A pilot proportional valve for high-precision proportional control

Abstract

The application provides a high-precision proportional control pilot proportional valve, a pressure sensor detects the pressure of a gas outlet, and transmits the pressure value of the gas outlet to a control circuit board; the control circuit board transmits signals to a piezoelectric valve, controls the outlet pressure of the piezoelectric valve, and the part of the gas pressure controls the downward movement of an upper sealing diaphragm, a valve core movement assembly and the valve core against the resistance of a spring, so that a gas inlet flow channel and a gas outlet flow channel b are communicated, and the cross-sectional area of the gas flow is adjusted by adjusting the distance between the valve core and a lower sealing copper core, thereby realizing the adjustment of the outlet pressure; the required pilot gas of the piezoelectric valve is supplied after being regulated by a pressure regulating device through the gas inlet flow channel. The piezoelectric valve is used for pilot control, the proportional valve is designed as a proportional pilot example, the movement of the valve core is controlled by the pilot gas, the outlet pressure changes fast and has high precision; the complexity of the external pipeline is reduced, the valve body volume is reduced, and the power is significantly smaller than the power of a driving proportional electromagnet.

Description

Technical Field

[0001] This invention relates to the field of pilot proportional valve technology, specifically to a high-precision proportional control pilot proportional valve. Background Technology

[0002] Proportional valves are crucial components in electrical control systems, continuously controlling the speed, position, and output force of pneumatic actuators. In existing technologies, proportional valves are typically driven by proportional electromagnets. The movement of the electromagnet valve core allows for continuous and proportional remote control of fluid pressure, flow rate, or direction based on input electrical signals.

[0003] Currently, most proportional valve core seals use elastic polymer materials such as rubber or polyurethane. To achieve a good sealing effect with these highly elastic materials, a larger load is often required on the sealing components. This results in a larger spring force and a corresponding increase in the thrust of the proportional electromagnet, leading to a larger valve body size and requiring higher power from the circuit to drive the proportional electromagnet. This can be limiting in high-precision or outdoor applications due to power supply constraints. Furthermore, under closed-loop control, the proportional electromagnet needs to repeatedly collect outlet pressure data for adjustment. Since the electromagnet's adjustment speed lags behind the power supply, the repeated adjustments take a considerable amount of time. Summary of the Invention

[0004] To address the problems of existing proportional valves driven by electromagnets, this invention provides a high-precision proportional control pilot proportional valve. By using a piezoelectric valve for pilot control, the proportional valve is designed as a proportional pilot valve. The valve core movement is controlled by pilot air, resulting in rapid and accurate outlet pressure changes. This reduces the complexity of the external piping, decreases the valve body size, and significantly reduces the power required to drive the proportional electromagnet.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a pilot proportional valve for high-precision proportional control, including a control circuit board, a piezoelectric valve, a pressure sensor, a valve core motion assembly, an inner valve body, and a pressure regulating device integrated in the valve body housing;

[0006] The control circuit board is connected to the piezoelectric valve and the pressure sensor respectively. The piezoelectric valve's outlet is connected to the valve core movement assembly, which pushes the valve core movement assembly downward to contact and seal with the valve core in the central cavity of the inner valve body. The bottom of the valve core movement assembly is provided with an upper cavity spring, which allows the valve core movement assembly to move upward under elastic action and separate from the valve core. The pressure sensor is connected to the outlet flow channel b on the inner valve body, which detects and transmits the outlet pressure signal to the control circuit board.

[0007] The pressure regulating device is located below the valve core and is connected to the air inlet channel and the pilot airflow channel a on the inner valve body respectively. The pilot airflow channel a is connected to the piezoelectric valve inlet. The pilot air required by the piezoelectric valve is supplied by the pilot airflow channel a after being regulated by the pressure regulating device through the air inlet channel. The inner wall of the cavity where the valve core is located is provided with a lower sealing copper core located between the air inlet channel and the air outlet channel b. A lower chamber spring is provided at the bottom of the valve core. The valve core compresses the lower chamber spring downward to separate it from the lower sealing copper core, or it contacts the lower sealing copper core upward to seal under the elastic action of the lower chamber spring.

