An automatic overload protection valve and a control method thereof

Abstract

An automatic overload protection valve and its control method, including oil inlet unit and two protection units, oil inlet unit includes a pressure sensor, two plug-in valves and two pressure measuring connectors, two pressure measuring connectors are connected with pressure gauges to measure the pressure of motor oil inlet and oil return port respectively, protection unit includes electromagnetic reversing valve, a overflow valve, a second overflow valve, a second pressure sensor, a first orifice and a second orifice, a pressure sensor is connected with the oil outlet of variable pump, the oil inlet of plug-in valve is connected with the oil outlet of variable pump, the oil return port of plug-in valve is connected with the oil return port of motor, the control oil port of plug-in valve is connected with the oil inlet of a overflow valve through a first orifice, the control oil port of plug-in valve is connected with the oil inlet of second pressure sensor and the oil inlet of electromagnetic reversing valve through a first orifice and a second orifice in turn, the oil outlet of electromagnetic reversing valve is connected with the oil inlet of second overflow valve. The design is not only simple operation, but also high safety.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, and in particular to an automatic overload protection valve and its control method, which is mainly applicable to simplifying operation and improving safety. Background Technology

[0002] During anchoring operations on a ship, if the anchor chain snags on an unidentified object underwater, exceeding the ship's dynamic load limit, the anchor chain must be abandoned to protect the ship's safety. In conventional ship anchor winches, this is typically handled manually by operating the winch controller to reverse the anchor release and actively abandon the anchor. In deep-sea lifting equipment operations, if the hook snags on an unidentified object such as a rock underwater, the hook cannot lift normally, and the system pressure will abnormally increase. In this situation, to protect the equipment, the system is usually unloaded manually, and the hook is actively lowered.

[0003] However, in the event of the above-mentioned emergency, it is time-consuming and labor-intensive to manually assess the underwater situation and manually operate the reversing valve or system unloading valve. In special circumstances, the best rescue time may be missed, posing a significant safety hazard. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects and problems of cumbersome operation and low safety in the existing technology, and to provide an automatic overload protection valve and its control method that are easy to operate and have high safety.

[0005] To achieve the above objectives, the technical solution of the present invention is: an automatic overload protection valve, comprising an oil inlet unit and a protection unit. The oil inlet unit includes a first pressure sensor and a cartridge valve. The protection unit includes a solenoid directional valve, a first relief valve, a second relief valve, and a second pressure sensor. The first pressure sensor is connected to the oil outlet of the variable pump. The oil inlet of the cartridge valve is connected to the oil outlet of the variable pump. The oil return port of the cartridge valve is connected to the oil return port of the motor. The control oil port of the cartridge valve is connected to the oil inlets of the first relief valve, the second pressure sensor, and the solenoid directional valve, respectively. The oil outlet of the solenoid directional valve is connected to the oil inlet of the second relief valve. The drain ports of the solenoid directional valve, the first relief valve, and the second relief valve are all connected to the oil tank.

[0006] The number of protection units is two, and the number of cartridge valves is two, with each cartridge valve connected to one of the two protection units.

[0007] The protection unit also includes a first throttle nozzle and a second throttle nozzle. The control port of the cartridge valve is connected to the inlet of the first relief valve after passing through the first throttle nozzle. The control port of the cartridge valve is connected to the inlet of the second pressure sensor after passing through the first throttle nozzle and the second throttle nozzle in sequence. The control port of the cartridge valve is connected to the inlet of the solenoid directional valve after passing through the first throttle nozzle and the second throttle nozzle in sequence.

[0008] The oil inlet unit also includes a No. 1 pressure test connector and a No. 2 pressure test connector. The No. 1 pressure test connector is connected to an external pressure gauge to measure the pressure at the motor oil inlet, and the No. 2 pressure test connector is connected to an external pressure gauge to measure the pressure at the motor oil return port.

[0009] The solenoid directional valve is a two-position three-way solenoid directional valve. When the solenoid directional valve is energized, the oil outlet of the solenoid directional valve is connected to the oil inlet of the second relief valve.

[0010] The No. 1 relief valve is used to control the maximum working pressure of the control oil circuit under normal working conditions.

[0011] The No. 2 relief valve is used to control the maximum working pressure of the control oil circuit in emergency situations.

