A built-in hydraulic drive pneumatic diaphragm actuator
By incorporating a hydraulic drive mechanism into the pneumatic diaphragm actuator, and utilizing the hydraulic drive mechanism and piston ring structure, the problem of increased actuator size and weight under high output thrust is solved, achieving efficient automatic valve stem adjustment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Liupanshan Laboratory
- Filing Date
- 2024-07-25
- Publication Date
- 2026-05-19
AI Technical Summary
When existing pneumatic diaphragm actuators require manual operation under high output thrust, an external drive mechanism such as a worm gear is needed, which increases the height and weight of the actuator, and has low transmission efficiency, making operation time-consuming and labor-intensive.
Design a pneumatic diaphragm actuator with built-in hydraulic drive. By integrating the hydraulic drive mechanism into the valve body, the valve stem can move up and down using the cylinder and piston ring structure of the hydraulic drive mechanism. Combined with the conversion mechanism and oil circuit design, the valve stem can be automatically adjusted.
Without increasing the size and weight of the actuator, it provides a large output thrust, is easy to operate, has high transmission efficiency, and reduces the difficulty of operation.
Smart Images
Figure CN119042391B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of automatic regulating valve actuators, and more specifically to a pneumatic diaphragm actuator with built-in hydraulic drive. Background Technology
[0002] Pneumatic diaphragm control valves are a type of control device in pneumatic unit combination instruments, and are an important component of automatic control systems in production processes. They receive output signals from control instruments to close and open valves, achieving automatic regulation of parameters such as pressure, temperature, flow rate, and liquid level. They are widely used in automatic regulation and remote control in chemical, petroleum, metallurgical, power, and textile industries. Currently, commonly used pneumatic diaphragm control valves mainly consist of a valve mechanism and an actuator, connected by a push rod. The pneumatic diaphragm actuator, as a commonly used drive device for control valves, is used to control and regulate valve opening. Pneumatic diaphragm actuators are most widely used in the control valve industry, offering numerous advantages such as high output force, high control accuracy, long service life, stability and reliability, and low cost.
[0003] Pneumatic diaphragm actuators receive output signals from the control room to open and close valves, achieving automatic regulation of parameters such as medium pressure, temperature, flow rate, and liquid level. They are widely used in automatic regulation and remote control in the petroleum, chemical, metallurgical, power, and pharmaceutical industries. As a commonly used drive device for regulating valves, the pneumatic diaphragm actuator controls and regulates valve opening. Its simple structure, reliable operation, convenient maintenance, and low cost have led to its widespread application. Currently, commonly used pneumatic diaphragm regulating valves mainly consist of a valve mechanism and an actuator, connected by a connecting block.
[0004] However, when a pneumatic diaphragm actuator with high output thrust needs to be operated manually, a separate drive mechanism such as a worm gear is often required outside the actuator. This not only increases the height and weight of the actuator, but also results in low transmission efficiency and time-consuming and labor-intensive operation.
[0005] Therefore, how to provide a built-in hydraulically driven pneumatic diaphragm actuator that can have a large output thrust without increasing the size of the actuator structure is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0006] In view of this, the present invention provides a pneumatic diaphragm actuator with built-in hydraulic drive, which aims to solve the above-mentioned technical problems.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] A pneumatic diaphragm actuator with built-in hydraulic drive, comprising:
[0009] support
[0010] A valve body is fixed to the top of the bracket; the inner cavity of the valve body is divided into a spring cavity and an air cavity from top to bottom by a diaphragm.
[0011] An annular hydraulic cylinder is disposed within the air chamber and fixed to the bottom wall of the valve body.
[0012] A valve stem is located within the frame of the bracket and arranged perpendicular to its top surface. Its top end passes through the annular cavity of the annular cylinder and is fixed to the diaphragm.
[0013] The hydraulic drive mechanism has a cylinder body fixed at the top of the bracket and placed in the air chamber. Its output end abuts against the diaphragm to drive the diaphragm to move the valve stem up and down. The hydraulic drive mechanism is connected to the annular cylinder through an oil circuit to relieve pressure and reset.
