CN105545858B - A kind of special Pneumatic valve of pneumohydraulic pressure-cylinder and pneumohydraulic pressure-cylinder - Google Patents

Abstract

The invention discloses a special air-controlled valve for a gas-liquid pressurized cylinder, which includes a valve disc, a valve core and a limit copper block; The upper part of the inner cavity section is provided with a disc control air hole communicating with the inner cavity, and the lower part of the inner cavity section is opened with a valve disc working air hole communicated with the inner cavity; the valve core includes an upper piston, a lower piston, and an upper piston. The effective active area is smaller than that of the lower piston, and the upper piston is always in sealing contact with the inner wall of the inner cavity during the working process. The invention also discloses a gas-liquid pressurized cylinder, which includes a rear end cover and the above-mentioned air control valve. A through hole is opened on the rear end cover. The holes are arranged sequentially from top to bottom. The air control valve in the present invention can brake and open after the hydraulic piston rod of the booster cylinder touches the workpiece, realizing the automatic conversion of the booster cylinder from the fast-forward pre-pressing stroke to the booster punching stroke, which is safe and reliable.

Description

A special air control valve for air-liquid booster cylinder and air-liquid booster cylinder

technical field

The invention relates to a booster cylinder, in particular to a special air control valve for a gas-liquid booster cylinder and a gas-liquid booster cylinder.

Background technique

The gas-liquid booster cylinder is widely used in stamping equipment and other occasions that require a large thrust. The built-in special air control valve of the gas-liquid booster cylinder is the control component that controls the booster cylinder from the fast-forward pre-pressing stroke to the booster punching stroke. .

Patent ZL200810019120.0 discloses an air-operated valve, which includes a valve body, a valve core slidably arranged in the inner cavity of the valve body, a front end cover and a rear end cover respectively sealingly fitted at both ends of the valve body, and the valve body There are fluid inlets and outlets respectively on the two opposite side walls, air holes are respectively opened on the front end cover and the rear end cover, the valve core has a first end, a second end and a closing part that can block the outlet, the first The end, the second end and the closing part are respectively sealed and matched with the inner wall of the valve body. The first section, the valve body and the front end cover form the first air chamber, and the second end, the valve body and the rear end cover form the first air chamber. The second air chamber, the closing part, the second end and the valve body form the third air chamber, the first air chamber, the second air chamber and the third air chamber are mutually sealed, and the first air chamber passes through the front end cover. The air hole is connected with the reset air path, and the second air chamber is connected with the control air path through the air hole on the rear end cover. The pressure of the gas in the reset air path is kept constant, and the area of the front surface of the first end is smaller than that of the second end. The area of the rear end surface of the part, the inlet and outlet are staggered in the axial direction of the valve core, when the valve is closed, the closing part is blocked on the outlet, and the inlet is connected with the third air chamber, when the valve is opened, the closing part allows When the outlet is opened, the third air chamber forms a passage with the inlet and the outlet, so that the gas can flow through. This kind of air control valve has the following defects: 1), short service life and air leakage; 2), no sealing ring is provided, only relying on gap sealing, it is difficult to disassemble, once a problem occurs, it is difficult to repair, greatly shortening the entire booster cylinder 3), due to the limitation of the special structure of the gas-liquid booster cylinder, the above-mentioned air control valve cannot meet the needs of the gas-liquid booster cylinder. The above defects are also common problems in the existing air control valves.

This shows that the prior art needs to be further improved and improved.

Contents of the invention

In order to avoid the disadvantages of the above-mentioned prior art, the present invention provides a special air control valve for a gas-liquid booster cylinder and a gas-liquid booster cylinder. Automatically open after the workpiece to realize the automatic conversion of the booster cylinder from the fast-forward pre-pressing stroke to the booster punching stroke, which is safe and reliable.

The technical scheme adopted in the present invention is:

A special air control valve for a gas-liquid pressurized cylinder, including a valve disc, a valve core and a limit copper block arranged sequentially from top to bottom; Fixed connection, the bottom end of the inner cavity section is open, the inner cavity section is provided with an inner cavity for the valve core to move back and forth, the upper part of the inner cavity section is provided with a disc control air hole communicating with the inner cavity, and the lower part of the inner cavity section is opened. There is a disc working air hole connected to the inner cavity; the valve core includes the upper piston, the lower piston and the piston rod connecting the upper and lower pistons. The effective area of the upper piston is smaller than that of the lower piston. During the working process, the upper piston is always in contact with the The inner wall of the inner chamber is in sealing contact, and the outer diameter of the lower piston is larger than the inner diameter of the inner chamber.

