Non-return throttling device

Abstract

The invention relates to the technical field of check valves, and discloses a non-return throttling device which comprises a valve body and a throttling orifice plate, the valve body is in threaded connection to the throttling orifice plate, a flow limiting hole is formed in the throttling orifice plate, a containing cavity is formed in the throttling orifice plate, a through hole communicated with the containing cavity is formed in the hole wall of the flow limiting hole, and the through hole is communicated with the containing cavity. A baffle is rotatably connected in the through hole, the baffle rotates in the direction from the through hole to the containing cavity, an adjusting ring is rotatably connected in the containing cavity, a containing groove allowing the baffle to be inserted is formed in the inner wall of the adjusting ring, and the inner wall of the adjusting ring can abut against the baffle for blocking the through hole. Impurities can enter the containing groove under pushing of pressure of fluid, a worker does not need to interrupt operation of equipment, the operation step that a check valve and a throttling orifice need to be disassembled is omitted, and the risk that a threaded connecting piece is loosened due to frequent disassembly is reduced.

Description

Technical Field

[0001] This application relates to the technical field of check valves, and in particular to a check valve throttling device. Background Technology

[0002] Check valves, also known as one-way valves, open and close using their own weight, springs, and the pressure generated by the flow of the medium, thus preventing the medium from flowing backward. Orifice plates are artificially installed local obstruction elements with a small flow area in industrial pipelines. They achieve functions such as flow measurement, flow restriction, or pressure reduction by generating a pressure difference. In pipelines that need to control the unidirectional flow of the medium and regulate the flow rate, check valves are generally installed in orifice plates to prevent backflow of the medium, while the orifice plate is used to throttle and reduce the pressure of the fluid.

[0003] In related technologies, a check valve throttling device includes a valve body and a throttling orifice plate. The valve body is provided with an adjustment mechanism for locking the valve disc at different tilt angles. The valve body is threadedly connected to the throttling orifice plate, and the throttling orifice plate is provided with a flow-limiting orifice for adjusting the flow rate. The diameter of the flow-limiting orifice is smaller than the inner diameter of the check valve.

[0004] Because the inner diameter of the check valve is larger than the orifice diameter of the flow restrictor, when fluid flows from the check valve to the flow restrictor, impurities in the fluid may clog the interface between the check valve and the flow restrictor, preventing the fluid from flowing smoothly. This can even lead to a decrease in system flow and abnormal pressure, forcing operators to shut down the entire equipment and frequently disassemble the check valve and orifice plate to clear impurities, causing significant inconvenience to the operators and affecting the continuity and stability of equipment operation. Summary of the Invention

[0005] To address the issue of needing to frequently disassemble the check valve and orifice plate to clear impurities from the flow-limiting orifice, this application provides a check valve throttling device.

[0006] This application provides a check valve throttling device, which adopts the following technical solution: A check valve throttling device includes a valve body and a throttling orifice plate. The valve body is threadedly connected to the throttling orifice plate. The throttling orifice plate has a flow-limiting orifice for regulating flow rate and a receiving cavity. The wall of the flow-limiting orifice has a through hole communicating with the receiving cavity. A baffle is rotatably connected inside the through hole. The baffle rotates along the direction from the through hole to the receiving cavity. An adjusting ring is rotatably connected inside the receiving cavity. The inner wall of the adjusting ring has a receiving groove for the baffle to be inserted into. The inner wall of the adjusting ring can abut against the baffle that blocks the through hole. When the receiving groove and the through hole are connected, the baffle can be inserted into the receiving groove.

[0007] By adopting the above technical solution, when impurities clog the flow-limiting orifice, the operator rotates the adjusting ring to connect the receiving groove with the through hole. At this time, the fluid can push the baffle into the receiving groove, thereby increasing the diameter of the flow-limiting orifice. The impurities can enter the receiving groove under the pressure of the fluid. The operator does not need to interrupt the operation of the equipment, eliminating the need to disassemble the check valve and the orifice plate, reducing the risk of loosening of threaded connections due to frequent disassembly, providing greater convenience for the operator to clear impurities in the flow-limiting orifice, and further ensuring the continuity and stability of the equipment operation. At the same time, by rotating the baffle along the direction from the through hole to the receiving groove, the operator can rotate the adjusting ring back after cleaning the impurities. The baffle can be reset under the drive of the inner wall of the adjusting ring. At this time, the inner wall of the adjusting ring can abut against the baffle blocking the through hole, which can prevent the baffle from rotating during use, enhancing the overall stability and operational safety of the equipment.

