Safety relief device and bottle valve

Abstract

The utility model relates to the field of safety valve of temperature is too high actuation, especially safety relief device and bottle valve. The bottle valve of the utility model improves prior art, especially has optimized safety relief device, through setting up after the delay section and opening the pressure balance passage that communicates the axial both ends of the relief valve core from the sealed section through the after delay section on the relief valve core, and through the design guarantees that the after delay section has the backside gas pressure-bearing surface area equal with the front side gas pressure-bearing surface of sealed section, can make the gas pressure balance that the relief valve core axial both ends suffer, namely the relief valve core does not receive the pressure of high pressure gas in the bottle, fusible alloy blocking piece is always only under the pressure of relief spring and is balanced and supported with relief spring on the both sides of relief valve core, avoided the problem that fusible alloy is under pressure and creep failure and poor reliability when the existing relief device is used for high pressure gas cylinder.

Description

Technical Field

[0001] This utility model relates to the field of safety valves that are actuated when the temperature is too high, and in particular to a safety relief device and a bottle valve. Background Technology

[0002] With the rapid development of the new energy vehicle market, hydrogen fuel cell vehicles represent an important direction for addressing the energy and environmental crises. The cylinder valve in the hydrogen supply system of a hydrogen fuel cell vehicle is a crucial component, integrating functions such as filling, supplying, manual venting, and safe release. To ensure reliable safety, the cylinder valve must rapidly activate for safe release when the external temperature exceeds a certain level, quickly expelling the high-pressure hydrogen from the cylinder.

[0003] Currently, existing safety relief methods, such as those disclosed in Chinese Utility Model Patent No. CN223019541U and Chinese Invention Patent Application No. CN117295909A, involve a relief valve core that is movably installed within a relief valve housing along a relief channel. The valve core is sealed by a sealing ring mounted on its outer circumference, which in turn seals against the inner circumference of the relief channel. A fusible alloy block is filled on the side of the valve core facing away from the relief channel within the relief valve housing. This block obstructs the valve core, placing it in a position that blocks the relief channel. When the external ambient temperature rises to a set value, the fusible alloy block melts, and the valve core, under the pressure of the gas inside the bottle and the force of a spring, moves away from the relief channel, thereby opening the channel and allowing relief. In this type of venting device, under normal conditions, the fusible alloy is subjected to significant stress due to the combined effects of the internal gas pressure (national standards require hydrogen cylinders to have an internal pressure as high as 70 MPa) and the spring. This makes it prone to creep failure, resulting in a failure to reliably stop the venting valve core. If the diameter of the venting channel is reduced or the gas pressure applied to the venting valve core is lowered to reduce the stress, the venting speed will decrease during venting. Therefore, the existing technology described above cannot simultaneously guarantee a fast venting speed and high reliability. Utility Model Content

[0004] The purpose of this invention is to provide a safety relief device to solve the problem that existing relief devices cannot simultaneously achieve both relief speed and reliability under high pressure environments. Simultaneously, this invention also provides a bottle valve using the aforementioned safety relief device to solve the same problem.

[0005] This utility model's safety relief device includes a relief valve housing and a relief valve core that is slidably installed in the relief valve housing along an axis. The relief valve core has a sealing section extending out of the relief valve housing and used for sealing insertion into a relief channel along the axis. A relief spring is fitted over the relief valve core to provide it with an elastic force in the relief direction. A fusible alloy blocking element is also filled inside the relief valve housing on the side of the relief valve core opposite to the sealing section to overcome the elastic force of the relief spring and keep the relief valve core in a blocked state. The relief valve core has a rearward extension along the axis to the side of the fusible alloy blocking element away from the sealing section. The sealing section and the extension section are sealed together on the circumferential surface of the relief valve core. The relief valve core has a gas pressure balance channel that connects the two ends of the relief valve core axially from the sealing section through the extension section. The extension section has a rear gas pressure bearing surface with the same area as the front gas pressure bearing surface of the sealing section to balance the gas pressure on the two ends of the relief valve core axially. The relief valve core is provided with a discharge hole for the fusible alloy blocking component to be discharged when it melts. When the set temperature for venting is reached, the fusible alloy blocking component melts, and the relief valve core moves in the venting direction under the thrust of the relief spring and squeezes the fusible alloy blocking component to be discharged, causing the sealing section to open the venting channel to achieve venting.

