JPH0367875A - Hydraulic elevator control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control device for a hydraulic elevator, and more specifically, the present invention relates to a control device for a hydraulic elevator, and more specifically, it is a control device for controlling a hydraulic elevator. The present invention relates to a control device for a hydraulic elevator that prevents startup delays and startup shocks that occur during startup.

[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 rate when ascending, returns a fixed amount of oil from the hydraulic pump to the tank, and when a start command is issued, the flow rate control valve adjusts the amount returned to the tank. The descending samurai controls the speed of the car by adjusting the descent of the car due to its own weight using a flow control valve. This method not only circulates excess oil when ascending, but also consumes potential energy to heat the oil during descending, resulting in large energy loss and a significant rise in oil 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 the discharge amount of the pump itself is made variable by a control device, and the structures of the control device and the pump are 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 has been considered in which the rotation speed of an induction motor is controlled over a wide range by changing the voltage and frequency.This method is called the motor rotation speed control method, in which a constant discharge pump is used and the discharge amount of the pump is controlled by the motor. It is controlled variably by changing the rotation speed of the motor, and 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. 3, 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 n1 is exceeded, 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, reaches a constant speed of 1, starts decelerating at time tl3, and reaches time tl
Stop at 4. After that, the hydraulic pump stops at time tl5. 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.

This invention was made to solve the above-mentioned problems, and when the car is stopped, it can be stopped at a predetermined position with smooth movement, and even if the stopping position is shifted due to leakage of the hydraulic pump, etc. It is an object of the present invention to provide a control device for a hydraulic elevator that does not cause a delay in the operation of the car at startup or a startup shock by immediately correcting this deviation and always stopping the car at a predetermined position.

[Means for Solving the Problems] A control device for a hydraulic elevator according to the present invention includes a first pattern generating means for controlling the rotational 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 is installed in the pipeline between the jack and the hydraulic pump that is connected to the rotation of the electric motor, and outputs a speed signal in a low speed pattern to maintain or correct the stop position before and after the car stops. and second pattern generating means for controlling the rotation speed of the electric motor, and the normally closed solenoid valve is configured to be energized when each of the speed signals is output, and to open the valve. .

[Function] When the load on the car changes due to a change in the number of passengers, the second pattern generating means in the present invention detects this and detects the shift in the stopping position of the car due to the change in load using a speed signal of a low speed pattern. Controls the electric motor to maintain a predetermined stopping position. In addition, if the car deviates from a predetermined stopping position due to leakage of the hydraulic pump due to the car being stopped for a long period of time, it is corrected by outputting a speed signal of a low speed pattern in the same manner as described above.

[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 supported by this pressure oil (3), (5) is a cage placed on the top of plunger (4), (5a) is a cage floor, and (7) is a cage (5). ), (9) is a deceleration command switch for decelerating the moving car (5), and (10> is a stop command switch for stopping the car (5)).

(11) always functions as a check valve, and the electromagnetic coil (ll
(lla) is an electromagnetic switching valve that is switched when cylinder (b) is turned on and conducts in the opposite direction;
) and the electromagnetic switching valve (11) to supply pressure oil, (I8) is a pressure sensor that detects the pressure of this oil pipe (lla), and (6a) is a pressure sensor (6 ) is the output signal of (12) rotates reversibly, and the tubes (1, 2a)
A hydraulic pump that sends and receives pressure oil to and from the electromagnetic switching valve ((1), (8) is a pressure sensor that detects the pressure in the pipe (12a), and (8a) is the output of this pressure sensor (8). signal,
13) is a three-phase induction motor (hereinafter referred to as the motor) that drives the hydraulic pump (12), and (1, 4) is this motor (
13) is a speed generator that detects the rotation speed, (15> is a tube (
(16) is an oil temperature detection device that detects the oil temperature of the oil tank (I5).

