System and method for automatically closing valve when pneumatic pipeline is broken and application

Abstract

The invention belongs to the technical field of pneumatic system safety, and discloses a system and method for automatically closing a valve when a pneumatic pipeline is broken and application. The valve comprises a first air capacitor, a double-pneumatic-control reversing valve, a first throttling valve, a first one-way valve, a second one-way valve, a third one-way valve, a second throttling valve, a second air capacitor, a reset button and a third throttling valve, the double-pneumatic-control reversing valve is arranged in the horizontal direction, and the reset button is installed on the horizontal side of the double-pneumatic-control reversing valve. The reset button can reset the working state of the double pneumatic control reversing valve. On the basis of the fluid mechanics principle, the valve element is driven to be closed through the instant high pressure difference caused by flow increase, the whole action process is automatically completed within 0.5 second, electric power or manual operation is not depended on, and reliability is high. Gas in a pipeline can be closed instantly at the initial stage of pipeline breakage, flying power of a hose is eliminated, pumping injury to an operator caused by the hose is fundamentally avoided, meanwhile, the vertical air cylinder is effectively supported, and a load is prevented from being out of control and falling.

Description

Technical Field

[0001] This invention belongs to the field of pneumatic system safety technology, and in particular to an automatic valve shut-off system, method and application for pneumatic pipeline rupture. Background Technology

[0002] In pneumatic technology teaching and industrial applications, pneumatic hoses are key components for connecting various parts and transmitting power. However, due to equipment vibration, aging connectors, improper installation, or operational errors, hoses occasionally detach or break, posing serious safety hazards, mainly in the following two aspects: First, in situations involving frequent operation, such as pneumatic teaching experimental platforms, if the hose ruptures or detaches, the high-pressure gas inside will be released instantly, causing the hose to swing violently and irregularly. Since the hose itself has a certain mass, its end may generate significant impact force during high-speed swinging. If it hits the operator's face, eyes, or other areas, it can easily cause personal injury.

[0003] Secondly, in equipment with vertically mounted cylinders, the rodless chamber of the cylinder is typically used to lift the load. If the hose connecting the rodless chamber suddenly ruptures or detaches during cylinder operation, it will cause a momentary loss of pressure in the rodless chamber, resulting in the load falling uncontrollably. This could not only damage the equipment and workpiece but also pose a serious threat to the safety of personnel on site.

[0004] Currently, there are no dedicated protective devices for pneumatic systems in case of hose detachment or breakage. Therefore, there is an urgent need for a dedicated safety device that can sense the pipeline status in real time and automatically shut off the gas in the pipeline instantly in the event of hose rupture or detachment. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an automatic valve shut-off system, method and application for pneumatic pipeline rupture.

[0006] The technical solution adopted by this invention to solve the problem is: An automatic shut-off valve system for pneumatic pipeline rupture, the valve system comprising a first air reservoir, a dual pneumatically controlled directional valve, a first throttle valve, a first check valve, a second check valve, a third check valve, a second throttle valve, a second air reservoir, a reset button, a third throttle valve, a working port, a pressure port, and an exhaust port, wherein the dual pneumatically controlled directional valve is arranged horizontally, and a reset button is installed on one horizontal side of the dual pneumatically controlled directional valve, the reset button being capable of resetting the working state of the dual pneumatically controlled directional valve.

[0007] Furthermore, the dual pneumatic directional valve is provided with 5 ports, which are respectively configured as a reversing end, an input end, an output end, a reset end, and an exhaust end. The exhaust end is connected to the exhaust port. The reversing end and the reset end are symmetrically arranged in the vertical direction. The input end and the output end are both located at the upper part of the dual pneumatic directional valve, and the exhaust end is located at the lower part of the dual pneumatic directional valve. The reversing end, the input end, the output end, the exhaust end, and the reset end are arranged in sequence in the horizontal direction. The end face areas of the reset end and the reversing end are the same. The reset end is connected to the second gas container, the third check valve, and the second throttle valve. The reset end is connected in parallel with the second gas container and the third check valve, and in series with the second throttle valve. Both the third check valve and the second throttle valve are connected to the working port. The second gas container can store the gas that enters it. The working directions of the third check valve and the second throttle valve are opposite to each other. The third check valve allows gas to be quickly input into the second gas container, and the second throttle valve allows gas to be slowly output from the second gas container. The gas in the second gas container can exert a force on the reversing end of the dual-pneumatic reversing valve. The input end is connected to the pressure port, which can input the gas from the pressure port into the dual-pneumatic reversing valve. The output end is connected to the working port through the third throttle valve, which allows gas to flow out of the dual-pneumatic reversing valve with a certain resistance. The reversing end is connected to the first gas container, the first throttle valve, and the first check valve. The reversing end is connected in parallel with the first gas container and the first check valve. The reversing end is connected in series with the first throttle valve. The first gas container can store the gas that enters it. The working directions of the first throttle valve and the first check valve are opposite to each other. The first check valve can allow the gas in the first gas container to be output quickly. The first throttle valve can allow the gas to be input slowly into the first gas container. The gas in the first gas container can give the dual-pneumatic reversing valve a force towards the reset end. The first throttle valve and the first check valve are both connected to the pressure port of the valve.

[0008] Furthermore, the dual pneumatic directional valve includes a first sealing ring, a second sealing ring, a third sealing ring, a valve core, and a valve body. The valve body has a tubular structure, and the valve core is located inside the valve body. The first sealing ring is located on the valve core between the reversing end and the input end to prevent gas leakage from the input end to the reversing end. The second and third sealing rings are both located on the valve body. The second sealing ring is located between the input end and the output end to prevent gas leakage from the input end when the valve core is in the reset position. The third sealing ring is located between the output end and the exhaust end to prevent gas leakage from the input end to the exhaust end. The reset button can push the valve core to reset the working state of the dual pneumatic directional valve, so that the pressure port and the working port are reconnected.

