High-precision proportional valve

Abstract

The invention provides a high-precision proportional valve to at least solve the technical problem of precision in the prior art. The high-precision proportional valve comprises a valve body, a valve element, a valve cover, a leather membrane, a driving part and a hydraulic part, the valve element is installed on the valve body to control the flow of a valve body channel, an inner sealing part of the leather membrane is installed on the valve element, an outer sealing part of the leather membrane is installed on the valve body through the valve cover, and the hydraulic part is provided with an input end and an output end. The driving piece drives the input end to move, the output end drives the valve element to move, and the moving distance of the input end is larger than that of the output end. The moving distance of the input end is larger than the moving distance of the output end, the opening and closing stroke of the valve element within a certain current change range can be reduced, the resolution ratio is improved, and in other words, the opening degree change of the valve element when the driving piece moves at the input end by a unit distance is reduced; the proportional valve driven by the motor corresponds to the change of the opening degree of a pulse valve.

Description

Technical Field

[0001] This application relates to the field of valves, and more particularly to high-precision proportional valves. Background Technology

[0002] The proportional valve is a core component of a gas boiler, controlling the pressure and flow rate of the gas. Gas pressure affects combustion performance; incomplete combustion increases energy consumption and pollutes the air. Gas flow rate affects heat output, which frequently needs adjustment based on actual needs. This adjustment is accompanied by changes in flow rate. For example, the power output of gas-fired hot water is affected by temperature and water flow rate. Setting higher temperatures and larger water flows requires higher combustion power, but pressure changes with flow rate at different power levels. Traditional proportional valves, especially those with lower precision, struggle to control pressure when flow rate changes. In some cases, pressure sensors are used in conjunction with the proportional valve to ensure stable and controllable pressure, but this increases cost. Furthermore, unstable pressure can cause the valve core to vibrate, further exacerbating pressure instability and potentially leading to incomplete combustion or even deflagration. While servo proportional valves offer high-precision control, they are more expensive, while ordinary electromagnetically driven and stepper motor-controlled proportional valves have relatively lower precision.

[0003] Chinese patent application CN111288201A, entitled "A Motor-Motor Gas Proportional Valve," discloses a motor-motor gas proportional valve, comprising a proportional valve, a motor end cover, a stepper motor fixed to the top of the motor end cover, an installation channel on the motor end cover, the output shaft of the stepper motor located within the installation channel and threadedly connected to a transmission screw block, a transmission sleeve connected to the transmission screw block within the installation channel, and a flow regulator fixed to the bottom of the transmission sleeve extending out of the installation channel. The advantage of this application is that it simplifies the structure of the motor-motor proportional valve by using the cooperation of the transmission sleeve and the transmission screw block, ensuring the adjustment accuracy of the proportional valve. However, the structure is complex and the production cost is high. Summary of the Invention

[0004] This application provides a high-precision proportional valve to at least solve the precision technical problems existing in the prior art.

[0005] According to this application, a high-precision proportional valve is provided, including a valve body, a valve core, a valve cover, a diaphragm, a drive element, and a hydraulic unit. The valve core is installed in the valve body to control the flow rate of the valve body channel. The inner sealing part of the diaphragm is installed in the valve core, and the outer sealing part of the diaphragm is installed in the valve body through the valve cover. The hydraulic unit has an input end and an output end, with the cross-sectional area of ​​the output end being larger than that of the input end. The drive element drives the input end to move, and the output end drives the valve core to move. The moving distance of the input end is greater than the moving distance of the output end.

