Hydraulic line leak lock system

Abstract

The application discloses a hydraulic pipeline leakage self-locking system, which comprises a first reversing valve and a second reversing valve. Two interfaces on one side of the first reversing valve are connected to a high-pressure oil source and an oil tank respectively, and two interfaces on the other side of the first reversing valve are connected to a rod cavity and a rodless cavity of an oil cylinder through two oil paths respectively. The two oil paths are sequentially provided with a one-way throttling valve, a logic valve and a hydraulic control one-way valve connected in parallel from the first reversing valve to the oil cylinder. Two interfaces on one side of the second reversing valve are connected to the high-pressure oil source and the oil tank respectively, one interface on the other side of the second reversing valve is connected to the control end of the hydraulic control one-way valve on the two oil paths respectively, and the other interface is locked. The first reversing valve is used for changing the movement direction of the oil cylinder, the one-way throttling valve is used for adjusting the movement speed of the oil cylinder, the second reversing valve is used for controlling the opening of the hydraulic control one-way valve, and the logic valve and the hydraulic control one-way valve are used for quickly cutting off the hydraulic circuit when the pipeline leaks. The system directly cuts off the pipeline by using hydraulic components, and does not affect the operation of other circuits.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic technology, specifically relating to a self-locking system for hydraulic pipeline leakage. Background Technology

[0002] Hydraulic systems are widely used in many industrial fields. Due to their high load capacity and high power per unit volume, hydraulic systems are generally used in heavy industrial production and mobile machinery. However, the large load capacity, small size, and high pipeline pressure of hydraulic systems make them prone to oil leaks at hose joints and other parts. If a leak is not detected in time, the hydraulic station may stop due to low oil level, affecting production. This is especially true in operating conditions with only lifting and lowering without a stop position, because the directional valve cannot cut off the oil supply. Once a leak occurs, the oil level will continue to drop until the pump stops unless the ball valve is manually closed. In the high-temperature environment of the metallurgical industry, hose rubber and joint seals are prone to aging and failure. Once damaged, hydraulic oil can easily spray out. In the high-temperature zone of steelmaking continuous casting, hydraulic oil encountering the high-temperature casting billet will inevitably cause a fire, resulting in huge economic losses and safety accidents.

[0003] Currently, oil leaks in hydraulic systems are mainly prevented through routine checks of hoses and joints, as well as monitoring changes in the oil tank level. However, for sudden leaks, the usual method is to manually close the ball valve or shut-off valve after the incident is observed. This method is inefficient, slow to react, and can easily cause significant losses. Summary of the Invention

[0004] The purpose of this invention is to provide a hydraulic pipeline leakage self-locking system. This system uses hydraulic components to directly cut off the pipeline without other detection elements, which facilitates inspection and maintenance, does not affect the operation of other circuits, and can automatically reset. It is suitable for use in hydraulic systems that require long-term pressure maintenance.

[0005] The technical solution adopted in this invention is:

[0006] A hydraulic pipeline leakage self-locking system includes a first directional valve and a second directional valve. Two ports on one side of the first directional valve are connected to a high-pressure oil source and an oil tank, respectively. Two ports on the other side are connected to the rod-side and rodless-side chambers of a hydraulic cylinder via two oil circuits. Each oil circuit has a one-way throttle valve and a parallel logic valve and a hydraulically controlled check valve sequentially arranged from the first directional valve toward the hydraulic cylinder. Two ports on one side of the second directional valve are connected to the high-pressure oil source and an oil tank, respectively. One port on the other side of the second directional valve is connected to the control terminal of the hydraulically controlled check valve on each of the two oil circuits, and the other port is locked. The first directional valve is used to change the direction of hydraulic cylinder movement, the one-way throttle valve is used to adjust the speed of hydraulic cylinder movement, and the second directional valve is used to control the opening of the hydraulically controlled check valve. The logic valve and the hydraulically controlled check valve work together to quickly cut off the hydraulic circuit in the event of a pipeline leak.

[0007] Furthermore, when the system starts running, the logic valve spool is in the cut-off position. To open the oil circuit, the second directional valve switches to the parallel position, and the hydraulic check valve opens. After the cylinder completes its movement, the second directional valve switches back to the cross position, the hydraulic check valve closes, and the pressure oil flowing towards the cylinder is maintained by the logic valve. The return oil flows back to the oil tank through the hydraulic check valve, the one-way throttle valve, and the first directional valve. When the cylinder resets and builds pressure again after being switched by the first directional valve or cut off by the logic valve, the second directional valve switches to the parallel position, the hydraulic check valve opens, and after the action or pressure build-up is completed, the second directional valve switches back to the cross position, and the logic valve is put into use.