[0009] The operating method of the pneumatic pipeline rupture automatic valve shut-off system described above includes the following operating steps: 1) When the pressure port is connected to the air source device and the working port is connected to the pneumatic working system, the cylinder does not move. When the gas supply device is turned on, gas enters through the pressure port. The gas cannot pass through the first and second check valves, but it can pass through two paths. One path is through the first throttle valve, where it slowly flows into the first gas container and builds pressure at the reversing end. As time increases, the pressure at the reversing end slowly increases, and under this pressure, a force is applied to the valve core at the reversing end face towards the reset end. The second path is through the valve body's output end, which then flows slowly through the third throttle valve to the working port. Part of the gas at the working port flows out of the valve system to fill the pneumatic working system, while the other part flows rapidly into the second gas container through the third check valve, quickly building pressure at the reset end. Under pressure, the reset end applies a force to the valve core at the reset end face, similar to that applied to the reversing end. Because the reset end and reversing end have the same face area, and the reset end pressure rises faster, at any moment during the pressure rise at both ends, the force on the reversing end is greater than the force on the reset end, thus the valve core remains on the side closer to the reversing end. When the pressure rise process at both ends ends, the gas stops flowing, the pressure at all points inside the valve is the same and equal to the gas source pressure, and the force on the reversing end is equal to the force on the reset end, so the valve core remains on the side closer to the reversing end. Therefore, under condition 1), when the gas source is first turned on, the pressure port and the working port remain connected. 2) Based on condition 1), the pipeline is not ruptured, and the cylinder begins to operate. At the instant the cylinder begins to move, the pressure at the working port drops sharply. However, the gas at the reset end cannot flow from the third check valve to the working port; it can only flow slowly to the working port through the second throttle valve. Therefore, the pressure at the reset end drops slowly. At the same time, due to the sharp drop in working port pressure, the gas at the pressure port flows to the working port through the third throttle valve, causing the pressure at the pressure port to drop. At this moment, the gas at the reversing end flows out rapidly through the first check valve, and the pressure at the reversing end drops instantly to the pressure at the pressure port. Because the reversing end and the reset end of the valve core have the same area, and the pressure at the reset end drops more slowly than that at the reversing end, the force of the valve core towards the reversing end is always greater than the force towards the reset end. The valve core remains on the side closer to the reversing end. Therefore, at the instant the cylinder begins to move, the pressure port and the working port remain connected. After a certain period of time, the cylinder operates stably, and a small flow of gas passes through the third throttle valve. At this time, a stable and small pressure difference is generated across the three ends of the third throttle valve. The reversing end is connected to the pressure port through the first throttle valve, so the pressure at the reversing end and the pressure port remain the same. The reset end is connected to the working port through the second throttle valve, so the pressure at the reset end and the working port remain the same. Therefore, the pressure difference between the reversing end and the reset end is also the pressure difference across the three ends of the third throttle valve. Thus, the resultant force of the gas acting on the valve core is towards the reset end. However, because the pressure difference is small, the resultant force towards the reset end is small. This resultant force cannot overcome the friction generated by the first and third sealing rings, and the valve core remains at the leftmost end. Therefore, the pipeline is not ruptured, and the pressure port and the working port remain connected when the cylinder operates stably. 3) Based on condition 2), the pipeline suddenly ruptures or detaches. If the pipeline at the working port or the pneumatic working system suddenly ruptures or detaches, a large amount of gas will be discharged from the working port. At this time, a large pressure difference will be generated at both ends of the third throttle valve, namely the pressure difference between the reversing end and the reset end. This pressure difference multiplied by the end face area of ​​the valve core is the resultant force of the gas. This resultant force is directed towards the reset end and is greater than the frictional force generated by the first and third sealing rings. It quickly pushes the valve core to the reset end side, relying on the valve core to close the pressure port and prevent gas from flowing out of the working port. After the pressure port is closed, the pressure at the reversing end remains the same as the pressure at the pressure port through the first throttle valve, which is the gas source pressure. The working port is connected to the exhaust port, and the working port pressure drops to 0. The reset end is connected to the working port through the second throttle valve, and the reset end pressure also drops to 0. The resultant force of the gas is still directed towards the reset end side, so the valve core remains on the reset end side. Therefore, when the pipeline suddenly detaches or ruptures, the valve automatically closes, sealing the pressure port. 4) In operating conditions 1), 2), and 3), shut off the gas supply device. Under operating conditions 1) and 2), the valve core is on the reversing end side, and the pressure port and working port are connected. Closing the air supply device causes the gas at the pressure port to be discharged rapidly, and the pressure at the pressure port drops to 0. At this time, the gas at the reversing end is discharged rapidly through the first check valve, and the pressure at the reversing end immediately drops to 0. At the same time, because the pressure at the pressure port drops to 0, the gas at the reset end flows out slowly through the second throttle valve, and the pressure at the reset end drops slowly. Because the pressure at the reset end drops slowly, the force of the valve core towards the reversing end is greater than the force towards the reset end, and the valve core remains on the reversing end side. Therefore, under operating conditions 1) and 2), even when the air supply device is closed, the pressure port and working port are still connected. Under operating condition 3), the valve core is on the reset side, the pressure port is closed, the pressure at the reversing end is the air source pressure, and the pressure at the reset end is 0. Closing the air source device causes the gas at the pressure port to be discharged rapidly, and the pressure at the pressure port drops to 0. At this time, the gas at the reversing end is discharged rapidly through the first check valve, and the pressure at the reversing end immediately drops to 0. Since the pressure at the reset end is also 0, the valve core remains on the reset side. Therefore, under operating condition 3), closing the air source device does not prevent the pressure port from remaining closed. Therefore, under operating condition 4), the gas supply device is shut off, and the valve remains in its original state; 5) With the pressure port and the working port connected, air is introduced through the working port. The valve core is on the reversing end side, and the pressure port and the working port are connected. When gas flows in from the working port, part of the gas flows quickly to the pressure port through the second check valve. The gas in the pressure port flows slowly into the first gas container through the first throttle valve and slowly builds pressure at the reversing end. The other part of the gas in the working port flows quickly into the second gas container through the third check valve and quickly builds pressure at the reset end. Since the pressure is built up more quickly at the reset end, the valve core remains on the reversing end side. Therefore, when the pressure port and the working port are connected, air enters from the working port, and the pressure port and the working port remain connected.

[0010] The application of the system described above in pneumatic teaching experiments.

[0011] The advantages and positive effects of this invention are as follows: 1. The system of the present invention can automatically control and prevent personal injury: The system of the present invention can instantly seal the gas in the pipeline at the initial stage of pipeline rupture, eliminate the force of the hose flying, fundamentally avoid the occurrence of shock injury to the operator, and at the same time provide effective support for the vertical cylinder to prevent the load from falling out of control.

