JP3045256B2 - Hydraulic elevator control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for smoothly starting and stopping an elevator.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 61-550 discloses this type of apparatus.
The invention related to No. 75 has been conventionally known. In this conventional apparatus, a hydraulic pump is driven by the driving force of a three-phase electric motor, and the rotation speed of the three-phase electric motor is controlled by an inverter control mechanism. An important factor influencing the riding comfort of the hydraulic elevator is to prevent the occupant from feeling the vibration at the time of starting. Therefore, in this conventional device, the amount of leakage of the hydraulic pump during low-speed rotation is converted into data, and when the discharge amount of the pump becomes equal to or greater than the amount of leakage at startup, a predetermined on-off valve is opened to operate the hydraulic cylinder. I have to. Then, in order to detect the leakage amount, the pump pressure, oil temperature, pump rotation speed, pump leakage amount, and the like are detected, and the detection signals are corrected and input to the traveling pattern generation circuit to control the inverter control mechanism. ing.

[0003]

In this conventional device,
A high-level and expensive sensor for detecting the pressure, the oil temperature, the pump rotation speed, the pump leakage amount, and the like must be used, and there has been a problem that it can only be used for a large elevator. An object of the present invention is to provide a control device that can be used in a small elevator such as a home use.

[0004]

SUMMARY OF THE INVENTION The present invention provides a hydraulic cylinder for vertically moving a car, a hydraulic pump for supplying hydraulic oil to the hydraulic cylinder, and a three-phase electric motor for driving the hydraulic pump. An inverter control mechanism for electrically controlling the three-phase electric motor, an electromagnetic on-off valve provided between the hydraulic pump and the hydraulic cylinder, and a hydraulic cylinder.
Deceleration signal transmission circuit that outputs a deceleration signal according to the moving position of
Outputs stop signal according to road and hydraulic cylinder movement position
Control of a hydraulic elevator equipped with a stop signal transmission circuit
When the device is connected in parallel with the above-mentioned solenoid on-off valve,
Both are free pistons when the solenoid on-off valve is in the closed position.
Is located on the hydraulic pump connection side by the action of the spring,
The pressure on the pump connection side is higher than the pressure on the hydraulic cylinder connection side.
Pressure rose to move free piston when high
Position of the free piston of the pressure balancer
A pair of position sensors for detecting the said position sensor, and a sequence control circuit connected to each of the deceleration signal transmitting circuit and a stop signal transmitting circuit, the moving position of the free piston of the pressure compensator is detected by the position sensor, the The solenoid on-off valve opens and closes according to the signal from the position sensor.
In addition, the above-mentioned pressure balancer has a high pressure before the solenoid on-off valve opens.
The characteristic is that the pressure on the pressure side is transmitted to the low pressure side .

[0005]

Since the present invention is configured as described above, for example, when the three-phase electric motor is rotated forward during the ascending, the free piston of the pressure balancer moves from the position corresponding to the hydraulic pump connection side of the solenoid on-off valve. Move to the position corresponding to the hydraulic cylinder connection side. When this situation is detected by the position sensor and transmitted to the sequence control circuit, the solenoid on-off valve switches to the open position, and the hydraulic pump discharge oil is supplied to the hydraulic cylinder. Therefore, when the electromagnetic on-off valve is opened as described above, the pressure on the hydraulic pump side is transmitted to the hydraulic cylinder side via the pressure balancer.

[0006] When the three-phase electric motor is rotated forward during lowering, the free piston of the pressure balancer moves to a position corresponding to the hydraulic cylinder connection side. When this movement is detected by the position sensor and transmitted to the sequence control circuit, the inverter control mechanism operates to reverse the three-phase electric motor. When the three-phase electric motor rotates in the reverse direction, the pressure on the hydraulic pump connection side decreases, so that the free piston moves again to a position corresponding to the pump connection side. In this process, the pressure on the hydraulic cylinder side is transmitted to the hydraulic pump side via the pressure sensor.

