Automatic shut-off valve for pipeline breakage and hydraulic system

Abstract

The present application belongs to the technical field of hydraulic components, and discloses a pipeline breakage automatic shut-off valve and a hydraulic system, which comprises a main control valve and a mode switching system. The main control valve comprises a main valve block, a differential pressure sensing valve, a Pitot tube and a stop valve, and the main valve block is provided with an inlet and an outlet. The mode switching system comprises an electromagnetic reversing valve and a mode switching valve, and the mode switching valve and the electromagnetic reversing valve are connected to the main valve block through a transition valve block. The Pitot tube is arranged in the main valve block and extends into the inlet at one end and is in communication with a high-pressure cavity of the differential pressure sensing valve at the other end. The mode switching system switches the working state of the shut-off valve in two control modes of manual control and hydraulic remote control through the mode switching valve and the electromagnetic reversing valve. The main control valve senses the flow change through the Pitot tube and the differential pressure sensing valve, and then controls the opening and closing of the stop valve, so as to realize the opening and closing of the shut-off valve.

Description

An automatic shut-off valve and hydraulic system for pipeline rupture Technical Field

[0001] This invention belongs to the technical field of hydraulic components, and more specifically, relates to an automatic shut-off valve for pipeline damage and a hydraulic system. Background Technology

[0002] In existing hydraulic systems, pipelines serve as crucial channels for transmitting hydraulic oil, and their integrity is essential for the normal operation of the system. However, due to the complex and variable working environment of hydraulic systems, pipelines may be damaged by external impacts, long-term vibrations, corrosion, aging, and other factors. Once a pipeline is damaged, it can lead to a large leakage of hydraulic oil, causing not only energy waste and environmental pollution, but also a rapid drop in system pressure, affecting the normal operation of equipment, and potentially even triggering safety accidents.

[0003] However, current designs typically use flow coefficients for flow-pressure conversion in flow calculations. But flow coefficients are affected by various conditions, and even with a fixed structure, their values ​​are difficult to determine precisely, making it difficult for the device to operate accurately. Moreover, conventional designs often employ a purely automatic shutdown mode, meaning that the flow channels cannot be forcibly opened or closed manually after system installation, leading to inconvenience in emergency situations or during equipment maintenance. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides an automatic shut-off valve and hydraulic system for pipeline damage, which aims to solve the problem of the single shut-off mode of the existing shut-off elements.

[0005] To achieve the above objectives, according to one aspect of the present invention, an automatic shut-off valve for pipeline rupture is provided. The shut-off valve includes a mode switching system and a main control valve. The main control valve includes a main valve block, a differential pressure sensing valve disposed on the main valve block, a Pitot tube, and a shut-off valve. The main valve block has an inlet and an outlet. The mode switching system includes a solenoid directional valve and a mode switching valve. The mode switching valve and the solenoid directional valve are connected to the main valve block via a transition valve block. The solenoid directional valve is a three-position four-way solenoid directional valve, and its four ports are respectively connected through channels inside the transition valve block to the right end and left end of the mode switching valve, the high-pressure chamber of the differential pressure sensing valve, and the drain port on the main valve block. The Pitot tube is disposed within the main valve block, with one end extending into the inlet and the other end connected to the... The high-pressure chamber is connected; the right end of the differential pressure sensing valve is connected to the high-pressure chamber, and the left end is connected to the outlet. Its first sensing valve port and second sensing valve port are respectively connected to the drain port and the second switching valve port of the mode switching valve; one end of the shut-off valve is connected to the outlet, and the other end is connected to the third switching valve port of the mode switching valve; the first switching valve port and the fourth switching valve port of the mode switching valve are respectively connected to the drain port and the high-pressure chamber; the mode switching system switches the working state of the shut-off valve through the mode switching valve and the solenoid directional valve in two control modes: manual control and hydraulic remote control; the main control valve senses the flow change through the Pitot tube and the differential pressure sensing valve, and then controls the opening and closing of the shut-off valve to realize the opening and closing of the shut-off valve.

[0006] Furthermore, the main valve block is also provided with a first stepped groove, which connects the inlet and the outlet; the first stepped groove is used to accommodate the shut-off valve; the main valve block is also provided with a second stepped groove, which connects to the outlet; the second stepped groove is used to accommodate the differential pressure sensing valve.

[0007] Furthermore, the main valve block is also provided with a receiving groove for receiving a signal sensor, which is used to detect the on / off state of the main control valve.