[0014] A switching mechanism is fixed to the outer wall of the bracket. The switching mechanism is connected to the annular oil cylinder and the hydraulic drive mechanism through oil circuits to switch the oil circuits.
[0015] The beneficial effect of the above technical solution is that the valve body has a built-in hydraulic drive mechanism, which can drive the diaphragm to move up and down, thereby driving the valve stem to move up and down, achieving the purpose of adjusting the regulating valve parameters. Preferably, the valve body includes a diaphragm housing, a first diaphragm cover, a second diaphragm cover, a support plate, and a spring;
[0016] The membrane shell is open at both ends, with the first membrane cover covering the top of the membrane shell and the second membrane cover covering the bottom of the membrane shell; the periphery of the membrane sheet is fixed to the inner wall of the membrane shell; the periphery of the support plate slides against the inner wall of the membrane shell, and its panel abuts against the top surface of the membrane sheet; the spring is disposed in the spring cavity, with one end bolted to the inner wall of the top of the first membrane cover and the other end abutting against the panel of the support plate.
[0017] The beneficial effect of the above technical solution is that when the hydraulic drive mechanism supplies oil, it pushes the diaphragm and the support plate to move upward, at which time the spring is compressed; when the hydraulic drive is depressurized, the spring returns to its initial state, pushing the support plate and the template downward, at which time the second piston ring and the first piston ring are synchronously reset under the action of the spring force.
[0018] Preferably, the hydraulic drive mechanism includes a hydraulic cylinder, a first piston ring, and a second piston ring;
[0019] The top of the bracket is provided with an assembly groove, and the valve body is fastened with a tray corresponding to the bottom wall of the assembly groove. The tray is located in the air cavity and its top surface abuts against the bottom surface of the diaphragm.
[0020] The hydraulic cylinder is annular and sleeved and fixed on the outer wall of the top of the valve stem. Its lower end is fitted into the assembly groove, and its upper end extends into the inner cavity of the tray. A first oil cavity is formed between the inner wall and the outer wall of the hydraulic cylinder.
[0021] The inner cavity of the first piston ring is a second oil cavity that communicates with the first oil cavity, and its outer wall slides against the inner wall of the hydraulic cylinder corresponding to the first oil cavity; the outer wall of the second piston ring slides against the inner wall of the first piston ring, and its top end abuts against the top wall of the tray.
[0022] The annular cylinder is sleeved around the periphery of the tray, and the first oil chamber is connected to the oil chamber of the annular cylinder through a first oil pipe. A shut-off valve is fixed on the first oil pipe.
[0023] The beneficial effects of the above technical solution are that the hydraulic oil in the first oil chamber can enter the second oil chamber to drive the first piston ring to rise, and the hydraulic oil in the second oil chamber can drive the second piston ring to rise. The first piston ring abuts against the tray, which can push the tray to drive the diaphragm to synchronously drive the valve stem to slide upward and compress the spring. When the shut-off valve is opened, the hydraulic oil in the first oil chamber flows into the annular oil cylinder. When the hydraulic oil in the second oil chamber flows back to the first oil chamber, the spring returns to its original position. Under the action of the spring force, the first piston ring and the second piston ring slide downward into the hydraulic cylinder, thereby causing the valve stem to move downward. The valve stem can reciprocate up and down by switching the hydraulic oil in the first oil chamber, the second oil chamber and the annular oil cylinder oil chamber.
[0024] Preferably, guide sleeves and sealing rings are fitted between the outer periphery of the bottom end of the first piston ring and the inner wall of the hydraulic cylinder, and between the outer periphery of the bottom end of the second piston ring and the inner wall of the first piston ring. The guide sleeves guide the up-and-down movement of the first and second piston rings, and the sealing rings ensure a sealing effect between the first piston ring and the hydraulic cylinder, and between the second piston ring and the first piston ring, preventing gas leakage.
