Explosion-proof linear electro-hydraulic actuator with emergency turn-off function

Abstract

The invention discloses an anti-explosion linear electro-hydraulic actuator with an emergency turn-off function. The anti-explosion linear electro-hydraulic actuator comprises an oil tank, a hydraulic control one-way valve, a hydraulic pump, an anti-explosion motor, an overflow valve, a shuttle valve, an anti-explosion pressure sensor, a pressure gauge, an anti-explosion electromagnetic valve, an energy accumulator, a hydraulic lock, a hydraulic oil cylinder, an anti-explosion displacement sensor, a manual pump, a manual reversing valve and a one-way valve. The hydraulic system adopts a closed loop, oil is supplemented for flow deviation caused by an asymmetric cylinder through a hydraulic control one-way valve, stretching and retracting of an oil cylinder are achieved by controlling the rotating direction of a motor, a reversing valve does not need to be installed for high-pressure and low-pressure oil way switching, the number of electromagnetic control valves is small, the structure is simple, and control is convenient. An energy accumulator oil supply mode is adopted to quickly reset the actuator in a power-off state, a reset spring is not needed, and a manual pump can supplement pressure to the energy accumulator and can manually reset the actuator. A displacement sensor is installed on the oil cylinder for position feedback, and accurate position control of the oil cylinder can be achieved by adjusting the rotating speed of the motor.

Description

Technical Field

[0001] The invention relates to the field of industrial valve actuators, and in particular to an explosion-proof linear electro-hydraulic actuator with an emergency shut-off function. Background Art

[0002] The linear electric actuators for industrial valves have relatively low reliability, relatively low adjustment accuracy, long action time, and cannot be closed in emergency situations such as fire and power outages, so their scope of use is also limited. Electro-hydraulic actuators are widely used due to their large output force, stable operation, and high adjustment accuracy, but there are also many problems with electro-hydraulic actuators on the market, which limits the scope of use of electro-hydraulic actuators.

[0003] Most of the electro-hydraulic actuators on the market currently do not have an emergency shutdown function, or use a manual pump for emergency shutdown, or use a spring for emergency shutdown. Electro-hydraulic actuators without an emergency shutdown function cannot be shut down in emergency situations such as fire and power outages, which can easily cause accidents. Electro-hydraulic actuators that use a manual pump for emergency shutdown have a slow shutdown time and cannot meet the needs of rapid shutdown in emergency situations such as fire and power outages. Electro-hydraulic actuators that use spring emergency shutdowns cannot meet the market's demand for miniaturization and diversification of electro-hydraulic actuators due to their large size and fixed installation method. Therefore, the market is in urgent need of a simple way to achieve the emergency shutdown function of electro-hydraulic actuators.

[0004] Linear electro-hydraulic actuators mostly use reversing valve switching to control the extension and retraction of the actuator. In explosion-proof scenarios, explosion-proof solenoid valves are required, which increases the weight and volume of the electro-hydraulic actuator, increases the number of explosion-proof electrical components and control ports, and reduces the reliability of the electro-hydraulic actuator. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an explosion-proof linear electro-hydraulic actuator with an emergency shutdown function, which has the characteristics of high safety, high reliability and high cost performance.

[0006] The technical solution adopted by the present invention is as follows:

[0007] An explosion-proof linear electro-hydraulic actuator with an emergency shutdown function, comprising an oil tank, a hydraulically controlled one-way valve 1, a hydraulically controlled one-way valve 2, a hydraulic pump, an explosion-proof motor, a relief valve 1, a relief valve 2, a shuttle valve, an explosion-proof pressure sensor 1, an explosion-proof pressure sensor 2, a pressure gauge, an explosion-proof solenoid valve, an accumulator, a two-way hydraulic lock, a hydraulic cylinder, an explosion-proof displacement sensor, a manual pump, a manual reversing valve and a one-way valve;

[0008] The explosion-proof motor drives the hydraulic pump, which is a bidirectional hydraulic pump, including a left oil port and a right oil port, and realizes oil discharge on the left side and oil suction or oil return on the right side when the explosion-proof motor is driven forward and reversely, or oil discharge on the right side and oil suction or oil return on the left side;

[0009] The two oil ports of the hydraulically controlled one-way valve 1 are respectively connected to the right oil port of the hydraulic pump and the oil tank, and the control port of the hydraulically controlled one-way valve 1 is connected to the left oil port of the hydraulic pump; the two oil ports of the hydraulically controlled one-way valve 2 are connected to the left oil port of the hydraulic pump and the oil tank, and the control port of the hydraulically controlled one-way valve 2 is connected to the right oil port of the hydraulic pump, so as to realize the oil tank replenishing oil to the oil ports on both sides of the hydraulic pump;

[0010] The inlet of the relief valve 1 is connected to the left oil port of the hydraulic pump, and the outlet of the relief valve 1 is connected to the oil tank, so as to limit the large chamber circuit pressure of the hydraulic cylinder; the inlet of the relief valve 2 is connected to the right oil port of the hydraulic pump, and the outlet of the relief valve 2 is connected to the oil tank, so as to limit the small chamber circuit pressure of the hydraulic cylinder;