[0008] Optionally, the valve body has a flow hole for fluid to flow out, the adjusting ring has a connection hole communicating with the receiving groove, the connection hole can communicate with the flow hole, and the wall of the flow limiting hole has a through hole communicating with the receiving cavity; when the connection hole communicates with the flow hole, the through hole communicates with the receiving groove, the fluid can pass through the receiving groove and transport impurities to the flow limiting hole.

[0009] By adopting the above technical solution, when impurities clog the middle of the flow-limiting orifice, the operator rotates the adjusting ring to connect the connecting hole with the flow hole. At this time, the perforation and the receiving tank are connected, and the fluid in the check valve can enter the receiving tank from the flow hole through the connecting hole, and then flow from the perforation into the flow-limiting orifice. This introduces additional fluid pressure to flush out the clogged impurities. The operator can clear the clogged impurities without interrupting the operation of the equipment or disassembling any parts. At the same time, the introduced fluid can transport the impurities accumulated in the receiving tank to the flow-limiting orifice, so that the impurities in the receiving tank can be cleaned simultaneously, thereby reducing the accumulation of impurities in the equipment and further maintaining the long-term stable operation of the equipment.

[0010] Optionally, a guiding arc surface is provided on the wall of the receiving groove. The distance from the guiding arc surface to the flow limiting hole gradually decreases along the direction of the connecting hole towards the receiving groove. The guiding arc surface is used to guide the fluid to transport impurities to the flow limiting hole.

[0011] By adopting the above technical solution, the distance from the guide arc surface to the flow-limiting hole gradually decreases along the direction of the connecting hole towards the receiving tank, forming a progressive reverse flow structure. This allows the fluid to more smoothly carry out impurities along the bending direction of the guide arc surface after entering the receiving tank, thereby achieving a comprehensive and thorough flushing of the receiving tank by the fluid and improving the fluid's dirt-carrying capacity. At the same time, the smooth streamlined path effectively reduces the possibility of the fluid generating eddies or stagnating in the receiving tank, thus avoiding secondary deposition of impurities.

[0012] Optionally, a limiting block is provided on the inner wall of the receiving cavity, and a limiting ring groove is provided on the adjusting ring for the limiting block to be inserted and slid; when the limiting block abuts against one side of the limiting ring groove, the receiving groove communicates with the through hole; when the limiting block abuts against the other side of the limiting ring groove, the receiving groove communicates with the through hole.

[0013] By adopting the above technical solution, a precise rotary positioning mechanism is formed by setting a limiting block on the inner wall of the receiving cavity and setting a limiting ring groove on the adjusting ring for the limiting block to be inserted and slid. This allows the adjusting ring to rotate in two directions to achieve two different states, facilitating state switching for the operator. By rotating the adjusting ring to make the limiting block abut against the groove wall of the limiting ring groove, the operator can determine whether the receiving groove is aligned with the through hole or the perforation. The operator no longer needs to spend time aligning the groove and the hole, thereby improving the operator's operating efficiency. At the same time, it prevents the risk of misadjustment of the equipment or loosening of the connection due to excessive rotation of the adjusting ring, further enhancing the stability of the equipment.

[0014] Optionally, the throttling orifice plate has an operating hole communicating with the receiving cavity, an operating rod is rotatably connected in the operating hole, the operating rod is provided with a gear, and the adjusting ring is provided with a rack that meshes with the gear.

[0015] By adopting the above technical solution, an operating rod is rotatably connected inside the operating hole, and a rack that meshes with a gear is provided on the adjusting ring. This allows the operator to rotate the adjusting ring by rotating the operating rod. The operator does not need to find additional tools or exert effort to turn the adjusting ring directly, which provides greater convenience for the operator to rotate the adjusting ring. This allows the operator to rotate the adjusting ring more effortlessly, and at the same time, the operation is concentrated on a localized point where it is easy to apply force, avoiding the inconvenience of direct manual adjustment, and further improving the efficiency and convenience of switching states.

[0016] Optionally, the throttling orifice plate is provided with an elastic element, which is used to drive the gear to disengage from the rack; when the gear and the rack are meshed, the elastic element is in a compressed state.

