Double-cylinder hydraulic control friction-free two-way sealing butterfly valve

Abstract

The utility model relates to a double-cylinder hydraulic control friction-free two-way sealing butterfly valve, which comprises a butterfly valve and a hydraulic control actuator, the butterfly valve comprises a valve body, a valve seat, a butterfly plate and a valve rod, and the hydraulic control actuator comprises a hydraulic oil cylinder and a gear-rack transmission mechanism; the hydraulic control actuator is characterized in that a left oil cylinder and a right oil cylinder are symmetrically arranged at the two ends of a shell to form a double-oil-cylinder structure, the left oil cylinder and the right oil cylinder control opening and closing of a butterfly valve in a linkage mode, and damage to a piston sealing ring caused by eccentric force generated when a spring pushes a piston to be closed in the prior art is avoided; the butterfly plate is of a double-sealing-face structure, sealing faces on the two sides are matched with double valve seats in a valve body channel to form a double-sealing pair, and high-performance sealing of bidirectional media is achieved. The valve seat is a hydraulic control floating valve seat, in the opening and closing process, a hydraulic mechanism firstly pushes the double valve seats to be separated from the butterfly plate sealing face, friction-free opening and closing are achieved, and the valve has the advantages of being reliable in sealing performance, long in product service life and the like.

Description

Technical Field

[0001] The utility model relates to a bidirectional sealing butterfly valve, in particular to a fast-closing frictionless bidirectional sealing butterfly valve. The utility model is suitable for bidirectional sealing medium working conditions in thermal power, water conservancy, energy, chemical industry and other industries. Background Art

[0002] The actuator of a traditional hydraulically controlled butterfly valve uses a cylinder-opening and spring-closing structure. When the actuator solenoid valve is closed, the spring quickly pushes the cylinder to close the valve. Due to the radial clearance between the spring and the cylinder body, the two cannot always maintain high concentricity. In the process of the spring pushing the piston to close, an eccentric force is generated on the piston, causing irreversible damage to the sealing ring embedded in the outer circumference of the piston and deformation of the spring. Moreover, during rapid emergency shut-off, it is easy to cause wear and scratching of the soft sealing ring of the butterfly valve. Even in the engaged state, the indentation on the sealing surface during rapid opening and closing cannot be restored, causing seal leakage. Especially in conditions where critical projects are frequently shut off, it is easy for rapid closing to fail, resulting in system equipment loss or shutdown. In addition, existing quick-closing butterfly valves only have a one-way sealing function and cannot be used in bidirectional flow medium conditions. Summary of the Invention

[0003] The purpose of the utility model is to address the problems existing in the prior art and provide a double-cylinder hydraulically controlled frictionless bidirectional sealing butterfly valve which adopts double cylinders to push double butterfly plates for synchronous frictionless opening and closing, has reliable sealing performance, long product service life and has a bidirectional sealing function.

[0004] The technical solution for achieving the purpose of this utility model is:

[0005] A double-cylinder hydraulically controlled frictionless bi-directional seal butterfly valve, comprising a butterfly valve and a hydraulically controlled actuator. The butterfly valve includes a valve body, a valve seat, a butterfly plate and a valve stem. The hydraulically controlled actuator part includes a hydraulic cylinder and a gear-rack transmission mechanism. The housing of the hydraulically controlled actuator is mounted on the upper end of the valve body through a bracket. The upper end of the valve stem is fixedly connected to the center of the gear, and the lower end is fixedly connected to the butterfly plate through a pin shaft. The butterfly plate is entirely placed in the valve body passage and cooperates with the valve seat to form a sealing pair. The gear and the rack are meshed and installed in the housing. Its characteristics are: the hydraulically controlled actuator adopts a double-cylinder structure with a left cylinder and a right cylinder symmetrically arranged at both ends of the housing. The piston rods of the left cylinder and the right cylinder are respectively connected to the left and right ends of the rack. The rodless chambers of the left cylinder and the right cylinder are respectively connected to a hydraulic mechanism through a hydraulic control device. Sealing surfaces are respectively arranged on both end faces of the butterfly plate to form a double-sealing surface structure. The valve seat adopts a double-valve seat structure with a left valve seat and a right valve seat arranged in the valve body passage on both sides of the valve stem shaft hole. The left valve seat and the right valve seat form a double-sealing pair structure that cooperates with the sealing surfaces on both sides of the butterfly plate. The left valve seat and the right valve seat adopt hydraulically controlled floating valve seats. The hydraulically controlled floating valve seat is composed of a piston-type sealing ring axially movably installed in the valve body passage through a gland. A first hydraulic chamber is provided between the piston-type sealing ring and the valve body, and a second hydraulic chamber is provided between the piston-type sealing ring and the gland. The first hydraulic chamber and the second hydraulic chamber are respectively connected to the hydraulic mechanism through a hydraulic control device.

