KR960011572B1 - Control valve device for oil-pressure elevator - Google Patents

Abstract

The device is designed to use in a hydraulic elevator which controls quantity of pressure oil to be supplied to or discharged from a hydraulic cylinder. The device includes : a hydraulic cylinder (4) for moving up/down a car (1); a normal/reverse rotating hydraulic pump (21) for pumping hydraulic operating oil; a solenoid valve (10) for opening a main check valve (9); and another solenoid valve (11) for closing the main check valve (9).

Description

Control valve device for hydraulic elevator

1 is a conventional hydraulic control circuit diagram.

2 is a hydraulic control circuit diagram filed by the applicant.

3 is a detailed view showing the configuration and operation of the pilot operated main check valve of FIG. 2, in which 3a is a normal, 3b is a descending, 3c is a rising, and 3d is an emergency.

4 and 5 are cross-sectional views and perspective views showing the check valve movable body of FIG.

6 is a hydraulic control circuit diagram of the present invention.

7 is a configuration and action diagrams taken from the main check valve in FIG. 6, 7a is a normal, 7b is ready, 7c is an operation, 7d is an emergency.

* Explanation of symbols for main parts of the drawings

1: car 4: hydraulic cylinder

5: hydraulic hose 6: stop valve

7: Manual lowering valve 8: Minimum pressure setting relief valve

9: Pilot Operated Main Check Valve 9a: Groove

10: Solenoid valve for opening the main check valve

11: Solenoid valve for closing the main check valve

12: Pilot Operated Relief Valve 13: Unloading Solenoid Valve

14: check valve 15: orifice

16 cylinder pressure detector 17 hydraulic pump pressure detector

18: speed control device 20: three-phase induction motor

21: Reverse rotation hydraulic pump 22: Main check valve side piping line

23: hydraulic tank side piping line 24: pipeline

26: manihold block 27, 28: cover

29, 32: spring 30: urethane O-ring

31: piston 33: stopper nut

35: pilot tube 40, 41: first and second block cover

42: subblock 43: main check valve spring

44: piston for forced closing of the main check valve

45: return spring 46: piston for forcibly opening the main check valve

47: piston spring 50, 51: pilot tube

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve device for a hydraulic elevator, and more particularly, for a hydraulic elevator, which is suitable for a hydraulic elevator in a manner of controlling the supply of pressurized oil to a hydraulic cylinder or a flow rate discharged from a hydraulic cylinder by controlling the rotation speed of the hydraulic pump. A control valve device.

A circuit diagram of a conventional hydraulic elevator is shown in FIG. In the figure, 1 is a car carrying a passenger, 2 is a main rope and the car 1 is connected to the car 1 through a pulley 3 coupled to the ram end of the hydraulic cylinder 4. 6 is a pilot operated main check valve, and the pilot operated main check valve 6 is connected to the hydraulic hose 5. 10 is a pilot tube connected to the opening solenoid valve 8 and the closing solenoid valve 9. 11 is a throttle, which throttles the back pressure of the pilot operated unload relief valve 12. 13 is a relief valve and 14 is a solenoid valve for unloading. 15 is a check valve, and 16 is a tank side pipe which sends hydraulic hydraulic fluid refluxed from the pilot operated unload relief valve 12 to the hydraulic tank 20. 18 is an oil filter for purifying hydraulic hydraulic oil sent to the forward and reverse hydraulic pump 17, 19 is a three-phase induction motor which operates by receiving the command power source 25 from the inverter 24. 21 is a cylinder side pressure detector, 22 is a hydraulic pump side pressure detector, 22a is an output signal which sends the pressure signal detected by the hydraulic pump side pressure detector 22 to the speed control apparatus 23, and the speed control apparatus 23 Is connected to the inverter 24.

Hereinafter, the operation will be described with reference to FIG. 1.

