Control oil way of pilot-operated type electromagnetic relief valve

Abstract

The invention provides a control oil way of a pilot-operated type electromagnetic relief valve, belongs to the technical field of valve control, and solves the problem that in the prior art, troubleshooting is time-consuming. The main valve comprises an electromagnetic valve e and a main valve element, the main valve element is communicated with a valve element position monitoring electromagnetic valve, a damper c is arranged between the valve element position monitoring electromagnetic valve and the main valve element, and a bypass pipeline and a direct-acting overflow valve are communicated between the valve element position monitoring electromagnetic valve and the damper c; an inlet of the electromagnetic valve e is connected with a pressure sensor b, a pressure sensor a is connected between the damping b and the damping d, a pressure sensor c is connected between the damping a and the damping b, a pressure sensor e is connected between the valve element position monitoring electromagnetic valve and the damping c, and a pressure sensor d is connected between the damping c and the main valve element. The valve element position monitoring electromagnetic valve monitors the position of a valve element of the valve element position monitoring electromagnetic valve, the fault position can be judged through cooperation of the valve element position monitoring electromagnetic valve and the pressure sensors, the fault checking time is shortened, and normal operation of equipment is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of valve control, and in particular to a control oil circuit of a pilot electromagnetic overflow valve. Background Art

[0002] Relief valves are installed in hydraulic systems in the fields of industrial automation, water conservancy, electric power, engineering machinery, machine tools, wind power generation, metallurgy, petrochemicals, etc. Pilot-operated electromagnetic relief valves are installed in medium and large flow output occasions. Pilot-operated electromagnetic relief valves play a pivotal role in the safe and stable operation of the entire hydraulic system. During operation, when the system pressure is too high, the relief valve automatically overflows to prevent damage to the equipment caused by excessive system pressure; when the system is not working or in standby mode, the pilot-operated electromagnetic relief valve unloads, reducing energy consumption and system heating, and extending the service life of the equipment.

[0003] In the hydraulic system, the pilot electromagnetic relief valve is set in the system circuit in a bypass manner. A large number of engineering applications have shown that although the system is equipped with a filter, electromagnetic relief valve failures occur from time to time, resulting in shutdown to replace the relief valve or shutdown to troubleshoot the fault. Shutdown for troubleshooting is more common. For equipment that requires continuous operation, does not allow long-term shutdown, and MTTR (mean time to repair) assessment indicators, it will cause greater economic losses. Troubleshooting usually adopts the elimination method, from electrical to sliding valve core, to damping hole, to direct-acting relief valve, main valve core, etc., a series of operations are relatively troublesome, consuming manpower and material resources, and the troubleshooting time cannot be scientifically controlled, affecting the normal operation of the equipment. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a control oil circuit of a pilot-operated electromagnetic overflow valve. The valve core position monitoring solenoid valve monitors its own valve core position, and cooperates with various pressure sensors to determine the location of the fault, so as to shorten the fault troubleshooting time and ensure the normal operation of the equipment.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A control oil circuit of a pilot-operated electromagnetic overflow valve comprises an electromagnetic valve e and a main valve core, wherein the inlet of the electromagnetic valve e is connected to a P1 port for oil inlet of a system, the oil inlet of the main valve core is connected to an outlet of the electromagnetic valve e, the oil outlet of the main valve core is connected to a T port for oil outlet of the system through a pipeline, one end of the main valve core away from the oil inlet is connected to a valve core position monitoring electromagnetic valve connected to the T port through a pipeline, a damper c is arranged in the pipeline between the valve core position monitoring electromagnetic valve and the main valve core, and a damper c is arranged between the valve core position monitoring electromagnetic valve and the damper c The pipeline between is connected with a bypass pipeline and a direct-acting overflow valve connected with port T, the pipeline between the solenoid valve e and the main valve core is connected with the bypass pipeline, and damping a, damping b and damping d are arranged in sequence in the bypass pipeline; the inlet of the solenoid valve e is connected with a pressure sensor b, the damping b and the damping d are connected with a pressure sensor a, the damping a and the damping b are connected with a pressure sensor c, the valve core position monitoring solenoid valve is connected with a pressure sensor e and the damping c, and the damping c and the main valve core are connected with a pressure sensor d.

[0007] Preferably, the pressure sensor a is connected to the T port through a pipeline and a solenoid valve a is provided in the pipeline, the side of the pressure sensor a away from the solenoid valve a is connected to the P1 port through a pipeline and a solenoid valve c is provided in the pipeline, the pressure sensor c is connected to the T port through a pipeline and a solenoid valve b is provided in the pipeline, the pressure sensor c is connected to the P1 port through a pipeline and a solenoid valve d is provided in the pipeline, the pressure sensor d is connected to the T port through a pipeline and a solenoid valve f is provided in the pipeline, and the pressure sensor e is connected to the P1 port through a pipeline and a solenoid valve g is provided in the pipeline.