[0006] In the above technical solution, the hydraulic control device includes an electromagnetic directional valve and a pressure-locking solenoid valve. The two outlets of the electromagnetic directional valve are respectively connected to the oil inlet holes of the left cylinder and the right cylinder. The inlet of the electromagnetic directional valve is connected to the hydraulic mechanism. Pressure-locking solenoid valves are respectively arranged between the oil inlet holes of the left cylinder and the right cylinder and the electromagnetic directional valve. The hydraulic control device includes a pressure-holding solenoid valve and a two-position three-way solenoid valve. The first hydraulic chamber and the second hydraulic chamber are respectively connected to the two outlet ends of the two-position three-way solenoid valve through the pressure-holding solenoid valve. The inlet of the two-position three-way solenoid valve is connected to the hydraulic mechanism. The electromagnetic directional valve, the pressure-locking solenoid valve, the pressure-holding solenoid valve and the two-position three-way solenoid valve are controlled by the instructions of a PLC control system.

[0007] In the above technical solution, an adjustable pressing device is arranged between the back of the rack and the housing. The adjustable pressing device is composed of a friction block and an adjusting rod. The adjusting rod is installed in the threaded hole of the positioning cover by a nut. The positioning cover is fixedly installed on the housing. The friction block is installed between the back of the rack and the lower end face of the adjusting rod.

[0008] In the above technical solution, a buffer adjusting device is arranged in the cylinder heads of the left cylinder and the right cylinder. The buffer adjusting device is composed of a buffer rod, a buffer spring and a buffer adjusting rod. The buffer adjusting rod is installed in the axial threaded hole of the cylinder head by a locking nut. The buffer spring is installed between the buffer adjusting rod and the buffer rod. The buffer rod has a central hole communicating with the oil inlet hole on the cylinder head.

[0009] In the above technical solution, a mechanical locking device is provided between the piston-type sealing ring and the gland, and the mechanical locking device is composed of a locking rod installed in a screw hole of the gland.

[0010] In the above technical solution, a support ring is provided between the piston-type sealing ring and the gland, and the support ring is fixedly installed between the gland and the end face of the valve body channel by bolts.

[0011] The beneficial effects of the present invention compared with the prior art are:

[0012] 1. The hydraulic actuator adopts a double-cylinder structure. The left and right cylinders work together to control the opening and closing of the butterfly valve, avoiding the damage to the piston seal caused by the eccentric force generated by the spring pushing the piston to close in the existing technology. Its sealing performance is reliable and the product service life is long.

[0013] 2. The butterfly plate adopts a double sealing surface structure. The sealing surfaces on both sides cooperate with the double valve seats in the valve body channel to form a double sealing pair, achieving high-performance sealing for bidirectional media;

[0014] 3. The valve seat adopts a hydraulically controlled floating valve seat, and the double valve seats are controlled by the hydraulic mechanism through the PLC control system command; before opening the valve, the hydraulic mechanism first pushes the double valve seats away from the butterfly plate sealing surface, and then the hydraulic actuator drives the butterfly plate to rotate and open; after the butterfly plate is closed, the hydraulic mechanism pushes the double valve seats and the butterfly plate to press together to form a double sealing pair sealing structure; realizing frictionless opening and closing between the butterfly plate sealing surface and the valve seat sealing surface, reducing the wear of the sealing surface, and improving the sealing performance and service life of the sealing pair. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the present utility model.

