A two-stage pressure reduction valve for an air respirator

Abstract

This invention provides a two-stage pressure reducing valve for an air respirator. By sequentially arranging a primary pressure reducing chamber and a secondary pressure reducing chamber in the gas transmission channel of the valve body, and configuring a pressure reducing piston and spring in each chamber, precise partial pressure reduction of high-pressure gas is achieved. The primary pressure reducing chamber first performs initial pressure reduction and buffering on the gas from the external high-pressure gas source, effectively reducing the interference of initial pressure fluctuations on the subsequent pressure reduction process. The secondary pressure reducing chamber further stabilizes the pressure reduction, improving the stability of the final gas pressure output to the outlet. Simultaneously, compared to a single pressure reducing chamber, the two-stage pressure reducing chamber design reduces the likelihood of fatigue damage to core components such as the pressure reducing piston and spring due to prolonged exposure to excessive pressure. Furthermore, the two-stage pressure reducing structure provides dual safety protection; even if the primary pressure reducing chamber malfunctions and fails to effectively reduce pressure, the secondary pressure reducing chamber can still perform secondary pressure reduction control of the gas, preventing direct output of high-pressure gas.

Description

Technical Field

[0001] This utility model relates to the field of pressure reducing valve technology, and in particular to a two-stage pressure reducing valve for use in air respirators. Background Technology

[0002] In the application of self-contained breathing apparatus (SCBA), the decompression of high-pressure gas is crucial to ensure safe and comfortable breathing for users. Currently, single-stage pressure reducers are widely used in the SCBA market. However, as the performance requirements for SCBA continue to increase, some shortcomings of single-stage pressure reducers have gradually become apparent.

[0003] A single-stage pressure reducer typically reduces the pressure of high-pressure gas using only a single pressure-reducing chamber. In actual use, due to factors such as fluctuations in the gas source pressure and changes in the operating environment, this single-chamber design makes it difficult to guarantee the stability of the pressure reduction process. For example, when the initial pressure of the high-pressure gas fluctuates significantly, the gas pressure output by the single-stage pressure reducer will also fluctuate. This may cause the user to experience noticeable pressure changes during breathing, affecting the user experience, and in extreme cases, potentially damaging the user's respiratory system.

[0004] In terms of service life, the primary pressure regulator is constantly subjected to the impact of high-pressure gas, and its internal pressure-reducing components endure significant pressure and wear. Especially under frequent use or harsh environments, these components are prone to fatigue and damage, thus shortening the overall service life of the pressure regulator. Once the pressure regulator malfunctions, it will not only affect the normal use of the air respirator but may also pose a safety hazard to the user.

[0005] In terms of safety, single-stage pressure reducers lack sufficient pressure reduction stability and may fail to adjust and control in a timely and effective manner when the output pressure exceeds the safe range. Moreover, a single pressure reducing chamber lacks adequate buffering and protection mechanisms when facing sudden high-pressure gas impacts, which can easily lead to safety accidents such as gas leaks, posing a threat to the user's life.

[0006] In summary, existing single-stage pressure regulators have significant shortcomings in terms of pressure reduction stability, service life, and safety, failing to meet the growing demand for high-performance and high-reliability air respirators. Therefore, developing a new type of pressure regulator that can solve these problems is of significant practical importance. Utility Model Content

[0007] The purpose of this invention is to provide a two-stage pressure reducing valve for an air respirator, which achieves precise pressure reduction by setting a primary pressure reducing chamber and a secondary pressure reducing chamber connected in sequence inside the valve body.

[0008] This utility model provides a two-stage pressure reducing valve for an air respirator, comprising a valve body, the valve body including an air inlet and an air outlet, the air inlet being connected to an external high-pressure air source, and a gas transmission channel connecting the air inlet and the air outlet, wherein a primary pressure reducing chamber and a secondary pressure reducing chamber are sequentially arranged on the gas transmission channel; the primary pressure reducing chamber is provided with a first pressure reducing piston and a first spring, and a first pressure plate is installed at the port of the primary pressure reducing chamber, the first spring abutting between the first pressure reducing piston and the first pressure plate; the secondary pressure reducing chamber is provided with a second pressure reducing piston and a second spring, and a second pressure plate is installed at the port of the secondary pressure reducing chamber, the second spring abutting between the second pressure reducing piston and the second pressure plate.

[0009] Furthermore, a connection assembly for communicating with a high-pressure gas cylinder is installed at the air inlet of the valve body. The connection assembly includes a connecting rod and a handwheel. The connecting rod has a through channel communicating with the air inlet along the axial direction. The connecting rod is fixedly installed at the air inlet of the valve body by threads. The handwheel is rotatably installed on the connecting rod and has an external thread for connecting with the high-pressure gas cylinder.