[0012] A control method for an automatic overload protection valve, the control method comprising the following steps:

[0013] The variable pump outputs pressurized oil. Part of the pressurized oil enters the motor, and the other part of the pressurized oil enters the cartridge valve as control oil. When the pressure of the control oil entering the cartridge valve rises to overcome the spring force of the cartridge valve, the cartridge valve opens. At this time, the solenoid directional valve is de-energized. Part of the control oil enters the inlet of the first relief valve, and the other part of the control oil enters the second pressure sensor. The second pressure sensor provides feedback on the pressure of the control oil, and the pressurized oil output by the variable pump maintains the operation of the motor.

[0014] When the motor pressure continues to rise, and the pressure of the variable pump output pressure oil rises to a value greater than the set pressure value of the No. 1 relief valve, the No. 1 relief valve will start to overflow.

[0015] When the pressure difference between pressure sensor 1 and pressure sensor 2 exceeds the preset value, the electromagnet controlling the solenoid directional valve is energized, the solenoid directional valve reverses, and the control oil flows into relief valve 2 through the solenoid directional valve. The control oil overflows through relief valve 2, and at this time, the variable pump is in an unloaded state.

[0016] The set pressure value of the No. 1 relief valve is 300 bar.

[0017] The set pressure value of the No. 2 relief valve is 30 bar.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. In the automatic overload protection valve and its control method of the present invention, when the pressure difference fed back by the first pressure sensor and the second pressure sensor is greater than a preset value, the electromagnet controlling the solenoid directional valve is energized, the solenoid directional valve reverses, and the control oil flows into the second relief valve through the solenoid directional valve. The control oil overflows through the second relief valve, and at this time, the variable pump is in an unloaded state. The above design enables automatic risk identification and active unloading in emergency situations, gaining rescue time and greatly reducing safety hazards. Therefore, the present invention is simple to operate and highly safe.

[0020] 2. In the automatic overload protection valve and its control method of the present invention, there are two protection units and two cartridge valves. The two cartridge valves are connected to the two protection units respectively. By using two identical cartridge valves and protection units in parallel, the fault tolerance rate can be greatly reduced, and the reliability of the system can be further improved. Therefore, the present invention has high reliability.

[0021] 3. In the automatic overload protection valve and its control method of the present invention, the control port of the cartridge valve is connected to the inlet of the first relief valve after passing through the first throttle nozzle. The control port of the cartridge valve is then connected to the inlet of the second pressure sensor after passing through the first and second throttle nozzles in sequence. Finally, the control port of the cartridge valve is connected to the inlet of the solenoid directional valve after passing through the first and second throttle nozzles in sequence. By setting the throttle nozzles, the control oil pressure entering the protection unit can be filtered, thereby improving pressure stability. Therefore, the present invention has good stability.

[0022] 4. In the automatic overload protection valve and its control method of the present invention, the oil inlet unit further includes a first pressure testing connector and a second pressure testing connector. The first pressure testing connector is connected to an external pressure gauge to measure the pressure at the motor oil inlet, and the second pressure testing connector is connected to an external pressure gauge to measure the pressure at the motor oil return port. The pressure testing connectors and pressure sensors form redundancy, improving the reliability of the system. Therefore, the present invention has high reliability.

[0023] 5. In the automatic overload protection valve and its control method of the present invention, the first relief valve can limit the maximum working pressure of the control oil circuit under normal working conditions, and the second relief valve can limit the maximum working pressure of the control oil circuit under emergency conditions, further improving the reliability of the system. Therefore, the present invention has high reliability. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of an automatic overload protection valve according to the present invention.

[0025] Figure 2 This is a front view of the external structure of an automatic overload protection valve according to the present invention.

[0026] Figure 3 This is a top view of the external structure of an automatic overload protection valve according to the present invention.

