CN212377382U

CN212377382U - Modular mechanical pipeline gas self-closing valve

Info

Publication number: CN212377382U
Application number: CN202020224278.8U
Authority: CN
Inventors: 吴万荣
Original assignee: Zhejiang Jufan Copper Co ltd
Current assignee: Zhejiang Jufan Copper Co ltd
Priority date: 2020-02-28
Filing date: 2020-02-28
Publication date: 2021-01-19
Anticipated expiration: 2030-02-28

Abstract

A modular mechanical pipeline gas self-closing valve is provided with a control cavity body which is connected with the gas outlet end of a manual ball valve and is communicated with each other, and the gas outlet end of the control cavity body is provided with a gas connecting hose for external threads. The utility model discloses a modular mechanical pipeline gas self-closing valve can self-close the air supply when appearing under-pressure, overflowing, the superpressure, can solve various gas leakage problems effectively in the modular mechanical pipeline gas self-closing valve of the utility model discloses a modular mechanical pipeline gas self-closing valve can be when appearing the air supply of can closing automatically when under-pressure, overflowing, the superpressure.

Description

Modular mechanical pipeline gas self-closing valve

Technical Field

The utility model relates to a modular mechanical pipeline gas relief valve. In particular to a modular mechanical pipeline gas self-closing valve.

Background

In order to solve the problem of environmental pollution, clean energy is widely popularized at present, industrial and agricultural and civil fuels are widely popularized to carry out coal-to-gas engineering, because combustible gas is flammable and explosive gas, relevant regulations, standards and precautionary measures are established by the government in order to guarantee the gas safety of gas users, and therefore engineering technicians in the industry propose different technical schemes.

In order to prevent the problem of gas leakage, the gas self-closing valve on the market at present basically adopts a permanent magnet as the power for automatic control, the constant and unchangeable attraction force of the permanent magnet is highlighted in practical application, the application range of working condition is limited, when the gas consumption peak is reached, the gas source can be automatically cut off when the gas pressure is reduced to a critical point, the illusion of general gas stopping is caused, the gas user and a gas company are mostly unchanged, and the gas self-closing valve can be inevitably eliminated because the design is not suitable for the change of the working condition. In order to solve this problem, the design scheme is changed according to the actual applicable conditions.

Chinese utility model patent ZL2015207576467.9 provides a pipeline gas self-closing valve, the last port at the main valve body gas storage storehouse is provided with the involucra, the involucra is along with the atmospheric pressure change inflation in the gas storage storehouse or return the shifting block up-and-down motion that contracts and drive and set up in the gas storage storehouse, axial motion is made to the internal valve plate of control main valve, keep the valve plate in the state of opening when gas pressure is balanced, can the automatic cutout air supply when pressure is less than standard state, when appearing the flow too big involucra and contract to the minimum, the valve plate will the automatic cutout air supply. When the gas storage bin is applied in an aging mode, the shifting block arranged in the gas storage bin is limited by the overturning angle and cannot automatically close a gas source under overpressure, and the lack of an overpressure automatic closing function cannot meet the relevant standard requirements. Another kind of utility model patent ZL201720173658.1 provides a pipeline gas self-closing valve, sets up a sleeve at the center of the main valve body gas storage storehouse, and the sleeve both ends are connected and are set up and lead the wall, lead and set up the guiding hole on the wall. The guide hole is crossed with the sleeve of the sleeve and the main valve body and is communicated with the sleeve of the main valve body, a normally open valve plate is arranged in the air outlet channel of the air inlet end of the main valve body, a guide shaft of the normally open valve plate penetrates through the sleeve into which the guide hole enters, the normally closed valve plate is arranged at the port of the air outlet channel of the main valve body, and the guide shaft of the normally closed valve plate penetrates through the sleeve into which the guide hole enters. The normally closed valve plate and the normally open valve plate are controlled by a tapered pull rod arranged in the sleeve, when the pull rod is pulled upwards, the conical surface of the pull rod pushes the normally closed valve plate to conduct a gas channel, and a film arranged at the upper port of the main valve body expands by gas pressure to keep the normally closed valve plate to conduct a gas source under normal working conditions. When the air pressure in the main valve body air storage bin is lower than the rated pressure, the leather membrane at the upper port of the main valve body retracts to drive the pull rod to synchronously fall back to be separated from the normally closed valve plate to close the air source.

