Safety valve for high-pressure tank

Abstract

[Problem] To provide a safety valve that prevents gas from catching fire when an explosive for actuating the valve is ignited. [Solution] A safety valve 30 includes a body part 31 and an igniter 34. The body part 31 includes: an externally threaded region 31A; an internal space 31B in which the igniter 34 is installed; a hole 31C communicating with a space 10a of a tank body 10; an openable part 32 that is a bottom part of the hole 31C and is opened by ignition of the igniter 34; and a discharge port 33 for discharging gas during actuation. A fastening member 36 is provided with a cylindrical member 42, an opening 42a is formed in a bottom part of the cylindrical member 42, and an O-ring 43 is installed at an intermediate point of the inner wall of the opening 42a. A piston member 44 having a rod-like part 44a with a tip passing through the opening 42a is provided inside the cylindrical member 42. The piston member 44 includes a recessed receiving part 44b for receiving flame of the igniter 34. A cooling agent 45 is filled between an inner wall of the cylindrical member 42 and a surface of the piston member 44A.

Description

High-pressure tank safety valve

[0001] The present invention relates to a safety valve for a high-pressure tank.

[0002] Some high-pressure tanks (gas cylinders) that store compressed gases and other gases are equipped with a safety valve (also called a fusible plug valve) that melts and opens when the ambient temperature rises abnormally for some reason. For example, if the temperature of the high-pressure tank rises abnormally due to a fire, the safety valve will activate and prevent the high-pressure tank from bursting.

[0003] Patent No. 5007809

[0004] When the safety valve (fusible plug valve) of Patent Document 1 is applied to a high-pressure tank of a flammable gas (such as hydrogen gas), it takes time for the fusible plug to completely melt, so a safety valve driven by explosives is advantageous for quickly activating the safety valve. However, when applied to a high-pressure tank of a flammable gas (such as hydrogen gas), there is a concern that the flammable gas may ignite.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a fast acting safety valve that does not catch fire and that can use an ignition means as a driving force.

[0006] (1) The present invention is a safety valve for a high-pressure tank that can be connected to an opening of a tank body filled with a fluid, comprising: a main body having an outlet that comes into contact with the external environment and a flow path that can connect the opening to the external environment via the outlet; and a valve that is provided at any position on the flow path and normally closes the flow path and opens the flow path when an abnormally high temperature occurs or an abnormality is detected, the valve having an openable part that is opened by actuation of an opening means provided on the flow path, the opening means being provided in the flow path downstream of the openable part and opening the openable part using energy obtained by ignition of explosives as a driving source, and the valve being provided with flame quenching means for a flame that is generated by ignition of the explosives when the opening means is actuated.

[0007] (2) In the high-pressure tank safety valve of (1) above, the explosive in the opening means is an igniter that is activated by the flow of an electric current, or an auto-ignition agent that automatically ignites at a predetermined temperature or higher, and the flame quenching means is an quenching agent or flame quenching member that extinguishes a flame that occurs when the igniter or the auto-ignition agent is activated, and further comprises: a cylindrical member having the igniter or the auto-ignition agent at one end and a bottom with a hole at the other end; and a piston member at least a portion of which is provided inside the cylindrical member and is initially provided so as to penetrate the hole, and which slides in the direction of penetration of the hole by a pressure wave generated by ignition of the igniter or automatic ignition of the auto-ignition agent when the igniter or the auto-ignition agent is activated, thereby opening the releasable portion, and it is preferable that the flame quenching means is provided at least partially between the inner wall of the cylindrical member and the piston inside the cylindrical member. The explosives referred to here refer to explosive compositions such as ignition charges, ignition agents, AI agents, and gas generators, as well as pyrotechnics incorporating these into igniters or gas generators.

[0008] (3) From another viewpoint, in the safety valve for a high-pressure tank of (1) above, the explosive in the opening means may be an igniter that is activated by the flow of an electric current, or an auto-ignition agent that automatically ignites at a predetermined temperature or higher, and the flame quenching means may be an quenching agent or member that extinguishes a flame that occurs when the igniter or the auto-ignition agent is activated, and further include: a cylindrical member having the igniter or the auto-ignition agent at one end and having a bottom at the other end; and a piston member that is provided inside the cylindrical member and slides to the other end of the cylindrical member by a pressure wave generated by ignition of the igniter or automatic ignition of the auto-ignition agent when the igniter or the auto-ignition agent is activated, thereby sequentially opening the bottom and the releasable portion of the cylindrical member, and the flame quenching means may be provided at least partially between the inner wall of the cylindrical member and the piston inside the cylindrical member.

[0009] (4) From another viewpoint, in the safety valve for a high-pressure tank of (1) above, the explosive in the opening means may be an igniter that is activated by the flow of an electric current, or an auto-ignition agent that automatically ignites at a predetermined temperature or higher, and the flame quenching means may be a flame quenching member that quenches a flame that occurs when the igniter or the auto-ignition agent is activated, and further comprises a cylindrical member having the igniter or the auto-ignition agent at one end and a bottom with a hole at the other end, the flame quenching member being located inside or outside the cylindrical member or inside the hole so as to cover the hole, and the openable portion may be ruptured or split open by a pressure wave obtained after the flame is quenched by the flame quenching member.

[0010] (5) In the safety valve for a high-pressure tank of (4) above, it is preferable that the flame quenching means further includes an anti-flame agent, the anti-flame agent being disposed in at least a portion of the interior of the tubular member, and the openable portion is ruptured or split open by a pressure wave obtained after the flame is extinguished by the anti-flame agent and the anti-flame agent.

[0011] According to the present invention, it is possible to provide a safety valve for a high-pressure tank that does not ignite and can use ignition means as a driving force.

[0012] FIG. 1 is a partial cross-sectional schematic view of a high-pressure tank equipped with a safety valve according to a first embodiment of the present invention. FIG. 2 is a partial cross-sectional schematic view showing the safety valve of FIG. 1. FIG. 3 is a partial cross-sectional schematic view showing a safety valve according to a second embodiment of the present invention. FIG. 4 is a partial cross-sectional schematic view showing a safety valve according to a third embodiment of the present invention. FIG. 5 is a partial cross-sectional schematic view showing a safety valve according to a fourth embodiment of the present invention. FIG. 6 is a partial cross-sectional schematic view showing a safety valve according to a fifth embodiment of the present invention. FIG. 7 is a partial cross-sectional schematic view showing a safety valve according to a sixth embodiment of the present invention. FIG. 8 is a partial cross-sectional schematic view showing a safety valve according to a seventh embodiment of the present invention. FIG. 9 is a partial cross-sectional schematic view showing a safety valve according to an eighth embodiment of the present invention. FIG. 10 is a partial cross-sectional schematic view showing a safety valve according to an eleventh embodiment of the present invention. FIG. 11 is a schematic view of a vehicle equipped with a high-pressure tank including a safety valve according to a twelfth embodiment of the present invention. FIG. 12 is a partial cross-sectional schematic view showing a safety valve according to a thirteenth embodiment of the present invention. FIG. 13 is a partial cross-sectional schematic view showing a safety valve according to a fourteenth embodiment of the present invention.

[0013] <First Embodiment> A first embodiment of the present invention will be described in detail below with reference to Figures 1 and 2. The present invention can be embodied in various forms without departing from the gist of the present invention. For example, in the following embodiment, an example is shown in which the present invention is applied to a high-pressure tank for fuel gas (high-pressure hydrogen) mounted on a fuel cell vehicle, but the present invention is not limited to this and can be applied to high-pressure tanks that store other types of compressed gas or liquefied gas.

[0014] As shown in FIG. 1, the high-pressure tank 100 has a tank body 10 with a space 10a inside for filling and storing high-pressure gas (e.g., hydrogen gas), an opening 11 provided at one end (the lower end in FIG. 1) of the tank body 10, and an opening 12 provided at the other end (the upper end in FIG. 1) of the tank body 10.

[0015] A nozzle member (not shown) is provided at the opening 11, and a valve (tank valve) 20 is attached to this nozzle member. The valve 20 is provided with a supply port 21 for supplying gas. This supply port 21 is connected to a pipe (not shown) that leads to an engine powered by hydrogen, such as a fuel cell or a hydrogen engine, and under normal circumstances (when no abnormally high temperature due to a fire has occurred), the gas in the space 10a of the tank body 10 is supplied to the engine powered by hydrogen via the valve 20, supply port 21, and pipe.

[0016] The opening 12 has a female thread (not shown) cut therein, and the safety valve 30 is attached by screwing it into a male thread (not shown) provided on a part of the outer periphery of the safety valve 30 on the tank body 10 side (male threaded portion 31A on the tank body 10 side of the outer periphery of the main body portion 31 described later).

