CN219282556U

CN219282556U - Gate valve driven by internal medium

Info

Publication number: CN219282556U
Application number: CN202320330840.9U
Authority: CN
Inventors: 孙宝杰; 冯忠海; 张阳; 刘祥孟; 鄂义佳; 吴铁; 鄂威; 李毅; 谭术洋; 周宁
Original assignee: Anshan Solenoid Valve Co ltd
Current assignee: Anshan Solenoid Valve Co ltd
Priority date: 2023-02-27
Filing date: 2023-02-27
Publication date: 2023-06-30
Anticipated expiration: 2033-02-27

Abstract

The utility model provides a gate valve driven by an internal medium, and relates to the field of gate valves. The gate valve driven by an internal medium includes: a chamber formed inside the main body of the gate valve, and through which a medium flows; the flashboard component is arranged in the cavity and comprises a valve rod and a flashboard; the self-driving assembly is arranged in the cavity and is connected with the valve rod; the control valve group is communicated with the cavity; the control valve group is provided with a first control position and a second control position; and when the control valve block is in a first control position, the media flow is capable of driving the self-driven assembly to move such that the shutter is closed; when the control valve block is in a second control position, the media flow can drive the self-driven assembly to move such that the shutter opens.

Description

Gate valve driven by internal medium

Technical Field

The present application relates to the field of gate valves, and in particular to a gate valve driven by an internal medium.

Background

The gate valve is a valve capable of controlling the starting and closing of a loop system, at present, a main pipeline system in each field adopts an electric gate valve to control the on-off of the pipeline system, and the electric gate valve drives a screw rod to rotate by utilizing an electric device (comprising a motor and a speed reducing mechanism), so that the fixed gate plate is lifted or pushed down by output moment to realize the opening and closing functions of the gate valve. However, because the temperature and pressure of the loop system are higher during normal operation, and the accident state and extreme abnormal working condition of the system are required to be considered, the gate valve needs to meet the opening and closing requirements of large pressure difference, and the medium pressure on the gate plate of the gate valve and the friction force between the gate plate and the valve seat are huge. In order to overcome the external force applied to the flashboard, the electric device of the gate valve is required to output extremely large moment to realize the opening and closing functions of the flashboard. Therefore, the screw rod of the gate valve bears inconceivable rotation torsion and tensile stress, and mechanical performance indexes such as tensile strength, yield strength and the like of most metal materials cannot meet the design requirement of the screw rod of the gate valve. In order to meet the requirements of the materials for the screw rod with ultra-high strength and high hardness, the design needs can be met only by sacrificing the toughness index of the materials, and any part of the screw rod is required to be not subjected to the phenomenon of stress concentration, otherwise, the risk of screw rod fracture occurs in the opening and closing process of the gate valve.

Disclosure of Invention

In view of the above, an object of the present application is to provide a gate valve driven by an internal medium, so as to solve the problem that the existing gate valve driven by an electric device is very easy to cause the breaking of a gate screw.

According to the above object, the present utility model provides a gate valve driven by an internal medium, formed with a body, wherein the body includes:

a chamber formed inside the main body, wherein a medium flows through the chamber;

the flashboard component is arranged in the cavity and comprises a valve rod and a flashboard;

the self-driving assembly is arranged in the cavity and is connected with the valve rod; and

the control valve group is communicated with the cavity; the control valve group is provided with a first control position and a second control position; and when the control valve block is in a first control position, the media flow is capable of driving the self-driven assembly to move such that the shutter is closed; when the control valve block is in a second control position, the media flow can drive the self-driven assembly to move such that the shutter opens.

Preferably, the main body includes a valve body assembly, a cylinder, and a valve cover, which are sequentially connected to form the main body into a cylinder-like shape having an axis; a support table is formed at a middle position in the length direction of the cylinder barrel, and the support table is formed into an annular structure extending toward the axis of the main body.

Preferably, the support table divides the cavity into a first subchamber and a second subchamber along the length direction of the main body, and the first subchamber is positioned at one side close to the valve body assembly; the shutter assembly is located in the first subchamber and the self-driven assembly is located in the second subchamber.

Preferably, the axis of the valve stem coincides with the axis of the body and the valve stem extends into the second subchamber; the through hole of the supporting table is matched with the valve rod.