[0025] Preferably, the hydraulic cylinder has multiple protrusions fixed to the inner wall of the first oil chamber and the inner wall of the first piston ring to limit the movement of the first piston ring and the second piston ring, respectively. The protrusions limit the stroke of the first and second piston rings, preventing cylinder disengagement.
[0026] Preferably, the conversion mechanism includes a cylinder base, a cam, a piston, a push rod, and a handwheel;
[0027] One end face of the cylinder seat is fixed to the outer wall of the bracket, and the cam is rotatably connected to the other end of the cylinder seat. The end face of the cam facing the inner cavity of the cylinder seat is curved.
[0028] The piston is slidably connected to the cavity between the cylinder seat and the cam, and a hydraulic cavity is formed between the end face of the piston away from the cam and the inner wall of the cylinder seat; the two ends of the push rod are respectively fixed to the end face of the piston near the cam and the curved surface; the handwheel is fixed to the end of the cam away from the cylinder seat via a connecting rod;
[0029] The cylinder seat is connected to the oil chamber of the annular cylinder and the first oil chamber via oil pipes relative to the outer wall of the hydraulic chamber.
[0030] Preferably, a first connector is fixed to the outer wall of the cylinder seat away from the piston, and the first connector is connected to the first oil chamber through a second oil pipe; a second connector is fixed to the outer wall of the cylinder seat near the piston, and the second connector is connected to the oil chamber of the annular cylinder through a third oil pipe.
[0031] Both the second oil pipe and the third oil pipe are equipped with one-way valves.
[0032] The beneficial effect of the above technical solution is that the check valve on the second oil pipe can only allow the hydraulic oil in the hydraulic chamber to enter the first oil chamber, and the check valve on the third oil pipe can only allow the hydraulic oil in the annular cylinder to enter the hydraulic chamber.
[0033] The handwheel drives the cam to rotate. The rotation of the cam surface can drive the piston to reciprocate through the push rod, thereby changing the volume of the hydraulic chamber. When the piston moves and the volume of the hydraulic chamber decreases, the hydraulic oil in the hydraulic chamber is pushed into the first oil chamber. At this time, due to the restriction of the one-way valve of the third oil pipe, the hydraulic oil in the annular cylinder will not enter the hydraulic chamber. The hydraulic oil in the first oil chamber pushes the first piston ring to slide upward. After the hydraulic oil in the first oil chamber enters the second oil chamber, it can push the second piston ring to slide upward, thereby realizing the upward movement of the valve stem.
[0034] When the hydraulic drive mechanism needs to be reset, the shut-off valve is opened, and the hydraulic oil in the first oil chamber enters the annular oil cylinder through the first oil pipe. When the piston moves and the volume of the hydraulic chamber increases, the hydraulic oil in the annular oil cylinder enters the hydraulic chamber. At this time, the hydraulic oil in the first oil chamber will not flow back into the hydraulic chamber due to the restriction of the one-way valve on the second oil pipe. The first piston ring and the second piston ring complete the pressure relief and reset under the action of the spring force.
[0035] Preferably, a raised edge is fixed to the periphery of the outer wall of the hydraulic cylinder, and the raised edge is engaged between the top surface of the bracket and the bottom surface of the valve body. The hydraulic drive mechanism can be fixed between the tray cavity and the bracket via the assembly slot. The raised edge engages the upper part of the hydraulic drive mechanism within the tray cavity, thus embedding the hydraulic drive mechanism within the valve body. This ingenious structure reduces the size and weight of the pneumatic diaphragm actuator while enabling it to provide greater output power.
[0036] Preferably, a guide bushing is fitted between the outer wall of the valve stem and the inner wall of the hydraulic cylinder. The bushing provides guidance for the movement of the valve stem.
[0037] Preferably, the bottom end of the bracket can be bolted to the mounting seat of the regulating valve, and the bottom end of the valve stem can be screwed onto the regulating rod of the regulating valve via a fastening seat. The pneumatic diaphragm actuator with a built-in hydraulic drive mechanism can provide sufficient output force without increasing the weight and size of the actuator, thus achieving automatic control of the regulating valve parameters.