[0007]

According to the control apparatus for a hydraulic elevator of the present invention, when the hydraulic cylinder is opened and closed when the hydraulic cylinder is raised and lowered, the circuit pressure on the high pressure side is reduced via the pressure balancer before the solenoid valve is opened. Has already been communicated to
There is no shock at the start.

[0008]

In the illustrated embodiment, a non-leak type solenoid valve 4 is connected to a main passage 3 connecting a hydraulic cylinder 1 of a telescopic type and a hydraulic pump 2 rotatable in both forward and reverse directions. The solenoid on-off valve 4 normally keeps a closed position shown in the figure, but switches to an open position by exciting its solenoid 5.

A pressure balancer 6 is provided in the main passage 3, and this pressure balancer 6 is connected in parallel with the electromagnetic on-off valve 4. Further, the pressure balancer 6 is provided with a free piston 7 and is divided into a pump side chamber 8 and a cylinder side chamber 9. A spring 10 is provided in the cylinder side chamber 9, and the spring force of the spring 10 is weak enough to overcome the fiction resistance of the free piston 7. The capacity of the pressure balancer 6 is set so as not to affect the moving position of the hydraulic cylinder 1 even if the free piston 7 moves.

A ring (not shown) made of a permanent magnet is fitted around the free piston 7,
The tube portion of the pressure balancer 6 is made of a non-magnetic material. A pair of position sensors 11 and 1 that sense the magnetism of the free piston 7 are provided around the pressure balancer 6.
2 are provided.

The hydraulic pump 2 rotates by receiving the driving force of the three-phase electric motor 13. During the linking operation between the hydraulic pump 2 and the three-phase electric motor 13, the rotation is stopped to determine whether or not the rotation has stopped. A sensor 14 is provided. The three-phase electric motor 13 as described above is controlled by the inverter control mechanism 15. This inverter control mechanism 1
5 controls frequency of the hydraulic pump 2 by frequency conversion,
The discharge amount is controlled.

The inverter control mechanism 15 as described above
Are connected to a sequence control circuit 16 and controlled according to an output signal of the sequence control circuit 16. And
The sequence control circuit 16 includes the position sensor 1
Deceleration signal transmitting circuits 17 and 18 for detecting the moving position of the hydraulic cylinder 1 and outputting a deceleration signal in addition to the positions 1 and 12
And a stop signal transmitting circuit 19 that also outputs a stop signal,
20 and call signal button 2 for commanding up or down
1 is connected. Further, the output signal of the sequence control circuit 16 is supplied to the inverter control mechanism 1 as described above.
5, but is also output to the solenoid 5 of the solenoid on-off valve 4.

Reference numeral 22 in the figure denotes a non-leak type electromagnetic on-off valve for emergency use, which normally keeps the closed position shown in the figure, and energizes its solenoid 24 with a battery not shown to bring it to the open position. It is made to switch. A throttle valve 23 for manually adjusting the opening degree is provided upstream of the electromagnetic on-off valve 22.

Next, the operation of this embodiment will be described. Now, when the elevator is stopped, the electromagnetic on-off valve 4 holds the illustrated closed position and the hydraulic pump 2 is stopped. In this state, since a pressure proportional to the load of the car is generated in the hydraulic cylinder 1, the pressure on the cylinder side becomes higher than the pressure on the pump side with respect to the solenoid on-off valve 4. Accordingly, the pressure in the cylinder-side chamber 9 of the pressure balancer 6 also becomes higher than the pressure in the pump-side chamber 8, and the free piston 7 is maintained at the illustrated lowered position. In this state, the switch function of the position sensor 11 is kept on.

Next, when the call signal button 21 is pressed to output a rising signal to the sequence control circuit 16, the sequence control circuit 16 operates the inverter control mechanism 15 to gradually accelerate the three-phase electric motor 13 in the forward direction. And
When the discharge amount of the hydraulic pump 2 exceeds the leakage amount, the pressure of the solenoid on-off valve 4 on the pump side increases. When the pressure in the pump-side chamber 8 of the pressure balancer 6 becomes higher than the pressure in the cylinder-side chamber 9 as the pressure increases, the free piston 7
Moves against the spring 10 and turns off the switch function of the position sensor 11.

