A high-precision flow control proportional solenoid valve

Abstract

The present invention discloses a high-precision flow control proportional solenoid valve, belonging to the technical fields of flow control and valves. It includes a spool assembly, an electromagnet assembly, and a valve body assembly; the spool assembly includes a moving armature; the other end of the suction surface of the moving armature is connected to a gas guide link axially provided with a gas guide through hole, and the gas guide link is connected to a gasket assembly; a circumferential protrusion is provided on the gas guide link, and a leaf spring sleeved on the gas guide link is provided on the mating surface of the circumferential protrusion and the moving armature; an air outlet channel is axially provided on the valve seat; an air inlet channel is axially provided on the plugging port; the gas passes through the gas guide through hole, passes through the gasket assembly, and communicates with the air inlet channel on the plugging port, forming a gas pressure compensation structure. Part of the generated gas pressure acts on the spool assembly, and the other part acts on the valve seat. The component of the gas pressure acting on the spool assembly is used as a compensation force to enhance the sealing effect of the spool assembly.

Description

Technical Field

[0001] The present invention belongs to the technical field of flow control and valves, and relates to a high-precision flow control proportional solenoid valve. Background Art

[0002] A proportional solenoid valve is a special control solenoid valve. Its control principle relies on a special magnetic circuit structure. By inputting an electrical signal, an electromagnetic force is generated to drive the valve core and control the valve opening, so as to achieve stepless adjustment of physical quantities such as the flow rate and pressure of the medium flowing through. It adopts a "position feedback" technology, which can accurately adjust the position of the valve according to the flow control signal, thus meeting the precise control requirements. Therefore, the proportional solenoid valve is a common mechanical device in the field of gas flow control and can be used in medical devices such as ventilators and anesthetic machines. The use environment of these devices requires that the proportional solenoid valve has the characteristics of high control accuracy, low power consumption, long service life, and high pressure resistance. However, the common proportional solenoid valves in this field currently rely only on the deformation of the spring to generate the sealing force for sealing, which will lead to problems such as high power consumption, short service life, and poor high-pressure resistance of the proportional solenoid valve. Summary of the Invention

[0003] The purpose of the present invention is to solve the technical problems that the power consumption, service life, and high-pressure resistance of the proportional solenoid valve in the prior art all need to be further optimized, and to provide a high-precision flow control proportional solenoid valve.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] In the first aspect, the present invention provides a high-precision flow control proportional solenoid valve, which includes a valve core assembly, an electromagnet assembly, and a valve body assembly; the valve body assembly includes a valve seat and a plugging port; the electromagnet assembly and the valve body assembly are cooperatively connected to form a solenoid valve cavity, and the valve core assembly is installed inside the solenoid valve cavity; the valve core assembly includes a moving armature; the other end of the suction surface of the moving armature is connected with a gas guiding link provided with an axially arranged gas guiding through hole, and the gas guiding link is connected with a gasket assembly; a circumferential protrusion is provided on the gas guiding link, and a leaf spring sleeved on the gas guiding link is provided on the mating surface of the circumferential protrusion and the moving armature; the valve seat is axially provided with an air outlet channel; the plugging port is axially provided with an air inlet channel; when the gasket assembly fits with the end face of the plugging port, the solenoid valve is cut off;

[0006] The electromagnet assembly includes a lower yoke and an upper yoke that are cooperatively connected and have an electromagnetic coil disposed in the middle; after the electromagnetic coil is energized, it is used to provide an electromagnetic force to drive the valve core assembly to approach and turn on the solenoid valve; a rubber diaphragm sleeved on the gas guiding link is provided on the mating surface of the upper yoke and the valve seat.

[0007] The present invention is further improved in that:

[0008] The inner ring of the rubber diaphragm is pressed by the circumferential protrusion and the gasket assembly, and the outer ring of the rubber diaphragm is pressed by the valve seat and the upper yoke iron.

