Manual operation mechanism for valve

Abstract

The invention relates to the technical field of valves, and discloses a manual operation mechanism for a valve, which comprises a flux sleeve, a plug, a connecting rod and a piston, the flux sleeve is provided with a piston cavity, the plug is fixedly mounted at the tail end of the flux sleeve, the connecting rod axially penetrates into the piston cavity, one end of the connecting rod is directly or indirectly connected with a valve core of the valve, and the other end of the connecting rod penetrates out of the plug. The piston is arranged in the piston cavity and is in axial sliding sealing fit with the piston cavity, the piston is provided with at least two shaft sections with different diameters, a working medium can act on the piston, the piston generates acting force far away from the plug in the axial direction, the connecting rod is in axial limiting fit with the piston, and the acting force far away from the plug borne by the piston can be transmitted to the connecting rod. And the opposite acting force towards the plug on the connecting rod is balanced. Compared with a traditional scheme that a spring is adopted to balance the opposite acting force borne by the connecting rod and facing a plug, mutual dynamic balance can be achieved within the range of all working conditions from low pressure to high pressure, and the effect of labor-saving operation under all working conditions is achieved.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and more specifically to a manual operating mechanism for valves. Background Technology

[0002] Solenoid valves are crucial control components in hydraulic systems. They utilize the magnetic field generated by energizing an electromagnetic coil to drive the valve core, thereby controlling the flow path, switching directions, or regulating flow. Solenoid valves are typically equipped with a manual operating mechanism for handling situations such as valve jamming, power failure, low voltage, or malfunction, ensuring system reliability.

[0003] Existing manual operating mechanisms for solenoid valves typically employ a connecting rod, with one end directly or indirectly connected to the valve core and the other end extending outward through a plug. Operators can pull the connecting rod to actuate the valve core, enabling emergency switching or opening / closing in case of valve malfunction. However, the internal fluid pressure of the solenoid valve acts on the connection between the connecting rod and the valve core, generating an outward axial thrust. This thrust increases with higher system pressure. Current solutions primarily involve using a spring to counteract the hydraulic pressure. However, to match the valve's rated operating pressure, the spring force must exceed the axial thrust on the connecting rod at maximum system pressure. This results in insufficient hydraulic pressure to counteract the spring force at low system pressures, requiring operators to overcome significant spring force to pull the connecting rod, leading to laborious and inconvenient manual operation. Summary of the Invention

[0004] The purpose of this invention is to provide a manual operating mechanism for valves, which solves the problem of laborious and inconvenient manual operation by operators under low-pressure conditions due to insufficient hydraulic pressure to counteract spring force.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a manual operating mechanism for a valve, comprising: a magnetic sleeve having a piston cavity; a plug fixedly installed at the tail end of the magnetic sleeve; a connecting rod axially passing through the piston cavity, one end of the connecting rod being directly or indirectly connected to the valve core of the valve, and the other end passing through the plug; a piston disposed in the piston cavity and axially slidingly and sealingly fitted with the piston cavity, the piston having at least two shaft segments of different diameters, enabling the working medium to act on the piston, causing the piston to generate an axial force away from the plug, and the connecting rod being axially limited in fit with the piston.

[0006] As an alternative, the piston includes a first through hole, a large-diameter section, and a small-diameter section. The connecting rod passes through the first through hole and has a gap with the first through hole. The large-diameter section is located between the plug and the small-diameter section. The piston chamber includes a first chamber section and a second chamber section arranged axially thereon. The large-diameter section slides and seals with the first chamber section, and the small-diameter section slides and seals with the second chamber section.

[0007] As an alternative, the large-diameter section divides the first cavity into a rod-type cavity and a rodless cavity. The rodless cavity has an exhaust port on its wall, and the rodless cavity communicates with the outside through the exhaust port.