Gray rings are arranged between the top end surface of the upper piston and the inner wall of the inner cavity and between the bottom end surface of the upper piston and the inner wall of the inner cavity.

A first limiting boss is arranged at the central position of the bottom end surface of the base body segment, and a second limiting boss is arranged at the central position of the top end surface of the limiting copper block.

The invention also discloses a gas-liquid pressurized cylinder, which includes a rear end cover and the above-mentioned air control valve. The rear end cover is provided with a through hole for installing a valve disc, a valve core and a limit copper block. The valve disc, valve core and limit copper block are sequentially arranged in the through hole from top to bottom.

O-rings are arranged between the base body section, the middle part of the inner cavity section and the lower part of the inner cavity section and the inner wall of the through hole.

An O-ring is arranged between the lower piston and the inner wall of the through hole.

An O-ring is arranged between the limiting copper block and the inner wall of the through hole.

The outer diameter of the base section is greater than that of the inner cavity section, and the through hole, the lower end surface of the base section and the upper end surface of the O-ring in the middle of the inner cavity section cooperate to form an upper piston control chamber, and the valve disc controls The air hole communicates with the control chamber of the upper piston; the through hole, the lower end surface of the O-ring in the middle of the inner cavity section and the upper end surface of the O-ring in the lower part of the inner cavity section cooperate to form a disc cavity, and the valve disc working air hole It communicates with the disc chamber; the through hole, the lower end surface of the O-ring at the lower part of the inner cavity section and the upper end surface of the lower piston cooperate to form a lower piston control chamber; the rear end cover is sequentially opened with The upper piston control air hole, the cylinder air hole, the air source air hole and the lower piston control air hole, wherein the upper piston control air hole communicates with the upper piston control chamber, the cylinder air hole communicates with the disc chamber, the air source air hole communicates with the lower piston control chamber, and the lower piston The control air hole communicates with the gap between the lower end surface of the lower piston and the top end surface of the limit copper block.

The air-operated valve has two positions, which are respectively the preparation position and the working position. From the preparation position to the working position is the process stage of the valve core, and returning from the working position to the standby position is the return journey of the valve core. stage; when preparing for the machine position, the upper piston is in sealing contact with the entrance of the inner cavity, the lower piston is limited by the limit copper block, and the gas from the control gas source passes through the upper piston control air hole and the valve flap control air hole to the top surface of the upper piston, and the outer The air passes through the air source air hole and the lower piston control chamber to the top surface of the lower piston; when the working machine is in position, the upper piston moves to the first limiting boss and is limited by the first limiting boss, and the valve disc working air hole passes through The inner cavity and the lower piston control chamber are connected with the air source air hole, that is, the valve disc working air hole is connected with the external atmosphere, and the bottom end surface of the lower piston is connected with the control air source through the lower piston control chamber and the lower piston control air hole, and the air source is controlled at the same time. The gas passes through the upper piston control air hole and the disc control air hole to the top surface of the upper piston; when the valve core returns, the lower piston connects to the external atmosphere through the lower piston control chamber and the air source air hole, and the upper piston connects to the control air source, and the valve core returns. This goes back and forth.

The pressurized cylinder also includes an air circuit system, which includes a return air intake channel, a fast air intake channel, a pressurized air intake channel, a control air source, an external atmosphere, an external two-position five-way valve and a built-in The air control valve, the air control valve is a two-position three-way valve; three of the interfaces of the two-position five-way valve are respectively connected with the return air intake channel, the fast air intake channel and the control air source through pipelines, and the two-position The remaining ports of the five-way valve are connected to the external atmosphere. The two-position five-way valve has two positions, one is to control the air source to communicate with the return air intake channel, and at the same time, the rapid air intake channel is connected to the external atmosphere, and the other is to control The air source communicates with the fast air intake channel, while the return air intake channel communicates with the external atmosphere; the interface of the two-position three-way valve communicates with the rapid air intake channel, the pressurized air intake channel, and the external atmosphere through pipelines, and the two-position three-way valve is connected to the external atmosphere. The one-way valve has two control terminals, which are the control I terminal and the control II terminal respectively. The air intake channel is connected with the external atmosphere, the fast air intake channel is connected with the control terminal I of the two-position three-way valve through a pipeline, the return air intake channel is connected with the control II terminal of the two-position three-way valve through a pipeline, and the return air intake channel is connected with the control terminal II of the two-position three-way valve. A one-way throttle valve is arranged on the pipeline between the control II ends.

