignition device 4 to the lower end.

[0066] Modification 2 illustrates a structure for suppressing a temperature rise on the bottom plate portion 32 side of the housing 1. Specifically, in gas generator 100B according to modification 2, temperature rise suppression member 7 is provided in contact only with outer surface S32 of bottom plate portion 32 of housing 1. The entire area of ​​outer surface S32 of bottom plate portion 32 excluding mounting hole 32a is covered with film-like temperature rise suppression member 7. More specifically, temperature rise suppression member 7 is in close contact with outer surface S32 over the entire area of ​​bottom plate portion 32, which is the portion of the housing 1 where temperature rise suppression member 7 is arranged.

[0067] Moreover, gas generator 100B according to modification 2 is equipped with a label sheet 8. Label sheet 8 is a sheet-like member on which predetermined information is displayed, and is attached to temperature rise suppressing member 7 such that temperature rise suppressing member 7 is interposed between label sheet 8 and housing 1. Label sheet 8 is attached to temperature rise suppressing member 7 with one of its two surfaces (mounting surface 8a) facing and in contact with temperature rise suppressing member 7. Predetermined information is displayed on the other surface (display surface 8b) of label sheet 8.

[0068] Predetermined information, for example, information relating to gas generator 100B, is displayed on display surface 8b of label sheet 8. Information relating to gas generator 100B may include, for example, handling precautions, manufacturer information, model number, barcode for management, etc. However, the information displayed on a label sheet according to the present disclosure is not limited to the above.

[0069] The material of the label sheet 8 is not particularly limited, but a heat-resistant resin material such as a polyester film can be used. The label sheet 8 can be attached to the bottom plate portion 32 by utilizing the adhesiveness of the temperature rise suppression member 7, for example. In other words, the temperature rise suppression member 7 can be interposed between the housing 1 and the label sheet 8 as an adhesive (adhesive layer). An adhesive may be separately applied to the attachment surface 8a, and the label sheet 8 may be attached to the temperature rise suppressing member 7. Furthermore, the method for displaying predetermined information on the display surface 8b of the label sheet 8 is not particularly limited, but the predetermined information can be written on the display surface 8b by, for example, printing or engraving.

[0070] 4, in an airbag module assembly 1000B, the bottom plate portion 32 of the housing 1 is exposed to the outside of the module case 300. In a gas generator 100B according to Modification 2, the label sheet 8 is attached to an outer surface S32 of the bottom plate portion 32 of the housing 1 via a temperature rise suppression member 7 so that the label sheet 8 can be seen from outside the module when incorporated into the airbag module assembly 1000B. However, the position at which the label sheet 8 is attached is not limited to the bottom plate portion 32.

[0071] According to gas generator 100B according to modification 2, by interposing temperature rise suppression member 7 between label sheet 8 and bottom plate portion 32 of housing 1, it is possible to suppress a temperature rise of bottom plate portion 32 after activation of gas generator 100B. According to this, by suppressing a temperature rise of bottom plate portion 32 to which label sheet 8 is attached via temperature rise suppression member 7, it is possible to suppress a temperature rise of label sheet 8 after activation of gas generator 100B. Thereby, it is possible to prevent a decrease in visibility of the display content of label sheet 8 due to discoloration, denaturation, burning, etc. of label sheet 8 due to high temperature after activation of gas generator 100B, for example. In other words, it is possible to reduce the thermal effect on label sheet 8 after activation of gas generator 100B.

[0072] <Embodiment 2> Hereinafter, there will be described a gas generator and an airbag module assembly according to embodiment 2. In the description of embodiment 2, differences from gas generator 100 according to embodiment 1 described in Fig. 1 and Fig. 2 will be mainly described, and detailed description of similarities with gas generator 100 will be omitted.

