JPH04213576A - Drive control device for hydraulic elevator - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a shock due to startup and a vibration related thereto by quickly making pump pressure equal to jack pressure in the hydraulic elevator drive control device where a hydraulic pump is driven by a variable speed control electric motor for feeding pressure oil to a hydraulic jack, and an elevator cage is thereby caused to travel. CONSTITUTION:When a hydraulic elevator is operated, a compensation torque instruction value is inputted to a torque controller 29 for correcting differential pressure between a hydraulic jack and a pump. Concurrently, a signal then outputted from a speed detector 15 is inputted to a speed controller 27 as a speed instruction value, thereby nullifying the output of the speed controller 27 for controlling an induction motor 14. According to the aforesaid construction, hydraulic jack pressure can be made equal to pump pressure, thereby eliminating a startup shock and a vibration related thereto.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] This invention relates to a drive control device for a hydraulic elevator, and more particularly to a drive control system for a hydraulic elevator in which a variable speed controlled electric motor drives a hydraulic pump to send pressurized oil to a jack to drive a car. This relates to a control device.

0002

[Prior Art] A conventional hydraulic elevator rotates an electric motor at a constant speed during upward operation, and uses a flow control valve to adjust the amount of oil sent to the hydraulic jack out of the fixed amount of oil discharged from the hydraulic pump. By doing so, and during descending operation, the speed of each car is controlled by adjusting the amount of oil that flows back from the hydraulic jack to the tank using the weight of the car using a flow control valve. In this system, during upward operation, excess oil is returned from the hydraulic pump to the tank, resulting in a large loss of energy, and during downward operation, potential energy is converted to heat, resulting in a large rise in oil temperature. In contrast,
Recently, a method has been proposed in which the discharge amount of a pump driven by the induction motor is variably controlled by subjecting the induction motor to variable voltage variable frequency control (hereinafter referred to as VVVF control) using an inverter or the like. With this method, only the required amount of oil is sent to the hydraulic jack according to the speed command value during upward operation, and the electric motor is regeneratively braked using the amount of oil returned to the tank during downward operation, resulting in low energy consumption and low oil temperature rise. A highly efficient hydraulic elevator can be obtained. By the way, in this VVVF control hydraulic elevator, the solenoid valve that opens and closes the pressure oil flow path may be a simple one that simply opens and closes, but the solenoid valve may be opened at the same time as the induction motor is rotated when the elevator is started. Then, because the pressure on the pump side is lower than the pressure on the jack side, the car lowers, causing a large starting shock and vibration. On the other hand, it has been considered to provide a bias pattern as a speed command value that makes the pressure on the pump side equal to the pressure on the jack side, as disclosed in Japanese Patent Publication No. 64-311, for example. That is, as shown in FIG. 3, a car running pattern signal is given in a form that is superimposed on a bias pattern signal, and this superimposed pattern signal is used as a speed command value to control the electric motor and make the car run, thereby generating a starting shock. It is intended to suppress the Also,
As shown in Fig. 4, a pressure sensor is provided to detect the jack side pressure and the pump side pressure, and the differential pressure is fed back to the speed controller to control the electric motor and equalize the jack side pressure and the pump side pressure. A method has also been proposed. That is, FIG. 4 is a configuration diagram showing a conventional drive control device for a hydraulic elevator. In the figure, (1) is a cylinder buried in the pit of the hoistway, (2) is the pressure oil filled in this cylinder (1), and (3) is the plunger supported by this pressure oil (2). (1) to (3) constitute a hydraulic jack. (4) is a deflection wheel attached to the top of the plunger (3), (5) is a rope fixed to the pit and hung from the deflection wheel (4), (6) is a rope (5)
The cage attached to the other end (7) always functions as a check valve and is switched when the electromagnetic coil is energized to conduct in the opposite direction, and (8) is the cylinder (1). The pipe (9) is reversibly operated and is connected between the electromagnetic switching valve (7) and the electromagnetic switching valve (7) to send and receive pressure oil. pump, (11
) is oil, and (12) is an oil tank storing oil (11), which sends and receives oil to and from the hydraulic pump (9) via a pipe (13). (14) is the 3 that drives this hydraulic pump (9).
A phase induction motor provides torque to the hydraulic pump (9). (15) is a speed detector that detects the rotation speed of the induction motor (14), and outputs a voltage proportional to the rotation speed of the induction motor (14). (16) is a jack-side pressure sensor for detecting the pressure inside the pipe (8), (17) is a pump-side pressure sensor for detecting the pressure inside the pipe (10), and (18) is a three-phase AC power supply. , (19) is a converter for converting three-phase AC into DC, (20) is a smoothing capacitor for smoothing the output of converter (19), (21) is a regenerative resistor for consuming regenerative power, ( 22) is a regenerative transistor that conducts when in a regenerative state, and (23) is an induction motor (
(14) is a PI controller to which the outputs of the sensors (16) and (17) are supplied;
25) is an adder that adds the output of the PI controller (24) and the car speed pattern command (26), and (27) is an adder (2
5) and a speed controller (15), (28) is a current detector for detecting the input current of the induction motor (14), and (29) is a current detector ( 2
8), a torque controller that controls the inverter (23) according to each output of the speed detector (15) and speed controller (27).