[0008] Furthermore, the logic valve has a 1# oil port, a 2# oil port, and a 3# oil port. The 1# and 2# oil ports serve as oil circuit ports and respectively lead out control oil to act on the valve core. The 2# oil port is located near the cylinder end, and the 3# oil port serves as the control oil port and is directly connected to the oil circuit outlet. The working range of the logic valve is adjusted by setting the area ratio of the control ends of the 1#, 2#, and 3# oil ports and the spring force of the 3# oil port.

[0009] Furthermore, the area ratio of the control terminals of oil ports #1, #2, and #3 is 5:4:9; let the pressure at oil port #1 be x (bar), the pressure at oil port #2 be y (bar), and the spring force at oil port #3 be 20 (bar). Then, the control pressure at the logic valve's off position is F1 = 5x + 4y (bar), the control pressure at the logic valve's on position is F2 = 9y + 20 (bar), and the pressure difference between the two control oil ports is ΔF = F2 - F 1 = 5y - 5x + 20; When the cylinder is in position and there is no leakage in the pipeline, the pressure at ports 1, 2, and 3 is the same, i.e., x = y. Then ΔF = 20 > 0, and the logic valve core is in the open position. When a leak occurs in the pipeline, the pressure at port 2 will decrease. Once ΔF < 0, i.e., y + 4 < x, the logic valve core is in the cut-off position, the oil circuit is cut off, the pressure at port 2 drops to 0, the logic valve is completely closed, and the leakage stops.

[0010] Furthermore, both oil circuits are equipped with pressure testing connectors at the oil cylinder connection points. These connectors are used to connect external pressure testing equipment to display the oil cylinder pressure.

[0011] The beneficial effects of this invention are:

[0012] This system utilizes logic valves and hydraulically controlled check valves to disconnect and reconnect leaking pipelines, making it particularly suitable for hydraulic systems requiring long-term pressure maintenance. It directly cuts off pipelines using hydraulic components, eliminating the need for other detection elements. The shut-off valve assembly can be installed on the valve platform along with the control valve assembly for easy inspection and maintenance. Each pipeline is controlled independently; in the event of a leak, only the current circuit is disconnected, without affecting the operation of other circuits. After pipeline repairs are completed, it can be automatically reset via a second solenoid directional valve, allowing for rapid resumption of production. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a current hydraulic system.

[0014] Figure 2 This is a schematic diagram of the hydraulic pipeline leakage self-locking system in an embodiment of the present invention.

[0015] In the diagram: 1-First directional valve; 2-Second directional valve; 3-One-way throttle valve; 4-Logic valve; 5-Hydraulic check valve; 6-Pressure test connector; 7-Hydraulic cylinder. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] like Figure 1 The diagram shown is a schematic of a commonly used hydraulic system. Figure 2 The diagram shows a schematic of a hydraulic pipeline leakage self-locking system provided by the present invention. It includes a first directional valve 1 and a second directional valve 2. Two ports on one side of the first directional valve 1 are connected to a high-pressure oil source and an oil tank, respectively. Two ports on the other side are connected to the rod-side and rodless-side chambers of the cylinder 7 via two oil circuits. Each oil circuit has a one-way throttle valve 3 and a parallel logic valve 4 and a hydraulically controlled check valve 5 sequentially arranged from the first directional valve 1 towards the cylinder 7. Two ports on one side of the second directional valve 2 are connected to a high-pressure oil source and an oil tank, respectively. One port on the other side of the second directional valve 2 is connected to the control end of the hydraulically controlled check valve 5 on each of the two oil circuits, and the other port is locked. The first directional valve 1 is used to change the direction of movement of the cylinder 7, the one-way throttle valve 3 is used to adjust the speed of movement of the cylinder 7, and the second directional valve 2 is used to control the opening of the hydraulically controlled check valve 5. The logic valve 4 and the hydraulically controlled check valve 5 work together to quickly cut off the hydraulic circuit in case of pipeline leakage.

[0018] In this invention, when the system starts running, the valve core of logic valve 4 is in the cut-off position. To open the oil circuit, the second directional valve 2 switches to the parallel position, and the hydraulic check valve 5 opens. After the cylinder 7 completes its movement, the second directional valve switches back to the cross position, and the hydraulic check valve closes. The pressure oil flowing towards the cylinder 7 is maintained by logic valve 4, and the return oil returns to the oil tank through the hydraulic check valve 5, the one-way throttle valve 3, and the first directional valve 1. When the cylinder 7 resets and builds pressure again after being switched by the first directional valve 1 or cut off by logic valve 4, the second directional valve 2 switches to the parallel position, and the hydraulic check valve 5 opens. After the action is completed or the pressure is built up, the second directional valve switches back to the cross position, and logic valve 4 is put into use.

[0019] like Figure 2As shown, in this embodiment, the logic valve 4 has a 1# oil port, a 2# oil port, and a 3# oil port. The 1# and 2# oil ports serve as oil circuit ports and respectively lead out control oil to act on the valve core. The 2# oil port is located near the cylinder end, and the 3# oil port serves as a control oil port directly connected to the outlet of the oil circuit. The working range of the logic valve 4 is adjusted by setting the area ratio of the control ends of the 1#, 2#, and 3# oil ports and the spring force of the 3# oil port.