[0008] Furthermore, the shut-off valve includes a shut-off spring, a shut-off valve cover, a shut-off valve core, a shut-off spring cone, and a shut-off valve core push rod. The shut-off valve cover is stepped, with one end disposed in the first stepped groove. One end of the shut-off valve core is disposed in the shut-off valve cover, and the other end is connected to the shut-off valve core push rod. The other end of the shut-off valve core push rod is disposed opposite to the push rod of the signal sensor. The shut-off spring cone is disposed in the shut-off valve core, with one end of the shut-off spring connected to the shut-off spring cone and the other end connected to the shut-off valve cover.

[0009] Furthermore, the bottom of the shut-off valve cover is hexagonal prism-shaped, and its upper end has a first annular boss formed around its own central axis. The first annular boss forms two axial stepped cavities, namely the first stepped cavity and the second stepped cavity from top to bottom. A first expansion cavity is formed between the first stepped cavity and the second stepped cavity. Two centrally symmetrical oblique channels are provided on the cavity wall of the first expansion cavity. A shut-off valve core back pressure cavity is formed between the shut-off valve cover and the shut-off valve core. The first expansion cavity and the second stepped cavity are components of the shut-off valve core back pressure cavity.

[0010] Furthermore, a damping orifice is provided in the pipeline between the back pressure chamber of the shut-off valve core and the third switching valve port.

[0011] Further, the differential pressure sensing valve includes a sensing valve cover, a sensing valve core, an adjusting screw, a sensing valve piston, a sensing spring seat, a sensing spring, a sensing spring cone, an automatic valve sleeve, and an automatic valve core; one end of the sensing valve cover is disposed in the second stepped groove, one end of the sensing valve core is disposed in the sensing valve cover, and the other end is connected to the automatic valve core; the automatic valve core is disposed in the automatic valve sleeve, and the automatic valve sleeve is disposed in the second stepped groove; the sensing valve piston is disposed in the sensing valve cover, one end of which abuts against the adjusting screw, and the other end is connected to one of the sensing spring seats, and the sensing spring cone is disposed in the sensing valve core; both ends of the sensing spring are respectively connected to the sensing spring seat and the sensing spring cone; the high-pressure chamber is formed between the end of the sensing valve cover housed in the second stepped groove and the second stepped groove.

[0012] Furthermore, the mode switching valve includes a switching valve body, a switching valve sleeve, a switching valve core, a positioning sleeve, a centering spring, a centering spring seat, and an elastic retaining ring. The switching valve sleeve and the positioning sleeve are coaxially disposed within the switching valve body and abut against each other. Two centering spring seats are spaced apart within the positioning sleeve, and the two ends of the centering spring are respectively connected to the two centering spring seats. The elastic retaining ring is disposed adjacent to the centering spring seats and is located outside the positioning sleeve and inside the switching valve body. The switching valve core is located within the switching valve body, with one end passing sequentially through the switching valve sleeve, one centering spring seat, the centering spring, the other centering spring seat, and the elastic retaining ring, and the other end connected to the manual control lever.

[0013] Furthermore, the manual control lever includes a handle, a set screw, a handle spring, a handle limiting plate, a shift fork spindle, a shift fork, and a shift head. The handle limiting plate is connected to one side of the switching valve body and has a through circular hole for the shift fork spindle to pass through. One end of the shift fork spindle passes through the handle and extends into the switching valve body, connecting to one end of the shift fork. The other end of the shift fork is connected to the shift head, which is connected to the end of the switching valve core away from the centering spring seat. The handle spring and the set screw are both located in the handle near the circular hole. The two ends of the handle spring are respectively connected to the bottom of the inner groove of the handle and the set screw is housed in the inner groove.

[0014] The present invention also provides a hydraulic system, the hydraulic system including hydraulic pipelines and an automatic shut-off valve for pipeline failure as described above, the automatic shut-off valve for pipeline failure being connected in series on the hydraulic pipelines.

[0015] In summary, compared with the prior art, the automatic shut-off valve and hydraulic system for pipeline rupture provided by the present invention have the following advantages:

[0016] 1. The mode switching system switches the operating state of the shut-off valve through the mode switching valve and the solenoid directional valve in two control modes: manual control and hydraulic remote control. The main control valve senses flow changes through the Pitot tube and the differential pressure sensing valve, and then controls the opening and closing of the shut-off valve to realize the opening and closing of the shut-off valve. This invention has two control modes: manual control and hydraulic remote control, as well as three operating states: "normally open", "normally closed", and "automatic". It achieves multi-scenario adaptability and can switch modes whether operated on-site or remotely. Under various working conditions, it can ensure the safe and stable operation of the pipeline system and greatly improve reliability.