[0011] The two inlets of the shuttle valve are respectively connected to the oil ports on both sides of the hydraulic pump to lead out the high pressure on both sides of the hydraulic pump, and the outlet of the shuttle valve is connected to the explosion-proof pressure sensor 1 and the pressure gauge to feedback and display the system pressure;

[0012] The explosion-proof solenoid valve is a two-position, two-way reversing valve, and the two ports are respectively connected to the left oil port of the hydraulic pump and the oil port of the accumulator. When the power is off, the oil port of the accumulator is connected to the left oil port of the hydraulic pump, and when the power is on, the oil port of the accumulator is cut off and disconnected from the left oil port of the hydraulic pump.

[0013] The oil port of the accumulator is also connected to the second explosion-proof pressure sensor;

[0014] The bidirectional hydraulic lock is connected to the oil ports on both sides of the hydraulic pump and the two chambers of the hydraulic cylinder to achieve position locking of the hydraulic cylinder;

[0015] The hydraulic cylinder is a single-rod asymmetric piston cylinder, on which the explosion-proof displacement sensor is installed to provide real-time feedback on the cylinder position and achieve precise position control of the cylinder;

[0016] The oil suction port of the manual pump is connected to the oil tank, and the oil outlet is connected to the P port of the manual reversing valve;

[0017] The manual reversing valve is a two-position four-way reversing valve, the T port is disconnected and not connected to the oil circuit, the A port is connected to the forward oil port of the one-way valve, the B port is connected to the left oil port of the hydraulic pump and the lower oil port of the explosion-proof solenoid valve, and the P port of the reversing valve is connected to the A port, and the B port is disconnected from the T port when the reversing valve is in the right position (reset) state. When switched to the left position, the P port is connected to the B port, and the A port is connected to the T port.

[0018] The reverse oil port of the one-way valve is connected to the oil port of the accumulator.

[0019] Furthermore, the explosion-proof motor is a servo motor or a speed-regulating motor with a brake, and has forward and reverse rotation and variable speed functions; the oil tank is a rectangular closed oil tank.

[0020] Furthermore, the relief valve 1 and the relief valve 2 are both plug-in manually adjustable relief valves; the accumulator is a diaphragm accumulator that can be repeatedly filled with oil and discharged with oil.

[0021] Furthermore, the manual control process of the oil circuit when the accumulator is in the oil-filled state is as follows: the explosion-proof solenoid valve is energized, the manual pump is manually pressed to discharge the high-pressure oil, the manual reversing valve is kept in the right position, and the high-pressure oil enters the accumulator through the manual reversing valve and the one-way valve. After the explosion-proof pressure sensor 2 monitors that the accumulator has reached the set pressure, the charging is completed, and the manual pump is stopped from being pressed.

[0022] Furthermore, the automatic control process of the oil circuit under the retraction action of the piston rod of the hydraulic cylinder is as follows: the explosion-proof motor rotates counterclockwise, the right side of the hydraulic pump is the high-pressure oil discharge port, the oil enters the small chamber of the hydraulic cylinder through the right-side one-way valve in the two-way hydraulic lock, and at the same time, the high-pressure oil enters the left control chamber of the two-way hydraulic lock, opening the left-side one-way valve of the two-way hydraulic lock, and the large chamber circuit of the hydraulic cylinder is connected, the high-pressure oil pushes the piston rod to retract, and the low-pressure oil in the large chamber of the oil cylinder enters the left oil port of the hydraulic pump. Since the hydraulic cylinder is a single-rod asymmetric piston cylinder, the low-pressure oil discharged from the large chamber is more than the oil inlet of the small chamber, and the high-pressure oil on the right side of the hydraulic pump has opened the hydraulic control one-way valve 2, and the excess large chamber return oil returns to the oil tank through the hydraulic control one-way valve 2; when the pressure of the high-pressure circuit on the right side reaches the pressure set by the overflow valve 2, a part of the high-pressure oil on the right side overflows and returns the oil through the overflow valve 2.

[0023] Furthermore, the automatic control process of the oil circuit when the piston rod of the hydraulic cylinder is retracted into position is as follows: the explosion-proof motor continues to rotate counterclockwise, and since the hydraulic cylinder has been retracted into position, the high-pressure oil no longer enters the small cylinder chamber of the hydraulic cylinder, and directly overflows and returns the oil through the overflow valve 2; no return oil is discharged from the large cylinder chamber of the hydraulic cylinder, and the left oil port of the hydraulic pump draws oil from the oil tank through the hydraulically controlled one-way valve 2.

