Pressure reducing valve with adjustable output pressure

Abstract

The invention relates to a pressure reducing valve with adjustable output pressure. The pressure reducing valve comprises a first-stage pressure reducing system, a second-stage pressure reducing system and a pressure adjusting module, the first-stage pressure reducing system, the second-stage pressure reducing system and the pressure regulating module are respectively arranged in a first port of the shell, a second port of the shell and a third port of the shell; the pressure regulating device is characterized in that the pressure regulating module comprises a pressure regulating elastic body and a rotatable end cover; an inner hole of the pressure-regulating elastomer is in clearance fit with a guide section of the elastomer guide sleeve, and the upper and lower end faces of the pressure-regulating elastomer are respectively pressed on the bottom of the third port and a flange of the elastomer guide sleeve; and the rotatable end cover is connected with the threaded section of the third port through the thread of the rotatable end cover. According to the pressure reducing valve, the direct pressure regulating function in the actual installation state can be achieved, the pressure reducing valve and any pipeline or assembly connected with the pressure reducing valve do not need to be disassembled, the pressure regulating operation is simple, and the problem that direct pressure regulating is difficult after the two-stage forward acting type pressure reducing valve is actually installed is solved.

Description

[Technical field]

[0001] The present invention relates to the technical field of pressure reducing valves, in particular to a pressure reducing valve with adjustable output pressure, in particular to a pressure reducing valve which is used to reduce the outlet pressure in a gas supply system with a large pressure difference and has an adjustable outlet pressure. [Background technology]

[0002] Pressure reducing valves are mainly used to adjust the high-pressure gas at the supply end with large pressure fluctuations to the low-pressure gas with stable pressure required by the application end, playing the role of reducing and stabilizing pressure. For example, in hydrogen energy vehicles, the pressure of the hydrogen storage tank at the hydrogen supply end can be as high as 70MPa, while the input pressure of the fuel cell system at the application end generally does not exceed 2MPa. Therefore, the pressure reducing valve must be used to reduce the pressure of the gas.

[0003] In order to achieve the decompression effect of high pressure (especially above 35MPa) and keep the output pressure relatively stable, the positive-acting two-stage decompression method is currently a more mainstream decompression solution.

[0004] However, the principle of pressure reduction determines the structural characteristics of the pressure reducing valve. This type of forward-acting two-stage system pressure reducing valve usually has a fixed pressure output form, that is, the pressure is adjusted according to customer needs when leaving the factory. Once installed in the pipeline system, the output pressure adjustment demand cannot be achieved on site, and the valve parts can only be disassembled and adjusted in the factory. However, in many cases, it is necessary to adjust the required pressure conveniently. For example, in the assembly and debugging of fuel cell new energy vehicle systems, since there is sometimes a certain deviation between the preliminary design and the actual product, it is necessary to fine-tune the gas supply pressure appropriately to achieve the most ideal working state. Although this type of pressure adjustment demand can be achieved through factory debugging, the entire process involves cumbersome system disassembly and high time costs, so there are great difficulties in actual operation.

[0005] Therefore, there is a need for an improved forward-acting two-stage system pressure reducing valve that can directly adjust the output pressure under actual installation conditions. [Summary of the invention]

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a pressure reducing valve with adjustable output pressure.

[0007] The principle of this application is mainly as follows: First, both the two-stage pressure reducing system adopts a forward-acting pressure reducing structure, a pressure regulating module is set between the first-stage pressure reducing system and the second-stage pressure reducing system, and the position of the valve seat of the second-stage pressure reducing system is adjusted by rotating the rotatable end cover outside the pressure regulating module, and finally the output pressure can be adjusted in both directions. The pressure reducing valve of this application can realize the direct pressure regulating function in the actual installation state, without the need to disassemble the pressure reducing valve and any pipelines or components connected to it, and the pressure regulating operation is simple, which solves the problem that it is difficult to directly regulate the pressure of the two-stage forward-acting pressure reducing valve after actual installation.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] A pressure reducing valve with adjustable output pressure, comprising a primary pressure reducing system, a secondary pressure reducing system, and a pressure regulating module; the primary pressure reducing system, the secondary pressure reducing system, and the pressure regulating module are respectively arranged in a first port of a shell, a second port of the shell, and a third port of the shell; the pressure regulating module comprises a pressure regulating elastomer, an elastomer guide sleeve, a pressure regulating module sealing ring, a secondary pressure pad, and a rotatable end cover, etc.;