[0017] The safety valve 30 has a main body 31 and an igniter 34 (an example of an opening means that is provided downstream of the openable portion 32 in the gas flow direction, with the tank main body 10 side being the upstream side in the flow path described below, and that opens the openable portion 32 using energy obtained by driving (activation) as a driving source). The main body 31 has a male threaded portion 31A where a male thread is cut, an internal space 31B in which the igniter 34 is provided, a hole 31C that communicates with the space 10a of the tank main body 10, the openable portion 32 at the bottom of the hole 31C that opens (a hole is formed by melting, splitting, breaking, or the like) when the igniter 34 is ignited, and an outlet 33 that communicates with the external environment and discharges gas when activated.

[0018] Here, when the space 10a of the tank body 10 is filled with hydrogen gas, it is preferable to use a material for the body portion 31 that has been designed to prevent hydrogen embrittlement, such as SUS316 or SUS316L.

[0019] Furthermore, the releasable portion 32 may have a weakened portion such as a notch formed at a location where the tip of the rod-shaped portion 44a of the piston member 44 (described later) collides during activation. This makes it easier to rupture and reduces the amount of debris that is scattered. The releasable portion 32 may be formed with a thickness that is sufficient to prevent deformation due to the gas pressure inside the tank under normal conditions and to be ruptured by the piston member 44 that moves when the igniter 34 is activated. While the releasable portion 32 is integrally formed with the main body 31, it is not limited to this. For example, a through hole may be provided, and a rupture disk may be provided to block the through hole, and the rupture disk may be ruptured by the piston member 44 that moves when the igniter 34 is activated.

[0020] The size of the total opening area varies depending on the critical constant (σ), gas constant (R), temperature (T), pressure inside the tank (P), gas volume inside the tank (V), and gas discharge time (t). The general formula is as follows:

[0021] However, technically, the capacity of the tank that can be stored is limited, and it is difficult to manufacture a small total opening area from a processing technology perspective. Also, if the total opening area is small, there is a risk that the outlet will be clogged with foreign matter, making it impossible to achieve the effect of discharging the gas. Furthermore, if the total opening area is made larger than a certain level, the gas discharge speed will increase and the high concentration gas will mix with oxygen in the air, increasing the risk of ignition and explosion. Taking all of these factors into consideration, in order to discharge the gas at an appropriate speed, the total opening area of ​​the outlet 33 is set to 0.008 to 5.5 (mm ２ ), and 0.08 to 3.2 (mm ２ ) is more preferable.

[0022] Furthermore, it is preferable that the outlet 33 be provided facing the ground, or that additional piping be attached so that the gas can be discharged to the ground. This allows only an amount that will have a minor impact (an amount that is unlikely to cause damage to people or equipment) even if the hydrogen gas ignites to be discharged from the outlet 33, and also allows the hydrogen gas to be discharged relatively smoothly, so that even if an abnormally high temperature occurs due to a fire, it is possible to prevent the tank body 10 from bursting and to minimize the impact of the discharged hydrogen gas igniting.

[0023] A fixing member 36 is fixed to the external environment side of the internal space 31B (the upper side in FIG. 2 ), and fixes and holds a portion of the igniter 34 on the external environment side. A cylindrical member 42 is provided on the openable portion 32 side of the fixing member 36 so as to cover the periphery of the openable portion 32 side of the igniter 34. A hole 42a is formed in the bottom of the cylindrical member 42, and an O-ring 43 (sealing member) is provided midway along the inner wall of the hole 42a. A piston member (sliding member) 44 is provided inside the cylindrical member 42 so that the tip of a rod-shaped portion 44a initially passes through the hole 42a. The piston member 44 also has a recessed receiving portion 44b that receives the flame of the igniter 34. Furthermore, a heat reducing and flame quenching agent 45 (an example of a flame quenching means) is filled between the inner wall of the cylindrical member 42 and the surface of the piston member 44, and an O-ring 43 seals the heat reducing and flame quenching agent 45 so that it does not leak out of the cylindrical member 42 through the hole 42a. The heat reducing and flame quenching agent 45 is, for example, salt, potassium chloride, oxalate, carboxylate, or the like, but any flame quenching agent may be used as long as it can reduce the heat of the flame generated by the igniter 34 and can extinguish more flame than necessary after the igniter 34 is activated (reducing the energy of the flame). Therefore, a fire extinguishing agent or insulating oil may be used instead of the heat reducing and flame quenching agent 45.

[0024] The igniter 34 is used to generate a flame and includes an ignition portion (not shown) and a pair of terminal pins 35. The ignition portion contains an ignition charge that ignites and burns to generate a flame when activated, and a resistor for igniting the ignition charge.

[0025] More specifically, the ignition unit includes a squib cup formed in a cup shape, and a plug that closes the open end of the squib cup and through which a pair of terminal pins 35 are inserted and held, a resistor (bridge wire) is attached so as to connect the tips of the pair of terminal pins 35 inserted into the squib cup, and an ignition charge is loaded into the squib cup so as to surround or be close to the resistor. If necessary, an ignition charge and / or AI agent can be loaded into the squib cup in addition to the ignition charge.

[0026] Here, nichrome wire or the like is generally used as the resistor, and ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), ignition charge (basic copper nitrate, zirconium) lead tricinate, etc. are generally used as the ignition charge. ３ , B / NaNO ３ , Sr(NO ３ ) ２ Examples of AI agents that can be used include compositions consisting of metal powder / oxidizer, such as those listed above, thermite compositions, compositions consisting of titanium hydride / potassium perchlorate, and compositions consisting of titanium / potassium perchlorate. Examples of AI agents that can be used include compositions consisting of B / 5-aminotetrazole / potassium nitrate / molybdenum trioxide, 5-aminotetrazole / potassium nitrate / molybdenum trioxide, 5-aminotetrazole / potassium nitrate / molybdenum trioxide, and 5-aminotetrazole / potassium nitrate / strontium nitrate / molybdenum trioxide, compositions consisting of 3-nitro-1,2,4-triazol-5-one / sodium nitrate, and smokeless powders consisting mainly of nitrocellulose. The squib cups and plugs described above are generally made of metal or plastic.

[0027] The pair of terminal pins 35 are connected to an ignition unit to ignite the ignition charge, and are also connected to a power source 40 (such as a battery) via wiring 41. The power source 40 receives a command signal from a control unit (not shown) when, for example, a temperature detected by a temperature sensor (not shown) that detects the external temperature of the tank body 10 exceeds a predetermined value, and passes a predetermined amount of current through the pair of terminal pins 35 via wiring 41. That is, when a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and the ignition charge begins to burn. The high-temperature flame generated by the combustion ruptures the squib cup containing the ignition charge. The time from when current flows through the resistor to when the igniter 34 is activated is generally 2 ms or less when nichrome wire is used for the resistor.

[0028] Here, as a modified example, an igniter may be combined with a gas generating agent, if necessary (the gas generating agent is burned by a flame generated by activation of the igniter to generate gas). By combining an igniter with a gas generating agent, the releasable portion can be opened more quickly upon activation. Furthermore, if the filling pressure of the fluid filled in the high-pressure tank is high, the strength of the releasable portion must also be set high, and therefore, in order to instantly open the releasable portion upon activation, it is necessary to combine an igniter with a gas generating agent. This modified example can also be applied to other embodiments and modified examples that use an igniter.

[0029] The gas generating agent is composed of an appropriate combination of a fuel and an oxidizer. The fuel component is one or more selected from the group consisting of guanidine derivatives, tetrazole derivatives, urea derivatives, triazole derivatives, hydrazine derivatives, triazine derivatives, and azodicarbonamide. The oxidizer component is one or more selected from the group consisting of metal oxides, chlorates, perchlorates, nitrates, basic nitrates, and basic carbonates. If necessary, the agent may also contain a burning rate modifier and a binder.

[0030] Next, the operation of the safety valve 30 in the high-pressure tank 100 in this embodiment will be described.

[0031] Referring to FIG. 1 , when the high-pressure tank 100 is exposed to an abnormally high temperature above a predetermined temperature, the temperature sensor detects the temperature. Based on this, a current flows from the power supply 40 to the igniter 34, which is a driving source, via the wiring 41 in response to a command from the control unit, activating the igniter 34. The flame generated by the activation of the igniter 34 is received by the receiving portion 44b of the piston member 44. The piston member 44, receiving the flame energy, moves toward the openable portion 32. The tip of the rod-shaped portion 44a of the piston member 44 then splits or breaks the openable portion 32, forming a hole. At this time, the heat-reducing and flame-extinguishing agent 45 reduces the heat of the flame and extinguishes any excess flame. Subsequently, after the hole is formed in the openable portion 32, the piston member 44 is pushed back toward the internal space 31B by the pressure of the gas inside the tank body 10. This establishes communication between the internal space 31B and the hole 31C through the hole. By connecting the internal space 31B and the hole 31C, the gas filled in the space 10a of the tank body 10 is discharged to the external environment through the flow path formed by the hole 31C, the internal space 31B, and the exhaust port 33.