When the air flow is larger than the rated range, the leather membrane retracts to drive the pull rod to synchronously fall back to be separated from the normally closed valve plate to close the air source. When the air pressure in the air storage bin is higher than the rated pressure, the leather membrane continues to expand to drive the pull rod to continue to rise to push the long-open valve plate to close the air outlet channel, so that the pipeline gas self-closing valve can automatically close the gas source under overpressure, underpressure and overcurrent. Because the normally closed valve plate is still in an open state after overpressure is closed, gas still exists in the gas storage bin, so that the gas source cannot be completely closed. Therefore, another design solution to solve the disadvantages is required. Another kind of utility model patent ZL201821645121.1 has given a mechanical type pipeline gas self-closing valve again, and the central accuse support that sets up in the main valve body gas storage storehouse, the configuration starts the support in the well accuse support, starts to establish in the support very heavy, and the pull rod is linked on the top of starting the support, and the pull rod is controlled by main valve body upper port involucra, sets up into the air control valve version in the gas passage of main valve body gas storage storehouse and ball valve. Lifting the pull rod upwards to start the jack in the support to open the air inlet control valve plate to conduct the air source, and expanding the leather membrane to keep the air inlet control valve plate open for ventilation. When the air pressure in the air storage bin is lower than the standard, the leather membrane retracts to drive the starting support to descend, and the jack is separated from the air inlet control valve plate to close the air source. When the air pressure in the air storage bin is larger than the standard, the leather membrane continues to expand to drive the starting support to continuously rise so that the jack is separated from the air inlet control valve plate to close the air source, the leather membrane retracts when the air storage bin loses pressure and returns to a static state, and when the air flow is larger than a rated range, the leather membrane retracts to drive the pull rod to synchronously fall back to separate from the normally closed valve plate to close the air source, so that the effective function of automatically closing the air source under overpressure, underpressure and overcurrent is realized. Although some drawbacks of several kinds of gas pipeline self-closing valves have been solved to this kind of design, nevertheless because structure, technology are complicated, because the pull rod is threaded connection with the start support, and the port involucra is elastic material, and with this sealing connection of pull rod, the pull rod produces the skew, can drive the start support and can produce the skew in the guide bracket, makes and starts to produce the interference between support and the guide bracket, and gas pressure belongs to the low pressure, only at 1 ~ 3KPa, so can not guarantee the starting support and reciprocate do not have the interference flexibility. Therefore, a reliable pipeline gas self-closing valve is needed to be designed through further improvement. Because governments place importance on the safety of gas and relevant regulations and preventive measures, technicians in the industry have proposed various solutions.

Disclosure of Invention

The utility model aims to solve the technical problem that a multiple functional, simple and easy modular, safe and reliable more, durable is provided to modular mechanical pipeline gas self-closing valve that links into an integrated entity with the gas ball valve.

The utility model adopts the technical proposal that: the utility model provides a modular mechanical pipeline gas self-closing valve, by ball valve switch with have the superpressure, under-voltage, overflow the leak protection gas automatic control device of overflowing constitute, wherein, ball valve switch include: the automatic air leakage prevention control device is arranged on the air outlet side of the ball valve cavity and comprises a control cavity with an air inlet end integrally connected to the air outlet side of the ball valve cavity, an air outlet nozzle thread for connecting an external gas hose is formed at the air outlet end of the control cavity, a leather diaphragm which is used for sealing the control cavity and can be driven by gas in the control cavity to bulge or collapse upwards is arranged at the upper end opening of the control cavity, the upper end of the pull rod penetrates through the arc-shaped upper cover and is connected with a manual pulling adjusting mechanism which is used for manually pulling the pull rod to move upwards and adjusting the moving degree of the pull rod to move upwards, a central control bracket is fixedly arranged in the control cavity, an air inlet control valve starting mechanism which can drive the air inlet control valve to open or close an air outlet of the ball valve cavity by moving up and down along the central control bracket is arranged in the central control bracket, and the top end of the air inlet control valve starting mechanism is movably connected to the lower end of the pull rod.