[0008] Furthermore, the valve body housing includes a lower valve body housing and an upper valve body housing. The inner valve body and pressure regulating device are located inside the lower valve body housing, while the control circuit board, piezoelectric valve, and pressure sensor are located inside the upper valve body housing. A transition valve body is provided between the lower valve body housing and the upper valve body housing, and a diaphragm fixing member is provided between the transition valve body and the inner valve body. The valve core moving assembly is slidably located in the internal cavity of the diaphragm fixing member.

[0009] Furthermore, the valve core moving assembly includes an upper sealing copper core, a diaphragm mounting bracket, and a middle sealing diaphragm; the bottom of the diaphragm mounting bracket is fixedly connected to the top of the upper sealing copper core as a whole, and the inner end of the middle sealing diaphragm is fixedly sealed between the diaphragm mounting bracket and the upper sealing copper core; an upper guide ring is provided on the inner wall of the top of the inner valve body cavity, the upper sealing copper core is slidably connected to the inner cavity of the upper guide ring, the bottom of the upper sealing copper core is connected to the top of the upper cavity spring, and the bottom end of the upper cavity spring is fixedly connected to the top of the lower sealing copper core; the diaphragm mounting bracket is slidably connected to the inner cavity of the diaphragm fixing component.

[0010] Furthermore, an upper sealing diaphragm is provided between the top of the diaphragm mounting bracket and the bottom of the transition valve body, and a piezoelectric valve outlet air passage is provided on the transition valve body, which connects the piezoelectric valve outlet and the upper sealing diaphragm.

[0011] Furthermore, a lower guide ring is provided on the inner wall of the bottom of the inner valve body cavity, and the lower part of the valve core is slidably disposed in the middle cavity of the lower guide ring. A pilot airflow channel d communicating with the inner valve body cavity is opened on the lower guide ring. The bottom of the valve core is connected to the top of the lower cavity spring, and the bottom of the lower cavity spring is connected to the rubber seat. A metal pin is connected to the bottom of the rubber seat, and a lower sealing diaphragm is provided at the bottom of the metal pin. A partition is sleeved on the outer wall of the metal pin, located between the bottom of the inner valve body and the lower sealing diaphragm. There are gaps between the partition and the outer wall of the metal pin, the top of the lower sealing diaphragm, and the bottom of the rubber seat. A vent hole is opened on the partition, and the vent hole connects the pilot airflow channel a with the above-mentioned gaps. The metal pin, the rubber seat, and the partition constitute a pressure regulating device for adjusting the pilot air pressure, which is used to reduce the pressure of the pilot air supplied to the piezoelectric valve.

[0012] Furthermore, the diaphragm fixing member is provided with a pilot airflow channel b and an air outlet channel b, and the transition valve body is also provided with a pilot airflow channel c and an air outlet channel c; the pilot airflow channel b is connected between the pilot airflow channel c and the pilot airflow channel a, and the pilot airflow channel c is connected to the air inlet of the piezoelectric valve; the air outlet channel b is connected between the air outlet channel c and the air outlet channel b, and the air outlet channel c is connected to the air inlet detection port of the pressure sensor.

[0013] Furthermore, the side of the partition plate is connected to the side of the sealing diaphragm; a sealing plug is provided in the bottom cavity of the lower valve body housing, the top of the sealing plug is connected to the bottom of the lower sealing diaphragm, the bottom of the sealing plug is connected to an elastic partition plate, the bottom of the elastic partition plate is connected to an adjusting screw, and the adjusting screw is embedded in the lower valve body housing.

[0014] The beneficial effects of this invention include: by using a piezoelectric valve for pilot control, the proportional valve is designed as a proportional pilot valve, utilizing pilot gas to control the movement of the valve core. The piezoelectric valve offers advantages such as extremely low energy consumption, rapid response, and long service life. The position of the proportional valve core changes with the pilot gas pressure, resulting in rapid and accurate outlet pressure changes. The pilot gas used in this invention is depressurized by an internal pressure regulating device before being supplied to the piezoelectric valve, ensuring its normal operation, reducing the complexity of external piping, and decreasing the valve body size. The gas pressure driving the valve core movement originates from the inlet pressure, and its power is significantly less than that driving the proportional electromagnet. High-precision metal sealing is employed, resulting in smaller components and faster response times for achieving the same sealing performance. In summary, the pilot-operated proportional valve of this invention offers advantages such as high accuracy, rapid response, low power consumption, low gas consumption, small size, long service life, and compact structure. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view of the overall structure of a pilot proportional valve for high-precision proportional control according to the present invention.