[0006] Furthermore, the vent valve housing is a nut structure, used for threaded installation on the bottle valve housing. The inner cavity of the nut is a stepped inner cavity. The vent valve core is in a sliding seal fit with the large diameter section, and the fusible alloy blocking component is installed in the large diameter section. The rear extension extends into the small diameter section and is in a sealing fit with the small diameter section. The discharge hole is located on the large diameter section.

[0007] Furthermore, the extension passes through the middle of the fusible alloy barrier, and there are multiple discharge holes that are evenly spaced in the circumferential direction.

[0008] Furthermore, a flow-blocking gasket is installed on the side of the fusible alloy barrier that faces away from the sealing section within the large-diameter section. The flow-blocking gasket is fully fitted to the end face of the fusible alloy barrier and allows the subsequent extension section to pass through.

[0009] Furthermore, the inner cavity of the cap is a two-stage stepped inner cavity including a middle diameter section between the large diameter section and the small diameter section. The middle diameter section is provided with a compression pad ring that is axially pressed against the stepped surface of the middle diameter section by the elastic force of the release spring, and the rear extension passes through the compression pad ring.

[0010] Furthermore, the sealing structure at the sealing section for sealing cooperation with the venting channel and the sealing structure at the extension section for sealing cooperation with the venting valve body have the same structure and end face dimensions.

[0011] This utility model's safety relief device improves upon existing technology by providing a rear extension section on the relief valve core and opening a gas pressure balance channel connecting the two axial ends of the relief valve core through the sealing section and the rear extension section. Furthermore, the design ensures that the rear extension section has a rear gas pressure-bearing surface area equal to the front gas pressure-bearing surface area of ​​the sealing section. This balances the gas pressure on both axial ends of the relief valve core, meaning the relief valve core is not subjected to pressure from the high-pressure gas inside the cylinder. The fusible alloy blocking component is always only subjected to the pressure of the relief spring and is balanced and supported by the relief spring on both sides of the relief valve core. This avoids the problem of poor reliability caused by the fusible alloy creep failure under pressure when the existing relief device is used with high-pressure gas cylinders.

[0012] The cylinder valve of this utility model includes a cylinder valve body, which has a venting channel communicating with the inner cavity of the gas cylinder. A safety venting device is installed at the outer end of the venting channel. The safety venting device includes a venting valve shell and a venting valve core that is slidably installed in the venting valve shell along an axis. The venting valve core has a sealing section extending out of the venting valve shell and used for sealing insertion into the venting channel along the axis. A venting spring is fitted over the venting valve core to provide it with an elastic force in the venting direction. A fusible alloy blocking element is also filled inside the venting valve shell on the side of the venting valve core facing away from the sealing section to overcome the elastic force of the venting spring and keep the venting valve core in a sealed state. The venting valve core has a sealing section extending out of the venting valve shell and used for sealing insertion into the venting channel along the axis. The axis extends to a rear extension of the fusible alloy blocking member on the side away from the sealing section. The rear extension is circumferentially sealed with the relief valve housing. The relief valve core has a gas pressure balance channel that connects the sealing section through the rear extension to both ends of the relief valve core axially. The rear extension has a rear gas pressure bearing surface with an area equal to the front gas pressure bearing surface of the sealing section to balance the gas pressure on both ends of the relief valve core axially. The relief valve housing is provided with a discharge hole for the fusible alloy blocking member to be discharged when it melts. When the set temperature for venting is reached, the fusible alloy blocking member melts, and the relief valve core moves in the venting direction under the thrust of the venting spring, squeezing the fusible alloy blocking member out and causing the sealing section to open the venting channel to achieve venting.

[0013] Furthermore, the vent valve housing is a nut structure, used for threaded installation on the bottle valve housing. The inner cavity of the nut is a stepped inner cavity. The vent valve core is in a sliding seal fit with the large diameter section, and the fusible alloy blocking component is installed in the large diameter section. The rear extension extends into the small diameter section and is in a sealing fit with the small diameter section. The discharge hole is located on the large diameter section.

[0014] Furthermore, the extension passes through the middle of the fusible alloy barrier, and there are multiple discharge holes that are evenly spaced in the circumferential direction.

[0015] Furthermore, a flow-blocking gasket is installed on the side of the fusible alloy barrier that faces away from the sealing section within the large-diameter section. The flow-blocking gasket is fully fitted to the end face of the fusible alloy barrier and allows the subsequent extension section to pass through.

