Servo relief valve, servo control system and diaphragm compressor system

Abstract

The present application discloses a follow-up relief valve, a follow-up control system and a diaphragm compressor system, wherein the follow-up relief valve includes a valve cover, a valve body, an air piston, an oil piston, a valve stem, a valve core and a pressure regulating spring, and the follow-up control system also includes a pressure transmitter and an electric proportional valve, wherein the pressure transmitter is used to be connected to the diaphragm compressor, the electric proportional valve is connected to the pressure transmitter to receive the electric signal, the electric proportional valve is connected to the follow-up relief valve, and the pressure value of the compressed gas is inversely proportional to the value of the received electric signal. The diaphragm compressor system of the embodiment of the present application breaks the structure of the diaphragm follow-up valve, avoids the use of the diaphragm follow-up relief valve in the related art to achieve the follow-up between the exhaust pressure of the diaphragm compressor and the overflow pressure of the oil side diaphragm chamber, can ensure the follow-up of the oil and gas pressure, and does not need to add an additional set of diaphragm structure, reduces the complexity and failure rate of the system, and increases the safety and stability of the system.

Description

Technical Field

[0001] The present application relates to the technical field of diaphragm compressors, and in particular to a follow-up overflow valve, a follow-up control system and a diaphragm compressor system. Background Art

[0002] The diaphragm compressor is a basic working unit composed of a group of diaphragms compressed by a cylinder body and an oil cylinder body. The air-side diaphragm cavity is formed between the cylinder body and the diaphragm, and the oil-side diaphragm cavity is formed between the oil cylinder body and the diaphragm. A piston is also arranged in the oil cylinder body. The piston reciprocates in the oil cylinder body and pushes the hydraulic oil in the oil-side diaphragm cavity to move at the same time. The hydraulic oil pushes the diaphragm to deform to complete the compression and exhaust of the gas in the air-side diaphragm cavity.

[0003] In the related art, in order to prevent the pressure difference between the air side diaphragm chamber and the oil side diaphragm chamber from being too large during each cycle of the diaphragm compressor and thus affecting the service life of the diaphragm, a diaphragm type follow-up overflow valve is arranged between the air side diaphragm chamber and the oil side diaphragm chamber. This overflow valve can change the overflow oil pressure with the exhaust pressure, so as to prevent the pressure difference between the air side diaphragm chamber and the oil side diaphragm chamber from being too large during each cycle of the diaphragm compressor and thus affecting the service life of the diaphragm. However, this diaphragm type follow-up overflow valve is similar to a small diaphragm machine, which is equivalent to adding another set of diaphragm structure to the entire diaphragm compressor system. However, the diaphragm is a vulnerable part, resulting in a high failure rate of the diaphragm compressor. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiments of the present application propose a follow-up overflow valve to reduce the failure rate of the diaphragm compressor, the embodiments of the present application propose a follow-up control system to reduce the failure rate of the diaphragm compressor, and the embodiments of the present application propose a diaphragm compressor system to reduce the failure rate of the diaphragm compressor.

[0005] The follower overflow valve of the embodiment of the present application comprises a valve cover, a valve body, an air piston, an oil piston, a valve stem, a valve core and a pressure regulating spring, wherein the valve cover is threadedly connected to the valve body, the valve cover has an air inlet, and the valve body has an oil overflow cavity, an oil inlet and an oil overflow port;

[0006] The gas piston is movably arranged in the valve cover along the axial direction of the valve body, at least a part of the oil piston is arranged in the oil overflow chamber and is movable along the axial direction of the valve body, a low-pressure chamber is defined between the gas piston and the valve cover, a high-pressure chamber is defined between the gas piston, the valve cover and the oil piston, the gas inlet is communicated with the high-pressure chamber, a first stop portion is provided in the valve cover between the gas piston and the oil piston, the oil piston stops on the first stop portion, and a first through hole is provided on the oil piston extending along the axial direction of the valve body;

[0007] The first end of the valve stem passes through the first through hole and is connected to the gas piston, the second end of the valve stem is placed in the oil overflow chamber and is connected to the valve core, the valve core is used to block the oil inlet, and the valve stem is provided with a second stop portion; the pressure regulating spring is sleeved on the valve stem and the two ends of the pressure regulating spring are respectively stopped on the oil piston and the second stop portion.