[0006] Compared to existing technologies, the high-precision proportional valve of this application has the following advantages: The input end travel distance is greater than the output end travel distance, which reduces the opening and closing stroke of the valve core within a certain current variation range, improving resolution. This means reducing the change in valve core opening when the driving component moves a unit distance at the input end. For an electromagnet-driven proportional valve, this corresponds to a unit current change; for a motor-driven proportional valve, it corresponds to a pulse change in valve opening. This results in higher control precision for the valve core. For proportional valves driven by electromagnets, the section with lower hysteresis can be selected as the working section, and the hydraulic unit amplifies the force to meet the driving requirements within the valve core's stroke range. The section with lower hysteresis also improves the control precision of the proportional valve during pressure fluctuations, making the internal pressure of the proportional valve more stable, the adjustment more sensitive, the gas combustion more complete, and the energy consumption lower, resulting in energy saving. Using a stepper motor as the driving component reduces the power of the stepper motor, enabling speed reduction transmission and lowering the cost of the proportional valve. It also increases precision and is less expensive than high-precision servo motors.

[0007] In one embodiment, the driving component is an electromagnet or a stepper motor. Compared to servo motors, electromagnets and stepper motors are less expensive, and with the amplification effect of the hydraulic unit, they can achieve the same high precision.

[0008] In one embodiment, the hydraulic unit has a stepped cavity, which includes a first cavity and a second cavity. The inner diameter of the first cavity is smaller than that of the second cavity. The first cavity has a first sealing element, and the second cavity has a second sealing element. Liquid is present in the stepped cavity so that when the first sealing element moves axially, the second sealing element moves axially simultaneously. By changing the ratio of the inner diameters of the first and second cavities, the driving force of the drive component can be proportionally amplified. For example, if the inner diameter of the first cavity is 1 mm and the inner diameter of the second cavity is 10 mm, a 100-fold amplification can be achieved. That is, if the drive component outputs a force of 1 Newton, the output end of the hydraulic unit can output a force of 100 Newtons, greatly increasing the driving force. For a stepper motor, if the drive component moves linearly by 100 mm, the output end of the hydraulic unit moves by 1 mm, greatly improving the accuracy of the movement and enabling the stepper motor to approach the accuracy of a servo motor.

[0009] In one embodiment, the hydraulic unit is provided with a stepped tube, which includes a first section and a second section. The diameter of the first section is smaller than that of the second section. A stepped cavity is formed inside the stepped tube, so that the first section forms a first cavity and the second section forms a second cavity. The first section and the second section are integrally formed, which can reduce production costs. That is, by using a deep drawing process to expand the hole, the pipe can be drawn into a stepped tube.

[0010] In one embodiment, a first sealing element is provided in the first pipe section, and a second sealing element is provided in the second pipe section. For a solenoid valve driven by an electromagnet, the first sealing element can be the iron core of the electromagnet, with a sealing ring installed on the iron core. For a proportional valve driven by a stepper motor, the first sealing element can be a common piston structure, driven by a transmission structure. The second sealing element can be a separate piston structure or a diaphragm can be used directly as the second sealing element.

[0011] In one embodiment, the first sealing member is driven by a driving member, and the second sealing member drives the valve core to move. The first sealing member is the input end of the hydraulic unit, and the second sealing member is the output end of the hydraulic unit. In some embodiments, the second sealing member and the valve core can be fixed together and move synchronously.

[0012] In one embodiment, the second sealing member is provided with an oil injection hole, which is eccentrically positioned relative to the second sealing member, and a plug is provided for the oil injection hole. The stepped pipe requires hydraulic oil to function properly. Since air is compressible, filling it with air will reduce the accuracy of the valve core's opening and closing. Providing an oil injection hole facilitates oil injection into the second sealing member; that is, the first and second sealing members are first moved to a certain position, then oil is injected until it overflows, and finally the oil injection hole is sealed with the plug.

[0013] In one embodiment, the hydraulic unit includes a straight pipe, which is sealed and installed on the valve cover. A first cavity is formed inside the straight pipe, and a second cavity is formed at the center of the valve cover. A first sealing element is provided in the first cavity, and the second cavity is sealed by a diaphragm. When the first sealing element moves, the diaphragm drives the valve core to move axially. This structure is simple, has fewer parts, lower manufacturing costs, and is easier to assemble.