[0017] By adopting the above technical solution, the gear is driven to disengage from the rack by the elastic element, so that the gear and rack are in a separated state under normal conditions. This cuts off the transmission link between the operating lever and the adjusting ring, thereby preventing accidental contact and avoiding unexpected changes in the equipment state due to accidental touch or misoperation of the operating lever. When the operator needs to operate the equipment, the operator must first press the operating lever towards the elastic element to overcome the elastic force and put the gear and rack into a pre-meshing state. Only then can the operating lever be rotated to drive the adjusting ring, further improving the reliability and safety of the equipment operation.

[0018] Optionally, the operating lever is provided with a positioning block, and the wall of the operating hole is provided with a positioning groove for the positioning block to be inserted and slidably. The wall of the positioning groove is provided with a switching groove for the positioning block to be inserted, and the switching groove extends circumferentially along the operating lever.

[0019] By adopting the above technical solution, a positioning groove is provided on the wall of the operating hole for the positioning block to be inserted and slid, so as to achieve the consistency of the initial state of the operating rod, so that the gear can stably pre-mesh with the rack, reducing the steps of aligning the gear and rack. After the operator has finished adjusting the operating rod, the operator only needs to rotate the operating rod to the approximate position. Under the drive of the elastic element, the positioning block will automatically insert into the positioning groove along the opening of the positioning groove. The operator can intuitively feel the positioning block reset, so that the gear and rack can be aligned in the next operation.

[0020] Optionally, a first slot and a second slot are respectively provided on the slot walls at both ends of the switching slot; when the positioning block is located in the first slot, the receiving slot is connected to the through hole; when the positioning block is located in the second slot, the receiving slot is connected to the through hole.

[0021] By adopting the above technical solution, a first slot and a second slot are respectively opened on the slot walls at both ends of the switching slot. When the operator rotates the operating lever to a suitable angle, the positioning block can automatically engage with the first slot or the second slot under the drive of the elastic element. The gear and rack disengage, thus cutting off the transmission link. At the same time, the limiting effect of the first slot or the second slot can lock the state of the adjusting ring. The operator does not need to keep pressing the operating lever, which provides convenience for the operator.

[0022] In summary, this application includes at least one of the following beneficial technical effects: When impurities clog the flow-limiting orifice, the operator rotates the adjusting ring to connect the receiving groove with the through hole. At this point, the fluid pushes the baffle into the receiving groove, increasing the orifice diameter. Impurities are then forced into the receiving groove by the fluid pressure. This eliminates the need to interrupt equipment operation, avoiding the need to disassemble the check valve and orifice plate, reducing the risk of loosening of threaded connections due to frequent disassembly. This greatly facilitates clearing impurities from the flow-limiting orifice and further ensures the continuity and stability of equipment operation. Simultaneously, by rotating the baffle along the direction from the through hole to the receiving groove, the operator can rotate the adjusting ring back after cleaning the impurities. The baffle resets under the drive of the inner wall of the adjusting ring, and the inner wall of the adjusting ring abuts against the baffle blocking the through hole, preventing the baffle from rotating during use and enhancing the overall stability and operational safety of the equipment.

[0023] When impurities clog the middle of the flow-limiting orifice, the operator rotates the adjusting ring to connect the connecting hole with the flow hole. At this time, the perforation and the receiving tank are connected, and the fluid in the check valve can enter the receiving tank from the flow hole through the connecting hole, and then flow from the perforation into the flow-limiting orifice. This introduces additional fluid pressure to flush out the clogged impurities. The operator can clear the clogged impurities without interrupting the operation of the equipment or disassembling any parts. At the same time, the introduced fluid can transport the impurities accumulated in the receiving tank to the flow-limiting orifice, so that the impurities in the receiving tank can be cleaned simultaneously, thereby reducing the accumulation of impurities in the equipment and further maintaining the long-term stable operation of the equipment. Attached Figure Description

[0024] Figure 1 This is a structural schematic diagram of an embodiment of this application; Figure 2 This is an embodiment of the present application. Figure 1 A partial sectional view along line AA; Figure 3 This is an exploded view of the regulating ring in an embodiment of this application; Figure 4 This is an exploded schematic diagram highlighting the perforation in an embodiment of this application; Figure 5 This is an exploded view showing the operating hole in an embodiment of this application; Figure 6 yes Figure 5 Enlarged schematic diagram of part B.

