JPH0367877A - Control device of hydraulic elevator - Google Patents

Abstract

PURPOSE:To hold a cage in a predetermined stop position by energizing an electromagnetic selector valve with a floor-mating speed signal to open a hydraulic pipe line and performing a feedback of a speed or a position of the cage, when it is sunk from a regulated position during stopping of the cage. CONSTITUTION:In a speed control device 25, when a cage 5, during its stopping by closing a normally-open contact 30d, is detected for sinking from a regulated position, a floor-mating speed signal is output from a floor-mating pattern generating circuit, while a hydraulic circuit 11a to a jack 3 is opened by selecting an electromagnetic selector valve 11. While a feedback of a cage speed signal 8a from a cage speed detecting device 8 or a cage position is performed, a speed of an electric motor 13, that is, speed of an oil hydraulic pump 12 is controlled through an inverter 23 to perform floor-mating corresponding to the displacement of the cage 5. In this way, delay of action and generation of a shock at the time of starting can be prevented while being possible to hold the cage in a predetermined stop position.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control device for a hydraulic elevator, and more specifically, to a control device for a hydraulic elevator, and more specifically, to prevent a start delay or start shock at the time of start, which is caused by a drop in the car position at the time of stop. The present invention relates to a control device for a hydraulic elevator that prevents such problems.

[Prior Art] Conventional hydraulic control methods for hydraulic elevators include a flow control valve method, a pump control method, and an electric motor rotation speed control method. The flow control valve method drives the electric motor at a constant rotation during lift, returns a fixed amount of oil from the hydraulic pump to the tank, and uses the flow control valve to adjust the amount returned to the tank when a start command is issued. In this way, the speed of the car is controlled by controlling the speed of the car, and when descending, the lowering of the car due to its own weight is adjusted by a flow control valve, thereby controlling the speed of the car. In this method, it is necessary to circulate extra oil when ascending, and when descending, potential energy is consumed to heat the oil, resulting in large energy loss and a significant rise in bending temperature.

To compensate for this drawback, there are a pump control method and a motor rotation speed control method, which send only the necessary amount of oil when ascending and regeneratively brake the electric motor when descending. The pump control method uses a variable displacement pump and makes the discharge amount of the pump itself variable by a control device, which makes the structure of the control device and pump complicated and expensive.

On the other hand, with the technological progress of semiconductors in recent years, for example, as disclosed in Japanese Patent Application Laid-Open No. 57-98477,
A method of controlling the rotation speed of an induction motor over a wide range by changing the voltage and frequency has been considered.The motor rotation speed control method uses this method, and uses a constant discharge pump to control the pump's discharge volume. Variable control is performed by changing the rotation speed of the electric motor, and it is inexpensive and highly reliable.

[Problems to be Solved by the Invention] By the way, hydraulic pumps always have leakage, and due to this leakage, there is a range in which the car does not start even if the hydraulic pump is rotated. That is, as shown in FIG. 4, at time t. If a start command is issued at , the hydraulic pump gradually accelerates and reaches the rotational speed n at time tl, and when the rotational speed exceeds 01, oil in excess of the leakage amount is discharged from the hydraulic pump and the car starts moving.

In this way, when the rotational speed increases rapidly, a large amount of oil, more than the total leakage, is supplied to the pipeline between the hydraulic pump and the check valve, generating high pressure and rapidly pushing the check valve. Opening causes a startup delay and large startup shock and vibration. The car reaches a constant speed at time t2, starts decelerating at time t, and stops at time t4. The hydraulic pump continues to rotate further and stops at time t5.

The starting shock is mainly caused by a significant increase in the rotational speed of the hydraulic pump, so if the rotational speed is gradually increased as shown in FIG.
It starts moving at time tl2 and reaches a constant speed of 1, starts decelerating at time tl3, and reaches time t1.
Stop at 4. Thereafter, the hydraulic pump stops at time tl. In this way, when the rotational speed of the hydraulic pump is gradually increased, the shock at startup becomes smaller, but the startup delay increases.