[0027] In the diagram: Oil inlet unit 1, pressure sensor 101, cartridge valve 102, pressure test connector 103, pressure test connector 104, protection unit 2, solenoid directional valve 201, relief valve 202, relief valve 203, pressure sensor 204, throttle nozzle 205, throttle nozzle 206, variable pump 3, motor 4, oil tank 5. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] See Figures 1 to 3 An automatic overload protection valve includes an oil inlet unit 1 and a protection unit 2. The oil inlet unit 1 includes a first pressure sensor 101 and a cartridge valve 102. The protection unit 2 includes a solenoid directional valve 201, a first relief valve 202, a second relief valve 203, and a second pressure sensor 204. The first pressure sensor 101 is connected to the oil outlet of a variable pump 3. The oil inlet of the cartridge valve 102 is connected to the oil outlet of the variable pump 3. The oil return port of the cartridge valve 102 is connected to the oil return port of a motor 4. The control oil port of the cartridge valve 102 is connected to the oil inlet of the first relief valve 202, the second pressure sensor 204, and the solenoid directional valve 201, respectively. The oil outlet of the solenoid directional valve 201 is connected to the oil inlet of the second relief valve 203. The drain ports of the solenoid directional valve 201, the first relief valve 202, and the second relief valve 203 are all connected to an oil tank 5.

[0030] There are two protection units 2 and two cartridge valves 102, with each cartridge valve 102 connected to one of the two protection units 2.

[0031] The protection unit 2 also includes a first throttle nozzle 205 and a second throttle nozzle 206. The control port of the cartridge valve 102 is connected to the inlet of the first relief valve 202 after passing through the first throttle nozzle 205. The control port of the cartridge valve 102 is connected to the inlet of the second pressure sensor 204 after passing through the first throttle nozzle 205 and the second throttle nozzle 206 in sequence. The control port of the cartridge valve 102 is connected to the inlet of the solenoid directional valve 201 after passing through the first throttle nozzle 205 and the second throttle nozzle 206 in sequence.

[0032] The oil inlet unit 1 also includes a first pressure test connector 103 and a second pressure test connector 104. The first pressure test connector 103 is connected to an external pressure gauge to measure the pressure at the oil inlet of the motor 4, and the second pressure test connector 104 is connected to an external pressure gauge to measure the pressure at the oil return port of the motor 4.

[0033] The solenoid directional valve 201 is a two-position three-way solenoid directional valve. When the solenoid directional valve 201 is energized, the oil outlet of the solenoid directional valve 201 is connected to the oil inlet of the second relief valve 203.

[0034] The first relief valve 202 is used to control the maximum working pressure of the control oil circuit under normal working conditions.

[0035] The second relief valve 203 is used to control the maximum working pressure of the control oil circuit in emergency situations.

[0036] A control method for an automatic overload protection valve, the control method comprising the following steps:

[0037] The variable pump 3 outputs pressure oil. Part of the pressure oil enters the motor 4, and the other part of the pressure oil enters the cartridge valve 102 as control oil. When the pressure of the control oil entering the cartridge valve 102 rises to overcome the spring force of the cartridge valve 102, the cartridge valve 102 opens. At this time, the solenoid directional valve 201 is de-energized. Part of the control oil enters the oil inlet of the first relief valve 202, and the other part of the control oil enters the second pressure sensor 204. The second pressure sensor 204 provides feedback on the pressure of the control oil. The pressure oil output by the variable pump 3 maintains the operation of the motor 4.

[0038] When the pressure of motor 4 continues to rise, the pressure of the pressure oil output by variable pump 3 rises to a value greater than the set pressure value of relief valve 202, relief valve 202 begins to overflow.

[0039] When the pressure difference fed back by pressure sensor 101 and pressure sensor 204 is greater than the preset value, the electromagnet of the control solenoid directional valve 201 is energized, the solenoid directional valve 201 is switched, and the control oil flows into the relief valve 203 through the solenoid directional valve 201. The control oil overflows through the relief valve 203. At this time, the variable pump 3 is in the unloaded state.

[0040] The set pressure value of the first relief valve 202 is 300 bar.

[0041] The set pressure value of the second relief valve 203 is 30 bar.

[0042] The principle of this invention is explained as follows:

[0043] This design uses two identical protection units as a redundant structure. When one protection unit fails, the other protection unit can take over the function of the failed protection unit, which greatly improves the reliability of the overload protection valve in this design.