[0073] Fig. 6 is a cross-sectional view showing an airbag module assembly 1000C including a gas generator 100C according to embodiment 1 in a state before activation. Fig. 6 shows a cross section perpendicular to the central axis A1 of the housing 1C. Note that Fig. 6 omits illustration of the inner cylinder member 5C, filter 6, gas generating agent, etc. of the gas generator 100C. Fig. 7 is a cross-sectional view showing an airbag gas generator 100C according to embodiment 1 in a state before activation. Fig. 7 shows a cross section along the central axis A1 of the housing 1C.

[0074] 6, the airbag module assembly 1000C includes a gas generator 100C, an airbag 200, and a module case 600 that houses them. The airbag module assembly 1000C is, for example, a front airbag device installed in the passenger seat of a vehicle (more specifically, on the dashboard of the passenger seat). However, the airbag module assembly 1000C may be applied to a front airbag device for the driver's seat, or may be applied to a side airbag device.

[0075] The module case 600 is a box that houses the gas generator 100C and the airbag 200. The module case 600 includes an airbag cover 700 and a retainer 800. The airbag cover 700 includes a rectangular frame-shaped side wall portion 701 that forms a side surface of the module case 600, and a front portion 702 that closes one end of the side wall portion 701 and forms the front surface of the module case 600. The airbag cover 700 is installed so that the front portion 702 forms, for example, a part of the dashboard of the vehicle. The retainer 800 is fixed to a vehicle structure (not shown), and is engaged with the side wall portion 701 of the airbag cover 700 to form a housing space for the gas generator 100C and the airbag 200 together with the airbag cover 700. The gas generator 100C is disposed in the module case 600 so that the peripheral wall portion 12 of the housing 1C faces the front portion 702 side. In addition, the peripheral wall of the gas generator 100 The airbag 200 in a folded state is disposed between the airbag 12 and the front part 702 of the module case 600.

[0076] The airbag module assembly 1000C is installed in the vehicle so that the front part 702 of the airbag cover 700 faces the occupant (in this example, the passenger in the front seat) who is to be protected by the airbag 200. When the gas generator 100C is activated, the front part 702 is ruptured by the pressure caused by the expansion of the airbag 200, and the airbag 200 jumps out of the module case 600 and deploys in front of the occupant. This protects the occupant from impact.

[0077] 7, gas generator 100C according to embodiment 2 is formed in a long tubular (cylinder-like) shape, and includes ignition device 4, inner cylinder member 5C, filter 6, first gas generating agent 110, second gas generating agent 120, metal housing 1C for accommodating these, temperature rise suppression member 7 provided on outer surface S1 of housing 1C, and partition member 9. Gas generator 100C according to the present embodiment is configured as a pyrotype gas generator using only a gas generating agent as a gas source, but may also be configured as a hybrid type gas generator using a gas generating agent and pressurized gas as a gas source.

[0078] As shown in Fig. 7, a housing 1C according to the second embodiment is formed in a bottomed cylindrical shape with one end (upper end) closed and the other end (lower end) open. The housing 1C has a cylindrical peripheral wall portion 12, a top plate portion 14 closing one end (upper end) of the peripheral wall portion 12, and a fixing portion 15 extending radially inward from the other end (lower end) of the peripheral wall portion 12. In a gas generator 100C according to the second embodiment, the ignition device 4 is fixed to the lower end of the peripheral wall portion 12 by crimping the fixing portion 15 in a state in which the ignition device 4 is fitted into the lower end of the peripheral wall portion 12. The inner cylinder member 5C is formed in a cylindrical shape with both ends open, and is attached to the housing 1C by fitting (pressing) a collar 42 of the ignition device 4 into the lower end with the upper end abutting against the top plate portion 14 of the housing 1C. The inner cylinder member 5C has a first outer diameter portion 53 including its upper end portion and a second outer diameter portion 54 including its lower end portion. The first outer diameter portion 53 has a smaller outer diameter than the second outer diameter portion 54, and the first outer diameter portion 53 and the second outer diameter portion 54 are connected by a step portion 55 extending in the radial direction. The communication hole 52 is formed in the first outer diameter portion 53. The filter 6 is supported by abutting the upper end surface 61 against the top plate portion 14, and is supported by abutting the lower end surface 62 against the step portion 55. The partition member 9 is a member that divides the internal space of the inner cylinder member 5C in the axial direction. The partition member 9 divides the internal space of the inner cylinder member 5C into a first combustion chamber 56 surrounded by the second outer diameter portion 54 and a second combustion chamber 57 surrounded by the first outer diameter portion 53. A plurality of through holes 91 are formed in the partition member 9, allowing communication between the first combustion chamber 56 and the second combustion chamber 57. A first gas generating agent 110 is disposed in the first combustion chamber 56, and a second gas generating agent 120 is disposed in the second combustion chamber 57.