Preferably, the self-driven assembly comprises a piston member and a pre-tightening member, wherein the piston member and the pre-tightening member are connected with each other and are sleeved at one end of the valve rod, which is close to the valve cover; the end part of the piston part, which is close to the valve cover, is provided with a groove, and the pre-tightening part is arranged in the groove.

Preferably, the self-driven assembly further comprises an upper stroke spool and a lower stroke spool; the upper stroke valve core is connected with the end part of the valve rod, which is close to the valve cover; the downstroke valve core is arranged on the end face of the supporting table, which faces the valve cover, and when the main body is in a closed state, the downstroke valve core is attached to the piston piece.

Preferably, the cylinder is formed with a first connection hole and a second connection hole, which are respectively communicated with the first subchamber and the second subchamber; the first connecting hole and the second connecting hole are connected with the control valve group.

Preferably, the control valve group comprises a pressurizing electromagnetic valve and a pressure relief electromagnetic valve which are sequentially connected, the first connecting hole is communicated with an inlet of the pressurizing electromagnetic valve, and the second connecting hole is communicated with a position where the pressurizing electromagnetic valve and the pressure relief electromagnetic valve are connected; when the control valve group is in a first control position, the pressurizing electromagnetic valve works, and the pressure relief electromagnetic valve does not work; when the control valve group is in the second control position, the pressure relief electromagnetic valve works, and the pressure boosting electromagnetic valve does not work.

Preferably, the gate assembly further comprises a gate sleeve, and the valve rod is connected to the side part of the gate sleeve, which is close to the valve cover; the flashboard is connected to the inside of the flashboard sleeve, and an anti-rotation key is arranged between the flashboard sleeve and the flashboard; the number of the flashboard is two, and the two flashboards are symmetrically arranged about the axis of the main body; the sides of the two shutters facing each other are each formed with a recess in which a spring is provided.

Preferably, the gate valve driven by an internal medium is further provided with a position indicating means and a locking means, the locking means extending into the cavity and being connected to the valve stem, the position indicating means being connected to the locking means.

According to the gate valve driven by the internal medium, the self-driving assembly is connected with the valve rod in the valve cavity, and then the self-driving assembly can be driven to move by the medium flowing in the control valve group and the gate valve, so that the gate plate of the gate valve is driven to be opened or closed, and the possibility of breaking the gate plate is greatly reduced.

In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a gate valve driven with an internal medium according to an embodiment of the present utility model;

FIG. 2 is a schematic illustration of a gate valve according to an embodiment of the present utility model in a first control position;

fig. 3 is a schematic view of a gate valve according to an embodiment of the utility model in a second control position.

Icon: 10-a valve body assembly; 11-cylinder barrel; 111-upper cylinder; 1110-a second connection hole; 112-lower cylinder; 1120—a first connection hole; 12-a valve cover; 13-a cavity; 14-a support table; 131-valve cavity; 132-piston chamber; 2-flashboard component; 20-flashboard sleeve; 21-flashboard; 22-springs; 23-anti-rotation keys; 24-valve stem; 3-a self-driving assembly; 30-a piston member; 31-pretensioning; 32-an upper stroke valve core; 33-downstroke spool; 40-a boost solenoid valve; 41-a pressure relief solenoid valve; 5-position indication means; 6-locking device.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, apparatus, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent after an understanding of the present disclosure. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but rather, obvious variations may be made upon an understanding of the present disclosure, other than operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided solely to illustrate some of the many possible ways of implementing the methods, devices, and/or systems described herein that will be apparent after a review of the disclosure of the present application.

In the entire specification, when an element (such as a layer, region or substrate) is described as being "on", "connected to", "bonded to", "over" or "covering" another element, it may be directly "on", "connected to", "bonded to", "over" or "covering" another element or there may be one or more other elements interposed therebetween. In contrast, when an element is referred to as being "directly on," directly connected to, "or" directly coupled to, "another element, directly on," or "directly covering" the other element, there may be no other element intervening therebetween.

As used herein, the term "and/or" includes any one of the listed items of interest and any combination of any two or more.

Although terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first member, component, region, layer or section discussed in examples described herein could also be termed a second member, component, region, layer or section without departing from the teachings of the examples.

For ease of description, spatially relative terms such as "above … …," "upper," "below … …," and "lower" may be used herein to describe one element's relationship to another element as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to another element would then be oriented "below" or "lower" relative to the other element. Thus, the term "above … …" includes both orientations "above … …" and "below … …" depending on the spatial orientation of the device. The device may also be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. Singular forms also are intended to include plural forms unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" are intended to specify the presence of stated features, integers, operations, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, operations, elements, and/or groups thereof.