[0017] 2. This invention uses a damping orifice to improve its shut-off characteristics. By adjusting the damping orifice, different shut-off dynamic performances of the shut-off valve core and the sensing valve core can be obtained, which can optimize the shut-off speed of the shut-off valve core and enhance stability. It has high working stability and a large adjustment range of shut-off flow rate.

[0018] 3. This automatic shut-off valve first draws flow through a Pitot tube, and then the sensing valve core detects the flow change, causing the shut-off valve core to move. In the process of converting flow rate to differential pressure, the Pitot tube does not rely on a flow coefficient to determine the relationship between the two. This allows the automatic shut-off valve to operate precisely according to the set shut-off flow rate under different operating conditions, effectively improving the accuracy and reliability of flow control.

[0019] 4. This invention achieves different shut-off flow settings by adjusting the preload of the sensing spring, which can adapt to the flow protection requirements of different hydraulic systems, avoids customized design for a single working condition, and has strong adaptability to working conditions.

[0020] 5. This invention is divided into independent modules such as the main control valve, the transition valve block, and the mode switching system. They are connected through standardized interfaces. The modular design supports quick disassembly and replacement of parts, shortening maintenance time. It can also be adapted to different pipe diameters by replacing modules.

[0021] 6. This invention integrates the shut-off valve and the differential pressure sensing valve into a single valve body of the main control valve, uses a transition valve block to connect the mode switching valve and the solenoid directional valve, and achieves functional linkage through built-in flow channels, reducing external pipeline connections, resulting in a compact structure, small space occupation, and low leakage risk. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the principle of an automatic shut-off valve for pipeline damage provided by the present invention;

[0023] Figure 2 is a schematic diagram of the main control valve of the automatic shut-off valve for pipeline damage shown in Figure 1.

[0024] Figure 3 is a schematic diagram of the mode switching system of the automatic shut-off valve for pipeline damage in Figure 1;

[0025] Figure 4 is a schematic diagram of the mode switching valve of the automatic shut-off valve for pipeline damage in Figure 1;

[0026] Figure 5(a) and (b) are the working status diagrams of the automatic shut-off valve for pipeline damage in Figure 1, respectively.

[0027] Figure 6 is a schematic diagram of the manual control lever of the automatic shut-off valve for pipeline damage shown in Figure 1.

[0028] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 101-signal sensor, 110-main valve block, 111-pitoton, 112-inlet, 113-outlet, 114-drain port, 115-inlet connector, 116-outlet connector, 117-high pressure chamber, 118-stop valve core back pressure chamber, 120-stop valve, 121-stop spring, 122-stop valve cover, 123-stop valve core, 124-stop spring cone, 125-stop valve core push rod, 130-differential pressure sensing valve, 131-sensing valve cover, 132-sensing valve core, 133-adjusting screw, 134-sensing valve piston, 135-sensing spring seat, 136-sensing spring, 137-sensing spring cone, 138-sensing valve core bore 139-Sensing valve cover channel, 141-Automatic valve core, 142-Automatic valve sleeve, 143-First sensing valve port, 144-Second sensing valve port, 210-Transition valve block, 220-Manual operating lever, 221-Handle, 222-Setting screw, 223-Handle spring, 224-Handle limit plate, 225-Shift fork spindle, 226-Shift fork, 227-Shift head, 230-Solenoid directional valve, 240-Mode switching valve, 241-Switching valve body, 242-Switching valve sleeve, 243-Switching valve core, 244-Positioning sleeve, 245-Centering spring, 246-Centering spring seat, 247-Switching valve core channel, 251-First switching valve port, 252-Second switching valve port, 253-Third switching valve port, 254-Fourth switching valve port. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Please refer to Figures 1 and 3. The present invention provides an automatic shut-off valve for pipeline rupture. The shut-off valve includes a mode switching system and a main control valve. The main control valve includes a main valve block 110, a differential pressure sensing valve 130, a Pitot tube 111, and a shut-off valve 120 disposed on the main valve block 110. The main valve block 110 has an inlet 112 and an outlet 113. The mode switching system includes a solenoid directional valve 230 and a mode switching valve 240. The mode switching valve 240 and the solenoid directional valve 230 are connected to the main valve block 110 through a transition valve block 210. The electromagnetic directional valve 230 is a three-position four-way electromagnetic directional valve. Its four valve ports are respectively connected to the right end and left end of the mode switching valve 240, the high-pressure chamber 117 of the differential pressure sensing valve 130, and the oil drain port 114 opened in the main valve block 110 through the internal channels of the transition valve block 210. The Pitot tube 111 is disposed in the main valve block 110, with one end extending into the inlet 112 and the other end connected to the high-pressure chamber 117. The right end of the differential pressure sensing valve 130 is connected to the high-pressure chamber 117, and the left end is connected to the outlet 113. Its first sensing valve port 143 and second sensing valve port 144 are respectively connected to the oil drain port 114 and the second switching valve port 252 of the mode switching valve 240. One end of the shut-off valve 120 is connected to the outlet 113, and the other end is connected to the third switching valve port 253 of the mode switching valve 240. The first switching port 251 and the fourth switching port 254 of the mode switching valve 240 are respectively connected to the oil drain port 114 and the high pressure chamber 117.