[0044] Example 1:

[0045] See Figures 1 to 3An automatic overload protection valve includes an oil inlet unit 1 and a protection unit 2. The oil inlet unit 1 includes a first pressure sensor 101 and a cartridge valve 102. The protection unit 2 includes a solenoid directional valve 201, a first relief valve 202, a second relief valve 203, and a second pressure sensor 204. The first pressure sensor 101 is connected to the oil outlet of a variable pump 3. The oil inlet of the cartridge valve 102 is connected to the oil outlet of the variable pump 3, and the oil return port of the cartridge valve 102 is connected to the oil return port of a motor 4. The control ports of the cartridge valve 102 are respectively connected to the first relief valve 202, the second pressure sensor 204, and the solenoid directional valve 204. The oil inlet of valve 01 is connected, and the oil outlet of the electromagnetic directional valve 201 is connected to the oil inlet of the second relief valve 203. The oil drain ports of the electromagnetic directional valve 201, the first relief valve 202, and the second relief valve 203 are all connected to the oil tank 5. The electromagnetic directional valve 201 is a two-position three-way electromagnetic directional valve. When the electromagnetic directional valve 201 is energized, the oil outlet of the electromagnetic directional valve 201 is connected to the oil inlet of the second relief valve 203. The first relief valve 202 is used to control the maximum working pressure of the control oil circuit under normal working conditions. The second relief valve 203 is used to control the maximum working pressure of the control oil circuit under emergency anchor release conditions. The set pressure value of the first relief valve 202 is 300 bar; the set pressure value of the second relief valve 203 is 30 bar.

[0046] According to the above scheme, a control method for an automatic overload protection valve includes the following steps:

[0047] The variable pump 3 outputs pressurized oil. Part of the pressurized oil enters the motor 4, and the other part of the pressurized oil enters the cartridge valve 102 as control oil. The initial spring force of the cartridge valve 102 is set to 0.5 bar. When the pressure of the control oil entering the cartridge valve 102 rises to overcome the spring force of the cartridge valve 102, the cartridge valve 102 opens. At this time, the solenoid directional valve 201 is de-energized. Part of the control oil enters the inlet of the first relief valve 202, and the other part of the control oil enters the second pressure sensor 204. The excess control oil enters the motor to replenish the motor. The second pressure sensor 204 provides feedback on the pressure of the control oil. The pressurized oil output by the variable pump 3 maintains the operation of the motor 4 at 300 bar.

[0048] When the pressure of motor 4 continues to rise, the pressure of the pressure oil output by variable pump 3 rises to a value greater than the set pressure value of relief valve 202, relief valve 202 begins to overflow.

[0049] When the pressure difference between pressure sensor 101 and pressure sensor 204 exceeds the preset value, it indicates an emergency. The electronic control program sends a command to the PLC to energize the electromagnet of the solenoid valve 201, causing the solenoid valve 201 to switch. Control oil flows through the solenoid valve 201 into the relief valve 203, and overflows through the relief valve 203. The pressure of the variable pump 3 output is 30 bar. At this time, the variable pump 3 is in an unloaded state, and the inlet pressure of the motor 4 is 30 bar. The motor 4 then actively releases the anchor.

[0050] Example 2:

[0051] The basic content is the same as in Example 1, except that:

[0052] There are two protection units 2 and two cartridge valves 102, with each cartridge valve 102 connected to one of the two protection units 2.

[0053] Example 3:

[0054] The basic content is the same as in Example 1, except that:

[0055] The protection unit 2 also includes a first throttle nozzle 205 and a second throttle nozzle 206. The control port of the cartridge valve 102 is connected to the inlet of the first relief valve 202 after passing through the first throttle nozzle 205. The control port of the cartridge valve 102 is connected to the inlet of the second pressure sensor 204 after passing through the first throttle nozzle 205 and the second throttle nozzle 206 in sequence. The control port of the cartridge valve 102 is connected to the inlet of the solenoid directional valve 201 after passing through the first throttle nozzle 205 and the second throttle nozzle 206 in sequence.

[0056] Example 4:

[0057] The basic content is the same as in Example 1, except that:

[0058] The oil inlet unit 1 also includes a first pressure test connector 103 and a second pressure test connector 104. The first pressure test connector 103 is connected to an external pressure gauge to measure the pressure at the oil inlet of the motor 4, and the second pressure test connector 104 is connected to an external pressure gauge to measure the pressure at the oil return port of the motor 4.