The utility model discloses a modular mechanical pipeline gas self-closing valve, two modules of automatic control mechanism integration with the dispersion, two modules are synthetic automatic control mechanism of a correlation again, and the production assembly process is simplified in the interrelatedness between every accessories, and the self-closing action is sensitive reliable, accurate, consequently safe and reliable more. The utility model has the advantages of the following.

1. The utility model discloses set up the control cavity at the end of giving vent to anger of ordinary ball valve, set up the modular automatic control mechanism that has superpressure, under-voltage, overflows in the control cavity, solved various gas leakage problems effectively, especially because of pipeline maintenance or when a great deal of reason stops gas, can the self-closing air supply, because of not closing the gas valve when preventing to resume the air feed and leaking the problem that the gas causes the disaster accident.

2. The utility model discloses well manual ball valve and automatic control device though set up respectively on ball valve cavity and control cavity, because ball valve and control cavity structure as an organic whole to interrelatedly, thereby eliminate the hidden danger of multiple spot connection on gas pipeline, safe and reliable more.

3. Because the pull rod is in non-rigid connection with the starting support, when the pull rod deviates, the central position of the starting support can be automatically adjusted, so that the starting support is prevented from interfering with the guide support, and the starting support always keeps non-interference movement in the guide support.

Drawings

FIG. 1 is a schematic diagram of the external structure of a modular mechanical pipeline gas self-closing valve of the present invention;

FIG. 2 is a schematic view of the internal structure of a modular mechanical pipeline gas self-closing valve of the present invention;

FIG. 3 is a schematic view of the exploded structure of the modular mechanical pipeline gas self-closing valve of the present invention;

FIG. 4 is a top view of the ball valve portion and control chamber portion of the present invention;

FIG. 5 is a cross-sectional view A-A of FIG. 4;

fig. 6 is a schematic structural view of the central control bracket of the present invention;

FIG. 7 is a schematic structural view of the connection between the central control bracket and the air inlet control valve;

fig. 8 is a schematic structural diagram of a pi-shaped frame of the starting mechanism of the air intake control valve according to the present invention;

FIG. 9 is a schematic structural view of the Pi-shaped frame of the starting mechanism of the air inlet control valve of the present invention connected with a jack;

fig. 10 is a schematic structural view of the jack of the present invention;

fig. 11 is a schematic structural view of the middle pull rod of the present invention;

fig. 12 is a schematic structural diagram of the adjusting gland of the present invention.

In the drawings

1: and (3) a ball valve cavity 2: ball switch

3: air inlet threaded interface 4: manual knob mechanism

5: intake control valve 6: control cavity

7: the air outlet nozzle thread 8: central control support

8.1: bottom plate 8.2: supporting plate

8.3: guide post 8.4: guide hole

8.5: u-shaped plate 8.6: guide groove

8.7: lug 8.8: through hole

9: air outlet 10: air inlet control valve starting mechanism

10.1: n-shaped frame 10.2: u-shaped groove

10.3: through hole 10.4: cross beam

11: pull rod 11.1: main rod body

11.2: sealing disc 11.3: external thread

11.4: connecting groove 12: touch shaft

13: coating 14: circular arc upper cover

15: control spring 16: shaft clamp spring

17: support boss 18: screw hole

19: jack 19.1: arc end face

19.2: opening 19.3: shaft hole

20: the jack shaft 21: torsion spring

22: the tray 23: nut cap

24: upper spring 25: adjusting gland

25.1: lower adjustment gland 25.2: upper connecting cylinder

25.3: the limiting convex edge 26: limit pull button

26.1: the hook 27 is: inner pull button

Detailed Description

The following detailed description of the modular mechanical pipeline gas self-closing valve of the present invention is made with reference to the following embodiments and accompanying drawings.

