A three-way reversing valve

Abstract

This invention discloses a three-way reversing valve, comprising a valve body with multiple external communication ports, a detachably connected upper base at the upper end of the valve body, a central flow channel within the valve body, and a valve stem that can move up and down within the central flow channel to control the opening and closing of the multiple external communication ports; a drive assembly is fixedly installed above the upper base; an upper valve seat and a lower valve seat are respectively embedded at both ends of the valve body, and both the upper and lower valve seats have sealing conical surfaces that mate with the conical surfaces at both ends of the valve stem, for forming a seal with the upper or lower valve seat when the valve stem moves up and down; an upper valve seat support is provided between the valve body and the upper valve seat; a diaphragm pressure block is provided inside the upper base; a diaphragm support is provided at the top of the valve stem; the upper valve seat support has curved protrusions, and the diaphragm pressure block has curved recesses that mate with the curved protrusions to form a curved static seal of the diaphragm. This invention has the advantages of strong sealing performance, high reliability, and convenient flow channel switching.

Description

Technical Field

[0001] This invention relates to the field of valve device technology, and specifically to a three-way directional valve. Background Technology

[0002] A three-way directional valve is a control valve widely used in fluid and gas pipeline systems to switch the flow direction of the medium. In refrigeration, air conditioning, and heat pump systems, the three-way directional valve controls the switching of the medium between different pipelines, thereby changing the system's operating mode. With the increasingly widespread use of carbon dioxide as an environmentally friendly refrigerant, especially in supercritical carbon dioxide cycle systems, higher performance requirements are being placed on three-way directional valves.

[0003] Existing three-way directional valves mainly include ball valves, needle valves, and diaphragm valves. Chinese utility model patent No. "CN203082264 U" proposes a three-way directional valve for agricultural irrigation, including a valve body and a valve core. The valve body has a first flow channel and a second flow channel at its two ends. A rubber sealing ring is mounted on the lower end of a guide post via a sealing ring fixing seat. Under the pressure of the medium in the piston chamber, the guide post drives the rubber sealing ring to set on the first or second guide sleeve, thus achieving directional switching. However, the existing technology has the following shortcomings: First, existing valve stems use rubber-based sealing rings for dynamic sealing. Under conditions of excessive pressure, high temperature, media corrosion, or external impact to the valve stem, the sealing structure is easily damaged, posing a risk of media leakage. Furthermore, existing valves using rubber-based sealing rings are susceptible to swelling under high temperature and pressure supercritical carbon dioxide environments. This swelling causes the sealing ring to expand in volume, decrease in hardness, and drastically deteriorate its sealing performance, ultimately leading to seal failure and media leakage.

[0004] Secondly, the existing diaphragm valves are single-pass structures. To achieve the three-way switching function, two independent drive units need to be configured to form a valve group, which leads to a complex system structure, increased cost, and larger space occupation.

[0005] Third, existing ball valves require a large torque to drive the ball to rotate, resulting in an excessively large drive device. Furthermore, the sealing of ball valves depends on the precise fit between the ball and the valve seat. The valve seat material is easily corroded in a high-pressure carbon dioxide environment, and even slight corrosion can lead to seal failure and media leakage. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a three-way reversing valve with simple structure, strong sealing performance, high reliability and convenient flow channel switching.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A three-way reversing valve includes a valve body with multiple external communication ports. The upper end of the valve body has a detachably connected upper base. The valve body has a central flow channel, and a valve stem that can move up and down within the central flow channel controls the opening and closing of the multiple external communication ports. A drive assembly is fixedly installed above the upper base, abutting against the output end of the drive assembly to drive the valve stem downwards. Upper valve seats and lower valve seats are respectively embedded at both ends of the valve body, and both the upper and lower valve seats have connections to the two ends of the valve stem. A sealing cone surface with a conical fit is used to form a seal with the upper or lower valve seat when the valve stem moves up and down; an upper valve seat support is provided between the valve body and the upper valve seat; a diaphragm pressure block is provided inside the upper base to clamp and press the edge of the diaphragm with the upper valve seat support; a diaphragm support is provided at the top of the valve stem to support the deformation of the diaphragm center to push the valve stem; the upper valve seat support has a curved protrusion, and the diaphragm pressure block has a curved recess that matches the curved protrusion to form a curved static seal of the diaphragm.