[0025] Reference numerals: 1. Valve body; 11. Flow chamber; 12. Flow hole; 2. Throttling orifice plate; 21. Flow limiting orifice; 22. Receiving chamber; 221. Limiting block; 23. Through hole; 231. Baffle; 24. Perforation; 25. Operating hole; 251. Operating rod; 252. Gear; 253. Positioning block; 254. Positioning groove; 26. Fixing groove; 27. Placement groove; 271. Elastic element; 272. Fixing plate; 28. Switching groove; 281. First slot; 282. Second slot; 3. Adjusting ring; 31. Receiving groove; 311. Guide arc surface; 32. Connecting hole; 33. Limiting ring groove; 34. Rack. Detailed Implementation

[0026] The following is in conjunction with the appendix Figures 1-6 This application will be described in further detail.

[0027] This embodiment discloses a check valve throttling device. (Refer to...) Figure 1 and Figure 2 A check valve throttling device includes a valve body 1 and a throttling orifice plate 2, wherein the valve body 1 is threadedly connected to the throttling orifice plate 2. A flow chamber 11 for fluid to pass through is provided inside the valve body 1, and a flow limiting orifice 21 communicating with the flow chamber 11 is provided on the surface of the throttling orifice plate 2 away from the valve body 1. The flow limiting orifice 21 adjusts the fluid flow rate by changing the orifice diameter.

[0028] Reference Figure 2 A receiving cavity 22 is formed on the surface of the orifice plate 2 away from the valve body 1, and the receiving cavity 22 is arranged circumferentially around the wall of the flow limiting orifice 21. Multiple through holes 23 are formed on the wall of the flow limiting orifice 21, communicating with the receiving cavity 22, and are distributed circumferentially along the flow limiting orifice 21. A baffle 231 is rotatably connected to the inner wall of the through hole 23, and the baffle 231 can rotate along the direction from the through hole 23 to the receiving cavity 22.

[0029] Reference Figure 2 An adjusting ring 3 is rotatably connected within the receiving cavity 22, and the adjusting ring 3 abuts against the outer surface of the valve body 1. A receiving groove 31 for inserting a baffle 231 is provided on the inner wall of the adjusting ring 3. Multiple receiving grooves 31 are located near the valve body 1 and are arranged in a circumferential array along the adjusting ring 3, each corresponding to a baffle 231. When the opening of the through hole 23 corresponds to the inner wall of the adjusting ring 3, the inner wall of the adjusting ring 3 can abut against the baffle 231 that blocks the through hole 23.

[0030] Reference Figure 2When the junction of the flow limiting orifice 21 and the valve body 1 is blocked by impurities, the operator rotates the adjusting ring 3 to connect the receiving groove 31 with the through hole 23. At this time, the baffle 231 can be inserted into the receiving groove 31. The fluid drives the baffle 231 to rotate towards the bottom wall of the receiving groove 31, and the diameter of the flow limiting orifice 21 is increased. Impurities can be carried into the receiving groove 31 by the fluid to clear the blockage.

[0031] Reference Figure 2 A flow hole 12 communicating with the flow cavity 11 is provided on the surface of the valve body 1 near the regulating ring 3. A connecting hole 32 is provided on the surface of the regulating ring 3 abutting against the valve body 1, and the connecting hole 32 is connected to the receiving groove 31. When the regulating ring 3 rotates to a certain angle, the connecting hole 32 can communicate with the flow hole 12, and the fluid in the valve body 1 can enter the receiving groove 31 through the flow hole 12 and the connecting hole 32. A through hole 24 communicating with the receiving cavity 22 is provided on the wall of the flow limiting hole 21, and the through hole 24 is located on the inner wall surface of the middle part of the flow limiting hole 21. When the connecting hole 32 communicates with the flow hole 12, the through hole 24 communicates with the receiving groove 31.

[0032] Reference Figure 2 When impurities clog the middle of the throttling tube, the operator rotates the adjusting ring 3 to connect the perforation 24 with the receiving tank 31. At this time, the fluid can enter the receiving tank 31 through the connected flow hole 12 and connecting hole 32, and then flow from the perforation 24 to the flow restriction hole 21 to flush out the impurities clogged in the middle of the flow restriction hole 21. At the same time, the fluid can carry out the impurities in the receiving tank 31 to clean the receiving tank 31.

