JPH09240933A - Control device of hydraulic elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide constantly stable starting characteristics without receiving influence of inverter noise and provide starting characteristics to shorten starting time at the time of lowering. SOLUTION: A device is for controlling quantity of pressure oil fed from a hydraulic pump 7 to a hydraulic jack 2 at the time of driving to raise a car 1 in accordance with a car speed command value by variation of output frequency of an inverter device 13 to be given to an electric motor 8 of the hydraulic pump 7 in accordance with pressure and temperature detected by sensors 16, 17 to detect pressure and temperature of pressure oil flowing in the hydraulic jack 2 and to control quantity of pressure oil circulating from the hydraulic jack 2 to the hydraulic pump 7 at the time of driving the car 1 for lowering, a flow rate change-over valve 11 which closes at the time when the car 1 is in a motion stand-by state and a check valve 9 are provided on a piping between the hydraulic jack 2 and the hydraulic pump 7, and the flow rate change/over valve 11 is opened at the time when the check valve 9 is an open state by providing a decompression valve 18 in parallel to the flow rate change-over valve 11.

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 a hydraulic elevator in which an AC motor included in a hydraulic pump is rotationally driven by an inverter device.

[0002]

2. Description of the Related Art As an example of a conventional hydraulic elevator control device, there is a system in which an inverter device is used to drive an AC electric motor at a variable speed to control the rotational speed of a hydraulic pump. In this method, when the elevator stops, the pressure on the hydraulic pump side drops to atmospheric pressure. Therefore, at the time of the next start, there is a problem that the start vibration is generated at the time of start due to the pressure difference between the load pressure on the hydraulic jack side and the riding comfort is impaired.

In order to solve this problem, pressure matching control is performed so that the load pressure on the hydraulic jack side and the pressure on the hydraulic pump side are equalized for the purpose of alleviating the vibration at the time of starting, and after equalizing the pressures, Recently, a structure designed to control an elevator according to a predetermined speed pattern has been developed.

FIG. 5 is a block diagram for explaining an example of a conventional pressure adjustment control system of this kind. A flow control valve 9 is provided in the middle of the hydraulic pipe 6 for opening and closing the hydraulic pipe 6, and the hydraulic pipe is also provided. 6, pressure sensors 17 and 35 are provided on the hydraulic jack 2 side and the hydraulic pump 7 side, respectively.
The pressure on the hydraulic pump 7 side is increased by the pressure oil discharged from the pressure sensor 3, and the pressure sensor 3 detects the pressure on the hydraulic pump 7 side.
The pressure detection signal from the hydraulic pump 7 is fed back to the speed control device 20a so that the pressure detection signal in the speed control device 20a becomes equal to the pressure detection signal detected by the pressure sensor 17 on the hydraulic jack 2 side. This is a method of controlling the rotation speed of the AC motor 8 by the rotation speed, specifically, the output frequency of the inverter device 13. As other configurations, the car 1, the plunger 3, the pulley 4, the rope 5, the oil tank 12, the oil temperature sensor 16, and the DC power supply 31 are provided.

[0005]

However, in the pressure matching control system as shown in FIG. 5, the output signal of the pressure sensor 35 for detecting the pressure boosting amount especially on the hydraulic pump 7 side due to the inverter noise generated by the inverter device 13. Is unstable and the control accuracy is lowered, and a special device for stabilizing the output signal of the pressure sensor 35 must be added.

There is also a problem that the starting time during the descent operation becomes long because the pressure must be adjusted even at the descent start of the car 1 during the descent operation. Further, pressure sensors 17, 35 are provided on both sides of the control valve 9 for opening and closing the hydraulic pipe 6.
Need to be provided.

The present invention has been made to solve the above-mentioned conventional problems, and has a simple control valve circuit configuration.
A stable equilibrium starting characteristic can be obtained by detecting the pressure equilibrium state by the operation of the control valve without being affected by the inverter noise peculiar to the inverter device and performing the elevator start control, and the flow control valve when descending. It is an object of the present invention to provide a hydraulic elevator control device capable of obtaining a starting characteristic in which the starting time is shortened by eliminating the need to adjust the pressure on both sides of the control valve for opening and closing the hydraulic pipe by performing the speed control by.