[0008] In some embodiments, the valve cover has a vent hole connected to the low-pressure chamber, and the vent hole is used to communicate with the atmospheric environment.

[0009] In some embodiments, the oil piston has a accommodating cavity and a first opening, the first opening is arranged toward the valve core in the axial direction of the valve body, and at least a portion of the pressure regulating spring is arranged in the accommodating cavity.

[0010] In some embodiments, the follower relief valve of the embodiment of the present application further includes a bushing and a cushion block, wherein the bushing is located in the accommodating cavity and sleeved on the valve stem, and one end of the bushing away from the valve core in the axial direction of the valve body abuts against the cavity wall of the accommodating cavity;

[0011] The cushion block has a second through hole extending along the axial direction of the valve body. The cushion block is sleeved on the valve stem through the second through hole and is arranged between the bushing and the pressure regulating spring. The two ends of the cushion block in the axial direction of the valve body respectively abut against the bushing and the pressure regulating spring.

[0012] In some embodiments, the follow-up relief valve of the embodiment of the present application also includes a connecting head, which is arranged on the valve body and is used to connect to the diaphragm compressor. The connecting head has an oil passage, a channel inlet and a channel outlet, and the channel inlet is connected to the oil inlet.

[0013] In some embodiments, the follow-up relief valve of the embodiment of the present application also includes a connecting block, which is connected to the valve stem, and the connecting block has a groove opening toward the oil inlet. The valve core is a sphere, and a part of the valve core is placed in the groove and connected to the connecting block.

[0014] The servo control system of the embodiment of the present application includes the servo overflow valve described in any of the above embodiments.

[0015] The servo control system of the embodiment of the present application further includes a pressure transmitter and an electrical proportional valve, wherein the pressure transmitter is used to be connected to the diaphragm compressor to receive the exhaust pressure of the diaphragm compressor and convert the exhaust pressure into an electrical signal;

[0016] The electrical proportional valve is connected to the pressure transmitter to receive the electrical signal, and the electrical proportional valve is connected to the follow-up relief valve to deliver compressed gas to the high-pressure chamber of the follow-up relief valve. The pressure value of the compressed gas is inversely proportional to the value of the received electrical signal.

[0017] In some embodiments, the servo control system of the embodiment of the present application also includes a gas tank, the electrical proportional valve includes a controller, a gas inlet and a gas outlet, the controller is connected to the pressure transmitter to receive the electrical signal output by the pressure transmitter, the gas inlet is connected to the gas tank, and the gas outlet is connected to the air inlet of the servo overflow valve.

[0018] The diaphragm compressor system of the embodiment of the present application includes a diaphragm compressor and a servo control system, and the servo control system is the servo control system described in any of the above embodiments.

[0019] When the diaphragm compressor system of the embodiment of the present application is working, when the exhaust pressure of the exhaust valve of the diaphragm compressor changes, the overflow oil pressure of the oil-side diaphragm chamber can change synchronously with the change of the exhaust pressure of the exhaust valve of the diaphragm compressor, so that the overflow oil pressure in the oil-side diaphragm chamber can follow the exhaust pressure of the exhaust valve, and realize the automatic bypass function of the follow-up overflow valve. Therefore, the diaphragm compressor system of the embodiment of the present application breaks the structure of the diaphragm follow-up valve, avoids the use of the diaphragm follow-up overflow valve in the related technology to achieve the follow-up between the exhaust pressure of the diaphragm compressor and the overflow oil pressure of the oil-side diaphragm chamber, can ensure the follow-up of the oil and gas pressure, and does not need to add an additional set of diaphragm structure, reducing the complexity and failure rate of the system and increasing the safety and stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a diaphragm compressor in the related art.

[0021] Figure 2 Schematic diagram of a diaphragm compressor system according to an embodiment of the present application.

[0022] Figure 3 It is a schematic diagram of the structure of the follow-up overflow valve of an embodiment of the present application.