[0038] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a pneumatic diaphragm actuator with built-in hydraulic drive. The hydraulic drive mechanism built into the valve body does not increase the height and weight of the actuator. The conversion mechanism sends hydraulic oil into the hydraulic drive mechanism to drive the valve stem. Compared with the existing drive device, it is small in size, light in weight, easy to operate, and saves time and effort. Attached Figure Description
[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0040] Figure 1 A cross-sectional view of the actuator provided by the present invention;
[0041] Figure 2 A cross-sectional view of the hydraulic drive mechanism provided by the present invention;
[0042] Figure 3 A cross-sectional view of the conversion mechanism provided by the present invention;
[0043] Figure 4 A schematic diagram of the cam structure of the conversion mechanism provided by the present invention;
[0044] Figure 5 A schematic diagram of the piston structure of the conversion mechanism provided by the present invention.
[0045] in,
[0046] 1-Bracket; 2-Valve body; 21-First diaphragm cover; 22-Diaphragm housing; 23-Second diaphragm cover; 24-Diaphragm; 25-Spring; 26-Pattern; 27-Pattern plate; 3-Hydraulic drive mechanism; 31-Hydraulic cylinder; 32-Guide sleeve; 33-First piston ring; 34-Second piston ring; 35-Raised edge; 36-Protrusion; 37-Bushing; 4-Conversion mechanism; 41-Cylinder seat; 42-Piston; 43-Cam; 44-Push rod; 45-Curved surface; 46-First connector; 47-Second structure; 48-Handwheel; 5-Valve stem; 6-Check valve; 7-Stop valve; 8-Annular cylinder. Detailed Implementation
[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0048] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, 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 this invention.
[0049] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded 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 according to the specific circumstances.
[0051] 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.
[0052] This invention discloses a pneumatic diaphragm actuator with built-in hydraulic drive, comprising:
[0053] Bracket 1,
[0054] Valve body 2 is fixed to the top of bracket 1; the inner cavity of valve body 2 is divided into spring cavity and air cavity from top to bottom by diaphragm 24.
[0055] An annular oil cylinder 8 is installed inside the air chamber and fixed to the bottom wall of the valve body 2.
[0056] Valve stem 5 is located in the frame of bracket 1 and arranged perpendicular to its top surface. Its top end passes through the annular cavity of annular cylinder 8 and is fixed to diaphragm 24.
[0057] The hydraulic drive mechanism 3 has its cylinder body fixed at the top of the bracket 1 and placed in the air chamber. Its output end abuts against the diaphragm 24 to drive the diaphragm 24 to move the valve stem 5 up and down. The hydraulic drive mechanism 3 is connected to the annular oil cylinder 8 through the oil circuit to relieve pressure and reset.
[0058] The conversion mechanism 4 is fixed to the outer wall of the bracket 1. The conversion mechanism 4 is connected to the annular oil cylinder 8 and the hydraulic drive mechanism 3 through oil circuits to switch the oil circuits.
[0059] See appendix Figure 1 The valve stem is driven up and down by a hydraulic drive mechanism. The hydraulic drive mechanism is integrated into the valve body, which can ensure that the actuator has a large output power without adding extra weight and volume, so as to meet the diverse needs of automated control of regulating valve parameters.
[0060] To further optimize the above technical solution, the valve body 2 includes a diaphragm housing 22, a first diaphragm cover 21, a second diaphragm cover 23, a support plate 27, and a spring 25;
[0061] The membrane shell 22 is open at both ends. The first membrane cover 21 covers the top of the membrane shell 22, and the second membrane cover 23 covers the bottom of the membrane shell 22. The periphery of the diaphragm 24 is fixed to the inner wall of the membrane shell 22. The periphery of the support plate 27 slides against the inner wall of the membrane shell 22, and its panel abuts against the top surface of the diaphragm 24. The spring 25 is located in the spring cavity, with one end bolted to the inner wall of the top of the first membrane cover 21 and the other end abutting against the panel of the support plate 27.