[0032] The safety valve 30 configured as described above can use an ignition means as a driving force without ignition. Furthermore, a predetermined amount of gas can be discharged from the beginning of operation (e.g., an amount that will have only a minor impact even if ignition occurs). Furthermore, since the cylindrical member 42 is filled with the heat-reducing and flame-extinguishing agent 45, even if the gas in the high-pressure tank 100 is flammable, ignition of the flammable gas can be prevented even when the igniter 34 is used as a means for forming the hole in the openable portion 32.

[0033] Furthermore, when used in a high-pressure tank 100 filled with hydrogen gas, by making the diameter of the outlet 33 0.001 mm to 0.2 mm, and more preferably 0.01 mm to 0.1 mm, it is possible to discharge an amount of hydrogen gas from the outlet 33 that will have only a minor impact even if the hydrogen gas ignites, and since the hydrogen gas can be discharged relatively smoothly, it is possible to prevent the tank body 10 from bursting even if an abnormally high temperature occurs due to a fire, and to minimize the impact of the discharged hydrogen gas igniting.

[0034] Second Embodiment Next, a second embodiment of the present invention will be described in detail with reference to Fig. 3. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above embodiment are similar, and therefore description thereof will be omitted unless otherwise specified.

[0035] As shown in FIG. 3( a), the safety valve 130 differs from the safety valve 30 of the first embodiment mainly in that the main body 131 has an overall elongated shape compared to the main body 31 of the first embodiment, that the openable portion 132 which is the bottom that closes the hole portion 131C is formed by welding, crimping, cutting or attaching a plate-like member, that one or more discharge ports 133 are formed, that the igniter 134 is fixed by crimping or molded with a fixing member 136, and that the space between the main body 131 and the igniter 134 is sealed with an O-ring 137 (sealing member).

[0036] Because a portion of the releasable portion 132 is exposed to compressed gas for a long period of time, it is desirable for the releasable portion 132 to be constructed from a thin metal plate made of a nickel alloy. For example, a heat-resistant and corrosion-resistant metal thin plate (e.g., approximately 200 μm thick) is preferably used for the releasable portion 132. A thin plate made of stainless steel such as SUS316 or SUS316L (JIS standard symbol) or an Inconel alloy (Inconel 625) containing 10% Ni (by weight), 23% Cr, 6% Mn, 2% Mo, 0.01% C, and 0.5% N (by weight) is particularly preferred. Furthermore, the releasable portion 132 may have a fragile portion, such as a notch, at a location where the tip of the rod-shaped portion 144a of the piston member 144 collides during operation.

[0037] Of the multiple exhaust ports 133, those that can be installed facing the ground may be left as they are, but those that cannot be installed facing the ground are preferably installed with piping so that the gas is discharged to the ground side. In the case of a structure that prevents the exhaust gas from burning, or a heat-shielding and flame-shielding structure so that even if the exhaust gas burns, the flame does not cause harm to others, the exhaust port does not have to be installed on the ground side.

[0038] Next, the operation of the safety valve 130 in this embodiment will be described.

[0039] Referring to FIG. 3 , when the high-pressure tank is exposed to an abnormally high temperature above a predetermined temperature, the temperature sensor detects the temperature. Based on this, a current flows from a power source (not shown) to the igniter 134 via the wiring 141 in response to a command from the control unit, activating the igniter 134. The flame generated by the activation of the igniter 134 is received by the receiving portion 144b of the piston member 144. The piston member 144, receiving the energy of the flame, moves toward the openable portion 132 along the penetration direction of the hole 142a. The tip of the rod-shaped portion 144a of the piston member 144 then splits or breaks the openable portion 132, forming the hole 132a. At this time, the heat-reducing and flame-extinguishing agent 145 reduces the heat of the flame and extinguishes any excess flame. After the hole 132a is formed in the openable portion 132, the piston member 144 is pushed back toward the internal space 131B by the pressure of the gas inside the tank body. As a result, the internal space 131B and the hole 131C communicate with each other through the hole 132a (see FIG. 3B). The communication between the internal space 131B and the hole 131C allows the gas filling the internal space of the tank body 110 to be discharged to the external environment through a flow path formed by the hole 131C, the hole 132a, the internal space 131B, and the discharge port 133.

[0040] According to the safety valve 130 having the above-described configuration, it is possible to achieve the same effects as those of the first embodiment.

[0041] Third Embodiment Next, a third embodiment of the present invention will be described in detail with reference to Fig. 4. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiment are similar, and therefore description thereof will be omitted unless otherwise specified.

[0042] As shown in FIG. 4, the safety valve 230 differs from the safety valve 30 of the first embodiment mainly in that it uses a main body 231 made up of multiple members, that it uses an ignition charge 234A and an auto-ignition agent (AI agent) 234B as opening means 234 instead of an igniter, and that a filter 238 is provided at the outlet 233.

[0043] The main body 231 includes a first member 231a having a recessed cross section, a substantially plate-shaped second member 231b, and a third member 231c having a substantially T-shaped cross section. An internal space 248 in which the piston member 244 can move after actuation and a discharge port 233 are formed inside the first member 231a. A recess 231B1 is formed in the center of the second member 231b on the third member 231c side, and a recess 231C1 is formed in the center of the third member 231c on the second member 231b side. Between recess 231B1 and recess 231C1 are provided a cylindrical member 242, an AI agent 234B arranged on the recess 231B1 side of cylindrical member 242, an ignition charge 234A arranged on the recess 231C1 side of AI agent 234B, and a piston member 244 that sandwiches ignition charge 234A and AI agent 234B together with openable portion 232B. A heat reducing and flame quenching agent 45 (an example of flame quenching means) is filled between the inner wall of cylindrical member 242 and the surface of rod-shaped portion 244a of piston member 244, and an O-ring 243 seals so that heat reducing and flame quenching agent 245 does not leak from hole 242a to the outside of cylindrical member 242. Either the ignition charge 234A or the AI ​​agent 234B may be disposed on the recess 231C1 side. Furthermore, the ignition charge 234A may be contained within the AI ​​agent 234B, or the AI ​​agent 234B may be disposed alone. Furthermore, the opposing surfaces of the second member 231b and the third member 231c are provided with ring-shaped recesses 231B2 and 231C2 for disposing the seal member 237 between the second member 231b and the third member 231c. Furthermore, a gap (clearance) is provided between the receiving portion 244b of the piston member 244 and the inner wall of the cylindrical member 242. As a result, when the piston member 244 slides toward the recess 231C1 after actuation, a portion of the heat reducing and flame suppressing agent 245 is pushed out of the gap toward the openable portion 232B from the state shown in FIG. 4(a) and moves toward the openable portion 232B of the cylindrical member 242 (see FIG. 4(b)).

[0044] The sealing member 237 may be, for example, an O-ring, a packing, or a gasket. The sealing member 237 may be made of fluororubber, styrene-based rubber, olefin-based rubber, or the like. Alternatively, the sealing member 237 may be sealed by applying an adhesive to it. Suitable adhesives include those containing, for example, cyanoacrylate resin, silicone resin, styrene-based rubber, or olefin-based rubber. The sealing member 237 may also be made of a metal containing at least one of stainless steel, copper, a copper alloy, aluminum, and an aluminum alloy.

[0045] Examples of the ignition charge 234A include ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), lead tricinate, and the like.