When the driving operation command of the car 1 occurs, the speed control device (by the pressure signal transmission path 22a of the cylinder-side pressure detector 21 and the pressure signal transmission path 22a of the hydraulic pump-side pressure detector 22) An electric motor speed command is generated in 23 and applied to the inverter 24. Inverter 24 generates a three-phase alternating current of a variable voltage variable frequency corresponding to the speed command during transmission to drive the three-phase induction motor 19. At this time, the forward and reverse hydraulic pump 17 connected to the three-phase induction motor 19 rotates forwardly so that the car 1 rises, and when it is equal to the cylinder pressure, a car speed command is generated and the three-phase induction motor corresponding thereto ( As the rotational speed of 19) increases, the discharge flow rate of the forward and reverse hydraulic pump 17 also increases, and the discharged hydraulic oil pushes up the check valve of the pilot operated main check valve 6 and moves up the hydraulic cylinder through the hydraulic hose 5. Delivered to (4) to raise the car (1) up. When the car 1 approaches the stationary bed, the rotation speed of the three-phase induction motor 19 decreases, and when the discharge flow rate of the forward and reverse hydraulic pump 17 linked thereto becomes zero, the pilot operated main check valve 6 Serves as a general check valve to stop the hydraulic oil from the hydraulic cylinder (4) to completely stop the car (1).

When the falling operation command is generated, the three-phase induction motor 19 is driven in the forward direction as in the case of ascending, and when the discharge pressure of the forward and reverse hydraulic pump 17 becomes equal to the cylinder side pressure, the opening solenoid valve 8 is turned on ( ON) and the closing solenoid valve 9 is also turned on, so that the pressure on the hydraulic cylinder 4 side, which is always generated by the weight of the car 1, is generated through the pilot pipe 11 The hydraulic pressure is transferred to the pilot operation chamber 7 in the check valve 6 to forcibly open the pilot operated main check valve 6, and then the hydraulic cylinder 4 to the forward and reverse hydraulic pump 17 according to the car speed command. The hydraulic oil flows, the flow rate discharged from the hydraulic cylinder 4 is controlled while regeneratively braking by the three-phase induction motor 19 to control the flow rate discharged from the hydraulic cylinder 4, and the car 1 descends and stops. Almost to the floor 3 By reducing the rotational speed of the induction motor 19 to reduce the discharge flow rate from the hydraulic cylinder 4, when the car 1 reaches the stop layer, the opening solenoid valve 8 is turned off to turn off the pilot operated main The pilot operated main check valve 6 is completely checked by discharging the pressure oil of the pilot operation exhaust chamber 7 of the check valve 6 to the hydraulic tank 20 and simultaneously turning off the closing solenoid valve 9. After switching to the valve function, the hydraulic elevator is stopped.

On the other hand, when the discharge pressure of the forward and reverse hydraulic pump 17 is higher than the set pressure of the pilot operated unload relief valve 12, the pressure oil discharged as the forward and reverse hydraulic pump 17 passes through the pilot operated unload relief valve 12 and passes through the tank. It flows to the side pipe 16 side, and is discharged | emitted to the hydraulic tank 20. FIG.

In addition, when the temperature of the hydraulic oil is less than the temperature at the rated use, the unloading solenoid valve 14 is turned on to pass the hydraulic oil to the pilot operated unload relief valve 12 to raise the oil temperature, check valve (15) An operating signal is applied to the solenoid valve 8 for opening when the car 1 descends, but the hydraulic tank 20 does not generate cavitation due to the negative pressure when the forward and reverse hydraulic pump 17 reverses due to inoperation. Allow hydraulic oil to be supplied.

In the conventional hydraulic elevator, the pilot pressure applied when opening the pilot operated main check valve 6 is supplied from the hydraulic cylinder 4 through the pilot pipe 11 so that the opening solenoid valve 8 malfunctions during driving. If it continues to be ON, the pilot operated main check valve 6 will be forcibly opened and there is a risk that the car 1 will continue to descend. In addition, the spool of the check valve in the pilot operated main check valve 6 will not function as a complete check valve when the oil temperature rises and the viscosity of the hydraulic fluid decreases. This occurs and the car 1 is lowered. That is, there is a risk that the check valve does not function as the viscosity of the hydraulic oil changes. In addition, since there is no valve for manually lowering the car 1 in an emergency, it is a risk factor because the pilot operated main check valve 6 must be used to manually lower the car 1.

Accordingly, the present inventors have prevented the pilot operated main check valve from being forcibly opened by a malfunction of the opening solenoid valve in order to solve the conventional defect as described above. Control valve for hydraulic elevator that prevents internal leakage and prevents the main rope from deviating from the pulley of the hydraulic cylinder by attaching an emergency lowering manual valve and a minimum pressure setting relief valve. The device was invented and filed with a patent application No. 93-22245.