[0023] Reference numerals:

[0024] 1000, diaphragm compressor system; 300, follow-up control system; 200, diaphragm compressor; 100, follow-up overflow valve; 1, valve cover; 101, air inlet; 102, first stop portion; 103, vent; 2, valve body; 201, oil overflow chamber; 202, oil inlet; 203, oil overflow port; 3, air piston; 4, oil piston; 401, first perforation; 402, accommodating chamber; 403, first opening; 5, low-pressure chamber ; 6. High-pressure chamber; 7. Valve stem; 701. First end; 702. Second end; 8. Valve core; 9. Pressure regulating spring; 10. Bushing; 11. Spacer; 1101. Second perforation; 12. Connector; 1201. Oil passage; 13. Connecting block; 1301. Groove; 14. Pressure transmitter; 15. Electric proportional valve; 1501. Controller; 1502. Gas inlet; 1503. Gas outlet; 16. Gas tank;

[0025] 20. Air side diaphragm chamber; 21. Oil side diaphragm chamber; 22. Diaphragm; 23. Piston; 24. Inlet valve; 25. Exhaust valve; 26. Oil supply valve; 27. Overflow valve. DETAILED DESCRIPTION

[0026] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application.

[0027] like Figure 1 As shown, the diaphragm compressor in the related art includes an air-side diaphragm chamber 20 , an oil-side diaphragm chamber 21 , a diaphragm 22 , a piston 23 , an intake valve 24 , an exhaust valve 25 , an oil replenishment valve 26 and a relief valve 27 .

[0028] When the piston 23 moves from the lower dead center to the upper dead center, the piston 23 pushes the hydraulic oil in the oil-side diaphragm chamber 21 to be compressed, and the hydraulic oil in the oil-side diaphragm chamber 21 pushes the diaphragm 22 to deform upward. At this time, the hydraulic oil in the oil-side diaphragm chamber 21 and the gas in the gas-side diaphragm chamber 20 are compressed together. As the piston 23 moves further upward, the pressure of the compressed gas in the gas-side diaphragm chamber 20 is greater than the opening pressure of the exhaust valve 25, and the exhaust valve 25 opens to start the exhaust process. When the diaphragm 22 moves to the upper surface of the gas-side diaphragm chamber 20, the gas in the gas-side diaphragm chamber 20 is completely discharged, and the piston 23 has not reached the upper dead center at this time. As the piston 23 continues to move upward, the oil pressure in the oil-side diaphragm chamber 21 is greater than the oil discharge pressure of the relief valve 27, and the relief valve 27 opens to discharge the hydraulic oil in the oil-side diaphragm chamber 21 to reduce the oil pressure in the oil-side diaphragm chamber 21 and avoid overpressure, thus completing the gas compression process.

[0029] When the piston 23 moves from the top dead center to the bottom dead center, the diaphragm 22 separates from the upper surface of the gas side diaphragm chamber 20 and starts to move downward, the oil pressure in the oil side diaphragm chamber 21 decreases, the overflow valve 27 closes, the volume of the hydraulic oil in the oil side diaphragm chamber 21 increases and begins to expand, and the diaphragm 22 begins to deform downward under the action of the hydraulic oil. As the piston 23 continues to move downward, when the oil pressure in the oil side diaphragm chamber 21 continues to decrease, the intake valve 24 opens and starts to inhale. At the same time, during the inhalation process, the oil replenishment valve 26 injects a certain volume of hydraulic oil into the oil side diaphragm chamber 21 for replenishment.

[0030] In order to avoid the pressure difference between the gas side diaphragm chamber 20 and the oil side diaphragm chamber 21 being too large in each cycle and affecting the service life of the diaphragm 22, the diaphragm compressor in the related art sets the overflow valve 27 as a diaphragm type follow-up overflow valve and connects it to the exhaust valve 25. This diaphragm type follow-up overflow valve can realize the change of the overflow pressure with the change of the exhaust pressure, so as to avoid the pressure difference between the gas side diaphragm chamber 20 and the oil side diaphragm chamber 21 being too large in each cycle of the diaphragm compressor 200 and affecting the service life of the diaphragm 22. However, this diaphragm type follow-up overflow valve is similar to a small diaphragm machine, which is equivalent to adding another set of diaphragm 22 structure to the entire diaphragm compressor system. However, the diaphragm 22 is a vulnerable part, resulting in a high failure rate of the diaphragm compressor 200.