As shown in fig. 1, fig. 2 and fig. 3, the utility model discloses a modular mechanical pipeline gas self-closing valve, by ball valve switch with have the superpressure, the leak protection gas automatic control device that is under-voltage, overflows constitutes, wherein, ball valve switch include: a ball valve cavity 1 with an air inlet and an air outlet which are communicated with each other and formed on two sides, a ball switch 2 arranged in the ball valve cavity 1, a manual knob mechanism 4 which is arranged on the top end of the ball valve cavity 1 and connected with the ball switch 2 and is used for switching on or off the ball valve cavity 1 by manually controlling the rotation of the ball switch 2, and an air inlet screw thread interface 3 connected with the air inlet of the ball valve cavity 1, wherein an air inlet control valve 5 which is controlled by an air leakage prevention automatic control device to open or close the air outlet 9 is arranged at the air outlet 9 of the ball valve cavity 1, the air leakage prevention automatic control device is arranged at the air outlet side of the ball valve cavity 1 and comprises a control cavity 6 with an air inlet end integrally connected with the air outlet side of the ball valve cavity 1, and an air outlet end of the control cavity 6 is formed with an air outlet screw thread 7 used, a membrane 13 which is used for sealing the control cavity 6 and can be upwards expanded or collapsed under the driving of gas in the control cavity 6 is arranged at the upper port of the control cavity 6, and an arc-shaped upper cover 14 for fixing the coating 13, wherein a pull rod 11 is arranged at the center of the coating 13 in a vertically penetrating manner, the lower end of the pull rod 11 is positioned in the control cavity 6, the upper end of the pull rod 11 penetrates through the arc-shaped upper cover 14 and is connected with a manual pulling adjusting mechanism which is used for manually pulling the pull rod 11 to move upwards and can adjust the upward moving degree of the pull rod 11, a central control bracket 8 is fixedly arranged in the control cavity 6, an air inlet control valve starting mechanism 10 which can drive the air inlet control valve 5 to open or close the air outlet 9 of the ball valve cavity 1 by moving up and down along the central control bracket 8 is arranged in the central control bracket 8, the top end of the air intake control valve actuating mechanism 10 is movably connected to the lower end of the pull rod 11.

As shown in fig. 6 and 7, the central control bracket 8 includes a bottom plate 8.1, a vertically arranged support plate 8.2 is integrally formed at one end of the bottom plate 8.1, a guide post 8.3 is arranged on the support plate 8.2, a guide hole 8.4 capable of penetrating through a touch shaft 12 on the air intake control valve 5 for guiding the movement of the touch shaft 12 is axially formed at the center of the guide post 8.3, a circle of groove is formed at the front end of the touch shaft 12, after the front end of the touch shaft 12 passes through the guide hole 8.4, as shown in fig. 2 and 6, a control spring 15 is firstly sleeved, an upper shaft snap spring 16 is further arranged in the groove at the front end of the touch shaft 12 for limiting the air intake control valve 5 from being pulled out of the guide hole 8.4, one end of the control spring 15 acts on the guide post 8.3, and the other end acts on the shaft snap spring 16. The rubber valve plate of the air inlet control valve 5 is blocked at the air outlet 9 of the ball valve cavity 1, and a normally closed switch for blocking the air outlet 9 is formed under the action of the control spring 15. A guide groove 8.6 formed by symmetrically arranging two U-shaped plates 8.5 is integrally formed on the bottom plate 8.1 corresponding to the guide column 8.3, the air inlet control valve starting mechanism 10 is installed in the guide groove 8.6 and guides the vertical movement of the air inlet control valve starting mechanism 10, and the air inlet control valve starting mechanism 10 can move up and down in the guide groove 8.6 without interference.

The outer side surfaces of the two U-shaped plates 8.5 are respectively provided with a lug 8.7 for fixedly connecting with a support boss 17 formed in the control cavity 6 as shown in fig. 4 and 5, and a through hole 8.8 for connecting with a screw hole 18 on the support boss 17 through a bolt is formed on the lug 8.7.

As shown in fig. 8 and 9, the intake control valve actuating mechanism 10 includes an n-shaped frame 10.1, a U-shaped groove 10.2 for connecting the lower end of the pull rod 11 is formed on a horizontal plate at the top of the n-shaped frame 10.1, through holes 10.3 are correspondingly formed on two vertical plates of the n-shaped frame 10.1, the lower portions of the two vertical plates of the n-shaped frame 10.1, which are far away from the through holes 10.3, are connected through a cross beam 10.4, and a jack 19 for touching a touch shaft 12 on the intake control valve 5 is arranged in the n-shaped frame 10.1 through a jack shaft 20 penetrating through the through holes 10.3 of the two vertical plates.