[0010] The inner hole of the pressure regulating elastic body is clearance-matched with the guide section of the elastic body guide sleeve, and the upper and lower end surfaces thereof are respectively pressed against the bottom of the third port and the flange of the elastic body guide sleeve;

[0011] The rotatable end cap is connected to the threaded section of the third port through its thread. The output pressure can be adjusted by adjusting the rotatable end cap in the pressure regulating module to achieve bidirectional adjustment of the increase and decrease of the output pressure, which is the main difference between the present application and the prior art.

[0012] The shell is provided with three ports, a connecting channel and a connecting hole, which are respectively a first port, a second port, a third port, a connecting channel and a connecting hole;

[0013] The central axes of the second port, the third port and the connecting hole coincide with each other and the second port and the third port are connected through the connecting hole, and the connecting hole is connected with the first port through the connecting channel; the central axis of the first port is perpendicular or inclined to the central axes of the second port and the third port, and the angle range is 45° to 135°;

[0014] The third port includes an elastomer containing section, a guide sealing section and a threaded section, and the central axes of the three coincide with each other.

[0015] The guide section of the rotatable end cover is matched with the guide sealing section of the third port with a small gap, so that the rotatable end cover is coaxial with the third port.

[0016] The pressure regulating module sealing ring is arranged in the annular groove of the rotatable end cover and is in close contact with the third port guide sealing section;

[0017] The secondary pressure pad is divided into a large diameter part and a small diameter part, wherein the large diameter part is arranged in the guide hole on the rotatable end cover and cooperates with the small clearance therewith;

[0018] The axial dimension of the large diameter portion of the secondary pressure pad is greater than the depth of the guide hole of the rotatable end cover, so that the large diameter portion is not completely sunk into the guide hole;

[0019] The elastic guide sleeve is provided with a flange and a guide section, the end face of the flange is pressed tightly on the large diameter part of the secondary pressure pad, and the center hole of the guide section is sleeved on the outer periphery of the small diameter part of the secondary pressure pad and matched with it with a small gap.

[0020] The outer periphery of the guide section and the connecting hole of the shell are matched with a small gap;

[0021] The inner hole of the pressure regulating elastic body is clearance-matched with the guide section of the elastic body guide sleeve, and the upper and lower end surfaces thereof are respectively pressed tightly on the bottom of the third port and the flange of the elastic body guide sleeve.

[0022] A torque transmission structure is provided at one end of the rotatable end cover away from the guide hole;

[0023] The rotatable end cover is connected to the threaded section of the third port by a thread. When an external force is applied to the torque transmission structure of the rotatable end cover to rotate it, the rotatable end cover can be moved axially along the central axis of the pressure regulating module, and thereby drive the secondary pressure pad to move axially along the central axis of the pressure regulating module; the secondary pressure reducing system reduces pressure through the throttling area formed by the rod end face of the secondary active element and the end face of the small diameter portion of the secondary pressure pad. When the secondary pressure pad moves axially along the central axis of the pressure regulating module, the area of ​​the throttling area formed by the rod end face of the secondary active element and the end face of the small diameter portion of the secondary pressure pad is changed, thereby changing the output pressure of the secondary pressure reducing system, and the output pressure of the pressure reducing valve is changed by rotating the rotatable end cover.

[0024] An indicating arrow is provided at one end of the rotatable end cover away from the guide hole, and an output pressure indicating scale is provided on the periphery of the third port. According to the calculation and debugging results, an output pressure value is set on the corresponding scale. When the indicating arrow indicates a certain scale, the pressure reducing valve will output the pressure value shown on the corresponding scale when working.

