Proportional valve capable of quantitatively sucking and discharging liquid

Abstract

The proportional valve comprises a valve body, a valve element, a movable iron core, a valve plate and a check valve, a liquid inlet and a liquid outlet are formed in the valve body, and the check valve is arranged at the liquid inlet; a valve element capable of moving up and down is arranged in a mounting groove of the valve body, the upper end of the valve element is in transmission connection with a movable iron core, and a valve plate is arranged between the valve element and the movable iron core. A liquid through hole is formed in the upper end of the valve element; the valve plate, the movable iron core and the mounting groove form a first cavity, and the valve plate, the valve core and the mounting groove form a second cavity; the liquid outlet is communicated with the first cavity through a first channel, and the liquid inlet is communicated with the second cavity through a second channel. The coil controls the movable iron core to move to drive the valve element to move up and down, so that the volume of the second cavity is changed, and liquid suction and discharge are controlled. The proportional valve integrates opening, closing, adjusting, conveying and one-way flowing, is compact in structure and diversified in function, and solves the problems that a traditional proportional valve is single in function, prone to backflow and free of self-suction and quantitative conveying capacity.

Description

Technical Field

[0001] This invention relates to the field of fluid control technology, and more specifically to a proportional valve capable of quantitatively drawing and discharging liquid. Background Technology

[0002] Proportional valves are widely used in industrial automation, medical equipment, and environmental engineering for precise control of fluid flow or pressure. Traditional proportional valves typically rely on inlet pressure for flow regulation; when pipeline pressure is insufficient, their function degenerates into a simple on / off valve, making continuous flow regulation or stable delivery difficult. Furthermore, due to the lack of unidirectional protection, fluid backflow is prone to occur during pressure fluctuations, affecting system stability. In addition, traditional proportional valves lack self-priming capability and precise metering function, limiting their use in applications requiring accurate metering independent of inlet pressure. Therefore, a proportional valve capable of metering liquid intake and exhaust was designed to address these issues.

[0003] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a proportional valve capable of quantitatively aspirating and discharging liquid.

[0005] To achieve the above and other related objectives, the technical solution provided by this invention is: a proportional valve for quantitatively aspirating and discharging liquid, comprising: The valve body has an inlet and an outlet, and the inlet is equipped with a check valve. The upper end face of the valve body is provided with a cylindrical mounting groove, and a valve core that can move up and down is provided in the mounting groove. The upper end of the valve core is connected to a moving iron core, and a valve plate is provided between the valve core and the moving iron core. The upper end of the valve core is provided with a plurality of liquid passage holes, which are arranged around the center line of the valve core, and the valve plate is covered on the upper end surface of the valve core. The valve plate, together with the moving iron core above and the mounting groove, forms a first cavity. The valve plate, together with the valve core below and the mounting groove, forms a second cavity. The liquid outlet is connected to the first cavity through a first channel located on the side of the mounting groove, and the liquid inlet is connected to the second cavity through a second channel located at the lower end of the mounting groove.

[0006] This solution precisely changes the volume of the second chamber by controlling the up-and-down movement of the valve core, and uses a two-way one-way valve group composed of a valve plate and an inlet check valve to guide the fluid through in one direction, thus achieving precise quantitative intake and discharge functions.

[0007] Furthermore, the system also includes a housing, which is positioned above the valve body. The housing is cylindrical with an opening at its upper end and has a mounting hole corresponding to the mounting groove. The moving iron core is disposed inside the housing, and the housing also contains a stationary iron core positioned above the moving iron core and a coil sleeved on the outside of the moving iron core. The stationary iron core is located at the upper end of the housing and covers the coil. A compression spring is disposed between the stationary iron core and the moving iron core, with the upper end of the compression spring sleeved on the lower end of the stationary iron core and the lower end of the compression spring sleeved on the upper end of the moving iron core. The lower end of the moving iron core passes through the mounting hole. This solution achieves automatic control of the valve core through electromagnetic drive and spring reset structure, improving the valve's response speed and reliability.

[0008] Furthermore, when the coil is not energized, the moving iron core is acted upon by the spring force of the compression spring, causing the valve core to move downwards, thus reducing the volume of the second cavity and closing the second channel. When the coil is energized, the moving iron core is acted upon by the attraction force of the electromagnet, causing the valve core to move upwards, thus increasing the volume of the second cavity and opening the second channel. This solution controls the movement of the valve core by switching the coil on and off, thereby changing the volume of the second cavity and opening / closing the channel, thus regulating the flow rate and achieving quantitative suction and discharge.