[0008]

In order to achieve the above object, the invention according to claim 1 is arranged between a hydraulic jack for raising and lowering a car and a tank for storing pressure oil supplied to the hydraulic jack. Connected to the pipe, a hydraulic pump for supplying the hydraulic oil in the tank to the hydraulic jack, and a part of the pipe, which is closed when the car is in the operation standby state. A flow rate switching valve that holds and releases the pressure in the pipe, and is provided in the pipe between the hydraulic pump and the hydraulic jack,
A check valve that is closed when the car is in an operation standby state and opens when the hydraulic pump operates; a valve open detector that outputs a signal when the open state of the check valve is detected; It is connected to a shunt formed in parallel with the hydraulic pump and the check valve, and is in a closed state when the car is in an operation standby state, and controls the pressure oil discharged from the hydraulic jack into the tank. And a pressure reducing valve that is connected in parallel to the flow rate switching valve and that is configured to make the pressure on the hydraulic pump side lower than that on the hydraulic jack side when the car is in an operation standby state. An inverter device for controlling a power supply frequency of an AC electric motor included in the hydraulic pump, a sensor for detecting pressure and temperature of pressure oil flowing through the hydraulic jack, and a pressure detected by the sensor Based on the temperature and the temperature, the reference of the output frequency of the inverter device is output, and when there is a detection signal from the valve open detector, an open command is given to the flow rate switching valve, and when the car descends, A control device for a hydraulic elevator, comprising: a speed control device that gives an opening degree command to the flow control valve based on a speed pattern of a car.

In order to achieve the above object, the invention according to claim 2 is characterized in that a hydraulic jack for raising and lowering a car and a pipe arranged between a tank for storing pressure oil supplied to the hydraulic jack; A hydraulic pump connected to a pipe for supplying the hydraulic oil in the tank to the hydraulic jack; and a part of the pipe, which is in a closed state when the car is in an operation standby state, Is provided in the pipe between the hydraulic pump and the hydraulic jack for holding and releasing the pressure of the, and is in the closed state when the car is in the operation standby state, and is opened when the hydraulic pump operates. Check valve, a valve opening detector that outputs a signal when an open state of the check valve is detected, and a connection formed in parallel to the hydraulic pump and the check valve, Basket It is in a closed state in the operation standby state and is connected in parallel to the flow rate control valve for controlling the pressure oil discharged from the hydraulic jack into the tank and the flow rate switching valve, and the car operates. In a standby state, a proportional relief valve for making the pressure on the hydraulic pump side lower than that on the hydraulic jack side, an inverter device for controlling the power supply frequency of an AC electric motor included in the hydraulic pump, and the hydraulic jack. There is a sensor for detecting the pressure and temperature of the circulating pressure oil and a reference signal of the output frequency of the inverter device based on the pressure and temperature detected by the sensor, and a detection signal from the valve open detector. When the car is descending, an opening command is given to the flow control valve, and the flow control valve is commanded to the flow control valve based on the speed pattern of the car. A speed control means for providing the opening command is a control system for a hydraulic elevator which comprises a.

According to the invention according to claim 1 or 2, when the rising operation of the car is started, the equilibrium state of the cylinder load pressure and the hydraulic pump pressure is changed to the open state of the check valve by increasing the hydraulic pump pressure. By switching to the car speed pattern running by detecting by the car, it is possible to obtain good starting characteristics by enabling starting control that is not affected by the device variations of the pressure sensor that detects the pump pressure and the inverter noise generated by the inverter device. You can Further, since the hydraulic pump rotation speed is controlled by the variable speed control of the electric motor by the inverter device, the landing accuracy can be improved, and the speed control with high accuracy can be performed to realize energy saving. On the other hand, in the descending operation, the speed is controlled by the flow control valve, so pressure adjustment at the time of starting is unnecessary, and the descending starting time is shortened, and a power regeneration device or a resistance regeneration device required when adopting inverter control is required. A hydraulic elevator system can be configured.

In order to achieve the above object, the invention corresponding to claim 3 is a control device for a hydraulic elevator using a stroke sensor as a valve open detector according to claim 1 or 2.