[0025] The pressure regulating elastic body is in a compressed state and is pressed against the flange of the elastic body guide sleeve, so that the flange of the elastic body guide sleeve is pressed against the large diameter portion of the secondary pressure pad, and finally the secondary pressure pad is mechanically clamped between the rotatable end cover and the flange of the elastic body guide sleeve, and sinks into the guide hole of the rotatable end cover;

[0026] Since the pressure regulating elastic body is in a compressed state, the thread of the rotatable end cover is forced to fit tightly with the thread of the threaded section of the third port.

[0027] When pressure regulation is not required, the pressure regulating module of the pressure reducing valve is changed to a non-elastic fixed structure, that is, the pressure regulating elastomer is changed to an incompressible non-elastic body, which is set as an independent part or as a structure integrated with the shell or the elastomer guide sleeve.

[0028] Working status of this application:

[0029] When the pressure reducing valve is working, the external high-pressure gas first enters the primary pressure reducing system and becomes the primary pressure reducing gas, and then flows through the connecting channel to the secondary pressure reducing system for final pressure reduction, and then flows to the subsequent working system of the pressure reducing valve. In order to realize the pressure regulating function, a pressure regulating module is arranged between the primary pressure reducing system and the secondary pressure reducing system, and the position of the valve seat of the secondary pressure reducing system is adjusted by rotating the rotatable end cover outside the pressure regulating module, so as to finally realize the two-way regulation of the increase and decrease of the output pressure. At the third port of the shell where the pressure regulating module is located, there is an output pressure indicating scale, and the pressure regulating module can be adjusted according to the output pressure indicating scale, so that the required gas pressure can be obtained more conveniently.

[0030] Compared with the prior art, the present invention has the following positive effects:

[0031] The pressure-adjustable pressure reducing valve of the present invention can not only meet the pressure adjustment requirements under actual installation conditions, but also realize efficient calibration of pressure parameters of internal mass-produced products without disassembly.

Brief Description of the Drawings

[0032] Figure 1 It is a schematic diagram of the overall structure of a two-stage system pressure reducing valve with adjustable output pressure according to the present invention;

[0033] Figure 2 Schematic diagram of the output pressure indicating scale of the pressure reducing valve of the present invention;

[0034] Figure 3 It is a schematic diagram of the structure of a rotatable end cover, one of the parts of the pressure reducing valve of the present invention;

[0035] Figure 4 It is a schematic structural diagram of an elastic guide sleeve, one of the parts of the pressure reducing valve of the present invention;

[0036] Figure 5 It is a schematic diagram of the structure of a secondary pressure pad, which is one of the components of the pressure reducing valve of the present invention;

[0037] Figure 6-7 They are all schematic diagrams of a two-stage system pressure reducing structure in which the output pressure is not adjustable;

[0038] Figures 1 to 7The contents marked with serial numbers are as follows: first-stage pressure reducing system (1), housing (2), second-stage pressure reducing system (3), pressure regulating module (4), inlet end cover (5), first-stage pressure pad (6), first-stage spring (7), first-stage front end sealing ring (8), first-stage front end guide ring (9), first-stage valve core (10), first-stage rear end guide ring (11), first-stage rear end sealing ring (12), outlet end cover (13), second-stage rear end sealing ring (14), second-stage rear end guide ring (15), second-stage valve core (16), second-stage spring (17), second-stage front end guide ring (18), second-stage guide flange (19), second-stage front end sealing ring (20), pressure regulating elastic body (21), pressure regulating module sealing ring (22), elastic body guide sleeve (23), second-stage pressure pad (24), rotatable End cover (25), first port (2.1), second port (2.2), third port (2.3), third port elastomer accommodating section (2.3.1), third port guide sealing section (2.3.2), third port thread section (2.3.3), connecting channel (2.4), connecting hole (2.5), indicating scale (2.6), non-elastic body (21.1), guide sleeve flange (23.1), guide sleeve guide section (23.2), secondary pressure pad large diameter section (24.1), secondary pressure pad small diameter section (24.2), rotatable end cover thread (25.1), rotatable end cover guide section (25.2), rotatable end cover annular groove (25.3), rotatable end cover torque transmission structure (25.4), rotatable end cover guide hole (25.5). [Specific implementation method]

[0039] A specific implementation of a pressure reducing valve with adjustable output pressure according to the present invention is provided below.