[0012] 2. The system of the present invention can respond quickly without external intervention: The system of the present invention is based on the principle of fluid mechanics and uses the instantaneous high pressure difference caused by the increase in flow to drive the valve core to close. The entire action process is completed automatically within 0.5 seconds, without relying on electricity or manual operation, and has high reliability.

[0013] 3. The system of this invention has a compact structure and is easy to integrate and install: The system of this invention can be directly installed on the port or key pipeline of pneumatic actuators (such as cylinders), requiring minimal modification to existing pneumatic systems, not affecting the original system's operation, and is easy to install, significantly improving the safety level of existing equipment. 4. The system of the present invention can sense the pipeline status in real time and can instantly and automatically seal the pipeline gas when the hose breaks or falls off, thereby improving the pipeline damage monitoring response capability and response speed. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the air circuit of the automatic shut-off valve of the present invention; Figure 2 This is a schematic front sectional view of a structural connection according to the present invention; Figure 3 for Figure 2 A cross-sectional view along the C-C direction; Figure 4 This is a schematic diagram of the gas path in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the gas path in Embodiment 2 of the present invention; Figure 6 This is a photograph of the actual experimental system used in Experimental Test (1) of Example 3; Figure 7 This is a photograph of the actual experimental system used in Experiment Test (2) of Example 3. Detailed Implementation

[0015] The present invention will be further described below with reference to the embodiments. The following embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0016] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0017] A pneumatic pipeline rupture automatic valve shut-off system, such as Figures 1 to 7 As shown, the valve includes a first air container 1, a dual pneumatic directional valve 2, a first throttle valve 3, a first check valve 4, a second check valve 5, a third check valve 6, a second throttle valve 7, a second air container 8, a reset button 9, a third throttle valve 10, a working port A, a pressure port P, and an exhaust port R. The dual pneumatic directional valve 2 is arranged in a horizontal direction, and a reset button 9 is installed on the horizontal side of the dual pneumatic directional valve 2. The reset button 9 can reset the working state of the dual pneumatic directional valve 2. The dual pneumatic control directional valve 2 has 5 ports, which are respectively designated as directional end X, input end Z, output end T, reset end Y, and exhaust end S. The exhaust end S is connected to the exhaust port R. The directional end X and the reset end Y are symmetrically arranged in the vertical direction. The input end Z and the output end T are both located at the upper part of the dual pneumatic control directional valve 2, and the exhaust end S is located at the lower part of the dual pneumatic control directional valve 2. The directional end X, input end Z, output end T, exhaust end S, and reset end Y are arranged sequentially in the horizontal direction. The end face areas of the reset end Y and the directional end X are the same. The reset terminal Y is connected to the second gas container 8, the third check valve 6, and the second throttle valve 7. The reset terminal Y is connected in parallel with the second gas container 8 and the third check valve 6, and in series with the second throttle valve 7. Both the third check valve 6 and the second throttle valve 7 are connected to the working port A. The second gas container 8 can store the gas that enters it. The working directions of the third check valve 6 and the second throttle valve 7 are opposite to each other. The third check valve 6 can allow gas to be quickly input into the second gas container 8, and the second throttle valve 7 can allow the gas in the second gas container 8 to be slowly output. The gas in the second gas container 8 can exert a force on the double-pneumatic reversing valve 2 towards the reversing terminal X. The input terminal Z is connected to the pressure port P and can input the gas from the pressure port P into the double-pneumatic reversing valve 2. The output terminal T is connected to the working port A through the third throttle valve 10. The third throttle valve 10 can allow gas to flow out of the double-pneumatic reversing valve 2 with a certain resistance. The reversing end X is connected to the first gas container 1, the first throttle valve 3, and the first check valve 4. The reversing end X is connected in parallel with the first gas container 1 and the first check valve 4. The reversing end X is connected in series with the first throttle valve 3. The first gas container 1 can store the gas that enters it. The working directions of the first throttle valve 3 and the first check valve 4 are opposite to each other. The first check valve 4 can allow the gas in the first gas container 1 to be output quickly. The first throttle valve 3 can allow the gas to be input slowly into the first gas container 1. The gas in the first gas container 1 can give the dual pneumatic reversing valve 2 a force towards the reset end Y. The first throttle valve 3 and the first check valve 4 are both connected to the pressure port P of the valve.

[0018] Through the design of this structure, especially the first gas container 1, the first throttle valve 3, the first check valve 4, the third check valve 6, the second throttle valve 7, and the second gas container 8, the pressure build-up (or pressure loss) rate of the gas at the switching end X and the reset end Y of the dual pneumatic control directional valve 2 is different. Thus, when the gas pipeline is intact, the valve system can remain open without affecting the normal operation of the original pneumatic system; and when the gas pipeline is ruptured, it can reliably, accurately, and quickly close, sealing the gas in the pipeline.

[0019] In this embodiment, as Figure 2As shown, the dual pneumatic reversing valve 2 includes a first sealing ring 11, a second sealing ring 12-1, a third sealing ring 12-2, a valve core 2-1, and a valve body 2-2. The valve body 2-2 has a tubular structure. The valve core 2-1 is located inside the valve body 2-2. The first sealing ring 11 is located on the valve core 2-1 and between the reversing end X and the input end Z to prevent gas leakage from the input end Z to the reversing end X. The second sealing ring 12-1 and the third sealing ring 12-2 are both located on the valve body 2-2. The second sealing ring 12-1 is located between the input end Z and the output end T to prevent gas leakage from the input end Z when the valve core 2-1 is in the reset end Y. The third sealing ring 12-2 is located between the output end and the exhaust end S to prevent gas leakage from the input end Z from the exhaust end S. The reset button 9 can push the valve core 2-1 to reset the working state of the dual pneumatic reversing valve 2, so that the pressure port P and the working port A are reconnected.