[0079] As shown in FIG. 6, in the airbag module assembly 1000C, the gas generator 100C is disposed so as to face the airbag 200 in a state in which the peripheral wall portion 12 of the housing 1C is folded. More specifically, a portion of half the circumference of the peripheral wall portion 12 in the circumferential direction faces the airbag 200. Here, a portion of the peripheral wall portion 12 that faces the airbag 200 in the airbag module assembly 1000C is referred to as a facing portion 121. In the gas generator 100C according to the second embodiment, the gas discharge hole 11 is formed only in the facing portion 121 of the peripheral wall portion 12. However, the present disclosure is not limited thereto. For example, when the airbag module assembly 1000C is applied to a side airbag device, the gas discharge hole 11 may be formed on the entire circumference of the peripheral wall portion 12.

[0080] 6, in the gas generator 100C according to the second embodiment, the temperature rise suppression member 7 is provided in contact with only the outer surface S12 of the facing portion 121, which is the portion of the housing 1C facing the airbag 200. The temperature rise suppressing member 7 is provided so as to cover the entire area of ​​the facing portion 121. More specifically, the temperature rise suppressing member 7 is in close contact with the outer surface S12 over the entire area of ​​the facing portion 121, which is the portion of the housing 1C where the temperature rise suppressing member 7 is disposed.

[0081] In the second embodiment, when the igniter 41 is activated, the combustion product of the ignition charge is discharged into the first combustion chamber 56, and the first gas generating agent 110 accommodated in the first combustion chamber 56 is burned, generating combustion gas. The combustion gas of the first gas generating agent 110 is discharged into the second combustion chamber 57 through the through hole 91 of the partition member 9. Then, the combustion gas of the first gas generating agent 110 comes into contact with the second gas generating agent 120, and the second gas generating agent 120 is ignited. The second gas generating agent 120 burns, generating high-temperature and high-pressure combustion gas in the second combustion chamber 57. This combustion gas passes through the communication hole 52 and the filter 6 to be cooled and filtered, and then passes through the gap 13 and is discharged from the gas discharge hole 11 to the outside of the gas generator 100C. The combustion gas of the second gas generating agent 120 flows into the airbag 200 in the module case 600 after being discharged to the outside of the gas generator 100C. When the airbag 200 is inflated by the supply of gas, the front part 702 of the airbag cover 700 is torn by the inflation pressure, and the airbag 200 is ejected to the outside of the module case 600 and deployed in front of the occupant. This forms a cushion between the occupant and the hard structure, protecting the occupant from impact.

[0082] In the airbag module assembly 1000C according to the second embodiment, the gas generator 100C is disposed so that the opposing portion 121 of the peripheral wall portion 12 faces the airbag 200 in a folded state. Therefore, the airbag 200 that is deflated after deployment is in a state where it is likely to come into contact with the opposing portion 121 of the housing 1C. In contrast, in the gas generator 100C according to the present embodiment, the temperature rise suppression member 7 is provided in contact with the outer surface S12 of the opposing portion 121 of the housing 1C. Therefore, the temperature rise of the housing 1C is suppressed in the opposing portion 121, which is a contact portion with the temperature rise suppression member 7. This suppresses the opposing portion 121 that faces the airbag 200 in the airbag module assembly 1000C from becoming excessively hot. As a result, in the present embodiment, it is possible to reduce the thermal effect on the airbag 200, which is a component disposed to face the opposing portion 121 of the housing 1C.