[0046] The AI ​​agent 234B is an explosive having an auto-ignition (AI) function, which automatically ignites in response to heat generated by a predetermined temperature that is lower than the ignition temperature of the ignition charge. Here, the AI ​​agent 234B is preferably one that automatically ignites at an ignition temperature of 230°C or lower, which is lower than the temperature at which the high-pressure tank bursts, and further preferably one that automatically ignites at an ignition temperature of 200°C or lower, taking into account thermal conductivity and the distance to the heat source. Note that, for example, the AI ​​agent 234B preferably contains the following component (A) or (B):

[0047] (A) An AI agent formed by binding a fuel component, an oxidizer, and a combustion modifier with a binder. Here, an example of the fuel component is a nitrogen-containing organic substance consisting of aminotetrazole or its salt. An example of the oxidizer is one containing 50% by weight or more of nitrate. An example of the combustion modifier is molybdenum, iron, or oxides thereof. An example of the binder is one selected from the following groups (1), (2), and (3). (1) A hydrotalcite-type compound represented by the following general formula [M 2+ 1-x M 3+ x (OH) x+ [A n- x / n ・mH2Ox- Here, M 2+ : Mg 2+ , Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ Divalent metals such as M 3+ :Al 3+ , Fe 3+ , Cr 3+ , Co 3+ , In 3+ Trivalent metals such as A n- :OH - , F - , Cl - ,Br - , NO3 - , CO3 2- , SO4 2- , Fe(CN)6 3- , CH3COO - , oxalate ion, salicylate ion, or other n-valent anion, x: 0<x≦0.33 (2) Acid clay (3) Polymer binder: The polymer binder improves the breaking strength and other mechanical properties when forming the desired explosive into a molded body. Specific examples of this polymer binder include metal salts of carboxymethylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, nitrocellulose, guar gum, polyvinyl alcohol, polyacrylamide, polysaccharide derivatives such as starch, and organic binders such as stearates, fluororubbers, and SBS rubber. These polymer binders may be used alone or in combination.

[0048] (B) An AI agent containing the following components in various composition ratios: (a) 3 to 25 (wt%) of 5-aminotetrazole, (b) 5 to 30 (wt%) of boron, (c) 50 to 85 (wt%) of potassium nitrate, and (d) 0.2 to 10 (wt%) of molybdenum trioxide, and having a calorific value of 4,500 J / g or more.

[0049] Here, as a modified example, an AI agent may be combined with a gas generating agent as needed (the gas generating agent is burned by the automatic ignition function of the AI ​​agent to generate gas). By combining an AI agent with a gas generating agent, the releasable portion can be opened more quickly upon activation. Furthermore, if the filling pressure of the fluid filled in the high-pressure tank is high, the strength of the releasable portion must also be set high, so in order to instantly open the releasable portion upon activation, it is necessary to combine the AI ​​agent with a gas generating agent. This modified example can also be applied to embodiments and modified examples that use other AI agents.

[0050] The gas generating agent is composed of an appropriate combination of a fuel and an oxidizer. The fuel component is one or more selected from the group consisting of guanidine derivatives, tetrazole derivatives, urea derivatives, triazole derivatives, hydrazine derivatives, triazine derivatives, and azodicarbonamide. The oxidizer component is one or more selected from the group consisting of metal oxides, chlorates, perchlorates, nitrates, basic nitrates, and basic carbonates. If necessary, the agent may also contain a burning rate modifier and a binder.

[0051] Next, the operation of the safety valve 230 in this embodiment will be described.

[0052] Referring to FIG. 4( a), when the high-pressure tank is exposed to an abnormally high temperature equal to or higher than a predetermined temperature lower than the burst temperature, the AI ​​agent 234B automatically ignites in response to the heat generated by the temperature, and the ignition charge 234A burns, activating the opening means 234. The flame generated by the activation of the opening means 234 is received by the receiving portion 244b of the piston member 244, and the piston member 244, receiving the energy of the flame, moves toward the openable portion 232A. Then, the tip of the rod-shaped portion 244a of the piston member 244 splits or breaks the openable portion 232A, forming a hole 232A1 (see FIG. 4( b)). At this time, the openable portion 232B is also opened (a hole 232B1 is formed at the bottom of the recess 231B1 by melting, splitting, or breaking, etc.) (see FIG. 4( b)), and the heat-reducing and flame-extinguishing agent 45 reduces the heat of the flame and extinguishes any excess flame. Subsequently, after holes 232A1 and 232B1 are formed in openable portions 232A and 232B, respectively, piston member 244 is pushed back to internal space 248 by the pressure of the gas inside tank body 210. As a result, exhaust port 233 and hole 231C communicate with each other via hole 232A1, hole 242a, the interior of tubular member 242, hole 232B1, and internal space 248. By connecting exhaust port 233 to hole 131C, the gas filling the internal space of tank body 210 is discharged to the external environment via a flow path formed by hole 131C, hole 232A1 formed in the bottom of recess 231C1, recess 231C1, recess 231B1, hole 232B1 formed in the bottom of recess 231B1, and exhaust port 233. A filter 238 may be disposed in exhaust port 233, if necessary. The filter 238 has the function of collecting residues generated when the ignition charge 234A and the AI ​​agent 234B are burned, and of absorbing heat from the generated gas to cool and extinguish the flame. Furthermore, even if the heat-reducing and flame-extinguishing agent 245 remains after activation, it can be collected by the filter 238.

[0053] The above configuration can achieve the same effects as the first embodiment. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 230 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when the vehicle is stopped and no current is being supplied to the control and sensors, the safety valve 230 can detect a fire (detect an abnormality) and operate safely.

[0054] <Fourth Embodiment> Next, a fourth embodiment of the present invention will be described in detail with reference to Fig. 5. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiment are similar, and therefore description thereof will be omitted unless otherwise specified.

[0055] As shown in FIG. 5 , the safety valve 330 differs from the safety valve 30 of the first embodiment mainly in that it uses a power generation unit 350 as a current supply source to the igniter 334, that wiring 341 is provided for transmitting the current generated in the power generation unit 350, that a fixing member 336 is provided inside the power generation unit 350 and inside the tubular member 342, and that the igniter 334 is provided inside the tubular member 342.

[0056] The power generating unit 350 includes an inner first metal layer 351, a middle semiconductor layer 352, and an outer second metal layer 353, with the semiconductor layer 352 sandwiched between the first metal layer 351 and the second metal layer 353. The power generating unit 350 may be formed by laminating two or more semiconductor materials with different Seebeck coefficients in layers, as long as it can generate current when exposed to an abnormally high temperature above a predetermined temperature. The Seebeck coefficient generally refers to the proportionality coefficient between a temperature difference and a voltage, which is generated when a temperature difference occurs across both ends of a metal and a semiconductor. Examples of combinations of two types of semiconductors include n-type and p-type semiconductors. When selecting two or more types of metals and semiconductors, materials with different Seebeck coefficients can be appropriately selected from the materials listed for the combinations of two types of metals and the combinations of two types of semiconductors described above. Examples of combinations of two types of metals include iridium and rhodium, platinum and rhodium, copper and constantan, iron and constantan, copper and iron, gold and platinum, nickel and molybdenum, tungsten and rhenium, gold and palladium, platinum and palladium, etc. Furthermore, the power generation unit 350 may be made of only one type of metal, which can obtain the Seebeck effect by being arranged so that a temperature difference (temperature gradient) occurs between the outside and inside when the outside becomes abnormally high temperature.

[0057] Next, the operation of the safety valve 330 in this embodiment will be described.

[0058] Referring to FIG. 5 , when the high-pressure tank is exposed to an abnormally high temperature above a predetermined temperature, current flows from the power generating unit 350 to the igniter 334 via the wiring 341, activating the igniter 334. The flame generated by the activation of the igniter 334 is received by the receiving portion 344b of the piston member 344, and the piston member 344, receiving the energy of the flame, moves toward the openable portion 332. The tip of the rod-shaped portion 344a of the piston member 344 then splits or breaks the openable portion 332, forming a hole. At this time, the heat-reducing and flame-extinguishing agent 345 reduces the heat of the flame and extinguishes any excess flame. After the hole is formed in the openable portion 332, the piston member 344 is pushed back toward the internal space 331B by the pressure of the gas inside the tank body. This establishes communication between the internal space 331B and the hole 331C through the hole. By connecting the internal space 331B and the hole 331C, the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole 331C, the internal space 331B, and the exhaust port 333.

[0059] The above configuration can achieve the same effects as the first embodiment. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 330 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when the vehicle is stopped and no current is being supplied to the control and sensors, the safety valve 330 can detect a fire (detect an abnormality) and operate safely.

[0060] Fifth Embodiment Next, a fifth embodiment of the present invention will be described in detail with reference to Fig. 6. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiment are similar, and therefore description thereof will be omitted unless otherwise specified.

[0061] As shown in FIG. 6, the safety valve 430 differs from the safety valve 30 of the first embodiment mainly in that an opening means 434 is used instead of an igniter.

[0062] The opening means 434 is provided inside the cylindrical member 442 and includes a plate-shaped base 434A having a piston function, a pin member 434C (protrusion), and an AI agent 434B. The plate-shaped base 434A is movable along the inner wall of the cylindrical member 442 and is attached to the openable portion 432 side of the AI ​​agent 434B. The pin member 434C is fixed to the openable portion 432 side of the plate-shaped base 434A and is a member with a pointed tip. The pin member 434C is also provided so as to pass through a hole 442a provided in the bottom of the cylindrical member 442. A gap (clearance) is provided between the plate-shaped base 434A and the inner wall of the cylindrical member 442. As a result, when the plate-shaped base 434A and the pin member 434C slide toward the recess 431C1 after activation, a portion of the heat-reducing and flame-reducing agent 445 is pushed out from the gap toward the AI ​​agent 434B from the state shown in Figure 6 and moves to the AI ​​agent 434B side of the cylindrical member 442.