[0016] Furthermore, the inner cavity of the cap is a two-stage stepped inner cavity including a middle diameter section between the large diameter section and the small diameter section. The middle diameter section is provided with a compression pad ring that is axially pressed against the stepped surface of the middle diameter section by the elastic force of the release spring, and the rear extension passes through the compression pad ring.

[0017] Furthermore, the sealing structure at the sealing section for sealing cooperation with the venting channel and the sealing structure at the extension section for sealing cooperation with the venting valve body have the same structure and end face dimensions.

[0018] Furthermore, on the cavity wall of the mounting chamber of the bottle valve body and the installation chamber of the vent valve housing, an external discharge channel is provided at the position corresponding to the discharge hole, and the diameter of the external discharge channel is larger than the diameter of the discharge hole.

[0019] Furthermore, the external drainage channel on the cavity wall of the mounting cavity corresponds to multiple discharge holes.

[0020] Furthermore, the bottle valve body includes a plate-shaped valve body, and the safety relief device is screwed into the plate-shaped valve body from the side. The plate-shaped valve body has a through channel in the thickness direction at the position corresponding to the discharge hole of the relief valve shell. The through channel is oblong and its length is greater than the outer diameter of the relief valve shell. The through channel constitutes an external discharge channel to connect all discharge holes on the relief valve shell.

[0021] This invention improves upon existing technology in its bottle valve design, particularly optimizing the safety relief device. By adding a rear extension section to the relief valve core and establishing a pressure balance channel connecting the two axial ends of the relief valve core via the sealing section and the rear extension section, and by designing the rear extension section to have a rear gas pressure-bearing surface area equal to the front gas pressure-bearing surface area of ​​the sealing section, the gas pressure on both axial ends of the relief valve core can be balanced. This means the relief valve core is not subjected to the pressure of the high-pressure gas inside the bottle, and the fusible alloy blocking component is always only subjected to the pressure of the relief spring and is balanced and supported by the relief spring on both sides of the relief valve core. This avoids the problem of poor reliability caused by the fusible alloy creep failure under pressure when the existing relief device is used with high-pressure gas cylinders. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view showing the safety relief device in a closed state in one embodiment of the bottle valve of this utility model; Figure 2 for Figure 1 Cross-sectional view at point AA; Figure 3 for Figure 1 The structure shown is a cross-sectional view in the venting state; Figure 4 for Figure 1 Side view of the portion shown.

[0023] In the diagram: 1. Bottle valve body; 10. Relief channel; 11. Mounting cavity; 12. Exhaust port; 2. Relief valve shell; 21. Small diameter section of inner cavity; 22. Medium diameter section of inner cavity; 23. Large diameter section of inner cavity; 24. Discharge hole; 3. Relief valve core; 31. Valve core mounting section; 32. Sealing section; 33. Extension section; 34. Pressure balance channel; 4. Sealing ring; 41. Protective ring; 5. Relief spring; 6. Fusible alloy blocking component; 7. Flow-blocking gasket; 8. Compression gasket ring; 9. External discharge channel. Detailed Implementation

[0024] This invention optimizes and improves existing safety relief devices in cylinder valves, particularly by modifying the structure of the relief valve core. By connecting the gas from the high-pressure cylinder to both axial ends of the relief valve core and ensuring equal gas pressure-bearing areas at both ends, the gas pressure on both axial ends of the relief valve core is balanced. This means the relief valve core is not subjected to the axial force of the high-pressure gas in the high-pressure cylinder. Consequently, the fusible alloy blocking component positioned in the relief direction is not subjected to the axial pressure exerted on the relief valve core by the high-pressure gas in the high-pressure cylinder, but only to the elastic force of the relief spring. This reduces and controls the pressure on the fusible alloy blocking component within a certain range, preventing creep failure due to excessive force and thus avoiding unexpected operation of the relief valve core when it is not intended to move in the relief direction. This improves the reliability of the safety relief device.

[0025] Specifically, the present invention will be described below with reference to the specific embodiments of the bottle valve.

[0026] In one specific embodiment, the valve is a valve for the neck of a high-pressure hydrogen cylinder, such as the valve disclosed in the applicant's previously filed invention patent with authorization publication number CN114777017B. Of course, in other specific embodiments, the valve can also be a valve used for the neck of a gas cylinder filled with other gases, such as nitrogen cylinders or oxygen cylinders.