[0009] A first valve seat step surface is provided on the valve seat, and a diaphragm bottom ring is provided on the first valve seat step surface; a second upper yoke iron step surface and a first upper yoke iron step surface are sequentially provided on the upper yoke iron along the direction of fluid entering the solenoid valve; a diaphragm top ring is provided on the second upper yoke iron step surface; the rubber diaphragm is pressed by the diaphragm bottom ring and the diaphragm top ring.

[0010] The difference between the inner diameter and the outer diameter of the diaphragm bottom ring is smaller than the difference between the inner diameter and the outer diameter of the diaphragm top ring.

[0011] A protruding first gasket assembly step surface is provided on the contact surface between the gasket assembly and the inner ring of the rubber diaphragm; a protruding second valve seat step surface is provided on the contact surface between the valve seat and the outer ring of the rubber diaphragm.

[0012] The rubber diaphragm has a fabric or fiber interlayer distributed in the warp and weft directions in the thickness direction.

[0013] The suction surface of the moving armature is umbrella-shaped; the umbrella shape is a curved surface formed by connecting a spherical surface and a plurality of conical surfaces.

[0014] The valve seat and the plugging port are coaxially sleeved; the gas inlet of the air inlet channel is set as a tapered hole with a decreasing inner diameter; a curved surface is provided at the transition of the air inlet channel and the air outlet channel on the plugging port, and the curved surface is sequentially tangentally connected by an inner arc surface with a radius R1, a plane with a width S, and an outer arc surface with a radius R2, and the radius R1 is greater than the radius R2.

[0015] A ring groove is provided on the lower yoke iron around the axis, and a central axis is formed on the lower yoke iron after the ring groove is provided, and a central axis step is provided on the central axis; the electromagnetic coil is composed of a coil skeleton and a coil fixed thereon; a step hole that is in interference fit with the central axis step is provided on the coil skeleton to ensure the installation coaxiality of the electromagnetic coil and the lower yoke iron.

[0016] A magnetic isolation gasket is provided between the electromagnetic coil and the upper yoke iron; a sealing groove is provided on the contact surface between the upper yoke iron and the magnetic isolation gasket, and a rubber sealing ring is provided in the sealing groove.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention discloses a high-precision flow control proportional solenoid valve. The valve body assembly is cooperatively connected with the electromagnet assembly to form the shell and cavity of the solenoid valve. A rubber diaphragm sleeved on the air guiding connecting rod is arranged on the mating surface of the upper yoke iron and the valve seat. The outer ring of the rubber diaphragm is pressed by the upper yoke iron and the valve seat, and the inner ring is pressed by the circumferential protrusion on the air guiding connecting rod and the gasket assembly. The rubber diaphragm divides the solenoid valve cavity into two parts, namely the upper cavity where the moving armature assembly is located and the lower cavity where the gasket assembly is located. The lower cavity is communicated with the air outlet channel on the valve seat, and the upper cavity is communicated with the air inlet channel on the plugging port through the air guiding through hole on the air guiding connecting rod and passing through the gasket assembly, forming a gas pressure compensation structure. Gas enters the upper cavity from the air inlet channel and acts on the upper surface of the rubber diaphragm close to the electromagnet assembly. A part of the generated gas pressure acts on the valve core assembly, and the other part acts on the valve seat. The component of the gas pressure acting on the valve core assembly is used as a compensation force to enhance the sealing effect of the valve core assembly.

[0019] Further, in the present invention, a diaphragm bottom ring and a diaphragm top ring are respectively arranged above and below the outer ring of the rubber diaphragm. The difference between the inner diameter and the outer diameter of the diaphragm bottom ring is greater than the difference between the inner diameter and the outer diameter of the diaphragm top ring, which is used to increase the component force of the gas pressure acting on the valve core assembly and further enhance the pressure resistance performance of the proportional solenoid valve.