As shown in FIG. 2, the control valve device for the pre-application hydraulic elevator is connected to the main rope 2 connected to the ground through the pulley 3 of the ram upper portion of the hydraulic cylinder 4, The hydraulic cylinder 4 is connected to the stop valve 6 connected to the manifold block 26 by a hydraulic hose 5.

In the manifold block (26), 15 is an orifice, and the pilot pressure passing therethrough flows through the emergency lowering manual valve (7) and the minimum pressure setting relief valve (8) to the hydraulic tank side piping line (23). have.

9 is a pilot operated main check valve, and the pipe 35 of the pilot operated main check valve 9 is connected to a solenoid valve 10 for opening the main check valve and a solenoid valve 11 for closing the main check valve. The pressure oil delivered to the main check valve opening solenoid valve 10 passes through the orifice 15.

12 is a pilot operated relief valve, 13 is an unloading solenoid valve used when operating the pilot operated relief valve 12 as an unload valve, and 14 is a check valve 14, which is rotated forward and backward from the pipe 23. It is used to supply pressure oil to the hydraulic pump 21.

36 is an oil filter for purifying the hydraulic oil supplied to the forward and reverse hydraulic pump 21, and 35 is a hydraulic tank for storing the hydraulic oil.

25 is a pressure gauge, and the stop valve 6 connected to the pressure gauge 25 may transmit or block pressure to the pressure gauge 25.

16 is a cylinder side pressure detector, 17 is a hydraulic pump side pressure detector, 16a is a cylinder side pressure detector output signal transmission path, and 17a is a hydraulic pump side pressure detection output signal transmission path.

18 is a speed control device, wherein the cylinder-side pressure detector output signal transmission path 16a and the hydraulic pump-side pressure detection output signal transmission path 17a are connected to the speed control device 18, and the speed control device 18 Is connected to an inverter 19.

20 is a three-phase induction motor and is connected to a forward and reverse hydraulic pump 21, and the inverter 19 is connected to a three-phase induction motor 20.

3a to 3d specifically illustrate a part of the pilot operated main check valve in the entire block of the manifold block, and as shown therein, a check valve movable body 9 'is provided inside the block 26'; Pistons 31, which push the check valve movable body 9 'by the pilot back pressure, are inserted so as to be slidable left and right, respectively, and are supported by springs 29 and 32, and hold on both ends of the block 26'. The block covers 27 and 28 are coupled, and a stopper nut 33 is screwed to an end of the piston 31, and a stopper nut of the piston 31 is attached to one side block block 28. 33) The cover for protection is fixed.

In addition, a urethane o-ring 30 is coupled to the check valve movable body 9 'to prevent internal leakage.

The spring 29 holds the check valve movable body 9 'toward the closing side, the spring 32 holds the piston 31 to always return, and the stopper nut 33 is advanced by the pilot back pressure. The stroke is limited to the piston 31 to determine the opening degree of the check valve movable body 9 '. In FIG. 3, 10 is a solenoid valve for opening the main check valve, 10 is a solenoid valve for closing the main check valve, 15 is an orifice, 9b is a flow port on the hydraulic cylinder 4 side, and 9c is a forward and reverse hydraulic pump 21 Each flow port is shown.

4 and 5 show a cross-sectional view and a perspective view of the check valve movable body 9 ', wherein the check valve movable body 9' is provided with several grooves 9a (four in the figure) at its ends. The hydraulic oil is passed between the grooves a.

As shown in Fig. 2, the control valve device for the pre-source hydraulic elevator as described above has a cylinder-side pressure detector output signal transmission path 16a of the cylinder-side pressure detector 16 when a driving operation of the car 1 occurs. The motor speed command is generated by the speed controller 18 by the hydraulic pump side pressure detection output signal transmission path 17a of the hydraulic pump side pressure detector 17 and applied to the inverter 19. The inverter 19 generates three-phase alternating current of variable voltage frequency corresponding to the motor speed command to drive the three-phase induction motor 20. At this time, the forward and reverse hydraulic pump 21 connected to the three-phase induction motor 20 is the hydraulic cylinder that is always generated by the weight of the car (1) when the forward rotation so that the car (1) rises ( 4) When the side pressure and the forward and reverse hydraulic pump 21 are equal, a car speed command is generated and the rotation speed of the three-phase induction motor 20 increases accordingly, so that the discharge flow rate of the forward and reverse hydraulic pump 21 is also increased. 3C, the discharged pressure oil pushes up the check valve of the pilot operated main check valve 9 and is transferred to the hydraulic cylinder 4 through the hydraulic hose 5 to raise the car 1. When the car 1 approaches the stationary bed, the rotation speed of the three-phase induction motor 20 decreases, and when the discharge flow rate of the forward and reverse hydraulic pump 21 linked thereto becomes zero, the pilot operated main check valve 9 3 serves as a general check valve to stop the oil from the hydraulic cylinder (4) to completely stop the car (1), the pilot operated main check valve (9) is maintained as shown in Figure 3a.