[0016] Figure 2 This is a diagram showing the positions of various components of a high-precision proportional control pilot proportional valve during operation; the arrows indicate the gas flow paths after intake and pressure regulation.

[0017] Figure 3 This is a diagram showing the positions of various components during exhaust of a high-precision proportional control pilot proportional valve according to the present invention; the arrows indicate the gas flow path during exhaust at the outlet.

[0018] Figure 4 This is a pilot airflow diagram for a high-precision proportional control pilot proportional valve of the present invention; the arrows indicate the flow path of the pilot air.

[0019] The following are the labeling symbols in the attached diagram: 1. Adjusting screw; 2. Elastic diaphragm; 3. Sealing plug; 4. Lower valve body shell; 5. Lower sealing diaphragm; 6. Sealing ring a; 7. Filter gasket; 8. Inner valve body; 8.1. Pilot airflow channel a; 8.2. Outlet airflow channel b; 8.3. Inlet airflow channel; 9. Diaphragm fixing component; 9.1. Pilot airflow channel b; 9.2. Outlet airflow channel b; 10. Transition valve body; 10.1. Pilot airflow channel c; 10.2. Piezoelectric valve outlet airflow channel; 10.3. Outlet airflow channel c; 11. Piezoelectric valve; 11.1. Piezoelectric valve inlet; 11.2. Piezoelectric valve outlet. 12. Air inlet, 13. Upper valve body housing, 14. Control circuit board, 15. Connector, 16. Pressure sensor, 17.1. Air inlet detection port, 18. Upper sealing diaphragm, 19. Diaphragm mounting bracket, 20. Middle sealing diaphragm, 21. Upper guide ring, 22. Upper cavity spring, 21. Lower sealing copper core, 21.1. Lower sealing chamfer, 22. Valve core, 23. Lower guide ring, 23.1. Pilot airflow channel d, 24. Lower cavity spring, 25. Sealing ring b, 26. Metal pin, 27. Upper sealing copper core, 27.1. Upper sealing chamfer, 28. Sealing ring c, 29. Rubber seat, 30. Spacer. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used only to distinguish components and should not be construed as indicating or implying relative importance.

[0022] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] A high-precision proportional control pilot proportional valve is disclosed. Valve control is achieved by an external signal transmitted to a control circuit board 13. A pressure sensor 15 detects the outlet pressure and transmits the pressure value to the control circuit board 13. The control circuit board 13 then transmits the signal to a piezoelectric valve 11, controlling its outlet pressure. This gas pressure controls the upper sealing diaphragm 16, the valve core moving assembly, and the valve core 22 to move downwards against the spring resistance, connecting the inlet flow channel 8.3 and the outlet flow channel b8.2. The cross-sectional area of ​​gas flow is adjusted by regulating the distance between the valve core 22 and the lower sealing copper core 21, thereby regulating the outlet pressure. The pilot gas required by the piezoelectric valve 11 is supplied from the inlet flow channel 8.3 after pressure regulation by a pressure regulating device.

[0024] Example 1

[0025] The specific structure of a high-precision proportional control pilot proportional valve is as follows: it is provided with a lower valve body shell 4 and an upper valve body shell 12. An inner valve body 8 and a pressure regulating device are provided inside the lower valve body shell 4. A control circuit board 13, a piezoelectric valve 11, and a pressure sensor 15 are provided inside the upper valve body shell 12. A transition valve body 10 is provided between the lower valve body shell 4 and the upper valve body shell 12. A diaphragm fixing member 9 is provided between the transition valve body 10 and the inner valve body 8. A valve core moving assembly that can move vertically is provided in the internal cavity of the diaphragm fixing member 9.

[0026] The inner valve body 8 is provided with a pilot airflow channel a8.1, an outlet channel b8.2, and an inlet channel 8.3. A vertically movable valve core 22 is provided in the middle cavity. One opening of the inlet channel 8.3 is connected to the atmosphere, and the other opening is connected to the cavity where the valve core 22 is located. The first opening of the outlet channel b8.2 is connected to the atmosphere, the second opening is connected to the cavity where the valve core 22 is located, and the third opening is connected upward to the outlet channel b9.2 opened on the diaphragm fixing member 9.

