Automatic shut-off valve for pipeline damage and hydraulic system

Abstract

The invention belongs to the related technical field of hydraulic elements, and discloses a pipeline breakage automatic shut-off valve and a hydraulic system.The pipeline breakage automatic shut-off valve comprises a main control valve and a mode switching system, the main control valve comprises a main valve block, a differential pressure sensing valve arranged on the main valve block, 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 directional valve and a mode switching valve, and the mode switching valve and the electromagnetic directional valve are connected to the main valve block through a transition valve block; one end of the Pitot tube extends into the inlet, and the other end of the Pitot tube is communicated with a high-pressure cavity of the differential pressure sensing valve; the mode switching system is used for switching the working state of a shut-off valve through a mode switching valve and an electromagnetic directional valve in two control modes of manual control and hydraulic remote control; the main control valve senses the flow change through the Pitot tube and the differential pressure sensing valve so as to control opening and closing of the stop valve, and opening and closing of the shut-off valve are achieved.

Description

Technical Field

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

[0002] In existing hydraulic systems, pipelines serve as crucial channels for transmitting hydraulic oil, and their integrity is crucial to their proper operation. However, due to the complex and ever-changing operating environment of hydraulic systems, pipelines can become damaged by external forces, long-term vibration, corrosion, aging, and other factors. Once damaged, pipelines can cause large amounts of hydraulic oil to leak, resulting in not only energy waste and environmental pollution but also a rapid drop in system pressure, impacting equipment operation and potentially causing safety incidents.

[0003] However, existing designs typically use a flow coefficient to convert flow rate to pressure differential in flow calculations. However, this coefficient is affected by a variety of factors, making it difficult to accurately determine its value even with a defined structure. Consequently, precise device operation is difficult. Furthermore, conventional designs often utilize a purely automatic shutoff mode, preventing manual intervention to force the flow path open or close after system installation. This results in operational difficulties during emergencies or equipment maintenance. Summary of the Invention

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

[0005] To achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an automatic shut-off valve for pipeline damage, the shut-off valve comprising a mode switching system and a main control valve, the main control valve comprising a main valve block, a pressure differential sensing valve, a pitot tube and a stop valve arranged on the main valve block, the main valve block being provided with an inlet and an outlet; the mode switching system comprises an electromagnetic reversing valve and a mode switching valve, the mode switching valve and the electromagnetic reversing valve being connected to the main valve block through a transition valve block; the electromagnetic reversing valve is a three-position four-way electromagnetic reversing valve, the four valve ports of which are respectively connected to the right end and the left end of the mode switching valve, the high-pressure chamber of the pressure differential sensing valve and the oil drain port opened on the main valve block through the channels inside the transition valve block; the pitot tube is arranged in the main valve block with one end extending into the inlet and the other end extending into the inlet. The high-pressure chamber is connected; the right end of the pressure differential sensing valve is connected to the high-pressure chamber, and the left end is connected to the outlet, and its first sensing valve port and second sensing valve port are respectively connected to the oil 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 oil drain port and the high-pressure chamber; the mode switching system switches the working state of the shut-off valve in two control modes, manual control and hydraulic remote control, through the mode switching valve and the solenoid reversing valve; the main control valve senses flow changes through the Pitot tube and the pressure differential sensing valve, and then controls the switch 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 stop valve; the main valve block is also provided with a second stepped groove, which is connected to the outlet; the second stepped groove is used to accommodate the pressure differential sensing valve.

[0007] Furthermore, the main valve block is further provided with a receiving groove, the receiving groove is used to receive a signal sensor, and the signal sensor is used to detect the switching state of the main control valve.

[0008] Furthermore, the stop valve includes a stop spring, a stop valve cover, a stop valve core, a stop spring cone head and a stop valve core push rod. The stop valve cover is stepped, and one end of it is arranged in the first step groove; one end of the stop valve core is arranged in the stop valve cover, and the other end is connected to the stop valve core push rod, and the other end of the stop valve core push rod is arranged opposite to the push rod of the signal sensor; the stop spring cone head is arranged in the stop valve core, one end of the stop spring is connected to the stop spring cone head, and the other end is connected to the stop valve cover.