[0010] Furthermore, a filter is installed at the air inlet end of the connecting rod.

[0011] Furthermore, a sealing ring is provided on the end face of the air inlet end of the connecting rod.

[0012] Furthermore, the valve body is connected to a high-pressure interface, an alarm interface, and a medium-pressure interface. The high-pressure interface and the alarm interface are both connected to the air inlet section of the gas transmission channel, and the medium-pressure interface is connected to the air outlet section of the gas transmission channel. A pressure gauge is connected to the high-pressure interface, an alarm whistle is installed on the alarm interface, the medium-pressure interface is connected to the air outlet of the valve body, and the outside of the medium-pressure interface is connected to the respirator.

[0013] Furthermore, the second pressure plate includes a pressure plate body, and an adjustable adjusting screw is threadedly installed at the center of the pressure plate body.

[0014] Furthermore, the inner wall of the gas transmission channel is a smooth surface.

[0015] Furthermore, the first decompression piston includes a first large piston and a first small piston. The first large piston has a first decompression channel inside for connecting the air inlet and the first-stage decompression chamber. The first small piston is slidably sleeved inside the first large piston. The first spring abuts against the first pressure plate and the first large piston respectively. The inner side of the first pressure plate is provided with a limiting cone.

[0016] Furthermore, the second decompression piston includes a second large piston and a second small piston. The second large piston has a second decompression channel inside for connecting the first-stage decompression chamber and the second-stage decompression chamber. The second small piston is slidably sleeved inside the second large piston. The second spring abuts against the second pressure plate and the second large piston respectively.

[0017] Furthermore, a safety valve is provided inside the medium-pressure interface. The safety valve includes a valve body, a piston ring, and a safety valve spring. The piston ring and the safety valve spring are both sleeved on the valve body. The two ends of the safety valve spring abut against the piston ring and the valve body, respectively. A pressure relief port is provided on the valve body at the port position of the medium-pressure interface.

[0018] The technical solution of this utility model achieves precise distributed pressure reduction of high-pressure gas by sequentially arranging a primary pressure-reducing chamber and a secondary pressure-reducing chamber in the gas transmission channel of the valve body, and respectively configuring a first pressure-reducing piston, a first spring, a first pressure plate, a second pressure-reducing piston, a second spring, and a second pressure plate in each chamber. The primary pressure-reducing chamber first performs preliminary pressure reduction and buffering on the gas from the external high-pressure gas source, which can effectively reduce the interference of initial pressure fluctuations on the subsequent pressure reduction process. The secondary pressure-reducing chamber further stabilizes the pressure reduction on this basis, which greatly improves the stability of the gas pressure finally output to the outlet and avoids the user's breathing due to pressure fluctuations. Poor breathing experience or damage to the respiratory system; at the same time, the two-stage pressure reducing chambers share the impact load of high-pressure gas and the wear of internal components. Compared with a single pressure reducing chamber, it reduces the fatigue damage of core components such as pressure reducing pistons and springs due to long-term excessive pressure, significantly extending the overall service life of the pressure reducing valve; in addition, the two-stage pressure reducing structure forms double safety protection. Even if the first-stage pressure reducing chamber fails to effectively reduce pressure, the second-stage pressure reducing chamber can still perform secondary pressure reducing control of the gas, avoiding direct output of high-pressure gas, reducing the risk of safety accidents such as gas leakage, and ensuring the safety of users. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a top view of a two-stage pressure reducing valve.

[0021] Figure 2 For the two-stage pressure reducing valve Figure 1 A sectional view of DD.

[0022] Figure 3 This is a side view of a two-stage pressure reducing valve.

[0023] Figure 4 For the two-stage pressure reducing valve Figure 3 A sectional view of CC.

[0024] Explanation of reference numerals in the attached diagram: 1-Valve body, 2-First-stage pressure reducing chamber, 3-First pressure reducing piston, 301-First large piston, 302-First small piston, 303-Connecting hole, 4-First spring, 5-First pressure plate, 501-Limit cone, 6-Connecting rod, 7-Handwheel, 8-Filter, 9-Nut, 10-Sealing ring, 11-High-pressure interface, 12-Alarm whistle, 13-Medium-pressure interface, 14-Second-stage pressure reducing chamber, 15-Second pressure reducing piston, 1501-Second large piston, 1502-Second small piston, 16-Second spring, 17-Pressure plate body, 18-Adjusting screw, 19-Flow regulating screw, 20-High-pressure outer pipe, 21-Alarm piston, 22-Middle hole nut, 23-Middle hole piston, 24-Spring base, 25-Middle hole spring, 26-Safety valve spring, 27-Medium-pressure pipe, 28-Piston ring, 29-Valve body, 2901-Pressure relief port. Detailed Implementation