[0016] Figure 2 This utility model Figure 1 Structural cross-section view of the hydraulic control actuator.

[0017] Figure 3 This utility model Figure 1 A magnified view of the local structure at point A.

[0018] Figure 4 This utility model Figure 1 Enlarged view of the local structure at point B in the middle.

[0019] Figure 5 This utility model Figure 2 Schematic diagram of the structure in the CC direction.

[0020] In the figure: 1 valve body, 2 butterfly plate, 3 valve stem, 4 pin shaft, 5 pressure ring, 6 sealing ring, 7 piston-type sealing ring, 8 gland, 9 packing device, 10 bracket, 11 support ring, 12 second hydraulic chamber, 13 first hydraulic chamber, 14 housing, 15 gear, 16 rack, 17 piston rod, 18 piston, 19 front end cover, 20 cylinder block, 21 buffer rod, 22 cylinder head, 23 adjusting rod, 24 friction block, 25 oil delivery hole, 26 locking rod, 27 nut, 28 positioning cover, 29 buffer adjusting rod, lock nut 30. Specific implementation mode

[0021] As Figure 1 shown in the double-cylinder hydraulically controlled frictionless bi-directional sealing butterfly valve, which comprises a butterfly valve and a hydraulically controlled actuator. The butterfly valve includes a valve body 1, a valve seat, a butterfly plate 2 and a valve stem 3. The hydraulically controlled actuator part includes a hydraulic cylinder and a gear-rack transmission mechanism. The hydraulic cylinder is composed of a cylinder block 20, a piston 18, a piston rod 17, a cylinder head 22 and a front end cover 19. The housing 14 of the hydraulically controlled actuator is installed on the upper end of the valve body 1 through a bracket 10. The upper end of the valve stem 3 is fixedly connected to the center of the gear 15, and the lower end is fixedly connected to the butterfly plate 2 through a pin shaft 4. The butterfly plate 2 is entirely placed in the passage of the valve body 1 and cooperates with the valve seat to form a sealing pair. A packing device 9 is arranged between the outer cylindrical surface of the valve stem 3 and the stuffing box at the upper end of the valve body 1. The gear 15 and the rack 16 are meshed with each other and installed in the housing 14. It is characterized in that: the hydraulic cylinder adopts a double-cylinder structure composed of two left cylinders and right cylinders with the same structure. The left cylinder and the right cylinder are symmetrically installed at both ends of the housing 14 through the front end cover 19. The piston rods 17 of both are respectively connected to the left and right ends of the rack 16. As Figure 2As shown, the rodless chambers of the left oil cylinder and the right oil cylinder are connected to the hydraulic mechanism through the hydraulic control device at the outlet of the oil delivery hole 25 respectively. The rodless chambers of the left oil cylinder and the right oil cylinder form a closed oil circuit with the hydraulic mechanism through the hydraulic control device, that is, when the hydraulic oil of the hydraulic mechanism is injected into the rodless chamber of the left oil cylinder, the hydraulic oil in the rodless chamber of the right oil cylinder flows back to the hydraulic mechanism. Conversely, when the hydraulic oil of the hydraulic mechanism is injected into the rodless chamber of the right oil cylinder, the hydraulic oil in the rodless chamber of the left oil cylinder flows back to the hydraulic mechanism. The piston rods 17 of the left oil cylinder and the right oil cylinder respectively push the rack 16 transmission gear 15 to drive the valve stem 3 and the butterfly plate 2 to rotate, thereby realizing the opening and closing of the butterfly valve. During the opening and closing process, the piston 18 is always pushed by the hydraulic pressure in the rodless chamber, so that the sealing chamber on the periphery of the piston 18 is uniformly stressed in the circumferential direction, thereby improving the sealing reliability and service life of the hydraulic cylinder; the end faces of the butterfly plate 2 are respectively provided with The sealing surface constitutes a double sealing surface structure, which is composed of a sealing ring 6 fixedly pressed on the end faces of both sides of the butterfly plate 2 through a pressure ring 5. The sealing chamber 6 is symmetrically arranged on both sides of the valve stem 3. The valve seat adopts a double valve seat structure by arranging a left valve seat and a right valve seat in the valve body 1 channel on both sides of the valve stem 3 axial hole. The left valve seat and the right valve seat cooperate with the sealing surfaces on both sides of the butterfly plate 2 in a double sealing pair structure. The sealing pairs on both sides bear the medium pressure in the positive and negative directions respectively, realizing the sealing function of both parties, which is suitable for bidirectional flow medium working conditions; the left valve seat and the right valve seat adopt a hydraulically controlled floating valve seat, and the hydraulically controlled floating valve seat is composed of a piston-type sealing ring 7 axially movably installed in the valve body 1 channel through a pressure cover 8. There is a first hydraulic chamber 13 between the piston-type sealing ring 7 and the valve body 1, and a second hydraulic chamber 12 between the piston-type sealing ring 7 and the pressure cover 8. Figure 3 、 Figure 4 As shown, the first hydraulic chamber 13 and the second hydraulic chamber 12 are respectively connected to the hydraulic mechanism via a hydraulic control device. When the butterfly valve is opened, the hydraulic mechanism first injects hydraulic pressure into the first hydraulic chamber 13 through the hydraulic control device, pushing the piston-type sealing ring 7 axially away from the sealing surface of the butterfly plate 2, and then the hydraulic actuator controls the butterfly valve to open. When the butterfly valve is closed, the hydraulic actuator controls the butterfly valve to close, and then injects hydraulic pressure into the second hydraulic chamber 12 through the hydraulic control device. Simultaneously, the hydraulic pressure in the first hydraulic chamber 13 flows back to the hydraulic mechanism, pushing the piston-type sealing ring 7 axially to pressurize and seal the sealing surface of the butterfly plate 2, and locking the hydraulic pressure in the second hydraulic chamber 12, achieving frictionless opening and closing of the butterfly valve sealing pair.