[0020] Further, a protruding first step surface of the gasket assembly is provided on the contact surface between the gasket assembly and the inner ring of the rubber diaphragm; a protruding second step surface of the valve seat is provided on the contact surface between the valve seat and the outer ring of the rubber diaphragm, which can enhance the sealing effect of the pressing parts of the inner and outer rings of the rubber diaphragm.

[0021] Further, the rubber diaphragm has a cloth or fiber interlayer with a warp and weft distribution in the thickness direction, which ensures the sealing effect and thickness of the rubber diaphragm while improving the pressure resistance ability and service life of the rubber diaphragm.

[0022] Further, hysteresis is the main index reflecting the control accuracy of the proportional solenoid valve, which refers to the ratio of the difference in the outlet flow rate of the proportional solenoid valve at the same electrical signal to the rated flow rate during the opening and closing processes. When designing the solenoid valve, the hysteresis of the proportional solenoid valve can be reduced by reducing the magnetic hysteresis effect of the electromagnet and the friction of the valve core movement; in the present invention, the suction surface of the moving armature is a complex curved surface in the shape of an umbrella formed by connecting a spherical surface and multiple conical surfaces. While ensuring the electromagnetic suction force of the proportional solenoid valve, it reduces the influence of the magnetic hysteresis effect of the electromagnet on the hysteresis performance of the proportional solenoid valve; at the same time, the complex curved surface in the shape of an umbrella of the moving armature also forms a similar "umbrella top" structure for the contact surface between the moving armature and the gas in the upper cavity, making the downward pressure generated by the gas evenly distributed on the contact surface of the moving armature, with an automatic centering effect, and reducing the influence of the valve core movement friction on the hysteresis performance of the proportional solenoid valve.

[0023] Furthermore, under the same working pressure, within a certain valve opening range, the outlet flow rate of the proportional solenoid valve is directly proportional to the valve opening. Among them, the proportionality coefficient K is related to the design structure of the flow channel. Generally, the smaller the flow resistance of the flow channel structure, the larger the proportionality coefficient K, the smaller the eddy current generated by the flow channel, and the more stable the control. In the present invention, a conical hole is provided at the air inlet of the plugging port, and a complex curved surface with a special structure is provided at the transition port between the air inlet channel and the air outlet channel, effectively reducing the flow resistance and eddy current generation of the gas in the proportional solenoid valve, and improving the control accuracy and stability of the proportional solenoid valve.

[0024] Furthermore, a sealing groove for installing a rubber sealing ring is provided on the contact surface between the upper yoke and the magnetic isolation gasket to prevent external leakage of the solenoid valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0026] Figure 1 It is a schematic cross-sectional structure diagram of a high-precision flow control proportional solenoid valve in the present invention;

[0027] Figure 2 It is a schematic structural diagram of the moving armature of a high-precision flow control proportional solenoid valve in the present invention;

[0028] Figure 3 It is a schematic diagram of the magnetic induction line distribution between the suction surface of the moving armature and the electromagnet assembly of a high-precision flow control proportional solenoid valve in the present invention;

[0029] Figure 4 It is a schematic diagram of the air pressure distribution on the gas contact surface of the moving armature of a high-precision flow control proportional solenoid valve in the present invention;

[0030] Figure 5 It is a schematic structural diagram of the plugging port of a high-precision flow control proportional solenoid valve in the present invention;

[0031] Figure 6 It is a schematic diagram of the partial structure of the inner ring assembly of the rubber diaphragm of a high-precision flow control proportional solenoid valve in the present invention;

[0032] Figure 7 It is a schematic diagram of the partial structure of the outer ring assembly of the rubber diaphragm of a high-precision flow control proportional solenoid valve in the present invention;

[0033] Figure 8It is a schematic diagram of the partial structure of the assembly of the rubber sealing ring of the high-precision flow control proportional solenoid valve in the present invention;

[0034] Figure 9 It is a comparison diagram of the outlet flow and input electrical signal curves of the high-precision flow control proportional solenoid valve in the present invention using an umbrella-top type moving armature and a solenoid valve using a common inverted conical moving armature;

[0035] Figure 10 It is a comparison diagram of the outlet flow and input electrical signal curves when the ratio of the inner arc surface of the curved surface of the sealing port of the high-precision flow control proportional solenoid valve in the present invention to the wall thickness of the sealing port is different.