[0027] The valve core 22 has outwardly expanding spherical surfaces at the top and bottom. The inner wall of the cavity where the valve core 22 is located is provided with a lower sealing copper core 21. The lower sealing copper core 21 and the lower spherical surface of the valve core 22 constitute the valve's opening and closing mechanism. The contact position between the two is the lower sealing chamfer 21.1, forming a metal seal, which has the advantages of low sealing pressure and fast response speed.

[0028] The inner wall of the cavity where the valve core 22 is located is also provided with a lower guide ring 23. The lower part of the valve core 22 is slidably located in the middle cavity of the lower guide ring 23. A pilot airflow channel d23.1 communicating with the cavity where the valve core 22 is located is opened on the lower guide ring 23.

[0029] The bottom of the valve core 22 is connected to the top of the lower cavity spring 24, and the bottom of the lower cavity spring 24 is connected to the rubber seat 29; the bottom of the rubber seat 29 is connected to the metal pin 26, and the bottom of the metal pin 26 is provided with a lower sealing diaphragm 5; a partition 30 is sleeved on the outer wall of the metal pin 26.

[0030] A gap a is provided between the partition 30 and the outer wall of the metal pin 26; the partition 30 is disposed in the cavity formed between the bottom of the inner valve body 8 and the lower sealing diaphragm 5, and the side of the partition 30 is connected to the side of the sealing diaphragm 5; a gap b is provided between the bottom of the partition 30 and the lower sealing diaphragm 5, and a gap c is provided between the partition 30 and the bottom of the rubber seat 29; Reference Figure 4 The fluid arrow points to the pilot airflow channel d23.1, gap c, gap a, and gap b being connected in sequence;

[0031] A vent hole is provided on the partition 30, which connects the bottom first channel opening of the pilot airflow channel a8.1 with the aforementioned gap b; preferably, a filter pad 7 is provided at the bottom first channel opening of the pilot airflow channel a8.1; gas enters the lower cavity of the valve core 22 from the air inlet channel 8.3, flows through the pilot airflow channel d23.1, and then passes through the gap c between the bottom of the rubber seat 29 and the partition 30, the gap a between the metal pin 26 and the partition 30, and flows into the gap b between the bottom of the partition 30 and the lower sealing diaphragm 5. After passing through the vent hole on the partition 30 and being filtered by the filter pad 7, it flows into the pilot airflow channel a8.1;

[0032] A sealing ring a6 and a sealing ring b25 are respectively provided between the partition 30 and the inner valve body 8; wherein the sealing ring b25 is used to seal the gap c between the bottom of the rubber seat 29 and the partition 30, and the sealing ring a6 is used to seal the first channel opening at the bottom of the pilot airflow channel a8.1 and the vent hole on the partition 30.

[0033] The aforementioned metal pin 26, rubber seat 29, and partition 30 constitute a pressure regulating device that can adjust the pilot gas switch and pressure, and is used to reduce the pressure of the pilot gas supplied to the piezoelectric valve 11.

[0034] Specifically, a sealing plug 3 is provided in the bottom cavity of the lower valve body housing 4. The top of the sealing plug 3 is connected to the bottom of the lower sealing diaphragm 5, and the bottom of the sealing plug 3 is connected to an elastic partition 2. The bottom of the elastic partition 2 is connected to an adjusting screw 1, which is embedded in the lower valve body housing 4. When the adjusting screw 1 is turned, the sealing plug 3 drives the lower sealing diaphragm 5. Since the side of the partition 30 is connected to the side of the sealing diaphragm 5, the partition 30 is driven to control its height. The height of the partition 30 controls the distance between the bottom of the rubber seat 29 and the partition 30, thereby controlling the pilot gas pressure.

[0035] The diaphragm fixing member 9 is provided with a pilot airflow channel b9.1 and an air outlet channel b9.2 respectively. The bottom port of the pilot airflow channel b9.1 is connected to the second channel opening at the top of the pilot airflow channel a8.1, and the bottom port of the air outlet channel b9.2 is connected to the third channel opening of the air outlet channel b8.2.