[0031] The mode switching valve 240 is a three-position four-way valve, and the differential pressure sensing valve 130 is a two-position three-way valve. The mode switching system uses the mode switching valve 240 and the solenoid directional valve 230 to switch the operating state of the shut-off valve in two control modes: manual control and hydraulic remote control. The operating states include normally open, normally closed, and automatic. The main control valve senses changes in flow rate through the Pitot tube 111 and the differential pressure sensing valve 130, and then controls the opening and closing of the shut-off valve 120 to realize the opening and closing of the shut-off valve.

[0032] When in use, the shut-off valve is connected in series in the pressure pipeline of the hydraulic system. When the flow rate of the medium in the pipeline increases abnormally and exceeds the set value, it can automatically disconnect the pressure pipeline to protect the hydraulic power source. The shut-off valve has automatic sensing and switching, on-site manual control and remote hydraulic remote control functions, and features fast response speed and small pressure shock. It can effectively improve the safety and maintainability of the hydraulic system, and is suitable for various hydraulic systems to ensure their stable operation.

[0033] Please refer to Figure 2. The inlet 112 and the outlet 113 are located on opposite sides of the main valve block 110. An inlet connector 115 is provided at the inlet 112 for connecting to the upstream oil supply pipeline. An outlet connector 116 is provided at the outlet 113 for connecting to the downstream oil outlet pipeline.

[0034] The main valve block 110 also has a first stepped groove, which connects the inlet 112 and the outlet 113. The first stepped groove is used to accommodate the shut-off valve 120. In this embodiment, the central axis of the inlet 112 is parallel to the central axis of the outlet 113, and the central axis of the first stepped groove is parallel to the central axis of the drain port 114, and both are perpendicular to the central axis of the inlet 112. The main valve block 110 also has a second stepped groove, which is connected to the outlet 113. In this embodiment, the central axis of the second stepped groove is parallel to the central axis of the inlet 112; one end of the Pitot tube 111 is located in the inlet connector 115, and the other end is connected to the high-pressure chamber 117 through a pipe in the main valve block 110. The second stepped groove is used to accommodate the differential pressure sensing valve 130.

[0035] The main valve block 110 is also provided with a receiving groove for receiving a signal sensor 101, which is used to detect the on / off state of the main control valve. The receiving groove is connected to the first stepped groove, and their central axes coincide.

[0036] The shut-off valve includes a shut-off spring 121, a shut-off valve cover 122, a shut-off valve core 123, a shut-off spring cone 124, and a shut-off valve core push rod 125. The shut-off valve cover 122 is stepped, with one end disposed in the first stepped groove. One end of the shut-off valve core 123 is disposed inside the shut-off valve cover 122, and the other end is connected to the shut-off valve core push rod 125. The other end of the shut-off valve core push rod 125 is opposite to the push rod of the signal sensor 101, and the two are coaxial. The shut-off spring cone 124 is disposed inside the shut-off valve core, and one end of the shut-off spring 121 is connected to the shut-off spring cone 124, and the other end is connected to the shut-off valve cover 122.

[0037] The bottom of the shut-off valve cover 122 is hexagonal prism-shaped, and its upper end has a first annular boss formed around its central axis. The first annular boss forms two axial stepped cavities, namely a first stepped cavity and a second stepped cavity from top to bottom. The diameter of the first stepped cavity is larger than that of the second stepped cavity. A first enlarged-diameter cavity is formed between the first stepped cavity and the second stepped cavity, and two centrally symmetrical oblique channels are provided on the cavity wall of the first enlarged-diameter cavity. A shut-off valve core back pressure cavity 118 is formed between the shut-off valve cover 122 and the shut-off valve core 123, and the first enlarged-diameter cavity and the second stepped cavity are components of the shut-off valve core back pressure cavity 118.