[0009] Furthermore, the lower end of the stationary iron core is provided with a frustum-shaped docking groove, the diameter of which gradually increases from the inside to the outside. The upper end of the moving iron core is provided with a frustum-shaped docking end that matches the shape of the docking groove, and the docking end is designed to enter the docking groove. In this design, the guiding structure of the docking groove and the docking end ensures smooth movement of the moving iron core, reduces wear, and improves the working stability of the valve.

[0010] Furthermore, an adjusting screw capable of vertical movement is disposed above the moving iron core. The adjusting screw passes through the middle of the stationary iron core, with its upper end extending beyond the upper end of the stationary iron core and its lower end extending into the mating groove. An adjusting nut is fitted onto the upper end of the adjusting screw, and a washer is placed between the adjusting nut and the stationary iron core. This solution limits the movement range of the moving iron core by adjusting the screw, precisely controlling the valve core stroke and achieving fine adjustment of flow rate and quantitative delivery.

[0011] Furthermore, a stepped hole is formed on the lower end face of the valve core, and a sealing plug is disposed within the stepped hole. The lower end of the sealing plug protrudes from the lower end face of the valve core. A raised ring is provided at the outlet of the second channel within the second cavity, and the raised ring is positioned vertically corresponding to the sealing plug. In this design, the cooperation between the sealing plug and the raised ring enhances the sealing performance of the second channel, prevents liquid leakage, and improves the reliability of valve closure.

[0012] Furthermore, an annular groove is formed on the upper end face of the valve core, and the annular groove is connected to each of the liquid passage holes. The valve plate covers the annular groove. In this design, the annular groove stores liquid and provides uniform pressure to the valve plate, extending the service life of the valve plate and improving sealing performance.

[0013] Furthermore, the upper end of the valve core is provided with several mating posts, which are arranged around the center line of the valve core. The valve plate has several mating holes that correspond one-to-one with the mating posts, and the mating posts are inserted into the mating holes accordingly. In this design, the mating posts and mating holes ensure accurate positioning of the valve plate, prevent misalignment or displacement of the valve plate, and ensure normal operation of the valve plate.

[0014] Furthermore, a protruding stud is provided at the middle of the upper end of the valve core, and a protruding connecting post is provided at the lower end of the moving iron core. The connecting post has a threaded hole inside, and the stud is connected to the threaded hole. In this design, the connection between the stud and the threaded hole ensures a secure connection between the valve core and the moving iron core, resulting in stable transmission and facilitating assembly and maintenance.

[0015] Furthermore, a first sealing ring is fitted around the lower outer ring of the moving iron core; a second sealing ring is fitted around the outer ring of the valve core; and a third sealing ring is provided between the lower end of the housing and the upper end of the valve body. In this design, multiple sealing rings ensure the sealing performance of the valve body, housing, and moving parts, preventing liquid leakage and improving overall reliability.

[0016] Furthermore, the check valve is a duckbill valve made of flexible material. The duckbill valve utilizes elastic deformation to achieve unidirectional flow, preventing blockage, providing a good seal, and is easy to install.

[0017] Furthermore, the adjusting screw is equipped with a scale to indicate the adjustment range. The scale facilitates precise adjustment of the moving iron core stroke by the operator, improving the convenience and accuracy of adjustment.

[0018] Furthermore, the sealing plug has a T-shaped structure and is made of rubber material. The T-shaped structure facilitates installation and sealing, and the rubber material provides good elasticity and sealing performance.

[0019] Furthermore, the inlet and outlet are located on the same side of the valve body. Having the inlet and outlet on the same side facilitates pipe connections and spatial layout, improving installation efficiency.

[0020] Furthermore, the lower end of the valve core is chamfered. The chamfered structure can reduce friction and resistance during valve core movement and improve the smoothness of movement.