[0020] The working method of the pneumatic pipeline rupture automatic shut-off valve system described above, such as... Figure 2 As shown, the following operating steps are included: (1) When the pressure port P is connected to the air source device for air intake, and the working port A is connected to the pneumatic working system, but the cylinder does not move. When the gas source device is turned on, gas enters through pressure port P. The gas cannot pass through the first check valve 4 and the second check valve 5, but it can pass through two paths. One is that it can slowly flow into the first gas container 1 through the first throttle valve 3 and build up pressure at the reversing end X. As time increases, the pressure at the reversing end X slowly increases. Under the action of pressure, the reversing end X exerts a force on the end face of the reversing end X of the valve core 2-1 in the direction of the reset end Y. The other is that the gas flows through the output end T of the valve body 2-2 and slowly flows to the working port A through the third throttle valve 10. Part of the gas in the working port A flows out of the valve system and fills the pneumatic working system, while the other part of the gas flows quickly into the second gas container 8 through the third check valve 6 and quickly builds up pressure at the reset end Y. Under the action of pressure, the reset end Y exerts a force on the end face of the reset end Y of the valve core 2-1 in the direction of the reversing end X. Because the end face areas of the reset end Y and the reversing end X are the same, and the pressure of the reset end Y rises quickly, at any moment when the reversing end X and the reset end Y are rising, the force of the valve core 2-1 toward the reversing end X is greater than the force toward the reset end Y. Therefore, the valve core 2-1 remains on the side closer to the reversing end X. When the pressure rise process of the reversing end X and the reset end Y ends, the gas stops flowing, the pressure at each point inside the valve is the same and equal to the gas source pressure, the force of the valve core 2-1 toward the reversing end X is equal to the force toward the reset end Y, and the valve core 2-1 remains on the side closer to the reversing end X. Therefore, under operating condition (1), when the gas source is opened for the first time, the pressure port P and the working port A always remain connected.

[0021] (2) Based on the working condition (1), the pipeline is not broken and the cylinder starts to operate. At the instant the cylinder begins to move, the pressure at working port A drops sharply. However, the gas at reset port Y cannot flow from the third check valve 6 to working port A. Instead, it can only flow slowly to working port A through the second throttle valve 7. Therefore, the pressure at reset port Y drops slowly. At the same time, due to the sharp drop in pressure at working port A, the gas at pressure port P flows to working port A through the third throttle valve 10. The pressure at pressure port P will drop. At this time, the gas at reversing port X flows out rapidly through the first check valve 4. The pressure at reversing port X drops instantly to the pressure at pressure port P. Because the reversing port X and reset port Y of valve core 2-1 have the same area, and the pressure drop at reset port Y is slower than that at reversing port X, the force of valve core 2-1 toward reversing port X is always greater than the force toward reset port Y. Valve core 2-1 remains on the side closer to reversing port X. Therefore, at the instant the cylinder begins to move, pressure port P and working port A remain connected. After a certain period of time, the cylinder operates stably, and a small flow of gas passes through the third throttle valve 10. At this time, a stable and small pressure difference (i.e., the pressure at pressure port P minus the pressure at working port A) is generated across the third throttle valve 10. The reversing end X is connected to pressure port P through the first throttle valve 3, so the pressure at the reversing end X and pressure port P remains the same. The reset end Y is connected to working port A through the second throttle valve 7, so the pressure at the reset end Y and working port A remains the same. Therefore, the pressure difference between the reversing end X and the reset end Y is also the pressure difference across the third throttle valve 10. Thus, the resultant force of the gas acting on valve core 2-1 is directed towards the reset end Y. However, because the pressure difference is small, the resultant force towards the reset end Y is small. This resultant force cannot overcome the friction generated by sealing ring 11 and the third sealing ring 12-2, and valve core 2-1 remains at the leftmost end. Therefore, the pipeline is not ruptured, and when the cylinder operates stably, pressure port P and working port A remain connected.

[0022] (3) Based on the operating condition (2), the pipeline suddenly ruptures or falls off. If the pipeline or pneumatic working system pipeline at working port A suddenly ruptures or falls off, a large amount of gas will be discharged from working port A. At this time, a large pressure difference will be generated at both ends of the third throttle valve 10, namely the pressure difference between the reversing end X and the reset end Y. This pressure difference multiplied by the end face area of ​​valve core 2-1 is the resultant force of the gas. This resultant force is directed towards the reset end Y and is very large, greater than the frictional force generated by sealing ring 11 and the third sealing ring 12-2. This force will quickly push valve core 2-1 to the reset end Y side, and the valve core 2-1 will close the pressure port P, preventing the gas from flowing out of working port A. After pressure port P is closed, the pressure at the reversing end X is kept the same as the pressure at pressure port P through the first throttle valve 3, which is the gas source pressure. Meanwhile, the working port A is connected to the exhaust port R, and the pressure at the working port A drops to 0. The reset end Y is connected to the working port A through the second throttle valve 7, and the pressure at the reset end Y also drops to 0. The resultant force of the gas is still towards the reset end Y side, so the valve core 2-1 remains on the reset end Y side. Therefore, when the pipeline suddenly falls off or breaks, the valve automatically closes, sealing the pressure port P.

[0023] (4) In operating conditions (1), (2) and (3), shut off the gas supply device. Under operating conditions (1) and (2), valve core 2-1 is on the reversing end X side, and pressure port P and working port A are connected. Closing the gas source device causes the gas at pressure port P to be discharged rapidly, and the pressure at pressure port P drops to 0. At this time, the gas at reversing end X is discharged rapidly through the first check valve 4, and the pressure at reversing end X immediately drops to 0. At the same time, since the pressure at pressure port P drops to 0, the gas at reset end Y flows out slowly through the second throttle valve 7, and the pressure at reset end Y drops slowly. Since the pressure at reset end Y drops slowly, the force of valve core 2-1 toward reversing end X is greater than the force toward reset end Y, and valve core 2-1 remains on the reversing end X side. Therefore, under operating conditions (1) and (2), when the gas source device is closed, pressure port P and working port A are still connected. Under operating condition (3), valve core 2-1 is on the reset end Y side, pressure port P is closed, the pressure at the reversing end X is the gas source pressure, and the pressure at the reset end Y is 0; closing the gas source device causes the gas at pressure port P to be discharged rapidly, and the pressure at pressure port P drops to 0. At this time, the gas at the reversing end X is discharged rapidly through the first check valve 4, and the pressure at the reversing end X immediately drops to 0; since the pressure at the reset end Y is also 0, valve core 2-1 remains on the reset end Y side; therefore, under operating condition (3), closing the gas source device does not prevent the pressure port P from remaining closed. Therefore, under operating condition (4), the gas source device is shut off and the valve remains in its original state.

[0024] (5) Provided that the pressure port P and the working port A are connected, air is introduced from the working port A. Valve core 2-1 is on the reversing end X side, and pressure port P and working port A are connected. When gas flows in from working port A, part of the gas flows quickly to pressure port P through the second check valve 5. The gas at pressure port P flows slowly into the first gas container 1 through the first throttle valve 3 and slowly builds pressure at the reversing end X. The other part of the gas at working port A flows quickly into the second gas container 8 through the third check valve 6 and quickly builds pressure at the reset end Y. Since the pressure is built more quickly at the reset end Y, valve core 2-1 remains on the reversing end X side. Therefore, in working condition (5), when pressure port P and working port A are connected, gas enters from working port A, and pressure port P and working port A remain connected.