Owing to adopting above-mentioned technical scheme, the beneficial effect that the present invention obtains is:

1. The air control valve in the present invention adopts an asymmetric spool design. When the pressurized cylinder is in the ready state, the gas controlling the gas source communicates with the piston end of the piston on the spool through the air circuit, pushing the spool to the initial position. When the pressurized cylinder is in the fast-forward pre-compression stroke, the hydraulic piston rod in the cylinder is pushed by the gas to move to the workpiece at a relatively fast speed. At this time, the volume of the working chamber becomes larger. The lower piston end of the spool is connected, but because the volume of the working chamber becomes larger, the internal pressure has not reached the working pressure, so the lower piston end of the air control valve cannot be pushed to open. When the pressurized cylinder is in the pressurized stroke, since the hydraulic piston rod has been attached to the workpiece, the internal volume of the working chamber is fixed, so when the internal pressure reaches the working pressure, even though the piston on the valve core is still connected with the control air source, but due to The asymmetric design of the valve core can still open stably, the control gas reaches the lower piston end of the valve core through the air path and pushes the valve core until the upper piston end of the valve core fits with the first limit boss inside the disc. When the air control valve is opened, the working gas enters the cylinder air hole of the rear end cover of the booster cylinder through the working air hole of the disc, and the working gas enters the cylinder of the booster cylinder, pushing the piston rod of the cylinder down to complete the booster stroke. When the pressurized cylinder returns to the stroke, the external air source hole connected to the original working chamber is controlled by the external two-position five-way valve to communicate with the external atmosphere. At this time, the working chamber and the piston end of the lower piston of the valve core are connected to the external atmosphere, while The return working gas pushes the hydraulic piston rod back to the ready stroke, the cylinder piston rod is controlled by the spring to return to the ready stroke, and the piston end of the piston on the spool communicates with the control air pressure to push the spool back to the ready stroke. The invention makes full use of the principle of force balance, because the piston end of the lower piston of the valve core communicates with the fast air inlet hole of the working chamber, and the piston end of the upper piston of the valve core always communicates with the control air source, so that the work of the valve core is more stable. To prevent the hydraulic piston rod from being opened before the workpiece is attached to the air control valve, that is to avoid the disorder of the fast-forward pre-pressing stroke and the boosting punching stroke.

2. The air control valve in the present invention can brake and open after the hydraulic piston rod of the booster cylinder touches the workpiece, realizing the automatic conversion of the booster cylinder from the fast-forward pre-pressing stroke to the booster punching stroke, which is safe, reliable and stable high sex.

3. In the present invention, the disc of the air-operated valve and the limit copper block are provided with O-shaped sealing rings, which realize the sealing between the valve disc, the limit copper block and the through hole of the booster cylinder, replacing the previous gap The sealed form is convenient for installation, maintenance and experimentation, and avoids damage to the through hole due to processing and installation.

4. The present invention has simple structure, convenient installation and maintenance, and low production cost, and is suitable for wide application.

Description of drawings

Fig. 1 is a structural schematic diagram of a valve clack in the present invention.

Fig. 2 is a structural schematic diagram of the valve core in the present invention.

Fig. 3 is a schematic diagram of the structure of the limiting copper block in the present invention.

Fig. 4 is a schematic diagram of the state of the air control valve in the ready position of the present invention.

Fig. 5 is a schematic diagram of the working position of the air control valve in the present invention.

Fig. 6 is a schematic diagram of the relative positional relationship between the rear end cover of the booster cylinder and the air control valve in the ready position state in the present invention.

Fig. 7 is a schematic diagram of the relative position relationship between the rear end cover of the booster cylinder and the air control valve in the working position state in the present invention.