[0033] Reference Figure 2 and Figure 3 A guide arc surface 311 is provided on the groove wall of the receiving groove 31 away from the connecting hole 32. The distance from the guide arc surface 311 to the connecting hole 32 gradually increases along the direction of the receiving groove 31 towards the flow limiting hole 21. The fluid can be transported more smoothly to the flow limiting hole 21 through the bending direction of the guide arc surface 311, while reducing the possibility of eddies and fluid stagnation.

[0034] Reference Figure 4 A limiting block 221 is fixedly connected to the inner wall of the receiving cavity 22. A limiting ring groove 33 is provided on the inner wall of the adjusting ring 3 for the limiting block 221 to be inserted into and slide. The limiting ring groove 33 extends circumferentially along the limiting ring. When the limiting block 221 abuts against one side of the limiting ring groove 33 along its extension direction, the receiving groove 31 communicates with the through hole 23. When the limiting block 221 abuts against the other side of the limiting ring groove 33 along its extension direction, the receiving groove 31 communicates with the through hole 24. The limiting ring groove 33 limits the positioning of the limiting block 221, making it easier for workers to align the receiving groove 31 with the through hole 23 or the through hole 24, while preventing excessive rotation.

[0035] Reference Figure 2 and Figure 3 An operating hole 25 communicating with the receiving cavity 22 is provided on the surface of the throttling orifice plate 2 away from the valve body 1. The operating hole 25 is parallel to the flow limiting orifice 21. An operating rod 251 is slidably and rotatably connected inside the operating hole 25. A gear 252 is fixedly connected to the end face of the operating rod 251 near the valve body 1. A fixing groove 26 for the gear 252 to move is provided on the wall of the operating hole 25. A rack 34 meshing with the gear 252 is provided on the outer surface of the adjusting ring 3. Through the meshing of the gear 252 and the rack 34, the operator can rotate the operating rod 251 to drive the adjusting ring 3 to rotate.

[0036] Reference Figure 2 and Figure 3 A placement groove 27 is provided on the bottom wall of the fixing groove 26. An elastic element 271, which is a spring, is fixedly connected to the bottom wall of the placement groove 27. The elastic element 271 is used to drive the gear 252 to disengage from the rack 34. A fixing plate 272 is fixedly connected to the end face of the elastic element 271 away from the bottom wall of the fixing groove 26. The fixing plate 272 abuts against the gear 252. When the gear 252 and the rack 34 mesh, the elastic element 271 is in a deformed state. The operator needs to press the operating lever 251 in the direction closer to the elastic element 271 to achieve the meshing of the gear 252 and the rack 34.

[0037] Reference Figure 2 and Figure 5 A positioning block 253 is fixedly connected to the outer surface of the operating lever 251. A positioning groove 254 is provided on the wall of the operating hole 25 for the positioning block 253 to be inserted and slid. The positioning groove 254 extends through to the surface of the throttling orifice plate 2 in a direction away from the elastic member 271.

[0038] Reference Figure 2 and Figure 6 The positioning groove 254 has a switching groove 28 for the positioning block 253 to be inserted into. The switching groove 28 extends toward the groove walls on the opposite sides of the positioning groove 254. When the positioning block 253 abuts against the groove wall of the positioning groove 254 near the elastic member 271, the positioning block 253 can slide in the switching groove 28 along the circumference of the operating rod 251.

[0039] Reference Figure 2 and Figure 6The switching groove 28 has a first slot 281 and a second slot 282 respectively formed on the groove walls at both ends along its extension direction. Both the first slot 281 and the second slot 282 are parallel to the positioning groove 254. When the positioning block 253 slides in the switching groove 28 to the connection point of the first slot 281 or the second slot 282, the elastic element 271 can drive the positioning block 253 into the first slot 281 or the second slot 282. When the positioning block 253 is located in the first slot 281, the receiving groove 31 communicates with the through hole 23. When the positioning block 253 is located in the second slot 282, the receiving groove 31 communicates with the through hole 24.