[0025] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Example 1 like Figures 1-4 As shown, this utility model provides a two-stage pressure reducing valve for an air respirator, including a valve body 1. The valve body 1 includes an air inlet and an air outlet. The valve body 1 is supported by a high-strength, high-pressure resistant, and corrosion-resistant 6061 aluminum alloy, which not only provides a stable support environment for internal components but also resists damage to the pressure reducer from the external environment. The air inlet is connected to an external high-pressure gas source (high-pressure gas cylinder) and is responsible for introducing high-pressure gas into the pressure reducer. A gas transmission channel is connected between the air inlet and the air outlet. The gas transmission channel is provided with a primary pressure reducing chamber 2 and a secondary pressure reducing chamber 14 in sequence. The inner wall of the gas transmission channel is a smooth wall surface, that is, the inner surface of the channel is smoothed to reduce the resistance and pressure loss of the gas during transmission.

[0029] A connection assembly for communicating with a high-pressure gas cylinder is installed at the air inlet of the valve body 1. The connection assembly includes a connecting rod 6 and a handwheel 7. The connecting rod 6 has a through channel communicating with the air inlet along the axial direction. The connecting rod 6 is fixedly installed at the air inlet of the valve body 1 by threads. The handwheel 7 is rotatably installed on the connecting rod 6. The handwheel 7 has an external thread for connecting with the high-pressure gas cylinder.

[0030] The primary decompression chamber 2 is located near the air inlet. Inside the primary decompression chamber 2 are a first decompression piston 3 and a first spring 4. A first pressure plate 5 is installed at the port of the primary decompression chamber 2. The first decompression piston 3 includes a first large piston 301 and a first small piston 302. The first large piston 301 has a first decompression channel inside for connecting the air inlet and the primary decompression chamber 2. The first small piston 302 is slidably fitted inside the first large piston 301. The first spring 4 abuts against both the first pressure plate 5 and the first large piston 301. A limiting cone is provided on the inner side of the first pressure plate 5. 501 is used to limit the extreme displacement of the first small piston 302. When the high-pressure gas pushes the first depressurization piston 3 to move, there is a spring behind the first large piston 301, but no spring behind the first small piston 302. Therefore, the first small piston 302 moves to the right faster than the first large piston 301, thus exposing the connecting hole 303. Afterwards, when the first large piston 301 continues to move towards the first pressure plate side, the first small piston 302 cannot continue to move because it is against the limiting cone 501. Therefore, the relative displacement between the first large piston 301 and the first small piston 302 decreases until it disappears, and the connecting hole 303 is closed. During operation: High-pressure gas enters through the inlet, pushing the first pressure-reducing piston 3 to compress the first spring 4 to the right. Simultaneously, high-pressure gas flows in from the piston rod of the first large piston 301, pushing the first small piston 302 relative to the first large piston 301 to the pressure plate. At this point, the connecting hole 303 between the front end of the first small piston 302 and the piston rod of the first large piston 301 is exposed, allowing gas to flow into the primary pressure-reducing chamber 2 and then into the secondary pressure-reducing chamber 14. Then, as the first large piston 301 continues to move to the right, the connecting hole 303 is closed again, trapping the gas within the piston rod of the first large piston 301. As the gas pressure in the primary pressure-reducing chamber 2 decreases, the first large piston 301 is pushed back by the first spring 4, exposing the connecting hole 303 again, allowing gas to continue flowing into the primary pressure-reducing chamber 2. Consequently, the first large piston 301 moves towards the first pressure plate 5, and the process repeats. This structural design achieves initial pressure reduction by changing the gas flow area, reducing the high-pressure gas to approximately 2 MPa.