[0022] The hydraulic control device includes an electromagnetic reversing valve and a pressure locking solenoid valve. The two outlets of the electromagnetic reversing valve are respectively connected to the oil inlet holes 25 of the left oil cylinder and the right oil cylinder. The inlet of the electromagnetic reversing valve is connected to the hydraulic mechanism. When the inlet of the electromagnetic reversing valve is connected to the rodless cavity of the left oil cylinder, the rodless cavity of the right oil cylinder is connected to the oil return port of the electromagnetic reversing valve. Conversely, when the inlet of the electromagnetic reversing valve is connected to the rodless cavity of the right oil cylinder, the rodless cavity of the left oil cylinder is connected to the oil return port of the electromagnetic reversing valve. A pressure locking solenoid valve is respectively installed between the oil inlet holes 25 of the left oil cylinder and the right oil cylinder and the electromagnetic reversing valve. After the piston 18 of the right oil cylinder or the left oil cylinder moves in place, that is, when the butterfly valve is in the fully open or fully closed state, the pressure locking solenoid valve of the oil inlet hole 25 of the right oil cylinder or the left oil cylinder is closed, locking the pressure in the rodless cavity of the right oil cylinder or the left oil cylinder, and keeping the butterfly valve reliably in the closed or open state; The hydraulic control device includes a pressure maintaining solenoid valve and a two-position three-way solenoid valve. The first hydraulic chamber 13 and the second hydraulic chamber 12 are respectively connected to the two outlet ends of the two-position three-way solenoid valve through the pressure maintaining solenoid valve. The inlet of the two-position three-way solenoid valve is connected to the hydraulic mechanism. When the first hydraulic chamber 13 is connected to the inlet of the two-position three-way solenoid valve, the second hydraulic chamber 12 is connected to the oil return port of the two-position three-way solenoid valve, axially pushing the plug-type sealing ring 7 away from the sealing surface of the butterfly plate 2; conversely, when the second hydraulic chamber 12 is connected to the inlet of the two-position three-way solenoid valve, the first hydraulic chamber 13 is connected to the oil return port of the two-position three-way solenoid valve, axially pushing the piston-type sealing ring 7 to press and seal with the sealing surface of the butterfly plate 2, and starting the pressure maintaining solenoid valve after the piston-type sealing ring 7 is pressed and sealed with the sealing surface of the butterfly plate 2, maintaining the sealing state between the piston-type sealing ring 7 and the sealing surface of the butterfly plate 2; The electromagnetic reversing valve, the pressure locking solenoid valve, the pressure maintaining solenoid valve, and the two-position three-way solenoid valve are controlled by the instructions of the PLC control system, and the action sequence of the electromagnetic reversing valve, the pressure locking solenoid valve, the pressure maintaining solenoid valve, and the two-position three-way solenoid valve is controlled according to the set programming program instructions.

