Flow control valve

Abstract

The present application relates to a flow control valve, which includes: a valve body, a valve seat portion provided therein, the valve seat portion forming a valve port; a valve core, the valve core being axially movable to open or close the valve port, a pressure equalizing passage connecting the valve port and a back pressure chamber provided in the valve core; wherein the valve core has a substantially cylindrical lower end portion, and a tapered hole formed therein, the tapered hole constituting a portion of the pressure equalizing passage, the bottom end of the tapered hole being located on the bottom plane of the lower end portion, and the ratio of the diameter of the bottom end of the tapered hole to the diameter of the lower end portion being greater than 0.88. The present application provides a tapered hole on the valve core of the flow control valve, the tapered hole constituting a portion of the pressure equalizing passage, and the bottom end of the tapered hole being located on the bottom plane of the lower end portion of the valve core. The size of the tapered hole is set so that the pressure distributed in the lower portion of the valve core is uniform to balance the fluid pressure in the back pressure chamber and the valve port.

Description

Technical Field

[0001] The present application relates to the field of fluid control, and in particular to a flow control valve. Background Art

[0002] In the field of fluid control technology, flow control valves are widely used. The valve core of the flow control valve can open or close the valve port under the drive of the actuator, thereby realizing the control of the opening and closing of the flow control valve or flow regulation.

[0003] Existing pressure-balanced flow control valves typically set the pressure-bearing area of ​​the valve core's upper portion equal to the diameter of the valve port. A pressure-equalizing passage is also provided within the valve core, which directs pressure from the lower portion (valve port side) of the valve core to the upper portion, thereby maintaining the same pressure on both sides. However, due to the complex flow characteristics of fluids, achieving adequate balance within the valve core is difficult. Summary of the Invention

[0004] In order to solve the above problems, the present application provides a flow control valve, comprising: a valve body, a valve seat portion is provided in the valve body, and a valve port is formed in the valve seat portion; a valve core, the valve core can be axially moved to open or close the valve port, and a pressure equalizing passage connecting the valve port and the back pressure chamber is provided in the valve core; wherein, the valve core has a lower end portion that is roughly cylindrical, and a conical hole is formed in the valve core, the conical hole constitutes a part of the pressure equalizing passage, the bottom end of the conical hole is located on the bottom plane of the lower end portion, and the ratio of the diameter of the bottom end of the conical hole to the diameter of the lower end portion is greater than 0.88.

[0005] Optionally, the cone angle of the tapered hole is 40° to 120°.

[0006] Optionally, the ratio of the diameter of the bottom end of the tapered hole to the diameter of the lower end portion is 0.89 to 0.97.

[0007] Optionally, the ratio of the diameter of the bottom end of the tapered hole to the diameter of the lower end portion is 0.92 to 0.96.

[0008] Optionally, a guide hole is provided in the valve body, a guide portion guided by the guide hole is provided on the valve core, a seal is provided on one of the guide hole and the guide portion, and the diameter of the guide portion is the same as the diameter of the lower end portion.

[0009] Optionally, the lower end portion further includes a transition fillet located between the outer cylindrical surface of the lower end portion and the bottom plane of the lower end portion, and the transition fillet contacts the valve seat portion to close the valve port.

[0010] Optionally, one end of the transition fillet is tangent to the outer cylindrical surface of the lower end portion, and the other end of the transition fillet is tangent to the bottom plane of the lower end portion.

[0011] Optionally, the valve seat portion includes a cylindrical valve port, a first conical portion, a second conical portion and a third conical portion which are connected in sequence and have gradually increasing diameters, wherein the first conical portion forms the seating surface of the valve core, and the angle formed by the second conical portion and the axis of the valve port is smaller than the angle formed by the third conical portion and the axis of the valve port, so as to provide different flow areas according to the opening degree of the valve core.

[0012] Optionally, a metal-to-metal hard seal is formed between the valve core and the valve seat.