As described above, the conventional hydraulic control system for hydraulic elevators has various problems.

This invention was made in order to solve the above-mentioned problems that occur with conventional hydraulic elevators. When the car stops, it can be stopped at a predetermined position with smooth movement, and it also solves the problems caused by hydraulic pump leaks, etc. To provide a control device for a hydraulic elevator that does not cause a delay in the operation of a car at startup or a startup shock by immediately correcting the shift even if the stop position shifts.

[Means for Solving the Problems] A control device for a hydraulic elevator according to the present invention includes a pattern generating means for controlling the rotation speed of an electric motor by outputting a speed signal according to a predetermined pattern when the elevator goes up and down; A normally closed solenoid valve installed in the pipe between the hydraulic pump and the jack, which is connected to and driven by the jack, outputs a speed signal based on the detected value of the elevator car's lifting speed near the stop position, and adjusts the rotational speed of the motor. The normally-closed solenoid valve is configured to be energized when each of the speed signals is output, and to open the valve.

[Function] In the floor alignment command means of the present invention, when a stopped car sinks below a predetermined landing floor position, the car speed detection means detects this movement and corrects the movement command based on this detection. It outputs a speed signal to control the rotational speed of the motor.

Furthermore, when the speed signal is output, the normally closed solenoid valve is energized, so the valve opens, and oil from the hydraulic pump is forced into the jack, returning the car to the specified position and aligning it with the floor.

[Embodiment] FIG. 1 is a block diagram of a control device for a hydraulic elevator according to an embodiment of the present invention. In the figure, (1) is the car hoistway, (2) is the cylinder buried in the pit of this hoistway (1), (3) is the pressure oil filled in the cylinder (2),
(4) is a plunger whose expansion and contraction position is controlled by this pressure oil (3), (5) is a cage attached to the top of plunger (4), (5a) is a car floor, and (6) is a car floor (5a).
), (7) is the landing floor, (8> is the car speed detection device installed in the hoistway (1) via the rope (8b) connected to the car (5>), (8a
) is the car speed signal.

<11) always functions as a check valve, and the electromagnetic coil (Il
(1-1a) is an electromagnetic switching valve that is switched when the cylinder (b) is energized and conducts in the opposite direction;
) and the electromagnetic switching valve (11) to supply a pressure surface. (12) is reversibly rotated, and the tube (12a
), (13) is a three-phase induction motor that drives the hydraulic pump (12), and (I4) is a three-phase induction motor (I3). A speed generator that detects the rotation speed of the tube (15a), (15)
The ura tank (16) is a thin section detection device that detects curved sections of the mlj tank (15). R, S, T are three-phase AC power supplies, (21
) is a rectifier circuit that converts three-phase alternating current into direct current, (22) is a capacitor that smoothes this direct current, (23) is an inverter that controls the pulse width of direct current to generate variable voltage, variable frequency three-phase alternating current, ( 24) converts DC into three-phase AC power supplies R, S,
The regenerative inverter (25) that returns to T is the speed signal (14a) of the speed generator (14) and the oil temperature detection device (16).
> oil temperature signal (] (ia) and car speed signal (8a)
The operation signal (30d) generated by the normally open contact (30d) is closed from when a start command is issued until a stop command is issued.
a) and are manually operated speed control devices, respectively, and the signal (25
a) to control the inverter (23).

(31) is a relay, which is energized when the motor pattern signal (55a) described later (Fig. 2) is output, and the normally open contact (3
1, a) to (31, c) are closed, and the electric motor (13>) is connected to the inverter (23>).

FIG. 2 is a block diagram showing the configuration of the speed control device (25) in FIG. 1. In the figure, (40) is a floor alignment command circuit that outputs a floor alignment direction and speed signal corresponding to the position, (41U) is an upward travel pattern generation circuit, and a speed command signal ( 30da)
This results in an upward traveling pattern, and the deceleration command signal (9a
) decreases manually and becomes a constant low speed, and when the stop command signal (1, Oa) is manually applied, the pattern becomes zero and the car (5) stops. In addition, (4, 1D> is a downward running pattern generation circuit, and the above mentioned upward running pattern generation circuit (
41U) and the lifting and lowering patterns perform symmetrical movements.