As shown in fig. 9 and 10, the jack 19 is of an n-shaped strip structure, one end of the n-shaped strip is formed with an arc end surface 19.1 for touching the touch shaft 12 on the air intake control valve 5, the other end of the n-shaped strip is an opening 19.2, two side surfaces of the n-shaped strip are correspondingly provided with shaft holes 19.3 at positions close to the opening 19.2, the jack shaft 20 penetrates through two ends of the shaft hole 19.3 and is respectively inserted into the through holes 10.3 at two sides of the n-shaped frame 10.1, the jack shaft 20 at the inner side of the jack 19 is sleeved with a torsion spring 21, one end of the torsion spring 21 is respectively arranged on the inner top surface of the jack 19, the other end of the torsion spring is respectively arranged on the cross beam 10.4, and the arc end surface 19.1 of the jack 19 is arranged opposite to the touch shaft 12 on the air intake control valve 5 supported on the central control frame 8.

As shown in fig. 11, the device comprises a main rod body 11.1, a sealing disc 11.2 is integrally formed on the main rod body 11.1 near the lower end of the main rod body 11.1 and is used for being in sealing contact with the membrane 13, an external thread 11.3 used for being connected with a manual pulling adjusting mechanism is formed on the main rod body 11.1 at the upper part of the sealing disc 11.2, and a circle of connecting groove 11.4 used for being movably connected with a U-shaped air control groove 10.2 at the upper end of the air inlet valve actuating mechanism 10 is formed on the main rod body 11.1 at the lower part of the sealing disc 11.2.

As shown in fig. 2 and 3, a tray 22 for sealing a gap between the coating film 13 and the tie rod 11 is fitted over the upper end surface of the coating film 13 of the tie rod 11, and is compacted by a nut 23 screwed to the tie rod 11. The upper part and the lower part of the through hole in the middle of the membrane 8 and the pull rod 11 form a sealed state, so that the membrane 8 drives the pull rod 11 to move up and down when expanding or retracting under the gas pressure in the control cavity 6, the pull rod 11 also drives the air inlet control valve starting mechanism 10 to move up and down by moving up and down, the jack 19 touches the touch shaft 12 on the air inlet control valve 5 in the moving process, and the air inlet control valve 5 opens or closes the air outlet 9 of the ball valve cavity 1.

As shown in fig. 2, 3 and 12, the manual pull-up adjusting mechanism includes: the lower part of the adjusting gland 25 is connected to the inner side of the top opening of the circular arc-shaped upper cover 14, the upper part of the adjusting gland 25 is connected to the inner side of the limit pull button 26 which is communicated up and down, the lower vertical part of the adjusting gland 25 is inserted into the inner side of the upper part of the adjusting gland and is connected with the inner pull button 27 on the upper part of the pull rod 11 through internal threads, the horizontal part of the upper part of the inner pull button 27 is lapped at the upper port of the limit pull button 26, when the limit pull button 26 is pulled up manually, the inner pull button 27 is driven to move up, meanwhile, the inner pull button 27 drives the air inlet control valve starting mechanism 10 to move up through the connected pull rod 11, so that the jack 19 touches the touch shaft 12 on the air inlet control valve 5, the air outlet 9 of the ball valve cavity 1 is.

The pull rod 11 is also sleeved with an upper spring 24, the upper end of the upper spring 24 is propped in a lower adjusting gland 25.1 of the adjusting gland 25, and the lower end of the upper spring is propped on the tray 22.

The adjusting gland 25 is a lower adjusting gland 25.1 which is formed with external threads and is in threaded connection with internal threads of the top opening of the circular arc-shaped upper cover 14, an upper connecting cylinder 25.2 which is integrally connected with the upper end of the lower adjusting gland 25.1, the diameter of which is smaller than that of the lower adjusting gland 25.1 and is provided with steps at the connection part with the lower adjusting gland 25.1, a circle of limiting convex edge 25.3 which protrudes outwards is formed at the upper end opening of the upper connecting cylinder 25.2, a plurality of hooks 26.1 are formed at the lower periphery of the inner side of the limiting pull button 26, and when the limiting pull button 26 moves upwards along the outer side of the upper connecting cylinder 25.2 for a set distance, the limiting convex edge 25.3 and the hooks 26.1 are hooked straight, so that the limiting pull button 26 is prevented from moving upwards continuously and can not be separated from the upper connecting cylinder 25.2.