[0024] Furthermore, the automatic control process of the oil circuit under the extension action of the piston rod of the hydraulic cylinder is as follows: the explosion-proof motor rotates clockwise, the left side of the hydraulic pump is the high-pressure oil discharge port, the oil enters the large chamber of the hydraulic cylinder through the left one-way valve in the two-way hydraulic lock, and at the same time, the high-pressure oil enters the right control chamber of the two-way hydraulic lock, opens the right one-way valve of the two-way hydraulic lock, and the small chamber circuit of the hydraulic cylinder is connected, the high-pressure oil pushes the piston rod to extend, and the low-pressure oil in the small chamber of the hydraulic cylinder enters the right oil port of the hydraulic pump. Since the hydraulic cylinder is a single-rod asymmetric piston cylinder, the low-pressure oil discharged from the small chamber is less than the oil inlet of the large chamber, and the oil tank replenishes oil to the right suction port of the hydraulic pump through the hydraulic control one-way valve; when the pressure of the left high-pressure circuit reaches the set pressure of the overflow valve, a part of the left high-pressure oil overflows back through the overflow valve.

[0025] Furthermore, the automatic control process of the oil circuit when the piston rod of the hydraulic cylinder is in the extended position is as follows: the explosion-proof motor continues to rotate clockwise, and since the hydraulic cylinder has been extended into place, the high-pressure oil no longer enters the large cylinder chamber of the hydraulic cylinder, and directly overflows and returns the oil through the overflow valve 1; there is no return oil discharged from the small cylinder chamber of the hydraulic cylinder, and the right oil port of the hydraulic pump draws oil from the oil tank through the hydraulically controlled one-way valve 1.

[0026] Furthermore, the automatic control process of the oil circuit when the actuator loses power due to an emergency is as follows: the explosion-proof motor is powered off and the brake is engaged, the hydraulic pump stops and is locked, the explosion-proof solenoid valve is powered off and is in the normally open position, and the high-pressure oil in the accumulator enters the large chamber of the hydraulic cylinder through the left-side one-way valve of the two-way hydraulic lock. At the same time, the high-pressure oil enters the right-side control chamber of the two-way hydraulic lock, opens the right-side one-way valve of the two-way hydraulic lock, and the small chamber circuit of the hydraulic cylinder is connected, and the high-pressure oil pushes the piston rod to extend quickly, closing the actuator urgently; the high-pressure oil in the accumulator has opened the hydraulically controlled one-way valve, and the return oil from the small chamber of the cylinder returns to the oil tank through the hydraulically controlled one-way valve.

[0027] Furthermore, when the actuator loses power suddenly and the accumulator loses pressure, the manual control process of the oil circuit is as follows: the explosion-proof motor is powered off and the brake is engaged, the hydraulic pump stops and is locked, the explosion-proof solenoid valve is powered off and is in the normally open position, the manual reversing valve is manually switched to the left position, and the manual pump is manually pressed to discharge high-pressure oil. The high-pressure oil enters the large chamber of the hydraulic cylinder through the P port and B port of the manual reversing valve and the left-side one-way valve of the two-way hydraulic lock. At the same time, the high-pressure oil enters the right-side control chamber of the two-way hydraulic lock, opens the right-side one-way valve of the two-way hydraulic lock, and the small-chamber circuit of the hydraulic cylinder is connected, and the high-pressure oil pushes the piston rod to extend, manually closing the actuator; the high-pressure oil discharged by the manual pump has opened the hydraulically controlled one-way valve, and the return oil from the small chamber of the cylinder returns to the oil tank through the hydraulically controlled one-way valve.

[0028] The beneficial effects of the present invention are as follows:

[0029] 1. The present invention realizes the extension and retraction of the oil cylinder by controlling the rotation direction of the motor. There is no need to install a reversing valve to switch the high and low pressure oil circuits. The number of electromagnetic control valves is small, the structure is simple, and the control is convenient.

[0030] 2. The present invention uses an accumulator to supply oil to quickly reset the actuator in a power-off state, without the need to install a reset spring.

[0031] 3. A displacement sensor is installed on the oil cylinder of the present invention for position feedback, and accurate position control of the oil cylinder can be achieved by adjusting the motor speed.

[0032] 4. The present invention adopts a hydraulically controlled one-way valve to replenish oil to solve the problem of less oil return in the small cavity of the asymmetric cylinder in the closed loop. The cylinder is a single-rod cylinder and the actuator is relatively small in size.

[0033] 5. The present invention adopts a manual pump to charge the accumulator, and the automatic control circuit of the actuator is not affected during the charging process. The actuator can also be manually reset when the accumulator loses pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the hydraulic principle of the present invention.

[0035] Figure 2 It is a schematic diagram of the oil circuit of the accumulator of the present invention when it is in the oil-filled state.

[0036] Figure 3 It is a schematic diagram of the oil circuit under the retracting action of the piston rod of the hydraulic oil cylinder of the present invention.

[0037] Figure 4 It is a schematic diagram of the oil circuit when the piston rod of the hydraulic oil cylinder of the present invention is retracted into position.

[0038] Figure 5 It is a schematic diagram of the oil circuit under the extension action of the piston rod of the hydraulic oil cylinder of the present invention.

[0039] Figure 6 It is a schematic diagram of the oil circuit when the piston rod of the hydraulic oil cylinder of the present invention is in a state of being fully extended.