[0008] As a further improvement to the above technical solution: The diaphragm, upper valve seat, lower valve seat, and diaphragm support are all made of non-rubber polymer materials.

[0009] The lower end of the valve body is provided with a detachable lower base, and the lower base is provided with a reset component that abuts against the valve stem to drive the valve stem to move upward to switch the flow channel.

[0010] The plurality of external communication interfaces include a medium inlet, a first medium outlet, a second medium outlet, and a sensor interface. When the driving assembly drives the valve stem to move down to contact the lower valve seat, the first medium outlet opens and the second medium outlet closes. When the reset assembly drives the valve stem to move up to contact the upper valve seat, the first medium outlet closes and the second medium outlet opens.

[0011] The reset assembly includes a reset spring, a spring pad, and a valve stem connector. The spring pad is fixed to the bottom of the valve stem via the valve stem connector. The reset spring is sleeved on the valve stem connector, with one end abutting against the spring pad and the other end abutting against the inner cavity of the lower base, and is used to drive the valve stem to move upward to the initial position when the drive assembly is closed.

[0012] A lower valve seat support is provided between the lower valve seat and the valve body. Both the upper and lower valve seat supports are fitted with guide sleeves that are clearance-fitted with the valve stem for radial positioning of the valve stem.

[0013] A sealing ring is provided between the valve body and the upper valve seat base and the lower valve seat base, and the sealing ring is also provided between the lower base and the lower valve seat base.

[0014] Both the upper and lower valve seat supports are provided with through holes that communicate with the outside to balance the internal pressure.

[0015] The drive assembly includes a cylinder body, a cylinder piston, and a button. The cylinder piston is vertically movable and located within the cylinder body, with the button connected to the bottom of the cylinder piston and abutting against the center of the diaphragm. The top of the cylinder body has a drive air inlet for supplying air into the cylinder body, causing the cylinder piston to move the button downwards, thereby acting on the valve stem at the bottom of the diaphragm to move downwards.

[0016] The cylinder piston and the top of the cylinder body are provided with buffer pads, and the cylinder body is provided with wear-resistant rings and cylinder sealing rings on its periphery.

[0017] Compared with the prior art, the advantages of the present invention are as follows: Firstly, this invention discloses a three-way reversing valve that achieves a curved surface static seal by clamping and pressing the diaphragm edge with a diaphragm pressure block and an upper valve seat support. The sealing surface does not experience friction or slippage during valve operation, fundamentally eliminating the risk of media leakage due to wear, pressure shock, or external impact in existing dynamic seals. Furthermore, the combination of curved protrusions and concave surfaces causes the diaphragm to bend and deform under pressure, extending the leakage path and creating a higher local sealing pressure at the top of the curved surface, maintaining reliable sealing performance even under high-pressure conditions. This significantly improves the sealing performance and applicability of the device.

[0018] Secondly, the present invention discloses a three-way reversing valve, which drives the valve stem to move up and down in the valve body to quickly switch the flow channel by setting a driving component. The valve stem forms a conical seal with the upper valve seat and the lower valve seat, which can also ensure the sealing of the valve when the valve stem is in action, and prevent the medium from leaking inside the valve body, thus greatly ensuring the accuracy and reliability of the flow channel switching.

[0019] Thirdly, the three-way directional valve disclosed in this invention uses non-rubber polymer materials to make the diaphragm, upper valve seat, lower valve seat, and diaphragm support, solving the problem of swelling and failure of existing rubber seals in high-temperature, high-pressure, supercritical carbon dioxide environments. This significantly improves the long-term sealing reliability and service life of the directional valve under harsh operating conditions. Furthermore, the non-rubber polymer material itself has good self-lubricating and wear-resistant properties, greatly reducing the frictional resistance of the conical sealing fit between the valve stem and the upper and lower valve seats, and significantly improving the directional valve switching response speed.

[0020] Fourth, the three-way directional valve disclosed in this invention enables automatic return of the valve stem by setting a reset component in the lower base, eliminating the need for a second drive unit above the valve body. This allows the three-way directional valve to complete bidirectional flow channel switching with only one drive component, greatly simplifying the directional valve structure, reducing the number of drive units, and significantly reducing the drive footprint. Furthermore, the detachable structure of the lower base facilitates on-site maintenance and replacement of vulnerable parts.