Variations from the shapes of the illustrations as a result, of manufacturing techniques and/or tolerances, are to be expected. Accordingly, the examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shapes that occur during manufacture.

The features of the examples described herein may be combined in various ways that will be apparent after an understanding of the disclosure of the present application. Further, while the examples described herein have a variety of configurations, other configurations are possible as will be apparent after an understanding of the present disclosure.

As shown in fig. 1 to 3, the gate valve of the present embodiment driven by an internal medium is formed with a main body, and includes: valve body assembly 10, flashboard assembly 2, self-driven assembly 3, control valve group etc. Hereinafter, the specific structure of the above-described portions of the gate valve driven by the internal medium according to the present utility model will be described in detail.

In the present embodiment, as shown in fig. 1, the main body includes a valve body assembly 10, a cylinder 11, and a valve cover 12, which are sequentially connected such that the main body is formed in a cylinder-like structure having an axis, and a cavity 13 of a gate valve, which is a cavity for circulation of a medium and movement of each assembly described below, is formed inside the main body. In addition, the cavity 13 is also formed into a cylinder-like structure similar to the main body, and the axis of the cavity 13 coincides with the axis of the main body, so that the stability and consistency of the whole structure of the gate valve are facilitated. In the present embodiment, the cylinder 11 includes an upper cylinder 111 and a lower cylinder 112 connected to each other, and the upper cylinder 111 is connected to the valve cover 12, and the lower cylinder 112 is connected to the valve body assembly 10. Further, the upper cylinder 111 and the valve cover 12 and the lower cylinder 112 and the valve body assembly 10 are integrally formed, and the upper cylinder 111 and the lower cylinder 112 are detachably connected through a flange, a sealing gasket and other connecting pieces, so that the sealing performance of the cavity 13 is ensured, and the installation, the maintenance and the like of each assembly in the cavity 13 can be facilitated. Preferably, a wedge seal is employed between the upper cylinder 111 and the lower cylinder 112 in order to increase the tightness of the cavity 13.

It is to be further noted that the length and the like of the upper cylinder 111 and the lower cylinder 112 at the position where they are connected are not particularly limited as long as the above-described technical effects can be achieved. Similarly, the valve body assembly 10, the valve cover 12, and the chamber 13 are not fixed in size, and should be integrated according to practical situations, such as the flow rate of the circuit medium.

In addition, in the present embodiment, as shown in fig. 1 to 3, a support table 14 is provided at a middle position in the longitudinal direction of the cylinder tube 11, the support table 14 is formed in an annular structure extending toward the axis of the main body, and by this support table 14, the technical effect of controlling the opening and closing of the shutter 21 by the flow of the medium can be more advantageously achieved. Specifically, the support table 14 is formed on the inner wall of the upper cylinder 111, and the through hole of the support table 14 is fitted with the valve stem 24 described below to facilitate axial movement of the valve stem 24. Along the length direction of the main body, the supporting table 14 divides the cavity 13 into a first sub-cavity (i.e. the valve cavity 131) and a second sub-cavity (i.e. the piston cavity 132), and the valve cavity 131 is located at one side close to the valve body assembly 10, so that the accuracy of controlling the medium flow by the control valve set described below can be increased, and the condition that the flashboard 21 is worn or broken due to too high medium flow rate can be avoided.

In the present embodiment, as shown in fig. 1 to 3, a shutter assembly 2 is located in the valve chamber 131 described above, and the shutter assembly 2 includes the shutter housing 20, the shutter 21, the valve stem 24, and the like. Specifically, the shutter housing 20 is formed with a through hole for connecting the shutter 21 in a direction perpendicular to the axis of the main body; while the side of the shutter sleeve 20 adjacent to the valve cover 12 is formed with a recess for corresponding connection of the valve stem 24. In the present embodiment, the number of the shutters 21 is set to two, and the two shutters 21 are symmetrically disposed about the axis of the main body. Furthermore, the sides of the two shutters 21 facing each other are each formed with a corresponding recess in which a compression spring 22 having a rectangular cross section is provided, so that the shutters 21 can be contracted inward (i.e., contracted in the direction of the main body axis) at the moment of opening or during closing of the gate valve, thereby reducing friction resistance during opening and closing of the gate valve and damage to the sealing member during opening and closing, and also enabling the shutters 21 to maintain a reliable seal under the combined action of the spring force of the spring 22 and the medium pressure after closing of the gate valve. In order to ensure the stability of the connection of the shutter housing 20 to the shutter 21, an anti-rotation key 23 is also provided between the two.