[0014] In one embodiment, the diaphragm includes an outer sealing portion, an outer connecting portion, an inner folded portion, an outer folded portion, an inner connecting portion, and an inner sealing portion. The inner folded portion and the outer folded portion extend axially along the valve core. The outer sealing portion, outer connecting portion, outer folded portion, inner folded portion, inner connecting portion, and inner sealing portion are connected sequentially, and the outer diameters of the outer sealing portion, outer connecting portion, outer folded portion, inner folded portion, inner connecting portion, and inner sealing portion decrease sequentially, so that the outer sealing portion, outer connecting portion, outer folded portion, inner folded portion, inner connecting portion, and inner sealing portion are arranged radially. This allows the diaphragm to stably drive the valve core, and the shape change of the diaphragm is more stable, avoiding axial movement of the valve core caused by changes in the diaphragm shape, which would affect the control accuracy of the valve core and ensure a one-to-one correspondence between the displacement of the driving component and the displacement of the valve core.

[0015] In one embodiment, a tray is provided below the diaphragm, the outer diameter of the tray being smaller than the inner diameter of the upper hole of the valve body. An inner fold and an outer fold are located between the tray and the upper hole. The tray is fixed to the valve core. When the tray moves along a first direction, the inner fold at least partially flips outward to a position flush with the outer fold. The tray provides good support for the diaphragm, ensuring its flatness. In one embodiment, a return spring is provided between the diaphragm and the first sealing element. When the first sealing element approaches the diaphragm, it compresses the return spring. When the pressure in the valve body cavity drops rapidly, the return spring pushes the valve core to move in a first direction, increasing the opening of the proportional valve. This allows for a faster response to pressure changes and reduces reliance on electronic control. It has both proportional amplification and pressure stabilization functions. A larger proportional valve opening indicates a larger required flow rate, resulting in higher outlet pressure, greater pressure on the diaphragm, and correspondingly greater resistance to valve core movement. The forces of the return spring and the valve core spring cancel each other out, ensuring that the pressure on both sides of the diaphragm is nearly equal, reducing diaphragm deformation. The diaphragm is made of elastic rubber material. If the pressure on both sides is different, the diaphragm will stretch and enlarge like a balloon, resulting in an uncontrollable shape.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0017] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of this application are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0018] Figure 1 A three-dimensional structural schematic diagram of the high-precision proportional valve of Embodiment 1 of this application is shown; Figure 2 A half-sectional schematic diagram of the high-precision proportional valve of Embodiment 1 of this application is shown; Figure 3 It shows Figure 2 Enlarged view of a portion of point A in the middle; Figure 4 A half-sectional schematic diagram of the high-precision proportional valve of Embodiment 2 of this application is shown; Figure 5 This shows the valve core in the closed state. Figure 4 Enlarged view of a portion of point B in the middle; Figure 6 This shows the valve core in the open state. Figure 4 Enlarged view of a portion of point B in the middle; Figure 7 A half-sectional schematic diagram of the high-precision proportional valve of Embodiment 3 of this application is shown.

[0019] Explanation of the labels in the diagram: X, first direction; 1. Hydraulic unit; 2. Valve body; 3. Valve core; 4. Valve cover; 5. Diaphragm; 6. Drive component; 7. Tray; 8. Valve core spring; 9. Screw; 10. Stepped chamber; 11. Input end; 12. Output end; 13. First chamber; 14. Second chamber; 15. First sealing element; 16. Second sealing element; 17. Stepped pipe; 18. First pipe section; 19. Second pipe section; 20. Straight pipe; 21. Air inlet; 22. Air outlet; 23. Upper hole; 24. End cap; 25. ... 1. Piston; 26. Second piston; 27. Plug; 41. Buffer chamber; 42. Center hole; 51. Inner sealing part; 52. Outer sealing part; 53. Outer connecting part; 54. Inner folding part; 55. Outer folding part; 56. Inner connecting part; 57. Return spring; 58. Snap ring; 59. Support ring; 61. Coil; 62. Inner cylinder; 63. Iron core; 64. Mounting bracket; 65. Adjusting cylinder; 66. Adjusting spring; 67. Adjusting screw; 68. Vent hole; 69. Stepper motor. Detailed Implementation