[0036] The valve core moving assembly includes an upper sealing copper core 27, a diaphragm mounting bracket 17, and a middle sealing diaphragm 18; the bottom of the diaphragm mounting bracket 17 is fixedly connected to the top of the upper sealing copper core 27 as a whole, the inner end of the middle sealing diaphragm 18 is fixedly sealed between the diaphragm mounting bracket 17 and the upper sealing copper core 27, and the outer ring of the middle sealing diaphragm 18 is fixed between the inner valve body 8 and the diaphragm fixing member 9; a sealing ring c28 is provided between the middle sealing diaphragm 18 and the inner valve body 8;

[0037] An upper guide ring 19 is provided on the inner wall of the top of the cavity of the inner valve body 8. The upper sealing copper core 27 is slidably connected in the inner cavity of the upper guide ring 19. The bottom of the upper sealing copper core 27 is connected to the top of the upper cavity spring 20. The bottom of the upper cavity spring 20 is fixedly connected to the top of the lower sealing copper core 21. The diaphragm mounting bracket 17 is slidably connected in the inner cavity of the diaphragm fixing member 9. The upper sealing copper core 27 and the upper spherical surface of the valve core 22 form the exhaust seal after the valve is opened. The contact position between the two is the upper sealing chamfer 27.1, which forms a metal seal with the advantages of low sealing pressure and fast response speed.

[0038] An upper sealing diaphragm 16 is provided between the top of the diaphragm mounting bracket 17 and the bottom of the transition valve body 10, and the outer end of the upper sealing diaphragm 16 is fixed between the diaphragm fixing member 9 and the transition valve body 10.

[0039] The transition valve body 10 is provided with a pilot airflow channel c10.1, a piezoelectric valve outlet airflow channel 10.2, and an outlet airflow channel c10.3. The bottom end of the pilot airflow channel c10.1 is connected to the top end of the pilot airflow channel b9.1, and the top end is connected to the piezoelectric valve inlet 11.1 of the piezoelectric valve 11. The top end of the piezoelectric valve outlet airflow channel 10.2 is connected to the piezoelectric valve outlet 11.2 of the piezoelectric valve 11, and the bottom end enters the upper cavity of the upper sealing diaphragm 16, driving the diaphragm mounting bracket 17 and the upper sealing copper core 27 to push the valve core 22 downward. The upper sealing diaphragm 16 separates the pilot cavity and the valve cavity, and can move up and down through the arc structure. The bottom end of the outlet airflow channel c10.3 is connected to the top end of the outlet channel b9.2, and the top end is connected to the inlet detection port 15.1 of the pressure sensor 15.

[0040] The control circuit board 13 is connected to the piezoelectric valve 11 and the pressure sensor 15 respectively. The upper valve body housing 12 is provided with a connector 14 connected to the control circuit board 13. The connector 14 is connected to DC power and control signals.

[0041] Based on the above implementation scheme, the pressure in the inlet channel 8.3 is reduced and regulated by the bottom pressure regulating device before being supplied to the piezoelectric valve 11. After the external control signal is transmitted to the control circuit board 13, the control circuit board 13 adjusts the outlet pressure of the piezoelectric valve 11. This gas pushes the valve core moving assembly to overcome the resistance of the upper chamber spring 20 and open. At the same time, the control circuit board 13 detects the outlet pressure signal through the pressure sensor 15 and performs closed-loop control, transmitting the signal to the piezoelectric valve 11. The opening position of the valve core moving assembly is controlled by controlling the outlet pressure of the piezoelectric valve 11.

[0042] The valve is sealed with a metal-to-metal contact seal. The valve core 22 and the lower sealing copper core 21 constitute the valve's opening and closing mechanism. The valve core 22 and the upper sealing copper core 27 constitute the exhaust seal after opening. The metal seal has the advantages of low sealing pressure and fast response speed.

[0043] The pilot gas required by the piezoelectric valve 11 is supplied after being diverted and depressurized by the valve's inlet air path: the gas enters the lower cavity of the valve core 22 through the inlet channel 8.3, flows through the pilot air channel d23.1, and then flows into the bottom of the partition 30 through the gap between the rubber seat 29 and the metal pin 26 and the partition 30. After passing through the vent hole on the partition 30 and being filtered by the filter pad 7, it sequentially flows through the pilot air channel a8.1, pilot air channel b9.1, and pilot air channel c10.1 and enters the piezoelectric valve inlet 11.1. Among them, the metal pin 26, the rubber seat 29, and the partition 30 constitute a pressure regulating device that can adjust the pilot gas switch and pressure. The height of the partition 30 is controlled by adjusting the set screw 1, and the height of the partition 30 controls the distance between the bottom of the rubber seat 29 and the partition 30, thereby realizing the control of the pilot gas pressure.

