JPH0780643B2 - Hydraulic elevator controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic elevator, and more particularly, to a hydraulic elevator control in which the response of a control system is improved when oil leaks from a hydraulic pump and a car descends. It relates to the device.

[Prior Art] Conventional hydraulic control systems for hydraulic elevators include a flow control valve system, a pump control system, and an electric motor speed control system.
In the flow control valve system, the electric motor is rotated at a constant speed when the car is raised, and the constant discharge amount of oil from the hydraulic pump is returned to the tank.
When a start command is issued, the speed of the car is controlled by adjusting the amount returned to the tank with the flow control valve, and when the car is descending, the car descending due to its own weight is adjusted with the flow control valve to control the car speed. Is. In this method, extra oil is circulated when ascending, and potential energy is consumed for heat generation of oil when descending, so energy loss is large and oil temperature rises significantly.

As a method of compensating for this drawback, there are a pump control method and an electric motor rotation speed control method as a method of giving only the required amount of oil when the car rises and regeneratively braking the electric motor when the car descends. The pump control system uses a variable displacement pump, and the discharge amount of the pump itself is variable by the control device, and the structure of the control device and the pump is complicated and expensive.

On the other hand, with recent technological advances in semiconductors, for example,
As disclosed in JP-A-57-98477, voltage,
A method of controlling the rotation speed of the induction motor over a wide range by changing the frequency has been considered.This is the motor rotation speed control method, which uses a constant discharge type pump and controls the discharge rate of the pump by changing the rotation speed of the motor. It is variably controlled by changing the number and is inexpensive and highly reliable.

[Problems to be Solved by the Invention] By the way, the hydraulic pump always leaks oil during its driving. Therefore, for example, as disclosed in JP-B-64-311, the oil leak amount of the hydraulic pump is There has been proposed a method in which a bias pattern for correcting the speed pattern of the electric motor and a speed pattern corresponding to the speed of the car are superimposed to correspond to the speed of the car.

In this method, in order to prevent a starting shock, the oil pressure is balanced against the weight on the car side in advance, and it is premised that the oil leakage amount of the pump at this low rotation speed is not much different from that at high speed rotation. The car speed is controlled. However, if the oil leakage amount of the hydraulic pump and Q _{L, generally, Q L = K · f (} μ, N, P) to become. Where: Q _L : Pump oil leakage μ: Oil viscosity N: Pump rotation speed P: Pump load pressure K: Pump oil leakage coefficient Therefore, depending on the oil pressure pump, the correction bias pattern at low rotation Since the oil leak correction does not always completely correct the oil leak amount at high speed rotation, that is, at the full speed of the car, there is an error in correcting the oil leak amount of the oil pressure pump by such speed control of the electric motor. May occur. In order to deal with this problem, there is a method of taking out the rotation of the rotating shaft of the governor that is usually installed in the car and feeding back the car speed.In this case, it is provided to prevent malfunction of the governor. Since the response is delayed by a spring or the like, it is generally unsuitable as a means for accurately feeding back the car speed.

On the other hand, it is conceivable to provide a bias pattern to correct the oil leak amount of the hydraulic pump, but in this device, no particular problem occurs when the car rises, but when descending, it depends on the speed signal of the bias pattern at startup. The electric motor rotates in the forward direction and then in the reverse direction. Similarly, when the car descends and the car stops, the above-described reverse rotation shifts to forward rotation according to the bias pattern. When such a forward / reverse transition is made, the electric motor is temporarily stopped, and unless the response operation is speeded up, temporary inertial control may result and the car may be shocked. There was a problem.

The present invention has been made to solve the above problems, and makes it possible to control the delay of the control operation due to oil leakage of the hydraulic pump and accurately control the electric motor when the car descends. The object is to obtain a highly accurate and stable hydraulic elevator control device.