[0021] Fifth, this invention discloses a three-way reversing valve that, through the unidirectional driving cooperation of the drive component and the reset component, achieves flexible flow path switching between the medium inlet and the first and second medium outlets. By setting a sensor interface, temperature or pressure sensors can be directly integrated and installed on the valve body, eliminating the need for a separate sensor mounting connector on the external pipeline, saving pipeline space, simplifying system layout, and greatly improving assembly efficiency.

[0022] Sixth, this invention discloses a three-way directional valve that uses a return spring as the reset power source. This design is simple in structure, low in cost, and has a fast response speed, achieving automatic valve stem return without the need for an additional drive source. The valve stem connector plays a radial guiding role throughout the compression and release process of the return spring, further improving the stability and reliability of the device.

[0023] Seventh, this invention discloses a three-way directional valve that uses a guide sleeve to linearly guide and constrain the valve stem during its up-and-down movement, radially restricting the stem and preventing it from tilting or shifting due to off-center loading. Furthermore, the guide sleeve isolates the valve stem from direct metal-to-metal friction with the upper and lower valve seat bases, preventing metal debris from contaminating the working medium and significantly protecting the system's cleanliness.

[0024] Eighth, the present invention discloses a three-way reversing valve, which achieves double external leakage protection at the upper part by setting a sealing ring between the valve body and the upper valve seat base, in cooperation with the diaphragm. It also achieves double external leakage protection at the lower part by setting sealing rings between the lower valve seat base and the valve body and the lower base, which greatly improves the sealing performance and reliability of the device.

[0025] The ninth invention discloses a three-way reversing valve, which effectively eliminates the interference of pressure buildup in the sealed chamber on the normal opening and closing action of the valve stem by opening through holes on the upper valve seat and the lower valve seat, ensuring that the drive component only needs to overcome the spring force and the medium pressure to smoothly drive the valve stem, thus ensuring the stability and reliability of the reversing action.

[0026] The tenth invention discloses a three-way reversing valve, which is pneumatically driven by a cylinder body, cylinder piston, button, and drive inlet. Only one drive inlet is needed to complete the reversing action, resulting in a simple air circuit connection and fast response. By placing the button between the cylinder piston and the diaphragm, a buffer protection function is provided, preventing the cylinder piston from directly impacting the center area of ​​the diaphragm, effectively extending the diaphragm's service life. Attached Figure Description

[0027] Figure 1 This is a three-dimensional structural diagram of a three-way reversing valve according to the present invention.

[0028] Figure 2 This is a schematic diagram of the radial cross-sectional structure of a three-way reversing valve according to the present invention.

[0029] Figure 3 For the present invention Figure 2 An enlarged structural diagram of point A.

[0030] Figure 4 This is a radial cross-sectional view of a three-way reversing valve according to the present invention.

[0031] Figure 5 This is a schematic diagram of the circumferential cross-sectional structure of the valve body of the present invention.

[0032] The labels in the diagram represent: 1. Valve body; 11. Central flow channel; 12. Valve stem; 13. Medium inlet; 14. First medium outlet; 15. Second medium outlet; 16. Sensor interface; 2. Upper base; 21. Upper valve seat; 211. Upper valve seat support; 212. Curved protrusion; 3. Diaphragm pressure block; 31. Curved recess; 4. Drive assembly; 41. Cylinder body; 42. Cylinder piston; 43. Button; 44. Drive air inlet; 45. Buffer pad; 46. Wear ring; 47. Cylinder sealing ring; 5. Diaphragm; 51. Diaphragm support; 6. Lower base; 61. Lower valve seat; 611. Lower valve seat support; 7. Reset assembly; 71. Reset spring; 72. Spring pad; 73. Valve stem connector; 8. Guide sleeve; 9. Sealing ring. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to 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 of this application.