Fig. 8 is a diagram of the gas circuit system of the pressurized cylinder in the present invention.

in,

1. Base section 2, O-ring seal 3, first limit boss 4, inner chamber 5, disc control air hole 6, valve disc working air hole 7, gray ring 8, piston rod 9, inner cavity section 10, Upper piston 11, lower piston 12, limit copper block 13, second limit boss 14, rear end cover 15, upper piston control air hole 16, cylinder air hole 17, air source air hole 18, lower piston control air hole 19, upper piston Control chamber 20, disc chamber 21, lower piston control chamber 22, two-position five-way valve 23, one-way throttle valve 24, two-position three-way valve 25, rapid intake passage 26, return intake passage 27, booster Intake channel

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, but the present invention is not limited to these embodiments.

As shown in Figures 1 to 3, an air-operated valve dedicated to a gas-liquid pressurized cylinder includes a valve disc, a valve core and a limit copper block 12 arranged sequentially from top to bottom; the valve disc includes a base section 1 and an inner Chamber segment 9, the top of the inner cavity segment 9 is fixedly connected with the base body segment 1, the bottom end of the inner cavity segment 9 is open, and the inner cavity segment 9 is provided with an inner cavity 4 for the valve core to move back and forth, and the upper part of the inner cavity segment 9 There is a disc control air hole 5 communicating with the inner cavity 4, and the lower part of the inner cavity section 9 is provided with a valve disc working air hole 6 communicating with the inner cavity 4; The piston rod 8, the effective area of the upper piston 10 is smaller than the effective area of the lower piston 11, the upper piston 10 is always in sealing contact with the inner wall of the inner cavity 4 during the working process, and the top surface of the upper piston 10 is in contact with the inner wall of the inner cavity 4 Between and between the bottom end surface of the upper piston 10 and the inner wall of the inner cavity 4, a gray ring 7 is arranged, and the outer diameter of the lower piston 11 is greater than the inner diameter of the inner cavity 4; at the central position of the bottom end surface of the base segment 1 A first limiting boss 3 for limiting the upper piston 10 is provided, and a second limiting boss 13 for limiting the lower piston 11 is provided at the center of the top end surface of the limiting copper block 12 .

As shown in Figures 1 to 7, the present invention also discloses a gas-liquid pressurized cylinder, which includes a rear end cover 14 and the above-mentioned air control valve, and the rear end cover 14 is provided with valve clacks, valves, etc. The through hole of the core and the limit copper block 12, the valve disc, the valve core and the limit copper block 12 are sequentially arranged in the through hole from top to bottom; the base segment 1, the middle part of the inner cavity segment 9 and the inner cavity An O-ring seal 2 is arranged between the bottom of the section 9 and the inner wall of the through hole, an O-ring 2 is arranged between the lower piston 11 and the inner wall of the through hole, and the limiting copper block 12 is connected to the inner wall of the through hole. O-rings 2 are arranged between the inner walls of the through holes.

The outer diameter of the base section 1 is greater than the outer diameter of the inner cavity section 9, and the through hole, the lower end surface of the base section 1 and the upper end surface of the O-ring 2 in the middle of the inner cavity section 9 cooperate to form an upper piston control Cavity 19, the disc control air hole 6 communicates with the upper piston control chamber 19; the through hole, the lower end surface of the O-ring 2 in the middle of the inner cavity section 9 and the upper end surface of the O-ring 2 at the lower part of the inner cavity section 9 Cooperate between them to form a valve disc chamber 20, and the valve disc working air hole 6 communicates with the valve disc chamber 20; the through hole, the lower end surface of the O-shaped sealing ring 2 at the bottom of the inner cavity section 9 and the upper end surface of the lower piston 11 cooperate The lower piston control cavity 21 is formed; the rear end cover 14 is sequentially provided with an upper piston control air hole 15, a cylinder air hole 16, an air source air hole 17 and a lower piston control air hole 18, wherein the upper piston control air hole 15 is connected with the upper piston control air hole. The piston control chamber 19 communicates, the cylinder air hole 16 communicates with the disc chamber 20, the air source air hole 17 communicates with the lower piston control chamber 21, and the lower piston control air hole 18 communicates with the lower end surface of the lower piston 11 and the top surface of the limit copper block 12. gaps between them.