[Means for Solving the Problems] A control device for a hydraulic elevator according to the present invention provides a travel pattern generating means for generating a predetermined travel pattern when an elevator is moved up and down, and a travel pattern of an electric motor according to an oil leakage amount of a hydraulic pump. Bias pattern generating circuit that generates the bias pattern to be corrected and the rope that is connected to the car and stretches along the hoistway are used to continuously detect the car ascending and descending, and the car movement signal is continuously detected when the car ascends and descends. Occurs in the car, the first conversion circuit that converts the car movement signal output from the car lift detection device to the car speed in accordance with the signal level of the running pattern, and detects the rotation of the electric motor. The motor rotation detecting means for generating a rotation signal and the rotation signal output from the motor rotation detecting means are converted into a rotation speed in accordance with the signal level of the traveling pattern. A second conversion circuit that converts the rotation signal and a converter that converts the rotation signal output from the motor rotation detection unit into a rotation angle are provided, and the first conversion circuit, the second conversion convolution, and the converter The control system is configured to feed back the car speed, the rotation speed, and the rotation angle.

[Operation] Since the first conversion circuit in the present invention converts the car movement signal continuously output from the car up-and-down detection device to the car speed and feeds it back to the control system, the responsiveness corresponding to the car speed is excellent. Controlled. Further, the second conversion circuit and the converter convert the rotation signal output from the motor rotation detection means into the rotation speed and the rotation angle and feed them back to the control system, so that the responsiveness when the car descends is fast. Therefore, the influence of oil leakage of the hydraulic pump is suppressed. Therefore, the shock to the car is eliminated, and a smooth descending operation can be obtained.

[Embodiment] FIG. 1 is a configuration diagram of a control device for a hydraulic elevator according to an embodiment of the present invention. In the figure, (1) is a basket (5)
Of the hoistway, (2) is a cylinder embedded in the pit of the hoistway (1), (3) is the pressure oil filled in the cylinder (2), and (4) is the expansion / contraction position by this pressure oil (3). A plunger supported by, (5) a car placed on the top of the punja (4), (5a) a car floor, (6) a load detection device attached to the bottom of the car floor (5a), ( 8) is a rope (8b) stretched along the hoistway and connected to the car (5)
A car up-and-down detection device provided in the hoistway via the circuit detects the up and down of the car (5) continuously, and continuously generates a car movement signal when the car is moved up and down. (11) is an electric gun switching valve that always functions as a check valve, and is switched by energizing the electromagnetic coil (11b) to conduct in the reverse direction.
Reference numeral (11a) is a feed pipe connected between the cylinder (2) and the electromagnetic switching valve (11) to feed hydraulic pressure.

(12) reversibly rotates, and the electromagnetic switching valve (1
A hydraulic pump that sends and receives pressure oil to and from 1), (13) a three-phase induction motor (hereinafter referred to as an electric motor) that drives the hydraulic pump (12), and (14) detects the rotation of the electric motor (13), It is a motor rotation detection means that generates a rotation signal (14a) when rotating, and is composed of, for example, a rotary encoder, and generates a pulse signal when rotating. Hereinafter, in the present embodiment, a rotary encoder will be described as an example of the electric isolator rotation detection means, and the rotation signal will be described as a pulse signal.

(15) is an oil tank that sends and receives pressure oil to and from the hydraulic pump (12) via the pipe (15a), and (16) is an oil temperature detection device that detects the oil temperature of the oil tank (15). R, S, T are three-phase AC power supplies, (2
1) 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 the direct current to generate variable power, variable frequency three-phase alternating current, (24) is a regeneration inverter that returns the DC power regenerated from the electric motor (13) to the three-phase AC power supplies R, S, T, (25) is the load signal (6a) of the load detection device (6),
Closed until the pulse signal (14a) of the rotary encoder (14), the oil temperature signal (16a) of the oil temperature detector (16), the car movement signal (8a), and the start command to the stop command are issued. Operation signal (30d) generated by normally open contact (30d)
a) and the speed control device which inputs respectively, the signal (25a)
To control the inverter (23). A relay (30) closes the normally open contacts (30a) to (30c) when the inverter (23) receives a drive command, and connects the electric motor (13) to the inverter (23).