[0008] Preferably, the solenoid valve a, solenoid valve b, solenoid valve c, solenoid valve d, solenoid valve e, solenoid valve f and solenoid valve g are all solenoid ball valves.

[0009] Preferably, a pipeline connecting the solenoid valve e and the P1 port is connected to a connecting pipe connected to the T port, and a safety valve is provided in the connecting pipe.

[0010] Preferably, the P1 port is connected to a P2 port for delivering oil to the actuator circuit.

[0011] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0012] The valve core position monitoring solenoid valve monitors its own valve core position and can determine the location of the fault in conjunction with various pressure sensors to shorten the troubleshooting time and ensure the normal operation of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 A schematic diagram of a flow chart provided for an embodiment of the present invention.

[0015] Figure markings: 1-solenoid valve a; 2-pressure sensor a; 3-solenoid valve b; 4-solenoid valve c; 5-solenoid valve d; 6-pressure sensor b; 7-pressure sensor c; 8-damping a; 9-damping b; 10-damping c; 11-damping d; 12-valve core position monitoring solenoid valve; 13-direct-acting overflow valve; 14-main valve core; 15-solenoid valve e; 16-pressure sensor d; 17-solenoid valve f; 18-safety valve; 19-pressure sensor e; 20-solenoid valve g; 21-bypass pipe; 22-connecting pipe. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] In the description of the present invention, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0019] Combine the following Figure 1 The present invention is described in detail.

[0020] Example

[0021] A control oil circuit of a pilot-operated electromagnetic overflow valve comprises an electromagnetic valve e15 and a main valve core 14, wherein the inlet of the electromagnetic valve e15 is connected to the P1 port for oil inlet of the system, the oil inlet of the main valve core 14 is connected to the outlet of the electromagnetic valve e15, the oil outlet of the main valve core 14 is connected to the T port for oil outlet of the system through a pipeline, the end of the main valve core 14 away from the oil inlet is connected to the valve core position monitoring electromagnetic valve 12 communicated with the T port through a pipeline, a damping c10 is arranged in the pipeline between the valve core position monitoring electromagnetic valve 12 and the main valve core 14, and the pipeline between the valve core position monitoring electromagnetic valve 12 and the damping c10 is connected to The bypass pipe 21 and the direct-acting overflow valve 13 communicated with the T port, the pipe between the solenoid valve e15 and the main valve core 14 are communicated with the bypass pipe 21, and the damping a8, the damping b9 and the damping d11 are arranged in sequence in the bypass pipe 21; the inlet of the solenoid valve e15 is connected with the pressure sensor b6, the pressure sensor a2 is connected between the damping b9 and the damping d11, the pressure sensor c7 is connected between the damping a8 and the damping b9, the pressure sensor e19 is connected between the valve core position monitoring solenoid valve 12 and the damping c10, and the pressure sensor d16 is connected between the damping c10 and the main valve core 14.

[0022] An oil inlet A is provided at the lower end of the main valve core 14, a connecting port C is provided at the upper end of the main valve core 14, and an oil outlet B is provided on the side wall of the main valve core 14; a piston is slidably provided in the main valve core 14, the piston separates the oil inlet A and the connecting port C, and a spring is connected to the upper end surface of the piston, the spring assists the piston in resetting and cuts off the connection between the oil inlet A and the oil outlet B. Figure 1 There are black dots at the intersections of the middle line segments to indicate that they are connected.

[0023] The pressure sensor a2 is connected to the T port through a pipeline and a solenoid valve a1 is provided in the pipeline. The side of the pressure sensor a2 away from the solenoid valve a1 is connected to the P1 port through a pipeline and a solenoid valve c4 is provided in the pipeline. The pressure sensor c7 is connected to the T port through a pipeline and a solenoid valve b3 is provided in the pipeline. The pressure sensor c7 is connected to the P1 port through a pipeline and a solenoid valve d5 is provided in the pipeline. The pressure sensor d16 is connected to the T port through a pipeline and a solenoid valve f17 is provided in the pipeline. The pressure sensor e19 is connected to the P1 port through a pipeline and a solenoid valve g20 is provided in the pipeline. By setting the above-mentioned solenoid valves, the oil can be reversely flushed and damped; after the fault location is found, there is no need to stop the hydraulic system, and no manual operations such as manual disassembly, cleaning, and purging are required, which is more convenient and quick.