[0062] The diaphragm housing is connected to the first diaphragm cover and the second diaphragm cover by bolts. The detachable design facilitates the installation, disassembly, maintenance and repair of the actuator. The diaphragm is always in contact with the panel of the support plate and drives the support plate to slide up and down along the inner wall of the diaphragm housing in the spring cavity to compress the spring.
[0063] In this embodiment, the hydraulic drive mechanism 3 includes a hydraulic cylinder 31, a first piston ring 33, and a second piston ring 34;
[0064] The top of the bracket 1 is provided with an assembly groove, and the valve body 2 is fastened with a tray 26 corresponding to the bottom wall of the assembly groove. The tray 26 is located in the air cavity and its top surface abuts against the bottom surface of the diaphragm 24.
[0065] The hydraulic cylinder 31 is annular and is sleeved and fixed on the outer wall of the top end of the valve stem 5. Its lower end is fitted into the assembly groove and its upper end extends into the inner cavity of the tray 26. A first oil cavity is formed between the inner wall and the outer wall of the hydraulic cylinder 31.
[0066] The inner cavity of the first piston ring 33 is a second oil cavity that communicates with the first oil cavity, and its outer wall slides against the inner wall of the hydraulic cylinder 31 corresponding to the first oil cavity; the outer wall of the second piston ring 34 slides against the inner wall of the first piston ring 33, and its top end abuts against the top wall of the tray 26.
[0067] Among them, the annular oil cylinder 8 is sleeved on the periphery of the tray 26, the first oil chamber is connected to the oil chamber of the annular oil cylinder 8 through the first oil pipe, and the shut-off valve 7 is fixed on the first oil pipe.
[0068] like Figure 1 and 2 The hydraulic drive mechanism is a multi-stage nested piston ring drive mechanism. The hydraulic cylinder can be extended in stages by controlling the hydraulic oil. The second piston ring pushes the pallet to move, and the pallet can push the diaphragm to move, thereby realizing the movement of the valve stem.
[0069] To further optimize the above technical solution, constrain the degree of freedom of movement of the first piston ring and the second piston ring, and ensure no air leakage, a guide sleeve 32 and a sealing ring are fitted between the outer periphery of the bottom end of the first piston ring 33 and the inner wall of the hydraulic cylinder 31, and between the outer periphery of the bottom end of the second piston ring 34 and the inner wall of the first piston ring 33.
[0070] To further optimize the above technical solution and prevent the first piston ring from dislodging from the first oil chamber and the second oil chamber, the hydraulic cylinder 31 has multiple protrusions 36 fixed relative to the inner wall of the first oil chamber and the inner wall of the first piston ring 33 to limit the stroke of the first piston ring 33 and the second piston ring 34 respectively.
[0071] In this embodiment, the conversion mechanism 4 includes a cylinder seat 41, a cam 43, a piston 42, a push rod 44, and a handwheel 48;
[0072] One end face of the cylinder seat 41 is fixed to the outer wall of the bracket 1, and the cam 43 is rotatably connected to the other end of the cylinder seat 41. The end face of the cam 43 facing the inner cavity of the cylinder seat 41 is a curved surface 45.
[0073] The piston 42 is slidably connected in the cavity between the cylinder seat 41 and the cam 43. A hydraulic cavity is formed between the end face of the piston 42 away from the cam 43 and the inner wall of the cylinder seat 41. The two ends of the push rod 44 are respectively fixed on the end face of the piston 42 near the cam 43 and the curved surface 45. The handwheel 48 is fixed to the end of the cam 43 away from the cylinder seat 41 through the connecting rod.
[0074] Among them, the cylinder seat 41 is connected to the oil chamber of the annular cylinder 8 and the first oil chamber through oil pipes relative to the outer wall of the hydraulic chamber.