[0044] The actuator driven by the pilot section employs an upper sealing diaphragm 16 and a middle sealing diaphragm 18. Gas enters the upper cavity of the upper sealing diaphragm 16 from the piezoelectric valve outlet 11.2, driving the diaphragm mounting bracket 17 and the upper sealing copper core 27. The diaphragm mounting bracket 17 and the upper sealing copper core 27 secure and seal the middle sealing diaphragm 18, and push the valve core 22 downward. The upper sealing diaphragm 16 separates the pilot cavity and the valve cavity, and its intermediate arc-shaped structure allows for vertical movement.

[0045] Applying the piezoelectric valve 11 to the control of the proportional valve results in extremely low overall power consumption of the valve, making it particularly suitable for outdoor and low-energy-consumption equipment.

[0046] like Figure 1 As shown, Figure 1This is a structural diagram of a pilot proportional valve for high-precision proportional control. The inner valve body 8 includes a pilot airflow channel a8.1, an outlet channel b8.2, and an inlet channel 8.3. The inner valve body 8 is installed at the bottom of the lower valve body housing 4. Pilot air is depressurized by the bottom pressure regulating device and supplied to the piezoelectric valve 11 through the pilot airflow channel. The operation of the piezoelectric valve 11 is controlled by the control circuit board 13. The connector 14 is connected to external DC power and control signals. The outlet 11.2 of the piezoelectric valve drives the valve core moving assembly to move downward, executing the valve opening action. The pressure sensor 15 detects the gas pressure at the outlet. In the diagram, the lower sealing diaphragm 5, the upper sealing diaphragm 16, and the middle sealing diaphragm 18 are all designed with a curved middle section, allowing for a certain amount of movement while also providing a sealing function.

[0047] like Figure 2 As shown, Figure 2 This describes the positions of various components in a high-precision proportional control pilot proportional valve during operation. The upper sealing copper core 27 and the diaphragm mounting bracket 17 are fixed together, securing the middle sealing diaphragm 18 in the middle. These three components constitute the valve core movement assembly. The middle sealing diaphragm 18 isolates the upper and lower chambers. The upper sealing diaphragm 16 is mounted on the valve core movement assembly. The upper spherical part of the valve core 22 forms a metal seal with the upper sealing chamfer 27.1 of the upper sealing copper core 27. The upper guide ring 19 guides the upper sealing copper core 27. The lower spherical surface of the valve core 22 forms a metal seal with the lower sealing chamfer 21.1 of the lower sealing copper core 21. When the valve is not open, under the elastic force of the lower chamber spring 24, the lower spherical surface of the valve core 22 contacts the lower sealing chamfer 21.1 and forms a seal, while the upper seal is separated under the action of the upper chamber spring 20. The upper sealing ring c28 isolates the lower outlet chamber from the upper control chamber. When the pressure regulating signal is sent to the control circuit board 13, the control circuit board 13 controls the piezoelectric valve 11 to open. After the piezoelectric valve outlet 11.2 is pressurized, it drives the valve core moving assembly to move downward. At this time, the upper spherical part of the valve core 22 and the upper sealing chamfer 27.1 of the upper sealing copper core 27 form a metal seal and are in a sealed state. The lower spherical part of the valve core 22 and the lower sealing chamfer 21.1 of the lower sealing copper core 21 are in an open state. The inlet flow channel 8.3 and the outlet flow channel b8.2 are connected. At this time, the pressure sensor 15 collects the air pressure of the outlet flow channel b8.2 and transmits the signal to the control circuit board 13 for calculation with the input signal. If the air pressure value of the outlet flow channel b8.2 is less than the input signal, the outlet pressure of the piezoelectric valve 11 is increased, and the valve core moving assembly is controlled to continue to move downward, increasing the flow cross-sectional area, thereby increasing the outlet air pressure until the two values ​​are equal. If the air pressure value of the outlet flow channel b8.2 is greater than the input signal, the outlet pressure of the piezoelectric valve 11 is reduced to control the valve core moving assembly to move upward, reduce the flow cross-sectional area, and thus reduce the outlet air pressure until the two values ​​are equal. Figure 2 The arrow shown indicates the direction of gas flow when the circuit is open.