[0036] Wherein: 1 - electronic potting compound; 2 - lower yoke; 3 - electromagnetic coil; 4 - magnetic isolation gasket; 5 - rubber sealing ring; 6 - upper yoke; 7 - valve seat; 8 - valve seat sealing ring; 9 - sealing port; 10 - sealing port sealing ring; 11 - air inlet channel; 12 - air outlet channel; 13 - gasket assembly; 14 - lower cavity; 15 - diaphragm bottom ring; 16 - rubber diaphragm; 17 - diaphragm top ring; 18 - air guiding connecting rod; 19 - leaf spring; 20 - air guiding through hole; 21 - moving armature; 22 - upper cavity; 23 - coil skeleton; 24 - power supply lead-out wire; 25 - annular space; 131 - first step surface of the gasket assembly; 132 - gasket; 181 - first step surface of the air guiding connecting rod; 201 - annular groove; 202 - stepped shaft; 211 - attracting surface; 212 - gas contact surface; 213 - spherical surface; 214 - first conical surface; 215 - second conical surface; 231 - stepped hole; 601 - first step surface of the upper yoke; 602 - second step surface of the upper yoke; 603 - sealing groove of the upper yoke; 701 - first step surface of the valve seat; 702 - second step surface of the valve seat; 901 - conical hole; 902 - complex curved surface. Detailed implementation manners

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0039] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0040] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the product of the invention is usually placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation on the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0041] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and it does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0042] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if terms such as "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0043] The following further describes the present invention in detail with reference to the figures:

[0044] See Figure 1 , the embodiments of the present invention disclose a high-precision flow control proportional solenoid valve, which includes a valve body assembly, an electromagnet assembly and a spool assembly. The valve body assembly includes a valve seat 7 and a plugging port 9. The plugging port 9 is located at the central position of the valve seat 7. An air inlet channel 11 is axially provided in the plugging port 9 for gas to flow in. The valve seat 7 is centered on the plugging port 9 and is provided with a plurality of uniformly distributed air outlet channels 12 for gas to flow out;

[0045] The electromagnet assembly includes an upper yoke 6, a lower yoke 2 and an electromagnetic coil 3. An annular groove 201 is opened inside the lower yoke 2, and the electromagnetic coil 3 is embedded inside the annular groove 201. The lower yoke 2 is connected to the upper yoke 6 by interference fit to form a complete magnetic circuit. After the electromagnetic coil is energized, an electromagnetic suction force is generated to drive the spool assembly to approach; a groove for filling electronic potting glue 1 is provided at the other end of the lower yoke 2 where the annular groove is not opened.

[0046] The spool assembly includes a moving armature 21, a leaf spring 19, a gas guiding connecting rod 18 and a gasket assembly 13. At the other end of the suction surface of the moving armature 21, there is connected a gas guiding connecting rod 18 axially provided with a gas guiding through hole 20. The gas guiding connecting rod 18 is connected with a gasket assembly 13 provided with a gasket 132. A circumferential protrusion is provided on the gas guiding connecting rod 18. On the mating surface of the circumferential protrusion and the moving armature 21, there is a leaf spring 19 sleeved on the gas guiding connecting rod 18 for providing a sealing force towards the blocking port 9 for the spool assembly. The moving armature 21 and one end of the gas guiding connecting rod 18 press the inner ring of the leaf spring 19 through interference fit. The gasket assembly 13 is connected to the spool assembly through the other end of the gas guiding connecting rod 18 for realizing sealing. The outer ring of the leaf spring 19 is placed on the first step surface 601 of the upper yoke iron, generating deformation and providing a downward sealing force for the spool assembly;