[0075] like Figures 3-5 As shown, the handwheel can drive the cam to rotate, and the rotation of the cam can be converted into the linear motion of the piston. The piston can change the volume of the hydraulic chamber in the reciprocating motion, and the flow direction of the hydraulic oil can be controlled by the change of volume, so as to extend or reset the piston ring of the hydraulic drive mechanism.
[0076] In some other specific embodiments, the cam surface is formed by four convex peaks and four concave valleys smoothly connected. During the rotation of the cam, the push rod moves with the undulation of the surface to drive the piston to reciprocate.
[0077] To further optimize the above technical solution, a first connector 46 is fixed on the outer wall of the cylinder seat 41 away from the piston 42, and the first connector 46 is connected to the first oil chamber through a second oil pipe; a second connector 47 is fixed on the outer wall of the cylinder seat 41 close to the piston 42, and the second connector 47 is connected to the oil chamber of the annular cylinder 8 through a third oil pipe.
[0078] One-way valves 6 are fixed on both the second and third oil pipes.
[0079] The check valve on the second oil pipe can only allow the hydraulic oil in the hydraulic chamber to enter the first oil chamber, and the check valve on the third oil pipe can only allow the hydraulic oil in the annular cylinder to enter the hydraulic chamber.
[0080] When the volume of the hydraulic chamber increases, it is equivalent to the hydraulic chamber having suction, which can draw the hydraulic oil in the annular cylinder into the hydraulic chamber, while the hydraulic oil in the first oil chamber will not flow into the hydraulic chamber under the restriction of the check valve.
[0081] When the volume of the hydraulic chamber decreases, it is equivalent to the hydraulic chamber having a thrust, pushing the hydraulic oil in the hydraulic chamber into the first oil chamber and pushing the first piston ring and the second piston ring out. At this time, the hydraulic oil in the hydraulic chamber will not be pushed into the annular cylinder under the action of the one-way valve of the third oil pipe, ensuring that the hydraulic oil has only one circuit each time the hydraulic chamber changes (that is, when the volume of the hydraulic chamber increases, the hydraulic oil flow direction is annular cylinder oil chamber → hydraulic chamber; when the volume of the hydraulic chamber decreases, the hydraulic oil flow direction is hydraulic chamber → first oil chamber).
[0082] When the hydraulic system determines that a reset is needed, the shut-off valve is opened, and the hydraulic oil in the first oil chamber flows into the annular oil cylinder.
[0083] The specific working principle of the hydraulic drive mechanism is as follows:
[0084] As the piston rings extend, hydraulic oil in the hydraulic chamber flows into the first oil chamber.
[0085] Piston ring reset; hydraulic oil in the first oil chamber → oil chamber in the annular cylinder → hydraulic chamber.
[0086] In some other specific embodiments, a first connecting hole is provided on the top of the bracket, a second connecting hole is provided on the bottom surface of the second diaphragm housing corresponding to and communicating with the first connecting hole, and a third connecting hole is provided on the top surface of the tray corresponding to and communicating with the second connecting hole. The top of the valve stem passes through the first connecting hole, the second connecting hole and the third connecting hole in sequence to enter the air chamber and passes through the diaphragm to be fixed to the support plate. The sliding of the support plate along the inner wall of the diaphragm housing will synchronously drive the valve stem to move up and down.
[0087] To further optimize the above technical solution and ensure the hydraulic drive mechanism is securely fixed, a flange 35 is fixed to the outer periphery of the cylinder body of the hydraulic drive mechanism 3. The flange 35 is engaged between the top surface of the bracket 1 and the bottom surface of the valve body 2. The lower part of the hydraulic cylinder is embedded in the assembly groove at the top of the bracket, and the upper part is fastened by a tray. The hydraulic cylinder is engaged between the bracket and the second diaphragm cover by the flange.
[0088] To further optimize the above technical solution, a guide bushing 37 is fitted between the outer wall of the valve stem 5 and the inner wall of the hydraulic drive mechanism 3 cylinder. The bushing guides the movement of the valve stem and prevents it from deviating from its direction of movement.