As shown in fig. 2 and fig. 7, the working principle of the modular mechanical pipeline gas self-closing valve of the present invention is that after the ball switch 2 is opened by the manual knob mechanism 4, the gas entering the ball valve cavity 1 is closed in the gas outlet 9 by the gas inlet control valve 5, at this time, the limit pull button 26 is pulled up to drive the inner pull button 27, the pull rod 11, the gas inlet control valve starting mechanism 10 to ascend synchronously, the upper spring 24 retracts, when the jack 19 in the gas inlet control valve starting mechanism 10 touches the touch shaft 12 on the gas inlet control valve 5, the end of the touch shaft 12 moves horizontally according to the track of the arc end face 19.1 at the front end of the jack 19, the gas inlet control valve 5 moves to the ball valve cavity 1 side to open the gas outlet 9, the gas enters the control cavity 6, the upper spring 24 retracts due to the expansion of the diaphragm 13 under the action of the gas pressure, the diaphragm 13 and the upper spring 24 act to keep the gas pressure in the control cavity 6 balanced within the standard range, keeping the ventilation in a safe state.

When the pressure is smaller than the standard range, the leather diaphragm 13 retracts to the upper spring 24 to open and press the air inlet control valve starting mechanism 10, the pull rod 11 and the inner pull button 27 to move downwards, the jack 19 is separated from the touch shaft 12 on the air control valve 5, the control spring 15 on the touch shaft 12 extends to enable the air control valve 5 to move towards the control cavity 6 to block the air outlet 9, and the air source is closed. The automatic air leakage prevention control device is restored to a static state after the air source is closed.

When the integral output gas flow is larger than the rated flow, the leather membrane 13 retracts, the upper spring 24 opens to enable the pull rod 11 to drive the inner pull button 27 and the air inlet control valve starting mechanism 10 to synchronously move downwards, the jack 19 in the air inlet control valve starting mechanism 10 is separated from the touch shaft 12 on the control valve 5, the control spring 15 on the touch shaft 12 extends to enable the control valve 5 to move towards the control cavity 6 side to block the air outlet 9, and the air source is closed. The automatic air leakage prevention control device is restored to a static state after the air source is closed.

When the gas pressure in the control cavity 6 is larger than the standard range, the membrane 13 continues to expand, the upper spring 24 retracts again to drive the inner pull button 27, the pull rod 11 and the air inlet control valve starting mechanism 10 to move upwards synchronously, the jack 19 in the air inlet control valve starting mechanism 10 is separated from the touch shaft 12 on the control valve 5, the control spring 15 on the touch shaft 12 extends to enable the control valve 5 to move towards the control cavity 6 to block the air outlet 9, and the pressure in the control cavity 6 is relieved. The leather diaphragm 13 retracts, the upper spring 24 opens to enable the pull rod 11 to drive the inner pull button 27 and the air inlet control valve starting mechanism 10 to synchronously move downwards, the lower end face of the jack 19 contacts and is separated from the contact shaft 12, then the lower end face of the jack rotates clockwise to be attached to a cross beam 10.4 in the air inlet control valve starting mechanism 10, and the air leakage prevention automatic control device returns to a static state after an air source is closed.

Therefore, the utility model discloses a modular mechanical pipeline gas self-closing valve just enables leak protection gas automatic control device to restore the quiescent condition of closing the air supply under the condition that normal operating mode switched on the air supply.

The specific embodiments described in the present invention are merely examples of the present invention, and those skilled in the art can make various modifications or additions to the described specific embodiments and substitute them in a similar manner, without departing from the spirit of the present invention or the scope defined by the appended claims.