[0013] Optionally, a connecting portion is provided between the pressure equalizing passage and the tapered hole, and the connecting portion is cylindrical and / or conical.

[0014] In one embodiment of the present application, a tapered hole is provided in the valve core of the flow control valve. This tapered hole forms part of the pressure-equalizing passage, with the bottom end of the tapered hole located on the bottom plane of the lower end of the valve core. The ratio of the diameter of the bottom end of the tapered hole to the diameter of the lower end of the valve core is greater than 0.88, thereby achieving uniform pressure distribution across the lower portion of the valve core, thereby balancing the fluid pressure in the backpressure chamber and at the valve port. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To facilitate understanding of the present application, the present application is described in more detail below based on exemplary embodiments and in conjunction with the accompanying drawings. The same or similar reference numerals are used in the accompanying drawings to represent the same or similar components. It should be understood that the drawings are only schematic, and the sizes and proportions of the components in the drawings are not necessarily accurate.

[0016] Figure 1 This is a schematic diagram illustrating the schematic structure of the main parts of a conventional flow control valve.

[0017] Figure 2 It is a longitudinal cross-sectional view of the closed valve state of the flow control valve provided in an embodiment of the present application.

[0018] Figure 3 yes Figure 2 Longitudinal cross-sectional view of the valve body in FIG.

[0019] Figure 4 yes Figure 2 Longitudinal cross-sectional view of the valve core in FIG. DETAILED DESCRIPTION

[0020] The following describes an embodiment of the flow control valve of the present application with reference to the accompanying drawings, and the concepts of “upper and lower” in the description correspond to the upper and lower concepts in the drawings.

[0021] like Figure 1As shown, the conventional flow control valve 1 includes a valve body 11 and a valve core 12. The valve body 11 is provided with a valve seat 111, and a valve port 112 is formed on the valve seat 111. The valve core 12 is disposed in the valve body 11 and is located within a guide portion 13. The valve core 12 can move axially along the guide portion 13 so that the valve core 12 abuts or moves away from the valve seat 111, thereby opening or closing the valve port 112 and thereby achieving control over the opening and closing of the flow control valve 1 or flow regulation. A pressure equalization passage 121 is provided within the valve core 12 to introduce fluid at the valve port 112 into the backpressure chamber 14.

[0022] However, the inventors of this application have found that when the fluid flows in from the valve port 112, due to the flow characteristics of the fluid, the pressure of the fluid on the bottom plane 122 of the lower part of the valve core 12 is not uniform. Figure 1 The fluid in the area outside the center of the valve core ( Figure 1 The fluid at point B in the figure has a higher density and a higher pressure. The center of the lower part of the valve core 12 ( Figure 1 The pressure at point A in the figure flows into the back pressure chamber 14 ( Figure 1 Therefore, the pressure in the back-pressure chamber 14 is equal to the pressure at the center of the lower portion of the valve core. However, due to the uneven pressure below the valve core, a downward pressure differential is generated between the upper and lower portions of the valve core 12, making it difficult for the valve core 12 of the flow control valve 1 to achieve sufficient balance.

[0023] In order to solve the above problems, the embodiment of the present application provides a flow control valve 2, which is a pressure balanced flow control valve. Figure 2 As shown, the flow control valve 2 may include a valve body 21 , a valve core 22 , and an actuator 23 .

[0024] Combine Figure 3 As can be clearly seen, the valve body 21 is provided with a valve seat portion 211 and a valve chamber 212. The valve seat portion 211 may be located at the lower end of the valve body 21 and may form a valve port 213. The lower end of the valve port 213 has a first mounting hole 214, and the side end of the valve chamber 212 may have a second mounting hole 215.

[0025] Continue to see Figure 2 The valve core 22 can move axially through the valve chamber 212 to abut or move away from the valve seat portion 211, thereby closing or opening the valve port 213. A pressure equalizing passage 221 is provided in the valve core 22, connecting the valve port 213 and the back pressure chamber 24. The pressure equalizing passage 221 can be located at the center of the valve core 22.