[0048] Figure 3 This is a diagram showing the positions of various components during exhaust of a pilot proportional valve used for high-precision proportional control. When the actuator connected to the outlet flow channel b8.2 experiences high pressure and requires exhaust, the signal detected by the pressure sensor 15 is transmitted to the control circuit board 13. The control circuit board 13 closes the piezoelectric valve 11. At this time, the valve core moving assembly moves upward under the elastic force of the upper chamber spring 20. The upper spherical part of the valve core 22 and the upper sealing chamfer 27.1 of the upper sealing copper core 27 are in an open state, while the lower spherical part of the valve core 22 and the lower sealing chamfer 21.1 of the lower sealing copper core 21 form a metal seal, creating a sealed state. The gas at the outlet flow channel b8.2 is discharged into the atmosphere through the upper cavity via the open upper sealing chamfer 27.1, thus completing the exhaust process. Figure 3 The arrows shown indicate the direction of gas flow during exhaust. The upper cavity is formed by the following sequentially connected components: the central cavity of the upper sealing copper core 27, the transverse channel on the diaphragm mounting bracket 17, the transverse channel on the diaphragm fixing member 9, and the transverse channel formed between the lower valve body shell 4 and the transition valve body 10.

[0049] Figure 4 This is a pilot air flow diagram for a high-precision proportional control pilot proportional valve. The piezoelectric valve 11 uses a lower gas pressure, while the main circuit pressure controlled by the proportional valve is higher. To enable the proportional valve to have a wider range of pressure applications, the pilot air required by the piezoelectric valve 11 needs to be reduced in pressure before supplying it. The metal pin 26 passes through the partition 30 and connects to the rubber seat 29. A certain gap is maintained between the metal pin 26 and the partition 30 to allow the pilot air to pass through. The bottom of the rubber seat 29 is designed with a spherical protrusion, allowing gas to flow in through the gap. The height of the partition 30 is controlled by adjusting the set screw 1. The height of the partition 30 controls the distance between the bottom of the rubber seat 29 and the partition 30, thereby controlling the pilot air pressure. The main gas enters the lower cavity of valve core 22 through inlet channel 8.3, flows through pilot airflow channel d23.1, and then flows into the bottom of partition 30 through the gap between the bottom of rubber seat 29 and metal pin 26 and partition 30. After passing through the vent holes on partition 30 and being filtered by filter pad 7, the gas flows through pilot airflow channels a8.1, b9.1, and c10.1 before entering the piezoelectric valve inlet 11.1. Figure 4 The arrow shown indicates the direction of pilot gas flow.

[0050] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A pilot proportional valve for high-precision proportional control, characterized in that, Includes a control circuit board (13) integrated in the valve body housing, a piezoelectric valve (11), a pressure sensor (15), a valve core motion assembly, an inner valve body (8), and a pressure regulating device; The control circuit board (13) is connected to the piezoelectric valve (11) and the pressure sensor (15) respectively. The piezoelectric valve outlet (11.2) of the piezoelectric valve (11) is connected to the valve core movement assembly to push the valve core movement assembly downward to contact and seal with the valve core (22) in the middle cavity of the inner valve body (8). The bottom of the valve core movement assembly is provided with an upper cavity spring (20) to make the valve core movement assembly move upward under elastic action and separate from the valve core (22). The pressure sensor (15) is connected to the outlet flow channel b (8.2) on the inner valve body (8) to detect and transmit the outlet pressure signal to the control circuit board (13). The pressure regulating device is located below the valve core (22) and is connected to the air inlet channel (8.3) and the pilot airflow channel a (8.1) on the inner valve body (8). The pilot airflow channel a (8.1) is connected to the piezoelectric valve inlet (11.1) of the piezoelectric valve (11). The pilot air required by the piezoelectric valve (11) is supplied by the pilot airflow channel a (8.1) after being regulated by the pressure regulating device through the air inlet channel (8.3). The inner wall of the cavity where the valve core (22) is located is provided with a lower sealing copper core (21) located between the air inlet channel (8.3) and the air outlet channel b. The bottom of the valve core (22) is provided with a lower chamber spring (24). The valve core (22) compresses the lower chamber spring (24) downward to separate it from the lower sealing copper core (21), or it contacts the lower sealing copper core (21) upward under the elastic action of the lower chamber spring (24) to seal.