Claims

1. The utility model provides a modular mechanical pipeline gas self-closing valve, by ball valve switch with have the superpressure, under-voltage, overflow the leak protection gas automatic control device of overflowing constitute, wherein, ball valve switch include: a ball valve cavity (1) with an air inlet and an air outlet which are communicated with each other and formed on two sides, a ball switch (2) arranged in the ball valve cavity (1), a manual knob mechanism (4) which is arranged at the top end of the ball valve cavity (1), is connected with the ball switch (2) and is used for switching on or off the ball valve cavity (1) through the rotation of the manual control ball switch (2), and an air inlet threaded interface (3) connected with the air inlet of the ball valve cavity (1), wherein an air inlet control valve (5) which is controlled by an air leakage prevention automatic control device to open or close the air outlet (9) is arranged at the air outlet (9) of the ball valve cavity (1), the air leakage prevention automatic control device is arranged at the air outlet side of the ball valve cavity (1) and comprises a control cavity (6) with an air inlet end integrally connected with the air outlet side of the ball valve cavity (1), the gas outlet end of the control cavity (6) is provided with a gas outlet nozzle thread (7) used for being connected with an external gas hose, the upper port of the control cavity (6) is provided with a membrane (13) which is used for sealing the control cavity (6) and can be upwards bulged or collapsed under the drive of gas in the control cavity (6), and a circular arc-shaped upper cover (14) used for fixing the membrane (13), the center of the membrane (13) is provided with a pull rod (11) in an up-and-down penetrating manner, the lower end of the pull rod (11) is positioned in the control cavity (6), the upper end of the pull rod (11) penetrates through the circular arc-shaped upper cover (14) and is connected with a manual pulling adjusting mechanism which is used for manually pulling the pull rod (11) to move upwards and can adjust the upward moving degree of the pull rod (11), a central control bracket (8) is fixedly arranged in the control cavity (6), and a gas inlet control valve which can be driven by moving upwards and downwards along the central control bracket (8) is arranged 5) And the air inlet control valve starting mechanism (10) is used for opening or closing the air outlet (9) of the ball valve cavity (1), and the top end of the air inlet control valve starting mechanism (10) is movably connected to the lower end of the pull rod (11).

2. The modular mechanical pipeline gas self-closing valve according to claim 1, the central control bracket (8) comprises a bottom plate (8.1), one end of the bottom plate (8.1) is integrally formed with a vertically arranged support plate (8.2), a guide post (8.3) is arranged on the support plate (8.2), a guide hole (8.4) which can penetrate through a touch shaft (12) on the air inlet control valve (5) and is used for guiding the movement of the touch shaft (12) is formed in the central axial direction of the guide post (8.3), a guide groove (8.6) formed by two U-shaped plates (8.5) symmetrically arranged is integrally formed on the bottom plate (8.1) corresponding to the guide column (8.3), the guide groove (8.6) is provided with the air inlet control valve starting mechanism (10) and guides the vertical movement of the air inlet control valve starting mechanism (10).

3. The modular mechanical pipeline gas self-closing valve as claimed in claim 2, characterized in that two U-shaped plates (8.5) are respectively provided with a lug (8.7) on the outer side for fixedly connecting with a support boss (17) formed in the control cavity (6), and the lug (8.7) is provided with a through hole (8.8) for connecting with a screw hole (18) on the support boss (17) through a bolt.

4. The modular mechanical pipeline gas self-closing valve as claimed in claim 1, wherein the gas inlet control valve actuating mechanism (10) comprises a n-shaped frame (10.1), a U-shaped groove (10.2) for connecting the lower end of the pull rod (11) is formed on a horizontal plate at the top of the n-shaped frame (10.1), through holes (10.3) are correspondingly formed on two vertical plates of the n-shaped frame (10.1), the two vertical plates of the n-shaped frame (10.1) are connected with each other through a cross beam (10.4) at the lower part of one side far away from the through holes (10.3), and a jack (19) for touching a touch shaft (12) on the gas inlet control valve (5) is arranged in the n-shaped frame (10.1) through a jack shaft (20) penetrating through the through holes (10.3) on the two vertical plates.