[0026] The actuator 23 may include a rotor located within a housing 231 and a stator 232 located outside the housing 231. The housing 231 and the valve body 21 form a closed chamber (not shown). The actuator 23 is used to drive the valve core 22 to move axially. When the actuator 23 drives the valve core 22 to abut the valve seat 211, the valve port 213 is closed, blocking the flow of fluid between the valve port 213 and the valve chamber 212. When the actuator 23 drives the valve core 22 away from the valve seat 212, the valve port 213 is opened, allowing fluid to flow between the valve port 213 and the valve chamber 212. The degree of opening of the valve core 22 can control the flow rate of the fluid.

[0027] Furthermore, in some embodiments, Figure 2 As shown, a first joint pipe 25 is disposed within the first mounting hole 214, and a second joint pipe 26 is disposed within the second mounting hole 215. When the first joint pipe 25 serves as the outlet pipe and the second joint pipe 26 serves as the inlet pipe, the fluid flows in a first flow direction. When the first joint pipe 25 serves as the inlet pipe and the second joint pipe 26 serves as the outlet pipe, the fluid flows in a second flow direction.

[0028] Combine Figure 4 It can be clearly seen that the valve core 22 has a generally cylindrical lower end 222 and a tapered hole 223 formed therein. The tapered hole 223 constitutes a portion of the pressure equalizing passage 221, and the bottom end of the tapered hole 223 is located on the bottom plane 224 of the lower end 222. The ratio of the diameter of the bottom end of the tapered hole 223 to the diameter of the lower end 222 is greater than 0.88. The diameter of the lower end 222 refers to the diameter of the generally cylindrical outer contour of the lower end 222.

[0029] In the embodiment of the present application, a tapered hole 223 is provided in the valve core 22 of the flow control valve. The tapered hole 223 constitutes a portion of the pressure equalizing passage 221, and its bottom end is located on the bottom plane 224 of the lower end of the valve core. The ratio of the diameter of the bottom end of the tapered hole 223 to the diameter of the lower end 222 of the valve core is greater than 0.88. This arrangement allows the pressure at the valve port 213 at the bottom of the valve core 22 to be distributed as evenly as possible, thereby balancing the fluid pressure at the back pressure chamber 24 and the valve port 213. This pressure equalization, which ensures a fully balanced upper and lower portion of the valve core 22, is most prominent in the second flow direction described above.

[0030] The embodiment of the present application does not specifically limit the opening direction and specific size of the tapered hole 223. Figure 4As shown, the opening of the tapered hole 223 faces the bottom plane 224, and the cone angle θ of the tapered hole 223 is 40° to 120. The diameter of the bottom end of the tapered hole 223 is larger than the diameter of the top end of the tapered hole. The ratio of the diameter of the bottom end of the tapered hole 223 to the diameter of the lower end portion 222 is 0.89 to 0.97. Preferably, the ratio of the diameter of the bottom end of the tapered hole 223 to the diameter of the lower end portion 222 is 0.92 to 0.96. In particular, the ratio of the diameter of the bottom end of the tapered hole 223 to the diameter of the lower end portion 222 in the embodiment of the present application is 0.95. By limiting the size of the tapered hole 223 as described above, the pressure of the fluid in the back pressure chamber 24 and the valve port 213 can be balanced as well as possible.

[0031] The present application does not specifically limit the portion other than the tapered hole 223 in the pressure equalizing passage 221. In some embodiments, the pressure equalizing passage 221 may include the tapered hole 223 and a cylindrical hole of a single diameter, and the tapered hole 223 may extend from the cylindrical hole to the bottom plane 224. In other embodiments, such as Figure 2 and Figure 4 As shown, the pressure equalizing passage 221 may include a cylindrical portion 225, a connecting portion 226, and a tapered hole 223, wherein the cylindrical portion 225, the connecting portion 226, and the tapered hole 223 are sequentially connected and gradually increase in diameter. The connecting portion 226 may be cylindrical or conical, or may be a combination of a conical and cylindrical shape. The provision of the connecting portion 226 can reduce the weight of the valve core 22 to reduce the load on the actuator 23, and can also avoid the problem of high processing difficulty caused by the length of the cylindrical hole of the pressure equalizing passage 221 being too long.