[0040] Example 1

[0041] Two-stage system pressure reducing valve with adjustable output pressure Figures 1 to 5 , its overall structure includes a primary pressure reducing system 1, a secondary pressure reducing system 3, a pressure regulating module 4, a shell 2 and other parts; the shell 2 is provided with three ports, a connecting channel and a connecting hole, which are a first port 2.1, a second port 2.2, a third port 2.3, a connecting channel 2.4, and a connecting hole 2.5; wherein the central axes of the second port 2.2 and the third port 2.3 coincide and are connected through the connecting hole 2.5, and the connecting hole 2.5 is connected with the first port 2.1 through the connecting channel 2.4; the central axis of the first port 2.1 is perpendicular to the central axes of the second port 2.2 and the third port 2.3, so that the overall structure of the pressure reducing valve is "L-shaped" or "T-shaped"; the primary pressure reducing system 1, the secondary pressure reducing system 3, and the pressure regulating module 4 are respectively arranged in the first port 2.1, the second port 2.2, and the third port 2.3, and are respectively coaxial with the corresponding ports;

[0042] The first-stage decompression system 1 includes an inlet end cover 5, a first-stage pressure pad 6, a first-stage spring 7, a first-stage front-end sealing ring 8, a first-stage front-end guide ring 9, a first-stage valve core 10, a first-stage rear-end guide ring 11, a first-stage rear-end sealing ring 12 and other parts; the second-stage decompression system 3 includes an outlet end cover 13, a second-stage rear-end sealing ring 14, a second-stage rear-end guide ring 15, a second-stage valve core 16, a second-stage spring 17, a second-stage front-end guide ring 18, a second-stage guide flange 19, and a second-stage front-end sealing ring 20; the pressure regulating module 4 includes: a pressure regulating elastomer 21, an elastomer guide sleeve 23, a pressure regulating module sealing ring 22, a second-stage pressure pad 24, a rotatable end cover 25 and other parts; the third port 2.3 includes: an elastomer accommodating section 2.3.1, a guide sealing section 2.3.2, a threaded section 2.3.3, etc., and the central axes of the three coincide.

[0043] When the pressure reducing valve is working, the external high-pressure gas first enters the primary pressure reducing system, and is converted into the primary pressure reducing gas through the mutual force between a series of parts and the gas in the primary pressure reducing system, and then flows into the secondary pressure reducing system through the connecting channel 2.4 for final pressure reduction, and then flows into the subsequent working system of the pressure reducing valve; when the output pressure is not the required pressure, the required output pressure can be obtained by adjusting the pressure regulating module 4.

[0044] The specific structure and voltage regulation method of the voltage regulation module 4 are described in detail as follows.