[0025] The application of valves as described above in pneumatic teaching experiments.

[0026] This invention can instantly seal the gas in a pipeline at the initial stage of a rupture, eliminating the force of the hose flying off and fundamentally preventing injury to the operator from impact. Simultaneously, it provides effective support for the vertical cylinder, preventing the load from falling uncontrollably. Based on fluid mechanics principles, this invention utilizes the instantaneous high pressure difference caused by increased flow to drive the valve core to close. The entire process is completed automatically within 0.5 seconds, requiring no electricity or manual operation, ensuring high reliability. This invention can be directly installed at the port of pneumatic actuators (such as cylinders) or on critical pipelines, requiring minimal modification to existing pneumatic systems, not affecting the original system's operation, and is easy to install, significantly improving the safety level of existing equipment. This valve is mainly used in compressed air systems such as pneumatic teaching experimental platforms and pneumatic industrial equipment, and is particularly suitable for situations where there is a risk of hose flying off or where a cylinder drives a vertical load.

[0027] Example 1: Application in the main circuit of pneumatic teaching experimental platform or industrial equipment If the hose accidentally breaks or detaches, the pipeline can be immediately sealed to save energy and prevent the hose from flying off and causing personal injury. Figure 4 As shown, the pressure port P of the valve is connected to the air source device, and the working port A is connected to the pneumatic working system. When the main pipeline hose or the hose of the pneumatic working system ruptures, the automatic shut-off valve immediately closes, and there is no gas output from the working port A.

[0028] like Figure 4 As shown, the pipeline includes an air source a, a pneumatic triplet B, a positioning manual directional valve C, a distributor D, a manual directional valve E, a dual pneumatic directional valve F, a cylinder G, a throttle valve H, a check valve J, and a manual directional valve K. The manual directional valve E, dual pneumatic directional valve F, cylinder G, throttle valve H, check valve J, and manual directional valve K are connected and configured to form a pneumatic working system. The air source a, pneumatic triplet B, positioning manual directional valve C, and distributor D are connected and configured to form an air source device. The air source device is connected to pressure port P, and the pneumatic working system is connected to working port A.

[0029] (1) Gas source is turned on for the first time Adjust the positional manual directional valve C to the upper position, connecting its ports 1 and 2. The compressed air from air source a → pneumatic triplet B → positional manual directional valve C → distributor D → automatic shut-off valve pressure port P → automatic shut-off valve working port A → dual pneumatic directional valve F port 1 → dual pneumatic directional valve F port 4 → check valve J → cylinder G port N, flowing into the rod chamber of cylinder G; the gas from the rodless chamber of cylinder G → cylinder G port M → dual pneumatic directional valve F port 2 → dual pneumatic directional valve F port 3, discharging the gas. The cylinder is in the retracted state. The automatic shut-off valve meets the operating condition (1): when the air source is first opened, pressure port P and working port A remain connected.

[0030] (2) The pipeline is not broken, and cylinder G extends. Press the button on the manual directional valve E, and its ports 1 and 2 are connected. The gas from the working port A is automatically closed. The gas then passes through the left control port of the dual pneumatic directional valve F. The dual pneumatic directional valve F is switched to the left position. Ports 1 and 2 of the dual pneumatic directional valve F are connected. The gas from the working port A enters the M port of cylinder G, which is the rodless chamber of cylinder G. The gas from the rod chamber of cylinder G passes through the N port, the throttle valve H, the 4 port of the dual pneumatic directional valve F, and the 5 port of the dual pneumatic directional valve F, thus venting the gas and causing the cylinder to slowly extend.

[0031] The pipeline was not ruptured, and the cylinder retracted.

[0032] Press the button on the manual directional valve K, and its ports 1 and 2 are connected. The gas at the working port A is automatically closed. The gas then passes through the right control port of the dual pneumatic directional valve F. The dual pneumatic directional valve F is switched to the right position. Ports 1 and 4 of the dual pneumatic directional valve F are connected. The gas at the working port A passes through the check valve J, through the N port of cylinder G, and into the rod chamber of cylinder G. The gas in the rodless chamber of cylinder G passes through port M, through port 2 of the dual pneumatic directional valve F, and through port 3 of the dual pneumatic directional valve F, thus venting the gas and causing the cylinder to retract quickly.

[0033] The automatic shut-off valve meets operating condition 2: the pipeline is not broken, the cylinder operates normally, and the pressure port P and the working port A remain connected.

[0034] (3) Pipeline rupture If the main pipeline hose or the hose of the pneumatic working system accidentally ruptures or detaches, and a large flow of gas flows out from working port A, the automatic shut-off valve will automatically close to prevent gas from flowing out from working port A, saving energy and preventing personal injury caused by the hose flying off. The automatic shut-off valve meets operating condition 3: When the pipeline suddenly detaches or ruptures, the automatic shut-off valve will automatically close, reliably sealing the pressure port P.

[0035] (4) Shut down the gas supply device When the pneumatic working system is not in operation for an extended period, adjust the positional manual directional valve C to the lower position, connecting its ports 2 and 3. Air from the automatic shut-off valve and the pneumatic working system will be discharged from port 3 of the positional manual directional valve C, reducing the pressure at pressure port P to 0. The automatic shut-off valve will then meet operating condition 4, shutting off the air supply device and maintaining its original state.

[0036] Example 2: Application in equipment with vertically mounted cylinders The rodless chamber of a cylinder is typically used for lifting loads, such as... Figure 5 As shown, if the branch hose connecting the rodless chamber suddenly breaks or falls off during the operation of the cylinder, the automatic shut-off valve will immediately close, sealing the gas in the rodless chamber of the cylinder, locking the cylinder, and preventing the cylinder from falling out of control.

[0037] like Figure 5As shown, the pipeline includes an air source a, a pneumatic triplet B, a positioning manual directional valve C, a distributor D, a manual directional valve E, a dual pneumatic directional valve F, a cylinder G, a throttle valve H, a check valve J, and a manual directional valve K. The manual directional valve E, dual pneumatic directional valve F, cylinder G, throttle valve H, check valve J, and manual directional valve K are connected and configured to form a pneumatic working system. The air source a, pneumatic triplet B, positioning manual directional valve C, and distributor D are connected and configured to form an air source device. The air source device is connected to the pneumatic working system. One port of the pneumatic working system is connected to the working port A, and the other port of the pneumatic working system is connected to the pressure port P.