[0008] As an alternative, the peripheral wall of the large-diameter section is provided with a first mounting groove, and a first sealing element is provided in the first mounting groove. The radially inner annular surface of the first sealing element abuts against the outer peripheral wall of the large-diameter section, and the radially outer annular surface of the first sealing element abuts against the cavity wall of the first cavity section. The peripheral wall of the small-diameter section is provided with a second mounting groove, and a second sealing element is provided in the second mounting groove. The radially inner annular surface of the second sealing element abuts against the outer peripheral wall of the small-diameter section, and the radially outer annular surface of the second sealing element abuts against the cavity wall of the second cavity section.

[0009] As an alternative, the plug further includes a second through hole, a third sealing element is provided between the connecting rod and the second through hole, and a fourth sealing element is provided between the plug and the magnetic sleeve.

[0010] As an optional embodiment, the piston includes a first through hole, a large-diameter section, and a small-diameter section. The small-diameter section is located between the plug and the large-diameter section. The plug has an expanding cavity. At least a portion of the small-diameter section passes through the expanding cavity and slides in a sealing fit with the cavity wall of the expanding cavity. The large-diameter section slides in a sealing fit with the cavity wall of the piston chamber. A pressure chamber is formed between the large-diameter section and the plug. The connecting rod passes through the first through hole and is sealed in a fit with the first through hole. The connecting rod has an oil passage, and the pressure chamber communicates with the oil passage. The magnetic sleeve also includes a communicating hole communicating with the piston chamber. The communicating hole is located on the side of the piston away from the plug. The connecting rod passes through the communicating hole, and a fifth sealing element is provided between the connecting rod and the communicating hole.

[0011] As an alternative, the oil passage includes an axial flow channel and a first oil passage hole. The axial flow channel forms an opening on the end face of the connecting rod away from the plug. The small diameter section is provided with a second oil passage hole. The axial flow channel communicates with the pressure chamber through the first oil passage hole and the second oil passage hole.

[0012] As an alternative, a closed cavity is formed between the end face of the piston away from the plug and the magnetic sleeve, and the cavity wall of the closed cavity is provided with a vent hole, through which the gas in the closed cavity can be discharged.

[0013] As an alternative, a sixth seal is provided between the large-diameter section and the wall of the piston chamber, a seventh seal is provided between the small-diameter section and the wall of the expansion chamber, and an eighth and a ninth seal are provided between the wall of the first through hole and the connecting rod. Along the axial direction of the connecting rod, the eighth and the ninth seals are respectively located on both sides of the first oil passage hole.

[0014] As an alternative, an elastic element is provided between the piston and the plug, with one end of the elastic element abutting the plug and the other end abutting the piston. The connecting rod has a limiting part, and the piston abuts against the limiting part under the action of the elastic element.

[0015] As an alternative, the device also includes a sleeve and a handle, wherein the sleeve is fitted onto one end of the connecting rod that extends out of the magnetic sleeve, and the end of the sleeve away from the piston is provided with a wire retaining ring to prevent the sleeve from dislodging from the connecting rod, and at least a portion of the handle is fitted onto the sleeve and fixedly connected to the sleeve.

[0016] The beneficial effects of this invention are: This invention utilizes pistons with different diameter shaft segments in the manual valve operating mechanism. The difference in area created by the different shaft diameters allows the system pressure to act on the piston, generating an axial force away from the plug. This causes the piston's end face away from the plug to abut against a limiting part. The piston's action on the limiting part then applies an axial force away from the plug to the connecting rod. This force balances the opposing axial force generated by the working medium acting directly on the connecting rod towards the plug. Since both the connecting rod and piston are driven by the same system pressure, the generated forces always change proportionally, achieving mutual balance across the entire operating range from low to high pressure, thus achieving effortless operation under all conditions. Furthermore, compared to the traditional method of using springs to balance the axial thrust on the connecting rod, the manual valve operating mechanism proposed in this invention eliminates the need to replace components for different pressure levels, improving the mechanism's versatility. Attached Figure Description