[0040] Figure 7 It is a schematic diagram of the oil circuit when the actuator is in a fast closing state when the power is off in the present invention.

[0041] Figure 8 It is a schematic diagram of the oil circuit when the actuator is manually closed in the event of a power outage of the present invention.

[0042] In the figure, 1 is an oil tank, 2-1 is a hydraulically controlled one-way valve 1, 2-2 is a hydraulically controlled one-way valve 2, 3 is a hydraulic pump, 4 is an explosion-proof motor, 5-1 is an overflow valve 1, 5-2 is an overflow valve 2, 6 is a shuttle valve, 7-1 is an explosion-proof pressure sensor 1, 7-2 is an explosion-proof pressure sensor 2, 8 is a pressure gauge, 9 is an explosion-proof solenoid valve, 10 is an accumulator, 11 is a hydraulic lock, 12 is a hydraulic cylinder, 13 is an explosion-proof displacement sensor, 14 is a manual pump, 15 is a manual reversing valve, and 16 is a one-way valve. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] like Figure 1 As shown, it includes an oil tank 1, a hydraulically controlled one-way valve 2-1, a hydraulically controlled one-way valve 2-2, a hydraulic pump 3, an explosion-proof motor 4, an overflow valve 5-1, an overflow valve 5-2, a shuttle valve 6, an explosion-proof pressure sensor 7-1, an explosion-proof pressure sensor 7-2, a pressure gauge 8, an explosion-proof solenoid valve 9, an accumulator 10, a hydraulic lock 11, a hydraulic cylinder 12, an explosion-proof displacement sensor 13, a manual pump 14, a manual reversing valve 15, and a one-way valve 16.

[0045] The hydraulic pump 3 is a bidirectional hydraulic pump with oil ports on the left and right sides. When the explosion-proof motor 4 rotates clockwise, the left oil port is a high-pressure oil outlet, and the right oil port is an oil suction port and an oil return port; when the explosion-proof motor 4 rotates counterclockwise, the right oil port is a high-pressure oil outlet, and the left oil port is an oil suction port and an oil return port. The two oil ports of the hydraulic control check valve 1 2-1 are respectively connected to the right oil port of the hydraulic pump 3 and the oil tank 1, and the control port of the hydraulic control check valve 1 2-1 is connected to the left oil port of the hydraulic pump 3; the two oil ports of the hydraulic control check valve 2 2-2 are connected to the left oil port of the hydraulic pump 3 and the oil tank 1, and the control port of the hydraulic control check valve 2 2-2 is connected to the right oil port of the hydraulic pump 3. When the right oil port of the hydraulic pump 3 is an oil suction port, oil can be replenished through the hydraulic control check valve 1 2-1, and the hydraulic control check valve 2 2-2 can block the left high-pressure port from returning oil to the oil tank 1. When the left circuit of the hydraulic cylinder 12 is under high pressure, the right circuit of the hydraulic cylinder 12 can return oil through the hydraulically controlled one-way valve 2-1.

[0046] The relief valve 1 5-1 and the relief valve 2 5-2 are both plug-in manually adjustable relief valves, wherein the inlet of the relief valve 1 5-1 is connected to the left oil port of the hydraulic pump 3, and the outlet is connected to the oil tank 1, which is used to control the circuit pressure of the large cavity of the hydraulic cylinder 12 and the left oil port of the hydraulic pump 3; the inlet of the relief valve 2 5-2 is connected to the right oil port of the hydraulic pump 3, and the outlet is connected to the oil tank 1, which is used to limit the circuit pressure of the small cavity of the hydraulic cylinder 12 and the right oil port of the hydraulic pump 3. When the relief valve 1 5-1 and the relief valve 2 5-2 are set to a higher pressure, they can also be used as safety valves.

[0047] The two inlets of the shuttle valve 6 are respectively connected to the oil ports on both sides of the hydraulic pump 3, leading out the high pressure on both sides of the hydraulic pump 3, and connected to the explosion-proof pressure sensor 7-1 and the pressure gauge 8 to feedback and display the system pressure.

[0048] The accumulator 10 is a diaphragm accumulator, which can be repeatedly filled and drained, and the filling pressure is set by the relief valve 5-1.

[0049] The explosion-proof pressure sensor 7 - 2 is installed at the outlet of the accumulator 10 to measure and feedback the pressure of the accumulator 10 .

[0050] The explosion-proof solenoid valve 9 is a two-position, two-way reversing valve, and its two ports are respectively connected to the left oil port of the hydraulic pump 3 and the oil port of the accumulator 10. When the power is off, the oil port of the accumulator 10 is connected to the left oil port of the hydraulic pump 3, and when the power is on, the oil port of the accumulator 10 is cut off and disconnected from the left oil port of the hydraulic pump 3.

[0051] The hydraulic lock 11 is a bidirectional hydraulic lock, which can lock the position of the hydraulic cylinder 12 in two directions.

[0052] The hydraulic cylinder 12 is a single-rod asymmetric piston cylinder, and is equipped with an explosion-proof displacement sensor 13, which can provide real-time feedback on the cylinder position and achieve precise position control of the cylinder.