[0038] (1) The pipeline is not ruptured, and the description of the cylinder rising process is as follows: Pressing the button on manual directional valve E connects ports 1 and 2. Compressed air from air source a → pneumatic triplet B → positional manual directional valve C → distributor D → port 1 of manual directional valve E → port 2 of manual directional valve E → left control port of dual pneumatic directional valve F → dual pneumatic directional valve F switches to the left position → ports 1 and 2 of dual pneumatic directional valve F connect → gas passes through check valve J → working port A of automatic shut-off valve → pressure port P of automatic shut-off valve → port M of cylinder G → rodless chamber of cylinder G; gas in the rod chamber of cylinder G passes through port N → port 4 of dual pneumatic directional valve F → port 5 of dual pneumatic directional valve F, discharging the gas and causing the cylinder to rise rapidly. The automatic shut-off valve meets operating condition 5: air enters from working port A, while pressure port P and working port A remain connected.

[0039] (2) Description of the cylinder descent process: The pipeline is not ruptured. Pressing the button on the manual directional valve K connects ports 1 and 2. Compressed air from air source a → pneumatic triplet B → positional manual directional valve C → distributor D → port 1 of manual directional valve K → port 2 of manual directional valve K → right control port of dual pneumatic directional valve F → dual pneumatic directional valve F is switched to the right position → ports 1 and 4 of dual pneumatic directional valve F are connected → gas flows to port N of cylinder G → into the rod chamber; gas in the rodless chamber of cylinder G passes through port M → pressure port P of the automatic shut-off valve → working port A of the automatic shut-off valve → throttle valve H → port 2 of dual pneumatic directional valve F → port 3 of dual pneumatic directional valve F, discharging the gas and causing the cylinder to descend slowly. The automatic shut-off valve meets operating condition 2: the pipeline is not ruptured, the cylinder operates normally, and pressure port P and working port A remain connected.

[0040] (3) Pipeline rupture When the cylinder descends, the branch hose ruptures, and a large amount of gas in the rodless chamber flows to the pressure port P of the automatic shut-off valve, and then to the working port A of the automatic shut-off valve. The automatic shut-off valve automatically closes, sealing the gas in the rodless chamber and preventing the cylinder G from falling uncontrollably. The automatic shut-off valve meets the requirements of operating condition 3: when the pipeline suddenly ruptures or detaches, the automatic shut-off valve automatically closes, reliably sealing the pressure port P.

[0041] Example 3: Pneumatic Teaching Practice Test Experimental test (1): The automatic shut-off valve is installed in the main gas line. When the main gas line is broken, it shuts off the gas source. Using existing valve components in the laboratory, according to Figure 1 A physical system was built, and based on Figure 4 The entire circuit experimental system was built, such as Figure 6 As shown, verify whether the automatic valve shut-off function can be implemented. Figure 6 Components and Figure 1 , Figure 4 Consistent.

[0042] Figure 6 In the design, the gas container is simulated using a flexible hose, a pressure gauge measures the pressure at the reversing end X and the reset end Y, and a flow meter measures the gas flow rate. A switching valve simulates a pipeline rupture. The gas source pressure is 4.2 bar; the cylinder piston diameter is 25 mm, and the stroke is 100 mm; the flow meter range is 0–100 L / min. It should be noted that components 3 and 4 (components 6 and 7) are integrated units of a check valve and a throttle valve in the actual design, thus one integrated unit replaces two independent components. Throttle valve 10 is simulated in the actual design using a switching valve with a reduced opening.

[0043] Turn on the gas supply device. If the pipeline is not ruptured, operate the manual directional valve E; cylinder G will slowly and steadily extend at a gas flow rate of 8 L / min, with a pressure difference of 0.1 bar between the reversing end X and the reset end Y. Operate the manual directional valve K; cylinder G will quickly retract. Cylinder G can repeatedly extend and retract; the automatic valve closing has no impact on the existing circuit.

[0044] Simulate pipeline rupture. Gradually increase the opening of the switching valve to simulate the degree of pipeline rupture. When the gas flow rate is 60 L / min, the pressure difference between the reversing end X and the reset end Y is 1 bar, and the automatic shut-off valve remains open. When the gas flow rate reaches 70 L / min, the automatic shut-off valve closes within 0.5 seconds. As can be seen from the experimental test (1), when the pipeline ruptures, the high pressure difference generated by the large flow of gas at the reversing end X and the reset end Y of the automatic shut-off valve can quickly and reliably drive the automatic shut-off valve to close, sealing the gas in the pipeline, eliminating the force of the hose flying, and avoiding the hose from causing jerk injury to the operator.

[0045] Experimental test (2): The automatic shut-off valve is installed in the branch line. When the branch line hose ruptures, the gas in the rodless chamber of the sealing cylinder is blocked. according to Figure 5 The schematic diagram was used to build the experimental system, such as Figure 7 As shown. Figure 7A one-way valve is connected in parallel across the flow meter. Its function is to allow gas to flow through this one-way valve to the working port A of the automatic shut-off valve when the cylinder rises (because gas cannot pass through the flow meter in the reverse direction). Since the automatic shut-off valve is used in a pneumatic branch line with a relatively small gas flow rate, the third throttle valve 10 is appropriately closed to generate a sufficient pressure differential.

[0046] The pipeline was not ruptured. Pressing the button on manual directional valve E caused the cylinder to rise rapidly. Pressing the button on manual directional valve K caused the cylinder to descend slowly. When the cylinder descended steadily, the flow rate was almost zero (later replaced with a small-range flow meter, the flow rate was measured to be 0.5 L / min), and the pressure difference between the reversing end X and the reset end Y was almost zero.

[0047] During the cylinder descent process, a simulated pipeline rupture was performed. When the gas flow rate reached 20 L / min, the automatic shut-off valve closed within 0.5 seconds, and the cylinder stopped descending. As can be seen from the experimental test (2), when the pipeline is intact, the automatic shut-off valve remains open and does not affect the normal operation of the cylinder; while when the pipeline ruptures, the automatic shut-off valve closes quickly, sealing the gas in the cylinder to prevent the load from falling out of control and avoid accidents.