[0035] 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 one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0037] like Figures 1 to 5 As shown, the three-way reversing valve of this embodiment includes a valve body 1 with multiple external communication ports. The upper end of the valve body 1 is provided with a detachably connected upper base 2. The valve body 1 has a central flow channel 11, and a valve stem 12 that can move up and down within the central flow channel 11 to control the opening and closing of the multiple external communication ports. A drive assembly 4 (e.g., a drive cylinder, drive motor, etc.) is fixedly installed above the upper base 2 to abut against the output end of the drive assembly 4 to drive the valve stem 12 downwards. Upper valve seats 21 and lower valve seats 61 are respectively embedded at both ends of the valve body 1. Both upper valve seats 21 and lower valve seats 61 are provided with sealing conical surfaces that cooperate with the conical surfaces at both ends of the valve stem 12 (e.g., sealing conical surfaces). Figure 4 As shown at point B), it is used to form a seal with the upper valve seat 21 or the lower valve seat 61 when the valve stem 12 moves up and down; an upper valve seat support 211 is provided between the valve body 1 and the upper valve seat 21; a diaphragm pressure block 3 is provided in the upper base 2, which is used to clamp and press the edge of the diaphragm 5 with the upper valve seat support 211; a diaphragm support 51 is provided at the top of the valve stem 12, which is used to support the deformation of the center of the diaphragm 5 to push the valve stem 12; the upper valve seat support 211 is provided with a curved protrusion 212, and the diaphragm pressure block 3 is provided with a curved recess 31 that matches the curved protrusion 212 to make the diaphragm 5 form a curved static seal.

[0038] The specific implementation plan is as follows: In the initial state, the upper base 2 is tightened onto the upper end of the valve body 1. The resulting axial preload forces the diaphragm block 3 downwards, causing the diaphragm block 3 and the upper valve seat base 211 to clamp and press the edge of the diaphragm 5 between the diaphragm block 3 and the upper valve seat base 211. The edge of the diaphragm 5 undergoes bending deformation to form a curved static seal. At this time, the drive assembly 4 is not activated, the valve stem 12 is at the top dead center position, and the upper conical surface of the valve stem 12 presses into the sealing conical surface of the upper valve seat 21 to form a seal. The first medium outlet 14 is open, and the second medium outlet 15 is closed. When a flow channel switching is required, the drive assembly 4 is activated, pushing the uncompressed central portion of the diaphragm 5. This deforms the central area of ​​the uncompressed diaphragm 5, pushing the bottom diaphragm support 51 downwards. Under the push of the drive assembly 4, the diaphragm 5 and the diaphragm support 51 cause the valve stem 12 to move downwards along the central flow channel 11. The valve stem 12 moves downwards until its lower conical surface presses into the sealing conical surface of the lower valve seat 61, forming a seal. At this time, the first medium outlet 14 is closed and the second medium outlet 15 is opened, completing the flow channel switching. When the output end of the drive assembly 4 stops applying downward force, the valve stem 12 moves upwards to reset under external force. The valve stem 12 drives the diaphragm support 51 and the diaphragm 5 to return to their original positions until the upper conical surface of the valve stem 12 presses back into the sealing conical surface of the upper valve seat 21, forming a seal. This restores the initial state where the first medium outlet 14 is open and the second medium outlet 15 is closed.

[0039] Through the aforementioned scientific and special design, this three-way reversing valve has the following advantages: First, by clamping and pressing the edge of the diaphragm 5 with the diaphragm pressure block 3 and the upper valve seat support 211, a curved static seal is achieved. The sealing surface will not rub or slide during valve operation, fundamentally eliminating the risk of media leakage due to wear, pressure shock, or external impact in existing dynamic seals. Furthermore, the cooperation between the curved protrusion 212 and the curved recess 31 causes the diaphragm 5 to bend and deform under pressure, extending the leakage path and creating a higher local sealing pressure at the top of the curved surface, maintaining reliable sealing performance even under high-pressure conditions. This significantly improves the sealing performance and applicability of the device.

[0040] Secondly, by setting the drive assembly 4 to drive the valve stem 12 to move up and down inside the valve body 1 to quickly switch the flow channel, and the valve stem 12 forms a conical seal with the upper valve seat 21 and the lower valve seat 61, the valve's sealing performance can be guaranteed when the valve stem 12 is in action, avoiding internal leakage of the medium inside the valve body 1, and greatly ensuring the accuracy and reliability of the flow channel switching.

[0041] In this embodiment, the diaphragm 5, upper valve seat 21, lower valve seat 61, and diaphragm support 51 are all made of non-rubber polymer materials (such as polyetheretherketone). By using non-rubber polymer materials to make the diaphragm 5, upper valve seat 21, lower valve seat 61, and diaphragm support 51, the problem of swelling and failure of existing rubber seals in high-temperature, high-pressure, supercritical carbon dioxide environments is solved, greatly improving the long-term sealing reliability and service life of the reversing valve under harsh operating conditions. Furthermore, the non-rubber polymer material itself has good self-lubricating and wear-resistant properties, greatly reducing the frictional resistance of the conical sealing fit between the valve stem 12 and the upper and lower valve seats 21 and 61, and significantly improving the reversing response speed.