[0053] The oil suction port of the manual pump 14 is connected to the oil tank 1 , and the oil outlet is connected to the P port of the manual reversing valve 15 .

[0054] The manual reversing valve 15 is a two-position four-way reversing valve. The T port is disconnected and not connected to the oil circuit, the A port is connected to the forward oil port of the one-way valve 16, and the B port is connected to the left oil port of the hydraulic pump 3 and the lower oil port of the explosion-proof solenoid valve 9. When the reversing valve is in the right position (reset), the P port is connected to the A port, and the B port is disconnected from the T port. When switched to the left position, the P port is connected to the B port, and the A port is connected to the T port.

[0055] The reverse oil port of the one-way valve 16 is connected to the oil port of the accumulator 10 , so that the high-pressure oil at port A of the manual reversing valve 15 can flow in one direction to the oil port of the accumulator 10 .

[0056] The oil tank 1 is a rectangular closed oil tank, and the oil tanks shown in the figure are all the same oil tank.

[0057] The oil circuit diagram of the explosion-proof linear electro-hydraulic actuator with emergency shutdown function provided by the embodiment of the present invention in the state where the accumulator is filled with oil is as follows: Figure 2 As shown: the explosion-proof solenoid valve 9 is energized, the manual pump 14 is manually pressed to discharge the high-pressure oil, the manual reversing valve 15 is kept in the right position, and the high-pressure oil enters the accumulator 10 through the manual reversing valve 15 and the one-way valve 16. The explosion-proof pressure sensor 2 7-2 detects that the accumulator 10 reaches the pressure and the charging is completed, and the manual pump 14 is stopped. When the above charging operation is performed, the automatic control process of the electro-hydraulic actuator is not affected.

[0058] The oil circuit diagram of the explosion-proof linear electro-hydraulic actuator with emergency shutdown function provided by the embodiment of the present invention when the piston rod is retracted is as follows: Figure 3 As shown: the explosion-proof motor 4 rotates counterclockwise, the right side of the hydraulic pump 3 is the high-pressure oil discharge port, the oil enters the small chamber of the hydraulic cylinder 12 through the right-side check valve in the two-way hydraulic lock 11, and the high-pressure oil enters the left control chamber of the two-way hydraulic lock 11 at the same time, the check valve on the left side of the hydraulic lock 11 is opened, the large chamber circuit of the hydraulic cylinder 12 is connected, the high-pressure oil pushes the piston rod to retract, and the low-pressure oil in the large chamber of the cylinder enters the left suction port of the hydraulic pump 3. Since the hydraulic cylinder 12 is an asymmetric cylinder, the low-pressure oil discharged from the large chamber is more than the oil intake of the small chamber. The high-pressure oil on the right side of the hydraulic pump 3 has opened the hydraulic control check valve 2-2, and the excess large chamber return oil can be returned to the oil tank 1 through the hydraulic control check valve 2-2. When the pressure of the high-pressure circuit on the right side reaches the pressure set by the overflow valve 2 5-2, part of the high-pressure oil on the right side overflows and returns through the overflow valve 2 5-2.

[0059] The oil circuit diagram of the explosion-proof linear electro-hydraulic actuator with emergency shutdown function provided by the embodiment of the present invention when the piston rod of the hydraulic cylinder is retracted into position is as follows: Figure 4 As shown: the explosion-proof motor 4 rotates counterclockwise, the right side of the hydraulic pump 3 is the high-pressure oil discharge port, and since the hydraulic cylinder 11 has retracted into place, the high-pressure oil no longer enters the small chamber of the cylinder, and directly overflows and returns the oil through the overflow valve 2 5-2. The system pressure is the set pressure of the overflow valve 2 5-2, and there is no return oil discharged from the large chamber of the cylinder. The left suction port of the hydraulic pump 3 draws oil from the oil tank 1 through the hydraulically controlled one-way valve 2-2.

[0060] The oil circuit diagram of the explosion-proof linear electro-hydraulic actuator with emergency shutdown function provided by the embodiment of the present invention when the piston rod is extended is as follows: Figure 5As shown: the explosion-proof motor 4 rotates clockwise, the left side of the hydraulic pump 3 is the high-pressure oil discharge port, the oil enters the large chamber of the hydraulic cylinder 12 through the left one-way valve in the two-way hydraulic lock 11, and the high-pressure oil enters the right control chamber of the two-way hydraulic lock 11 at the same time, the one-way valve on the right side of the hydraulic lock 11 is opened, the small chamber circuit of the hydraulic cylinder is connected, the high-pressure oil pushes the piston rod to extend, and the low-pressure oil in the small chamber of the cylinder enters the right suction port of the hydraulic pump 3. Since the hydraulic cylinder 12 is an asymmetric cylinder, the low-pressure oil discharged from the small chamber is less than the oil inlet of the large chamber, and the oil tank 1 can replenish oil to the right suction port of the hydraulic pump 3 through the hydraulic control one-way valve 2-1. When the pressure of the left high-pressure circuit reaches the pressure set by the overflow valve 5-1, part of the left high-pressure oil overflows back through the overflow valve 5-1.