(41Ua) is an upward contact that remains closed during upward operation, (4], Da) is a downward contact that remains closed during downward operation, (41, IJb), (41Db) are the above Similarly, the upper and lower contacts are closed during the floor alignment command, (43) and (44) are NOT gates, (45
0) and (45D) are respectively the floor alignment command pattern generation circuits during ascending and descending, and (46) are the outputs of the traveling pattern generation circuit (41U) or (41D) and the floor alignment pattern generation circuit (45U) or ( This is an adder that adds the pattern signal (45a) from 45D) and outputs the pattern signal.

(47) converts the speed signal (14a) into the pattern signal (4[i
A conversion circuit that converts the level to the same voltage level as a), (
48) is a subtracter that takes the difference between the output of the adder (46) and the output of the conversion circuit (47), <49) is a transmission circuit that transmits the output of the subtracter (48) at a predetermined amplification degree, and (50) ) is the frequency command signal ω by adding the output of the transmission circuit (49) and the output of the conversion circuit (47). (51) is the frequency command signal ω of the adder (50). A function generating circuit (52) outputs a linear voltage command signal V for a frequency command signal ω. This is a reference sine wave generation circuit that outputs a signal (25a) to the speed control device (25) based on the voltage command signal V and the voltage command signal V so that a sine wave three-phase alternating current is output from the inverter (23).

(53) is a conversion circuit that matches the car speed signal (8a) with the pattern signal level; (54) is a subtractor that compares the speed pattern and the output signal (53a) of the conversion circuit (53) and calculates the difference; 55) is an adder, (56) is an integrator,
Detects the input car speed signal (8a) as a position point,
A stop command signal (9a) and a deceleration command signal (
ioa). Further, (56a) is a positional deviation corresponding signal corresponding to the deviation from the normal stop position.

In the hydraulic elevator control device according to the present invention having the above configuration, for example, if the car (5) is stopped and there is a call in the ascending direction, a start command is issued after the door of the car (5) is closed. , upward running pattern generation circuit (41
The driving pattern signal is output from the oil tank (1), and the oil is output from the oil tank (1
5), pipe (15a), hydraulic pump (12), pipe (12
a) The oil is forced into the cylinder (2) via the electromagnetic switching valve (11) and the pipe (lla), and the car (5) rises by an amount corresponding to the amount of oil, and the speed is increased by the car speed signal (8a). Since the car is returned, the car (5>) runs according to the running pattern. The hydraulic pump (12>) is accelerated and eventually reaches a constant speed.

When the car (5) reaches a predetermined position in front of the destination floor, a deceleration command signal (9a) is output, and the pattern signal of the upward traveling pattern generation circuit (41U) gradually decreases until it finally outputs a - constant value. , the car (5) continues to rise at a slow speed,
A stop command signal (10a) is output and the machine stops.

Furthermore, in the descending operation of the car (5), the car speed pattern is symmetrical to the above-mentioned ascending operation, so the electric motor (13) is controlled in reverse while controlling the descending operation of the car (5>. When the stopped car (5) receives a call in the downward direction, a start command is output, and in response to various signals, a running pattern signal is output from the downward running pattern generation circuit (41D), the car (5) descends, and the goal is reached. The basic movements until stopping at the floor are performed in the same way as when ascending.

The car (5) is stopped by the stop command signal (10a),
When the pattern signal (46a) from the running pattern generation circuit (41U) and (41o) disappears, the electromagnetic switching valve (
11) is released, the check valve is closed, and the relay (31) is also released, so the inverter (23)
and the electric motor (13) are disconnected.