Further, the valve stem 24 is formed in a cylinder-like structure having an axis, and the axis of the valve stem 24 coincides with the axis of the main body. As shown in fig. 1 to 3, the lower end of the valve stem 24 in the present embodiment is provided with a first screw thread by which connection of the valve stem 24 with the above-described shutter housing 20 can be achieved. And a conical round table is formed at the transition position of the first thread and the rod body of the valve rod 24, and the conical surface of the round table faces the valve cover 12, namely, the large-diameter end of the round table is attached to the flashboard sleeve 20, so that the structure can play a certain limiting role on the flashboard sleeve 20 to prevent the flashboard sleeve 20 and the flashboard 21 from moving. In addition, the valve stem 24 extends into the piston chamber 132 through the through hole of the support table 14, a shoulder structure and a second screw thread are formed at the upper end of the valve stem 24 and a circular counter bore is also formed at the top of the valve stem 24 so as to be correspondingly connected to the self-driving assembly 3 described below.

In the present embodiment, the self-driving assembly 3 is located in the piston chamber 132, which includes the piston member 30 and the pretensioning member 31, and both the piston member 30 and the pretensioning member 31 are connected to the valve stem 24 by the above-described second screw thread. The end of the piston member 30 adjacent to the valve cover 12 is formed with a groove for correspondingly placing the pretension member 31 so as to fix the piston member 30; in addition, the valve stem 24 is formed with a shoulder corresponding to the end face of the piston member 30 adjacent the support table 14 to further secure the piston member 30. In addition, the self-driving assembly 3 further comprises an upper stroke valve core 32 and a lower stroke valve core 33, wherein a counter bore corresponding to the counter bore at the top end of the valve rod 24 is formed at the top end of the pre-tightening piece 31 so as to be convenient for connecting the upper stroke valve core 32; the lower valve element 33 is disposed at the end of the support table 14 facing the valve cover 12, and the lower valve element 33 is engaged with the piston member 30 when the gate valve is in the closed state.

More specifically, although not shown in the drawings, the side portion of the piston member 30 is formed with a plurality of annular grooves for mounting piston rings by which the stability of the piston member 30 when moved by the medium can be further increased. The piston ring is formed as a metal ring having a rectangular cross section, and each piston ring is formed with a stepped opening. In addition, the pre-tightening member 31 is composed of a main nut and a plurality of pushing screws, that is, a plurality of threaded through holes are machined at the axial end of the main nut, and a plurality of pushing screws are correspondingly installed in the threaded through holes, the actual tensioning force of the connection between the main nut and the valve rod 24 is realized through the pushing screws, and after the pushing screws are pre-tightened, the main nut cannot be loosened. After the main nut is connected to the valve stem 24 by the second thread, the piston member 30 is restrained between the shoulder of the valve stem 24 and the main nut. In addition, a support washer is provided between the piston member 30 and the main nut.

Furthermore, in the present embodiment, a control valve group is further provided in communication with the above-mentioned cavity 13, the control valve group having a first control position and a second control position, and when it is in the first control position, the control valve group is capable of controlling the flow of medium to drive the self-driving assembly 3 to move downward (move in a direction approaching the valve body assembly 10), thereby closing the shutter assembly 2; when in the second control position, the valve block is capable of controlling the flow of medium to drive the upward movement (in a direction approaching the valve cap 12) from the drive assembly 3, thereby opening the shutter assembly 2. In order to achieve the above technical effect, as shown in fig. 1 to 3, the lower cylinder tube 112 and the upper cylinder tube 111 are formed with a first connection hole 1120 and a second connection hole 1110, respectively, and the first connection hole 1120 and the second connection hole 1110 can communicate with the valve chamber 131 and the piston chamber 132, respectively.

In addition, the control valve group includes a pressurizing solenoid valve 40 and a depressurizing solenoid valve 41 connected in sequence. Specifically, the first connection hole 1120 communicates with the inlet of the pressurizing solenoid valve 40, and the second connection hole 1110 communicates with the position where the pressurizing solenoid valve 40 and the pressure relief solenoid valve 41 are connected, i.e., the second connection hole 1110 communicates with the outlet of the pressurizing solenoid valve 40 and the inlet of the pressure relief solenoid valve 41 at the same time.