[0009] Furthermore, the bottom of the stop valve cover is hexagonal, and a first annular boss is formed on its upper end around its own central axis. The first annular boss forms two axial step cavities, which are the first step cavity and the second step cavity from top to bottom. A first diameter expansion cavity is formed between the first step cavity and the second step cavity, and two centrally symmetrical oblique channels are provided on the cavity wall of the first diameter expansion cavity; a stop valve core back pressure cavity is formed between the stop valve cover and the stop valve core, and the first diameter expansion cavity and the second step cavity are components of the stop valve core back pressure cavity.

[0010] Furthermore, a damping hole is provided on the pipeline between the back pressure chamber of the stop valve core and the third switching valve port.

[0011] Furthermore, the pressure differential 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 head, an automatic valve sleeve and an automatic valve core; one end of the sensing valve cover is arranged in the second stepped groove, one end of the sensing valve core is arranged in the sensing valve cover, and the other end is connected to the automatic valve core; the automatic valve core is arranged in the automatic valve sleeve, and the automatic valve sleeve is arranged in the second stepped groove; the sensing valve piston is arranged in the sensing valve cover, one end of which is in contact with the adjusting screw, and the other end is connected to one of the sensing spring seats, and the sensing spring cone head is arranged 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 head; the high-pressure chamber is formed between one end of the sensing valve cover accommodated 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 arranged in the switching valve body, and the two are abutted against each other; the two centering spring seats are arranged at intervals in 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 arranged adjacent to the centering spring seat and is located outside the positioning sleeve and in the switching valve body; the switching valve core is located in the switching valve body, one end of which passes through the switching valve sleeve, one centering spring seat, the centering spring, the other centering spring seat and the elastic retaining ring in sequence, and the other end is connected to the manual operating lever.

[0013] Furthermore, the manual operating lever includes a handle, a set screw, a handle spring, a handle limiting plate, a shift fork core shaft, a shift fork and a shift head. The handle limiting plate is connected to one side of the switching valve body and is provided with a through circular hole, and the circular hole is used for the shift fork core shaft to pass through; one end of the shift fork core shaft passes through the handle and extends into the switching valve body and is connected to one end of the shift fork, and the other end of the shift fork is connected to the shift head, and the shift head 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 arranged in one end of the handle adjacent to the circular hole, and 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 accommodated in one end of the inner groove.

[0014] The present invention further provides a hydraulic system, which includes a hydraulic pipeline and the pipeline damage automatic shut-off valve as described above, wherein the pipeline damage automatic shut-off valve is connected in series to the hydraulic pipeline.

[0015] In general, the above technical solutions conceived by the present invention, compared with the prior art, provide the pipeline damage automatic shut-off valve and hydraulic system with 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 reversing valve in two control modes: manual control and hydraulic remote control. The main control valve senses flow changes through the Pitot tube and the pressure differential sensing valve, thereby controlling the switch of the stop valve to open and close the shut-off valve. The present invention has two control modes: manual control and hydraulic remote control, and three working states: "normally open", "normally closed", and "automatic", achieving multi-scenario adaptability. Mode switching can be achieved regardless of on-site operation or remote control. Under various working conditions, the safe and stable operation of the pipeline system can be ensured, greatly improving reliability.

[0017] 2. The present invention adopts a damping hole to improve its shut-off characteristics. By adjusting the damping hole, different closing dynamic performances of the shut-off valve core and the induction valve core can be obtained, which plays a role in optimizing the shut-off speed of the shut-off valve core and enhancing stability. Its working stability is high and the adjustment range of the shut-off flow is large.

[0018] 3. This automatic shutoff valve first directs flow through a Pitot tube, where the sensing valve core senses flow changes and triggers the movement of the shutoff valve core. The Pitot tube converts flow rate to differential pressure without relying on a flow coefficient to determine the relationship between the two. This ensures that the automatic shutoff valve for pipeline damage accurately operates at the set cutoff flow value under various operating conditions, effectively improving flow control accuracy and reliability.

[0019] 4. The present invention realizes the setting of different shut-off flows by adjusting the preload force of the induction 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. The present invention is divided into independent modules such as the main control valve, transition valve block, and mode switching system, which are connected through standardized interfaces. The modular design supports rapid disassembly and replacement of components, shortens maintenance time, and can also adapt to different diameters by replacing modules.