[0042] like Figures 1 to 5 As shown, in this embodiment, the lower end of the valve body 1 is provided with a detachable lower base 6. A reset component 7 is provided inside the lower base 6, which abuts against the valve stem 12 to drive the valve stem 12 upwards to switch the flow path. By providing the reset component 7 in the lower base 6, the valve stem 12 can automatically return to its original position, eliminating the need for a second drive device above the valve body 1. This allows the three-way directional valve to complete bidirectional flow path switching with only one drive component 4, greatly simplifying the directional structure and reducing the number of drive units, thus significantly reducing the drive footprint. Furthermore, the detachable structure of the lower base 6 facilitates on-site maintenance and replacement of vulnerable parts.

[0043] like Figure 5 As shown in the figure, the arrows represent the direction of medium flow. In this embodiment, multiple external connection interfaces include a medium inlet 13, a first medium outlet 14, a second medium outlet 15, and a sensor interface 16. When the drive assembly 4 drives the valve stem 12 to move down and contact the lower valve seat 61, the first medium outlet 14 opens and the second medium outlet 15 closes. When the reset assembly 7 drives the valve stem 12 to move up and contact the upper valve seat 21, the first medium outlet 14 closes and the second medium outlet 15 opens. Through the unidirectional drive cooperation of the drive assembly 4 and the reset assembly 7, flexible flow path switching between the medium inlet 13 and the first and second medium outlets 14 and 15 is achieved. By setting the sensor interface 16, temperature or pressure sensors can be directly integrated and installed on the valve body 1, eliminating the need for a separate sensor installation joint on the external pipeline, saving pipeline space, simplifying the system layout, and greatly improving assembly efficiency.

[0044] like Figures 2 to 4As shown, in this embodiment, the reset assembly 7 includes a reset spring 71, a spring pad 72, and a valve stem connector 73. The spring pad 72 is fixed to the bottom end of the valve stem 12 via the valve stem connector 73. The reset spring 71 is sleeved on the valve stem connector 73, with one end abutting against the spring pad 72 and the other end abutting against the inner cavity of the lower base 6. It is used to drive the valve stem 12 to move upward to the initial position when the drive assembly 4 is closed. When the drive assembly 4 is working, the valve stem 12 is pressed downward, and the spring pad 72 moves downward through the valve stem connector 73, compressing the reset spring 71 to store energy. When the drive assembly 4 is closed and the pressure is released, the elastic force stored in the reset spring 71 is released, pushing the spring pad 72 upward. The spring pad 72 transmits the force to the valve stem 12 through the valve stem connector 73, causing the valve stem 12 to move upward as a whole until the upper conical surface of the valve stem 12 presses into the sealing conical surface of the upper valve seat 21 to form a seal, and the valve returns to the initial state. By using the return spring 71 as the reset power source, the structure is simple, low-cost, and has a fast response speed, achieving automatic return of the valve stem 12 without the need for an additional drive source. The valve stem connector 73 plays a radial guiding role throughout the compression and release process of the return spring 71, further improving the stability and reliability of the device.

[0045] like Figures 2 to 4 As shown, in this embodiment, a lower valve seat support 611 is also provided between the lower valve seat 61 and the valve body 1. Guide sleeves 8, which are clearance-fitted with the valve stem 12, are embedded in both the upper valve seat support 211 and the lower valve seat support 611 for radial positioning of the valve stem 12. The upper valve seat support 211 and the lower valve seat support 611 are located at the upper and lower ends of the inner cavity of the valve body 1, respectively. The two guide sleeves 8 are respectively embedded in the central through holes of the upper valve seat support 211 and the lower valve seat support 611. The valve stem 12 passes through the central holes of the two guide sleeves 8 from top to bottom, with a clearance fit between them. By setting the guide sleeves 8 to provide linear guidance and constraint for the valve stem 12 during its up-and-down movement, the valve stem 12 is radially restricted, preventing it from tilting or shifting due to off-center load. Furthermore, the guide sleeves 8 isolate the valve stem 12 from direct metal-to-metal friction with the upper valve seat support 211 and the lower valve seat support 611, preventing metal debris from contaminating the working medium and greatly protecting the cleanliness of the system.