Specifically, in the initial state, as shown in fig. 3, the shutter plate assembly 2 is at the lowermost end of the gate valve under the action of gravity, and the shutter plate 21 is abutted against the both-end valve body assembly 10 under the action of the spring 22. When the system pipeline is filled with working medium, the pressure relief electromagnetic valve 41 is electrified and opened (the pressure boost electromagnetic valve 40 is in a power-off state), and the piston cavity 132 is communicated with a system drainage tank (not shown) through the downstroke valve core 33; the medium entering the valve cavity 131 acts on the valve rod 24 and the section of the flashboard 21, the flashboard 21 is retracted towards the center of the flashboard sleeve 20 under the action of the medium force, and meanwhile, the valve rod 24 drives the flashboard assembly 2 to open upwards under the action of the medium force until the valve rod 24 stops moving after the valve rod 24 is closed and sealed with the cylinder 11, so that the medium in the cavity 13 cannot leak from a gap between the valve rod 24 and the cylinder 11. At the same time, the upstroke valve element 32 can be used as a locking lever into the locking device 6 described below and trigger the position indication device 5, and thus a valve-emitting signal can be sent to the control room. Since the valve rod 24 is closed and sealed with the cylinder 11 and the medium in the upper stroke valve closing cavity 13 enters the channel of the self-driving assembly 3, the pressure relief electromagnetic valve 41 is closed at this time, no pressurizing channel exists in the upper cavity of the self-driving assembly 3 (i.e. the piston cavity 132 positioned on the side of the self-driving assembly 3 close to the valve cover 12), and the upper stroke valve rod 24 is locked, so that the gate valve can be kept in an open state all the time.

When the gate valve needs to be closed, firstly, an unlocking signal is given to the locking device 6 to be used for electrifying and opening the booster electromagnetic valve 40 (the pressure relief electromagnetic valve 41 is in a power-off state), then a medium from a system pipeline enters an upper cavity of the self-driving assembly 3 through the booster electromagnetic valve 40, the medium can push the self-driving assembly 3 to act downwards, meanwhile, the upper stroke valve core 32 is opened, and the inner cavity of the gate plate sleeve 20 is communicated with the upper cavity of the self-driving assembly 3. Since the self-driving assembly 3 is in a downward movement state, the pressure of the upper cavity of the self-driving assembly 3 in the state is about 1/5 of the pressure in the cavity 13 (obtained by multiple experiments and calculation), and is far lower than the pressure of a system pipeline, the pressure in the gate plate assembly 2 is discharged to the self-driving assembly 3, the gate plate 21 is contracted towards the gate plate sleeve 20 under the action of the medium pressure in the cavity 13, the contracted gate plate assembly 2 moves downwards along with the self-driving assembly 3, when the piston member 30 moves to the lowest end, the lower forming valve is closed, the piston member 30 stops moving, the pressure in the upper cavity of the self-driving assembly 3 and the pressure in the gate plate assembly 2 are gradually increased to be equal to the pressure in the system pipeline, and the gate plate 21 is ejected away from the center of the gate plate sleeve 20 under the action of the elastic force of the spring 22, so that the gate valve outlet end valve body assembly 10 is closed, the pressure of the medium in the cavity 13 acts on the gate plate, and the gate plate 21 is kept in a closed and reliable sealing state. If the pressurizing electromagnetic valve 40 is powered off at this time, the medium in the system loop is cut off, but because the medium in the cavity 13 can enter the upper cavity of the self-driving assembly 3 through the central hole of the valve rod 24, the medium in the upper cavity of the self-driving assembly 3 is closed by the pressure relief electromagnetic valve 41, namely, the pressure in the self-driving assembly 3 is the same as the pressure in the cavity 13, so that the gate valve can be reliably closed for a long time.

Furthermore, the gate valve is also connected with a position indicating device 5 and a locking device 6, wherein the locking device 6 extends into the cavity 13 and is connected with the valve rod 24, and the position indicating device 5 is connected with the locking device 6.