[0063] Next, the operation of the safety valve 430 in this embodiment will be described.

[0064] Referring to FIG. 6 , when the high-pressure tank is exposed to an abnormally high temperature equal to or higher than a predetermined temperature lower than the burst temperature, the AI ​​agent 434B automatically ignites in response to the heat generated by the temperature. The pressure wave (including static pressure and dynamic pressure) generated by the AI ​​agent 434B automatically ignites moves the plate-shaped base 434A toward the openable portion 432, and the pin member 434C opens the openable portion 432 (forming a hole by splitting or breaking, etc.). At this time, the heat-reducing and flame-extinguishing agent 445 reduces the heat of the flame caused by the ignition of the AI ​​agent 434B and extinguishes any excess flame. Subsequently, after the hole is formed in the openable portion 432, the plate-shaped base 434A and the pin member 434C are pushed back toward the internal space 431B by the pressure of the gas inside the tank body. This establishes communication between the internal space 431B and the hole 431C through the hole. By connecting the internal space 431B and the hole 431C, the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole 431C, the internal space 431B, and the exhaust port 433.

[0065] The above configuration can achieve the same effects as the first embodiment. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 430 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when the vehicle is stopped and no current is being supplied to the control and sensors, the safety valve 430 can detect a fire (detect an abnormality) and operate safely.

[0066] Sixth Embodiment Next, a sixth embodiment of the present invention will be described in detail with reference to Fig. 7. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiments are similar, and therefore description thereof will be omitted unless otherwise specified.

[0067] As shown in FIG. 7 , safety valve 530 differs from safety valve 30 of the first embodiment mainly in that it uses fixed member 536 having cylindrical cylinder portion 536a whose inner wall is in contact with the periphery of receiving portion 544b, and in that it uses piston member 544 having rod-shaped portion 544a with an expanded diameter portion 544c at the tip end of rod-shaped portion 544a whose diameter is larger than that of rod-shaped portion 544a. Also, a gap (clearance) is provided between receiving portion 544b of piston member 544 and the inner wall of cylindrical member 542. As a result, when piston member 544 slides toward recess 531C1 after actuation, a portion of heat-reducing and flame-reducing agent 545 is pushed out of the gap toward igniter 534 from the state shown in FIG. 7( a) and moves toward igniter 534 of cylindrical member 542 (see FIG. 7( b)).

[0068] Next, the operation of the safety valve 530 in this embodiment will be described.

[0069] Referring to FIG. 7 , when the high-pressure tank is exposed to an abnormally high temperature above a predetermined temperature, a temperature sensor (not shown) detects the temperature. Based on this, a current flows from a power source (not shown) to igniter 534 via wiring 541 in response to a command from the control unit, activating igniter 534. The pressure wave (including static pressure and dynamic pressure) generated by activation of igniter 534 causes piston member 544 to slide toward releasable portion 532 inside cylinder portion 536a. Subsequently, enlarged diameter portion 544c of piston member 544 opens releasable portion 532 (forming hole 532a by cleavage or fracture, etc.), connecting internal space 531B and hole 531C (see FIG. 7(b)). At this time, heat-reducing and flame-extinguishing agent 545 reduces the heat of the flame generated by activation of igniter 534 and extinguishes any excess flame. In this way, the internal space 531B and the hole 531C are connected, and the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole 531C, the internal space 531B, and the exhaust port 533.

[0070] The above configuration can achieve the same effects as those of the first embodiment.

[0071] Seventh Embodiment Next, a seventh embodiment of the present invention will be described in detail with reference to Fig. 8. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiment are similar, and therefore description thereof will be omitted unless otherwise specified.

[0072] As shown in the initial state diagram of Figure 8(a), safety valve 630 differs from safety valve 30 of the first embodiment mainly in that openable portion 632, which is the bottom portion that closes hole portion 631C, is formed by closing using the flat surface (lower surface in Figure 8(a)) of head portion 644c of piston member 644 and sealing member 650, that piston member 644 is arranged to slide within internal space 631B due to pressure waves (including static pressure and dynamic pressure) when igniter 634 is activated, that plate-shaped member 646 is adhesively fixed to the side of main body portion 631, and that igniter 634 is fixed and held at the other end of fixing member 636 with one end of fixing member 636 abutting against plate-shaped member 646. As shown in FIG. 8( a), the head portion 644c of the piston member 644 is pressed toward the seal member 650 by the bolt member 660 threaded into the through-hole 651, thereby providing a sufficient seal for the high-pressure gas. The internal space 631B and the hole 631C are not in communication with each other in the initial state. The bolt member 660 has an outlet 633 formed therein, which is in communication with the outside. When the piston member 644 is in the state shown in FIG. 8( b), the internal space 631B communicates with the outside via the outlet 633. When the head portion 644c of the piston member 644 is pressed toward the seal member 650 by the bolt member 660, the fixing member 636 and the cylindrical member 442 are movable within the main body 631 along the axial direction of the bolt member 660 in accordance with the movement of the head portion 644c.

[0073] Next, the operation of the safety valve 630 in this embodiment will be described.

[0074] Referring to Figure 8(a), when the high-pressure tank is exposed to an abnormally high temperature equal to or higher than a predetermined temperature, a temperature sensor (not shown) detects the temperature, and based on this, a command from the control unit described above causes a current to flow from a power source (not shown) to igniter 634 via wiring 641, activating igniter 634. A pressure wave (including static pressure and dynamic pressure) generated by activation of igniter 634 causes piston member 644 to slide in internal space 631B toward the side opposite igniter 634. At this time, heat-reducing and flame-extinguishing agent 645 reduces the heat of the flame caused by activation of igniter 634 and extinguishes any excess flame. As a result, openable portion 632 formed by piston member 644 and seal member 650 is opened, and internal space 631B and hole 631C communicate with each other (see Figure 8(b)). In this way, the internal space 631B and the hole 631C are connected, and the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole 631C, the internal space 631B around the rod-shaped portion 644a in Figure 8 (b), and the exhaust port 633.

[0075] The above configuration can achieve the same effects as those of the first embodiment.

[0076] Eighth Embodiment Next, an eighth embodiment of the present invention will be described in detail with reference to Fig. 9. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiments are similar, and therefore description thereof will be omitted unless otherwise specified.

[0077] As shown in FIG. 9 , safety valve 730 differs from safety valve 30 of the first embodiment mainly in that it uses power generation unit 750 as a current supply source to igniter 734, that wiring 741 is provided for transmitting the current generated in power generation unit 750, that a fixing member 736 is provided in a part of power generation unit 750 to support igniter 734, that an internal space 731B is formed by main body portion 731 and lid portion 737, that fixing member 736 is provided inside tubular member 742, and that igniter 734 is provided inside tubular member 742.

[0078] The power generating unit 750 includes a first semiconductor 752A, a second semiconductor 752B, and conductive members 754, 755A, and 755B. For example, the first semiconductor 752A is an n-type semiconductor, and the second semiconductor 752B is a p-type semiconductor.

[0079] One end (outer end) of the first semiconductor 752A and one end (outer end) of the second semiconductor 752B are electrically connected via a conductive member 754. The other end of the first semiconductor 752A is electrically connected to one terminal pin 735 via a conductive member 755A and one wiring 741. The other end of the second semiconductor 752B is electrically connected to the other terminal pin 735 via a conductive member 755B and the other wiring 741. The conductive members 755A and 755B are each fixed to the inner wall of the main body 731 with an adhesive such as resin while being electrically insulated from the main body 731.

[0080] Internal space 731B is formed by being surrounded by main body 731 having a recess in the center and lid 737 provided to close the recess. Main body 731 and lid 737 also function as protective parts that protect the other end sides (igniter 734 sides) of first semiconductor 752A and second semiconductor 752B from external heat.

[0081] Furthermore, the first semiconductor 752A and the second semiconductor 752B of the power generation unit 750 are provided so as to pass through through-holes 737a and 737b provided in the lid unit 737. Although not shown, the through-holes 737a and 737b are closed by the first semiconductor 752A and the second semiconductor 752B and a resin or the like to prevent gas from leaking out. Furthermore, the first semiconductor 752A and the second semiconductor 752B are electrically insulated from the through-holes 737a and 737b.

[0082] The igniter 734 is supported by a fixing member 736 fixed to the igniter 734 side of the conductive members 755A and 755B.