[0020] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Example 1: like Figure 1 , Figure 2 and Figure 3 As shown, this application provides a high-precision proportional valve, including a valve body 2, a valve core 3, a valve cover 4, a diaphragm 5, a drive element 6, and a hydraulic unit 1. The valve core 3 is installed on the valve body 2 to control the flow rate of the valve body 2 channel. The inner sealing part 51 of the diaphragm 5 is installed on the valve core 3, and the outer sealing part 52 of the diaphragm 5 is installed on the valve body 2 through the valve cover 4. The hydraulic unit 1 has an input end 11 and an output end 12, with the cross-sectional area of ​​the output end 12 being larger than that of the input end 11. The drive element 6 drives the input end 11 to move, and the output end 12 drives the valve core 3 to move. The moving distance of the input end 11 is greater than that of the output end 12. The cross-sectional area is the cross-sectional area perpendicular to the liquid flow direction of the hydraulic unit 1. A better adjustment effect can be achieved when the ratio of the cross-sectional areas of the input end 11 to the output end 12 is less than 1:2.

[0022] like Figure 1 , Figure 2 and Figure 3As shown, the valve body 2 has an inlet 21 and an outlet 22, which are separated by the valve core 3. The outlet 22 and the diaphragm 5 are in the same chamber, and their pressures are close to or the same. Thus, when the pressure in the outlet 22 decreases, the pressure on one side of the diaphragm 5 decreases, causing the diaphragm 5 to drive the valve core 3 to move in the first direction, which is the direction in which the proportional valve opening increases. A buffer chamber 41 can be formed between the diaphragm 5 and the valve cover 4. The buffer chamber 41 is connected to the outside through a buffer hole, so that the buffer chamber 41 can maintain the same pressure as atmospheric pressure. Generally speaking, the first direction is vertically downward, which is optimal. If the first direction is changed to a horizontal direction, the friction of the iron core 63 will increase, and other parameters will also need to be modified and adjusted accordingly. In non-essential cases, the proportional valve is installed and used with the first direction vertically downward.

[0023] like Figure 2 and Figure 3 As shown, in one embodiment, the driving component 6 is an electromagnet. The electromagnet includes a coil 61, an inner cylinder 62, an iron core 63, a mounting bracket 64, an adjusting cylinder 65, an adjusting spring 66, and an adjusting screw 67. The coil 61 is wound around the outer side of the inner cylinder 62, and the iron core 63 is located at the center of the inner cylinder 62. The mounting bracket 64 fixes the inner cylinder 62 to the valve cover 4. The adjusting cylinder 65 is fixed to one end of the inner cylinder 62 by the mounting bracket 64. The adjusting screw 67 is located in the adjusting cylinder 65, and the adjusting spring 66 is located between the adjusting screw 67 and the iron core 63. The pressure of the adjusting spring 66 on the iron core 63 can be adjusted by adjusting the position of the adjusting screw 67. A valve core spring 8 is provided between the valve core 3 and the valve body 2, and the valve core spring 8 exerts a closing force on the valve core 3. An exhaust hole 68 is provided at the center of the adjusting screw 67, or an exhaust hole 68 is provided in the adjusting cylinder 65. The exhaust hole 68 can balance the air pressure changes generated when the iron core 63 moves. A detachable end cap 24 is provided at the lower opening of the valve body 2 for easy installation of the valve core 3.

[0024] like Figure 2 and Figure 3 As shown, in one embodiment, the hydraulic unit 1 is provided with a stepped cavity 10, which includes a first cavity 13 and a second cavity 14. The inner diameter of the first cavity 13 is smaller than the inner diameter of the second cavity 14. The first cavity 13 is provided with a first sealing element 15, and the second cavity 14 is provided with a second sealing element 16. Liquid is provided in the stepped cavity 10 so that when the first sealing element 15 moves axially, the second sealing element 16 moves axially at the same time.