[0021] 6. The present invention integrates the stop valve and the pressure differential sensing valve into one valve body of the main control valve, uses a transition valve block to connect the mode switching valve and the electromagnetic reversing valve, realizes functional linkage through the built-in flow channel, reduces external pipeline connections, has a compact structure, occupies little space, and has a low risk of leakage. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0023] Figure 2 yes Figure 1 A schematic diagram of the structure of the main control valve of the pipeline damage automatic shut-off valve;

[0024] Figure 3 yes Figure 1 A schematic diagram of the structure of the mode switching system of the pipeline damage automatic shut-off valve;

[0025] Figure 4 yes Figure 1 A schematic diagram of the structure of the mode switching valve of the pipeline damage automatic shut-off valve;

[0026] Figure 5 (a) and (b) are Figure 1 Working state diagram of pipeline damage automatic shut-off valve;

[0027] Figure 6 yes Figure 1 Schematic diagram of the structure of the manual operating lever of the pipeline breakage automatic shut-off valve.

[0028] In all the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 101 - signal sensor, 110 - main valve block, 111 - Pitot tube, 112 - inlet, 113 - outlet, 114 - oil drain port, 115 - inlet connector, 116 - outlet connector, 117 - high-pressure chamber, 118 - back-pressure chamber of shut-off valve core, 120 - shut-off valve, 121 - shut-off spring, 122 - shut-off valve cover, 123 - shut-off valve core, 124 - shut-off spring cone head, 125 - shut-off 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 head, 138 - sensing valve core hole Channel, 139-sensing valve cover hole, 141-automatic valve core, 142-automatic valve sleeve, 143-first sensing valve port, 144-second sensing valve port, 210-transition valve block, 220-manual joystick, 221-handle, 222-set screw, 223-handle spring, 224-handle limit plate, 225-fork core shaft, 226-fork, 227-switching head, 230-solenoid reversing 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 hole, 251-first switching valve port, 252-second switching valve port, 253-third switching valve port, 254-fourth switching valve port. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is 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 for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0030] See also Figure 1 and Figure 3The present invention provides an automatic shut-off valve for pipeline damage, the shut-off valve including a mode switching system and a main control valve. The main control valve includes a main valve block 110, a pressure differential sensing valve 130, a Pitot tube 111, and a stop valve 120 provided on the main valve block 110. The main valve block 110 is provided with an inlet 112 and an outlet 113. The mode switching system includes an electromagnetic reversing valve 230 and a mode switching valve 240. The mode switching valve 240 and the electromagnetic reversing valve 230 are connected to the main valve block 110 via a transition valve block 210. The solenoid reversing valve 230 is a three-position, four-way solenoid reversing valve. Its four valve ports are connected to the right and left ends of the mode switching valve 240, the high-pressure chamber 117 of the pressure differential sensing valve 130, and the oil drain port 114 of the main valve block 110, respectively, through passages within the transition valve block 210. A Pitot tube 111 is disposed within 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 pressure differential sensing valve 130 is connected to the high-pressure chamber 117, and the left end is connected to the outlet 113. Its first and second sensing valve ports 143 and 144 are connected to the oil drain port 114 and the second switching valve port 252 of the mode switching valve 240, respectively. 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 valve port 251 and the fourth switching valve port 254 of the mode switching valve 240 are connected to the oil drain port 114 and the high-pressure chamber 117 , respectively.

[0031] The mode switching valve 240 is a three-position, four-way valve, and the pressure differential sensing valve 130 is a two-position, three-way valve. The mode switching system uses the mode switching valve 240 and the solenoid reversing valve 230 to switch the shutoff valve's operating state 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 flow changes through the Pitot tube 111 and the pressure differential sensing valve 130, thereby controlling the opening and closing of the shutoff valve 120.

[0032] When in use, the shut-off valve is connected in series to the hydraulic system's pressure line. When the flow rate of the pipeline medium increases abnormally and exceeds the set value, it automatically disconnects the pressure line to protect the hydraulic source. The shut-off valve features automatic sensing switching, on-site manual control, and remote hydraulic control. It also features fast response and minimal pressure shock, effectively improving the safety and maintainability of the hydraulic system. It is suitable for various hydraulic systems to ensure stable operation.

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

[0034] The main valve block 110 is also provided with a first stepped groove, which connects the inlet 112 and the outlet 113. The first stepped groove is used to accommodate the stop 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 oil drain port 114, and both are perpendicular to the central axis of the inlet 112. The main valve block 110 is also provided with 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 joint 115, and the other end is connected to the high-pressure chamber 117 through a pipeline in the main valve block 110. The second stepped groove is used to accommodate the pressure differential sensing valve 130.

[0035] The main valve block 110 is further provided with a receiving groove for receiving a signal sensor 101 for detecting the on / off state of the main control valve. The receiving groove is connected to the first stepped groove, and the central axes of the two coincide with each other.