[0017] Figure 1 A cross-sectional structural schematic diagram of a first embodiment of a manual operating mechanism for a valve provided by the present invention; Figure 2 A cross-sectional structural schematic diagram of a second embodiment of a manual operating mechanism for a valve provided by the present invention; Figure 3A cross-sectional schematic diagram of the magnetic sleeve of a first embodiment of a manual operating mechanism for a valve provided by the present invention; Figure 4 A partial cross-sectional structural diagram of the connecting rod of a first embodiment of a manual operating mechanism for a valve provided by the present invention; Figure 5 A partial cross-sectional view of the connecting rod of a second embodiment of a manual operating mechanism for a valve provided by the present invention; In the picture: 1. Magnetic sleeve; 11. Piston chamber; 111. First chamber segment; 1111. Rod chamber; 1112. Rodless chamber; 112. Second cavity section; 12. Connecting hole; 2. Plug; 21. Second through hole; 22. Expanded oral cavity; 3. Piston; 31. First through hole; 32. Large diameter section; 321. First mounting groove; 33. Small diameter section; 331. Second mounting groove; 332. Second oil passage hole; 4. Connecting rod; 41. Limiting part; 42. Axial flow channel; 43. First oil passage hole; 5. Vent hole; 6. First seal; 7. Second seal; 8. Third seal; 9. Fourth seal; 10. Pressure chamber; 110. Fifth sealing element; 120. Sealed cavity; 13. Breathing hole; 14. Sixth sealing element; 15. Seventh sealing element; 16. Eighth sealing element; 17. Ninth sealing element; 18. Elastic element; 19. Sleeve; 20. Handle; 210. Wire retaining ring. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only some structures relevant to the present invention, not all structures.

[0019] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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 invention based on the specific circumstances.

[0020] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0022] Reference Figures 1-5 This invention provides a manual operating mechanism for a valve, including a magnetic sleeve 1, a plug 2, a connecting rod 4, and a piston 3. The tail end of the magnetic sleeve 1 is open, and a piston cavity 11 is formed inside it. The plug 2 is fixedly installed at the tail end of the magnetic sleeve 1. The connecting rod 4 passes axially through the piston cavity 11. One end of the connecting rod 4 is directly or indirectly connected to the valve core of the valve to drive the valve core to move, and the other end extends outward through the plug 2 to facilitate manual operation. The piston 3 is disposed in the piston cavity 11 and slides and seals with the piston cavity 11. The piston 3 has at least two shaft segments of different diameters to create an area difference in the radial direction of the piston 3, so that when the working medium acts on the piston 3, it can generate a force that moves the piston 3 axially away from the plug 2. At the same time, the end face of the connecting rod 4 near the valve core is subjected to the working medium and generates a reverse force toward the plug 2. The connecting rod 4 has a limiting part 41, and the end face of the piston 3 away from the plug 2 can abut against the limiting part 41 under the action of the working medium. The piston 3 acts on the limiting part 41, so that the connecting rod 4 receives an axial force away from the plug 2. This force can balance the reverse force generated by the working medium acting directly on the connecting rod 4 in the axial direction toward the plug 2.

[0023] Since both connecting rod 4 and piston 3 are driven by the same system pressure, the forces generated by them always change proportionally. Therefore, they can achieve dynamic balance between each other in the entire working condition range from low pressure to high pressure. Compared with the traditional solution of using springs to balance the reverse force on connecting rod 4 towards plug 2, it can achieve the effect of labor-saving operation in all working conditions, and there is no need to replace parts for different pressure levels of the system, thus improving the versatility of the mechanism.