[0027] The cylinder valve body 1 includes a cylindrical portion and a plate-shaped valve body located at one end of the cylindrical portion and perpendicular to the main body. The cylindrical portion is used to seal the mouth of the cylinder, and the plate-shaped valve body is used to integrate other necessary functional components, among which the safety release device is one. The cylindrical portion has an internal channel communicating with the inner cavity of the cylinder. The plate-shaped valve body has a release channel 10 perpendicularly communicating with the internal channel. On the side of the plate-shaped valve body, corresponding to the release channel 10, a mounting cavity 11 is coaxially formed for installing the safety release device. Under normal operating conditions, the release valve core 3 of the safety release device installed in the mounting cavity 11 can block the release channel 10 to prevent gas leakage from the cylinder. When the external environment reaches a certain dangerous condition, to ensure safety, the release valve core 3 of the safety release device needs to move quickly in the release direction to release the blockage of the release channel 10 and allow the gas in the cylinder to be quickly discharged to the outside.

[0028] The bottle valve disclosed in the applicant's previous invention patent application, with authorization publication number CN114777017B, or the appendix to the specification of this application, are relevant. Figure 2 , 3 It can be seen that an exhaust port 12 is provided on the side of the mounting cavity 11 on the plate-shaped valve body. The exhaust port 12 is connected to the inner end of the mounting cavity 11. When the relief valve core 3 moves in the relief direction and retracts into the mounting cavity 11 (e.g. Figure 3 As shown), the seal on the venting channel 10 is released, and the venting channel 10 is now connected to the inner cavity of the mounting cavity 11 and the exhaust port 12, allowing the gas in the high-pressure cylinder to be quickly discharged; when the venting valve core 3 blocks the venting channel 10 (as shown), the venting channel 10 is sealed. Figure 2 As shown in the figure, it blocks the connection between the venting channel 10 and the inner end cavity of the mounting cavity 11, ensuring that the gas in the high-pressure gas cylinder will not leak from here.

[0029] The structure of the safety relief device and its assembly on the plate-shaped valve body are detailed below: like Figure 1-4 As shown, the safety relief device includes a relief valve housing 2 and a relief valve core 3. The relief valve housing 2 is a nut structure, and its nut body includes an installation cylindrical section with external threads on its outer circumference and a screwing end at the end of the installation cylindrical section. The outer diameter of the screwing end is larger than that of the installation cylindrical section, and it is a structure with an external hexagonal or external square shape for easy screwing. The installation cavity 11 on the plate-shaped valve body is a stepped inner cavity, consisting of a large-diameter section and a small-diameter section from the outside to the inside. The large-diameter section has internal threads for the installation cylindrical section of the relief valve housing 2 to be screwed into. The stepped surface between the large-diameter section and the small-diameter section stops and positions the end of the installation cylindrical section to determine the screwing depth. A sealing ring groove is provided at the end of the large-diameter section, and a sealing ring 4 is installed in the sealing ring groove. When the relief valve housing 2 is tightened in the installation cavity 11, the inner end face of the screwing end presses against the sealing ring 4 to ensure the seal between the relief valve housing 2 and the plate-shaped valve body.

[0030] A relief valve core 3 is installed in the inner cavity of the cap of the relief valve housing 2. The relief valve core 3 is slidably and sealingly installed in the inner cavity of the cap along its axis. The cross-sectional shape of the relief valve housing 2, the inner cavity of the cap, and the relief valve core 3 perpendicular to the axis is circular. The axis of the relief valve core 3 is coaxial with the relief channel 10. The section of the relief valve core 3 facing the relief channel 10 is a sealing section 32, which is used to insert into the relief channel 10 and seal with the inner circumferential surface of the relief channel 10 through the sealing structure on its outer circumferential surface. The part of the relief valve core 3 from the sealing section 32 to the part that seals with the installation cylinder section is a three-step cylindrical structure with the outer diameter gradually increasing. The outer circumferential surface of the section with the smallest inner diameter is equipped with a sealing structure for sealing with the relief channel 10, forming the sealing section 32. The outer circumferential surface of the section with the largest inner diameter of the installation cylinder section is equipped with a sealing structure (in the embodiment shown in the figure, a sealing ring 4 installed in the sealing ring groove set on the outer circumferential surface), which is used to slide and seal with the installation cylinder section, forming the valve core installation section 31.