The air-operated valve has two positions, which are respectively the preparation position and the working position. From the preparation position to the working position is the process stage of the valve core, and returning from the working position to the standby position is the return journey of the valve core. stage; as shown in Figure 6, when preparing the machine position, the upper piston 10 is in sealing contact with the entrance of the inner cavity 4, the lower piston 11 is limited by the limit copper block 12, and the gas of the control gas source passes through the upper piston to control the air hole 15, the valve The valve control air hole 5 leads to the top surface of the upper piston 10, and the external atmosphere passes through the air source air hole 17 and the lower piston control chamber 21 to the top end surface of the lower piston 11; as shown in Figure 7, when the working position, the upper piston 10 moves to The position of the first limiting boss 3 is limited by the first limiting boss 3, the disc working air hole 6 communicates with the air source air hole 17 through the inner cavity 4, the lower piston control chamber 21, that is, the valve disc working air hole 6 and The external atmosphere is connected, the bottom end surface of the lower piston 11 is connected with the control air source through the lower piston control chamber 21 and the lower piston control air hole 18, and the gas from the control air source is passed to the upper piston through the upper piston control air hole 15 and the valve disc control air hole 5 The top surface of 10; when the spool returns, the lower piston 11 communicates with the external atmosphere through the lower piston control chamber 21 and the air source air hole 17, and the upper piston 10 communicates with the control air source, and the spool returns to reciprocate.

When the pressurized cylinder is in the fast-forward pre-compression stroke, the hydraulic piston rod in the cylinder is pushed by the gas to move to the workpiece at a relatively fast speed. At this time, the volume of the working chamber becomes larger. The lower piston 11 of the spool is connected, but because the volume of the working chamber becomes larger, the internal pressure has not reached the working pressure, so the lower piston end of the air control valve cannot be pushed to open. When the pressurized cylinder is in the pressurized stroke, since the hydraulic piston rod has been attached to the workpiece, the internal volume of the working chamber is fixed, so when the internal pressure reaches the working pressure, even though the piston 10 on the spool is still connected with the control air source, but Due to the asymmetric design of the spool, it can still be opened stably, and the control gas reaches the lower piston end of the spool through the air path and pushes the spool until the upper piston end of the spool fits with the first limiting boss 3 inside the disc. At this time, the air control valve is opened, and the working gas enters the cylinder air hole 16 of the rear end cover of the booster cylinder through the disc working air hole 6, and the working gas enters the cylinder of the booster cylinder, pushing the piston rod of the cylinder down to complete the booster stroke . When the pressurized cylinder returns to the stroke, the external air source hole connected to the original working chamber is controlled by the external two-position five-way valve 22 to communicate with the external atmosphere. At this time, the working chamber and the piston end of the lower piston 11 of the valve core are both connected to the external atmosphere. , and the return working gas pushes the hydraulic piston rod back to the ready state stroke, the cylinder piston rod is controlled by the spring to return to the ready state stroke, and the piston end of the piston 10 on the spool communicates with the control air pressure to push the spool back to the ready stroke.

The pressurized cylinder also includes an air circuit system. The air circuit system is mainly to complete the rapid approach to the workpiece stroke, the air control valve pressure maintenance and the rapid return after the stamping is completed. There are various combinations. The following is given Kind of embodiment:

As shown in Figure 8, the gas system includes a return air intake passage 26, a rapid intake passage 25, a pressurized intake passage 27, a control air source, an external atmosphere, an external two-position five-way valve 22 and a built-in air intake passage as described above. The above air control valve, the air control valve is a two-position three-way valve 24; three of the ports of the two-position five-way valve 22 communicate with the return air intake passage 26, the fast air intake passage 25 and the control air source through pipelines , the remaining interfaces of the two-position five-way valve 22 are connected with the external atmosphere. The other is to control the air source to communicate with the fast intake passage 25, while the return intake passage 26 communicates with the outside atmosphere; the interface of the two-position three-way valve 24 is connected to the rapid intake passage 25, the pressurized The air intake channel 27 communicates with the external atmosphere. The two-position three-way valve 24 has two control terminals, namely the control I terminal and the control II terminal. The two-position three-way valve 24 has two machine positions, one is the fast air intake channel 25 is communicated with supercharging air intake passage 27, and another kind is that supercharging air intake passage 27 communicates with external atmosphere, and fast air intake passage 25 links to each other with the control I end of two-position three-way valve 24 by pipeline, and return air intake passage 26 The pipeline is connected with the control II end of the two-position three-way valve 24, and the pipeline between the return intake passage 26 and the control II end is provided with a one-way throttle valve 23, and the setting of the one-way throttle valve 23 is to maintain The pressure at the control terminal II of the two-position three-way valve 24, when the hydraulic piston rod fast-forwards close to the workpiece, the gas pressure in the working chamber will soon approach the pressure of the air source, and the gas will reach the two-position three-way valve 24 through the pipeline At this time, both ends of the two-position three-way valve 24 are the air source pressure. Since the area of the control I end, which is the upper piston end, is smaller than the control II end, which is the end area of the lower piston end, the two-position three-way Valve 24 is open.