[0040] The implementation principle of the check valve throttling device in this application embodiment is as follows: When impurities block the flow limiting orifice 21 at the junction of the flow limiting orifice 21 and the valve body 1, the operator presses the operating rod 251 toward the elastic element 271, so that the positioning block 253 enters the switching groove 28 along the positioning groove 254. At this time, the gear 252 and the rack 34 mesh with each other. The operator rotates the operating rod 251, so that the positioning block 253 slides into the first slot 281. At this time, the receiving groove 31 is connected to the through hole 23. The fluid drives the baffle 231 to rotate toward the receiving groove 31, so that the inner diameter of the flow limiting orifice 21 increases, and the fluid can carry the impurities into the receiving groove 31 to clear the blockage impurities.

[0041] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar words used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar words mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the design concept of this application should be included within the protection scope of this application.

Claims

1. A check valve throttling device, comprising a valve body (1) and a throttling orifice plate (2), wherein the valve body (1) is threadedly connected to the throttling orifice plate (2), and the throttling orifice plate (2) is provided with a flow-limiting orifice (21) for regulating the flow rate, characterized in that: The throttling orifice plate (2) has a receiving cavity (22), and the wall of the flow limiting orifice (21) has a through hole (23) communicating with the receiving cavity (22). A baffle (231) is rotatably connected in the through hole (23). The baffle (231) rotates along the direction from the through hole (23) to the receiving cavity (22). An adjusting ring (3) is rotatably connected in the receiving cavity (22). The inner wall of the adjusting ring (3) has a receiving groove (31) for the baffle (231) to be inserted. The inner wall of the adjusting ring (3) can abut against the baffle (231) that blocks the through hole (23). When the receiving groove (31) and the through hole (23) are connected, the baffle (231) can be inserted into the receiving groove (31).

2. The check valve throttling device according to claim 1, characterized in that: The valve body (1) is provided with a flow hole (12) for fluid to flow out, and the regulating ring (3) is provided with a connection hole (32) communicating with the receiving groove (31). The connection hole (32) can communicate with the flow hole (12). The wall of the flow limiting hole (21) is provided with a through hole (24) communicating with the receiving cavity (22). When the connection hole (32) is connected with the flow hole (12), the through hole (24) is connected with the receiving groove (31), and the fluid can pass through the receiving groove (31) and transport impurities to the flow limiting hole (21).

3. The check valve throttling device according to claim 1, characterized in that: The receiving groove (31) has a guide arc surface (311) on its groove wall. The distance from the guide arc surface (311) to the flow limiting hole (21) gradually decreases along the direction of the connecting hole (32) near the receiving groove (31). The guide arc surface (311) is used to guide the fluid to transport impurities to the flow limiting hole (21).

4. A check valve throttling device according to claim 2, characterized in that: The inner wall of the receiving cavity (22) is provided with a limiting block (221), and the adjusting ring (3) is provided with a limiting ring groove (33) for the limiting block (221) to be inserted and slid. When the limiting block (221) abuts against one side of the limiting ring groove (33), the receiving groove (31) communicates with the through hole (23). When the limiting block (221) abuts against the other side of the limiting ring groove (33), the receiving groove (31) communicates with the through hole (24).

5. A check valve throttling device according to claim 1, characterized in that: The throttling orifice plate (2) is provided with an operating hole (25) that communicates with the receiving cavity (22). An operating rod (251) is rotatably connected in the operating hole (25). A gear (252) is provided on the operating rod (251). A rack (34) that meshes with the gear (252) is provided on the adjusting ring (3).

6. A check valve throttling device according to claim 5, characterized in that: The throttling orifice plate (2) is provided with an elastic element (271), which is used to drive the gear (252) to disengage from the rack (34); when the gear (252) and the rack (34) mesh with each other, the elastic element (271) is in a compressed state.

7. A check valve throttling device according to claim 5, characterized in that: The operating lever (251) is provided with a positioning block (253), and the operating hole (25) has a positioning groove (254) for the positioning block (253) to be inserted and slid on the hole wall. The positioning groove (254) has a switching groove (28) for the positioning block (253) to be inserted on the groove wall. The switching groove (28) extends circumferentially along the operating lever (251).

8. A check valve throttling device according to claim 7, characterized in that: The first slot (281) and the second slot (282) are respectively provided on the slot walls at both ends of the switching slot (28); when the positioning block (253) is located in the first slot (281), the receiving slot (31) is connected to the through hole (23); when the positioning block (253) is located in the second slot (282), the receiving slot (31) is connected to the through hole (24).

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