R, S, and T are three-phase AC power supplies, (21) is a rectifier circuit that exchanges three-phase AC into DC, (22) is a capacitor that smoothes this DC, and (23) is a variable voltage that controls the pulse width of DC. , an inverter that generates variable frequency three-phase alternating current, (2
5) is the pressure sensor (6), (8) signal <6a> (8a
), the speed signal (14a) of the speed generator (14), the oil temperature signal (16a) of the oil temperature detection device (1st motor), and the normal signal that is closed from when a start command is issued until a stop command is issued. Open contact (3
(16) The operation signal (3[)da) generated by
The speed control device receives a signal (38a) to be described later, a stop signal (10a) from a stop command switch <10>, etc., and outputs a signal (25a) to control the inverter (23).

(31) is a relay that is excited when a motor pattern signal (46a), which will be described later, is output, and when there is a drive command to the inverter (23), it closes the normally open contacts (31a) to (31c), and the motor (13) closes the normally open contacts (31a) to (31c). Connect 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, <38a) is a signal that is output when the car (5) stops due to a call at the landing or when the door is opened or closed, and (39) is a signal that is output when there is a passenger in car 5). The load judgment circuit (43) outputs the signals of the pressure sensors (13) and (8) (
8a), (8a), (38a) and operation signal (3
0da) outputs a signal (43a) when manually operated, (41,0), (41,D) outputs a signal when the normally open contact (3[1d) is closed, and the car (5)
This is a pattern generation circuit that instructs the activation of a pattern that causes the vehicle to run.

(41υ> is an upward traveling pattern generation circuit, and when the deceleration command signal (9a) is input, the output decreases, and once it reaches a constant low speed, the pattern becomes zero by the stop signal (10a), and the car (5) Further, (41D) is a descending traveling pattern generating circuit, which operates in a symmetrical manner with the ascending traveling pattern generating circuit (41, U) described above.

(41LIR), (41DR) This signal is output when the elevator car floor does not match the landing floor.
? ), (4, IDR) to generate a rising and falling running pattern generation circuit (41U).

The maximum value of the pattern (41D) is lowered to a value corresponding to the floor shift, and a car speed command is output. (41, LIa)
is an upward contact that remains closed during two-way operation during traveling and floor alignment, (4), Da) is a downward contact,
(42) is a changeover switch where the load side pressure signal (6a) and the pump discharge pressure signal (8a) are input, and when the signal (8a) becomes larger than the signal (6a), the signal (42a) becomes "L". , (45) is a low rotation pattern generation circuit that generates a predetermined low rotation pattern when the signal (43a) from the car hold command circuit <43> becomes "H", and the signal (42a) of the changeover switch (42) When manually applied, it maintains a constant value.

(40) is a delay circuit, (46) is an adder, (46a) is a pattern signal, and when this pattern signal (48a) is output, the electromagnetic coil (11, b) and relay (31) are excited.

(47) converts the speed signal (1, 4a) into the pattern signal (48
A conversion circuit that converts the level to the same voltage level as a), (4
8> 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 outputs a linear voltage command signal (5z) for a frequency command signal. This is a reference sine wave generation circuit that outputs a signal (25a) 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).

In the pressure elevator control device according to the present invention configured as described above, 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. is output, the normally open contact (30d) is closed, and the signal (43a) from the car hold command circuit (43) is output, so the low rotation pattern signal generation circuit (43) according to the load is output.
When the signal (45a) is output from 5) and the pattern (46a) is output from the adder (46), the electromagnetic switching valve (11
) and relay (31> are energized and normally open contact (81a)
~(31e) is closed, and the electric motor (13) is connected to the inverter (23). Also, a signal is output from the delay circuit (40) after a predetermined time from the operation signal (30da), a travel pattern signal is output from the upward travel pattern generation circuit (4111), and the oil is sent to the oil tank (15), pipe <15a). ,
Hydraulic pump (12), pipe (12a), electromagnetic switching valve (1)
1) and the pipe (lla) into the cylinder (2>), and the car (5) is raised by an amount corresponding to the amount of oil.
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 travel pattern generation circuit (410) gradually decreases until it outputs a constant value. Then, the car (5) continues to rise at a very slow speed, and stops when a stop command signal (10a) is output.

Furthermore, in the descending operation of the car (5), the car speed slam is symmetrical to the above-mentioned increase, so the electric motor (13) controls the descending operation of the car (5) while braking in reverse. 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.