[0031] The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiment of the present application proposes a diaphragm compressor system 1000, which includes a diaphragm compressor 200 and a servo control system 300. The servo control system 300 includes a servo relief valve 100, a pressure transmitter 14 and an electric proportional valve 15.

[0032] The follow-up relief valve 100 includes a valve cover 1, a valve body 2, an air piston 3, an oil piston 4, a valve stem 7, a valve core 8 and a pressure regulating spring 9. The valve cover 1 is threadedly connected to the valve body 2, and the valve cover 1 has an air inlet 101, and the valve body 2 has an oil overflow chamber 201, an oil inlet 202 and an oil overflow port 203. The air piston 3 is movably arranged in the valve cover 1 along the axial direction of the valve body 2, and at least a part of the oil piston 4 is arranged in the oil overflow chamber 201 and is movable along the axial direction of the valve body 2. A low-pressure chamber 5 is defined between the air piston 3 and the valve cover 1, and a high-pressure chamber 6 is defined between the air piston 3, the valve cover 1 and the oil piston 4, and the air inlet 101 is connected to the high-pressure chamber 6.

[0033] The valve cover 1 has a first stop portion 102 located between the gas piston 3 and the oil piston 4. The oil piston 4 stops on the first stop portion 102. The oil piston 4 has a first through hole 401 extending along the axial direction of the valve body 2. The first end 701 of the valve stem 7 passes through the first through hole 401 and is connected to the gas piston 3. The second end 702 of the valve stem 7 is placed in the oil overflow chamber 201 and is connected to the valve core 8. The valve core 8 is used to block the oil inlet 202. The valve stem 7 has a second stop portion. The pressure regulating spring 9 is sleeved on the valve stem 7, and the two ends of the pressure regulating spring 9 stop on the oil piston 4 and the second stop portion respectively.

[0034] The pressure transmitter 14 is used to be connected to the diaphragm compressor 200 to receive the exhaust pressure of the diaphragm compressor 200 and convert the exhaust pressure into an electrical signal. The electrical proportional valve 15 is connected to the pressure transmitter 14 to receive the electrical signal. The electrical proportional valve 15 is connected to the follow-up relief valve 100 to deliver compressed gas to the high-pressure chamber 6 of the follow-up relief valve 100. The pressure value of the compressed gas is inversely proportional to the value of the received electrical signal.

[0035] When the diaphragm compressor system 1000 of the embodiment of the present application is working, the pre-compression amount of the pressure regulating spring 9 of the follower relief valve 100 is first adjusted, specifically as follows: Figure 3 As shown, the valve cover 1 is screwed downward to a preset thread engagement dimension, and the first stop portion 102 on the valve cover 1 pushes the oil piston 4 downward, and the oil piston 4 pushes the pressure regulating spring 9 downward. The pressure regulating spring 9 is compressed to a preset value to press the valve core 8 against the oil inlet 202, so that the valve core 8 seals the oil inlet 202.

[0036] When the exhaust valve 25 of the diaphragm compressor 200 is exhausting, the pressure transmitter 14 converts the exhaust pressure value of the diaphragm compressor 200 into an electrical signal and transmits it to the electrical proportional valve 15. The electrical proportional valve 15 outputs compressed gas of a certain pressure according to the size of the electrical signal, and transmits the compressed gas to the high-pressure chamber 6 of the follow-up relief valve 100 through the air inlet 101. In the high-pressure chamber 6, the compressed gas pushes the gas piston 3 upward. At this time, the combined force on the valve stem 7 = the preload force of the pressure regulating spring 9 - the thrust of the compressed gas on the gas piston 3. When the hydraulic oil pressure in the oil-side membrane chamber 21 is greater than the combined force on the valve stem 7, the hydraulic oil pushes the valve core 8 to enter the oil overflow chamber 201 and flows out through the oil overflow port 203, realizing the hydraulic oil pressure relief of the oil-side membrane chamber 21.