[0021] Due to the application of the above technical solution, the beneficial effects of this invention compared with the prior art are as follows: This invention ingeniously integrates electromagnetic drive, piston pump, and check valve functions into a compact valve body. It not only realizes the flow regulation function of traditional proportional valves, but also breaks through the limitation of its dependence on inlet pressure, possessing independent self-priming capability and precise quantitative metering function. At the same time, it provides dual anti-backflow protection through duckbill valve and valve plate, greatly expanding the application field and reliability of proportional valves. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the proportional valve of the present invention; Figure 2 This is a schematic diagram of the exploded structure of the proportional valve of the present invention; Figure 3 This is a cross-sectional view of the proportional valve of the present invention; Figure 4 This is a schematic diagram of the assembly structure of the stationary iron core, the moving iron core, and the valve core of the present invention. Figure 5 This is a schematic diagram of the exploded structure of the valve plate, valve core, and sealing plug of the present invention; In the above attached figures, 1. Valve body; 11. Liquid inlet; 12. Liquid outlet; 13. Mounting groove; 14. First channel; 15. Second channel; 151. Protruding ring; 2. Housing; 21. Mounting holes; 3. Valve core; 31. Fluid passage hole; 32. Stepped hole; 33. Annular groove; 34. Connecting post; 35. Stud; 36. Second sealing ring; 4. Moving iron core; 41. Connecting end; 42. Connecting post; 43. First sealing ring; 5. Valve plate; 51. Connecting hole; 6. Check valve; 71. First cavity; 72. Second cavity; 8. Static iron core; 81. Connecting groove; 9. Coil; 10. Compression spring; 16. Adjusting screw; 17. Adjusting nut; 18. Washer; 19. Sealing plug; 20. Third sealing ring. Detailed Implementation

[0023] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0024] It should be noted that in the description of this invention, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms 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 element 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," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. The terms "horizontal," "vertical," and "suspended," etc., do not indicate that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0027] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0028] Example: See appendix Figure 1 Appendix Figure 2 and attached Figure 3As shown, the proportional valve for quantitative liquid aspiration and discharge provided in this embodiment mainly includes three parts: valve body 1, electromagnetic drive assembly, and piston valve core 3.

[0029] Valve body 1 assembly: includes valve body 1, inlet 11, outlet 12, and internal flow channels and cavities.

[0030] Electromagnetic drive assembly: including housing 2, stationary iron core 8, coil 9, moving iron core 4 and compression spring 10, responsible for providing the driving force for the movement of valve core 3.

[0031] Piston valve core 3 assembly: including valve core 3, valve plate 5 and sealing plug 19, is the core component that directly controls the flow and metering of liquid.

[0032] The assembly relationships between the components are as follows: Valve body 1 and flow channel: The valve body 1 is made of corrosion-resistant engineering plastics (such as POM) or metals (such as stainless steel). The inlet 11 and outlet 12 are located on the same side of the valve body 1, which facilitates pipeline integration and installation.

[0033] The valve body 1 has a precision-machined cylindrical mounting groove 13 to accommodate the valve core 3. A first channel 14 is formed on the upper side wall of the mounting groove 13, which connects the upper part of the mounting groove 13 to the liquid outlet 12. A second channel 15 is formed in the center of the bottom of the mounting groove 13, which connects to the liquid inlet 11.

[0034] A raised ring 151 is designed at the outlet of the second channel 15. The raised ring 151 is slightly higher than the bottom surface of the mounting groove 13. Its function is to serve as a sealing surface, forming a tight fit with the sealing plug 19 at the bottom of the valve core 3, thereby enhancing the sealing effect when closed.

[0035] Piston valve core 3-piece assembly: The valve core 3 is essentially a precision piston. Its outer circle is clearance-fitted with the inner wall of the mounting groove 13 and is fitted with a second sealing ring 36 (such as an O-ring) to ensure the sealing of the second cavity 72 when the valve core 3 moves up and down.

[0036] The upper surface of the valve core 3 is machined with multiple fluid passage holes 31, which are distributed circumferentially around the center line of the valve core 3. All fluid passage holes 31 are connected to an annular groove 33 above. The design of the annular groove 33 allows the liquid pressure to be applied more evenly to the back of the valve plate 5.

[0037] The upper end of the valve core 3 is also provided with multiple docking posts 34 and a central stud 35. The docking posts 34 are used to position the valve plate 5.

[0038] Valve plate 5 is made of a highly elastic rubber material (such as silicone rubber or fluororubber), and has mating holes 51 corresponding to mating posts 34. See Appendix. Figure 5 As shown, during assembly, the mating post 34 passes through the mating hole 51, allowing the valve plate 5 to be precisely positioned and laid flat on the upper end face of the valve core 3, covering the annular groove 33 and all the liquid passage holes 31. The valve plate 5 acts as a one-way valve, allowing liquid to enter the first chamber 71 from the second chamber 72 through the liquid passage holes 31, and closing it otherwise.