0003

[Problem to be Solved by the Invention] In this method of increasing the pump side pressure using the bias pattern signal, the bias pattern signal value at which the jack side pressure and the pump side pressure become equal varies depending on the load, oil temperature, etc. The disadvantages are that the dead time of the pump differs each time, and that it basically takes a long time for the pressure on the pump side to become equal to the pressure on the jack side.

[0004] Furthermore, the method of detecting the jack side pressure and the pump side pressure and feeding back the deviation has to be fed back to the input side of the speed controller, which results in a lack of quick response due to the delay of the speed controller. There were drawbacks. It is also possible to shorten the time until pressure balance by adding a compensation torque to compensate for the pressure difference between the pump side pressure and the jack side pressure to the input of the torque controller, but in this case, the speed command is not given. There was a problem in that the speed controller would give a command to the torque controller to stop the motor because the motor would rotate even when the motor was not running.

[0005] This invention was made to solve the above-mentioned problems, and it is possible to quickly equalize the pump side pressure with the jack side pressure, thereby preventing starting shock and accompanying vibrations. The purpose is to obtain an elevator drive control device.

[0006]

[Means for Solving the Problems] A drive control device for a hydraulic elevator according to a first aspect of the present invention inputs a compensation torque command value to a torque controller to compensate for a pressure difference between a jack side pressure and a pump side pressure at the time of startup. At the same time, the output of the speed detector at this time is added as a speed command value to the input of the speed controller, and the output of the speed controller is set to zero, thereby controlling the induction motor to reduce the jack side pressure and the pump side pressure. It is designed to equalize the pressure.

A drive control device for a hydraulic elevator according to a second aspect of the invention includes a pressure controller that calculates a torque command value for an electric motor in response to a deviation between an output of a jack pressure detector and an output of a pump pressure detector at the time of startup. and a pressure balance speed command calculator that calculates a command value for the speed controller based on this torque command value, and controls the electric motor to equalize the jack side pressure and the pump side pressure.

[0008]

[Operation] In the first aspect of the invention, immediate response during pressure balance is obtained by adding a compensating torque to the input of the torque controller to compensate for the differential pressure between the pump side pressure and the jack side pressure. Also, by adding the output of the speed detector at this time to the input of the speed controller as a speed command value, the operation of the speed controller is disabled.