[0037] Since the pressure value of the compressed gas entering the high-pressure chamber 6 is inversely proportional to the value of the electrical signal received by the pressure transmitter 14, that is, when the exhaust pressure of the exhaust valve 25 of the diaphragm compressor 200 increases, the electrical signal transmitted by the pressure transmitter 14 to the electrical proportional valve 15 increases, the pressure of the compressed gas transmitted to the high-pressure chamber 6 by the electrical proportional valve 15 decreases, the resultant force on the valve stem 7 will increase, and the oil overflow pressure of the oil-side diaphragm chamber 21 will increase. Conversely, when the exhaust pressure of the exhaust valve 25 of the diaphragm compressor 200 decreases, the electrical signal transmitted by the pressure transmitter 14 to the electrical proportional valve 15 decreases, the pressure of the compressed gas transmitted to the high-pressure chamber 6 by the electrical proportional valve 15 increases, the resultant force on the valve stem 7 will decrease, and the oil overflow pressure of the oil-side diaphragm chamber 21 will decrease.

[0038] Therefore, when the exhaust pressure of the exhaust valve 25 of the diaphragm compressor 200 changes, the overflow oil pressure of the oil-side diaphragm chamber 21 can change synchronously with the change of the exhaust pressure of the exhaust valve 25 of the diaphragm compressor 200, so that the overflow oil pressure in the oil-side diaphragm chamber 21 and the exhaust pressure of the exhaust valve 25 can be followed, and the automatic bypass function of the follow-up overflow valve 100 is realized. Therefore, the diaphragm compressor system 1000 of the embodiment of the present application breaks the structure of the diaphragm follow-up valve, avoids the use of the diaphragm follow-up overflow valve in the related art to achieve the follow-up between the exhaust pressure of the diaphragm compressor 200 and the overflow oil pressure of the oil-side diaphragm chamber 21, can ensure the follow-up of the oil and gas pressure, and does not need to add an additional set of diaphragm structures, reducing the complexity and failure rate of the system, and increasing the safety and stability of the system.

[0039] In addition, since the diaphragm compressor 200 is in a relatively stable operating condition most of the time, the compressed gas in the high-pressure chamber 6 of the follow-up relief valve 100 basically does not need to make pressure adjustments. Even if the electrical proportional valve 15 fails due to power failure, the threaded connection between the valve cover 1 and the valve body 2 can ensure that the preload force of the pressure regulating spring 9 acting on the valve core 8 is a preset value, so that the diaphragm compressor 200 operates in a safe state, improving the working reliability of the diaphragm compressor system 1000. In addition, by converting the exhaust pressure into an electrical signal to ultimately control the oil overflow pressure, the compressed working medium in the gas-side membrane chamber 20 will not come into contact with the oil, completely avoiding the risk of contamination.

[0040] In some embodiments, the valve cover 1 has a vent hole 103 connected to the low-pressure chamber 5. The vent hole 103 is used to connect to the atmospheric environment so that the low-pressure chamber 5 is in a normal pressure state. When the gas piston 3 is only subjected to the thrust of the compressed gas in the high-pressure chamber 6 during operation, the resultant force on the valve stem 7 is easy to calculate.

[0041] In some embodiments, Figure 3As shown, the oil piston 4 has an accommodating chamber 402 and a first opening 403, the first opening 403 is arranged in the axial direction of the valve body 2 toward the valve core 8, and at least a part of the pressure regulating spring 9 is arranged in the accommodating chamber 402. In other words, a part of the pressure regulating spring 9 can be arranged in the accommodating chamber 402 through the first opening 403, or the entire pressure regulating spring 9 can be arranged in the accommodating chamber 402, so as to save the space volume of the follower relief valve 100 in the axial direction of the valve body 2, so as to make the structure compact.

[0042] In some embodiments, the follow-up relief valve 100 of the embodiment of the present application also includes a sleeve 10 and a gasket 11. The sleeve 10 is located in the accommodating chamber 402 and is sleeved on the valve stem 7. The end of the sleeve 10 away from the valve core 8 in the axial direction of the valve body 2 stops on the cavity wall of the accommodating chamber 402. The gasket 11 has a second through hole 1101 extending along the axial direction of the valve body 2. The gasket 11 is sleeved on the valve stem 7 through the second through hole 1101 and is arranged between the sleeve 10 and the pressure-regulating spring 9. The two ends of the gasket 11 in the axial direction of the valve body 2 respectively stop on the sleeve 10 and the pressure-regulating spring 9 to facilitate the installation of the pressure-regulating spring 9.