[0038] The shut-off valve core 123 is a cylindrical rotating body with a closed top. A first boss is formed at the center of the top, and the first boss has a threaded hole. The shut-off valve core 123 is connected to the shut-off valve core push rod 125 through the threaded hole. A first conical groove is formed on the bottom surface of the inner cavity of the shut-off valve core 123. The first conical groove cooperates with the shut-off spring cone head 124. One end of the shut-off spring 121 is installed in the second stepped cavity of the shut-off valve cover 122 to hold one end of the shut-off spring 121 in place, and the other end of the shut-off spring 121 is sleeved on the shut-off spring cone head 124.

[0039] In this embodiment, a damping hole is provided on the pipeline between the back pressure chamber 118 of the shut-off valve core and the third switching valve port 253, and is located at the junction of the main valve block 110 and the transition valve block 210.

[0040] The differential pressure sensing valve 130 includes a sensing valve cover 131, a sensing valve core 132, an adjusting screw 133, a sensing valve piston 134, a sensing spring seat 135, a sensing spring 136, a sensing spring cone 137, an automatic valve sleeve 142, and an automatic valve core 141. One end of the sensing valve cover 131 is disposed in the second stepped groove. One end of the sensing valve core 132 is disposed in the sensing valve cover 131, and the other end is connected to the automatic valve core 141. The automatic valve core 141 is disposed in the automatic valve sleeve 142, which is disposed in the second stepped groove. The sensing valve piston 134 is disposed in the sensing valve cover 131, with one end abutting against the adjusting screw 133 and the other end connected to one of the sensing spring seats 135. The sensing spring cone 137 is disposed in the sensing valve core 132. The two ends of the sensing spring 136 are respectively connected to the sensing spring seat 135 and the sensing spring cone 137. The high-pressure chamber 117 is formed between the end of the sensing valve cover 131 housed in the second stepped groove and the second stepped groove.

[0041] The sensing valve core 132 is a cylindrical rotating body with a closed top. A first annular groove is formed on its surface. Four centrally symmetrical and evenly distributed sensing valve core channels 138 are opened on the first annular groove. The sensing valve core channels 138 are connected to the sensing valve core 132.

[0042] The sensing valve cover 131 is a cylindrical body with an axial through hole. The axial through hole is a four-step hole, consisting of a first-step hole, a second-step hole, a third-step hole, and a fourth-step hole that are coaxially connected from left to right. The diameter of each hole decreases in the order of fourth-step hole, third-step hole, first-step hole, and second-step hole. The first-step hole is used to accommodate the adjusting screw 133, the second-step hole is used to accommodate the sensing valve piston 134, and the fourth-step hole is used to accommodate the sensing valve core 132.

[0043] During assembly, the adjusting screw 133 presses against the bottom end of the sensing valve piston 134, and the top of the sensing valve piston 134 engages with the sensing spring 136. The conical protrusion at the top of the sensing spring cone 137 rests within the second conical groove of the sensing valve core 132. A sensing valve cover channel 139 is provided on the outer wall of the sensing valve cover 131 where it mates with the main valve block 110. The sensing valve core 132 connects to the outlet 113 through the sensing valve core channel 138, the sensing valve cover channel 139, and the internal flow channel of the main valve block 110. The high-pressure chamber 117 connects to the Pitot tube 111 through the internal flow channel of the main valve block 110.

[0044] A second protrusion is formed at the center of the top outer side of the sensing valve core 132. The second protrusion has a second-order U-shaped groove along the axial direction, with the outer groove diameter being smaller than the inner one. The second-order U-shaped groove forms a snap-fit ​​connection structure with the automatic valve core 141. The automatic valve sleeve 142 is a cylindrical body with an axial through hole. Its inner diameter matches the outer diameter of the automatic valve core 141. It has two sets of channels, each set consisting of four centrally symmetrical and evenly distributed channels, which are, from left to right, the first sensing valve port 143 and the second sensing valve port 144.

[0045] When the flow rate of the medium in the pipeline does not exceed the set value, the sensing valve core 132 is maintained in its initial position by the spring force of the sensing spring 136, the back pressure chamber 118 of the shut-off valve core is connected to the drain port 114, and the shut-off valve core 123 remains open; when the flow rate of the medium in the pipeline exceeds the set value, the total pressure pushes the sensing valve core 132 to the left to switch the oil circuit, so that the back pressure chamber 118 of the shut-off valve core is connected to the high pressure chamber 117, and forms a cooperative locking force with the shut-off spring 121, forcing the shut-off valve core 132 to quickly cut off the flow channel, and the shut-off valve core push rod 125 contacts the push rod of the signal sensor 101, indicating the disconnected state.