According to the invention according to claim 3, the stroke sensor can instantaneously detect the movement (stroke) of the valve body due to the pressure change, and in the case of the stroke sensor, the input signal is input as a digital signal. In addition, it can be converted into an electrical signal and input to the speed control device without being affected by noise generated by the inverter device 13. Therefore, by reliably detecting the pressure balance state without control delay and shifting to speed control by the car speed pattern, it is possible to shorten the starting time and obtain good starting characteristics.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 shows the entire system configuration of a hydraulic elevator using a control device according to a first embodiment of the present invention. The car 1 is suspended by a rope 5 wound around a pulley 4 which is moved up and down by a plunger 3 of a hydraulic jack 2. Between the hydraulic pump 7 and the hydraulic jack 2, a hydraulic pipe 6 having a shunt branched into two is disposed on the way, and flow rate switching valves such as electromagnetic switching valves 10 and 18 are disposed in the shunt. A check valve 9 is arranged in the hydraulic pipe 6 between the electromagnetic switching valve 10 and the hydraulic pump 7, and the check valve 9 and the electromagnetic switching valve 10 and the oil tank 12 are connected.
A flow rate control valve 11 is provided in the hydraulic pipe 6 that connects the two. The hydraulic pump 7 is for adjusting the amount of pressure oil from the oil tank 12. The hydraulic pump 7 is connected to an AC electric motor 8 for driving the hydraulic pump main body, for example, an induction motor. The AC motor 8 is configured to control the power supply frequency of the AC motor 8 so that the car 1 travels at a predetermined speed pattern by an inverter device 13 that converts DC power from a DC power supply 31 into AC power. Has been done.

The check valve 9 opens and closes the hydraulic pipe 6, the electromagnetic switching valve 10 holds and releases the pressure of the hydraulic pipe 6, and the flow control valve 11 is connected to the oil tank 12. This is for controlling the amount of oil discharged. Further, the pressure reducing valve 18, when the electromagnetic switching valve 10 is closed,
The pressure between the electromagnetic switching valve 10 and the check valve 9 is adjusted to be lower than the pressure between the electromagnetic switching valve 10 and the hydraulic jack 2.

The check valve 9 is provided with a valve open detector 19 for detecting the open / closed state of the check valve 9, and the valve open detector 19 is specifically discharged from the hydraulic pump 7. The pump side pressure of the check valve 7 and the physical operation amount (stroke) of the valve at the moment when the pressure equilibrium state between the electromagnetic switching valve 10 and the check valve 7 is broken by the pressure oil are detected. It is adapted to be input to the speed control device 20 that operates. The AC electric motor 8 is provided with a rotation speed detector 14 for detecting the rotation speed of the electric motor, and a detection output of the detector 14 is input to a speed control device 20 described later.

Further, the hydraulic jack 2 and the electromagnetic switching valve 10
A pressure sensor 17 for detecting the pressure in the hydraulic pipe 6 is provided in the hydraulic pipe 6 between the two, and the detection output is input to a speed control device 20 described later. Further, a car speed detector 15 for detecting the traveling speed is arranged in the car 1, and the detection output is input to a speed control device 20 described later.

As shown in the schematic diagram of FIG. 2, the speed control device 20 includes an operation command section 21, a speed control switching command section 22, and an electric motor speed control for controlling the rotational speed of the AC motor 8 when the car 1 is raised. Part 23, and the flow control valve 1 when descending
1, a speed control unit 24 for controlling the valve opening degree, a starting pattern control unit 25, and a car speed pattern control unit 26. An interlocking contact A having a normally open contact and a normally closed contact that operates when a pressure balance control completion signal is obtained from the valve open detector 19 is provided.

The pressure reducing valve 18 controls the pressure in the hydraulic pipe between the electromagnetic switching valve 10 and the check valve 9 when the electromagnetic switching valve 10 is in the closed state. The pressure is adjusted to be lower than the pressure in the pipe.

The valve open detector 19 detects the valve pressure at the moment when the pressure side of the check valve 9 and the pressure balance between the electromagnetic switching valve 10 and the check valve 9 are broken by the pressure oil discharged from the hydraulic pump 7. The physical operation amount (stroke) is detected, and the normally open contact of the interlocking contact A is closed when the pressure balance control completion signal is obtained from the valve open detector 19, and from the interlocking contact A having the normally closed contact. It is configured.