[0039] The lower end of the valve core 3 has a stepped hole 32, into which a T-shaped sealing plug 19 is pressed. The sealing plug 19 is made of rubber (such as NBR) that is harder than the valve plate 5, and its head protrudes slightly from the lower end face of the valve core 3 by about 0.5~1mm. When the valve core 3 moves downward, the protruding sealing plug 19 presses against the convex ring 151 at the outlet of the second channel 15, forming a reliable line seal or surface seal. The lower edge of the valve core 3 is also designed with a chamfer to reduce fluid resistance and friction during movement.

[0040] Electromagnetic drive components: The housing 2 is fixed to the upper end of the valve body 1 by screws or clips, and a third sealing ring 20 is installed at the mating surface to prevent leakage.

[0041] The moving iron core 4 is installed in the mounting hole 21 inside the housing 2, and its lower end is fastened to the stud 35 of the valve core 3 through the threaded hole in the connecting post 42 to ensure synchronous transmission. The outer circle of the moving iron core 4 is fitted with a first sealing ring 43, which isolates the electromagnetic drive cavity from the fluid cavity below.

[0042] Coil 9 is wound around the iron core frame and fixed inside the housing 2. When it is energized, it will generate a magnetic field.

[0043] The stationary iron core 8 is press-fitted or fixed to the upper port of the housing 2, enclosing the main body of the coil 9. The cable of the coil 9 passes through the upper hole of the stationary iron core 8. The lower end of the stationary iron core 8 is machined with a frustum-shaped mating groove 81.

[0044] Compression spring 10 is placed between stationary iron core 8 and moving iron core 4, with its two ends respectively fitted onto the protruding structures of both. See Appendix. Figure 4 As shown, a downward, continuous restoring force is provided for the moving iron core 4 and the valve core 3.

[0045] The upper end of the moving iron core 4 is machined with a frustum-shaped docking end 41 that matches the shape of the docking groove 81. When the moving iron core 4 is attracted and moves upward, the docking end 41 can be smoothly guided into the docking groove 81. This not only improves the stability of the movement, but also reduces impact and noise, and optimizes the magnetic circuit efficiency.

[0046] Regulation mechanism: The adjusting screw 16 passes through the threaded hole in the middle of the stationary iron core 8, and its lower end can extend into the mating groove 81.

[0047] The upper end of the adjusting screw 16 is equipped with an adjusting nut 17, and a wave-shaped shim 18 can be set between the two to eliminate thread clearance and provide anti-loosening friction.

[0048] By rotating the adjusting nut 17, the depth to which the adjusting screw 16 extends into the mating groove 81 can be precisely controlled. This depth determines the limit position of the upward movement of the moving iron core 4, thereby limiting the maximum lift of the valve core 3.

[0049] The adjusting screw 16 can be engraved with scales, making it convenient for operators to read and set the maximum stroke intuitively.

[0050] Check valve 6: A duckbill valve is installed at the inlet 11 as a check valve 6. The duckbill valve is made of flexible rubber, and its natural structure allows liquid to flow only from the outside of the valve body 1 to the inside of the inlet 11, which can effectively prevent liquid backflow and impurity blockage.

[0051] Working principle: The proportional valve designed in this invention has two basic operating modes: continuous energization regulation mode and pulse energization quantitative suction and discharge mode.

[0052] Mode 1: Continuous energization control mode can be used as a proportional valve / control valve. Initial state: Coil 9 is de-energized. Under the preload of the compression spring 10, the moving iron core 4 and valve core 3 are pushed to their lowest positions. At this time, the sealing plug 19 at the lower end of the valve core 3 presses tightly against the convex ring 151 of the second channel 15, closing the second channel 15. The second cavity 72 is at its smallest volume, the proportional valve is in the closed state, and no liquid flows out.

[0053] The opening and adjustment process involves energizing coil 9: When a continuously changing current is applied to coil 9, an electromagnetic force is generated. This electromagnetic force overcomes the elastic force of the compression spring 10 and the fluid pressure, attracting the moving iron core 4 to move upward.

[0054] The moving iron core 4 drives the valve core 3 to move upward synchronously through the connecting column 42.

[0055] As the valve core 3 moves upward, the sealing plug 19 moves away from the convex ring 151, and the second channel 15 opens accordingly. At the same time, the volume of the second cavity 72 gradually increases, and a negative pressure is formed inside.