[0032] like Figure 2 As shown, in some embodiments, a guide hole 216 is provided in the valve body 21, and a guide portion 227 guided by the guide hole 216 is further provided on the valve core 22. A seal 27 is provided on one of the guide hole 216 and the guide portion 227, and the guide portion 227 can be slidably mounted in the guide hole 216 through the seal 27, and the seal 27 can isolate the back pressure chamber 24 from the valve chamber 212. The present application does not make any specific restrictions on the diameter of the guide portion 227. For example, the diameter of the guide portion 227 can be the same as the diameter of the lower end portion 222 of the valve core. By setting the diameter of the guide portion 227 to be the same as the diameter of the lower end portion 222 of the valve core, the difference in the effective area of ​​the fluid at the back pressure chamber 24 and the valve port 213 can be minimized, thereby further achieving a balance between the upper and lower parts of the valve core.

[0033] The present embodiment does not impose any specific restrictions on the structure of the guide hole 216, as long as the guide hole 216 can guide the valve core 22 to abut against or away from the valve seat portion 211 along the direction of the guide hole 216. Figure 3As shown, the guide hole 216 can be formed in the valve body 21 and integrally formed with the valve port 213. This arrangement allows the guide hole 216 to be directly formed in the valve body 21, thereby simplifying the processing method and significantly reducing processing costs. Alternatively, the guide hole 216 can be provided in a separate guide member that can be installed in the valve body 21.

[0034] The present application embodiment does not specifically limit the structure and installation position of the seal 27. In some embodiments, the seal 27 can be a sealing ring, such as an O-ring or a Y-ring, or a sealing ring coated with Teflon. Figure 2 and Figure 3 As shown, the sealing member 27 can be installed between the guide portion 227 and the guide hole 216, and the mounting groove 228 of the sealing member 27 can be provided on the guide portion 227. In other embodiments, the mounting groove 228 of the sealing member 27 can also be provided in the guide hole 216.

[0035] As can be seen from the above, the valve core 22 can move axially to pass through the valve chamber 212 so that its lower end portion 222 abuts against or moves away from the valve seat portion 211. When the lower end portion 222 contacts the valve seat portion 211, the lower end portion 222 can be sealed with the valve seat portion 211 to close the valve port 213. The embodiment of the present application does not specifically limit the structure of the lower end portion 222. In some embodiments, such as Figure 4 As shown, the lower end portion 222 includes an outer cylindrical surface 229 located at the lower end portion and a bottom plane 224 at the lower end portion. A transition fillet 230 may be provided between the bottom plane 224 and the outer cylindrical surface 229. The lower end portion 222 contacts the valve seat portion 211 via the transition fillet 230 to close the valve port 213. The cooperation between the transition fillet 230 and the valve seat portion 211 can make the effective area of ​​the fluid at the valve port 213 and the effective area of ​​the fluid at the seal 27 as close as possible. The transition fillet 230 also creates a metal-to-metal hard seal between the valve core 22 and the valve seat portion 211, eliminating the need for additional seals and simplifying the sealing structure.

[0036] The present application does not make any specific limitation on the structure of the transition fillet 230. Figure 4 As shown, one end of the transition fillet 230 is tangent to the outer cylindrical surface 229 of the lower end portion, and the other end of the transition fillet 230 is tangent to the bottom plane 224 of the lower end portion. In other words, the structure of the transition fillet 230 can always be maintained at 1 / 4 of a full circle.