[0031] A relief spring 5 is also fitted on the outside of the relief valve core 3. The relief spring 5 is a compression spring. One end of the spring supports the end face of the largest diameter section of the relief valve core 3 in the installation cylinder section, and the other end supports the bottom of the installation cavity 11, thereby providing the relief valve core 3 with an outward (i.e. relief direction) elastic force. A fusible alloy blocking member 6 is filled in the installation cavity 11 on the side of the relief valve core 3 away from the sealing section 32, and the fusible alloy blocking member 6 blocks the relief valve core 3.

[0032] Since the sealing section 32 and its outer sealing structure extend into the venting channel 10, the inner end of the sealing section 32 forms a front pressure bearing surface to withstand the pressure of the high-pressure gas in the high-pressure cylinder. In order to ensure that the fusible alloy blocking member 6 only bears the elastic force of the venting spring 5 and achieves force balance with the venting spring 5 on both sides of the venting valve core 3, the venting valve core 3 has a rear extension section 33 extending rearward from the rear side (i.e., the outward side) of the section with the largest diameter in the installation cylinder section. The rear extension section 33 extends to the rear side of the fusible alloy blocking member 6 and seals with the inner cavity of the cap on the circumferential surface. Moreover, the venting valve core 3 has a section extending from the sealing section 32. The front end of the gas valve core 3 extends to the rear end of the rear extension 33 via a pressure balance channel 34, allowing the high-pressure gas in the relief channel 10 connected to the inner cavity of the high-pressure gas cylinder to flow to the rear side of the rear extension 33 via the pressure balance channel 34. The outer end of the rear extension 33 forms a rear pressure bearing surface to bear the pressure of the high-pressure gas, making the area of ​​the rear pressure bearing surface equal to that of the front pressure bearing surface. This ensures that the gas pressure on the front pressure bearing surface and the rear pressure bearing surface is equal, thereby preventing the fusible alloy blocking element 6 from bearing outward gas pressure or the relief spring 5 from bearing inward gas pressure due to the unequal gas pressure on both ends of the axial direction.

[0033] To achieve the above objective, namely, to ensure that the gas pressure on the front and rear pressure-bearing surfaces is equal, this embodiment makes the outer diameter of the sealing section 32 equal to the outer diameter of the rear extension section 33, and the inner diameter of the pressure balancing channel 34 at the sealing section 32 and the rear extension section 33 equal (in the embodiment shown in the figure, the pressure balancing channel 34 is an axially penetrating straight hole with a constant inner diameter). Furthermore, the sealing structure between the sealing section 32 and the venting channel 10, and the sealing structure between the rear extension section 33 and the inner cavity of the cap, have the same structural form and end face dimensions. That is, the inner cavity of the cap includes a small-diameter section 21 that seals against the rear extension section 33. Combined with... Figure 2-3 It can be seen that the sealing structures at both locations include a sealing ring 4 and protective rings 41 located on both axial sides of the sealing ring 4. The protective rings 41 are made of PEEK material to prevent the axial side of the rubber sealing ring 4 from being directly squeezed by the metal relief valve core 3. Of course, in other embodiments, the above objectives can also be achieved by matching the outer diameters of the extension section 33 and the sealing section 32, the inner diameter of the air pressure balance channel 34, and the structural form and size of the sealing structure. These are all variations that can be implemented by those skilled in the art based on their own capabilities and knowledge.

[0034] When the gas pressure balance of the relief valve core 3 in the axial direction is achieved by using the method described above, the inner diameter of the cavity part that mates with the rear extension 33 in the cap body cavity is equal to the inner diameter of the relief channel 10. That is, the cap body cavity is a stepped inner cavity that includes the inner large diameter section (the inner cavity that is in a sealing and sliding fit with the largest diameter of the relief valve core 3) and the outer small diameter section (the inner cavity that is in a sealing fit with the rear extension 33 of the relief valve core 3).

[0035] The relief valve housing 2 has a discharge hole 24 on the wall of the mounting section. The axial position of the discharge hole 24 corresponds to the fusible alloy blocking element 6. The plate-shaped valve body has an external discharge channel 9 that connects the discharge hole 24 to the outside of the plate-shaped valve body. When the external ambient temperature reaches the set temperature (not less than the melting point of the fusible alloy blocking element 6), the fusible alloy blocking element 6 melts rapidly. The relief valve core 3 moves in the discharge direction under the elastic force of the relief spring 5. The valve core mounting section 31 of the relief valve core 3 acts as a piston, squeezing the molten fusible alloy out of the discharge hole 24 into the inner cavity of the cap body. The molten fusible alloy is then discharged from the plate-shaped valve body through the external discharge channel 9, thereby realizing the movement of the relief valve core 3 in the discharge direction and opening the relief channel 10. To achieve this process, the distance between the piston's pressing surface, i.e., the axial contact surface between the valve core mounting section 31 and the fusible alloy blocking member 6, and the discharge hole 24 must satisfy the following: at least when the pressing surface just moves to the edge position of the discharge hole 24 on the side opposite to the discharge channel 10, the sealing section 32 exits from the discharge channel 10, and the discharge channel 10 is released from sealing.