[0061] The oil circuit diagram of the explosion-proof linear electro-hydraulic actuator with emergency shutdown function provided by the embodiment of the present invention when the piston rod of the hydraulic cylinder is extended to the full position is as follows: Figure 6 As shown: the explosion-proof motor 4 rotates clockwise, the left side of the hydraulic pump 3 is the high-pressure oil discharge port, and because the hydraulic cylinder 11 has been extended into place, the high-pressure oil no longer enters the large chamber of the cylinder, and directly overflows and returns the oil through the relief valve 5-1. The system pressure is the set pressure of the relief valve 5-1, and there is no return oil discharged from the small chamber of the cylinder. The right side oil suction port of the hydraulic pump 3 sucks oil from the oil tank 1 through the hydraulically controlled one-way valve 2-1.

[0062] The oil circuit diagram of the explosion-proof linear electro-hydraulic actuator with emergency shutdown function provided by the embodiment of the present invention in the actuator fast closing state is as follows: Figure 7 As shown: when the actuator loses power suddenly, the explosion-proof motor 4 is powered off and the brake is engaged, the hydraulic pump 3 stops and locks, the explosion-proof solenoid valve 9 is powered off and is in the normally open position, and the high-pressure oil in the accumulator 10 enters the large chamber of the hydraulic cylinder 12 through the left one-way valve in the two-way hydraulic lock 11. At the same time, the high-pressure oil enters the right control chamber of the two-way hydraulic lock 11, opens the one-way valve on the right side of the hydraulic lock 11, and the small chamber circuit of the hydraulic cylinder is connected. The high-pressure oil pushes the piston rod to extend quickly, and the actuator is urgently closed. The high-pressure oil at the outlet of the accumulator 10 has opened the hydraulically controlled one-way valve 2-1, and the return oil from the small chamber of the cylinder can return to the oil tank 1 through the hydraulically controlled one-way valve 2-1.

[0063] The oil circuit diagram of the explosion-proof linear electro-hydraulic actuator with emergency shutdown function provided by the embodiment of the present invention in the manual closing state is as follows Figure 8As shown: when the actuator loses power suddenly and the accumulator 10 loses pressure, the explosion-proof motor 4 is powered off and braked, the hydraulic pump 3 stops and locks, the explosion-proof solenoid valve 9 is powered off and in the normally open position, the manual reversing valve 15 is manually switched to the left position, and the manual pump 14 is manually pressed to discharge the high-pressure oil. The high-pressure oil enters the large chamber of the hydraulic cylinder 12 through the P port and the B port of the manual reversing valve 15 and the left one-way valve of the two-way hydraulic lock 11, and at the same time, the high-pressure oil enters the right control chamber of the two-way hydraulic lock 11. The right one-way valve of the two-way hydraulic lock 11 and the small chamber circuit of the hydraulic cylinder 12 are connected, and the high-pressure oil pushes the piston rod to extend, and the actuator is manually closed. The high-pressure oil discharged by the manual pump 14 has opened the hydraulic control one-way valve 2-1, and the oil return from the small chamber of the oil cylinder returns to the oil tank 1 through the hydraulic control one-way valve 2-1. Except when the manual pump 14 is used to manually close the actuator, the manual reversing valve 15 is kept in the right position.

[0064] The present invention is mainly used in the technical field of industrial valve actuators. It is an explosion-proof linear electro-hydraulic actuator with an emergency shutdown function. The direction of the actuator can be controlled by motor reversing. The control is simple, and there is no need to install a large number of electromagnetic reversing valves. It also has an emergency shutdown function and has important engineering significance.