According to the gate valve driven by the internal medium, the self-driving assembly 3 is connected with the valve rod 24 in the cavity 13, and then the self-driving assembly 3 can be driven to move by the medium flowing in the control valve group and the gate valve, so that the gate plate 21 of the gate valve is driven to be opened or closed, and the possibility of breaking the gate plate 21 is greatly reduced. The valve is opened and closed by the pressure of the medium, when the valve has larger drift diameter, the valve can be opened and closed only by controlling the medium by two small electromagnetic valves, the reliability is high, and the risks of clamping stagnation, rebound when the flashboard 21 is closed, non-tight closing and the like in the opening and closing process of the valve are eliminated. The flashboard 21 is not contacted with the valve body assembly 10 in the whole opening or closing process, so that the abrasion of the flashboard 21 and the sealing surface of the valve body assembly 10 is reduced, the medium force exerted on the flashboard 21 by the medium is eliminated, and the service life of each part in the gate valve is effectively prolonged. In addition, compared with the traditional electric gate valve, the gate valve has short response time and high action speed, and can cut off media rapidly especially when special working conditions occur, so that the safety guarantee of the system is greatly improved.

Finally, it should be noted that: the foregoing examples are merely specific embodiments of the present application, and are not intended to limit the scope of the present application, but the present application is not limited thereto, and those skilled in the art will appreciate that while the foregoing examples are described in detail, the present application is not limited thereto. Any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or make equivalent substitutions for some of the technical features within the technical scope of the disclosure of the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A gate valve driven by an internal medium, formed with a body, the body comprising:

2. The gate valve driven by an internal medium according to claim 1, wherein the main body includes a valve body assembly, a cylinder, and a valve cover, which are sequentially connected to form the main body into a cylinder-like shape having an axis; a support table is formed at a middle position in the length direction of the cylinder barrel, and the support table is formed into an annular structure extending toward the axis of the main body.

3. The gate valve driven by an internal medium according to claim 2, wherein the support table divides the cavity into a first subchamber and a second subchamber along a length direction of the main body, and the first subchamber is located near a side of the valve body assembly; the shutter assembly is located in the first subchamber and the self-driven assembly is located in the second subchamber.

4. A gate valve driven with an internal medium according to claim 3, wherein the axis of the valve stem coincides with the axis of the body and the valve stem extends into the second subchamber; the through hole of the supporting table is matched with the valve rod.

5. The gate valve driven by an internal medium according to claim 2, wherein the self-driving assembly comprises a piston member and a pre-tightening member, the piston member and the pre-tightening member being connected to each other and each being sleeved on an end of the valve stem adjacent to the valve cover; the end part of the piston part, which is close to the valve cover, is provided with a groove, and the pre-tightening part is arranged in the groove.

6. The gate valve driven with an internal medium according to claim 5, wherein the self-driving assembly further comprises an upper stroke spool and a lower stroke spool; the upper stroke valve core is connected with the end part of the valve rod, which is close to the valve cover; the downstroke valve core is arranged on the end face of the supporting table, which faces the valve cover, and when the main body is in a closed state, the downstroke valve core is attached to the piston piece.

7. A gate valve driven by an internal medium according to claim 3, wherein the cylinder is formed with a first connection hole and a second connection hole, which communicate with the first subchamber and the second subchamber, respectively; the first connecting hole and the second connecting hole are connected with the control valve group.

8. The gate valve driven by an internal medium according to claim 7, wherein the control valve group includes a pressurizing solenoid valve and a depressurizing solenoid valve connected in sequence, the first connection hole communicates with an inlet of the pressurizing solenoid valve, and the second connection hole communicates with a position where the pressurizing solenoid valve and the depressurizing solenoid valve are connected; when the control valve group is in a first control position, the pressurizing electromagnetic valve works, and the pressure relief electromagnetic valve does not work; when the control valve group is in the second control position, the pressure relief electromagnetic valve works, and the pressure boosting electromagnetic valve does not work.

9. The gate valve driven with an internal medium according to claim 2, wherein the gate assembly comprises a gate sleeve, the valve stem being connected to a side of the gate sleeve adjacent the valve cover; the flashboard is connected to the inside of the flashboard sleeve, and an anti-rotation key is arranged between the flashboard sleeve and the flashboard; the number of the flashboard is two, and the two flashboards are symmetrically arranged about the axis of the main body; the sides of the two shutters facing each other are each formed with a recess in which a spring is provided.

10. The gate valve driven by an internal medium according to claim 1, wherein the gate valve driven by an internal medium is further provided with a position indication means and a locking means, the locking means extending into the cavity and being connected to the valve stem, the position indication means being connected to the locking means.