[0036] The above-described embodiments can realize the basic functions of the safety relief device and achieve the main design purpose and solve the technical problems of this utility model. In a more optimized embodiment, in order to prevent the molten fusible alloy blocking member 6 from being squeezed outward by the relief valve core 3 and exerting an axial force on the sealing structure on the rear extension 33, a flow-blocking pad 7 is provided on the outside of the fusible alloy blocking member 6 in the large-diameter section of the cap's inner cavity, i.e., the large-diameter section 23 of the inner cavity. The outer diameter of the flow-blocking pad 7 is consistent with the inner diameter of the large-diameter section of the inner cavity and the outer diameter of the fusible alloy blocking member 6. The flow-blocking pad 7 is provided with a clearance hole that matches the outer diameter of the rear extension 33. The rear extension 33 passes through the clearance hole and the flow-blocking pad 7 can prevent the molten fusible alloy from flowing to the rear extension 33 side.

[0037] Based on the implementation method described above, in another preferred embodiment, the inner cavity of the cap is a two-stage stepped inner cavity comprising an inner cavity middle diameter section 22 located between the large diameter section 23 and the small diameter section 21. The middle diameter section is provided with a compression washer 8, which is axially pressed against the stepped surface of the middle diameter section by the elastic force of the relief spring 5. The compression washer 8 has a clearance hole adapted to the outer diameter of the rear extension section 33, through which the rear extension section 33 passes. The compression washer 8 provides a double barrier between the molten fusible alloy and the sealing structure of the rear extension section 33, and also, in conjunction with the flow-blocking gasket 7, allows the outer end of the thinner rear extension section 33 to be straightened twice, ensuring consistent sealing between the rear extension section 33 and the inner cavity of the cap in the circumferential direction.

[0038] In the embodiments described above, such as Figure 1-3 As shown, the extension section 33 is coaxial with the sealing section 32 and passes through the center of the fusible alloy blocking member 6. Thus, when the fusible alloy blocking member 6 melts and is squeezed by the relief valve core 3, in order to facilitate the rapid discharge of the molten fusible alloy from the relief valve shell 2, in a preferred embodiment, multiple discharge holes 24 are uniformly provided in the circumferential direction of the mounting cylinder section, so that the fusible alloy can be discharged outwards at multiple positions in the circumferential direction at the same time.

[0039] In a preferred embodiment, the outward discharge channels 9 on the plate-shaped valve body correspond one-to-one with the discharge holes 24 on the relief valve shell 2, and the diameter of the outward discharge channel 9 is larger than the diameter of the discharge hole 24, thus preventing material blockage during the discharge of molten fusible alloy from the bottle valve. Alternatively, in other embodiments, the number of outward discharge channels 9 is less than the number of discharge holes 24, and some outward discharge channels 9 correspond to multiple discharge holes 24, and the flow rate of the outward discharge channel 9 is greater than the sum of the flow rates of the multiple discharge holes 24. Figure 3-4In the embodiment shown, the plate-shaped valve body has a through channel in the thickness direction at the position corresponding to the discharge hole 24 of the relief valve shell 2. The through channel is oblong and its length is greater than the outer diameter of the relief valve shell 2. The through channel constitutes an external discharge channel 9 to connect all the discharge holes 24 on the relief valve shell 2. This method reduces the processing difficulty of the external discharge channel 9 and allows observation of the discharge situation at the discharge hole 24.

[0040] As can be seen from the above description of the bottle valve of this utility model in combination with different embodiments, the discharge valve core 3 of the safety discharge device in the bottle valve of this utility model is not subject to the axial pressure of high-pressure gas, so that the fusible alloy blocking member 6 only needs to bear the elastic force of the discharge spring 5 in the axial direction, which eliminates the problem of creep failure of the fusible alloy blocking member 6 under the pressure of high-pressure gas in the prior art when applied in a high-pressure environment; moreover, after the gas pressure at both ends of the discharge valve core 3 is balanced, no axial pressure will be applied to the discharge valve core 3 regardless of whether the diameter of the discharge channel 10 is large or small. In this way, the diameter of the discharge channel 10 can be increased compared with the prior art, which facilitates rapid discharge and improves safety.