[0025] like Figure 2 and Figure 3As shown, in one possible embodiment, the hydraulic unit 1 is provided with a stepped pipe 17, which includes a first pipe section 18 and a second pipe section 19. The diameter of the first pipe section 18 is smaller than the diameter of the second pipe section 19. The first pipe section 18 and the second pipe section 19 are connected by an annular section or a conical section. A stepped cavity 10 is formed inside the stepped pipe 17, so that the first pipe section 18 forms a first cavity 13 and the second pipe section 19 forms a second cavity 14. In one possible embodiment, the stepped pipe 17 can be designed in a curved shape, for example, the first pipe section 18 is perpendicular to the second pipe section 19, and the moving direction of the iron core 63 is perpendicular to the moving direction of the valve core 3. In this way, the direction with more space can be selected to set the electromagnet according to the actual space layout, so that the overall structure design of the water heater is more compact and the compatibility is stronger. Hydraulic oil is provided in the stepped cavity 10, and the hydraulic oil has a certain lubricating effect on the stepped pipe 17, so that the frictional resistance of the first sealing member 15 and the second sealing member 16 is small. The stepped tube 17 is made of aluminum or copper and cannot be made of ferromagnetic materials, as this would reduce the driving force of the iron core 63. The mounting bracket 64 can be equipped with a positioning bracket to position the stepped tube 17 individually, or it can be axially positioned with the assistance of the adjusting cylinder 65.

[0026] like Figure 2 and Figure 3 As shown, in one embodiment, a first sealing element 15 is provided in the first pipe section 18, and a second sealing element 16 is provided in the second pipe section 19. The first sealing element 15, the second sealing element 16, and the stepped pipe 17 form a closed stepped cavity 10. The first sealing element 15 and the second sealing element 16 are equivalent to the lever principle, which can amplify the force from the input end 11 to the output end 12 and refine the movement distance, thereby improving accuracy.

[0027] like Figure 2 and Figure 3 As shown, in one embodiment, the first sealing member 15 is driven by the driving member 6, and the second sealing member 16 drives the valve core 3 to move. The first sealing member 15 and the iron core 63 are an integral structure, that is, an annular sealing ring is provided outside the iron core 63, so that the iron core 63 and the first pipe section 18 are sealed. The second sealing member 16 is the second piston 26, which is provided with a sealing ring to seal with the second pipe section 19. The valve cover 4 is provided with a central hole 42 so that the valve core 3 passes through the central hole and directly abuts against the second piston 26.

[0028] like Figure 2 and Figure 3 As shown, in one possible embodiment, the second sealing member 16 is provided with an oil injection hole, which is eccentrically positioned relative to the second sealing member 16, and the oil injection hole is provided with a plug 27. The second piston 26 and the plug 27 can be made of injection molded material, which makes them lighter.

[0029] The high-precision proportional valve of this application can be used in combination with a stop valve, or it can be directly integrally machined with the valve body 2 and the stop valve housing. It is mainly used in gas water heaters, capable of handling different water flow velocities and maintaining a small temperature fluctuation range, thus providing higher precision control of gas flow and reducing the minimum opening adjustment distance. It is suitable for proportional valves driven by electromagnetic drives and stepper motors 69. Furthermore, the embodiments of this application can amplify the output force of the drive component 6, showing good results when used in electro-hydraulic controlled proportional valves, especially high-frequency response electro-hydraulic proportional valves, which can improve control accuracy and stability.