[0024] In one embodiment, reference is made to Figure 1 , Figure 3 The piston 3 includes a first through hole 31, a large-diameter section 32, and a small-diameter section 33. The large-diameter section 32 is located between the piston 3 and the small-diameter section 33, and the diameter of the large-diameter section 32 is larger than the diameter of the small-diameter section 33. The piston cavity 11 includes a first cavity section 111 and a second cavity section 112 arranged axially. The large-diameter section 32 is axially slidingly sealed with the cavity wall of the first cavity section 111, and the small-diameter section 33 is axially slidingly sealed with the cavity wall of the second cavity section 112. Specifically, a first mounting groove 32 is formed on the peripheral sidewall of the large-diameter section 32. 1. The first sealing element 6 is fitted into the first mounting groove 321. The radially inner annular surface of the first sealing element 6 abuts against the outer peripheral wall of the large-diameter section 32, and the radially outer outer surface of the first sealing element 6 abuts against the cavity wall of the first cavity section 111. The peripheral side wall of the small-diameter section 33 is provided with a second mounting groove 331. The second sealing element is fitted into the second mounting groove 331. The radially inner annular surface of the second sealing element abuts against the outer peripheral wall of the small-diameter section 33, and the radially outer annular surface of the second sealing element abuts against the cavity wall of the second cavity section 112. The connecting rod 4 passes through the first through hole 31 and has a gap between it and the first through hole 31. The working medium can act on both ends of the piston 3 through this gap. Since the end face area of ​​the piston 3 near the plug 2 is larger than the end face area away from the plug 2, the piston 3 is subjected to a resultant force in the direction away from the plug 2, which can balance the reverse force on the connecting rod 4 towards the plug 2.

[0025] Reference Figure 1 , Figure 3The large-diameter section 32 divides the first chamber section 111 into two independent rod chambers 1111 and rodless chamber 1112. Since the large-diameter section 32 and the first chamber section 111, and the small-diameter section 33 and the second chamber section 112, are in a sliding seal fit, the rodless chamber 1112 is a closed annular cavity. During the axial reciprocating motion of the piston 3 along the piston chamber 11, the volume of the rodless chamber 1112 changes synchronously with the displacement of the piston 3. Due to the closed structure, the gas inside the cavity cannot exchange with the outside, leading to pressure fluctuations within the cavity. When the piston 3 moves towards the rod chamber 1111, the volume of the rodless chamber 1112 increases, creating a negative pressure within the cavity; conversely, when the piston 3 moves towards the rodless chamber 1112, the volume decreases, creating a positive pressure within the cavity. This pressure difference generates reverse resistance to the axial movement of the piston 3, affecting not only the smoothness of the piston 3's movement but also increasing the resistance to manual operation, resulting in difficult manual adjustment and a clunky feel. As a preferred embodiment, the rodless chamber 1112 has an exhaust port 5 on its wall, through which the rodless chamber 1112 communicates with the outside. By providing this exhaust port 5, during the axial movement of the piston 3, the gas inside the rodless chamber 1112 can be discharged or drawn in in a timely manner through the exhaust port 5, achieving pressure balance inside and outside the rodless chamber 1112, effectively eliminating the obstruction of the pressure difference on the movement of the piston 3, and ensuring that the piston 3 always maintains stable and smooth axial movement.

[0026] Furthermore, the plug 2 has a second through hole 21 along the axial direction, through which the connecting rod 4 passes, with at least a portion of the connecting rod 4 extending out of the plug 2 for easy manual operation. A third seal 8 is provided between the connecting rod 4 and the second through hole 21. The radially inner annular surface of the third seal 8 abuts against the peripheral wall of the connecting rod 4, and the radially outer annular surface of the third seal 8 abuts against the cavity wall of the second through hole 21. A fourth seal 9 is provided between the plug 2 and the magnetic sleeve 1. The radially inner annular surface of the fourth seal 9 abuts against the peripheral wall of the plug 2, and the radially outer annular surface of the fourth seal 9 abuts against the cavity wall of the piston cavity 11 of the magnetic sleeve 1. By providing the third seal 8 and the fourth seal 9, oil in the rod cavity 1111 can be prevented from leaking from the fitting gaps between the plug 2 and the connecting rod 4, and between the plug 2 and the magnetic sleeve 1.