FIG. 2 is a block diagram showing the structure of the speed control device (25) in FIG. In the figure, (40) is a delay circuit that outputs an output with a predetermined time delay after the normally open contact (30d) is closed, and (41) is a car up / down operation, that is, a normally open contact (30
When the driving signal (30da) generated by the closing of d) is input through the delay circuit (40), it is a traveling pattern generation means for instructing the start of a predetermined traveling pattern for traveling the car (5), and an ascending traveling pattern. It is composed of a generating circuit (41U) and a descending traveling pattern generating circuit (41D). The ascending traveling pattern generation convolution (41U) rises due to the output of the delay convolution (40), decreases when the deceleration command signal (9a) is issued, temporarily decreases to a constant low speed, and becomes zero after a predetermined time. In addition, descending traveling pattern generation circuit (41D)
Performs an operation in which the ascending traveling pattern generation circuit (41U) and the ascending / descending pattern are symmetrical. (41Ua) is an upward contact that remains closed during the upward operation, and (41Da) is a downward contact that continues to be closed during the downward operation.

Reference numeral (42) is a setting bias pattern for initializing the oil leakage amount variation of the hydraulic pump (12), the load, and the oil temperature depending on the oil temperature in advance. For example, in the case of no load, the hydraulic pump is at an oil temperature of 20 ° C. A command for rotating the hydraulic pump (12) is output by the rotation corresponding to the oil leakage amount in (12). Reference numeral (43) is an arithmetic unit, which is operated by the oil temperature signal (16a) and the load signal (6a), and adds and corrects the output of the set bias pattern circuit (42) through the adder (44) by calculation. .

When the normally open contact (30d) is closed, (45) issues a command to rotate at a rotation speed equivalent to the amount of oil leakage of the hydraulic pump (12) at that time, and generates a bias pattern that holds that value. When the circuit issues the stop command signal (10a) based on the car movement signal (8a) output from the car lift detection device (8), the output value becomes zero. (46) adds the output of the running pattern generation circuit (41U) or (41D) and the output of the bias pattern generation convolution (45) to obtain the result of FIG. 3 (c) or FIG. 4 (a) described later. It is an adder that outputs a pattern signal.

(47) is a second conversion circuit for converting the pulse signal (14a) output from the rotary encoder (14) into the same voltage level as the pattern signal, and detects the rotational speed of the electric motor (13). . (48) is a subtractor that takes the difference between the output from the adder (46) side and the output of the second conversion circuit (47), and (49) transmits the output of the subtractor (48) with a predetermined amplification degree. Transmission circuit, (50) is the output of the transmission circuit (49) and the second
The output of the conversion circuit (47) and the frequency command signal ω
₀ is an adder, (51) is a function generating circuit that outputs a linear voltage command signal V to the frequency command signal ω ₀ of the adder (50), and (52) is a frequency command signal ω ₀ and a voltage It is a reference sine wave generating circuit that outputs a signal (25a) based on the command signal V so that a three-phase alternating current of a sine wave is output from the inverter (23).

Reference numeral (53) is a first conversion circuit for matching the car movement signal (8a) output from the car lift detection device (8) to the pattern signal level, and is for detecting the car speed. (54)
Is a subtracter that takes the difference by comparing the speed pattern and the signal of the car movement signal (8a) that has passed through the first conversion circuit (53), (5
6) is an amplifier, (55) is the output of the amplifier (56) and an adder (4
This is an adder that adds the output of 6) and outputs it to the subtractor (48).

The deceleration command signal (9a) and the stop command signal (10a) are issued at the deceleration point and the stop point, respectively, calculated from the travel distance obtained by integrating the car movement signal (8a) by the integrator (not shown). It is a position signal.