[0045] The rotatable end cover 25 is connected to the threaded section 2.3.3 of the third port 2.3 through its thread 25.1, and its guide section 25.2 is matched with the guide sealing section 2.3.2 of the third port 2.3 with a small gap, so that the rotatable end cover 25 and the third port 2.3 are basically coaxial; the pressure regulating module sealing ring 22 is arranged in the annular groove 25.3 of the rotatable end cover 25, and is tightly attached to the guide sealing section 2.3.2 of the third port 2.3 to achieve sealing; the secondary pressure pad 24 is divided into a large diameter part 24.1 and a small diameter part 24.2, and its large diameter part 24.1 is arranged in the guide hole 25.5 on the rotatable end cover 25 and is matched with it with a small gap; the axial size of the large diameter part 24.1 of the secondary pressure pad 24 is greater than the depth of the guide hole on the rotatable end cover 25, so that the large diameter part 24.1 is not completely sunk into the guide hole 25.5; the elastic body guide sleeve 23 is provided There are flange 23.1 and guide section 23.2, the end face of flange 23.1 is pressed on the large diameter part 24.1 of secondary pressure pad 24, the center hole of guide section 23.2 is sleeved on the periphery of small diameter part 24.2 of secondary pressure pad 24 and matched with it with a small gap, and the periphery of guide section 23.2 is matched with the connecting hole 2.5 of shell 2 with a small gap; the inner hole of pressure regulating elastic body 21 is matched with the guide section 23.2 of elastic body guide sleeve 23 with a gap, and is in a compressed state, and the upper and lower end faces are pressed on the bottom of the third port 2.3 and the flange 23.1 of elastic body guide sleeve 23 respectively, so that the flange 23.1 of elastic body guide sleeve 23 is pressed on the large diameter part 24.1 of secondary pressure pad 24, and finally the secondary pressure pad 24 is clamped between the rotatable end cover 25 and the flange 23.1 of elastic body guide sleeve 23, and sinks into the guide hole 25.5 of the rotatable end cover 25.

[0046] The end of the rotatable end cover 25 away from the guide hole 25.5 is provided with circumferentially distributed circular holes 25.4, which are torque transmission structures. Since the rotatable end cover 25 is connected with the threaded section 2.3.3 of the third port 2.3 by threads, when an external force is applied to the torque transmission structure 25.4 of the rotatable end cover 25 to rotate it, the rotatable end cover 25 can be moved axially along the central axis of the pressure regulating module 4, and the secondary pressure pad 24 can be driven to move axially along the central axis of the pressure regulating module 4. The secondary pressure reducing system reduces pressure through the throttling area formed by the rod end face of the secondary active element 16 and the small diameter end face of the secondary pressure pad 24. When the secondary pressure pad 24 moves axially along the central axis of the pressure regulating module 4, the area of ​​the throttling area formed by the rod end face of the secondary active element 16 and the small diameter end face of the secondary pressure pad 24 is changed, thereby changing the output pressure of the secondary pressure reducing system, that is, changing the output pressure of the pressure reducing valve of the present invention. In addition, since the pressure-regulating elastomer 21 is in a compressed state, the threads connecting the rotatable end cover 25 and the threaded section 2.3.3 of the third port 2.3 are forced to fit tightly, thereby increasing the friction between the threads of the two, making it difficult for the rotatable end cover 25 to rotate without a sufficiently large external force, that is, it is not easy to cause unexpected changes in the output pressure, thereby ensuring the reliability and safety of the pressure reducing valve.

[0047] In order to conveniently and intuitively know the change of output pressure during pressure regulation, an indicating arrow 25.5 is provided at one end of the rotatable end cover 25 away from the guide hole 25.5, and an output pressure indicating scale 2.6 is provided on the periphery of the third port 2.3, as shown in FIG. Figure 2 As shown; in practical applications, the output pressure value can be set on the corresponding scale according to the calculation and debugging results. When the rotatable end cover 25 is rotated so that the indicating arrow 25.5 indicates a certain scale, the displayed value of the certain scale is the pressure value output by the pressure reducing valve;

[0048] In summary, when adjusting the pressure of the pressure reducing valve of the present invention, there is no need to disassemble the pressure reducing valve of the present invention and any structure connected thereto, and the pressure adjustment can be achieved by directly adjusting the rotatable end cover on the pressure reducing valve, and the pressure adjustment has the advantages of convenience, safety, reliability, and intuitiveness.

[0049] Example 2

[0050] The difference between the pressure reducing valve embodiment 2 of the present invention and embodiment 1 is that the central axis of the first port 2.1 is not perpendicular to the central axes of the second port 2.2 and the third port 2.3, but forms an angle less than 90 degrees or greater than 90 degrees, so that the overall structure of the pressure reducing valve of the present invention is "V"-shaped or "へ"-shaped.