[0048] This technology is simple to implement and effective, and can be applied to pneumatic teaching experimental platforms or pneumatic pipeline systems in factories to protect the safe operation of equipment. It has already been successfully applied to pneumatic teaching experimental platforms, where it is installed on the main pipeline. In the event of an accidental detachment of the hose, the air supply is immediately shut off to prevent the hose from flying off and to protect student safety.

[0049] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A pneumatic pipeline rupture automatic valve shut-off system, characterized in that: The valve system includes a first air container (1), a dual air-controlled directional valve (2), a first throttle valve (3), a first check valve (4), a second check valve (5), a third check valve (6), a second throttle valve (7), a second air container (8), a reset button (9), a third throttle valve (10), a working port (A), a pressure port (P), and an exhaust port (R). The dual air-controlled directional valve (2) is set in the horizontal direction, and a reset button (9) is installed on the horizontal side of the dual air-controlled directional valve (2). The reset button (9) can reset the working state of the dual air-controlled directional valve (2).

2. The system according to claim 1, characterized in that: The dual pneumatic reversing valve (2) is provided with 5 ports, which are respectively set as reversing end (X), input end (Z), output end (T), reset end (Y) and exhaust end (S). The exhaust end (S) is connected to the exhaust port (R). The reversing end (X) and the reset end (Y) are symmetrically arranged in the vertical direction. The input end (Z) and the output end (T) are both located at the upper part of the dual pneumatic reversing valve (2), and the exhaust end (S) is located at the lower part of the dual pneumatic reversing valve (2). The reversing end (X), input end (Z), output end (T), exhaust end (S) and reset end (Y) are arranged in the horizontal direction. The end face areas of the reset end (Y) and the reversing end (X) are the same. The reset terminal (Y) is connected to the second gas container (8), the third check valve (6), and the second throttle valve (7). The reset terminal (Y) is connected in parallel with the second gas container (8) and the third check valve (6). The reset terminal (Y) is connected in series with the second throttle valve (7). The third check valve (6) and the second throttle valve (7) are both connected to the working port (A). The second gas container (8) can store the gas entering the gas container. The working directions of the third check valve (6) and the second throttle valve (7) are opposite to each other. The third check valve (6) can allow gas to enter the gas container. The gas is input into the second gas container (8), and the second throttle valve (7) allows the gas in the second gas container (8) to be output. The gas in the second gas container (8) can give the double air-controlled directional valve (2) a force towards the reversing end (X). The input end (Z) is connected to the pressure port (P) and can input the gas from the pressure port (P) into the double air-controlled directional valve (2). The output end (T) is connected to the working port (A) through the third throttle valve (10). The third throttle valve (10) allows the gas to flow out from the double air-controlled directional valve (2) with a certain resistance. The reversing end (X) is connected to the first gas container (1), the first throttle valve (3), and the first check valve (4). The reversing end (X) is connected in parallel with the first gas container (1) and the first check valve (4). The reversing end (X) is connected in series with the first throttle valve (3). The first gas container (1) can store the gas that enters the gas container. The working directions of the first throttle valve (3) and the first check valve (4) are opposite to each other. The first check valve (4) can allow the gas output of the first gas container (1). The first throttle valve (3) can allow the gas input to the first gas container (1). The gas in the first gas container (1) can give the double gas-controlled reversing valve (2) a force toward the reset end (Y). The first throttle valve (3) and the first check valve (4) are both connected to the pressure port (P) of the valve.

3. The system according to claim 1, characterized in that: The dual pneumatic reversing valve (2) includes a first sealing ring (11), a second sealing ring (12-1), a third sealing ring (12-2), a valve core (2-1), and a valve body (2-2). The valve body (2-2) has a tubular structure. The valve core (2-1) is located inside the valve body (2-2). The first sealing ring (11) is located on the valve core (2-1) and is positioned between the reversing end (X) and the input end (Z) to prevent gas from the input end (Z) from leaking to the reversing end (X). Both the second sealing ring (12-1) and the third sealing ring (12-2) are provided with... On the valve body (2-2), the second sealing ring (12-1) is set between the input end (Z) and the output end (T) to prevent gas leakage at the input end (Z) when the valve core (2-1) is in the reset end (Y). The third sealing ring (12-2) is set between the output end (T) and the exhaust end (S) to prevent gas from the input end (Z) from leaking from the exhaust end (S). The reset button (9) can push the valve core (2-1) to reset the working state of the dual pneumatic reversing valve (2), so that the pressure port (P) and the working port (A) are reconnected.