[0027] In another implementation, refer to Figure 2 , Figure 5The piston 3 includes a first through hole 31, a large diameter section 32 and a small diameter section 33. The small diameter section 33 is located between the plug 2 and the large diameter section 32, and the diameter of the small diameter section 33 is smaller than the diameter of the large diameter section 32. The plug 2 has an opening on the side near the piston 3 and forms an eccentric cavity 22. At least a portion of the small diameter section 33 is inserted into the eccentric cavity 22 and is axially slidingly sealed with the cavity wall of the eccentric cavity 22. The large diameter section 32 is axially slidingly sealed with the cavity wall of the piston cavity 11. A closed annular pressure chamber 10 is formed between the large-diameter section 32 and the plug 2. The connecting rod 4 passes through the first through hole 31 and is sealed to the first through hole 31. The connecting rod 4 has an oil passage, which includes an axial flow channel 42 and a first oil passage hole 43 communicating with the axial flow channel 42. The axial flow channel 42 forms an opening on the end face of the connecting rod 4 away from the plug 2. The small-diameter section 33 has a second oil passage hole 332 opened radially therein. The pressure chamber 10 is connected to the axial flow channel 42 through the first oil passage hole 43 and the second oil passage hole 332. The working medium can enter the pressure chamber 10 through the axial flow channel 42, the first oil passage hole 43, and the second oil passage hole 332, and act on the annular surface at the transition between the large-diameter section 32 and the small-diameter section 33, applying a force to the piston 3 away from the plug 2, so as to balance the reverse force on the connecting rod 4 towards the plug 2.

[0028] Specifically, refer to Figure 2 The sealing method between the large-diameter section 32 and the piston cavity 11 is as follows: a sixth sealing element 14 is provided between the large-diameter section 32 and the piston cavity 11. The radially inner annular surface of the sixth sealing element 14 abuts against the peripheral wall of the large-diameter section 32, and the radially outer annular surface of the sixth sealing element 14 abuts against the cavity wall of the piston cavity 11, preventing the working medium from acting on the end face of the piston 3 away from the plug 2 through the fitting gap between the large-diameter section 32 and the piston cavity 11. The sealing method between the small-diameter section 33 and the flared cavity 22 is as follows: a seventh sealing element 15 is provided between the small-diameter section 33 and the flared cavity 22. The radially inner annular surface of the seventh sealing element 15 abuts against the peripheral wall of the large-diameter section 32, and the radially outer annular surface of the sixth sealing element 14 abuts against the cavity wall of the piston cavity 11, preventing the working medium from acting on the end face of the piston 3 away from the plug 2 through the fitting gap between the large-diameter section 32 and the piston cavity 11. The peripheral wall of the small diameter section 33 abuts against the seventh seal 15, and the radially outer annular surface of the seventh seal 15 abuts against the cavity wall of the expansion cavity 22, preventing the working medium from acting on the end face of the piston 3 near the plug 2 through the fit gap between the small diameter section 33 and the expansion cavity 22; the sealing method between the connecting rod 4 and the first through hole 31 is as follows: an eighth seal 16 and a ninth seal 17 are provided between the first through hole 31 and the connecting rod 4. Along the axial direction of the connecting rod 4, the eighth seal 16 and the ninth seal 17 are located on both sides of the first oil passage hole 43, preventing the working medium from acting on both end faces of the piston 3 through the fit gap between the connecting rod 4 and the first through hole 31.

[0029] The magnetic sleeve 1 also includes a connecting hole 12 that communicates with the piston chamber 11. The connecting hole 12 is located on the side of the piston chamber 11 away from the plug 2. The connecting rod 4 passes through the connecting hole 12, and a fifth sealing element 110 is provided between the connecting rod 4 and the wall of the connecting hole 12 to prevent the working medium from acting on the end face of the piston 3 away from the plug 2 through the gap between the connecting rod 4 and the connecting hole 12.