[0051] Example 3

[0052] The difference between Example 3 of the pressure reducing valve of the present invention and Example 1 is that the pressure regulating elastomer 21 is composed of one or more spiral springs connected in series or in parallel, all of which are in a compressed state and are sheathed on the periphery of the guide section 23.2 of the guide sleeve 23 or are evenly distributed circumferentially around the guide section 23.2 of the elastomer guide sleeve 23, and are pressed against the flange 23.1 of the elastomer guide sleeve 23, so that the elastomer guide sleeve 23 is subjected to symmetrical axial pressing force.

[0053] Example 4

[0054] The difference between Example 4 of the pressure reducing valve of the present invention and Example 1 is that the torque transmission structure 25 . 4 is a regular polygonal boss or a recessed hole, and the central axis of the regular polygonal boss or the recessed hole is coaxial with the rotatable end cover 25 .

[0055] Example 5

[0056] The difference between the pressure reducing valve embodiment 5 of the present invention and the embodiment 1 is that Figure 6 The pressure regulating elastic body 21 is changed into an incompressible non-elastic body 21.1, which is a metal ring. During installation, the rotatable end cover 25 needs to be tightened to press the non-elastic body 21.1, the guide sleeve 23, the secondary pressure pad 24, and the rotatable end cover 25 in sequence, and finally press them on the bottom of the third port 2.3. After installation, the rotatable end cover 25 cannot be loosened. At this time, the secondary pressure pad 24 can no longer move axially along the third port 2.3. In this case, the output pressure of the valve member cannot be adjusted. This non-pressure-adjustable structure is a special structure of the pressure reducing valve of the present invention.

[0057] Example 6

[0058] The difference between the pressure reducing valve embodiment 6 of the present invention and the embodiments 1 and 5 is that Figure 7 The pressure regulating elastic body 21 is changed into an incompressible non-elastic body 21.2 and integrated with the housing 2, and a transverse through hole 21.3 is provided at the end, and the connecting hole 2.5 is connected with the connecting channel 2.4 through the through hole 21.3, the third port 2.3 and the like.

[0059] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the concept of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A pressure reducing valve with adjustable output pressure, comprising a primary pressure reducing system (1), a secondary pressure reducing system (3), and a pressure regulating module (4); the primary pressure reducing system, the secondary pressure reducing system, and the pressure regulating module are respectively arranged in a first port (2.1) of a housing, a second port (2.2) of the housing, and a third port (2.3) of the housing; characterized in that: The pressure regulating module comprises a pressure regulating elastic body (21), an elastic body guide sleeve (23), a pressure regulating module sealing ring (22), a secondary pressure pad (24) and a rotatable end cover (25); The inner hole of the pressure regulating elastic body is clearance-matched with the guide section (23.2) of the elastic body guide sleeve (23), and the upper and lower end surfaces thereof are respectively pressed against the bottom of the third port (2.3) and the flange (23.1) of the elastic body guide sleeve (23); The rotatable end cover is connected to the threaded section (2.3.3) of the third port (2.3) via its thread (25.1).

2. A pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: The housing (2) is provided with three ports, a connecting channel and a connecting hole, namely a first port (2.1), a second port (2.2), a third port (2.3), a connecting channel (2.4) and a connecting hole (2.5); The central axes of the second port (2.2), the third port (2.3) and the connecting hole (2.5) coincide with each other, and the second port (2.2) and the third port (2.3) are connected through the connecting hole (2.5), and the connecting hole (2.5) is connected with the first port (2.1) through the connecting channel (2.4); the central axis of the first port (2.1) is perpendicular or inclined to the central axes of the second port (2.2) and the third port (2.3), and the angle range is 45° to 135°.

3. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: The third port (2.3) comprises an elastomer containing section (2.3.1), a guide sealing section (2.3.2) and a threaded section (2.3.3), and the central axes of the three coincide with each other.

4. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: The guide section (25.2) of the rotatable end cover (25) is matched with the guide sealing section (2.3.2) of the third port (2.3) with a small gap, so that the rotatable end cover (25) and the third port (2.3) are coaxial.

5. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: The pressure regulating module sealing ring (22) is arranged in the annular groove (25.3) of the rotatable end cover (25) and is in close contact with the guide sealing section (2.3.2) of the third port (2.3); The secondary pressure pad (24) is divided into a large diameter portion (24.1) and a small diameter portion (24.2), wherein the large diameter portion (24.1) is arranged in a guide hole (25.5) on a rotatable end cover (25) and is matched with a small clearance therewith; The axial dimension of the large diameter portion (24.1) of the secondary pressure pad (24) is greater than the depth of the guide hole (25.5) of the rotatable end cover (25), so that the large diameter portion (24.1) is not completely sunk into the guide hole (25.5); The elastic guide sleeve (23) is provided with a flange (23.1) and a guide section (23.2). The end face of the flange (23.1) is pressed tightly against the large diameter portion (24.1) of the secondary pressure pad (24). The center hole of the guide section (23.2) is sleeved around the outer periphery of the small diameter portion (24.2) of the secondary pressure pad (24) and is matched with the small clearance therebetween. The periphery of the guide section (23.2) is matched with the connecting hole (2.5) of the housing (2) with a small clearance; The inner hole of the pressure regulating elastic body (21) is clearance-matched with the guide section (23.2) of the elastic body guide sleeve (23), and its upper and lower end surfaces are respectively pressed against the bottom of the third port (2.3) and the flange (23.1) of the elastic body guide sleeve (23).

6. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: A torque transmission structure (25.4) is provided at one end of the rotatable end cover (25) away from the guide hole (25.5); The rotatable end cover (25) is threadedly connected to the threaded section (2.3.3) of the third port (2.3). When an external force is applied to the torque transmission structure (25.4) of the rotatable end cover (25) to rotate it, the rotatable end cover (25) can be moved axially along the central axis of the pressure regulating module (4), thereby driving the secondary pressure pad (24) to move axially along the central axis of the pressure regulating module (4); the secondary pressure reducing system reduces pressure through the throttling area formed by the rod end face of the secondary movable element (16) and the small diameter end face of the secondary pressure pad (24). When the secondary pressure pad (24) moves axially along the central axis of the pressure regulating module (4), the area of ​​the throttling area formed by the rod end face of the secondary movable element (16) and the small diameter end face of the secondary pressure pad (24) is changed, thereby changing the output pressure of the secondary pressure reducing system. The output pressure of the pressure reducing valve can be changed by rotating the rotatable end cover (25).

7. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: An indicating arrow (25.6) is provided at one end of the rotatable end cover (25) away from the guide hole (25.5), and an output pressure indicating scale (2.6) is provided on the periphery of the third port (2.3). According to calculation and debugging results, an output pressure value is provided on the corresponding scale. When the indicating arrow (25.6) indicates a certain scale, the pressure reducing valve will output the pressure value indicated by the corresponding scale when working.

8. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: The pressure regulating elastomer (21) is in a compressed state and is pressed against the flange (23.1) of the elastomer guide sleeve (23), so that the flange (23.1) of the elastomer guide sleeve (23) is pressed against the large diameter portion (24.1) of the secondary pressure pad (24), and finally the secondary pressure pad (24) is mechanically clamped between the rotatable end cover (25) and the flange (23.1) of the elastomer guide sleeve (23), and sinks into the guide hole (25.5) of the rotatable end cover (25).

9. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: Since the pressure regulating elastic body (21) is in a compressed state, the thread (25.1) of the rotatable end cover (25) is forced to fit tightly with the thread of the threaded section (2.3.3) of the third port (2.3).

10. The pressure reducing valve with adjustable output pressure according to claim 1, characterized in that: When pressure regulation is not required, the pressure regulating module of the pressure reducing valve can be changed to a non-elastic fixed structure, that is, the pressure regulating elastomer (21) is changed to an incompressible non-elastic body (21.1), and the non-elastic body (21.1) is set as an independent part, or is set as a structure integrated with the shell (2) or the elastomer guide sleeve (23).

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