[0046] Please refer to Figures 4 and 5. The mode switching valve 240 includes a switching valve body 241, a switching valve sleeve 242, a switching valve core 243, a positioning sleeve 244, a centering spring 245, a centering spring seat 246, and an elastic retaining ring. The switching valve sleeve 242 and the positioning sleeve 244 are coaxially arranged within the switching valve body 241 and abut against each other. Two centering spring seats 246 are spaced apart within the positioning sleeve 244, and the two ends of the centering spring 245 are respectively connected to the two centering spring seats 246. The elastic retaining ring is arranged adjacent to the centering spring seats 246 and is located outside the positioning sleeve 244 and inside the switching valve body 242. The switching valve core 243 is located inside the switching valve body 241, with one end passing sequentially through the switching valve sleeve 242, one centering spring seat 246, the centering spring 245, the other centering spring seat 246, and the elastic retaining ring, and the other end connected to the manual operating lever 220.

[0047] The switching valve body 241 has a through third stepped groove, and the switching valve sleeve 242, the positioning sleeve 244, and the elastic retaining ring are disposed within the third stepped groove. The switching valve sleeve 242 has four sets of flow channel holes that communicate with its internal flow channels, which are, from left to right, the first switching valve port 251, the second switching valve port 252, the third switching valve port 253, and the fourth switching valve port 254. The oblique channel connects the back pressure chamber 118 of the shut-off valve core to the third switching valve port 253 through the internal flow channels of the main valve block 110 and the transition valve block 210; the first sensing valve port 143 connects to the drain port 114 and the first switching valve port 251 through the internal flow channels of the main valve block 110 and the transition valve block 210; the second sensing valve port 144 connects to the second switching valve port 252 through the internal flow channels of the main valve block 110 and the transition valve block 210; the right side of the automatic valve core 141 connects to the high pressure chamber 117 and the fourth switching valve port 254 through the internal flow channels of the main valve block 110 and the transition valve block 210.

[0048] The switching valve core 243 has three annular grooves. Each of the two left-side reversing grooves has four centrally symmetrical and evenly distributed switching valve core channels 247. These channels 247 connect to the corresponding two annular grooves via internal flow channels within the switching valve core 243. During assembly, the flange of the centering spring seat 246 presses against the centering spring 246. The inner diameter of the centering spring seat 246 matches the outer diameter of the stepped shaft on the right side of the switching valve core 243. The centering spring 246 and the centering spring seat 246 are then positioned within the positioning sleeve 244.

[0049] Referring to Figure 6, the manual control lever 220 includes a handle 221, a set screw 222, a handle spring 223, a handle limiting plate 224, a shift fork spindle 225, a shift fork 226, and a shift head 227. The handle limiting plate 224 is connected to one side of the switching valve body 241 and has a through circular hole for the shift fork spindle 225 to pass through. One end of the shift fork spindle 225 passes through the handle 221 and extends into the switching valve body 241, connecting with one end of the shift fork 226. The other end of the shift fork 226 is connected to the shift head 227, which is connected to the end of the switching valve core 243 away from the centering spring seat 246. The side of the shift head 227 has radial through surfaces spaced 180° apart to mate with the fork-shaped groove of the shift fork 226. The square portion of the shift fork spindle 225 is inserted into the square hole of the shift fork 226. The handle spring 223 and the set screw 222 are both disposed within one end of the handle 221 adjacent to the circular hole. The two ends of the handle spring 223 are respectively connected to the bottom of the inner groove of the handle 221 and the set screw 222 is housed within one end of the inner groove. During operation, moving the handle 221 rotates the shift fork spindle 225, which in turn drives the shift fork 226 and the shift head 227 to move sequentially, ultimately moving the switching valve core 243 between three working positions. The manual control lever 220 is locked by adjusting the handle spring 223 using the set screw 222.