[0089] To further optimize the above technical solution, the bottom end of the bracket 1 can be bolted to the mounting seat of the regulating valve, and the bottom end of the valve stem 5 can be screwed onto the regulating rod of the regulating valve through a fastening seat.
[0090] To further optimize the above technical solution, seals are fixed between the outer wall of the valve stem and the top and bottom of the inner wall of the hydraulic cylinder to prevent air leakage from affecting the movement of the valve stem.
[0091] The principle of the actuator provided by this invention is as follows:
[0092] When the shut-off valve is closed, the hydraulic oil in the first oil chamber will not flow into the oil chamber of the annular cylinder;
[0093] Turning the handwheel causes the cam to rotate as well. When the volume in the hydraulic chamber is compressed, the hydraulic oil in the hydraulic chamber is pushed into the first oil chamber. Due to the action of the one-way valve on the third oil pipe, the hydraulic oil in the annular cylinder will not enter the hydraulic chamber. When the volume in the hydraulic chamber increases, the hydraulic oil in the annular cylinder is drawn into the hydraulic chamber. Due to the restriction of the one-way valve on the second oil pipe, the hydraulic oil in the first oil chamber will not flow back into the hydraulic chamber.
[0094] The rotation of the cam drives the piston to perform linear reciprocating motion. During the reciprocating motion, the hydraulic oil in the hydraulic chamber is continuously pushed into the first oil chamber, and the hydraulic oil in the first oil chamber is pushed into the second oil chamber. The first piston ring and the second piston ring extend, causing the tray to push the diaphragm and the support plate together to drive the valve stem to move upward. In this state, the spring is compressed.
[0095] When the hydraulic drive mechanism needs to be reset, the shut-off valve is opened, and the hydraulic oil in the first oil chamber flows into the oil chamber in the annular oil cylinder. At this time, the hydraulic drive mechanism is depressurized, the spring is reset, and the elastic force generated during the spring reset process will push the tray and diaphragm as a whole to move the tray downward, compressing the second piston ring to slide into the second piston ring, and the first piston ring to slide into the first oil chamber.
[0096] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0097] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A pneumatic diaphragm actuator with built-in hydraulic drive, characterized in that, include: Support (1) Valve body (2), the valve body (2) is fixed at the top of the bracket (1); the inner cavity of the valve body (2) is divided into a spring cavity and an air cavity from top to bottom by a diaphragm (24); An annular oil cylinder (8) is disposed in the air chamber and fixed to the bottom wall of the valve body (2); Valve stem (5), the valve stem (5) is located in the frame of the bracket (1) and arranged perpendicular to its top surface, and its top end passes through the annular cavity of the annular cylinder (8) and is fixed to the diaphragm (24); The hydraulic drive mechanism (3) has its cylinder body fixed to the top of the bracket (1) and placed in the air chamber. Its output end abuts against the diaphragm (24) to drive the diaphragm (24) to drive the valve stem (5) to move up and down. The hydraulic drive mechanism (3) is connected to the annular oil cylinder (8) through the oil circuit to relieve pressure and reset. The hydraulic drive mechanism (3) includes a hydraulic cylinder (31), a first piston ring (33), and a second piston ring (34). The top of the bracket (1) is provided with an assembly groove, and the valve body (2) is fitted with a tray (26) corresponding to the bottom wall of the assembly groove. The tray (26) is located in the air cavity and its top surface abuts against the bottom surface of the diaphragm (24). The hydraulic cylinder (31) is annular and is sleeved and fixed on the outer wall of the top end of the valve stem (5). Its lower end is fitted into the assembly groove and its upper end extends into the inner cavity of the tray (26). A first oil cavity is formed between the inner wall and the outer wall of the hydraulic cylinder (31). A guide bushing (37) is sleeved between the outer wall of the valve stem (5) and the inner wall of the cylinder of the hydraulic drive mechanism (3). The inner cavity of the first piston ring (33) is a second oil cavity that communicates with the first oil cavity, and its outer