After the car (5) has stopped, the above-mentioned signal (38a) is output, for example, when a passenger gets on or off, or when the door is open, or when there is a call from the landing.
Since the signal (43a) from the holding command circuit (43) is in the "H" state, the low rotation signal (43a) to the electric motor (13) is
5a) continues to output even after the car (5) has stopped. In this case, when the car load changes due to passengers getting on and off, the oil pressure in the cylinder (3) 1 changes via the plunger (4), so the leakage of the hydraulic pump (12) also changes, which holds the car (5) in place. The situation will be different.

For this reason, for example, the load side pressure signal (
When 6a> becomes smaller than the pump discharge pressure signal (8a>), the pressure on the hydraulic pump (12) side is high, so if this state remains, the car (5>) will be pushed up.

In this way, when the load side pressure signal (6a) mentioned above becomes smaller than the pump discharge pressure signal (8a), the changeover switch (
A signal (42a) from 42> is output and input to the low rotation pattern generation circuit (45>), and this output signal (45a) balances the load on the car (5>) and the corresponding discharge pressure of the pump (12). The electric motor (13) is driven at a low rotation speed so that when the difference between the load side pressure signal (6a) and the pump discharge pressure signal (8a) reaches a predetermined value, the car (5) is driven at a constant low rotation speed. ) is stopped.

In addition, when the car (5) completes door closing and moves to the next floor with a passenger on board, the normally open contact (
30d) is closed, the low rotation pattern generation circuit (45) outputs the low rotation pattern signal (45a)2 to keep the car (5) in a stopped state.

When there are no passengers in the car (5) and the car (5) completes closing the door at the normal position and stops, the signal (43a) from the holding command circuit (43) will no longer be output. Signal (45) from low rotation pattern generation circuit (45)
a) becomes zero, and since the upper contact (41Ua) and the lower contact (41Da) are open, the pattern signal (46a) also becomes zero, and the relay (31> and electromagnetic switching valve (11) are no longer energized. When the car (5) is released, the operating pressure is maintained by closing the oil pipe by the electromagnetic switching valve (11), which functions as a check valve.

If the car (5>) remains in standby mode for a long time and the car (5> moves downward due to an oil leak, etc.) and the cam (7> activates the deceleration command switch (9) in the hoistway, The deceleration command signal (9a) is output, and the upward travel pattern generation circuit (41U) outputs a low rotation pattern signal through the closed upward contact (41Da), and on the other hand, the car floor and the landing floor no longer match. Therefore, the floor alignment command signal (41UR
) manually outputs a low rotation pattern signal, and the combination of these low rotation pattern signals gives a predetermined rotation speed to the electric motor (13), which simultaneously drives the hydraulic pump <
12>, the car (5) is moved through the electromagnetic switching valve 11), which is energized and in an open state, and the floors are aligned.

[Effects of the Invention] According to the present invention, a speed signal with a low rotation pattern is output according to specific conditions before and after the car is stopped, and this signal is used to control changes in the car load or the hydraulic pump. In order to deal with leakage, the motor is configured to control the rotation speed, so even if there is a temporary shift in the car position, it can be corrected immediately [7] and the car can be held in a predetermined position. This has the effect of providing a hydraulic elevator that does not have a delay in the car's operation at the time of startup or a startup shock.

[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 Figs. FIG. 4 is a diagram for explaining the operation when stopped. In the figure, (3) is jack, (5) is basket, (11
) is a solenoid switching valve (normally closed solenoid valve), (lla), (1
2a) is a pipe, (12> is a hydraulic pump, (13) is an electric motor, (41,, U) is an upward running pattern generation circuit, (41)
D) is a downward running pattern generation circuit, (42) is a changeover switch, and (45) is a low rotation pattern generation circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] a first pattern generating means for controlling the rotational speed of the electric motor by outputting a speed signal according to a predetermined pattern when the elevator goes up and down; a hydraulic pump that is driven in connection with the rotation of the electric motor; A second pattern generating means for controlling the rotational speed of the electric motor by outputting a speed signal of a low speed pattern in order to maintain or correct the stop position of the car, and installed in a conduit between the hydraulic pump and the jack. and a normally closed solenoid valve that is energized when each of the speed signals is output.