4. The operating method of the pneumatic pipeline rupture automatic shut-off valve system as described in any one of claims 1 to 3, characterized in that: The following operating procedures are included: 1) When the pressure port (P) is connected to the air source device and the working port (A) is connected to the pneumatic working system, but the cylinder does not move. When the gas source device is turned on, gas enters through the pressure port (P). The gas cannot pass through the first check valve (4) and the second check valve (5), but there are two paths through which it can pass. One is through the first throttle valve (3) into the first gas container (1) and builds pressure at the reversing end (X). As time increases, the pressure at the reversing end (X) increases. Under the action of pressure, the reversing end (X) exerts a force on the end face of the reversing end (X) of the valve core (2-1) in the direction of the reset end (Y). The other is through the output end (T) of the valve body (2-2), through the third throttle valve (10) to the working port (A). Part of the gas in the working port (A) flows out of the valve system to fill the pneumatic working system, and the other part of the gas flows into the second gas container (8) through the third check valve (6) and quickly builds pressure at the reset end (Y). Under the action of pressure, the reset end (Y) exerts a force on the valve core (2-1) in the direction of the reset end (Y). The end face of the reset end (Y) of valve core (2-1) applies a force to the reversing end (X). Because the end face areas of the reset end (Y) and the reversing end (X) are the same, and the pressure at the reset end (Y) rises faster than that at the reversing end (X), at any moment when the pressure at the reversing end (X) and the reset end (Y) rises, the force of valve core (2-1) towards the reversing end (X) is greater than the force towards the reset end (Y). Therefore, valve core (2-1) remains in a position close to the reversing end (X). Towards the reversing end (X); when the pressurization process of the reversing end (X) and the reset end (Y) ends, the gas stops flowing, the pressure at all points inside the valve is the same and equal to the gas source pressure, the force of the valve core (2-1) toward the reversing end (X) is equal to the force toward the reset end (Y), and the valve core (2-1) remains on the side closer to the reversing end (X); therefore, under condition 1), when the gas source is first opened, the pressure port (P) and the working port (A) always remain connected; 2) Based on condition 1), the pipeline is not ruptured, and the cylinder begins to operate. At the instant the cylinder begins to move, the pressure at the working port (A) drops sharply. However, the gas at the reset end (Y) cannot flow from the third check valve (6) to the working port (A), but can only flow to the working port (A) through the second throttle valve (7). Therefore, the pressure at the reset end (Y) drops. At the same time, due to the sharp drop in pressure at the working port (A), the gas at the pressure port (P) flows to the working port (A) through the third throttle valve (10), and the pressure at the pressure port (P) will drop. At this time, the gas at the reversing end (X) quickly flows through the first check valve (4). As the flow occurs, the pressure at the reversing end (X) instantly drops to the pressure at the pressure port (P). Because the reversing end (X) and the reset end (Y) of the valve core (2-1) have the same area, and the pressure drop rate at the reset end (Y) is lower than that at the reversing end (X), the force of the valve core (2-1) toward the reversing end (X) is always greater than the force toward the reset end (Y). The valve core (2-1) remains on the side closer to the reversing end (X). Therefore, at the instant the cylinder begins to move, the pressure port (P) and the working port (A) remain connected. After a certain period of time, the cylinder operates stably, and a small flow of gas passes through the third throttle valve (10). At this time, a stable small pressure difference is generated across the three ends of the third throttle valve (10). The reversing end (X) is connected to the pressure port (P) through the first throttle valve (3), so the pressure at the reversing end (X) and the pressure port (P) remain the same. The reset end (Y) is connected to the working port (A) through the second throttle valve (7), so the pressure at the reset end (Y) and the working port (A) remain the same. Therefore, the pressure at the reversing end (X) is... The pressure difference between the valve core (2-1) and the reset end (Y) is also the pressure difference between the two ends of the third throttle valve (10). Therefore, the resultant force of the gas acting on the valve core (2-1) is towards the reset end (Y). However, because the pressure difference is small, the resultant force towards the reset end (Y) is small, and this resultant force cannot overcome the friction generated by the first sealing ring (11) and the third sealing ring (12-2). The valve core (2-1) remains at the leftmost end. Therefore, the pipeline is not broken. When the cylinder runs stably, the pressure port (P) and the working port (A) remain connected. 3) Based on condition 2), the pipeline suddenly ruptures or detaches. If the pipeline or pneumatic working system pipeline at the working port (A) suddenly ruptures or falls off, a large amount of gas will be discharged from the working port (A). At this time, a large pressure difference will be generated at both ends of the third throttle valve (10), namely the pressure difference between the reversing end (X) and the reset end (Y). This pressure difference multiplied by the end face area of ​​the valve core (2-1) is the resultant force of the gas. The direction of this resultant force is towards the reset end (Y), and the resultant force value is greater than the frictional force generated by the first sealing ring (11) and the third sealing ring (12-2). This will quickly push the valve core (2-1) to the reset end (Y) side, relying on the valve core (2-1) to close the pressure port (P) and block the flow. Gas is prevented from flowing out of the working port (A); after the pressure port (P) is closed, the pressure at the reversing end (X) is kept the same as the pressure at the pressure port (P) through the first throttle valve (3), which is the gas source pressure. The working port (A) is connected to the exhaust port (R), and the pressure at the working port (A) drops to 0. The reset end (Y) is connected to the working port (A) through the second throttle valve (7), and the pressure at the reset end (Y) also drops to 0. The resultant force of the gas is still towards the reset end (Y) side, so the valve core (2-1) is maintained on the reset end (Y) side. Therefore, when the pipeline suddenly falls off or breaks, the valve automatically closes, sealing the pressure port (P). 4) In operating conditions 1), 2), and 3), shut off the gas supply device. Under operating conditions 1) and 2), the valve core (2-1) is on the reversing end (X) side, and the pressure port (P) and working port (A) are connected. Closing the air source device causes the gas at the pressure port (P) to be discharged rapidly, and the pressure at the pressure port (P) drops to 0. At this time, the gas at the reversing end (X) is discharged rapidly through the first check valve (4), and the pressure at the reversing end (X) immediately drops to 0. At the same time, since the pressure at the pressure port (P) drops to 0, the gas at the reset end (Y) flows out through the second throttle valve (7), and the pressure at the reset end (Y) drops. Since the rate of pressure drop at the reset end (Y) is lower than the rate of pressure drop at the reversing end (X), the force of the valve core (2-1) towards the reversing end (X) is greater than the force towards the reset end (Y), and the valve core (2-1) remains on the reversing end (X) side. Therefore, under operating conditions 1) and 2), when the air source device is closed, the pressure port (P) and working port (A) are still connected. Under operating condition 3), the valve core (2-1) is on the reset end (Y) side, the pressure port (P) is closed, the pressure at the reversing end (X) is the air source pressure, and the pressure at the reset end (Y) is 0. Closing the air source device causes the gas at the pressure port (P) to be discharged rapidly, and the pressure at the pressure port (P) drops to 0. At this time, the gas at the reversing end (X) is discharged rapidly through the first check valve (4), and the pressure at the reversing end (X) immediately drops to 0. Since the pressure at the reset end (Y) is also 0, the valve core (2-1) remains on the reset end (Y) side. Therefore, under operating condition 3), even when the air source device is closed, the pressure port (P) remains closed. Therefore, under operating condition 4), the gas supply device is shut off, and the valve remains in its original state; 5) With the pressure port (P) and the working port (A) connected, air is introduced through the working port (A). The valve core (2-1) is on the reversing end (X) side, and the pressure port (P) and the working port (A) are connected. When the gas flows in from the working port (A), part of the gas flows to the pressure port (P) through the second check valve (5). The gas from the pressure port (P) flows into the first gas container (1) through the first throttle valve (3) and establishes pressure at the reversing end (X). The other part of the gas from the working port (A) flows into the second gas container (8) through the third check valve (6) and quickly establishes pressure at the reset end (Y). Since the pressure is established at the reset end (Y) faster than at the reversing end (X) side, the valve core (2-1) remains on the reversing end (X) side. Therefore, in the case of working condition (5) where the pressure port (P) and the working port (A) are connected, the gas enters from the working port (A), and the pressure port (P) and the working port (A) remain connected.

5. The application of the system as described in any one of claims 1 to 3 in pneumatic teaching experiments.

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