When the falling operation command is generated, it is driven in the full rotation of the three-phase induction motor 20 as in the case of ascending, and when the discharge pressure of the forward and reverse hydraulic pump 21 is equal to the pressure of the hydraulic cylinder side, the solenoid valve for opening the main check valve ( 10) ON and the main check valve closing solenoid valve 11 is also turned ON, the pressure on the forward and reverse hydraulic pump 21 side through the orifice 15 and the pilot pipe 3B Similarly, the piston 31 forcibly opens the pilot operated main check valve 9. At this time, since the piston 31 has a piston stopper nut 33 to limit the stroke in which the piston 31 can move to the maximum, the opening opening of the pilot operated main check valve 9 is also limited, so that Maximum descent speed is limited. The reason for opening the pilot operated main check valve 9 by equalizing the pressure of the hydraulic cylinder 4 with the pressure of the forward and reverse hydraulic pump 21 at the time of lowering is to prevent starting shock during the lowering. With the pilot operated main check valve 9 open, the hydraulic oil flows from the hydraulic cylinder 4 to the forward and reverse hydraulic pump 21 according to the car speed command, and the rotation speed of the forward and reverse hydraulic pump 21 is changed to a three-phase induction motor. By controlling the flow rate discharged from the hydraulic cylinder 4 while sacrificial braking, the car 1 is lowered, and the rotational speed of the forward and reverse hydraulic pump 21 is reduced by almost reaching the stationary floor, When the flow rate discharged from the cylinder 4 decreases and the car 1 reaches the stop layer, the main check valve opening solenoid valve 10 is turned off, and the main check valve closing solenoid valve 11 is also turned off. By turning off the piston 31 to the hydraulic tank 35 which continues to be pushed, the pilot operated main check valve 9 is completely switched to the check valve function, and then the operation of the hydraulic elevator is stopped. Kinda.

When the car 1 is to be stopped, only the main check valve closing solenoid valve 11 is turned OFF even when the main check valve opening solenoid valve 10 is ON, as shown in FIG. 3D. Even if the pilot operated main check valve (9) is closed even if you can ensure the safety at all times.

In addition, even if unintentional power supply to the main check valve opening solenoid valve 10 is turned on, if no pressure is generated in the forward and reverse hydraulic pump 21, no pilot pressure is generated, so that the pilot operated main check valve 9 is Since the car 1 never opens, the car 1 does not fall.

As shown in FIG. 4, the urethane O-ring 30 is coupled to the pilot operated main check valve 9 so that the oil hydraulic pressure of the hydraulic cylinder 4 remains inside even if the viscosity of the hydraulic hydraulic fluid is high due to the high oil temperature as shown in FIG. 3a. It can be prevented by the sealing role of the urethane O-ring 30 which flows into the forward rotation hydraulic pump 21 by the leak, and the car 1 falls.

In FIG. 2, the emergency lowering manual valve 7 is a valve used to lower the car 1 to the nearest lower floor in case of power failure or emergency, and is the lowest pressure continuously connected to the emergency lowering manual valve 7. The set relief valve (8) is operated when the emergency descending manual valve (7) passes through the emergency descending manual valve (7) if the car (1) cannot move up and down for any reason in the hoistway. The pressure is the weight except the weight of the car (1) acts and there is a risk of the main rope (2) of Figure 2 to escape from the pulley (3), so the emergency lowering manual valve (7) to the weight of the car (1) It is possible to prevent the main rope (2) from being separated from the li (3) by setting to operate only at the pressure by the weight of the included weight.

On the other hand, when the discharge pressure of the forward and reverse hydraulic pump 21 is higher than the set pressure of the pilot operated relief valve 12, the pressure oil discharged from the forward and reverse hydraulic pump 21 passes through the pilot operated relief valve 12 and passes through the hydraulic tank. Flow to the side pipe line 23 is discharged to the hydraulic tank (35).