[0037] Additionally, in some embodiments, Figure 4As shown, the sidewall of the valve core 22 may include an annular groove 240 disposed around the axis of the valve core 22, located between the guide portion 227 and the lower end portion 222. The provision of the annular groove 240 can reduce the weight of the valve core, thereby reducing the load on the actuator 23. It is understood that the annular groove 240 can be omitted, and the guide portion 227 can extend all the way to the lower end portion 222.

[0038] The embodiment of the present application does not specifically limit the structure of the valve seat portion 211, as long as the valve seat portion 211 and the valve core 22 cooperate to realize the opening and closing of the valve port 213. For example, the valve seat portion 211 may include a cylindrical portion and a conical portion, the cylindrical portion forming the valve port 213, and the conical portion is connected to the cylindrical portion and forms a seating surface. The conical portion may be a conical portion with a single conical angle. Such a valve seat 212 has a simple structure and is relatively easy to process. In other embodiments, such as Figure 3 As shown, the valve seat 212 can be formed by a cylindrical valve port 213 and a conical portion formed by a first conical portion 217, a second conical portion 218, and a third conical portion 219, which are sequentially connected from the cylindrical valve port 213 and have gradually increasing diameters. The first conical portion 217 forms the seating surface for the valve core 22. Arranging the conical portion as three conical portions with different cone angles can control the valve core 22 to provide different flow rates at different openings. For example, the angle formed by the second conical portion 218 and the axis of the valve port 213 can be smaller than the angle formed by the third conical portion 219 and the axis of the valve port 213, thereby providing more precise flow control at small openings.

[0039] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A flow control valve, characterized in that: include: a valve body, wherein a valve seat portion is provided in the valve body, and the valve seat portion forms a valve port; a valve core, the valve core being axially movable to open or close the valve port, and a pressure equalizing passage being provided in the valve core, communicating with the valve port and a back pressure chamber; The valve core has a substantially cylindrical lower end portion, and a tapered hole is formed in the valve core, the tapered hole constituting a portion of the pressure equalizing passage, the bottom end of the tapered hole being located on the bottom plane of the lower end portion, and the ratio of the diameter of the bottom end of the tapered hole to the diameter of the lower end portion is greater than 0.88; A guide hole is provided in the valve body, a guide portion guided by the guide hole is provided on the valve core, a sealing member is provided on one of the guide hole and the guide portion, and a diameter of the guide portion is the same as a diameter of the lower end portion.

2. The flow control valve according to claim 1, characterized in that: The cone angle of the tapered hole is 40° to 120°.

3. The flow control valve according to claim 1, characterized in that: The ratio of the diameter of the bottom end of the tapered hole to the diameter of the lower end portion is 0.89-0.

97.

4. The flow control valve according to claim 1, characterized in that: The ratio of the diameter of the bottom end of the tapered hole to the diameter of the lower end is 0.92-0.

96.

5. The flow control valve according to claim 1, characterized in that: The lower end portion further includes a transition fillet located between the outer cylindrical surface of the lower end portion and the bottom plane of the lower end portion, and the transition fillet contacts the valve seat portion to close the valve port.

6. The flow control valve according to claim 5, characterized in that: One end of the transition fillet is tangent to the outer cylindrical surface of the lower end portion, and the other end of the transition fillet is tangent to the bottom plane of the lower end portion.

7. The flow control valve according to claim 1, characterized in that: The valve seat portion includes a cylindrical valve port, a first conical portion, a second conical portion and a third conical portion which are connected in sequence and whose diameters gradually increase, wherein the first conical portion forms the seating surface of the valve core, and the angle formed between the second conical portion and the axis of the valve port is smaller than the angle formed between the third conical portion and the axis of the valve port, so as to provide different flow areas according to the opening degree of the valve core.

8. The flow control valve according to any one of claims 1 to 7, characterized in that: There is a metal-to-metal hard seal between the valve core and the valve seat.

9. The flow control valve according to any one of claims 1 to 7, characterized in that: A connecting portion is further provided between the pressure equalizing passage and the tapered hole, and the connecting portion is cylindrical and / or conical.

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