[0083] Next, the operation of the safety valve 730 in this embodiment will be described.

[0084] 9 , when the high-pressure tank is exposed to an abnormally high temperature above a predetermined temperature, a temperature difference occurs between the outer portions of the first semiconductor 752A and the second semiconductor 752B and the portions of the first semiconductor 752A and the second semiconductor 752B facing the internal space 731B. This causes a current to flow from the power generating unit 750 to the igniter 734 via the wiring 741 due to the Seebeck effect, activating the igniter 734. The flame generated by the activation of the igniter 734 is received by the receiving portion 744b of the piston member 744, and the piston member 744, receiving the energy of the flame, moves toward the openable portion 732. The tip of the rod-shaped portion 744a of the piston member 744 then splits or breaks the openable portion 732, forming a hole. At this time, the heat-reducing and flame-extinguishing agent 745 reduces the heat of the flame and extinguishes any excess flame. Subsequently, after the hole is formed in the releasable portion 732, the piston member 744 is pushed back toward the internal space 731B by the pressure of the gas inside the tank body. As a result, the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole, the internal space 731B, and the exhaust port 733. If necessary, a filter circuit using a transistor protection circuit or a diode may be connected between the wiring 741 and the igniter 734 in order to block current below a certain current value. This makes it possible to prevent malfunction in unintended situations.

[0085] The above configuration can achieve the same effects as the first embodiment. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 730 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when the vehicle is stopped and no current is being supplied to the control and sensors, the safety valve 730 can detect a fire (detect an abnormality) and operate safely.

[0086] Ninth Embodiment Next, a ninth embodiment of the present invention will be described in detail with reference to Fig. 10. The high-pressure tank of this embodiment is substantially the same as that of the first or eighth embodiment, and therefore, unless otherwise specified, the description and illustration of similar parts will be omitted. Furthermore, parts having the same last two digits as those of the above-described embodiments will be omitted unless otherwise specified, as they are similar.

[0087] 10 , safety valve 830 differs from safety valve 730 of the eighth embodiment mainly in that it uses power generating unit 850 provided separately from main body 831 as a current supply source to igniter 834. Safety valve 830 also differs from safety valve 30 of the first embodiment in that it uses power generating unit 850 instead of power source 40 (such as a battery) of the first embodiment, that a fixing member 836 is provided inside cylindrical member 842, and that igniter 834 is provided inside cylindrical member 842.

[0088] The power generating unit 850 includes a first semiconductor 852A, a second semiconductor 852B, conductive members 854, 855A, and 855B, and a box-shaped protective unit 837. The protective unit 837 provides protection from external heat and is made of the same material as the main body 831 or a heat-resistant material.

[0089] One end (outer end) of the first semiconductor 852A and one end (outer end) of the second semiconductor 852B are electrically connected via a conductive member 854. The other end of the first semiconductor 852A is electrically connected to one terminal pin 835 via a conductive member 855A and one wiring 841. The other end of the second semiconductor 852B is electrically connected to the other terminal pin 835 via a conductive member 855B and the other wiring 841. Each of the conductive members 855A and 855B is fixed to the inner wall of the protective portion 837 with an adhesive such as resin.

[0090] Furthermore, the first semiconductor 852A and the second semiconductor 852B of the power generation unit 850 are provided so as to pass through through holes 837a and 837b, respectively, provided on the upper side of the protective unit 837. Although not shown, the through holes 837a and 837b are blocked by the first semiconductor 852A and the second semiconductor 852B and a resin or the like. Furthermore, the first semiconductor 852A and the second semiconductor 852B are electrically insulated from the through holes 837a and 837b.

[0091] Next, the operation of the safety valve 830 in this embodiment will be described.

[0092] 10 , when power generating unit 850 is exposed to an abnormally high temperature above a predetermined temperature, a temperature difference occurs between the outer portions of first semiconductor 852A and second semiconductor 852B and the portions of first semiconductor 852A and second semiconductor 852B facing internal space 837A. Due to the Seebeck effect, a current flows from power generating unit 850 to igniter 834 via wiring 841, activating igniter 834. The flame generated by activation of igniter 834 is received by receiving portion 844b of piston member 844, and piston member 844, receiving the energy of the flame, moves toward openable portion 832. Then, the tip of rod-shaped portion 844a of piston member 844 splits or breaks openable portion 832, forming a hole. At this time, heat-reducing and flame-extinguishing agent 845 reduces the heat of the flame and extinguishes any excess flame. Subsequently, after the hole is formed in the releasable portion 832, the piston member 844 is pushed back toward the internal space 831B by the pressure of the gas inside the tank body. As a result, the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole, the internal space 831B, and the exhaust port 833. If necessary, a filter circuit using a transistor protection circuit or a diode may be connected between the wiring 841 and the igniter 834 in order to block current below a certain current value. This makes it possible to prevent malfunction in unintended situations.

[0093] The above configuration can achieve the same effects as those of the first and eighth embodiments. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 830 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when the vehicle is stopped and no current is being supplied to the control and sensors, the safety valve 830 can detect a fire (detect an abnormality) and operate safely.

[0094] Tenth Embodiment Next, a tenth embodiment of the present invention will be described in detail with reference to Fig. 11. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiments are similar, and therefore description thereof will be omitted unless otherwise specified.

[0095] As shown in FIG. 11 , the safety valve 930 differs from the safety valve 30 of the first embodiment mainly in that it uses a power generating unit 950 as a current supply source to the igniter 934, that wiring 941 is provided for transmitting the current generated in the power generating unit 950, that a fixing member 936 is provided on the internal space 931B side of the power generating unit 950, that the fixing member 936 is provided inside the tubular member 942, and that the igniter 934 is provided inside the tubular member 942.

[0096] The power generation unit 950 is made of the same metal and includes a first portion 951 provided on the outside, a second portion 952 provided on the inside so as to face the first portion 951, and a connection portion 953 that electrically connects an end of the first portion 951 to an end of the second portion 952. The second portion 952 has a protrusion 952A on the side facing the internal space 931B, and the power generation unit 950 functions as a heat sink.

[0097] The internal space 931B is formed by being surrounded by the main body 931 having a recess in the center and the power generation unit 950 provided to close the recess. The main body 931 and the power generation unit 950 also function as a protective unit that protects the second unit 952 from external heat.

[0098] Next, the operation of the safety valve 930 in this embodiment will be described.

[0099] Referring to FIG. 11 , when the high-pressure tank is exposed to an abnormally high temperature above a predetermined temperature, a temperature difference occurs between the first portion 951 and the second portion 952. Due to the Seebeck effect, an electric current flows from the power generating unit 950 to the igniter 934 via the wiring 941, activating the igniter 934. The flame generated by the activation of the igniter 934 is received by the receiving portion 944b of the piston member 944. The piston member 944, receiving the energy of the flame, moves toward the openable portion 932. The tip of the rod-shaped portion 944a of the piston member 944 then splits or breaks the openable portion 932, forming a hole. At this time, the heat-reducing and flame-extinguishing agent 945 reduces the heat of the flame and extinguishes any excess flame. After the hole is formed in the openable portion 932, the piston member 944 is pushed back toward the internal space 931B by the pressure of the gas inside the tank body. As a result, the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole, the internal space 931B, and the exhaust port 933. If necessary, a filter circuit using a transistor protection circuit or a diode or the like may be connected between the wiring 941 and the igniter 934 in order to block current below a certain value. This makes it possible to prevent malfunction in unintended circumstances.

[0100] The above configuration can achieve the same effects as those of the first embodiment. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 930 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when no current is supplied to the control or sensor, such as when the vehicle is stopped, the safety valve 930 can detect a fire (detect an abnormality) and operate safely.

[0101] Eleventh Embodiment Next, an eleventh embodiment of the present invention will be described in detail with reference to Fig. 12. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiment are similar, and therefore description thereof will be omitted unless otherwise specified.

[0102] 12 , the safety valve 1030 differs from the safety valve 30 of the first embodiment mainly in that it uses a power generating unit 1050 as a current supply source to the igniter 1034, that wiring 1041 is provided for transmitting the current generated in the power generating unit 1050, that a fixing member 936 is provided on the internal space 1031B side of the power generating unit 1050, that the fixing member 1036 is provided inside the cylindrical member 1042, and that the igniter 1034 is provided inside the cylindrical member 1042. Furthermore, the safety valve 1030 differs from the safety valve 930 of the tenth embodiment mainly in that it uses a power generating unit 850 having a portion (first portion 1051 described later) provided separate from the main body portion 1031 as a current supply source to the igniter 1034, as shown in FIG.