(57) is a converter that converts the pulse signal (14a) output from the rotary encoder (14) into a rotation angle, and the output signal (57a) is input to the reference sine wave generation circuit (52), As a result, vector control is performed to improve the current response.

In the hydraulic elevator control device having the above-described configuration, for example, when the car (5) is stopped and there is a call in the ascending direction, a start command is issued to the car (5) after completion of door closing, and the normally open contact is made. (30a), (30b), (30c) are closed and the electric motor (13) is connected to the inverter (23). Also, the normally open contact (30d) is closed, and the bias pattern generation circuit (4
A bias pattern is generated from 5). The inverter (23) outputs a three-phase alternating current of low voltage and frequency according to this bias pattern, and the electric motor (15) has a low rotational speed corresponding to the oil leakage amount of the hydraulic pump (12).
To drive. Therefore, the car (5) does not rise in the bias pattern.

After that, the delay circuit (40) outputs an output, and the ascending traveling pattern generation circuit (41U) outputs a pattern signal. Therefore, the adder (46) outputs a pattern signal including an oil leak, and the hydraulic pump (12) delivers pressure oil in excess of the oil leak amount. Oil is stored in the oil tank (15), pipe (15a), hydraulic pump (12), pipe (12a), electromagnetic switching valve (11), pipe (11).
It is sent to the cylinder (2) by the route of a), raises the car (5) by an amount commensurate with this oil amount, and the car movement signal (8a), that is, car speed, passes through the first conversion circuit (55). A subtractor (54) outputs a deviation signal that is compared and an amplifier (5
The position of the car (5) is controlled by being fed back by the 6) and the adder (55).

When the hydraulic pump (12) is accelerated and reaches a certain speed until the car (5) reaches a predetermined position before the destination floor, a deceleration command is generated by the car movement signal (8a) and the deceleration position signal (9a) is generated. Will output. Due to this output, the pattern signal of the ascending traveling pattern generation circuit (41U) is gradually reduced, and eventually a constant value is output. The car (5) continues to rise at a slight speed, and when the stop position signal (10a) is subsequently output, the traveling pattern further decreases and eventually becomes zero. Similarly, the bias pattern also decreases and becomes zero. Therefore, the output of the adder (46) sharply decreases, and the car (5) stops when the amount of oil in the hydraulic pump (12) becomes smaller than the amount corresponding to the amount of oil leakage.

When the car (5) moves down, the running pattern is the reverse of when it goes up, and the electric motor (13) once rotates in the normal direction, then shifts to the normal rotation, and controls the position of the car (5) while braking. However, basically, the same operation as when rising is performed.

Next, with reference to the diagrams of FIG. 3 and FIG. 4, a comparative explanation will be given between the conventional hydraulic elevator control device and the control device according to the present invention.

FIGS. 3 (a) to 3 (d) are diagrams showing the history up to the actual car speed obtained by the conventional control device, corresponding to the car speed pattern when the car is raised. In the figure, (a) shows the car speed pattern, and (b) shows the change in the car speed feedback amount due to the rotation of the rotating shaft of the speed governor provided in the car. In this case, the feedback amount is (a) ) At the car speed pattern shown in the figure, Δt is caused by the spring of the governor or oil leak of the pump.
Response delay occurs.

In order to restrict the deterioration of controllability due to this response delay, the gain of the amplifier (56) is increased. On the other hand, the pattern of the rotation speed of the electric motor for driving the pump does not cause the response delay Δt as shown in FIG. 7C, so that the control state becomes unstable and the car as shown in FIG. It becomes a pattern of actual speed, a smooth ascending motion cannot be obtained, and riding comfort is extremely deteriorated.

However, in the present invention, the speed controller (25) does not cause a response delay by the car lift detection device (8) so that the rope (8b) reaching the car (5) is interlocked with the lifting motion of the car (5). Since the cage movement signal (8a) is input, the unstable state of the control loop due to the response delay is suppressed, and a smooth cage actual speed pattern as shown in FIG.