[0031] The secondary decompression chamber 14 is equipped with a second decompression piston 15 and a second spring 16. A second pressure plate is installed at the port of the secondary decompression chamber 14. The second decompression piston 15 includes a second large piston 1501 and a second small piston 1502. The second large piston 1501 has a second decompression channel inside for connecting the primary decompression chamber 2 and the secondary decompression chamber 14. The second small piston 1502 is slidably sleeved inside the second large piston 1501. The second spring 16 abuts against the second pressure plate and the second large piston 1501 respectively. The movement principle of the second large piston 1501 and the second small piston 1502 in the second decompression piston 15 is the same as that of the first large piston 301 and the first small piston 302. The second pressure plate includes a pressure plate body 17. An adjustable adjusting screw 18 is threaded at the center of the pressure plate body 17. The adjusting screw 18 abuts against the second small piston 1502. By tightening or loosening the adjusting screw 18, the pressure of the medium-pressure output can be adjusted. Specifically, by turning the adjusting screw 18, the displacement of the second small piston 1502 driven by the high-pressure gas can be changed, thereby altering the relative displacement between the second small piston 1502 and the second large piston 1501. This, in turn, changes the amount of gas that can enter the secondary pressure-reducing chamber 14 through the small hole of the second large piston 1501, thus changing the pressure value of the medium-pressure output. When the gas, after undergoing primary pressure reduction, enters the secondary pressure-reducing chamber 14 through the gas transmission channel, the gas pressure acts on the second pressure-reducing piston 15, further reducing the gas pressure from approximately 2 MPa to approximately 0.7 MPa. During this process, the gas flow area is precisely adjusted by controlling the displacement of the second small piston 1502, thereby achieving precise pressure reduction.

[0032] A filter 8 is installed at the air inlet end of the connecting rod 6. The filter 8 is installed on the connecting rod 6 through a nut 9. The filter 8 is used to filter the air source before pressure reduction. A sealing ring 10 is provided on the end face of the air inlet end of the connecting rod 6 to play a sealing role when connected to a high-pressure gas cylinder to prevent air leakage.

[0033] The valve body 1 is connected to a high-pressure port 11, an alarm port, and a medium-pressure port 13. Both the high-pressure port 11 and the alarm port are connected to the inlet section of the gas transmission channel. A pressure gauge is connected to the high-pressure port 11 to display the pressure of the high-pressure gas source. There is a flow adjustment screw 19 inside the high-pressure port 11. By tightening or loosening this screw, the flow rate of the high-pressure gas passing through this port can be adjusted. Then, the port is connected to the pressure gauge through a high-pressure outer tube 20 (the inner part of the outer tube is a spiral copper tube, and the outer part is rubber) to display the remaining gas pressure of the gas source in real time.

[0034] An alarm whistle 12 is installed on the alarm interface. When the gas source pressure drops to between 5 and 6 MPa, the alarm whistle 12 will emit a sound (≥90 decibels) to remind the user that the gas source pressure is insufficient. The alarm interface mainly includes a central hole piston 23, a central hole spring 25, a spring base 24, and an alarm piston 21. When the gas source pressure is greater than the alarm pressure (designed to be 5-6 MPa), the high-pressure gas pushes the alarm piston 21 upward, which in turn pushes the central hole piston 23 and the spring base 24 to overcome the elastic force of the central hole spring 25 and move upward until the alarm piston 21 is tightly pressed against the central hole nut 22. At this time, the gas flow passage in the middle of the central hole nut 22 is blocked, so no gas passes through the alarm whistle 12, and therefore there is no alarm sound. When the gas source pressure drops to the alarm pressure, the central hole spring 25 pushes the spring base 24 and the piston, which in turn pushes the alarm piston 21 away from the central hole nut 22. At this time, the central hole is exposed, and the gas flows into the central hole and then into the alarm whistle 12, emitting an alarm sound.

[0035] The medium-pressure interface 13 is internally connected to the outlet section of the gas transmission channel, and externally connected to the respirator. A safety valve is installed inside the medium-pressure interface. The safety valve includes a valve body 29, a piston ring 28, and a safety valve spring 26. The valve body has a pressure relief port. When the output medium pressure exceeds the design safety pressure, it pushes the piston ring 28 upwards, overcoming the pressure of the safety valve spring 26. At this time, gas flows out from the gap between the valve body and the medium-pressure interface into the pressure relief port 2901 on the valve body, releasing pressure and protecting personnel's breathing safety. The medium-pressure interface 13 is externally connected to a medium-pressure pipe 27. The other end of the medium-pressure pipe 27 is connected to a tee connector, which can be connected to a gas supply valve. Gas, after two stages of pressure reduction, is output from here for personnel breathing.