[0103] The power generation unit 1050 is made of the same metal and includes a first portion 1051, a second portion 1052, and a connecting portion 1053. The first portion 1051 is provided separate from the main body portion 1031, and the second portion 1052 is electrically connected to the first portion 1051 via the connecting portion 1053. The second portion 1052 has a protrusion 1052A on the outer side, and the power generation unit 1050 functions as a heat sink. The protrusion 1052A may be provided on the inner side of the main body portion 1031.

[0104] Internal space 1031B is formed by being surrounded by main body 1031 having a recess in the center and second part 1052 of power generating unit 1050 provided to close the recess. In addition, fixing member 1036 is provided on the igniter 1034 side of second part 1052 and supports igniter 1034.

[0105] Next, the operation of the safety valve 1030 in this embodiment will be described.

[0106] 12 , when first portion 1051 is exposed to an abnormally high temperature above a predetermined temperature, a temperature difference occurs between first portion 1051 and second portion 1052, and the Seebeck effect causes current to flow from power generating portion 1050 to igniter 1034 via wiring 1041, activating igniter 1034. The flame generated by activation of igniter 1034 is received by receiving portion 1044b of piston member 1044, and piston member 1044, receiving the energy of the flame, moves toward openable portion 1032. Then, the tip of rod-shaped portion 1044a of piston member 1044 splits or breaks openable portion 1032, forming a hole. At this time, heat-reducing and flame-extinguishing agent 1045 reduces the heat of the flame and extinguishes any excess flame. Subsequently, after the hole is formed in the releasable portion 1032, the piston member 1044 is pushed back toward the internal space 1031B by the pressure of the gas inside the tank body. As a result, the gas filled in the tank body is discharged to the external environment through the flow path formed by the hole, the internal space 1031B, and the exhaust port 1033. If necessary, a filter circuit using a transistor protection circuit or a diode or the like may be connected between the wiring 1041 and the igniter 1034 in order to cut off current below a certain current value. This makes it possible to prevent malfunction in unintended circumstances.

[0107] The above configuration can achieve the same effects as those of the first embodiment. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 1030 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when the vehicle is stopped and no current is being supplied to the control and sensors, the safety valve 1030 can detect a fire (detect an abnormality) and operate safely.

[0108] <Twelfth Embodiment> Next, a twelfth embodiment of the present invention will be described in detail with reference to Fig. 13. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiment are similar, and therefore description thereof will be omitted unless otherwise specified.

[0109] The vehicle 1100 includes a vehicle body 1101 and a high-pressure tank 1102 attached to the center of the lower part of the vehicle body 1101. The high-pressure tank 1102 has a tank main body 1103. Although not shown, the tank main body 1103 is provided with a plurality of safety valves similar to the safety valve 830 shown in the ninth embodiment or the safety valve 1030 shown in the eleventh embodiment.

[0110] The safety valve has an igniter (not shown), power generation units 1150A and 1150B, and wiring 1141A and 1141B. Power generation unit 1150A is provided in the front portion of the lower part of vehicle body 1101, and power generation unit 1150B is provided in the rear portion of the lower part of vehicle body 1101. As in the case of safety valve 830 or safety valve 1030, power generation units 1150A and 1150B are electrically connected to the igniter via wiring 1141A and 1141B. In other words, power generation units 1150A and 1150B are provided at a distance from the main body of the safety valve, etc.

[0111] Next, the operation of the safety valve in this embodiment will be described. For convenience, the operation of a vehicle 1100 using the safety valve 1030 of the eleventh embodiment will be described as an example.

[0112] Referring to FIG. 13 , when the power generating unit 1150A or 1150B of the vehicle 1100 is exposed to an abnormally high temperature above a predetermined temperature, a temperature difference occurs between the first section 1051 and the second section 1052. Due to the Seebeck effect, a current flows from the power generating unit 1050 to the igniter 1034 via the wiring 1041. As in the eleventh embodiment, the igniter 1034 is activated. Referring to FIG. 12 , a flame generated by the activation of the igniter 1034 is received by the receiving portion 1044b of the piston member 1044. The piston member 1044 receives the energy of the flame and moves toward the openable portion 1032. Then, the tip of the rod-shaped portion 1044a of the piston member 1044 splits or breaks the openable portion 1032, forming a hole. At this time, the heat-reducing and flame-extinguishing agent 1045 reduces the heat of the flame and extinguishes any excess flame. Subsequently, after the hole is formed in the openable portion 1032, the piston member 1044 is pushed back toward the internal space 1031B by the pressure of the gas inside the tank body 1103. As a result, the gas that had been filled in the tank body 1103 is discharged to the external environment via the flow path formed by the hole, the internal space 1031B, and the discharge port 1033.

[0113] The above configuration can achieve the same effects as those of the first embodiment. Furthermore, since an external power source such as the power source 40 is not required, the safety valve 1030 can be made lighter than when the safety valve 30 of the first embodiment is used. Furthermore, even when the vehicle is stopped and no current is being supplied to the control and sensors, the safety valve 1030 can detect a fire (detect an abnormality) and operate safely.

[0114] In addition to the power generating units 1150A and 1150B, another power generating unit similar to the power generating units 1150A and 1150B may be provided at any location on the vehicle body, and the other power generating unit may be electrically connected to the igniter via wiring.

[0115] <Thirteenth Embodiment> Next, a thirteenth embodiment of the present invention will be described in detail with reference to Fig. 14. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiments are similar, and therefore description thereof will be omitted unless otherwise specified.

[0116] As shown in Figure 14, the safety valve 1230 differs from the safety valve 30 of the first embodiment mainly in that a flame-extinguishing member 1247 is provided inside the bottom of the cylindrical member 1242 instead of the heat-reducing and flame-extinguishing agent 45 in the first embodiment.

[0117] Flame quenching member 1247 has a central hole 1247a through which 1244a passes. Flame quenching member 1247 may be, for example, a metal crimp ribbon (a spiral formed by alternating pleated and flat metal plates, resulting in many tiny triangular cross-sectional spaces), a metal mesh material made from metal netting or wire, a sintered metal (porous metal), or an O-ring or other flame-quenching member (commonly referred to as a flame arrester). Here, the O-ring may have grease applied to its surface (preferably silicone grease or heat-resistant grease for flame resistance) if necessary.

[0118] With the above-described configuration, the safety valve 1230 of this embodiment can achieve the same effects as those of the first embodiment.

[0119] In other embodiments, as in this embodiment, a material similar to the flame quenching member 1247 can be used instead of the heat reducing and flame extinguishing agent. The flame quenching member may be disposed at any position inside the cylindrical member as long as it can perform its flame quenching function and does not interfere with the movement of the piston member during operation. A flame quenching agent may also be disposed in at least a portion of the cylindrical member 1242 to extinguish a flame generated by the igniter or AI agent during operation. In other words, the flame quenching member and the flame extinguishing agent may be used as a safety valve to extinguish a flame generated during operation.

[0120] <Fourteenth Embodiment> Next, a fourteenth embodiment of the present invention will be described in detail with reference to Fig. 15. The high-pressure tank of this embodiment is substantially the same as that of the first embodiment, and therefore, description and illustration of similar parts will be omitted unless otherwise specified. Furthermore, parts having the same last two digits as those of the above-described embodiments are similar, and therefore description thereof will be omitted unless otherwise specified.

[0121] As shown in FIG. 15, the safety valve 1330 differs from the safety valve 30 of the first embodiment mainly in that a bottomed cylindrical member 1342 without a hole in the bottom is used instead of the cylindrical member 42 of the first embodiment.

[0122] When the safety valve 1330 is activated, the bottom 1342A of the cylindrical member 1342 is opened (split or broken) by the tip of the rod-shaped portion 1344a of the piston member 1344. Furthermore, when the safety valve 1330 is activated, following the opening of the bottom 1342A of the cylindrical member 1342, the openable portion 1332 is opened (split or broken) by the tip of the rod-shaped portion 1344a of the piston member 1344.

[0123] With the above-described configuration, the safety valve 1330 in this embodiment can achieve the same effects as those in the first embodiment.

[0124] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and the like can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention.

[0125] For example, if the gas discharged from the outlet of the safety valve in each embodiment is a flammable gas, it is preferable that the gas be discharged toward the ground. Therefore, a pipe or the like may be provided at the outlet to restrict the discharge direction of the gas from the safety valve toward the ground. However, if the gas is not particularly flammable, the outlet may be provided facing any direction as long as it does not affect the human body.

[0126] Furthermore, the second member 231b and the third member 231c in the third embodiment may be formed of a material (e.g., an alloy of two or more metals, such as lead, tin, bismuth, indium, and antimony) that melts when the ambient temperature of the high-pressure tank becomes high (abnormally high) due to an external fire or the like. This weakens the second member 231b and the third member 231c when an external fire breaks out and heat is conducted through the second member 231b and the third member 231c, making it easier for the openable portions 232A and 232B to open (crack or break) when the safety valve 230 is activated. In this case, the openable portions 232A and 232B can be opened with a smaller amount of ignition charge 234A than in the third embodiment.