[0056] At this time, the duckbill valve at the inlet 11 is opened under the action of pressure difference, and the liquid is drawn into the second chamber 72 from the inlet 11 through the second channel 15.

[0057] Since the first cavity 71 above the valve plate 5 is connected to the liquid outlet 12 through the first channel 14, and there may be back pressure at the rear end of the liquid outlet 12, the pressure on the upper and lower parts of the valve plate 5 is balanced or the pressure on the upper part is slightly higher. Therefore, the valve plate 5 remains closed to prevent the liquid from flowing upward.

[0058] Flow regulation: By precisely controlling the current in the input coil 9, the electromagnetic force can be linearly changed, thereby controlling the lifting height (opening degree) of the moving iron core 4 and the valve core 3. The larger the opening degree, the larger the flow area of ​​the second channel 15, and the greater the flow rate from the inlet 11 to the second chamber 72. The flow rate adjustment range can be set by presetting the maximum stroke of the adjusting screw 16. Thus, continuous and proportional electronic control regulation of the flow rate is achieved.

[0059] Mode 2: Pulse-energized quantitative suction and discharge mode can be used as a metering pump. This mode does not rely on import pressure and has self-priming and quantitative conveying capabilities.

[0060] The coil is energized with 9 pulses during the intake stroke: A short pulse of current is applied to coil 9, generating sufficient electromagnetic force to cause the moving iron core 4 and valve core 3 to move rapidly upward to the maximum stroke, which is limited by adjusting screw 16.

[0061] This process causes the volume of the second cavity 72 to increase dramatically, creating a significant negative pressure vacuum inside.

[0062] Under the action of pressure difference, the duckbill valve of the liquid inlet 11 is opened, and liquid is drawn in.

[0063] At the same time, since the second chamber 72 is under negative pressure, while the first chamber 71 is connected to the atmosphere or system back pressure through the liquid outlet 12, the valve plate 5 is pressed tightly against the upper end face of the valve core 3 by atmospheric pressure or back pressure, keeping it closed and preventing gas or liquid from flowing back.

[0064] This process completes one dose of liquid inhalation.

[0065] The discharge stroke coil is de-energized by 9 pulses: When the pulse current ends, the electromagnetic force disappears. Under the strong restoring force of the compression spring 10, the moving iron core 4 and the valve core 3 move rapidly downward.

[0066] The volume of the second chamber 72 decreases rapidly, and the internal pressure increases abruptly.

[0067] High pressure causes the duckbill valve at inlet 11 to be tightly closed to prevent liquid backflow.

[0068] At the same time, the high-pressure liquid pushes open the valve plate 5, enters the first cavity 71 through the liquid passage 31 and the annular groove 33, and is then forcibly discharged from the liquid outlet 12 through the first channel 14.

[0069] This process completes one quantitative discharge of liquid.

[0070] Quantitative control: With each pulse signal, the valve completes one "intake-out" cycle, delivering a fixed volume of liquid. The single delivery volume is determined by the stroke of valve core 3, i.e., the volume change of the second chamber 72, and can be calibrated by adjusting screw 16. The total delivery volume is controlled by the number of pulses. The delivery rate is controlled by the pulse frequency. This achieves high-precision quantitative delivery.

[0071] This embodiment, through the aforementioned structural design, cleverly integrates the functions of electromagnetic drive, piston pump, and check valve into a compact valve body. It not only achieves the flow regulation function of a traditional proportional valve but also overcomes its dependence on inlet pressure, possessing independent self-priming capability and precise quantitative metering function. Furthermore, the duckbill valve and valve disc provide dual backflow protection, greatly expanding the application range and reliability of the proportional valve.

[0072] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A proportional valve for quantitatively aspirating and discharging liquid, characterized in that, include: The valve body (1) is provided with an inlet (11) and an outlet (12), and the inlet (11) is provided with a check valve (6). The upper end face of the valve body (1) is provided with a cylindrical mounting groove (13), and a valve core (3) that can move up and down is provided in the mounting groove (13). The upper end of the valve core (3) is connected to a moving iron core (4) for transmission, and a valve plate (5) is provided between the valve core (3) and the moving iron core (4). The upper end of the valve core (3) is provided with a plurality of liquid passage holes (31), the liquid passage holes (31) are arranged around the center line of the valve core (3), and the valve plate (5) is covered on the upper end surface of the valve core (3). The valve plate (5), together with the moving iron core (4) above and the mounting groove (13), forms a first cavity (71). The valve plate (5), together with the valve core (3) below and the mounting groove (13), forms a second cavity (72). The liquid outlet (12) is connected to the first cavity (71) through a first channel (14) located on the side of the mounting groove (13). The liquid inlet (11) is connected to the second cavity (72) through a second channel (15) located at the lower end of the mounting groove (13).