When the switch function of the position sensor 11 is turned off at the time of ascending, a signal of the off state is sent to the sequence control circuit 1.
Enter 6 When the sequence control circuit 16 receives the off signal from the position sensor 11, it excites the solenoid 5 of the solenoid on-off valve 4 to switch it to the open position and accelerates the rotation of the hydraulic pump 2. As described above, the solenoid on-off valve 4 opens slightly after the start of the hydraulic pump 2, but at this time, the pressure on the pump side is reduced by the pressure balancer 6.
, The hydraulic cylinder 1 can smoothly shift to the high-speed movement.

When the hydraulic cylinder 1 extends and reaches a predetermined position, the deceleration signal transmitting circuit 17 outputs a deceleration signal to the sequence control circuit 16. Upon receiving the deceleration signal, the sequence control circuit 16 operates the inverter control mechanism 15 to reduce the rotation of the three-phase electric motor 13 and reduce the discharge amount of the hydraulic pump 2. When the hydraulic cylinder 1 further extends while decelerating, the stop signal transmitting circuit 19 outputs a stop signal to the sequence control circuit 16 this time. Upon receiving this signal, the sequence control circuit 16 demagnetizes the solenoid 5 of the solenoid on-off valve 4, switches it to the closed position, and stops the hydraulic pump 2.

When the electromagnetic on-off valve 4 is closed and the hydraulic pump 2 is stopped, the pressure in the pump-side chamber 8 of the pressure balancer 6 becomes lower than the pressure in the cylinder-side chamber 9, so that the free piston 7 returns to the position shown in the figure. .

When the call signal button 21 is pressed to output a descending signal to the sequence control circuit 16, the sequence control circuit 16 operates the inverter control mechanism 15 to slowly accelerate the hydraulic pump 2 in the forward direction. Hydraulic pump 2
Is accelerated in the forward direction, the pressure in the pump side chamber 8 of the pressure balancer 6 increases as in the case of ascent, the free piston 7 is moved against the spring 10, the position sensor 11 is turned off, and the position sensor 12 is turned off. turn on.

When the ON signal is input from the position sensor 12 to the sequence control circuit 16 at the time of inputting the descending signal, the sequence control circuit 16 provides a reverse rotation signal to the inverter control mechanism 15 at this time. Thereby, the hydraulic pump 2
Stops for a moment while decelerating, and then reverses direction. When the pump reverses, the pressure in the pump-side chamber 8 of the pressure balancer 6 becomes lower than the pressure in the cylinder-side chamber 9, so that the free piston 7 moves in the direction of the pump-side chamber 8, and the position sensor 12 is turned off again.

When the OFF signal of the position sensor 12 is input, the electromagnetic on-off valve 4 is excited to switch it to the open position. Also at this time, the solenoid on-off valve 4 opens slightly later than the reverse rotation of the hydraulic pump, but at this time, since the pressure on the cylinder side is transmitted to the pump side via the pressure balancer 6, the hydraulic cylinder 1 is smoothly operated. Can descend.

When the hydraulic pump 2 rotates in the reverse direction while the electromagnetic on-off valve 4 maintains the open position as described above, the load of the car acts on the circuit, so that the hydraulic pump 2 functions as a hydraulic motor and functions as a three-phase electric motor. Attempt to speed up the rotation of 13. However, when the speed of the motor 13 is increased by the rotating magnetic field generated at the supply frequency of the inverter, the increase in speed is suppressed by regenerative braking in which electric power generated by the three-phase power generation operation is converted into heat by an external resistor. Therefore, an error or a high speed is controlled to be constant.