[0127] In addition, in the above-described embodiments, the safety valves are activated when an abnormally high temperature occurs, but this is not limiting. The safety valves may be activated by a command signal from an ECU (Electronic Control Unit) that is issued when an abnormality is detected by a sensor or the like. For example, the safety valves may be activated by a command signal output from the ECU when a collision is detected by a sensor or the like.

[0128] Furthermore, the shape of the power generating section that generates electricity by the Seebeck effect in the above embodiments and modified examples (especially the shape of those formed from a single type of metal) can be various shapes, such as layered, plate-shaped, rod-shaped, wire-shaped, etc., and combinations of these shapes.

[0129] In the tenth and eleventh embodiments, the power generating section is formed from one type of metal, but this is not limiting. For example, the power generating section may be formed by using metals with different Seebeck coefficients for the first and second sections.

[0130] For example, in each embodiment, the piston member breaks open the releasable portion of the safety valve on the tank body side when activated, but this is not limited to this. For example, instead of the piston member in each embodiment, the flame quenching member used in the thirteenth embodiment may be provided on the inside or outside of the bottom of the cylindrical member so as to cover the hole, or inside the hole, so that the flame of the igniter is extinguished when activated, and the pressure wave of the flame (extinguished) from the hole at the bottom alone breaks or breaks open the releasable portion of the safety valve on the tank body side, allowing the gas filled in the tank body to be discharged to the external environment.

[0131] The O-ring provided in the hole at the bottom of the cylindrical member may itself have a flame-extinguishing function, without using the flame-extinguishing agent in the first to twelfth embodiments or the flame-extinguishing member in the thirteenth embodiment. Here, the O-ring may have a surface coated with grease (preferably silicone grease or heat-resistant grease from the viewpoint of flame resistance) as needed.

[0132] Furthermore, the various parts of the above-described embodiment and modified examples may be combined as appropriate as necessary.

[0133] 10, 110, 210, 1103 Tank body 10a Space 11, 12, 112, 212 Opening 20 Valve 21 Supply port 30, 130, 230, 330, 430, 530, 630, 730, 830, 930, 1030, 1230, 1330 Safety valve 31, 131, 231, 331, 431, 531, 631, 731, 831, 931, 1031, 1231, 1331 Body 31A, 131A, 231A, 331A, 431A, 531A, 631A, 731A, 831A, 931A, 1031A, 1231A, 1331A Male threaded portion 31B, 131B, 238, 331B, 431B, 531B, 631B, 731B, 831B, 837A, 931B, 1031B, 1231B, 1331B Internal space 31C, 131C, 231C, 331C, 431C, 531C, 631C, 931C, 1031C, 1231C, 1331C Hole 32, 132, 232A, 232B, 332, 432, 532, 632, 732, 832, 932, 1032, 1232, 1332 Openable part 33, 133, 233, 333, 433, 533, 633, 733, 833, 933, 1033, 1233, 1333 Discharge port 34, 134, 334, 534, 634, 734, 834, 934, 1034, 1234, 1334 Igniter 35, 135, 335, 535, 635, 735, 835, 935, 1035, 1235, 1335 Terminal pin 36, 136, 336, 536, 736, 836, 936, 1036, 1236, 1336 Fixing member 40 Power supply 41, 141, 341, 541, 641, 741, 841, 941, 1041, 1141A, 1141B, 1241, 1341 Wiring 42, 142, 242, 342, 442, 542, 642, 742, 842, 942, 1042, 1242, 1342 Cylindrical member 234B, 434B AI agent 100, 1102 High-pressure tank 42a, 132a, 532a, 142a, 232A1, 232B1, 242a, 342a, 442a, 542a, 642a, 742a, 842a, 942a, 1042a, 1242a, 1247a Hole 43, 137, 143, 237, 243, 343, 443, 543, 643, 650, 743, 843, 943, 1043, 1243 O-ring44, 144, 244, 344, 444, 544, 644, 744, 844, 944, 1044, 1244, 1344 Piston member 44a, 144a, 244a, 344a, 444a, 544a, 644a, 744a, 844a, 944a, 1044a, 1244a, 1344a Rod-shaped portion 44b, 144b, 244b, 344b, 444b, 544b, 644b, 744b, 844b, 944b, 1044b, 1244b, 1344b Receiving portion 45, 145, 245, 345, 445, 545, 645, 745, 845, 945, 1045, 1245, 1345 Heat reducing and flame retardant 231B1, 231B2, 231C1, 231C2 Recess 231a First member 231b Second member 231c Third member 234, 434 Opening means 234A Ignition charge 238 Filter 350, 750, 850, 950, 1050, 1150A, 1150B Power generating section 351 First metal layer 352 Semiconductor layer 353 Second metal layer 434A Plate-shaped base 434C Pin member 536a Cylinder section 544c Expanded diameter section 651, 737a, 737b, 837a, 837b Through-hole 737 Lid portion 752A, 852A First semiconductor 752B, 852B Second semiconductor 754, 755A, 755B, 855A, 855B Conductive member 837 Protective portion 951, 1051 First portion 952, 1052 Second portion 953, 1053 Connection portion 1100 Vehicle 1101 Vehicle body 1342A Bottom portion

Claims

1. A safety valve for a high-pressure tank that can be connected to an opening of a tank body filled with a fluid, comprising: a main body having an outlet that comes into contact with the external environment and a flow path that connects the opening with the external environment via the outlet; and a valve that is provided at any position in the flow path, that normally closes the flow path and opens the flow path when an abnormally high temperature occurs or an abnormality is detected, wherein the valve has an openable portion that is opened by actuation of an opening means provided in the flow path, the opening means is provided in the flow path downstream of the openable portion and opens the openable portion using energy obtained by igniting explosives as a driving source, and the valve is provided with a flame extinguishing means for a flame generated by the ignition of the explosives when the opening means is actuated.

2. The explosive in the opening means is an igniter that is activated by the flow of an electric current, or an autoignition agent that automatically ignites at a predetermined temperature or above, and the flame quenching means is an extinguishing agent or flame quenching member that extinguishes a flame generated when the igniter or the autoignition agent is activated, and further comprising: a cylindrical member having the igniter or the autoignition agent disposed at one end and a bottom with a hole formed therein at the other end; and a piston member at least a portion of which is provided inside the cylindrical member and is provided so as to penetrate the hole in an initial state, and which slides in the penetrating direction of the hole by a pressure wave obtained by ignition of the igniter or automatic ignition of the autoignition agent when the igniter or the autoignition agent is activated, thereby opening the openable portion, and the flame quenching means is provided at least partially between the inner wall of the cylindrical member and the piston inside the cylindrical member.

3. The explosive in the opening means is an igniter that is activated by the flow of an electric current, or an autoignition agent that automatically ignites at a predetermined temperature or above, and the flame quenching means is an extinguishing agent or extinguishing member that extinguishes a flame generated when the igniter or the autoignition agent is activated, and further comprising: a cylindrical member having the igniter or the autoignition agent disposed at one end and having a bottom at the other end; and a piston member that is provided inside the cylindrical member and slides to the other end side of the cylindrical member by a pressure wave generated by ignition of the igniter or automatic ignition of the autoignition agent when the igniter or the autoignition agent is activated, thereby opening the bottom and the openable portion of the cylindrical member in sequence, and the flame quenching means is provided at least partially between the inner wall of the cylindrical member and the piston inside the cylindrical member.

4. The safety valve for a high-pressure tank as described in claim 1, characterized in that the explosive in the opening means is an igniter that is activated by the flow of an electric current, or an auto-ignition agent that automatically ignites at a predetermined temperature or above, the flame quenching means is a flame quenching member that extinguishes a flame generated when the igniter or the auto-ignition agent is activated, and the valve further comprises a cylindrical member having the igniter or the auto-ignition agent arranged at one end and having a bottom with a hole formed therein at the other end, the flame quenching member is arranged on the inside or outside of the cylindrical member or inside the hole so as to cover the hole, and the openable portion is ruptured or split open by a pressure wave obtained after the flame is extinguished by the flame quenching member.

5. A safety valve for a high-pressure tank as described in claim 4, characterized in that the flame quenching means further includes an anti-flame agent, the anti-flame agent being disposed within at least a portion of the interior of the tubular member, and the openable portion is ruptured or split open by a pressure wave obtained after the flame is extinguished by the anti-flame agent and the anti-flame agent.

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