[0023] An adjustable pressing device is arranged between the back surface of the rack 16 and the housing 14. The adjustable pressing device consists of a friction block 24 and an adjusting rod 23. The adjusting rod 23 is installed in the threaded hole of the positioning cover 28 by a nut 27. The positioning cover 28 is fixedly installed on the housing 14. The friction block 24 is installed between the back surface of the rack 16 and the lower end surface of the adjusting rod 23. The pressing force between the friction block 24 and the rack 16 is adjusted by the adjusting rod 23 to maintain the reliable meshing between the rack 16 and the gear 15, as Figure 2 、 Figure 5 shown.

[0024] A buffer adjustment device is provided inside the cylinder heads 22 of the left oil cylinder and the right oil cylinder. The buffer adjustment device consists of a buffer rod 21 and a buffer adjustment rod 29. The buffer adjustment rod 29 is installed in the axial screw hole of the cylinder head 22 by a locking nut 30. A spring is provided between the buffer adjustment rod 29 and the buffer rod 21. The buffer rod 21 has a central hole communicating with the oil delivery hole 25 on the cylinder head 22. By adjusting the buffer adjustment rod 29, the compression force of the spring between the buffer adjustment rod 29 and the buffer rod 21 is adjusted, and the buffer force when the piston 18 touches the buffer rod 21 is adjusted to prevent the piston 18 from being damaged by collision, as Figure 2 shown.

[0025] A mechanical locking device is provided between the piston-type sealing ring 7 and the gland 8. The mechanical locking device consists of a locking rod 26 installed in the screw hole of the gland 8. The piston-type sealing ring 7 is pressed tightly by the locking rod 26 to be in sealing cooperation with the sealing ring 6, achieving mechanical locking and forming a maintenance sealing pair for online maintenance of the other sealing pair, as Figure 3 , Figure 4 shown.

[0026] A support ring 11 is provided between the piston-type sealing ring 7 and the gland 8. The support ring 11 is fixedly installed between the gland 8 and the channel end face of the valve body 1 by bolts, facilitating the installation and fitting accuracy of the piston-type sealing ring 7, as Figure 3 , Figure 4 shown.