The hydraulic cylinder 1 is controlled while the descending speed is suppressed.
When contracted and reaches a predetermined position, the deceleration signal transmission circuit 18 outputs a deceleration signal to the sequence control circuit 16.
Upon receiving the deceleration signal, the sequence control circuit 16 operates the inverter control mechanism 15 to reduce the rotation of the three-phase electric motor 13 and reduce the contraction speed of the hydraulic cylinder. When the hydraulic cylinder 1 further contracts while decelerating, the stop signal transmission circuit 20 outputs a stop signal this time. When the stop signal is output, the inverter control mechanism 15 outputs a forward rotation signal, and thus the forward rotation starts after the three-phase electric motor 13 stops.

When the electric motor 13 stops for a moment, the rotation stop sensor 14 detects the stop, and the sequence control circuit 16 operates to demagnetize the solenoid 5 and close the electromagnetic on-off valve 4. If the electric motor 13 rotates forward as described above with the electromagnetic on-off valve 4 closed, the pressure in the pump side chamber 8 of the pressure balancer 6 increases, and the free piston 7 moves against the spring 10. This free piston 10
The switch function of the position sensor 11 is turned off by the movement of. When the off signal of the position sensor 11 is output, the hydraulic pump 2 stops, and the car of the hydraulic cylinder 1 also stops.

As described above, the electric motor 13 is caused to rotate forward once at the time of lowering, so that the discharge pressure of the hydraulic pump 2 is transmitted to the hydraulic cylinder 1 via the pressure balancer 6. Therefore, the stop of the hydraulic cylinder 1 becomes very smooth.

When a power failure or system abnormality occurs, the electromagnetic on-off valve 22 is switched to the open position using a battery (not shown). If the opening of the throttle valve 23 is manually controlled, the hydraulic cylinder 1 is lowered by the weight of the car. Accordingly, when the throttle valve 23 is lowered to the desired position, the throttle valve 23 can be closed and the position can be maintained.

According to the control device of this embodiment, the timing at which the electromagnetic on-off valve 4 is switched to the open position is detected by the movement of the free piston 7 of the pressure balancer 6. Also,
The pressure balancer 6 can suppress an imbalance in pressure due to an operation delay or a response delay of the electromagnetic on-off valve 4 and suppress an impact at the time of startup.

[Brief description of the drawings]

FIG. 1 is a circuit diagram.

FIG. 2 is a graph showing a relationship between an electromagnetic on-off valve, a pump rotational speed, and a car ascending or descending speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic cylinder 2 Hydraulic pump 4 Solenoid on-off valve 6 Pressure balancer 7 Free piston 11 Position sensor 12 １３ 13 Three-phase electric motor 15 Inverter control mechanism 16 Sequence control circuit 17 Deceleration signal transmission circuit 18 １９ 19 Stop signal transmission circuit 20 〃

Claims (1)

(57) [Claims] 1. A hydraulic cylinder for vertically moving a car, a hydraulic pump for supplying hydraulic oil to the hydraulic cylinder,
A three-phase electric motor for driving the hydraulic pump; an inverter control mechanism for electrically controlling the three-phase electric motor; an electromagnetic on-off valve provided between the hydraulic pump and the hydraulic cylinder; Deceleration signal according to moving position
Deceleration signal transmission circuit that outputs
A stop signal transmission circuit that outputs a stop signal according to the position
The above-mentioned electromagnetic opening and closing
Connected in parallel with valve and solenoid on-off valve closed position
When the free piston is
Is located on the pump connection side, and the pressure on the hydraulic pump connection side is
When the pressure becomes higher than the pressure on the
Pressure balancer to move tons and the pressure balancer
A pair of position sensors that detect the movement position of the free piston
When, a sequence control circuit connected to each of the position sensor, the deceleration signal transmitting circuit and a stop signal transmitting circuit, the moving position of the free piston of the pressure compensator is detected by the position sensor, according to a signal from the position sensor Open and close the solenoid on-off valve, and the pressure balancer
A control device for a hydraulic elevator , wherein a pressure on a high pressure side is transmitted to a low pressure side before an on-off valve is opened .