[0030] Reference Figure 2 A closed cavity 120 is formed between the end face of the piston 3 away from the plug 2 and the magnetic sleeve 1. Preferably, the cavity wall of the closed cavity 120 has a vent hole 13, through which the closed cavity 120 communicates with the outside. By providing this vent hole 13, during the axial movement of the piston 3, the gas inside the closed cavity 120 can be timely discharged or drawn in through the vent hole 13, achieving pressure balance inside and outside the closed cavity 120. This effectively eliminates the obstruction of the piston 3's movement due to pressure difference, ensuring that the piston 3 always maintains stable and smooth axial movement.

[0031] Reference Figure 1 , Figure 2 The manual operating mechanism for the valve provided by this invention further includes an elastic element 18, a sleeve 19, and a handle 20. The elastic element 18 is disposed between the piston 3 and the plug 2, with one end abutting against the plug 2 and the other end abutting against the piston 3. Under the elastic force of the elastic element 18, the piston 3 abuts against the limiting part 41. The sleeve 19 is sleeved on the end of the connecting rod 4 that extends out of the magnetic sleeve 1, and the end of the sleeve 19 away from the piston 3 is provided with a wire retaining ring 210 to prevent the sleeve 19 from dislodging from the connecting rod 4. At least a portion of the handle 20 is sleeved on the outside of the sleeve 19 and fixedly connected to the sleeve 19. When the solenoid valve is stuck, de-energized, under-voltage, or malfunctioning and cannot be electrically driven normally, the operator can manually pull the handle 20 to drive the sleeve 19 to move synchronously, thereby driving the connecting rod 4 to overcome the elastic force of the elastic element 18 and move in a direction away from the magnetic sleeve 1. Since the connecting rod 4 is directly or indirectly connected to the valve core, the connecting rod 4 can drive the valve core to move synchronously, realize the manual adjustment of the valve core, and ensure that the valve can still be reliably opened, closed or switched in the event of electric failure.

[0032] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A manual operating mechanism for a valve, characterized in that: include A magnetic sleeve (1) having a piston cavity (11); A plug (2) is fixedly installed at the tail end of the magnetic sleeve (1); Connecting rod (4), the connecting rod is axially inserted into the piston chamber (11), one end of the connecting rod (4) is directly or indirectly connected to the valve core of the valve, and the other end passes through the plug (2); The piston (3) is located in the piston chamber (11) and is axially slidingly sealed with the piston chamber (11). The piston (3) has at least two shaft segments of different diameters, which enable the working medium to act on the piston (3) and generate an axial force away from the plug (2). The connecting rod (4) is axially limited with the piston (3).

2. The manual operating mechanism for a valve according to claim 1, characterized in that: The piston (3) includes a first through hole (31), a large diameter section (32) and a small diameter section (33). The connecting rod (4) passes through the first through hole (31) and has a gap with the first through hole (31). The large diameter section (32) is located between the plug (2) and the small diameter section (33). The piston chamber (11) includes a first chamber section (111) and a second chamber section (112) arranged along its axial direction. The large diameter section (32) is slidably sealed with the first chamber section (111), and the small diameter section (33) is slidably sealed with the second chamber section (112).

3. The manual operating mechanism for a valve according to claim 2, characterized in that: The large-diameter section (32) divides the first cavity section (111) into a rod cavity (1111) and a rodless cavity (1112). The rodless cavity (1112) has an exhaust hole (5) on its cavity wall, and the rodless cavity (1112) communicates with the outside through the exhaust hole (5).