[0024] Solenoid valve A1, solenoid valve B3, solenoid valve C4, solenoid valve D5, solenoid valve E15, solenoid valve F17 and solenoid valve G20 are all solenoid ball valves. Among them, solenoid valve E15 is a normally open solenoid ball valve, and the other solenoid ball valves are normally closed solenoid ball valves. Solenoid ball valves have good sealing performance and fast response speed.

[0025] The pipe connecting the solenoid valve e15 and the P1 port is connected to a connecting pipe 22 connected to the T port, and a safety valve 18 is arranged in the connecting pipe 22. The maximum working pressure of the flushing is set to protect the system. The setting pressure of the safety valve 18 is the same as the setting pressure of the pilot electromagnetic relief valve.

[0026] The P1 port is connected to the P2 port for delivering oil to the actuator circuit.

[0027] The pilot electromagnetic overflow valve can increase or decrease the number of damping in the bypass pipe 21 according to demand, and the number of electromagnetic valves and pressure sensors will be adjusted accordingly. Since the pilot electromagnetic overflow valve involved in this application has three damping settings in the bypass pipe 21, this application describes this type of pilot electromagnetic overflow valve.

[0028] The main types of pilot-operated electromagnetic relief valve failures are abnormal loading, pressure exceeding normal values, slow pressure relief, and inability to unload. The damping hole inside the valve is small in diameter, and the valve core of the position monitoring solenoid valve is a slide valve. If the system oil cleanliness is not properly controlled, it is easy to cause the damping hole to be blocked and the slide valve to be stuck. All of the above will lead to various failures.

[0029] The valve core position monitoring solenoid valve 12 is a normally open solenoid valve, which is internally equipped with a device for monitoring the position of the solenoid valve core. The device can monitor the two working positions of the valve core, thereby determining whether the solenoid valve core is stuck, whether the solenoid coil or the plug is damaged, and then accurately replacing it without affecting the production progress of the equipment.

[0030] Fault judgment process and flushing process:

[0031] 1. System no-load start

[0032] Solenoid valve a1, solenoid valve b3, solenoid valve c4, solenoid valve d5, solenoid valve f17 and solenoid valve g20 remain in the closed state, and solenoid valve e15 and valve core position monitoring solenoid valve 12 remain in the open state; after the system oil passes through the solenoid valve e15 from the P1 port, the oil is divided into a control oil path through the damping a8, damping b9 and damping d11 to enter the valve core position monitoring solenoid valve 12, and the control oil passes through the valve core position monitoring solenoid valve 12 to the T port and then returns to the hydraulic oil tank; at the same time, a pressure difference is generated at both ends of the damping c10, the balancing force on the main valve spool 14 is broken, and the spool is immediately lifted up, and the system oil enters the oil outlet B from the oil inlet A to the T port and returns to the oil tank. At this time, the system is circulating at no load.

[0033] 2. System loading

[0034] The system cycles for 5-10 seconds without load, and the valve core position monitoring solenoid valve 12 is closed. At this time, the valve core of the valve core position monitoring solenoid valve 12 moves to another working position, and feedback information is received. The control oil valve core position monitoring solenoid valve 12 is blocked, and the system begins to build up pressure. As the pressure gradually increases, when the control oil pressure exceeds the set value of the direct-acting relief valve 13, the direct-acting relief valve 13 begins to overflow, and a certain pressure difference is generated at both ends of the damping c10. The main valve core 14 is partially lifted, and the system oil enters the oil outlet B from the oil inlet A to reach the T port, thereby maintaining the system pressure at the set value of the direct-acting relief valve 13; when the system pressure is lower than the set value of the direct-acting relief valve 13, the direct-acting relief valve 13 is closed, and the valve core of the main valve core 14 returns to the valve seat under the action of the spring force and the control oil, and the main valve core 14 is closed.

[0035] 3. System loading abnormality

[0036] 3.1. The valve core position monitoring solenoid valve 12 is closed and the system has no pressure. At this time, if the position monitoring of the valve core position monitoring solenoid valve 12 does not send a signal, it can be determined that the valve core of the valve core position monitoring solenoid valve 12 has no action. There are three factors for the valve core to not move: the first factor is that the electrical plug has no electrical signal; the second factor is that the valve core is stuck; the third factor is that the electromagnetic coil is faulty. Through the pre-set P1 LC program, the three factors are arranged in order, and the percentage values ​​decrease from front to back. The operator can quickly check and solve the fault information according to the program prompts.