5. The modular mechanical pipeline gas self-closing valve as claimed in claim 4, wherein the lifting jack (19) is of an n-shaped strip structure, one end of the n-shaped strip is formed with an arc-shaped end surface (19.1) for touching the touch shaft (12) on the gas inlet control valve (5), the other end of the n-shaped strip is provided with an opening (19.2), two side surfaces of the n-shaped strip are correspondingly provided with shaft holes (19.3) at positions close to the opening (19.2), the lifting jack shaft (20) penetrates through two ends of the shaft holes (19.3) and is respectively inserted into the through holes (10.3) at two sides of the n-shaped frame (10.1), a torsion spring (21) is sleeved on the lifting jack shaft (20) positioned at the inner side of the lifting jack (19), one end of the torsion spring (21) is respectively arranged on the inner top surface of the lifting jack (19), the other end of the torsion spring is respectively arranged on the cross beam (10.4), and the arc-shaped end surface (19.1) of the lifting jack (19) is opposite to the touch shaft (12) on the gas inlet control valve (5) supported on the central control bracket (.

6. A modular mechanical pipeline gas self-closing valve as claimed in claim 4, wherein the pull rod (11) comprises a main rod body (11.1), the main rod body (11.1) is integrally formed with a sealing disc (11.2) at a position close to the lower end thereof for being in sealing contact with the membrane (13), an external thread (11.3) for being connected with a manual pulling adjusting mechanism is formed on the main rod body (11.1) at the upper part of the sealing disc (11.2), and a circle of connecting groove (11.4) for being movably connected with a U-shaped groove (10.2) at the upper end of the air inlet control valve actuating mechanism (10) is formed on the main rod body (11.1) at the lower part of the sealing disc (11.2).

7. A modular mechanical gas self-closing valve for pipelines, according to claim 6, characterized in that a tray (22) for sealing the gap between the membrane (13) and the pull rod (11) is sleeved on the upper end face of the membrane (13) on the pull rod (11) and compacted by a nut (23) screwed on the pull rod (11).

8. The modular mechanical pipeline gas self-closing valve as claimed in claim 1, wherein the manual pull-up adjusting mechanism comprises: an adjusting gland (25) with the lower part connected with the inner side of the top opening of the circular arc-shaped upper cover (14) and the upper part connected with the inner side of a limit pull button (26) which is communicated up and down, and an inner knob (27) having a lower vertical portion inserted into an inner side of an upper portion of the adjusting cover (25) and coupled to an upper portion of the draw bar (11) by an internal thread, the horizontal part at the upper part of the inner pull button (27) is lapped at the upper port of the limit pull button (26), when the limiting pull button (26) is pulled upwards manually, the inner pull button (27) is driven to move upwards, meanwhile, the inner pull button (27) drives the starting mechanism (10) of the air inlet control valve to move upwards through the connected pull rod (11), thereby the jack (19) touches the touch shaft (12) on the air inlet control valve (5) and the air inlet control valve (5) opens the air outlet (9) of the ball valve cavity (1) to conduct the air source.

9. The modular mechanical pipeline gas self-closing valve as claimed in claim 8, wherein the adjusting gland (25) is a lower adjusting gland (25.1) which is formed with external threads and is in threaded connection with internal threads of the top opening of the circular arc-shaped upper cover (14), an upper connecting cylinder (25.2) which is integrally connected with the upper end of the lower adjusting gland (25.1), has a diameter smaller than that of the lower adjusting gland (25.1) and is formed with steps at the connection part with the lower adjusting gland (25.1), the upper connecting cylinder (25.2) is formed with a circle of limiting convex edge (25.3) which protrudes outwards at the upper port, the inner lower periphery of the limiting pull button (26) is formed with a plurality of hooks (26.1), and when the limiting pull button (26) moves upwards for a set distance along the outer side of the upper connecting cylinder (25.2), the limiting convex edge (25.3) and the hooks (26.1) are hooked straight, thereby limiting the limit pull button (26) to move upwards continuously and being incapable of falling out of the upper connecting cylinder (25.2).

10. The modular mechanical pipeline gas self-closing valve as claimed in claim 8, wherein the pull rod (11) is further sleeved with an upper spring (24), the upper end of the upper spring (24) is supported in a lower adjusting gland (25.1) of the adjusting gland (25), and the lower end of the upper spring is supported on the tray (22).