[0083] As described above, gas generator 100C according to embodiment 2 can reduce the thermal effects on components arranged around peripheral wall portion 12 of housing 1C by providing temperature rise suppression member 7 on outer surface S12 of peripheral wall portion 12. Note that temperature rise suppression member 7 may be provided so as to contact the entire peripheral wall portion 12.

[0084] <Other> Although the embodiments of the technology according to the present disclosure have been described above, each aspect disclosed in this specification can be combined with any other features disclosed in this specification. [Explanation of symbols]

[0085] 1. Housing 4...Ignition device 7. Temperature rise suppression material 8. Label sheet 11 Gas exhaust hole 12...Peripheral wall part 22... Top plate portion (an example of a first blocking portion) 32... Bottom plate portion (an example of a second blocking portion) 100 Gas generator 110... First gas generating agent (an example of a gas generating agent) 120... Second gas generating agent (an example of a gas generating agent) 200···Airbag 1000 Airbag module assembly

Claims

1. A gas generating agent that generates gas by combustion; a metal housing that accommodates the gas generating agent therein and has a gas exhaust hole formed therein for exhausting the gas generated by combustion of the gas generating agent to the outside; an ignition device that ignites the gas generating agent when activated; a temperature rise suppressing member provided in contact with the outer surface of the housing so as to cover at least a portion of the outer surface; Equipped with The temperature rise suppression member includes a heat absorbing agent that absorbs heat from the housing by undergoing a chemical change or a state change due to heat of the housing when the temperature of the housing rises due to combustion of the gas generating agent, and a binder agent that coexists with the heat absorbing agent so that the temperature rise suppression member has flexibility. Gas generator.

2. The binder is mixed with the heat absorbing agent.

2. The gas generator according to claim 1.

3. The heat absorbing agent includes at least one selected from the group consisting of fatty acid polycarbonate, magnesium carbonate, fumaric acid, and terephthalic acid.

3. A gas generator according to claim 1 or 2.

4. The binder agent includes a compound having a hydroxyl group or a carbonyl group.

3. A gas generator according to claim 1 or 2.

5. The content ratio of the heat absorbing agent in the temperature rise suppression member is 70% or more and 95% or less, The content ratio of the binder in the temperature rise suppression member is 5% or more and 30% or less.

3. A gas generator according to claim 1 or 2.

6. the housing has a cylindrical peripheral wall portion in which the gas discharge hole is formed, a first closing portion that closes one end of the peripheral wall portion, and a second closing portion that closes the other end of the peripheral wall portion, the gas discharge hole is formed at a position such that a distance between the gas discharge hole and the first closing portion in an axial direction of the housing is shorter than a distance between the gas discharge hole and the second closing portion, The temperature rise suppression member is provided on an outer surface of the first closing portion.

3. A gas generator according to claim 1 or 2.

7. the housing has a cylindrical peripheral wall portion in which the gas exhaust hole is formed, The temperature rise suppression member is provided on an outer surface of the peripheral wall portion.

3. A gas generator according to claim 1 or 2.

8. A portion of the outer surface of the housing that comes into contact with the temperature rise suppression member is formed in an uneven shape.

3. A gas generator according to claim 1 or 2.

9. Further comprising a label sheet for displaying predetermined information; the label sheet is attached to the temperature rise suppressing member such that the temperature rise suppressing member is interposed between the label sheet and the housing.

3. A gas generator according to claim 1 or 2.

10. A gas generator according to claim 6; an airbag that is arranged in a folded state and that is inflated and deployed by the gas discharged from the gas discharge hole; An airbag module assembly comprising: The gas generator is disposed so that the first closing portion faces the airbag in a folded state. Airbag module assembly.

11. A gas generator according to claim 7; an airbag that is arranged in a folded state and that is inflated and deployed by the gas discharged from the gas discharge hole; An airbag module assembly comprising: the gas generator is disposed so that the peripheral wall portion faces the airbag in a folded state, The temperature rise suppression member is provided on an outer surface of a portion of the peripheral wall portion that faces the airbag. Airbag module assembly.

Images