[0050] In the "automatic" operating state, the main control valve collects the total pressure (static pressure + dynamic pressure) of the inlet fluid through the Pitot tube 111 and applies it to the sensing valve core 132, comparing it with the outlet static pressure and the preset spring force. According to the designed automatic shut-off valve principle for pipeline damage, the flow velocity of the medium in the pipeline is positively correlated with the pressure difference, that is, the greater the flow velocity, the greater the pressure difference. When the pipeline is working normally, the shut-off valve 120 is in the initial open state. The medium flows from the inlet 112 through the shut-off valve 120 to the outlet 113. The sensing valve core 132 is in the initial position on the right. At this time, the back pressure chamber 118 of the shut-off valve core is connected to the drain port 114. Therefore, as long as the flow rate does not reach the set value of the sensing spring 136, neither the sensing valve core 132 nor the shut-off valve core 123 will move. When the flow rate reaches the set value of the sensing spring 136, the sensing valve core 132 moves to the left under the pressure of the high pressure chamber 117 on the right, which drives the automatic valve core 141 to move to the left, so that the comparison chamber is connected to the high pressure chamber 117, and thus the back pressure chamber 118 of the shut-off valve core is connected to the high pressure chamber 117, causing the shut-off valve core 123 to move and cut off the pipeline.

[0051] The mode switching valve 240 of the mode switching system has three working positions: "left", "middle" and "right". When the switching valve core 243 is in the right position, the mode switching valve 240 forcibly connects the back pressure chamber 118 of the shut-off valve core to the oil drain port 114. The shut-off valve core 123 is forcibly opened under hydraulic pressure, and the automatic shut-off valve for pipeline damage is in the "normally open" working state. When the switching valve core 243 is in the left position, the mode switching valve 240 forcibly connects the back pressure chamber 118 of the shut-off valve core to the high pressure chamber 117. The shut-off valve core 123 is forcibly closed under hydraulic pressure, and the shut-off valve core 123 cuts off the flow path of the main control valve. The automatic shut-off valve for pipeline damage is in the "normally closed" working state.

[0052] The mode switching system allows for manual control of the mode switching valve 240 when the electromagnetic directional valve 230 is de-energized. When the electromagnetic directional valve 230 is de-energized, there is no hydraulic pressure at either end, allowing for manual control. The switching valve core 243 can be moved between three operating positions via the manual lever 220. When the manual lever 220 is locked in the neutral position, remote hydraulic control is possible. This remote control uses an electrical signal to operate the electromagnetic directional valve 230, which directs oil from the high-pressure chamber 117 and drain port 114 of the main control valve to both ends of the mode switching valve 240 to control the pressure and thus the operating position of the mode switching valve 240. When manual control or hydraulic remote control is not in operation, the switching valve core 243 resets under spring force, and the automatic shut-off valve for pipeline damage is in an "automatic" operating state. The state and switching of the shut-off valve core 123 are determined by the flow rate in the main control valve's flow channel.

[0053] The compression of the sensing spring 136 of the aforementioned automatic shut-off valve for pipeline damage can be changed by adjusting the screw 133 in automatic operation, thereby fine-tuning the flow rate of the shut-off valve core 123.

[0054] The present invention also provides a hydraulic system, which includes hydraulic pipelines and an automatic shut-off valve for pipeline rupture as described above, wherein the automatic shut-off valve for pipeline rupture is connected in series on the hydraulic pipelines.

[0055] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automatic shut-off valve for pipeline rupture, characterized in that: The shut-off valve includes a mode switching system and a main control valve. The main control valve includes a main valve block, a differential pressure sensing valve mounted on the main valve block, a Pitot tube, and a shut-off valve. The main valve block has an inlet and an outlet. The mode switching system includes a solenoid directional valve and a mode switching valve. The mode switching valve and the solenoid directional valve are connected to the main valve block via a transition valve block. The solenoid directional valve is a three-position four-way solenoid directional valve, and its four valve ports are respectively connected to the right end and left end of the mode switching valve, the high-pressure chamber of the differential pressure sensing valve, and the drain port on the main valve block through channels inside the transition valve block. The Pitot tube is mounted on... The main valve block has one end extending into the inlet and the other end connected to the high-pressure chamber; the right end of the differential pressure sensing valve is connected to the high-pressure chamber of the mode switching valve, and the left end is connected to the outlet; its first sensing valve port and second sensing valve port are respectively connected to the drain port and the second switching valve port of the mode switching valve; one end of the shut-off valve is connected to the outlet, and the other end is connected to the third switching valve port of the mode switching valve; the first switching valve port and the fourth switching valve port of the mode switching valve are respectively connected to the drain port and the high-pressure chamber; the mode switching system is manually controlled via the mode switching valve and the solenoid directional valve. The shut-off valve can be switched between two control modes: automatic control and hydraulic remote control. The main control valve senses flow changes through the Pitot tube and the differential pressure sensing valve, thereby controlling the opening and closing of the shut-off valve. The main valve block also has a first stepped groove connecting the inlet and outlet, used to house the shut-off valve. The main valve block also has a second stepped groove connected to the outlet, used to house the differential pressure sensing valve. Finally, the main valve block has a receiving slot for housing... A signal sensor is used to detect the on / off state of the main control valve; the shut-off valve includes a shut-off spring, a shut-off valve cover, a shut-off valve core, a shut-off spring cone, and a shut-off valve core push rod. The shut-off valve cover is stepped, with one end disposed in the first stepped groove; one end of the shut-off valve core is disposed inside the shut-off valve cover, and the other end is connected to the shut-off valve core push rod, with the other end of the shut-off valve core push rod opposite to the push rod of the signal sensor; the shut-off spring cone is disposed inside the shut-off valve core, with one end of the shut-off spring connected to the shut-off spring cone and the other end connected to the shut-off valve cover.