Claims

1. A control method of an automatic overload protection valve, characterized by, The automatic overload protection valve includes an oil inlet unit (1) and a protection unit (2). The oil inlet unit (1) includes a first pressure sensor (101) and a cartridge valve (102). The protection unit (2) includes a solenoid directional valve (201), a first relief valve (202), a second relief valve (203), and a second pressure sensor (204). The first pressure sensor (101) is connected to the oil outlet of the variable pump (3), and the oil inlet of the cartridge valve (102) is connected to the oil outlet of the variable pump (3). The oil ports are connected, the return port of the cartridge valve (102) is connected to the return port of the motor (4), the control oil port of the cartridge valve (102) is connected to the inlet of the first relief valve (202), the second pressure sensor (204), and the solenoid directional valve (201), respectively. The outlet of the solenoid directional valve (201) is connected to the inlet of the second relief valve (203). The drain ports of the solenoid directional valve (201), the first relief valve (202), and the second relief valve (203) are all connected to the oil tank (5). The control method includes the following steps: The variable pump (3) outputs pressure oil. Part of the pressure oil enters the motor (4), and the other part of the pressure oil enters the cartridge valve (102) as control oil. When the pressure of the control oil entering the cartridge valve (102) rises to overcome the spring force of the cartridge valve (102), the cartridge valve (102) opens. At this time, the solenoid directional valve (201) is de-energized. Part of the control oil enters the inlet of the first relief valve (202), and the other part of the control oil enters the second pressure sensor (204). The second pressure sensor (204) provides feedback on the pressure of the control oil. The pressure oil output by the variable pump (3) maintains the operation of the motor (4). When the pressure of the motor (4) continues to rise, the pressure of the pressure oil output by the variable pump (3) rises to a value greater than the set pressure value of the first relief valve (202), and the first relief valve (202) begins to overflow. When the pressure difference fed back by pressure sensor 1 (101) and pressure sensor 2 (204) is greater than the preset value, the electromagnet of the control solenoid directional valve (201) is energized, the solenoid directional valve (201) is switched, and the control oil flows into the relief valve 2 (203) through the solenoid directional valve (201). The control oil overflows through the relief valve 2 (203). At this time, the variable pump (3) is in the unloaded state.

2. The control method of an automatic overload protection valve according to claim 1, characterized in that: The number of protection units (2) is two, and the number of cartridge valves (102) is two. The two cartridge valves (102) are respectively connected to the two protection units (2).

3. A control method of an automatic overload protection valve according to claim 1 or 2, characterized in that: The protection unit (2) also includes a first throttle nozzle (205) and a second throttle nozzle (206). The control port of the cartridge valve (102) is connected to the inlet of the first relief valve (202) after passing through the first throttle nozzle (205). The control port of the cartridge valve (102) is connected to the inlet of the second pressure sensor (204) after passing through the first throttle nozzle (205) and the second throttle nozzle (206) in sequence. The control port of the cartridge valve (102) is connected to the inlet of the solenoid directional valve (201) after passing through the first throttle nozzle (205) and the second throttle nozzle (206) in sequence.

4. A control method of an automatic overload protection valve according to claim 1 or 2, characterized in that: The oil inlet unit (1) also includes a first pressure test connector (103) and a second pressure test connector (104). The first pressure test connector (103) is connected to an external pressure gauge to measure the pressure at the oil inlet of the motor (4), and the second pressure test connector (104) is connected to an external pressure gauge to measure the pressure at the oil return port of the motor (4).

5. A control method of an automatic overload protection valve according to claim 1 or 2, characterized in that: The solenoid directional valve (201) is a two-position three-way solenoid directional valve. When the solenoid directional valve (201) is energized, the oil outlet of the solenoid directional valve (201) is connected to the oil inlet of the second relief valve (203).

6. A control method of an automatic overload protection valve according to claim 1 or 2, characterized in that: The first relief valve (202) is used to control the maximum working pressure of the control oil circuit under normal working conditions.

7. A control method for an automatic overload protection valve according to claim 1 or 2, characterized in that: The second relief valve (203) is used to control the maximum working pressure of the control oil circuit in emergency situations.

8. The control method for an automatic overload protection valve according to claim 1, characterized in that: The set pressure value of the first relief valve (202) is 300 bar.

9. The control method for an automatic overload protection valve according to claim 1, characterized in that: The set pressure value of the second relief valve (203) is 30 bar.

Images