Next, the operation of the hydraulic elevator control device configured as described above will be described. When the car 1 is stopped, the electromagnetic switching valve 10, the check valve 9, and the flow control valve 11 are closed. Therefore, the check valve 9 and the electromagnetic switching valve 1
The pressure between 0 is a pressure lower than the cylinder load pressure of the hydraulic jack 2 by the circuit of the pressure reducing valve 18 at a constant ratio with respect to the pressure corresponding to the loaded weight in the car 1.

When the ascending operation is selected by the destination direction selection switch (not shown), the operation command section 21 outputs a door opening command. After that, the rising operation command output from the operation command unit 21 is input to the speed control switching command unit 22, the operation logic is switched to speed control by the electric motor 8, and the rising operation command is input to the electric motor speed control unit 23. It The ascending operation preparation command output from the operation command unit 21 starts the door closing operation of the car 1. When a motor control preparation command is output from the motor speed control unit 23,
The electric motor 8 is excited and is in a ready state.

Then, when the ascending operation command is output from the operation command unit 21, the inverter device 13 changes the rotation speed of the electric motor 8 based on the starting control electric motor rotation command value generated by the starting pattern control unit 25. The flow rate discharged by the hydraulic pump 7 that is controlled and is connected to the electric motor 8 is controlled.

The pressure oil discharged from the hydraulic pump 7 gradually raises the check valve 9 on the hydraulic pump 7 side, so that the electromagnetic switching valve 1
When the pressure on the hydraulic pump side 7 becomes higher than the pressure on the cylinder side of the hydraulic jack 2 of the check valve 9 held at 0, the check valve 9 is opened. The open state of the valve body of the check valve 9 is detected by the valve open detector 19, and the valve open detector 19 outputs a pressure balance control completion signal, which is given to the electric motor speed control unit 23.

At this time, the pressures on the primary side and the secondary side of the check valve 9 are in a balanced state. At the same time, it depends on the balance control completion signal. At the same time, the electric motor speed control unit 23 outputs a valve opening command for the electromagnetic switching valve 10 in response to the pressure balance control completion signal, and the electromagnetic switching valve 10 is opened.

Since the normally open contact of the interlocking valve A is closed and the normally closed valve is opened by the pressure balance control completion signal, the command from the speed control switching command unit 22 is sent from the start pattern control unit 25 to the car speed pattern control unit 26. The inverter device 13 is switched based on the car speed pattern electric motor rotation command value generated by the car speed pattern control unit 26.
The flow rate discharged by the hydraulic pump 7 controlled by the above flows into the hydraulic jack 2 to raise the plunger 3 and control the speed of the car 1. Then, the balance control completion signal output from the valve open detector 19 is the motor speed control 23.
Causes the normally open contact of interlocking valve A to close and the normally closed contact to open,
The discharge from the hydraulic pump 7 controlled by the inverter device 13 is switched from the starting pattern control unit 25 to the car speed pattern control unit 26 based on the electric motor rotation command value for the car speed pattern generated by the car speed pattern control unit 26. The flow rate of the flow into the hydraulic jack 2 raises the plunger 3 and the speed of the car 1 is controlled.

On the other hand, in the case of descending operation, the operation command section 2
When the command for descending operation is output from 1, the speed control switching command unit 22 switches to speed control by the valve opening of the flow control valve 11, and the operation command is input to the speed control unit 24 by the valve opening. The electromagnetic switching valve 10 is constantly in an open state in response to a valve opening command from the speed control unit 24 based on the valve opening.

When the descending operation command is output, the flow control valve 1 is generated by the flow control valve command value generated based on the car speed pattern output from the speed control unit 24 according to the valve opening.
The valve opening of the car 1 is controlled, and the flow rate of the car 1 is regulated by the weight of the car 1 to the oil tank 12, and the plunger 3 is lowered to control the speed of the car 1.