[0047] Wherein, the valve body assembly is connected with the electromagnet assembly to form the shell and cavity of the valve. Inside the cavity, there is a rubber diaphragm 16. The outer ring of the rubber diaphragm 16 is jointly pressed by a valve seat 7, a diaphragm bottom ring 15 placed on the first step surface 701 of the valve seat, an upper yoke iron 6 and a diaphragm top ring 17 placed on the second step surface 602 of the upper yoke iron. The inner ring of the rubber diaphragm 16 is jointly pressed by the gasket assembly 13 and the first step surface 181 of the gas guiding connecting rod, dividing the cavity into two parts, a lower cavity 14 and an upper cavity 22. The lower cavity 14 is directly communicated with the air outlet channel 12. The upper cavity 22 is communicated with the air inlet channel 11 through the gas guiding through hole 20 on the gas guiding connecting rod 18 and passing through the gasket assembly 13, forming a gas pressure compensation structure. Gas enters the upper cavity 22 from the air inlet channel 11, acting on the upper surface of the rubber diaphragm 16. A part of the generated gas pressure acts on the spool assembly, and the other part acts on the valve seat 7. The component force of the gas pressure acting on the spool assembly is used as a compensation force to enhance the sealing effect of the spool assembly;

[0048] The inner hole of the coil bobbin 23 of the electromagnetic coil 3 is provided with a stepped hole 231, and the central axis of the lower yoke iron 2 is provided with a stepped shaft 202. The stepped hole 231 and the stepped shaft 202 are in interference fit to ensure the installation coaxiality and non - wobbling of the electromagnetic coil 3;

[0049] See Figure 2 、 Figure 3 and Figure 4, the attracting surface 211 of the movable armature 21 close to the electromagnet assembly is a structure similar to an "umbrella top". The attracting surface 211 is a spherical surface, or a multi-segment surface formed by connecting multiple conical surfaces, or a complex surface formed by connecting multiple conical surfaces and a spherical surface. The purpose is to ensure the suction effect of the electromagnet assembly while reducing the influence of the magnetic hysteresis effect of the electromagnet on the hysteresis performance of the proportional solenoid valve; the contact surface 212 between the movable armature 21 and the gas in the lower cavity 22 is umbrella-shaped, and the contact surface 212 is a spherical surface, or a multi-segment surface formed by connecting multiple conical surfaces, or a complex surface formed by connecting multiple conical surfaces and a spherical surface, so that the downward pressure generated by the gas is evenly distributed on the contact surface 212 between the movable armature 21 and the gas, with an automatic centering effect, reducing the influence of the valve core movement friction on the hysteresis performance of the proportional solenoid valve; Hysteresis is the main index reflecting the control accuracy of the proportional solenoid valve, which refers to the ratio of the difference in the outlet flow rate at the same electrical signal to the rated flow rate during the opening and closing processes of the proportional solenoid valve. When designing the solenoid valve, the hysteresis of the proportional solenoid valve can be reduced by reducing the magnetic hysteresis effect of the electromagnet and the valve core movement friction; in the present invention, the attracting surface of the movable armature is a complex umbrella-shaped surface formed by connecting a spherical surface and multiple conical surfaces, which reduces the influence of the magnetic hysteresis effect of the electromagnet on the hysteresis performance of the proportional solenoid valve while ensuring the electromagnetic attraction of the proportional solenoid valve; at the same time, the umbrella-shaped complex surface of the movable armature makes the contact surface between the movable armature and the gas in the lower cavity also form a structure similar to an "umbrella top", so that the downward pressure generated by the gas is evenly distributed on the contact surface of the movable armature, with an automatic centering effect, reducing the influence of the valve core movement friction on the hysteresis performance of the proportional solenoid valve.