Claims

1. A double-cylinder hydraulically controlled frictionless bi-directional sealing butterfly valve, comprising a butterfly valve and a hydraulically controlled actuator. The butterfly valve includes a valve body (1), a valve seat, a butterfly plate (2) and a valve stem (3). The hydraulically controlled actuator part includes a hydraulic cylinder and a gear-rack transmission mechanism. The housing (14) of the hydraulically controlled actuator is installed at the upper end of the valve body (1) through a bracket (10). The upper end of the valve stem (3) is fixedly connected to the center of the gear (15), and the lower end is fixedly connected to the butterfly plate (2) through a pin shaft (4). The butterfly plate (2) is placed in the passage of the valve body (1) and cooperates with the valve seat to form a sealing pair. The gear (15) and the rack (16) are meshed with each other and installed in the housing (14). It is characterized in that: The hydraulic cylinder is composed of two left cylinders and two right cylinders with the same structure to form a double-cylinder structure. The left cylinder and the right cylinder are symmetrically installed at both ends of the housing (14). The piston rods (17) of both are respectively connected to the left and right ends of the rack (16). The rodless cavities of the left cylinder and the right cylinder are respectively connected to the hydraulic mechanism through the hydraulic control devices at the outlets of the oil delivery holes (25). The rodless cavities of the left cylinder and the right cylinder form a closed-loop oil circuit with the hydraulic mechanism through the hydraulic control devices; both end faces of the butterfly plate (2) are respectively provided with sealing surfaces to form a double-sealing surface structure. The valve seat is provided with a left valve seat and a right valve seat in the channels of the valve body (1) on both sides of the shaft hole of the valve stem (3) to form a double-valve seat structure. The left valve seat and the right valve seat are in a double-sealing pair structure that cooperates with the sealing surfaces on both sides of the butterfly plate (2); the left valve seat and the right valve seat adopt hydraulically controlled floating valve seats. The hydraulically controlled floating valve seat is composed of a piston-type sealing ring (7) axially movably installed in the channel of the valve body (1) through a gland (8). A first hydraulic chamber (13) is provided between the piston-type sealing ring (7) and the valve body (1), and a second hydraulic chamber (12) is provided between the piston-type sealing ring (7) and the gland (8). The first hydraulic chamber (13) and the second hydraulic chamber (12) are respectively connected to the hydraulic mechanism through hydraulic control devices.

2. The double-cylinder hydraulically controlled frictionless bi-directional sealing butterfly valve according to claim 1, wherein: The hydraulic control device includes an electromagnetic reversing valve and a pressure-locking solenoid valve. The two outlets of the electromagnetic reversing valve are respectively connected to the oil delivery holes (25) of the left cylinder and the right cylinder. The inlet of the electromagnetic reversing valve is connected to the hydraulic mechanism. A pressure-locking solenoid valve is respectively installed between the oil delivery holes (25) of the left cylinder and the right cylinder and the electromagnetic reversing valve; the hydraulic control device includes a pressure-holding solenoid valve and a two-position three-way solenoid valve. The first hydraulic chamber (13) and the second hydraulic chamber (12) are respectively connected to the two outlet ends of the two-position three-way solenoid valve through the pressure-holding solenoid valve. The inlet of the two-position three-way solenoid valve is connected to the hydraulic mechanism; the electromagnetic reversing valve, the pressure-locking solenoid valve, the pressure-holding solenoid valve, and the two-position three-way solenoid valve are controlled by the instructions of the PLC control system.

3. The double-cylinder hydraulically-controlled frictionless bi-directional sealing butterfly valve according to claim 1 or 2, characterized in that: An adjustable pressing device is provided between the back surface of the rack (16) and the housing (14). The adjustable pressing device is composed of a friction block (24) and an adjusting rod (23). The adjusting rod (23) is installed in the threaded hole of the positioning cover (28) by a nut (27). The positioning cover (28) is fixedly installed on the housing (14). The friction block (24) is installed between the back surface of the rack (16) and the lower end surface of the adjusting rod (23).

4. The double-cylinder hydraulically controlled frictionless bi-directional sealing butterfly valve according to claim 3, wherein: A buffer adjusting device is provided in the cylinder heads (22) of the left cylinder and the right cylinder. The buffer adjusting device is composed of a buffer rod (21) and a buffer adjusting rod (29). The buffer adjusting rod (29) is installed in the axial threaded hole of the cylinder head (22) by a locking nut (30). A spring is provided between the buffer adjusting rod (29) and the buffer rod (21). The buffer rod (21) has a central hole communicating with the oil delivery hole (25) on the cylinder head (22).

5. The double-cylinder hydraulically-controlled frictionless bi-directional seal butterfly valve according to claim 4, wherein: at A mechanical locking device is provided between the piston-type sealing ring (7) and the gland (8). The mechanical locking device is composed of a locking rod (26) installed in the threaded hole of the gland (8).

6. The double-cylinder hydraulically controlled frictionless bi-directional sealing butterfly valve according to claim 5, characterized in that: at A support ring (11) is arranged between the piston seal ring (7) and the gland (8), and the support ring (11) is fixedly installed between the gland (8) and the end face of the channel of the valve body (1) by bolts.

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