Next, the operation of the hydraulic circuit of the present invention will be described with reference to FIG. When the elevator is in the door-closed standby state and is stopped, the electromagnetic switching valve 10 is constantly closed. Then, the car 1 is opened by the driving command due to the generation of the call in the ascending direction, and the passenger gets in. The cylinder load pressure of the hydraulic jack 2 changes as the loaded weight increases depending on the number of passengers. At this time, since the electromagnetic switching valve 10 is closed, the pressure between the electromagnetic switching valve 10 and the check valve 9 is reduced by the circuit of the pressure reducing valve 18 by the pressure set at a constant ratio, and the cylinder load pressure is reduced. Lower pressure. A rising operation command is output, and the inverter device 13 controls the electric motor 8. As a result, the electric motor 8
When the rotation speed of the hydraulic pump 7 connected to the hydraulic pump 7 increases, the check valve 9 is discharged by the pressure oil discharged from the hydraulic pump 7.
The primary side pressure rises. When the rising primary pressure of the check valve 9 becomes higher than the corrected secondary pressure lower than the cylinder load pressure, the check valve 9 is opened. As a result, the electromagnetic switching valve 10 can be opened, and it is possible to prevent the starting vibration due to the abrupt pressure change when the car speed pattern traveling is started.

Further, since the stroke sensor is attached to the check valve 9 as the valve open detector 19, the movement (stroke) of the valve body due to the pressure change can be instantly detected, and in the case of the stroke sensor, the input signal is detected. Unlike an analog signal that changes at any time, such as a pressure sensor, since it is input as a digital signal, it can be converted into an electrical signal without being affected by noise generated by the inverter device 13 and input to the speed control device 20. it can. Therefore, by reliably detecting the pressure balance state without control delay and shifting to speed control by the car speed pattern, it is possible to shorten the starting time and obtain good starting characteristics.

<Second Embodiment> Next, the second embodiment of the present invention will be described.
The embodiment will be described with reference to FIG. The difference from the above-described first embodiment is that the pressure reducing valve 18 shown in FIG.
Instead of providing the above, the proportional electromagnetic relief valve 30 is additionally provided between the electromagnetic switching valve 10 and the check valve 9 and between the check valve 9 and the pump 7.

The proportional electromagnetic relief valve 30 in this case is
It is possible to proportionally variably set the relief pressure setting. When the cylinder load pressure increases due to a change in the load weight of the car 1 when the electromagnetic switching valve 10 is in the open state,
The pressure between the electromagnetic switching valve 10 and the check valve 9 is set so as not to be constantly higher than the relief pressure value set by the proportional electromagnetic relief valve 30. Therefore, by variably setting the relief pressure in proportion to the set value, the pressure between the electromagnetic switching valve 10 and the check valve 9 can be adjusted as in the above-described embodiment.

Further, in the embodiment shown in FIG. 4, the cylinder load pressure value which changes depending on the loaded weight is input from the pressure sensor 17, and the speed control device 20 is operated according to the pressure value.
At, the relief pressure value is calculated from a predetermined relational expression, and a setting command value corresponding to the relief pressure is output to the proportional electromagnetic relief valve 30 to variably set the relief pressure. Therefore,
It is possible to variably set the pressure between the electromagnetic switching valve 10 and the check valve 9 to be lower than the load pressure value of the hydraulic jack 2 so that good starting characteristics can be obtained corresponding to the load pressure of the hydraulic jack 2 each time. Therefore, it is possible to perform finer adjustment than the decompression method with the constant ratio described above.

[0033]

According to the hydraulic elevator control apparatus of the present invention described above, the following effects can be obtained. At the start of the ascending operation of the car, the valve open state due to pressure increase is detected by the operation of the valve element without using the pressure sensor, and the motor rotation speed follows the speed pattern from the state where the jack side pressure and the pump side pressure are balanced. It is possible to provide good starting characteristics that are not affected by noise generated by the inverter device and variations in the pressure sensor device by controlling
In addition, by using the traveling control by the flow control valve, it is possible to shorten the starting time because the starting control of the descending operation is unnecessary, and the power regeneration device or the resistance regeneration device required for the inverter control is not necessary. Cost can be reduced.

[Brief description of drawings]

FIG. 1 is a system configuration diagram for explaining a first embodiment of a control device for a hydraulic elevator according to the present invention.