[0037] 3.2. The valve core position monitoring solenoid valve 12 is closed, the system pressure is low and cannot rise to the set value. At this time, if the position monitoring of the valve core position monitoring solenoid valve 12 sends a signal, it can be determined that the valve core of the valve core position monitoring solenoid valve 12 is operating normally. Three factors can cause this situation: the first factor is damping blockage (damping a8, damping b9 and damping d11 are blocked); the second factor is the main valve core 14 stuck; the third factor is the direct-acting relief valve 13 failure.

[0038] 3.2.1. If the system detects that there is pressure in the pressure sensor C7 at the rear end of the damper A8, there is pressure in the pressure sensor A2 at the rear end of the damper B9, and there is pressure in the pressure sensor E19 at the rear end of the damper D11, the system determines through the program that the above three dampers are normal. This is the first-level judgment; the program automatically enters the second-level judgment. During the second-level judgment, the program instructs the solenoid valve E15 to close and the solenoid valve G20 to open. If the system detects that the pressure of the pressure sensor E19 at the upper end of the damper C10 is equal to the pressure of the pressure sensor D16 at the lower end, the system automatically determines that the damper C10 is normal, and the program automatically enters the third-level judgment. During the third-level judgment, the program instructs the valve core position monitoring solenoid valve 12 to be in the open and closed states. If the pressure value of the pressure sensor B6 does not change much, it can be determined that the main valve core 14 is stuck; if the pressure value of the pressure sensor B6 changes greatly, it can be determined that the direct-acting relief valve 13 is faulty, and the system program prompts the information to replace the direct-acting relief valve 13.

[0039] Flushing operation for stuck main valve core 14: the program instructs the electromagnet of solenoid valve f17 to repeatedly gain power and lose power at high frequency (i.e., repeatedly open and close) to repeatedly flush the main valve core 14; when the solenoid valve f17 is closed and the pressure value of pressure sensor b6 is close to 0, the stuck main valve core 14 is eliminated, and the stuck object of the main valve core 14 returns to the oil return filter of the oil tank through the T port, and the system automatically returns to normal operating conditions.

[0040] 3.2.2. In step 3.2.1, when the first stage determines that damping a8, damping b9 and damping d11 are blocked, the system automatically enters the backwash damping mode.

[0041] Damping A8 blocked backwashing: the program instructs the solenoid valve d5 to open and the solenoid valve e15 to close, and the damping A8 is backwashed, so that the oil flows from the left side of the damping A8 to the right side. During this period, the valve core position monitoring solenoid valve 12 is repeatedly opened and closed at a high frequency, so that a pressure step is generated on the left side of the damping A8, thereby effectively conducting the damping A8; during the flushing process, when the valve core position monitoring solenoid valve 12 is opened or closed, the pressure of the pressure sensor C7 drops, and the damping A8 is conducted. The blockage in the damping A8 returns to the oil tank return filter through the T port.

[0042] Damping b9 blocked backwashing: the program instructs the solenoid valve b3 and the solenoid valve c4 to open, and the solenoid valve e15 to close, and the damping b9 is backwashed, so that the oil flows from the upper side of the damping b9 to the lower side. During this period, the valve core position monitoring solenoid valve 12 is repeatedly opened and closed at a high frequency, so that a pressure step is generated on the upper side of the damping b9, thereby effectively conducting the damping b9. During the flushing process, when the valve core position monitoring solenoid valve 12 is opened or closed, the damping b9 is conducted when the pressure of the pressure sensor a2 drops. The blockage in the damping b9 returns to the oil tank return filter through the T port.

[0043] Damping d11 blocked backwashing: the program instructs the solenoid valve a1 and the solenoid valve g20 to open, and the solenoid valve e15 to close, and the damping d11 is backwashed, so that the oil flows from the right side of the damping d11 to the left side. During this period, the valve core position monitoring solenoid valve 12 is repeatedly opened and closed at a high frequency, so that a pressure step is generated on the right side of the damping d11, thereby effectively conducting the damping d11. During the flushing process, when the valve core position monitoring solenoid valve 12 is opened or closed, the damping d11 is conducted when the pressure of the pressure sensor e19 drops. The blockage in the damping d11 returns to the oil tank return filter through the T port.