In addition, when the temperature of the hydraulic oil is below the rated operating temperature, the no-load unloading solenoid valve 13 is turned on to cause the hydraulic oil to pass through the pilot operated relief valve 12 to raise the oil temperature to increase the rated operating temperature. The check valve 14 applies an operating signal to the main check valve opening solenoid valve 10 when the car 1 is lowered, but does not operate, so that the negative pressure is generated when the forward and reverse hydraulic pump 21 reverses. Hydraulic hydraulic fluid is supplied from the hydraulic tank 35 so that cavitation by the gas does not occur.

As described above, when the control valve device for the hydraulic elevator reaches the target floor during the up and down operation, the pressure at both ends of the pilot operated main check valve is almost the same, and the check valve is opened with almost no discharge flow rate of the hydraulic pump. By turning off the solenoid valve for valves and by turning off the solenoid valve forcibly closing the valve, the pilot pressure that continuously pushes the piston is drained to the hydraulic tank, and the main check valve is switched to the check valve function. After the control is continued for a certain time until closing, the operation of the hydraulic elevator is terminated by cutting off the power of the motor. At this time, the main check valve is designed to have a small spring force in order to minimize the pressure loss caused by the spring force of the main check valve during the ascending operation. The check valve did not work well due to the foreign matter caught in the valve spool surface, so that the power of the motor was shut off when the valve was not completely closed, resulting in a risk of a safety accident such as a large stop shock or a car falling.

In addition, in case of emergency such as fixing of elevator, the main check valve is closed by closing the check valve forcibly closed solenoid valve. This is only possible if the valve fails to operate normally there is a risk of a safety accident.

The present invention was devised to solve the conventional defects as described above, which will be described in detail with reference to the accompanying drawings.

FIG. 6 is a hydraulic control circuit diagram of the present invention, and FIG. 7 is a configuration and operation diagram of the main check valve taken from FIG. 6, and as shown in the present invention, the hydraulic cylinder 4 for elevating the car 1 is shown. ) And the main check valve (9) for opening and closing the pilot operated main check valve (9) forcibly opened and closed by the pilot pressure to the pipeline between the forward and reverse hydraulic pump (21) for pumping hydraulic oil. The check valve opening solenoid valve 10 and the main check valve closing solenoid valve 11 to be closed are configured to apply a pilot pressure to the pressure generated by the forward and reverse hydraulic pump 21.

The solenoid valve 10 for opening the main check valve is connected to the main check valve 9 connected to the main check valve side pipe line 22 and the pilot pipe 50 connected between the hydraulic tank side pipe line 23. And the orifice 15 is connected between the main check valve side pipe line 22 and the pilot pipe 50, and the main check valve side pipe line 22 and the main check valve 9 and The outlet port of the solenoid valve 11 for main check valve closing is connected to the said hydraulic tank side piping line 23, respectively.

As shown in Fig. 7, the pilot operated main check valve 9 holds the main check valve movable body 9 'inside the block 26' and the main check valve which is held close to the side of the movable body 9 '. A spring 43, a main check valve forcibly closing piston 44 for pushing the movable body 9 'to the closing shaft, a return spring 45 for returning the main check valve forcibly closing piston 44, and And a piston spring (47) for returning the main check valve forced opening piston (46) for pushing the movable body (9 ') to the open side, and the main check valve forcibly opening piston (46). Piston stopper nut which is coupled to the end of the check valve forced opening piston 46 and restricts the stroke of the main check valve forced opening piston 46 which is advanced by the pilot back pressure to determine the opening degree of the main check valve 9 ( 48).

In FIG. 7, 40 and 41 show the first and second block covers, 42 show the sub block covers, and 46 'shows the urethane bonded to the outer circumferential surface of the movable body 9' to prevent internal leakage. The O-ring is shown and 49 is the piston protective cover.