[0020] In this embodiment, the area ratio of the control terminals of oil ports 1#, 2#, and 3# is 5:4:9; let the pressure of oil port 1# be x (bar), the pressure of oil port 2# be y (bar), and the spring force of oil port 3# be 20 (bar). Then, the control pressure of logic valve 4 at the cut-off position is F1 = 5x + 4y (bar), the control pressure of logic valve 4 at the open position is F2 = 9y + 20 (bar), and the pressure difference between the two ends is ΔF = F2 - F 1 = 5y - 5x + 20; When the cylinder 7 is in position and there is no leakage in the pipeline, the pressure at ports 1, 2 and 3 is the same, i.e., x = y. Then ΔF = 20 > 0, and the valve core of logic valve 4 is in the open position. When a leak occurs in the pipeline, the pressure at port 2 will decrease. Once ΔF < 0, i.e., y + 4 < x, the valve core of logic valve 4 is in the cut-off position, the oil circuit is cut off, the pressure at port 2 drops to 0, logic valve 4 is completely closed, and the leakage stops.

[0021] like Figure 2 As shown, in this embodiment, both oil circuits are equipped with pressure testing connectors 6 at the connection points to the oil cylinder 7. The pressure testing connectors 6 are used to connect external pressure detection equipment to display the pressure of the oil cylinder 7.

[0022] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A hydraulic pipeline leakage self-locking system, characterized in that: The system includes a first directional valve and a second directional valve. The first directional valve has two ports on one side connected to a high-pressure oil source and an oil tank, respectively. The other two ports on the other side are connected to the rod-side and rodless-side chambers of the hydraulic cylinder via two oil circuits. Each oil circuit has a one-way throttle valve, a parallel logic valve, and a hydraulically controlled check valve sequentially arranged from the first directional valve towards the hydraulic cylinder. The second directional valve has two ports on one side connected to a high-pressure oil source and an oil tank, respectively. One port on the other side of the second directional valve is connected to the control terminal of the hydraulically controlled check valve on each of the two oil circuits, and the other port is locked. The first directional valve is used to change the direction of the hydraulic cylinder's movement, the one-way throttle valve is used to adjust the speed of the hydraulic cylinder's movement, and the second directional valve is used to control the opening of the hydraulically controlled check valve. The logic valve and the hydraulically controlled check valve work together to quickly cut off the hydraulic circuit in case of pipeline leakage. When the system starts running, the logic valve spool is in the cut-off position. To open the oil circuit, the second directional valve switches to the parallel position, and the hydraulic check valve opens. After the cylinder completes its movement, the second directional valve switches back to the cross position, the hydraulic check valve closes, and the pressure oil flowing towards the cylinder is maintained by the logic valve. The return oil flows back to the oil tank through the hydraulic check valve, the one-way throttle valve, and the first directional valve. When the cylinder resets and builds pressure again after being switched by the first directional valve or cut off by the logic valve, the second directional valve switches to the parallel position, the hydraulic check valve opens, and after the action or pressure build-up is completed, the second directional valve switches back to the cross position, and the logic valve is put into use. The logic valve has ports #1, #2, and #3. Ports #1 and #2 serve as oil circuit ports and lead out control oil to the valve core. Port #2 is located near the cylinder end, and port #3 serves as the control oil port, directly connected to the oil circuit outlet. The operating range of the logic valve is adjusted by setting the area ratio of the control ends of ports #1, #2, and #3, as well as the spring force of port #3.

2. The hydraulic pipeline leakage self-locking system as described in claim 1, characterized in that: The area ratio of the control terminals of oil ports 1#, 2#, and 3# is 5:4:

9. Let the pressure at oil port 1# be x (bar), the pressure at oil port 2# be y (bar), and the spring force at oil port 3# be 20 (bar). Then, the control pressure of the logic valve in the off position is F1=5x+4y (bar), the control pressure of the logic valve in the on position is F2=9y+20 (bar), and the pressure difference between the two ends is ΔF=F2-F1=5y-5x+20. When the cylinder moves to the correct position and there is no leakage in the pipeline, the pressures at oil ports 1#, 2#, and 3# are the same, i.e., x=y. Therefore, ΔF=20>0, and the logic valve core is in the on position. When a leak occurs in the pipeline, the pressure at oil port 2# will decrease. Once ΔF<0, i.e., y+4<x, the logic valve core is in the off position, the oil circuit is cut off, the pressure at oil port 2# drops to 0, the logic valve is completely closed, and the leakage stops.

3. The hydraulic pipeline leakage self-locking system as described in claim 1, characterized in that: Both oil circuits are equipped with pressure test connectors at the oil cylinder connection points. These connectors are used to connect external pressure testing equipment to display the oil cylinder pressure.

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