[0030] Example 2: like Figure 4 , Figure 5 and Figure 6 As shown, the difference from Embodiment 1 is that the hydraulic unit 1 is provided with a straight pipe 20. A sealing ring is provided between the straight pipe 20 and the valve cover 4 to seal the straight pipe 20 in the valve cover 4. A first cavity 13 is formed inside the straight pipe 20. A central hole 42 is provided in the center of the valve cover 4, and a second cavity 14 is formed by the central hole 42. A first sealing element 15 is provided in the first cavity 13. The second cavity 14 is sealed by a diaphragm 5, that is, the diaphragm 5 acts as a second sealing element 16. When the first sealing element 15 moves, the diaphragm 5 drives the valve core 3 to move axially. The straight pipe 20 can be stretched and formed, and has a relatively thin thickness. The valve cover 4 is cast and can have a good supporting effect. If the straight pipe 20 and the valve cover 4 are integrally formed, the thickness of the straight pipe 20 will be increased, which will reduce the electromagnetic force generated by the iron core 63. Therefore, a split structure is used as much as possible. In addition, the split structure can be used with other proportional valve parts, reducing the development cost of parts and having better economic benefits.

[0031] like Figure 5 and Figure 6 As shown, in one embodiment, the diaphragm 5 includes an outer sealing portion 52, an outer connecting portion 53, an inner folding portion 54, an outer folding portion 55, an inner connecting portion 56, and an inner sealing portion 51. The inner folding portion 54 and the outer folding portion 55 extend axially along the valve core 3. The outer sealing portion 52, the outer connecting portion 53, the outer folding portion 55, the inner folding portion 54, the inner connecting portion 56, and the inner sealing portion 51 are connected sequentially. The outer diameters of the outer sealing portion 52, the outer connecting portion 53, the outer folding portion 55, the inner folding portion 54, the inner connecting portion 56, and the inner sealing portion 51 decrease sequentially, so that the outer sealing portion 52, the outer connecting portion 53, the outer folding portion 55, the inner folding portion 54, the inner connecting portion 56, and the inner sealing portion 51 are arranged radially. The outer sealing part 52, the outer connecting part 53, the inner folding part 54, the outer folding part 55, the inner connecting part 56, and the inner sealing part 51 are all annular structures. The outer sealing part 52 is fixed to the valve body 2 by the valve cover 4, and the inner sealing part 51 is fixed to the valve core 3 by the retaining ring 58 and the support ring 59, so as to achieve synchronous movement with the valve core 3.

[0032] like Figure 5and Figure 6 As shown, in one embodiment, a tray 7 is provided below the diaphragm 5. The outer diameter of the tray 7 is smaller than the inner diameter of the upper hole 23 of the valve body 2. The outer edge of the tray 7 is bent downwards. The inner fold 54 and the outer fold 55 are located between the outer edge of the tray 7 and the upper hole 23. The tray 7 is fixed to the valve core 3. The small gap between the outer edge of the tray 7 and the upper hole 23 allows the tray 7 to provide good support for the diaphragm 5, keeping the diaphragm 5 as flat as possible when the valve core 3 moves smoothly. When there is a large pressure change in the air outlet 22 or when the valve core 3 is adjusted rapidly, the diaphragm 5 can bend and stretch, playing a buffering role. Figure 6 As shown, when the tray 7 moves along the first direction, the inner fold 54 at least partially flips outward to a position flush with the outer fold 55. The upper hole 23 of the valve body 2 is a tapered hole, which facilitates processing and reduces the effective working area of ​​the second sealing element 16, increases the displacement of the diaphragm 5, and balances the trend of magnetic force variation caused by different currents. The outer fold 55 can be set with the same tilt angle as the upper hole 23, and the inner fold 54 is tilted in the opposite direction to the outer fold 55. This makes it easier for the inner fold 54 to flip. The inner fold 54 is symmetrically arranged relative to the outer fold 55, so that after the inner fold 54 flips, it fits tightly with the upper hole 23, making the movement of the valve core 3 more stable.