[0043] In some embodiments, the follow-up relief valve 100 of the embodiment of the present application also includes a connector 12, which is arranged on the valve body 2 and is used to connect to the diaphragm compressor 200. The connector 12 has an oil passage 1201, a channel inlet and a channel outlet, and the channel inlet is connected to the oil inlet 202.

[0044] For example, Figure 3 As shown, the connector 12 is connected to the valve body 2 by threads, and the connector 12 is also provided with a joint nut and a joint nut for connecting to the diaphragm compressor 200. The hydraulic oil in the oil-side membrane chamber 21 enters the oil channel 1201 through the channel inlet, and the hydraulic oil entering the oil channel 1201 flows to the oil inlet 202 through the oil channel 1201 outlet.

[0045] In some embodiments, the follow-up relief valve 100 of the embodiment of the present application also includes a connecting block 13, which is connected to the valve stem 7. The connecting block 13 has a groove 1301 with an opening toward the oil inlet 202. The valve core 8 is a sphere, and a part of the valve core 8 is placed in the groove 1301 and connected to the connecting block 13. For example, the valve core 8 is welded in the groove 1301 to achieve positioning of the valve core 8, so as to facilitate the installation of the valve core 8 and the valve stem 7.

[0046] In some embodiments, the servo control system 300 of the embodiment of the present application also includes a gas tank 16, for example, the gas pipe is a nitrogen tank 16, the electric proportional valve 15 includes a controller 1501, a gas inlet 1502 and a gas outlet 1503, the controller 1501 is connected to the pressure transmitter 14 to receive the electrical signal output by the pressure transmitter 14, the gas inlet 1502 is connected to the gas tank 16, and the gas outlet 1503 is connected to the air inlet 101 of the servo overflow valve 100.

[0047] After the electrical proportional valve 15 collects the electrical signal of the exhaust pressure, the controller 1501 can output an ideal voltage value to the electrical proportional valve 15. The electrical proportional valve 15 introduces the low-pressure gas in the gas tank 16 through the gas inlet 1502. The electrical proportional valve 15 controls the displacement of its own proportional electromagnet according to the voltage value given by the controller 1501 to automatically set the outlet pressure of its gas outlet 1503, thereby realizing the oil-gas pressure difference stabilization function. Due to the different modes of action of the air pressure acting on the self-actuated relief valve 100, before the diaphragm compressor 200 works, the follow-up relief valve 15 can realize the automatic bypass function of the follow-up relief valve 100 through the setting of the controller 1501 of the electrical proportional valve 15.

[0048] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0050] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0052] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0053] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present application. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present application.