wall slides against the inner wall of the hydraulic cylinder (31) corresponding to the first oil cavity; the outer wall of the second piston ring (34) slides against the inner wall of the first piston ring (33), and its top end abuts against the top wall of the tray (26); The annular cylinder (8) is sleeved on the periphery of the tray (26), and the first oil chamber is connected to the oil chamber of the annular cylinder (8) through the first oil pipe. A shut-off valve (7) is fixed on the first oil pipe. The conversion mechanism (4) is fixed to the outer wall of the bracket (1). The conversion mechanism (4) is connected to the annular oil cylinder (8) and the hydraulic drive mechanism (3) through oil circuits to switch the oil circuits. The conversion mechanism (4) includes an oil cylinder seat (41), a cam (43), a piston (42), a push rod (44), and a handwheel (48). One end face of the cylinder seat (41) is fixed to the outer wall of the bracket (1), and the cam (43) is rotatably connected to the other end of the cylinder seat (41). The end face of the cam (43) facing the inner cavity of the cylinder seat (41) is a curved surface (45). The piston (42) is slidably connected to the cavity between the cylinder seat (41) and the cam (43). A hydraulic cavity is formed between the end face of the piston (42) away from the cam (43) and the inner wall of the cylinder seat (41). The two ends of the push rod (44) are respectively fixed on the end face of the piston (42) near the cam (43) and the curved surface (45). The handwheel (48) is fixed to the end of the cam (43) away from the cylinder seat (41) through a connecting rod. The cylinder seat (41) is connected to the oil chamber of the annular cylinder (8) and the first oil chamber respectively via oil pipes relative to the outer wall of the hydraulic chamber; The valve body (2) includes a diaphragm housing (22), a first diaphragm cover (21), a second diaphragm cover (23), a support plate (27), and a spring (25); the diaphragm housing (22) is open at both ends, the first diaphragm cover (21) covers the top end of the diaphragm housing (22), and the second diaphragm cover (23) covers the bottom end of the diaphragm housing (22); the periphery of the diaphragm (24) is fixed to the inner wall of the diaphragm housing (22); the periphery of the support plate (27) slides against the inner wall of the diaphragm housing (22), and its panel abuts against the top surface of the diaphragm (24); the spring (25) is located in the spring cavity, one end of which is bolted to the inner wall of the top end of the first diaphragm cover (21), and the other end abuts against the panel of the support plate (27); A first connector (46) is fixed to the outer wall of the cylinder seat (41) away from the piston (42), and the first connector (46) is connected to the first oil chamber through a second oil pipe; a second connector (47) is fixed to the outer wall of the cylinder seat (41) near the piston (42), and the second connector (47) is connected to the oil chamber of the annular cylinder (8) through a third oil pipe; a one-way valve (6) is fixed on both the second oil pipe and the third oil pipe. The outer periphery of the cylinder body of the hydraulic drive mechanism (3) is fixed with a protrusion (35), which is engaged between the top surface of the bracket (1) and the bottom surface of the valve body (2); the hydraulic cylinder is engaged between the bracket and the second diaphragm cover through the protrusion.
2. The pneumatic diaphragm actuator with built-in hydraulic drive according to claim 1, characterized in that, A guide sleeve (32) and a sealing ring are fitted between the outer periphery of the bottom end of the first piston ring (33) and the inner wall of the hydraulic cylinder (31), and between the outer periphery of the bottom end of the second piston ring (34) and the inner wall of the first piston ring (33).
3. The pneumatic diaphragm actuator with built-in hydraulic drive according to claim 1, characterized in that, The hydraulic cylinder (31) has multiple protrusions (36) fixed relative to the inner wall of the first oil chamber and the inner wall of the first piston ring (33) to limit the first piston ring (33) and the second piston ring (34) respectively.
4. A pneumatic diaphragm actuator with built-in hydraulic drive according to any one of claims 1 to 3, characterized in that, The bottom end of the bracket (1) can be bolted to the mounting seat of the regulating valve, and the bottom end of the valve stem (5) can be screwed onto the regulating rod of the regulating valve through a fastening seat.