[0041] The specific structure of the safety relief device of this utility model is the same as that of the safety relief device in the bottle valve embodiment described above, and will not be repeated here.

[0042] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A safety relief device, comprising a relief valve housing and a relief valve core slidably mounted in the relief valve housing along an axis, the relief valve core having a sealing section extending out of the relief valve housing and used for sealing insertion into a relief channel along said axis, a relief spring being sleeved on the relief valve core to provide it with an elastic force in the relief direction, and a fusible alloy blocking element being filled in the relief valve housing on the side of the relief valve core opposite to the sealing section to overcome the elastic force of the relief spring and keep the relief valve core in a blocked state, characterized in that... The relief valve core has a rear extension extending along the axis to the side of the fusible alloy blocking member away from the sealing section. The rear extension is circumferentially sealed with the relief valve housing. The relief valve core has a gas pressure balance channel connecting the sealing section and the two ends of the relief valve core axially. The rear extension has a rear gas pressure bearing surface with an area equal to the front gas pressure bearing surface of the sealing section to balance the gas pressure on the two ends of the relief valve core axially. The relief valve housing is provided with a discharge hole for the fusible alloy blocking member to be discharged when it melts. When the set temperature for venting is reached, the fusible alloy blocking member melts, and the relief valve core moves in the venting direction under the thrust of the relief spring, squeezing the fusible alloy blocking member out and causing the sealing section to open the venting channel to achieve venting.

2. The safety relief device according to claim 1, characterized in that, The relief valve housing is a nut structure, used for threaded installation on the bottle valve housing. The inner cavity of the nut is a stepped inner cavity. The relief valve core is sealed and slidably fitted with the large diameter section, and the fusible alloy blocking part is installed in the large diameter section. The rear extension extends into the small diameter section and is sealed and fitted with the small diameter section. The discharge hole is located on the large diameter section.

3. The safety relief device according to claim 2, characterized in that, The extension section passes through the middle of the fusible alloy barrier, and there are multiple discharge holes that are evenly spaced in the circumferential direction.

4. The safety relief device according to claim 2, characterized in that, The large-diameter section has a flow-blocking gasket installed on the side of the fusible alloy blocking component facing away from the sealing section. The flow-blocking gasket is fully fitted with the end face of the fusible alloy blocking component and allows the subsequent extension section to pass through.

5. The safety relief device according to claim 4, characterized in that, The inner cavity of the cap consists of a two-stage stepped inner cavity, including a middle diameter section between the large diameter section and the small diameter section. The middle diameter section is equipped with a compression pad ring that is axially pressed against the stepped surface of the middle diameter section by the elastic force of the release spring, and the rear extension passes through the compression pad ring.

6. The safety relief device according to any one of claims 1-5, characterized in that, The sealing structure at the sealing section, which is used to seal and cooperate with the venting channel, and the sealing structure at the extension section, which is used to seal and cooperate with the venting valve body, have the same structure and end face dimensions.

7. A cylinder valve, comprising a valve body, wherein the valve body has a venting channel communicating with the inner cavity of a gas cylinder, and a safety venting device is installed at the outer end of the venting channel, characterized in that, The safety relief device is the safety relief device according to any one of claims 1-6.

8. The bottle valve according to claim 7, characterized in that, On the cavity wall of the installation chamber of the bottle valve body, corresponding to the position of the discharge hole, there is an external discharge channel, the diameter of which is larger than the diameter of the discharge hole.

9. The bottle valve according to claim 8, characterized in that, The external drainage channel on the cavity wall of the mounting cavity corresponds to multiple discharge holes.

10. The bottle valve according to claim 9, characterized in that, The bottle valve body includes a plate-shaped valve body. The safety relief device is screwed into the plate-shaped valve body from the side. The plate-shaped valve body has a through channel in the thickness direction at the position corresponding to the discharge hole of the relief valve shell. The through channel is oblong and its length is greater than the outer diameter of the relief valve shell. The through channel constitutes an external discharge channel to connect all discharge holes on the relief valve shell.

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