Claims

1. A follow-up control system, characterized in that: The servo control system includes a servo overflow valve, and the servo overflow valve includes: A valve cover (1) and a valve body (2), wherein the valve cover (1) is threadedly connected to the valve body (2), the valve cover (1) is provided with an air inlet (101), and the valve body (2) is provided with an oil overflow chamber (201), an oil inlet (202), and an oil overflow port (203); A gas piston (3) and an oil piston (4), wherein the gas piston (3) is movably arranged in the valve cover (1) along the axial direction of the valve body (2), at least a portion of the oil piston (4) is arranged in the oil overflow chamber (201) and is movable along the axial direction of the valve body (2), a low-pressure chamber (5) is defined between the gas piston (3) and the valve cover (1), a high-pressure chamber (6) is defined between the gas piston (3), the valve cover (1) and the oil piston (4), the gas inlet (101) is communicated with the high-pressure chamber (6), the valve cover (1) has a first stop portion (102) located between the gas piston (3) and the oil piston (4), the oil piston (4) stops on the first stop portion (102), and the oil piston (4) has a first through hole (401) extending along the axial direction of the valve body (2); a valve stem (7) and a valve core (8), wherein the first end (701) of the valve stem (7) passes through the first through hole (401) and is connected to the gas piston (3), the second end (702) of the valve stem (7) is placed in the oil overflow chamber (201) and is connected to the valve core (8), the valve core (8) is used to block the oil inlet (202), and the valve stem (7) has a second stop portion; A pressure regulating spring (9), the pressure regulating spring (9) being sleeved on the valve stem (7) and having two ends of the pressure regulating spring (9) respectively abutting against the oil piston (4) and the second abutting portion; The servo control system further comprises a pressure transmitter (14) and an electrical proportional valve (15); the pressure transmitter (14) is used to be connected to the diaphragm compressor (200) to receive the exhaust pressure of the diaphragm compressor (200) and convert the exhaust pressure into an electrical signal; the electrical proportional valve (15) is connected to the pressure transmitter (14) to receive the electrical signal; the electrical proportional valve (15) is connected to the servo relief valve (100) to deliver compressed gas to the high-pressure chamber (6) of the servo relief valve (100); the pressure value of the compressed gas is inversely proportional to the value of the received electrical signal; When the exhaust pressure of the diaphragm compressor (200) increases, the electrical signal transmitted by the pressure transmitter (14) to the electrical proportional valve (15) increases, the pressure of the compressed gas transmitted by the electrical proportional valve (15) to the high-pressure chamber (6) decreases, the resultant force applied to the valve stem (7) increases, and the oil overflow pressure of the oil-side diaphragm chamber (21) of the diaphragm compressor (200) increases; conversely, when the exhaust pressure of the diaphragm compressor (200) decreases, the electrical signal transmitted by the pressure transmitter (14) to the electrical proportional valve (15) decreases, the pressure of the compressed gas transmitted by the electrical proportional valve (15) to the high-pressure chamber (6) increases, the resultant force applied to the valve stem (7) decreases, and the oil overflow pressure of the oil-side diaphragm chamber (21) of the diaphragm compressor (200) decreases.

2. The servo control system according to claim 1, characterized in that: The valve cover (1) has a vent hole (103) in communication with the low-pressure chamber (5), and the vent hole (103) is used to communicate with the atmospheric environment.

3. The follow-up control system according to claim 2, characterized in that: The oil piston (4) has a receiving chamber (402) and a first opening (403), wherein the first opening (403) is arranged in the axial direction of the valve body (2) toward the valve core (8), and at least a portion of the pressure regulating spring (9) is arranged in the receiving chamber (402).

4. The follow-up control system according to claim 3, characterized in that: The follow-up relief valve also includes: a bushing (10), the bushing (10) being located in the accommodating cavity (402) and sleeved on the valve stem (7), the end of the bushing (10) away from the valve core (8) in the axial direction of the valve body (2) abutting against the cavity wall of the accommodating cavity (402); and A cushion block (11), the cushion block (11) having a second through hole (1101) extending along the axial direction of the valve body (2), the cushion block (11) being sleeved on the valve stem (7) through the second through hole (1101) and being arranged between the bushing (10) and the pressure regulating spring (9), the two ends of the cushion block (11) in the axial direction of the valve body (2) respectively abutting against the bushing (10) and the pressure regulating spring (9).

5. The servo control system according to claim 4, characterized in that: The follow-up relief valve further comprises a connector (12), the connector (12) being arranged on the valve body (2) and used for connecting to the diaphragm compressor (200), the connector (12) having an oil passage (1201), a passage inlet and a passage outlet, the passage inlet being in communication with the oil inlet (202).

6. The servo control system according to claim 4, characterized in that: The follow-up relief valve further comprises a connecting block (13), the connecting block (13) being connected to the valve stem (7), the connecting block (13) having a groove (1301) opening toward the oil inlet (202), the valve core (8) being a sphere, a portion of the valve core (8) being disposed in the groove (1301) and connected to the connecting block (13).

7. The servo control system according to claim 1, characterized in that: It also includes a gas tank (16), and the electrical proportional valve (15) includes a controller (1501), a gas inlet (1502) and a gas outlet (1503). The controller (1501) is connected to the pressure transmitter (14) to receive the electrical signal output by the pressure transmitter (14), the gas inlet (1502) is connected to the gas tank (16), and the gas outlet (1503) is connected to the gas inlet (101) of the follow-up relief valve (100).

8. A diaphragm compressor system, characterized in that: include: Diaphragm compressors; A servo control system, wherein the servo control system is the servo control system according to any one of claims 1 to 7.

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