In addition, the control valve device for a hydraulic elevator of the present invention, the forced closing force of the main check valve (9) is greater than the forced opening force so that when the abnormality occurs, even if the forced opening force is not released, the main check valve (9) is forced by the closing force. When the car 1 reaches the stop layer, the main check valve 9 is provided by the restoring force of the main check valve spring 43 of the main check valve 9 and the piston 44 for forced closing of the main check valve. ) Is closed, and the closing force of the main check valve forced closing piston 44 is larger than the main check valve spring 43. When the safety system is normal, the forced closing force of the main check valve 9 is released. It is configured to operate as a pilot operated main check valve, and forcibly opens the main check valve 9 by the piston 46 for forcibly opening the main check valve to raise and lower the pressure drop by the main check valve spring 43. Choi It is configured to flower.

Hereinafter, the operational effects of the present invention as described above will be described.

First, when there is no operation command, as shown in FIG. 7A, the main check valve opening solenoid valve 10 is kept in a completely closed state.

If there is no abnormality in the safety system when the rising operation command occurs, as shown in FIG. 7B, the main check valve closing solenoid valve 11 is turned on, and the main check valve forcibly closing piston 44 is restored by the spring 45 forcibly. The closing force is released, and at the same time, the speed controller 18 receives the pressure signal 16a of the cylinder-side pressure detector 16 as a command and the pressure signal 17a of the pump-side pressure detector 17 receives the cylinder-side pressure detector. The torque command of the induction motor 20 is generated to match the pressure signal 16a of (16), and the variable voltage variable frequency corresponding to the torque command of the induction motor 20 is generated and three-phase alternating current is applied to the inverter 19. All. The three-phase induction motor 20 is driven by the inverter 19, and the forward and reverse hydraulic pump 21 connected to the induction motor 20 performs forward rotation.

At this time, when the pressure of the hydraulic pump 21 increases, the pressure of the hydraulic pump 21 is supplied to the pilot pipe 50 through the orifice 15, but the solenoid valve 10 for opening the main check valve is turned off so that the flow rate is supplied. More flow rate discharged to the pipe 23, the main check valve opening solenoid valve 10 is not operated.

When the pressure of the hydraulic pump 21 side rises and becomes equal to the pressure of the hydraulic cylinder 4 side, the car 1 speed command is generated. As shown in FIG. 7C, the solenoid valve for opening the main check valve is opened simultaneously with the car 1 speed command. 10 is turned on, and the main check valve forced opening piston 46 is advanced to forcibly open the main check valve 9. At this time, since the pressures at both ends of the main check valve 9 are balanced, no shock occurs when the main check valve 9 is opened, and the main check valve 9 is forcibly opened even when the main check valve 9 is opened. When acting as a shock generated due to the pressure difference due to the spring force of the main check valve spring 45 and the loss for the spring force is also not generated.

According to this speed command, the rotational speed of the three-phase induction motor 20 increases, so that the discharge flow rate of the hydraulic pump 21 increases, whereby the car 1 rises.

Upon reaching the stationary bed, the rotational speed of the three-phase induction motor 20 decreases, and the discharge flow rate of the hydraulic pump 21 linked thereto becomes zero. At this time, the three-phase induction motor 20 receives the hydraulic cylinder pressure at the start. Torque is applied because it must be maintained. When reaching the stop layer, as shown in FIG. 7A, the main check valve opening solenoid valve 10 and the main check valve closing solenoid valve 10 are turned off to release the opening force of the main check valve 9, and the force closing force is applied. The main check valve 9 is closed to shut off the flow path. When the main check valve 9 is completely closed, the torque applied to the three-phase induction motor 20 is released to end the operation.

On the other hand, when the lowering operation command occurs, as in the case of rising, if there is no abnormality in the safety system, as shown in FIG. 7B, the main check valve closing solenoid valve 11 is turned on, and the main check valve forced closing piston 44 returns. When the closing force is released by the spring 45 to release the force, the three-phase induction motor 20 is driven in forward rotation so that the discharge pressure of the hydraulic pump 21 becomes equal to that of the hydraulic cylinder 4, as shown in FIG. When the main check valve opening solenoid valve 10 is turned on, the main check valve forced opening piston 46 moves forward to forcibly open the main check valve 9. At this time, the piston 46 for forced opening of the main check valve has a piston nut 48 to limit the stroke at which the piston can move to the maximum. Therefore, the opening and the hole of the main check valve 9 are limited, so the maximum of the car 1 You will be limited to the descent speed. Therefore, even if the power is cut off while the main check valve 9 is completely open, the car 1 cannot be lowered beyond the specified speed. When the main check valve 9 is opened, the rotational speed of the three-phase induction motor 20 gradually decreases according to the speed command of the car 1 and reversely rotates to perform regenerative braking. Therefore, the flow rate discharged from the hydraulic cylinder 4 Is controlled according to the rotational speed of the hydraulic pump 21 to drive the car 1, and decrease the rotational speed of the three-phase induction motor 20 near the arrival of the stationary floor, and is discharged from the hydraulic cylinder 4 Reduce the flow