[0046] like Figures 2 to 4 As shown, in this embodiment, sealing rings 9 are provided between the valve body 1 and both the upper valve seat support 211 and the lower valve seat support 611, and sealing rings 9 are also provided between the lower base 6 and the lower valve seat support 611. By providing sealing rings 9 between the valve body 1 and the upper valve seat support 211, and cooperating with the diaphragm 5, double external leakage protection is achieved at the top. By providing sealing rings 9 between the lower valve seat support 611 and both the valve body 1 and the lower base 6, double external leakage protection is achieved at the bottom, greatly improving the sealing performance and reliability of the device.

[0047] like Figures 2 to 4As shown, in this embodiment, both the upper valve seat support 211 and the lower valve seat support 611 are provided with through holes communicating with the outside to balance the internal pressure. By providing through holes on the upper valve seat support 211 and the lower valve seat support 611, the interference of pressure buildup in the sealed chamber on the normal opening and closing action of the valve stem 12 is effectively eliminated, ensuring that the drive assembly 4 only needs to overcome the spring force and the medium pressure to smoothly drive the valve stem 12, thus ensuring the stability and reliability of the reversing action.

[0048] like Figures 2 to 4 As shown, in this embodiment, the drive assembly 4 includes a cylinder body 41, a cylinder piston 42, and a button 43. The cylinder piston 42 is vertically movable within the cylinder body 41, and its bottom is connected to the button 43, which abuts against the center of the diaphragm 5. The top of the cylinder body 41 has a drive air inlet 44 for supplying air into the cylinder body 41, causing the cylinder piston 42 to move the button 43 downwards, thereby acting on the valve stem 12 at the bottom of the diaphragm 5 to move downwards. Compressed gas enters the inner cavity of the cylinder body 41 through the drive air inlet 44, acting on the upper end face of the cylinder piston 42 and pushing the cylinder piston 42 downwards within the cylinder body 41. The button 43 connected to the bottom of the cylinder piston 42 moves downwards with the piston, and the lower end face of the button 43 directly abuts against and presses the upper surface of the central area of ​​the diaphragm 5, causing the diaphragm 5 to elastically indent downwards. After the center of the diaphragm 5 deforms, the diaphragm support 51 moves downwards, and the diaphragm support 51 drives the valve stem 12 to move downwards, completing the flow channel switching. When the air inlet 44 stops supplying air and exhausts pressure, the gas pressure above the cylinder piston 42 disappears, and the valve stem 12 returns to its original position under the action of the lower reset component 7. Simultaneously, the cylinder piston 42 is pushed back to its initial position via the diaphragm support 51, the diaphragm 5, and the button 43. By configuring a pneumatic drive consisting of the cylinder body 41, cylinder piston 42, button 43, and air inlet 44, only one air inlet 44 is needed to complete the reversing action, resulting in a simple air circuit connection and fast response. By placing the button 43 between the cylinder piston 42 and the diaphragm 5, a buffer protection function is provided, preventing the cylinder piston 42 from directly impacting the central area of ​​the diaphragm 5, effectively extending the service life of the diaphragm 5.

[0049] Preferably, button 43 is made of non-rubber polymer material (such as polyetheretherketone) to avoid swelling failure in a high temperature, high pressure, supercritical carbon dioxide environment, which greatly improves the reliability and service life of the device.

[0050] like Figures 2 to 4As shown, in this embodiment, a buffer pad 45 is provided on the top of the cylinder piston 42 and the cylinder body 41, and a wear-resistant ring 46 and a cylinder sealing ring 47 are provided on the periphery of the cylinder body 41. The buffer pad 45 effectively reduces the impact load when the cylinder piston 42 returns to its original position, reducing the risk of component damage. The wear-resistant ring 46 prevents direct metal-to-metal friction between the cylinder piston 42 and the cylinder body 41, improving the service life of the device. The cylinder sealing ring 47 ensures that the driving gas pressure can continuously and stably act on the upper surface of the cylinder piston 42, improving the cylinder's working efficiency and driving force stability.