[0065] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. An explosion-proof linear electro-hydraulic actuator with emergency shutdown function, characterized in that: It comprises an oil tank (1), a hydraulically controlled one-way valve 1 (2-1), a hydraulically controlled one-way valve 2 (2-2), a hydraulic pump (3), an explosion-proof motor (4), a relief valve 1 (5-1), a relief valve 2 (5-2), a shuttle valve (6), an explosion-proof pressure sensor 1 (7-1), an explosion-proof pressure sensor 2 (7-2), a pressure gauge (8), an explosion-proof solenoid valve (9), an accumulator (10), a two-way hydraulic lock (11), a hydraulic cylinder (12), an explosion-proof displacement sensor (13), a manual pump (14), a manual reversing valve (15) and a one-way valve (16); The explosion-proof motor (4) drives the hydraulic pump (3), and the hydraulic pump (3) is a bidirectional hydraulic pump, including a left oil port and a right oil port, and when the explosion-proof motor (4) is driven forward or reversely, oil is discharged from the left side and oil is sucked or returned from the right side, or oil is discharged from the right side and oil is sucked or returned from the left side; The two oil ports of the hydraulically controlled one-way valve (2-1) are respectively connected to the right oil port of the hydraulic pump (3) and the oil tank (1), and the control port of the hydraulically controlled one-way valve (2-1) is connected to the left oil port of the hydraulic pump (3); the two oil ports of the hydraulically controlled one-way valve (2-2) are connected to the left oil port of the hydraulic pump (3) and the oil tank (1), and the control port of the hydraulically controlled one-way valve (2-2) is connected to the right oil port of the hydraulic pump (3), so as to realize the oil tank (1) replenishing oil to the oil ports on both sides of the hydraulic pump (3); The inlet of the overflow valve 1 (5-1) is connected to the left oil port of the hydraulic pump (3), and the outlet of the overflow valve 1 (5-1) is connected to the oil tank (1), so as to limit the large chamber circuit pressure of the hydraulic cylinder (12); the inlet of the overflow valve 2 (5-2) is connected to the right oil port of the hydraulic pump (3), and the outlet of the overflow valve 2 (5-2) is connected to the oil tank (1), so as to limit the small chamber circuit pressure of the hydraulic cylinder (12); The two inlets of the shuttle valve (6) are respectively connected to the oil ports on both sides of the hydraulic pump (3) to lead out the high pressure on both sides of the hydraulic pump (3); the outlet of the shuttle valve (6) is connected to the explosion-proof pressure sensor 1 (7-1) and the pressure gauge (8) to feedback and display the system pressure; The explosion-proof solenoid valve (9) is a two-position, two-way reversing valve, the two ports of which are respectively connected to the left oil port of the hydraulic pump (3) and the oil port of the accumulator (10). When the power is off, the oil port of the accumulator (10) is connected to the left oil port of the hydraulic pump (3); when the power is on, the oil port of the accumulator (10) is cut off from the left oil port of the hydraulic pump (3). The oil port of the accumulator (10) is also connected to the second explosion-proof pressure sensor (7-2); The bidirectional hydraulic lock (11) is connected to the oil ports on both sides of the hydraulic pump (3) and the two chambers of the hydraulic cylinder (12) to achieve position locking of the hydraulic cylinder (12); The hydraulic cylinder (12) is a single-rod asymmetric piston cylinder, on which the explosion-proof displacement sensor (13) is installed for providing real-time feedback on the cylinder position to achieve precise position control of the cylinder; The oil suction port of the manual pump (14) is connected to the oil tank (1), and the oil outlet is connected to the P port of the manual reversing valve (15); The manual reversing valve (15) is a two-position four-way reversing valve, the T port is disconnected and not connected to the oil circuit, the A port is connected to the forward oil port of the one-way valve (16), and the B port is connected to the left oil port of the hydraulic pump (3) and the lower oil port of the explosion-proof solenoid valve (9). When the reversing valve is in the right position (reset), the P port is connected to the A port, and the B port is disconnected from the T port. When the reversing valve is switched to the left position, the P port is connected to the B port, and the A port is connected to the T port. The reverse oil port of the one-way valve (16) is connected to the oil port of the accumulator (10).

2. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 1, characterized in that: The explosion-proof motor (4) is a servo motor or a speed-regulating motor with a brake, and has forward and reverse rotation and speed-changing functions; the oil tank (1) is a rectangular closed oil tank.

3. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 1, characterized in that: The overflow valve 1 (5-1) and the overflow valve 2 (5-2) are both plug-in manually adjustable overflow valves; the accumulator (10) is a diaphragm accumulator that can be repeatedly filled with oil and discharged with oil.

4. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 1, characterized in that: The manual control process of the oil circuit when the accumulator (10) is in the oil-filled state is as follows: the explosion-proof solenoid valve (9) is energized, the manual pump (14) is manually pressed to discharge the high-pressure oil, the manual reversing valve (15) is kept in the right position, the high-pressure oil enters the accumulator (10) through the manual reversing valve (15) and the one-way valve (16), and the explosion-proof pressure sensor 2 (7-2) monitors that the accumulator (10) reaches the set pressure, and the charging is completed, and the manual pump (14) is stopped from being pressed.

5. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 4, characterized in that: The automatic control process of the oil circuit under the retraction action of the piston rod of the hydraulic oil cylinder (12) is as follows: the explosion-proof motor (4) rotates counterclockwise, the right side of the hydraulic pump (3) is a high-pressure oil discharge port, the oil enters the small chamber of the hydraulic oil cylinder (12) through the right-side one-way valve in the two-way hydraulic lock (11), and at the same time, the high-pressure oil enters the left-side control chamber of the two-way hydraulic lock (11), the left-side one-way valve of the two-way hydraulic lock (11) is opened, the large chamber circuit of the hydraulic oil cylinder (12) is connected, the high-pressure oil pushes the piston rod to retract, and the large chamber of the oil cylinder is opened. The low-pressure oil enters the left oil port of the hydraulic pump (3). Since the hydraulic oil cylinder (12) is a single-rod asymmetric piston cylinder, the low-pressure oil discharged from the large chamber is greater than the oil intake of the small chamber. The high-pressure oil on the right side of the hydraulic pump (3) has opened the hydraulically controlled one-way valve (2-2). The excess return oil from the large chamber returns to the oil tank (1) through the hydraulically controlled one-way valve (2-2). When the pressure of the high-pressure circuit on the right side reaches the pressure set by the overflow valve (5-2), a part of the high-pressure oil on the right side overflows and returns through the overflow valve (5-2).

6. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 5, characterized in that: The automatic control process of the oil circuit when the piston rod of the hydraulic oil cylinder (12) is retracted into position is as follows: the explosion-proof motor (4) continues to rotate counterclockwise, and since the hydraulic oil cylinder (12) has been retracted into position, the high-pressure oil no longer enters the small cylinder chamber of the hydraulic oil cylinder (12), and directly overflows and returns the oil through the second overflow valve (5-2); no return oil is discharged from the large cylinder chamber of the hydraulic oil cylinder (12), and the left oil port of the hydraulic pump (3) draws oil from the oil tank (1) through the second hydraulic control check valve (2-2).

7. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 6, characterized in that: The automatic control process of the oil circuit under the extension action of the piston rod of the hydraulic oil cylinder (12) is as follows: the explosion-proof motor (4) rotates clockwise, the left side of the hydraulic pump (3) is a high-pressure oil discharge port, the oil enters the large chamber of the hydraulic oil cylinder (12) through the left one-way valve in the two-way hydraulic lock (11), and at the same time, the high-pressure oil enters the right control chamber of the two-way hydraulic lock (11), the right one-way valve of the two-way hydraulic lock (11) is opened, the small chamber circuit of the hydraulic oil cylinder (12) is connected, and the high-pressure oil pushes The piston rod extends, and the low-pressure oil in the small chamber of the hydraulic cylinder (12) enters the right oil port of the hydraulic pump (3). Since the hydraulic cylinder (12) is a single-rod asymmetric piston cylinder, the low-pressure oil discharged from the small chamber is less than the oil inlet of the large chamber. The oil tank (1) replenishes oil to the right oil suction port of the hydraulic pump (3) through the hydraulically controlled one-way valve (2-1). When the pressure of the left high-pressure circuit reaches the set pressure of the overflow valve (5-1), a part of the left high-pressure oil overflows back through the overflow valve (5-1).

8. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 7, characterized in that: The automatic control process of the oil circuit when the piston rod of the hydraulic oil cylinder (12) is in the state of being extended to the full position is as follows: the explosion-proof motor (4) continues to rotate clockwise, and since the hydraulic oil cylinder (12) has been extended to the full position, the high-pressure oil no longer enters the large cylinder chamber of the hydraulic oil cylinder (12), and directly overflows and returns the oil through the overflow valve 1 (5-1); the small cylinder chamber of the hydraulic oil cylinder (12) has no return oil discharged, and the right oil port of the hydraulic pump (3) draws oil from the oil tank (1) through the hydraulically controlled one-way valve 1 (2-1).

9. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 8, characterized in that: The automatic control process of the oil circuit when the actuator loses power suddenly is as follows: the explosion-proof motor (4) is powered off and braked, the hydraulic pump (3) stops and locks, the explosion-proof solenoid valve (9) is powered off and in the normally open position, the high-pressure oil in the accumulator (10) enters the large chamber of the hydraulic cylinder (12) through the left one-way valve of the two-way hydraulic lock (11), and at the same time, the high-pressure oil enters the right control chamber of the two-way hydraulic lock (11), opens the right one-way valve of the two-way hydraulic lock (11), the small chamber circuit of the hydraulic cylinder (12) is connected, and the high-pressure oil pushes the piston rod to extend quickly, closing the actuator urgently; the high-pressure oil in the accumulator (10) has opened the hydraulic control one-way valve (2-1), and the return oil from the small chamber of the cylinder returns to the oil tank (1) through the hydraulic control one-way valve (2-1).

10. The explosion-proof linear electro-hydraulic actuator with emergency shutdown function according to claim 9, characterized in that: When the actuator is powered off and the accumulator loses pressure due to an emergency, the manual control process of the oil circuit is as follows: the explosion-proof motor (4) is powered off and braked, the hydraulic pump (3) stops and locks, the explosion-proof solenoid valve (9) is powered off and in the normally open position, the manual reversing valve (15) is manually switched to the left position, the manual pump (14) is manually pressed to discharge high-pressure oil, and the high-pressure oil enters the large chamber of the hydraulic cylinder (12) through the P port and the B port of the manual reversing valve and the left one-way valve of the two-way hydraulic lock (11), and at the same time, the high-pressure oil enters the right control chamber of the two-way hydraulic lock (11), opens the right one-way valve of the two-way hydraulic lock (11), and the small chamber circuit of the hydraulic cylinder (12) is connected, and the high-pressure oil pushes the piston rod to extend, manually closing the actuator; the high-pressure oil discharged by the manual pump (14) has opened the hydraulic control one-way valve (2-1), and the return oil of the small chamber of the cylinder returns to the oil tank (1) through the hydraulic control one-way valve (2-1).

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