When the car 1 reaches the stationary floor, the three-phase induction motor 20 must maintain the pressure of the hydraulic cylinder 4 side at the time of starting, so that torque is applied. Likewise, the main check valve closing solenoid valve 11 and the main check valve opening solenoid valve 10 are turned off to release the forced opening force of the main check valve 9 and the closing force is applied to the main check valve 9. To completely close the flow path, and when the main check valve 9 is completely closed, releases the torque applied to the three-phase induction motor 20 to end the operation.

If the safety system fails during operation or power is not supplied, the main check valve closing solenoid valve 11 is turned off, and the main main check valve forced closing piston 44 forces the main check valve 9. It closes and the fall of the car 1 is prevented. In addition, the forced closing force of the main check valve (9) is larger than the forced opening force, so that the pilot pipe is narrowed by foreign matter or the main check valve opening solenoid valve (10) does not operate normally. To close normally.

As described above, the present invention is different from the closing force of the conventional pilot operated main main check valve using the differential pressure between the cylinder side pressure and the hydraulic pump side pressure and the main check valve spring force. By adding the main check valve to the piston for forced closing of the main check valve, the main check valve can be forcibly closed. To ensure the main check valve is completely closed to force the main check valve to be closed, and if the safety system fails even when the piston for the main check valve forcibly opens to operate in order to allow the hydraulic oil to flow in the reverse direction during the descent operation, Check valve forced closing piston forcibly It is possible to close the check valve, thereby improving the stability of the main check valve.

Claims (7)

The pilot operated main check valve 9 connected to the conduit between the hydraulic cylinder 4 for elevating the car 1 and the forward and reverse hydraulic pump 21 for pumping hydraulic oil can be forcibly opened and closed by pilot pressure. The main check valve opening solenoid valve 10 for opening the main check valve 9 and the main check valve closing solenoid valve 11 for closing the pilot check pressure are generated by the forward and reverse hydraulic pump 21. Control valve device for a hydraulic elevator, characterized in that configured to apply. The solenoid for opening the main check valve according to claim 1, wherein the main check valve (9) connected to the main check valve side pipe line (22) and the pilot pipe (50) connected between the hydraulic tank side pipe line (23). A valve 10 is connected, an orifice 15 is connected between the main check valve side pipe line 22 and the pilot pipe 50, and the main check valve side pipe line 22 and the main check valve. (9) and a control port device for a hydraulic elevator, characterized in that the outlet port of the main check valve closing solenoid valve (11) is connected to the hydraulic tank side piping line (23), respectively. The main check valve according to claim 1, wherein the pilot operated main check valve (9) holds the main check valve movable body (9 ') and the movable body (9') close to the inside of the block (26 '). The main check valve forcibly closing the piston 44 for pushing the valve spring 43 and the movable body 9 'to the closing side, the return spring 45 and the main check body for pushing the movable body 9' to the open side. Control valve device for a hydraulic elevator, characterized in that consisting of a valve forcibly open piston (46), and a piston spring (47). The main check valve 9 according to any one of claims 1 to 3, wherein the forced check force of the main check valve 9 is greater than the force open force so that the main check valve 9 is forced by the force close force even if the force release force is not released when an abnormality occurs. Control valve device for a hydraulic elevator, characterized in that configured to be closed. The method according to any one of claims 1 to 3, wherein when the car (1) reaches the stop layer, the restoring force of the main check valve spring (43) of the main check valve (9) and the main check valve force closing piston (44). By the main check valve (9) is closed, the closing force of the main check valve force closing piston 44 is configured to be larger than the main check valve spring (43). The control valve apparatus for a hydraulic elevator according to any one of claims 1 to 3, wherein the safety check system is configured to release a forced closing force of the main check valve 9 to operate as a pilot operated main check valve. . The method of claim 1, wherein the main check valve (9) is forcibly opened by the main check valve forcibly opening piston (46) during the rise and fall to minimize the pressure loss caused by the main check valve spring (43). Control valve device for hydraulic elevator.