[0033] like Figure 4 and Figure 6 As shown, in one possible embodiment, when the cross-sectional area ratio of the input end 11 to the output end 12 is greater than 1:4, for example, when the cross-sectional area ratio of the input end 11 to the output end 12 is greater than 1:3, a return spring 57 is provided between the diaphragm 5 and the first sealing member 15. When the first sealing member 15 approaches the diaphragm 5, it squeezes the return spring 57. When the pressure in the inner cavity of the valve body 2 drops rapidly, the return spring 57 pushes the valve core 3 to move along the first direction, increasing the opening of the proportional valve. When the pressure in the intake passage 21 changes, the pressure in the outlet passage 22 also changes accordingly. For example, when the pressure in the outlet passage 22 suddenly increases, the pressure below the diaphragm 5 is greater than the pressure above it. The diaphragm 5 pushes the valve core 3 upward, the flow rate of the proportional valve decreases, the pressure in the outlet passage 22 decreases, and the upward movement of the diaphragm 5 can push the iron core 63 upward. This has a certain pressure stabilization effect, avoiding large-scale pressure fluctuations that affect the stability of gas combustion, resulting in more complete combustion and lower energy consumption. The ratio of the stiffness coefficient of the return spring 57 to that of the valve core spring 8 is 1:2. Thus, the force changes of the return spring 57 and the valve core spring 8 are the same and can cancel each other out. In this way, the pressure below the diaphragm 5 is equal to the pressure above the diaphragm when the valve core temperature is reached, so that the diaphragm 5 maintains a stable shape. This results in higher control accuracy of the proportional valve.

[0034] Example 3: like Figure 7As shown, the difference from Embodiment 1 is that the driving component 6 is a stepper motor 69. The stepper motor 69 is driven by the screw 9 and the first piston 25. The screw 9 has a threaded structure inside so that the first piston 25 moves in a straight line when the screw 9 rotates. The first piston 25 has an anti-rotation groove on one side so that the first piston 25 does not rotate when the screw 9 rotates. The first piston 25 is disposed within the first pipe section 18, and the second piston 26 is disposed within the second pipe section 19. The first piston 25 can push the second piston 26 to move. The moving distance of the first piston 25 and the second piston 26 is inversely proportional to the diameter of the first pipe section 18 and the second pipe section 19. For proportional valves requiring high precision, this structure can reduce the moving distance of the single pulse valve core 3 and increase the precision of the valve core 3 movement control. For proportional valves with large flow rates, this structure can increase the output force and achieve precise control of larger flow rates. That is, the same stepper motor 69 can achieve improved precision and achieve control of larger flow rates using the results of this application. For proportional valves with the same flow rate, the power of the stepper motor 69 can be reduced, reducing the cost of the stepper motor 69. In addition, the transmission structure can be simplified, reducing the cost of the transmission structure. Using a mechanical structure to achieve a high transmission ratio is costly. The technical solution of this application only increases the volume to a certain extent, and has a significant advantage in production cost. The second piston 26 is connected to the valve core 3 via a buffer spring. When the pressure below the diaphragm 5 changes abruptly, the valve core 3 can be moved under the pressure difference of the diaphragm 5. For example, if the pressure in the channel suddenly increases, the pressure below the diaphragm 5 increases, and the valve core 3 moves upward under the action of the diaphragm 5, reducing the opening of the proportional valve and thus reducing the pressure, which has a certain inhibitory effect on changes in external pressure. If the pressure in the channel suddenly decreases, the pressure below the diaphragm 5 decreases, and the valve core 3 moves downward under the action of the diaphragm 5, increasing the opening of the proportional valve and thus increasing the pressure, which also has a certain inhibitory effect on changes in external pressure.

[0035] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-precision proportional valve, characterized in that, The valve body (2), valve core (3), valve cover (4), diaphragm (5), drive unit (6), and hydraulic unit (1) are included. The valve core (3) is installed on the valve body (2) to control the flow rate of the valve body (2) channel. The inner sealing part (51) of the diaphragm (5) is installed on the valve core (3), and the outer sealing part (52) of the diaphragm (5) is installed on the valve body (2) through the valve cover (4). The hydraulic unit (1) is provided with an input end (11) and an output end (12). The cross-sectional area of ​​the output end (12) is larger than that of the input end (11). The drive unit (6) drives the input end (11) to move, and the output end (12) drives the valve core (3) to move. The moving distance of the input end (11) is greater than that of the output end (12).