[0044] 4. System pressure exceeds normal pressure value, pressure relief is slow, and unloading is impossible

[0045] The program detects that the system pressure exceeds the normal pressure value, the pressure relief is slow or it cannot be unloaded. If the valve core position monitoring solenoid valve 12 is normal, it is determined that the damping C10 is blocked or the main valve core 14 is stuck. If the pressure of the pressure sensor D16 is large, it is determined that the damping C10 is blocked; if the pressure of the pressure sensor D16 is almost 0, it is determined that the main valve core 14 is stuck, and the program switches to the main valve core 14 stuck flushing mode in step 3.2.1. When the damping C10 is blocked, the program automatically enters the damping C10 backwashing mode: the program instructs the solenoid valve E15 to close, the solenoid valve F17 and the solenoid valve G20 to open, and the damping C10 is backwashed, so that the oil flows from the upper side of the damping C10 to the lower side. During this period, the valve core position monitoring solenoid valve 12 is repeatedly opened and closed at a high frequency, so that a pressure step is generated on the upper side of the damping C10, thereby effectively conducting the damping C10. During the flushing process, when the valve core position monitoring solenoid valve 12 is opened or closed, the damping C10 is conducted when the pressure of the pressure sensor E19 drops. The blockage in the damper c10 returns to the oil return filter of the oil tank through the T port.

[0046] In the present invention, the main valve core 14 is detected to be stuck, the valve core position monitoring solenoid valve 12 and the direct-acting relief valve 13 are judged to be faulty, the damping blockage and the automatic backwashing are judged to be automatically operated by the system program. When the damping blockage is detected, the system automatically enters the flushing state in the safety mode until the blockage is unblocked, and then enters the normal working state; when the valve core position monitoring solenoid valve 12 or the direct-acting relief valve 13 is detected to be faulty, the system prompts to replace or handle it. Intelligent detection, judgment and automatic troubleshooting make the system greatly reduce downtime, reduce human resource labor costs, maximize equipment utilization, and greatly improve productivity.

[0047] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control oil circuit of a pilot-operated electromagnetic relief valve, characterized in that: The invention comprises a solenoid valve e (15) and a main valve core (14), wherein the inlet of the solenoid valve e (15) is connected to a P1 port for oil inlet to the system, the oil inlet of the main valve core (14) is connected to an outlet of the solenoid valve e (15), the oil outlet of the main valve core (14) is connected to a T port for oil outlet to the system through a pipeline, and the end of the main valve core (14) away from the oil inlet is connected to a valve core position monitoring solenoid valve (12) connected to the T port through a pipeline, and the valve core position monitoring solenoid valve ( A damper c (10) is arranged in a pipeline between the solenoid valve (12) and the main valve core (14); a pipeline between the valve core position monitoring solenoid valve (12) and the damper c (10) is connected to a bypass pipeline (21) and a direct-acting relief valve (13) connected to the T port; a pipeline between the solenoid valve e (15) and the main valve core (14) is connected to the bypass pipeline (21); and a damper a (8), a damper b (9) and a damper d (11) are arranged in sequence in the bypass pipeline (21); The inlet of the solenoid valve e (15) is connected to a pressure sensor b (6), the damper b (9) and the damper d (11) are connected to a pressure sensor a (2), the damper a (8) and the damper b (9) are connected to a pressure sensor c (7), the valve core position monitoring solenoid valve (12) and the damper c (10) are connected to a pressure sensor e (19), and the damper c (10) and the main valve core (14) are connected to a pressure sensor d (16).

2. The control oil circuit of a pilot-operated electromagnetic relief valve according to claim 1, characterized in that: The pressure sensor a (2) is connected to the T port through a pipeline and a solenoid valve a (1) is provided in the pipeline. The side of the pressure sensor a (2) away from the solenoid valve a (1) is connected to the P1 port through a pipeline and a solenoid valve c (4) is provided in the pipeline. The pressure sensor c (7) is connected to the T port through a pipeline and a solenoid valve b (3) is provided in the pipeline. The pressure sensor c (7) is connected to the P1 port through a pipeline and a solenoid valve d (5) is provided in the pipeline. The pressure sensor d (16) is connected to the T port through a pipeline and a solenoid valve f (17) is provided in the pipeline. The pressure sensor e (19) is connected to the P1 port through a pipeline and a solenoid valve g (20) is provided in the pipeline.

3. The control oil circuit of a pilot-operated electromagnetic relief valve according to claim 2 is characterized in that: The solenoid valve a (1), the solenoid valve b (3), the solenoid valve c (4), the solenoid valve d (5), the solenoid valve e (15), the solenoid valve f (17) and the solenoid valve g (20) are all solenoid ball valves.

4. The control oil circuit of a pilot-operated electromagnetic relief valve according to claim 1, characterized in that: The pipeline connecting the electromagnetic valve e (15) and the P1 port is connected to a connecting pipe (22) connected to the T port, and a safety valve (18) is arranged in the connecting pipe (22).

5. The control oil circuit of a pilot-operated electromagnetic relief valve according to claim 1, characterized in that: The P1 port is connected to a P2 port for delivering oil to the actuator circuit.

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