Working steps of the present invention are:

1), preparation stroke: the machine position of the two-position five-way valve 22 is to control the air source to communicate with the return air intake channel 26 and the rapid air intake channel 25 to communicate with the external atmosphere, and to control the source gas to enter the return journey through the two-position five-way valve 22 The air intake channel 26 stabilizes the hydraulic piston rod at the initial position. At the same time, the gas in the return intake passage 26 enters the control II end (ie, the upper piston end) of the two-position three-way valve 24 through the air path, so that the pressurized intake passage 27 communicates with the external atmosphere. Now the machine position of the two-position three-way valve 24 is the initial position, that is, the ready machine position, as shown in Figure 4 .

2), fast-forward stroke: the machine position of the two-position five-way valve 22 is to control the air source to communicate with the fast air intake passage 25 and the return air intake passage 26 to communicate with the external atmosphere, and to control the air source gas to push the hydraulic piston rod until it contacts the to-be-processed At the same time, the gas in the fast air intake passage 25 reaches the control I end (i.e. the lower piston end) of the built-in two-position three-way valve 24 through the pipeline, but at this time, because the working chamber of the hydraulic piston rod is constantly increasing, the internal pressure does not change. The working pressure has not been reached, so the gas pressure at the lower piston end of the air control valve does not push the valve core at this time, and the position of the two-position three-way valve 24 is still the initial position, that is, the ready position, as shown in Figure 4.

3) Power-increasing stroke; after the hydraulic piston rod touches the processed parts, the volume inside the working cylinder remains constant, and the internal air pressure quickly approaches the air source air pressure. 25 communicates with the pressurized intake passage 27, and the gas in the fast intake passage 25 enters the pressurized intake passage 27, and the cylinder pressurized piston rod is pressed down to achieve the purpose of supercharging. Now the machine position of the two-position three-way valve 24 is the open position, that is, the working machine position, as shown in Figure 5.

4), return stroke: pressurized air intake channel 27 is communicated with the external atmosphere, the control gas source is communicated with the return air intake channel 26 and the fast intake channel 25 is communicated with the external atmosphere, and the control gas source gas enters from the return air intake channel 26 The hydraulic piston rod returns to the initial position, and the return spring makes the booster cylinder piston return to the initial position. Now the machine position of the two-position three-way valve 24 is the initial position, that is, the ready machine position, as shown in Figure 4 .

The parts not mentioned in the present invention can be realized by adopting or referring to the prior art.

In addition, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (5)