FIG. 2 is a control block diagram showing a detailed configuration of the speed control device of FIG.

FIG. 3 is an explanatory diagram of a traveling pattern of FIG.

FIG. 4 is a system configuration diagram for explaining a second embodiment of a control device for a hydraulic elevator according to the present invention.

FIG. 5 is a system configuration diagram showing an example of a conventional hydraulic elevator control device.

[Explanation of symbols]

 1 ... Car 2 ... Hydraulic jack 3 ... Plunger 4 ... Pulley 5 ... Piping 7 ... Hydraulic pump 8 ... AC motor 9 ... Check valve 10 ... Electromagnetic switching valve 11 ... Flow control valve 12 ... Oil tank 13 ... Inverter device 14 Rotation speed detector 15 Car speed detector 17 Pressure sensor 18 Pressure reducing valve 19 Open valve detector 20 Speed controller 30 Proportional electromagnetic relief valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroki Yoshida No. 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu factory

Claims (3)

[Claims] 1. A hydraulic jack for raising and lowering a car and a pipe arranged between a tank for storing pressure oil to be supplied to the hydraulic jack; and a hydraulic pipe for connecting the hydraulic oil in the tank to the hydraulic pressure. A hydraulic pump for supplying to the jack; a flow rate switching valve that is provided in a part of the pipe, is in a closed state when the car is in an operation standby state, and holds and releases the pressure in the pipe; A check valve that is provided in a pipe between the hydraulic pump and the hydraulic jack, is in a closed state when the car is in an operation standby state, and opens when the hydraulic pump operates, and an open state of the check valve. A valve opening detector that outputs a signal when detected, and a hydraulic circuit and a check valve that are connected in parallel to a shunt formed in parallel, and are in a closed state when the car is in an operation standby state, Ja A flow rate control valve for controlling pressure oil discharged from the tank into the tank, and the flow rate control valve are connected in parallel, and when the car is in an operation standby state, the pressure on the hydraulic pump side is A pressure reducing valve for lowering the pressure from the hydraulic jack side, an inverter device for controlling the power supply frequency of the AC motor included in the hydraulic pump, a sensor for detecting the pressure and temperature of the pressure oil flowing through the hydraulic jack, Based on the pressure and temperature detected by the sensor,
While outputting the reference of the output frequency of the inverter device, when there is a detection signal from the valve open detector, an open command is given to the flow rate switching valve, and the speed pattern of the car when the car descends. And a speed control device for giving an opening degree command to the flow control valve based on the above. 2. A pipe provided between a hydraulic jack for raising and lowering a car and a tank for storing pressure oil to be supplied to the hydraulic jack; and a pipe connected to the pipe for connecting the pressure oil in the tank to the hydraulic pressure. A hydraulic pump for supplying to the jack; a flow rate switching valve that is provided in a part of the pipe, is in a closed state when the car is in an operation standby state, and holds and releases the pressure in the pipe; A check valve that is provided in a pipe between the hydraulic pump and the hydraulic jack, is in a closed state when the car is in an operation standby state, and opens when the hydraulic pump operates, and an open state of the check valve. A valve opening detector that outputs a signal when detected, and a hydraulic circuit and a check valve that are connected in parallel to a shunt formed in parallel, and are in a closed state when the car is in an operation standby state, Ja A flow rate control valve for controlling pressure oil discharged from the tank into the tank, and the flow rate control valve are connected in parallel, and when the car is in an operation standby state, the pressure on the hydraulic pump side is A proportional relief valve for making the pressure lower than that of the hydraulic jack, an inverter device for controlling the power supply frequency of the AC electric motor of the hydraulic pump, and the pressure and temperature of the pressure oil flowing through the hydraulic jack. A sensor, based on the pressure and temperature detected by the sensor,
While outputting the reference of the output frequency of the inverter device, when there is a detection signal from the valve open detector, an open command is given to the flow rate switching valve, and the speed pattern of the car when the car descends. And a speed control device that gives an opening degree command to the flow control valve based on the above. 3. The hydraulic elevator control device according to claim 1, wherein a stroke sensor is used as the valve open detector.