2. The high-precision proportional control pilot proportional valve according to claim 1, characterized in that, The valve body housing includes a lower valve body housing (4) and an upper valve body housing (12). The inner valve body (8) and the pressure regulating device are located inside the lower valve body housing (4). The control circuit board (13), the piezoelectric valve (11), and the pressure sensor (15) are located inside the upper valve body housing (12). A transition valve body (10) is provided between the lower valve body housing (4) and the upper valve body housing (12). A diaphragm fixing member (9) is provided between the transition valve body (10) and the inner valve body (8). The valve core moving assembly is slidably located in the cavity inside the diaphragm fixing member (9).

3. The high-precision proportional control pilot proportional valve according to claim 2, characterized in that, The valve core moving assembly includes an upper sealing copper core (27), a diaphragm mounting bracket (17), and a middle sealing diaphragm (18). The bottom of the diaphragm mounting bracket (17) is fixedly connected to the top of the upper sealing copper core (27) as a whole, and the inner end of the middle sealing diaphragm (18) is fixedly sealed between the diaphragm mounting bracket (17) and the upper sealing copper core (27). An upper guide ring (19) is provided on the inner wall of the top of the cavity of the inner valve body (8). The upper sealing copper core (27) is slidably connected in the inner cavity of the upper guide ring (19). The bottom of the upper sealing copper core (27) is connected to the top of the upper cavity spring (20), and the bottom of the upper cavity spring (20) is fixedly connected to the top of the lower sealing copper core (21). The diaphragm mounting bracket (17) is slidably connected in the inner cavity of the diaphragm fixing component (9).

4. A pilot proportional valve for high-precision proportional control according to claim 3, characterized in that, An upper sealing diaphragm (16) is provided between the top of the diaphragm mounting bracket (17) and the bottom of the transition valve body (10). A piezoelectric valve outlet air passage (10.2) is provided on the transition valve body (10). The piezoelectric valve outlet air passage (10.2) is connected between the piezoelectric valve outlet (11.2) and the upper sealing diaphragm (16).

5. A pilot proportional valve for high-precision proportional control according to claim 4, characterized in that, The inner wall of the cavity of the inner valve body (8) is provided with a lower guide ring (23). The lower part of the valve core (22) is slidably disposed in the middle cavity of the lower guide ring (23). A pilot airflow channel d (23.1) communicating with the cavity of the inner valve body (8) is opened on the lower guide ring (23). The bottom of the valve core (22) is connected to the top of the lower cavity spring (24). The bottom of the lower cavity spring (24) is connected to the rubber seat (29). The bottom of the rubber seat (29) is connected to a metal pin (26). The bottom of the metal pin (26) is provided with a lower sealing diaphragm (5). A sleeve is provided on the outer wall of the metal pin (26). There is a partition (30) located between the bottom of the inner valve body (8) and the lower sealing diaphragm (5); the partition (30) has a gap that communicates with the outer wall of the metal pin (26), the top of the lower sealing diaphragm (5), and the bottom of the rubber seat (29); the partition (30) has a vent hole that connects the pilot airflow channel a (8.1) to the above gaps; the metal pin (26), the rubber seat (29), and the partition (30) constitute a pressure regulating device for adjusting the pilot air pressure, which is used to reduce the pressure of the pilot air supplied to the piezoelectric valve (11).

6. A pilot proportional valve for high-precision proportional control according to claim 5, characterized in that, The diaphragm fixing member (9) is provided with a pilot airflow channel b (9.1) and an outlet channel b (9.2), and the transition valve body (10) is provided with a pilot airflow channel c (10.1) and an outlet channel c (10.3). The pilot airflow channel b (9.1) is connected between the pilot airflow channel c (10.1) and the pilot airflow channel a (8.1), and the pilot airflow channel c (10.1) is connected to the piezoelectric valve inlet (11.1). The outlet channel b (9.2) is connected between the outlet channel c (10.3) and the outlet channel b (8.2), and the outlet channel c (10.3) is connected to the pressure sensor (15) inlet detection port (15.1).

7. A pilot proportional valve for high-precision proportional control according to claim 5, characterized in that, The side of the partition (30) is connected to the side of the sealing diaphragm (5); a sealing plug (3) is provided in the bottom cavity of the lower valve body shell (4), the top of the sealing plug (3) is connected to the bottom of the lower sealing diaphragm (5), the bottom of the sealing plug (3) is connected to the elastic partition (2), the bottom of the elastic partition (2) is connected to the adjusting screw (1), and the adjusting screw (1) is embedded in the lower valve body shell (4).

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