[0050] See Figure 5, a conical hole 901 is provided at the air inlet passage 11 of the plugging port 9. A complex curved surface 902 with a special structure is provided at the transition part between the air inlet passage 11 and the air outlet passage 12. The complex curved surface is successively tangent-connected by an inner arc surface with a radius R1, a plane with a width S, and an outer arc surface with a radius R2. R1 is greater than R2. The curved surface 902 contacts the rubber gasket 131 of the gasket assembly 13 to form a sealing structure. When designing the curved surface 902 for different task requirements, there are relevant design requirements for some basic dimensions and ratios of the inner arc surface, plane, and outer arc surface of the curved surface 902. The wall thickness of the plugging port 9 is T, and it is determined by the following method: R1 / R2 > 1, R1 / T = 0.55 - 0.7. Appropriately increasing the ratio of R1 / T can improve the proportional coefficient of the outlet flow rate of the proportional solenoid valve to the valve opening; S / T = 0.03 - 0.14. Appropriately increasing the ratio of S / T can improve the service life of the rubber gasket of the gasket assembly 13 while ensuring the sealing effect. Under the same working pressure and within a certain valve opening range, the outlet flow rate of the proportional solenoid valve is directly proportional to the valve opening. Among them, the proportional coefficient K is related to the design structure of the flow channel. Usually, the smaller the flow resistance of the flow channel structure, the larger the proportional coefficient K, and the smaller the eddy current generated by the flow channel, the more stable the control. In the plugging port of the present invention, a conical hole is provided at the air inlet passage opening, and a complex curved surface with a special structure is provided at the transition opening between the air inlet passage and the air outlet passage, effectively reducing the flow resistance and eddy current generation of the gas in the proportional solenoid valve, and improving the control accuracy and stability of the proportional solenoid valve.

[0051] See Figure 6 and Figure 7 , the difference between the inner diameter and the outer diameter of the diaphragm bottom ring 15 is smaller than the difference between the inner diameter and the outer diameter of the diaphragm top ring 17, which helps to increase the component force of the gas pressure on the upper surface of the rubber diaphragm 16 acting on the spool assembly, increase the gas compensation force, and further enhance the pressure resistance performance of the proportional solenoid valve;

[0052] On the contact surface between the gasket assembly 13 and the inner circle of the rubber diaphragm 16, a protruding first step surface 131 of the gasket assembly is provided. On the contact surface between the valve seat 7 and the outer circle of the rubber diaphragm 16, a protruding second step surface 702 of the valve seat is provided to enhance the sealing effect of the pressing parts of the inner and outer circles of the rubber diaphragm; the rubber diaphragm 16 has a cloth or fiber interlayer distributed in the thickness direction. The purpose is to ensure the sealing effect and thickness of the rubber diaphragm while enhancing the sealing effect and service life of the pressing parts of the inner and outer circles of the rubber diaphragm;

[0053] See Figure 8, the upper yoke 6 is provided with an upper yoke sealing groove 603. A magnetic isolation gasket 4 is provided between the lower yoke 2 and the upper yoke 6, forming a closed annular space 25. A rubber sealing ring 5 is arranged in the annular space 25 to prevent gas from flowing out of the upper cavity 22, causing external leakage of the proportional solenoid valve.

[0054] See Figure 9 , the closer the curve between the flow rate lift and the flow rate drop is, the smaller the hysteresis of the solenoid valve. It can be clearly seen from the figure that after adopting the umbrella-top type moving armature structure in the present invention, the hysteresis of the proportional solenoid valve is significantly reduced.

[0055] See Figure 10 , it can be clearly seen from the figure that for a solenoid valve with a larger R1 / T ratio, the proportional coefficient between the outlet flow rate and the input electrical signal is larger.