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

[0037] The bottom of the shutoff valve cover 122 is hexagonal in shape, with a first annular boss formed on its upper end around its central axis. This first annular boss defines two axial stepped cavities: 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 expanded cavity is formed between the first and second stepped cavities, with two centrally symmetrical oblique channels defined in its walls. A shutoff valve core backpressure chamber 118 is formed between the shutoff valve cover 122 and the shutoff valve core 123. The first expanded cavity and the second stepped cavity are integral components of the shutoff valve core backpressure chamber 118.

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

[0039] In this embodiment, a damping hole is opened on the pipeline between the stop valve core back pressure chamber 118 and the third switching valve port 253 , and is arranged 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 positioned within the second stepped groove. One end of the sensing valve core 132 is positioned within the sensing valve cover 131 and the other end is connected to the automatic valve core 141. The automatic valve core 141 is positioned within the automatic valve sleeve 142, which is positioned within the second stepped groove. The sensing valve piston 134 is positioned within the sensing valve cover 131, one end abutting the adjusting screw 133 and the other end connected to one of the sensing spring seats 135. The sensing spring cone 137 is positioned within the sensing valve core 132. The two ends of the sensing spring 136 are connected to the sensing spring seat 135 and the sensing spring cone 137, respectively. The high-pressure chamber 117 is formed between one end of the sensing valve cover 131 received 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, and 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, and 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. This axial through hole is a four-step stepped hole. From left to right, it consists of a coaxially connected first-step hole, a second-step hole, a third-step hole, and a fourth-step hole. The diameters of the holes decrease in this order. The first-step hole accommodates the adjusting screw 133, the second-step hole accommodates the sensing valve piston 134, and the fourth-step hole accommodates 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 on the top of the sensing spring cone 137 presses into the second conical groove defined in the sensing valve core 132. A sensing valve cover passage 139 is defined on the outer wall of the sensing valve cover 131, where it mates with the main valve block 110. The sensing valve core 132 communicates with the outlet 113 through the sensing valve core passage 138, the sensing valve cover passage 139, and the internal flow passage of the main valve block 110. The high-pressure chamber 117 communicates with the Pitot tube 111 through the internal flow passage of the main valve block 110.

[0044] A second boss is formed at the center of the outer top of the sensing valve core 132. A second boss is axially provided with a second-step U-shaped groove, with the outer groove diameter being smaller than the inner groove diameter. The second-step 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 groups of channels, each 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 medium flow in the pipeline does not exceed the set value, the sensing valve core 132 is maintained in the 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 oil drain port 114, and the shut-off valve core 123 remains open; when the medium flow in the pipeline exceeds the set value, the total pressure pushes the sensing valve core 132 to move 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 coordinated 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 an off state.

[0046] See also Figure 4 and Figure 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 a circlip. The switching valve sleeve 242 and the positioning sleeve 244 are coaxially disposed 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 ends of the centering spring 245 are connected to the two centering spring seats 246, respectively. The circlip is disposed 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 within the switching valve body 241. One end of the switching valve core 243 passes through the switching valve sleeve 242, one centering spring seat 246, the centering spring 245, the other centering spring seat 246, and the circlip in sequence. The other end is connected to the manual operating lever 220.

[0047] The switching valve body 241 defines a third stepped groove extending therethrough, within which the switching valve sleeve 242, the positioning sleeve 244, and the circlip are disposed. The switching valve sleeve 242 defines four sets of flow passages connected to its internal flow passages: 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 shut-off valve core back pressure chamber 118 with 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 is connected to the oil 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 is connected to the second switching valve port 252 through the internal flow channels of the main valve block 110 and the transition valve block 210, and the right side of the automatic valve core 141 is connected 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 is formed with three annular grooves. The two left reversing grooves each have four centrally symmetrical and evenly distributed switching valve core channels 247. These channels 247 connect to the corresponding two annular grooves through the flow path 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 right stepped shaft of the switching valve core 243. The centering spring 246 and the centering spring seat 246 are positioned integrally within the positioning sleeve 244.