4. The manual operating mechanism for a valve according to claim 3, characterized in that: The large-diameter section (32) has a first mounting groove (321) on its peripheral sidewall. A first sealing element (6) is provided in the first mounting groove (321). The radially inner annular surface of the first sealing element (6) abuts against the outer peripheral wall of the large-diameter section (32), and the radially outer annular surface of the first sealing element (6) abuts against the cavity wall of the first cavity section (111). The small-diameter section (33) has a second mounting groove (331) on its peripheral sidewall. A second sealing element (7) is provided in the second mounting groove (331). The radially inner annular surface of the second sealing element (7) abuts against the outer peripheral wall of the small-diameter section (33), and the radially outer annular surface of the second sealing element (7) abuts against the cavity wall of the second cavity section (112).

5. A manual operating mechanism for a valve according to claim 4, characterized in that: The plug (2) also includes a second through hole (21), a third sealing element (8) is provided between the connecting rod (4) and the second through hole (21), and a fourth sealing element (9) is provided between the plug (2) and the magnetic sleeve (1).

6. The manual operating mechanism for a valve according to claim 1, characterized in that: The piston (3) includes a first through hole (31), a large diameter section (32) and a small diameter section (33). The small diameter section (33) is located between the plug (2) and the large diameter section (32). The plug (2) has an enlarged cavity (22). At least a portion of the small diameter section (33) is inserted into the enlarged cavity (22) and slides and seals with the cavity wall of the enlarged cavity (22). The large diameter section (32) slides and seals with the cavity wall of the piston cavity (11). A pressure cavity (10) is formed between the large diameter section (32) and the plug (2). The connecting rod (4) passes through the first through hole (31) and is sealed to the first through hole (31). The connecting rod (4) has an oil passage, and the pressure chamber (10) is connected to the oil passage. The magnetic sleeve (1) also includes a connecting hole (12) communicating with the piston chamber (11). The connecting hole (12) is located on the side of the piston (3) away from the plug (2). The connecting rod (4) passes through the connecting hole (12) and a fifth sealing element (110) is provided between the connecting rod (4) and the hole wall of the connecting hole (12).

7. A manual operating mechanism for a valve according to claim 6, characterized in that: The oil passage includes an axial flow channel (42) and a first oil passage hole (43). The axial flow channel (42) forms an opening on the end face of the connecting rod (4) away from the plug (2). The small diameter section (33) is provided with a second oil passage hole (332). The axial flow channel (42) is connected to the pressure chamber (10) through the first oil passage hole (43) and the second oil passage hole (332).

8. A manual operating mechanism for a valve according to claim 7, characterized in that: A closed cavity (120) is formed between the end face of the piston (3) away from the plug (2) and the magnetic sleeve (1). The cavity wall of the closed cavity (120) is provided with a vent hole (13), and the gas in the closed cavity (120) can be discharged through the vent hole (13).

9. A manual operating mechanism for a valve according to claim 8, characterized in that: A sixth seal (14) is provided between the large-diameter section (32) and the cavity wall of the piston chamber (11), a seventh seal (15) is provided between the small-diameter section (33) and the cavity wall of the expansion chamber (22), and an eighth seal (16) and a ninth seal (17) are provided between the hole wall of the first through hole (31) and the connecting rod (4). Along the axial direction of the connecting rod (4), the eighth seal (16) and the ninth seal (17) are located on both sides of the first oil passage hole (43).

10. A manual operating mechanism for a valve according to claim 2 or 6, characterized in that: An elastic element (18) is provided between the piston (3) and the plug (2). One end of the elastic element (18) abuts against the plug (2) and the other end abuts against the piston (3). The connecting rod has a limiting part (41). The piston (3) abuts against the limiting part (41) under the action of the elastic element (18).

11. A manual operating mechanism for a valve according to claim 10, characterized in that: It also includes a sleeve (19) and a handle (20). The sleeve (19) is fitted onto one end of the connecting rod (4) that extends out of the magnetic sleeve (1). The end of the sleeve (19) away from the piston (3) is provided with a wire retaining ring (210) to prevent the sleeve (19) from coming off the connecting rod (4). At least part of the handle (20) is fitted onto the sleeve (19) and is fixedly connected to the sleeve (19).

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