1. A gas-liquid booster cylinder, characterized in that it includes a rear end cover and a special air control valve for the gas-liquid booster cylinder, and the special gas control valve for the gas-liquid booster cylinder includes sequentially arranged from top to bottom The valve disc, valve core and limit copper block; the valve disc includes a base section and an inner cavity section, the top of the inner cavity section is fixedly connected with the base section, the bottom end of the inner cavity section is open, and a supply valve is opened on the inner cavity section The inner cavity where the core moves back and forth, the upper part of the inner cavity section is provided with a disc control air hole communicating with the inner cavity, and the lower part of the inner cavity section is opened with a valve disc working air hole communicated with the inner cavity; the valve core includes an upper piston, a lower piston and The piston rod connecting the upper and lower pistons, the effective area of the upper piston is smaller than the effective area of the lower piston, the upper piston is always in sealing contact with the inner wall of the inner cavity during the working process, and the outer diameter of the lower piston is greater than the inner diameter of the inner cavity; The central position of the bottom end surface of the base section is provided with a first limiting boss, and the central position of the top surface of the limiting copper block is provided with a second limiting boss; the rear end cover is provided with a , the through hole of the valve core and the limit copper block, the valve disc, the valve core and the limit copper block are arranged sequentially from top to bottom in the through hole; the base section, the middle part of the inner cavity section and the inner cavity section An O-ring is arranged between the lower part and the inner wall of the through hole; the outer diameter of the base section is larger than the outer diameter of the inner cavity section, and the O ring in the through hole, the lower end surface of the base section, and the middle part of the inner cavity section The upper end faces of the O-shaped sealing rings cooperate to form the upper piston control chamber, and the disc control air hole communicates with the upper piston control chamber; the through hole, the lower end face of the O-ring in the middle of the inner chamber section, and the O The upper end surfaces of the O-shaped sealing rings cooperate to form a valve disc cavity, and the valve disc working air holes communicate with the valve disc cavity; A lower piston control chamber is formed; the rear end cover is sequentially provided with an upper piston control air hole, a cylinder air hole, an air source air hole and a lower piston control air hole from top to bottom, wherein the upper piston control air hole communicates with the upper piston control chamber, and the cylinder air hole It communicates with the disc chamber, the gas source air hole communicates with the lower piston control chamber, and the lower piston control air hole communicates with the lower end surface of the lower piston and the gap between the top surface of the limit copper block. 2. A gas-liquid pressurized cylinder according to claim 1, characterized in that an O-ring is provided between the lower piston and the inner wall of the through hole. 3 . The gas-liquid pressurized cylinder according to claim 1 , wherein an O-ring is arranged between the limiting copper block and the inner wall of the through hole. 4 . 4. A gas-liquid pressurized cylinder according to claim 1, characterized in that, the air control valve has two machine positions, respectively a standby machine position and a working machine position, from the standby machine position to the working machine position The position is the process stage of the spool, and the return from the working machine position to the ready machine position is the return stage of the spool; when the machine is ready, the upper piston is in sealing contact with the entrance of the inner cavity, and the lower piston is limited by the limit copper block to control The gas from the air source is passed to the top surface of the upper piston through the upper piston control hole and the disc control hole, and the external atmosphere is passed to the top surface of the lower piston through the air source hole and the lower piston control chamber; when the machine is in working position, the upper piston moves to the first At a limiting boss and limited by the first limiting boss, the working air hole of the valve disc is connected with the air source air hole through the inner cavity and the lower piston control chamber, that is, the working air hole of the valve disc communicates with the external atmosphere, and the bottom of the lower piston The end surface communicates with the control air source through the lower piston control cavity and the lower piston control air hole, and the gas from the control air source passes through the upper piston control air hole and the disc control air hole to the top surface of the upper piston; when the valve core returns, the lower piston passes through the lower piston. The piston control chamber and the gas source air hole are connected to the external atmosphere, the upper piston is connected to the control gas source, and the valve core is returned, so as to reciprocate. 5. A gas-liquid pressurized cylinder according to claim 4, characterized in that, the pressurized cylinder also includes an air circuit system, and the air circuit system includes a return air intake passage, a fast air intake passage, a pressurized intake air Air channel, control air source, external atmosphere, external two-position five-way valve and built-in air control valve as described above, the air control valve is a two-position three-way valve; three of the two-position five-way valves The interface is respectively connected with the return air intake passage, the quick air intake passage and the control air source through the pipeline, and the remaining interfaces of the two-position five-way valve are connected with the external atmosphere. The two-position five-way valve has two positions, one is the control air source It communicates with the return air intake channel, while the fast air intake channel communicates with the external atmosphere, and the other is that the control air source communicates with the fast air intake channel, and at the same time, the return air intake channel communicates with the external atmosphere; the interface of the two-position three-way valve The two-position three-way valve has two control terminals, namely the control I terminal and the control II terminal, and the two-position three-way valve has two machine positions. One is that the fast intake channel communicates with the pressurized intake channel, and the other is that the pressurized intake channel communicates with the external atmosphere. The fast intake channel is connected with the control I end of the two-position three-way valve through a pipeline, and the return process is carried out. The air channel is connected to the control II end of the two-position three-way valve through a pipeline, and a one-way throttle valve is arranged on the pipeline between the return air intake channel and the control II end.