2. The proportional valve for quantitative liquid aspiration and dispensing according to claim 1, characterized in that: It also includes a housing (2), which is disposed above the valve body (1). The housing (2) is cylindrical and has an opening at its upper end. The housing (2) has a mounting hole (21) corresponding to the mounting groove (13). The moving iron core (4) is disposed inside the housing (2). Inside the housing (2), there is also a stationary iron core (8) located above the moving iron core (4) and a coil (9) sleeved on the outside of the moving iron core (4). The stationary iron core (8) is located at the upper port of the housing (2) and covers the coil (9). A compression spring (10) is disposed between the stationary iron core (8) and the moving iron core (4). The upper end of the compression spring (10) is sleeved on the lower end of the stationary iron core (8), and the lower end of the compression spring (10) is sleeved on the upper end of the moving iron core (4). The lower end of the moving iron core (4) passes through the mounting hole (21).

3. The proportional valve for quantitative liquid aspiration and dispensing according to claim 2, characterized in that: When the coil (9) is not energized, the moving iron core (4) is subjected to the spring force of the compression spring (10), which drives the valve core (3) to move downward, so that the volume of the second cavity (72) becomes smaller and the second channel (15) is closed. When the coil (9) is energized, the moving iron core (4) is attracted by the electromagnet, which drives the valve core (3) to move upward, making the volume of the second cavity (72) larger and the second channel (15) open.

4. A proportional valve for quantitative liquid aspiration and dispensing according to claim 2, characterized in that: The lower end of the stationary iron core (8) is provided with a frustum-shaped docking groove (81), the diameter of which gradually increases from the inside to the outside. The upper end of the moving iron core (4) is provided with a frustum-shaped docking end (41) that matches the shape of the docking groove (81), and the docking end (41) is configured to be able to enter the docking groove (81).

5. A proportional valve for quantitative liquid aspiration and dispensing according to claim 4, characterized in that: An adjusting screw (16) capable of moving up and down is provided above the moving iron core (4). The adjusting screw (16) passes through the middle of the stationary iron core (8). The upper end of the adjusting screw (16) extends out of the upper end of the stationary iron core (8), and the lower end of the adjusting screw (16) extends into the docking groove (81). An adjusting nut (17) is sleeved on the upper end of the adjusting screw (16), and a washer (18) is provided between the adjusting nut (17) and the stationary iron core (8).

6. A proportional valve for quantitative liquid aspiration and dispensing according to claim 1, characterized in that: The lower end face of the valve core (3) is provided with a stepped hole (32), and a sealing plug (19) is provided in the stepped hole (32). The lower end of the sealing plug (19) protrudes from the lower end face of the valve core (3). The second channel (15) is provided with a raised ring (151) at the outlet of the second cavity (72). The raised ring (151) and the sealing plug (19) are arranged vertically and vertically respectively.

7. A proportional valve for quantitative liquid aspiration and dispensing according to claim 1, characterized in that: The upper end face of the valve core (3) is provided with an annular groove (33), which is connected to each of the liquid passage holes (31), and the valve plate (5) is provided to cover the annular groove (33).

8. A proportional valve for quantitative liquid aspiration and dispensing according to claim 1, characterized in that: The upper end of the valve core (3) is provided with a number of docking posts (34), the docking posts (34) are arranged around the center line of the valve core (3), and the valve plate (5) is provided with a number of docking holes (51) corresponding to the docking posts (34), and the docking posts (34) are inserted into the docking holes (51).

9. A proportional valve for quantitative liquid aspiration and dispensing according to claim 1, characterized in that: The valve core (3) has a protruding stud (35) at the middle of its upper end, and the moving iron core (4) has a protruding connecting post (42) at its lower end. The connecting post (42) has a threaded hole inside, and the stud (35) is connected to the threaded hole.

10. A proportional valve for quantitative liquid aspiration and dispensing according to claim 2, characterized in that: The lower end of the moving iron core (4) is fitted with a first sealing ring (43); the outer ring of the valve core (3) is fitted with a second sealing ring (36); and a third sealing ring (20) is provided between the lower end of the housing (2) and the upper end of the valve body (1).

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