[0049] See also Figure 6The manual operating lever 220 includes a handle 221, a set screw 222, a handle spring 223, a handle stop plate 224, a shift fork shaft 225, a shift fork 226, and a shift head 227. The handle stop plate 224 is attached to one side of the switching valve body 241 and has a circular hole therethrough for the shift fork shaft 225 to pass through. One end of the shift fork shaft 225 passes through the handle 221 and extends into the switching valve body 241, where it connects to 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 surfaces spaced 180° apart to mate with the fork-shaped groove of the shift fork 226. The square portion of the shift fork shaft 225 fits into the square hole of the shift fork 226. The handle spring 223 and the set screw 222 are both disposed within the end of the handle 221 adjacent to the circular hole. The ends of the handle spring 223 are connected to the bottom of the inner groove of the handle 221, while the set screw 222 is received within one end of the inner groove. During operation, turning the handle 221 rotates the shift fork core shaft 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 the three operating positions. The manual operating lever 220 is locked by adjusting the handle spring 223 via the set screw 222.

[0050] In the "automatic" mode, 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, where it is compared with the outlet static pressure and the preset spring force. According to the principle of the designed automatic shut-off valve for pipeline damage, the flow rate of the medium in the pipeline is positively correlated with the pressure differential. That is, the greater the flow rate, the greater the pressure differential. When the pipeline is working normally, the stop valve 120 is in the initial open state, the medium flows from the inlet 112 to the outlet 113 through the stop valve 120, and the sensing valve core 132 is in the right initial position. At this time, the back pressure chamber 118 of the stop valve core is connected with the oil drain port 114. Therefore, as long as the flow rate does not reach the set value of the sensing spring 136, the sensing valve core 132 and the stop valve core 123 will not 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 action of the pressure of the right high-pressure chamber 117, driving the automatic valve core 141 to move to the left, so that the comparison chamber is connected with the high-pressure chamber 117, so that the back pressure chamber 118 of the stop valve core is connected with the high-pressure chamber 117, causing the stop valve core 123 to move, cutting 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 forces the shut-off valve core back pressure chamber 118 to be connected with the oil drain port 114, and the shut-off valve core 123 is forced to open under the action of liquid 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 forces the shut-off valve core back pressure chamber 118 to be connected with the high-pressure chamber 117, and the shut-off valve core 123 is forced to close under the action of liquid pressure, and the shut-off valve core 123 cuts off the flow path of the main control valve, and the automatic shut-off valve for pipeline damage is in the "normally closed" working state.

[0052] When power is removed from both ends of the solenoid reversing valve 230, there is no hydraulic pressure acting on both ends of the mode switching valve 240, allowing manual control. Manual lever 220 is used to move the switching valve core 243 between three operating positions. When the manual lever 220 is locked in the neutral position, remote hydraulic control is enabled. The solenoid reversing valve 230 is controlled by an electrical signal. The solenoid reversing valve 230 directs oil from the main control valve's high-pressure chamber 117 and oil drain port 114 to both ends of the mode switching valve 240, controlling the pressure and thus switching the operating positions of the mode switching valve 240. When manual control or remote hydraulic control is not in effect, the switching valve core 243 returns to its original position under the action of a spring, and the automatic shut-off valve for pipeline damage is in the "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 passage.

[0053] The compression amount of the sensing spring 136 of the pipeline damage automatic shut-off valve can be changed by adjusting the screw 133 in the automatic working state, thereby fine-tuning the flow rate generated by the switching of the stop valve core 123.

[0054] The present invention further provides a hydraulic system, which includes a hydraulic pipeline and the pipeline damage automatic shut-off valve as described above, wherein the pipeline damage automatic shut-off valve is connected in series to the hydraulic pipeline.

[0055] It will be easily understood by those skilled in the art 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 in the scope of protection of the present invention.

Claims

1. A pipeline damage automatic shut-off valve, characterized by: The shut-off valve includes a mode switching system and a main control valve, the main control valve includes a main valve block, a pressure differential sensing valve, a Pitot tube and a shut-off valve arranged on the main valve block, and the main valve block is provided with an inlet and an outlet; the mode switching system includes an electromagnetic reversing valve and a mode switching valve, the mode switching valve and the electromagnetic reversing valve are connected to the main valve block through a transition valve block; the electromagnetic reversing valve is a three-position four-way electromagnetic reversing valve, and its four valve ports are respectively connected to the right end and the left end of the mode switching valve, the high-pressure chamber of the pressure differential sensing valve and the oil drain port opened on the main valve block through the channels inside the transition valve block; the Pitot tube is arranged in the main valve block and one end extends into the inlet, and the other end is connected to the high-pressure chamber; the right end of the pressure differential sensing valve is connected to In the high-pressure chamber of the mode switching valve, the left end is connected to the outlet, and its first sensing valve port and second sensing valve port are respectively connected to the oil 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 oil drain port and the high-pressure chamber; the mode switching system switches the working state of the shut-off valve in two control modes, manual control and hydraulic remote control, through the mode switching valve and the solenoid reversing valve; the main control valve senses flow changes through the Pitot tube and the pressure differential sensing valve, and then controls the switch of the shut-off valve to realize the opening and closing of the shut-off valve.