2. The high-precision proportional valve according to claim 1, characterized in that, The driving component (6) is an electromagnet or a stepper motor (69).

3. The high-precision proportional valve according to claim 2, characterized in that, The hydraulic unit (1) is provided with a stepped cavity (10), which includes a first cavity (13) and a second cavity (14). The inner diameter of the first cavity (13) is smaller than the inner diameter of the second cavity (14). The first cavity (13) is provided with a first sealing element (15), and the second cavity (14) is provided with a second sealing element (16). The stepped cavity (10) is provided with liquid so that when the first sealing element (15) moves axially, the second sealing element (16) moves axially at the same time.

4. The high-precision proportional valve according to claim 3, characterized in that, The hydraulic unit (1) is provided with a stepped pipe (17), which includes a first pipe section (18) and a second pipe section (19). The diameter of the first pipe section (18) is smaller than the diameter of the second pipe section (19). A stepped cavity (10) is formed inside the stepped pipe (17) such that the first pipe section (18) forms the first cavity (13) and the second pipe section (19) forms the second cavity (14).

5. The high-precision proportional valve according to claim 4, characterized in that, The first pipe section (18) is provided with the first sealing element (15), and the second pipe section (19) is provided with the second sealing element (16). The first sealing element (15) is driven by the driving element (6), and the second sealing element (16) drives the valve core (3) to move.

6. The high-precision proportional valve according to claim 5, characterized in that, The second sealing member (16) is provided with an oil injection hole, which is eccentrically positioned relative to the second sealing member (16) and is provided with a plug (27).

7. The high-precision proportional valve according to claim 1 or 2, characterized in that, The hydraulic unit (1) is provided with a straight pipe (20), which is sealed and installed on the valve cover (4). A first cavity (13) is formed inside the straight pipe (20), and a second cavity (14) is formed in the center of the valve cover (4). A first sealing element (15) is provided in the first cavity (13), and the second cavity (14) is sealed by the diaphragm (5). When the first sealing element (15) moves, the diaphragm (5) drives the valve core (3) to move axially.

8. The high-precision proportional valve according to claim 7, characterized in that, The diaphragm (5) includes an outer sealing part (52), an outer connecting part (53), an inner folding part (54), an outer folding part (55), an inner connecting part (56), and an inner sealing part (51). The inner folding part (54) and the outer folding part (55) extend axially along the valve core (3). The outer sealing part (52), the outer connecting part (53), the outer folding part (55), the inner folding part (54), the inner connecting part (56), and the inner sealing part (51) are connected in sequence. The outer diameters of the outer sealing part (52), the outer connecting part (53), the outer folding part (55), the inner folding part (54), the inner connecting part (56), and the inner sealing part (51) decrease in sequence, so that the outer sealing part (52), the outer connecting part (53), the outer folding part (55), the inner folding part (54), the inner connecting part (56), and the inner sealing part (51) are arranged radially.

9. The high-precision proportional valve according to claim 8, characterized in that, A tray (7) is provided below the diaphragm (5). The outer diameter of the tray (7) is smaller than the inner diameter of the upper hole (23) of the valve body (2). The inner fold (54) and the outer fold (55) are located between the tray (7) and the upper hole (23). The tray (7) is fixed to the valve core (3). When the tray (7) moves along the first direction, the inner fold (54) is at least partially flipped outward to be flush with the outer fold (55).

10. The high-precision proportional valve according to claim 9, characterized in that, A reset spring (57) is provided between the diaphragm (5) and the first sealing member (15). When the first sealing member (15) approaches the diaphragm (5), it squeezes the reset spring (57). When the pressure inside the valve body (2) drops rapidly, the reset spring (57) pushes the valve core (3) to move along the first direction to increase the opening of the proportional valve.

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