[0036] In actual operation, high-pressure gas enters the pressure reducer through the inlet, undergoes initial pressure reduction in the primary pressure reduction chamber 2, and then enters the secondary pressure reduction chamber 14 through the gas transmission channel for secondary pressure reduction and stabilization. Finally, gas with a stable pressure is output from the outlet for personnel breathing. Throughout the process, all components work together to achieve efficient and stable pressure reduction. Regarding pressure reduction stability, the primary pressure reduction chamber 2 initially reduces the high-pressure gas to approximately 2 MPa, providing a relatively stable input pressure for the secondary pressure reduction chamber 14. This allows the secondary pressure reduction chamber 14 to more precisely reduce the gas pressure to 0.7 MPa. This step-by-step pressure reduction method effectively reduces the impact of initial gas pressure fluctuations on the final output pressure. From a service life perspective, on the one hand, the two pressure reduction chambers share the gas pressure impact and wear; on the other hand, due to the improved pressure reduction stability, the pressure changes experienced by the internal components of the pressure reducer are more stable, avoiding fatigue damage caused by frequent and large pressure fluctuations. In terms of safety, the two-stage pressure reduction design adds an extra layer of safety. When the first-stage pressure reduction chamber 2 malfunctions and fails to effectively reduce the gas pressure to the predetermined range, the second-stage pressure reduction chamber 14 can still reduce the gas pressure again, preventing high-pressure gas from being directly output. Moreover, due to the improved stability of the output pressure, the risk of gas leakage caused by excessive pressure fluctuations is reduced.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A two-stage pressure reducing valve for an air respirator, characterized in that, The device includes a valve body, which has an air inlet and an air outlet. The air inlet is connected to an external high-pressure air source, and a gas transmission channel is connected between the air inlet and the air outlet. A primary pressure-reducing chamber and a secondary pressure-reducing chamber are sequentially arranged on the gas transmission channel. The primary pressure-reducing chamber is equipped with a first pressure-reducing piston and a first spring. A first pressure plate is installed at the port of the primary pressure-reducing chamber, and the first spring abuts between the first pressure-reducing piston and the first pressure plate. The secondary pressure-reducing chamber is equipped with a second pressure-reducing piston and a second spring. A second pressure plate is installed at the port of the secondary pressure-reducing chamber, and the second spring abuts between the second pressure-reducing piston and the second pressure plate.

2. The two-stage pressure reducing valve for an air respirator according to claim 1, characterized in that, The valve body is equipped with a connection component for communicating with a high-pressure gas cylinder at the air inlet. The connection component includes a connecting rod and a handwheel. The connecting rod has a through channel along the axial direction that communicates with the air inlet. The connecting rod is fixedly installed at the air inlet of the valve body by threads. The handwheel is rotatably installed on the connecting rod and has an external thread for connecting with the high-pressure gas cylinder.

3. The two-stage pressure reducing valve for an air respirator according to claim 2, characterized in that, A filter is installed at the air inlet end of the connecting rod.

4. The secondary pressure reducing valve for an air respirator according to claim 2, characterized in that, A sealing ring is provided on the end face of the air inlet end of the connecting rod.

5. The two-stage pressure reducing valve for an air respirator according to claim 1, characterized in that, The valve body is connected to a high-pressure interface, an alarm interface, and a medium-pressure interface. The high-pressure interface and the alarm interface are both connected to the air inlet section of the gas transmission channel, and the medium-pressure interface is connected to the air outlet section of the gas transmission channel. A pressure gauge is connected to the high-pressure interface, an alarm whistle is installed on the alarm interface, the medium-pressure interface is connected to the air outlet of the valve body, and the outside of the medium-pressure interface is connected to the respirator.

6. The two-stage pressure reducing valve for an air respirator according to claim 1, characterized in that, The second pressure plate includes a pressure plate body, and an adjustable adjusting screw is threadedly installed at the center of the pressure plate body.

7. The two-stage pressure reducing valve for an air respirator according to claim 1, characterized in that, The inner wall of the gas transmission channel is a smooth surface.

8. The two-stage pressure reducing valve for an air respirator according to claim 1, characterized in that, The first pressure-reducing piston includes a first large piston and a first small piston. The first large piston has a first pressure-reducing channel inside for connecting the air inlet and the first-stage pressure-reducing chamber. The first small piston is slidably sleeved inside the first large piston. The first spring abuts against the first pressure plate and the first large piston respectively. The inner side of the first pressure plate is provided with a limiting cone.

9. The two-stage pressure reducing valve for an air respirator according to claim 1, characterized in that, The second decompression piston includes a second large piston and a second small piston. The second large piston has a second decompression channel inside for connecting the first-stage decompression chamber and the second-stage decompression chamber. The second small piston is slidably sleeved inside the second large piston. The second spring abuts against the second pressure plate and the second large piston respectively.

10. The two-stage pressure reducing valve for an air respirator according to claim 5, characterized in that, The medium-pressure interface is equipped with a safety valve, which includes a valve body, a piston ring, and a safety valve spring. The piston ring and the safety valve spring are both sleeved on the valve body. The two ends of the safety valve spring abut against the piston ring and the valve body, respectively. A pressure relief port is provided on the valve body at the port position of the medium-pressure interface.

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