FIG. 4 (a) shows a rotation speed pattern of the electric motor when the car is descending. When the car is descending, when the start command is issued, the rotation of the electric motor corresponding to the car speed is normally rotated once, and the oil leakage of the hydraulic pump is lost. After the correction, the traveling pattern is generated and it is reversed. In other words, the pattern of normal rotation low speed-zero speed-reverse rotation speed accelerates in the descending direction. In this case, if the control response of the electric motor is slow in the vicinity of the zero speed of the electric motor, vibration when the car descends as shown in FIG. 4 (b) occurs.

However, in the case of the present invention, the converter (57) and the second converter circuit (47) detect and feed back the rotation angle and the rotation speed of the electric motor (13), and the output signal (57) of the converter (57).
That is, since the control system is configured so that the rotation angle signal is input to the reference sine wave generation circuit (52), the response to the torque change of the electric motor (13) becomes faster, and As shown in c), it is possible to obtain a smooth car actual speed pattern in which the vibration during the descending operation of the car is suppressed.

[Effects of the Invention] As described above, according to the present invention, the car speed, the first conversion circuit, the second conversion circuit, and the converter,
The control system is configured to continuously detect the rotation speed and rotation angle of the electric motor and to feed them back.Therefore, it is possible to perform control with excellent responsiveness corresponding to the car position, and to provide a highly accurate and stable elevator. Control can be achieved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of the speed control device in FIG. 1, and FIG. 3 (a) is a line showing a car speed pattern when a car is raised. Figure, (b) is a diagram showing the amount of car speed feedback by the conventional control device when the car is raised, (c) is a diagram showing the pattern of the number of rotations of the electric motor when the car is raised, (d) is the car rising FIG. 4 (a) is a diagram showing an example of the actual car speed obtained by the conventional control device in FIG. 4, (e) is a diagram showing the actual car speed obtained by the control device according to the present invention when the car is raised, and FIG. A diagram showing the rotation speed pattern of the electric motor when the car is descending, (b) is a diagram showing an example of the actual car speed when descending obtained by the conventional control device, and (c) is the control device according to the present invention. The actual car speed at the time of descent obtained It is a diagram showing a. In the figure, (1) is a hoistway, (5) is a car, (8) is a car lift detection device, (8a) is a car movement signal, (8b) is a rope, (12) is a hydraulic pump, and (13) is Electric motor, (14) rotary encoder (electric motor rotation detection means), (14a)
Is a pulse signal (rotation signal), (41) is a traveling pattern generating means, (41U) is an ascending traveling pattern generating circuit, (41D) is a descending traveling pattern generating circuit, (45) is a bias pattern generating circuit, and (47) is The second conversion circuit, (55) is the first conversion circuit, and (57) is the converter. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A traveling pattern generating means for generating a predetermined traveling pattern when an elevator is moved up and down, a bias pattern generating circuit for generating a bias pattern for correcting the traveling pattern of an electric motor according to an oil leakage amount of a hydraulic pump, and a car. And a car up-and-down detection device for continuously detecting the up-and-down motion of a car through a rope which is connected to the car and stretched along the hoistway and continuously generating a car movement signal when the car is moved up and down. A first conversion circuit that converts a car movement signal output from the car to a car speed in accordance with the signal level of the traveling pattern; a motor rotation detection unit that detects rotation of the electric motor and generates a rotation signal when rotating; A second conversion circuit for converting a rotation signal output from the electric motor rotation detection means into a rotation speed in accordance with a signal level of the traveling pattern; A converter for converting the rotation signal output from the rotation detection means into a rotation angle, and feedback of the car speed, the rotation speed, and the rotation angle by the first conversion circuit, the second conversion circuit, and the converter. A control device for a hydraulic elevator, wherein the control device is configured to perform