While the car (5) is stopped, if the pressure on the hydraulic pump (12) side becomes lower than the pressure on the Ja Soki (3) side due to the weight of the car (5), for example, the car (5) gradually lowers. . Due to this descent, a car speed signal (8a) is output from the car speed detection device (8), which passes through a conversion circuit (53) and outputs a signal (53a), which is input to a subtractor (54>) and then output from the car (5). At the same time, the deceleration command signal (10a) due to the descent of the car (5) becomes "L", and a signal based on the car speed signal <8a> via the conversion circuit (53>) is issued. (53a) is inputted to the integrator (56), from which a car position signal (56a) is output, and a floor alignment pattern signal (45a) according to the car position is generated by the signal from the floor alignment command circuit (40). It is output from the floor matching pattern generation circuit (450).This causes the adder (46)
A pattern signal (46a) is generated between the subtractor (48) and the relay (31) and the electromagnetic switching valve (11) are energized again, and the car (5) is activated while rotating the electric motor (i3) at a low speed.
〉 back to its normal position.

1 FIG. 3 is a block diagram showing a speed control device according to another embodiment of the present invention, which includes a subtracter (54) and an adder (55).
The parts other than the normally open contact (30e) provided between the
These are exactly the same parts as the parts with the same symbols in the figure.

The normally open contact (30e) is the normally open contact UOd of the embodiment shown in FIG.
), this is a contact that closes when a start command is issued during the call run, and this normally open contact (30d) is open when not during the call run, so the conversion circuit (53) The system generates a floor alignment speed signal corresponding to the position of the car (5) without performing feedback.In other words, after the car (5) stops, the pump discharge pressure changes to the car load side. When the car (5) sinks from its normal position due to the pressure becoming lower than the pressure, the deceleration command signal becomes “L” and the integrator (5)
6) outputs a car position signal (5ea), so the floor alignment command button circuit (450) outputs a speed pattern signal corresponding to the car position to rotate the electric motor (13). This rotation increases the pump discharge amount, and the cage (5)
As the car rises, a pattern signal (
45a) changes gradually and moves the car (5>) while controlling the electric motor (13>), so smoother floor alignment operation can be performed.

[Effects of the Invention] As described above, according to the present invention, when the car sinks from the specified position while the car is stopped, the solenoid switching valve is energized by the output of the bed alignment speed signal, opens the hydraulic pipe, and the car is moved. By performing speed or position feedback, the car is configured to issue a floor alignment signal to the electric motor in response to the amount of deviation of the car from its normal position, so the car can be maintained at a predetermined stop position through smooth floor alignment operations. At the same time, it is possible to obtain a hydraulic elevator that is free from delay in car operation and no start-up shock at the time of start-up.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is a block diagram showing an example of the configuration of the speed control device shown in FIG. 1, and FIG. 3 is a block diagram showing another example of the configuration of the speed control device. , FIG. 4, and FIG. 5 are diagrams for explaining the operation of a conventional hydraulic elevator at the time of starting and stopping. In the figure, (3) is jack, (5) is kako, (8 is
) Car speed detection device, (8a) Car speed signal, (1
1) is a solenoid switching valve (normally closed solenoid valve), (Ila), (1
2a) is a pipe, (12) is a hydraulic pump, (13) is an electric motor, (40) is a floor alignment command circuit, (410) is an upward traveling pattern generating circuit, (41, D) is a downward traveling pattern generating circuit, ( 45U), (45D) is a floor alignment pattern generation circuit, (4, 5a). (48a) is a pattern signal (velocity signal), (53) is a conversion circuit, and (56) is an integrator.

Claims (1)

[Claims] A pattern generating means for outputting a speed signal according to a predetermined pattern when the elevator goes up and down to control the rotational speed of the electric motor, a hydraulic pump that is driven in connection with the rotation of the electric motor, and the elevator speed of the car in the vicinity of the stop position. a speed detection means for detecting the speed, a floor alignment command means for controlling the rotation speed of the electric motor by outputting a speed signal based on the output signal of the speed detection means, and a conduit between the hydraulic pump and the jack. A control device for a hydraulic elevator, comprising: a normally closed solenoid valve which is energized when each of the speed signals is output.