2. The pipeline damage automatic shut-off valve according to claim 1, characterized in that: 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 stop valve; the main valve block is also provided with a second stepped groove, which is connected to the outlet; the second stepped groove is used to accommodate the pressure differential sensing valve.

3. The pipeline damage automatic shut-off valve according to claim 1, characterized in that: The main valve block is further provided with a receiving groove, and the receiving groove is used to receive a signal sensor, and the signal sensor is used to detect the switching state of the main control valve.

4. The pipeline damage automatic shut-off valve according to claim 2, characterized in that: The stop valve includes a stop spring, a stop valve cover, a stop valve core, a stop spring cone head and a stop valve core push rod. The stop valve cover is stepped, and one end of it is arranged in the first step groove; one end of the stop valve core is arranged in the stop valve cover, and the other end is connected to the stop valve core push rod, and the other end of the stop valve core push rod is arranged opposite to the push rod of the signal sensor; the stop spring cone head is arranged in the stop valve core, one end of the stop spring is connected to the stop spring cone head, and the other end is connected to the stop valve cover.

5. The pipeline damage automatic shut-off valve according to claim 4, characterized in that: The bottom of the stop valve cover is hexagonal, and a first annular boss is formed on its upper end around its own central axis. The first annular boss forms two axial step cavities, which are the first step cavity and the second step cavity from top to bottom. A first diameter expansion cavity is formed between the first step cavity and the second step cavity, and two centrosymmetrical oblique channels are provided on the cavity wall of the first diameter expansion cavity; a stop valve core back pressure cavity is formed between the stop valve cover and the stop valve core, and the first diameter expansion cavity and the second step cavity are components of the stop valve core back pressure cavity.

6. The pipeline damage automatic shut-off valve according to claim 1, characterized in that: A damping hole is provided on the pipeline between the back pressure chamber of the stop valve core and the third switching valve port.

7. The pipeline damage automatic shut-off valve according to claim 5, characterized in that: The pressure differential 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 head, an automatic valve sleeve and an automatic valve core; one end of the sensing valve cover is arranged in the second stepped groove, one end of the sensing valve core is arranged in the sensing valve cover, and the other end is connected to the automatic valve core; the automatic valve core is arranged in the automatic valve sleeve, and the automatic valve sleeve is arranged in the second stepped groove; the sensing valve piston is arranged in the sensing valve cover, one end of which abuts the adjusting screw, and the other end is connected to one of the sensing spring seats, and the sensing spring cone head is arranged 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 head; the high-pressure chamber is formed between the end of the sensing valve cover accommodated in the second stepped groove and the second stepped groove.

8. The pipeline damage automatic shut-off valve according to 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 arranged in the switching valve body and the two are in contact with each other; the two centering spring seats are spaced apart in 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 arranged adjacent to the centering spring seat and is located outside the positioning sleeve and in the switching valve body; the switching valve core is located in the switching valve body, one end of which passes through the switching valve sleeve, one centering spring seat, the centering spring, the other centering spring seat and the elastic retaining ring in sequence, and the other end is connected to the manual operating lever.

9. The pipeline damage automatic shut-off valve according to claim 8, characterized in that: The manual operating lever includes a handle, a set screw, a handle spring, a handle limiting plate, a shift fork core shaft, a shift fork and a shift head. The handle limiting plate is connected to one side of the switching valve body and is provided with a through circular hole for allowing the shift fork core shaft to pass through. One end of the shift fork core shaft passes through the handle and extends into the switching valve body and is connected to one end of the shift fork. The other end of the shift fork is connected to the shift head, and the shift head is connected to an end of the switching valve core away from the centering spring seat. The handle spring and the set screw are both arranged in one end of the handle adjacent to the circular hole, and 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 accommodated in one end of the inner groove.

10. A hydraulic system, characterized in that: The hydraulic system includes a hydraulic pipeline and the pipeline damage automatic shut-off valve according to any one of claims 1 to 9, and the pipeline damage automatic shut-off valve is connected in series to the hydraulic pipeline.

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