2. The automatic shut-off valve for pipeline rupture as described in claim 1, characterized in that: The bottom of the shut-off valve cover is hexagonal prism-shaped, and its upper end has a first annular boss formed around its central axis. The first annular boss forms two axial stepped cavities, namely the first stepped cavity and the second stepped cavity from top to bottom. A first expansion cavity is formed between the first stepped cavity and the second stepped cavity. Two centrally symmetrical oblique channels are provided on the cavity wall of the first expansion cavity. A shut-off valve core back pressure cavity is formed between the shut-off valve cover and the shut-off valve core. The first expansion cavity and the second stepped cavity are components of the shut-off valve core back pressure cavity.

3. The automatic shut-off valve for pipeline rupture as described in claim 1, characterized in that: A damping hole is provided in the pipeline between the back pressure chamber of the shut-off valve core and the third switching valve port.

4. The automatic shut-off valve for pipeline rupture as described in claim 2, characterized in that: The differential pressure sensing valve includes a sensing valve cover, a sensing valve core, an adjusting screw, a sensing valve piston, a sensing spring seat, a sensing spring, a sensing spring cone, an automatic valve sleeve, and an automatic valve core. One end of the sensing valve cover is disposed in the second stepped groove, and one end of the sensing valve core is disposed in the sensing valve cover, with the other end connected to the automatic valve core. The automatic valve core is disposed in the automatic valve sleeve, which is disposed in the second stepped groove. The sensing valve piston is disposed in the sensing valve cover, with one end abutting against the adjusting screw and the other end connected to a sensing spring seat. The sensing spring cone is disposed in the sensing valve core. The two ends of the sensing spring are respectively connected to the sensing spring seat and the sensing spring cone. The high-pressure chamber is formed between the end of the sensing valve cover housed in the second stepped groove and the second stepped groove.

5. The automatic shut-off valve for pipeline rupture as described in claim 1, characterized in that: The mode switching valve includes a switching valve body, a switching valve sleeve, a switching valve core, a positioning sleeve, a centering spring, a centering spring seat, and an elastic retaining ring. The switching valve sleeve and the positioning sleeve are coaxially disposed within the switching valve body and abut against each other. Two centering spring seats are spaced apart within the positioning sleeve, and the two ends of the centering spring are respectively connected to the two centering spring seats. The elastic retaining ring is disposed adjacent to the centering spring seats and is located outside the positioning sleeve and inside the switching valve body. The switching valve core is located within the switching valve body, with one end passing sequentially through the switching valve sleeve, one centering spring seat, the centering spring, the other centering spring seat, and the elastic retaining ring, and the other end connected to a manual control lever.

6. The automatic shut-off valve for pipeline rupture as described in claim 5, characterized in that: The manual control lever includes a handle, a set screw, a handle spring, a handle limiting plate, a shift fork spindle, a shift fork, and a shift head. The handle limiting plate is connected to one side of the switching valve body and has a through circular hole for the shift fork spindle to pass through. One end of the shift fork spindle passes through the handle and extends into the switching valve body, connecting to one end of the shift fork. The other end of the shift fork is connected to the shift head, which is connected to the end of the switching valve core away from the centering spring seat. The handle spring and the set screw are both located in the handle near the circular hole. The two ends of the handle spring are respectively connected to the bottom of the inner groove of the handle and the set screw is housed in the inner groove.

7. A hydraulic system, characterized in that: The hydraulic system includes hydraulic pipelines and an automatic shut-off valve for pipeline rupture as described in any one of claims 1-6, wherein the automatic shut-off valve for pipeline rupture is connected in series in the hydraulic pipelines.

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