[0051] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A three-way directional valve, characterized in that: The valve body (1) includes a valve body (1) with multiple external communication interfaces. The upper end of the valve body (1) has a detachably connected upper base (2). The valve body (1) has a central flow channel (11) and a valve stem (12) that can move up and down within the central flow channel (11) to control the opening and closing of the multiple external communication interfaces. A drive assembly (4) is fixedly installed above the upper base (2) to abut against the output end of the drive assembly (4) to drive the valve stem (12) downwards. An upper valve seat (21) and a lower valve seat (61) are respectively embedded at both ends of the valve body (1). Both the upper valve seat (21) and the lower valve seat (61) have sealing conical surfaces that mate with the conical surfaces at both ends of the valve stem (12), used to control the opening and closing of the multiple external communication interfaces. When the valve stem (12) moves up and down, it forms a seal with the upper valve seat (21) or the lower valve seat (61); an upper valve seat support (211) is provided between the valve body (1) and the upper valve seat (21); a diaphragm pressure block (3) is provided inside the upper base (2) for clamping and pressing the edge of the diaphragm (5) with the upper valve seat support (211); a diaphragm support (51) is provided at the top of the valve stem (12) for receiving the deformation of the center of the diaphragm (5) to push the valve stem (12); the upper valve seat support (211) is provided with a curved protrusion (212), and the diaphragm pressure block (3) is provided with a curved recess (31) that matches the curved protrusion (212) to make the diaphragm (5) form a curved static seal.

2. The three-way directional valve according to claim 1, characterized in that: The diaphragm (5), upper valve seat (21), lower valve seat (61), and diaphragm support (51) are all made of non-rubber polymer materials.

3. The three-way directional valve according to claim 1, characterized in that: The lower end of the valve body (1) is provided with a detachable lower base (6), and the lower base (6) is provided with a reset component (7) that abuts against the valve stem (12) to drive the valve stem (12) to move upward to switch the flow channel.

4. The three-way directional valve according to claim 3, characterized in that: The multiple external communication interfaces include a medium inlet (13), a first medium outlet (14), a second medium outlet (15), and a sensor interface (16). When the drive assembly (4) drives the valve stem (12) to move down to contact the lower valve seat (61), the first medium outlet (14) opens and the second medium outlet (15) closes. When the reset assembly (7) drives the valve stem (12) to move up to contact the upper valve seat (21), the first medium outlet (14) closes and the second medium outlet (15) opens.

5. The three-way directional valve according to claim 3, characterized in that: The reset assembly (7) includes a reset spring (71), a spring pad (72), and a valve stem connector (73). The spring pad (72) is fixed to the bottom of the valve stem (12) through the valve stem connector (73). The reset spring (71) is sleeved on the valve stem connector (73), with one end abutting against the spring pad (72) and the other end abutting against the inner cavity of the lower base (6), and is used to drive the valve stem (12) to move upward to the initial position when the drive assembly (4) is closed.

6. The three-way directional valve according to claim 3, characterized in that: A lower valve seat support (611) is provided between the lower valve seat (61) and the valve body (1). A guide sleeve (8) that is clearance-fitted with the valve stem (12) is embedded in both the upper valve seat support (211) and the lower valve seat support (611) for radial positioning of the valve stem (12).

7. The three-way directional valve according to claim 6, characterized in that: A sealing ring (9) is provided between the valve body (1) and the upper valve seat base (211) and the lower valve seat base (611), and the sealing ring (9) is also provided between the lower base (6) and the lower valve seat base (611).

8. The three-way directional valve according to claim 6, characterized in that: Both the upper valve seat support (211) and the lower valve seat support (611) are provided with through holes that communicate with the outside in order to balance the internal pressure.

9. The three-way directional valve according to claim 1, characterized in that: The drive assembly (4) includes a cylinder body (41), a cylinder piston (42), and a button (43). The cylinder piston (42) is vertically mounted inside the cylinder body (41) and its bottom is connected to the button (43) which abuts against the center of the diaphragm (5). The top of the cylinder body (41) has a drive air inlet (44) for passing air into the cylinder body (41) to make the cylinder piston (42) drive the button (43) to move down together, so as to act on the valve stem (12) at the bottom of the diaphragm (5) to move downward.

10. The three-way directional valve according to claim 9, characterized in that: The cylinder piston (42) and the top of the cylinder body (41) are provided with buffer pads (45), and the cylinder body (41) is provided with wear-resistant rings (46) and cylinder seals (47) on its periphery.

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