[0056] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-precision flow control proportional solenoid valve, characterized in that, It includes a spool assembly, an electromagnet assembly, and a valve body assembly; the valve body assembly includes a valve seat (7) and a blocking port (9); the electromagnet assembly and the valve body assembly are cooperatively connected to form a solenoid valve cavity, and the spool assembly is installed inside the solenoid valve cavity; the spool assembly includes a moving armature (21); at the other end of the suction surface of the moving armature (21), there is a gas guiding link (18) axially provided with a gas guiding through hole (20), and the gas guiding link (18) is connected with a gasket assembly (13); there is a circumferential protrusion on the gas guiding link (18), and a leaf spring (19) sleeved on the gas guiding link (18) is arranged on the mating surface of the circumferential protrusion and the moving armature (21); the valve seat (7) is axially provided with an air outlet channel (12); the blocking port (9) is axially provided with an air inlet channel (11); when the gasket assembly (13) fits with the end face of the blocking port (9), the solenoid valve is cut off; The electromagnet assembly includes a lower yoke (2) and an upper yoke (6) which are cooperatively connected and have an electromagnetic coil (3) arranged in the middle; after the electromagnetic coil (3) is energized, it is used to provide an electromagnetic force to drive the spool assembly closer and turn on the solenoid valve; on the mating surface of the upper yoke (6) and the valve seat (7), there is a rubber diaphragm (16) sleeved on the gas guiding link (18); The inner ring of the rubber diaphragm (16) is pressed by the circumferential protrusion and the gasket assembly (13), and the outer ring of the rubber diaphragm (16) is pressed by the valve seat (7) and the upper yoke (6); The valve seat (7) is provided with a first valve seat step surface (701), and a diaphragm bottom ring (15) is arranged on the first valve seat step surface (701); on the upper yoke (6), a second upper yoke step surface (602) and a first upper yoke step surface (601) are sequentially arranged along the direction of fluid entering the solenoid valve; a diaphragm top ring (17) is arranged on the second upper yoke step surface (602); the rubber diaphragm (16) is pressed by the diaphragm bottom ring (15) and the diaphragm top ring (17); the valve seat (7) and the blocking port (9) are coaxially sleeved; the gas inlet of the air inlet channel (11) is set as a tapered hole with a decreasing inner diameter; at the transition of the air inlet channel (11) and the air outlet channel (12) on the blocking port (9), there is a curved surface (902), and the curved surface (902) is sequentially tangent-connected by an inner arc surface with a radius R1, a plane with a width S, and an outer arc surface with a radius R2, and the radius R1 is greater than the radius R2; a ring groove (201) is axially opened on the lower yoke (2), and after the ring groove is opened, a central axis is formed on the lower yoke (2), and a central axis step (202) is arranged on the central axis; the electromagnetic coil (3) is composed of a coil skeleton (23) and a coil fixed thereon; a step hole (231) which is in interference fit with the central axis step (202) is arranged on the coil skeleton (23) to ensure the installation coaxiality of the electromagnetic coil (3) and the lower yoke (2).

2. The high-precision flow control proportional solenoid valve according to claim 1, wherein The difference between the inner diameter and the outer diameter of the diaphragm bottom ring (15) is smaller than the difference between the inner diameter and the outer diameter of the diaphragm top ring (17).

3. The high-precision flow control proportional solenoid valve according to claim 1, characterized in that, On the contact surface of the gasket assembly (13) and the inner ring of the rubber diaphragm (16), a protruding first step surface (131) of the gasket assembly is provided; on the contact surface of the valve seat (7) and the outer ring of the rubber diaphragm (16), a protruding second step surface (702) of the valve seat is provided.

4. The high-precision flow control proportional solenoid valve according to claim 1, characterized in that The rubber diaphragm (16) has a cloth or fiber interlayer with warp and weft distribution in the thickness direction.

5. The high-precision flow control proportional solenoid valve according to claim 1, wherein The attracting surface (211) of the moving armature (21) is umbrella-shaped; the umbrella shape is a curved surface formed by connecting a spherical surface and a plurality of conical surfaces.

6. The high-precision flow control proportional solenoid valve according to claim 1, wherein A magnetic isolation gasket (4) is provided between the electromagnetic coil (3) and the upper yoke (6); a sealing groove (603) is provided on the contact surface of the upper yoke (6) and the magnetic isolation gasket (4), and a rubber sealing ring (5) is provided in the sealing groove (603).

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