In the second invention, the pump side pressure and the jack side pressure are detected, and the pressure controller calculates a pressure balance torque command from the deviation, and adds it to the input of the torque controller to adjust the pressure balance torque command. Gain responsiveness. or,
From the pressure balance torque command, a pressure balance speed command is calculated by a pressure balance speed command calculator that has a transfer relationship inverse to the transfer function of the speed controller, and is added as a speed command value to the input of the speed controller, thereby controlling the speed. By nullifying the DC component of the input to the controller and making the input only the AC component, the speed controller operates as a differential feedback device with respect to pressure.
Stabilize the pressure control system.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of the present invention,
1 to 29 are the same as described above. In this embodiment, an adder 30 is provided between the speed controller 27 and the torque controller 29, the output of the speed controller 27 is supplied to one input terminal of the adder 30, and the PI controller is supplied to the other input terminal. The output of the adder 30 is supplied to the torque controller 29. Further, the output of the speed detector 15 is supplied to the other input terminal of the adder 25.

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be explained. Now, if there is a call for car 6, the values of the jack-side pressure sensor 16 and the pump-side pressure sensor 17 are input to the PI controller 24. The output is then input to the torque controller 29 via the adder 30. The torque controller 29 drives an inverter 23 based on the output of the PI controller (24), the output of the speed detector 15, and the output of the current detector 28, and the inverter 23 drives the induction motor 14. And PI controller 2
4 is a jack side pressure sensor 16 and a pump side pressure sensor 1
The value input to the torque controller 29 is automatically adjusted so as to make the output deviation of No. 7 zero. At this time, the induction motor 14 rotates, but by giving the output of the speed detector 15 as a speed command value to the speed controller 27, the deviation between the speed command value and the output of the speed detector 15 becomes zero, so that the speed cannot be controlled. Vessel 2
7 does not act to stop the induction motor 14. In this way, the jack side pressure and the pump side pressure become equal. After the pressures are equalized, the electromagnetic switching valve 7 is opened. At this time, the jack side pressure and the pump side pressure are equal, so the hydraulic jack does not move. Naturally, car 6 doesn't move either. Then, the induction motor 14 is driven according to the car speed pattern command 26 to move the car 6 up and down. At this time, the PI controller 24 is not operated, and the output value when the pressure is balanced and the output value of the speed detector 15 are memorized, and the values are input to the torque controller 29 and the speed controller 27, respectively. Ru. Furthermore, if the PI controller 24 is operated when the electromagnetic switching valve 7 is closed, it becomes possible to immediately move the car using the relevel pattern signal even during relevel operation, for example. Also, here we have explained how to detect and feed back the jack side pressure and pump side pressure in order to obtain compensation torque to balance the pressure, but it is also possible to detect the load inside the car and give compensation torque according to that load. You can do it like this.

FIG. 2 is a block diagram showing another embodiment of the present invention, and numerals 1 to 30 are the same as those described above. In this embodiment, the jack side pressure sensor 16 and the pump side pressure sensor 1
A pressure controller 31 is provided which calculates a torque command value for the electric motor in response to the output deviation of 7, and this output is applied to an adder 30 and a pressure balance speed command calculator 33. or,
An adder 32 is provided between the pressure balance speed command calculator 33, the car speed pattern command 26, and the speed controller 27, and supplies the output of the pressure controller 31 to the pressure balance speed command calculator 33. Then, the car speed pattern command 26 is supplied to one input terminal of the adder 32, the output of the pressure balance speed command calculator 33 is supplied to the other input terminal, and the output of the adder 32 is supplied to the speed controller 27. I'll do what I do.

Next, the operation of another embodiment of the invention shown in FIG. 2 will be explained. Now, if there is a call for car 6, the values of the jack-side pressure sensor 16 and the pump-side pressure sensor 17 are input to the pressure controller 31. The output is then input to the torque controller 29 via the adder 30. The torque controller 29 drives an inverter 23 based on the output of the pressure controller 31, the speed detector 15, and the current detector 28, and the inverter 23 drives the induction motor 14. And the pressure controller 31
are the jack side pressure sensor 16 and the pump side pressure sensor 17
The pressure balance torque command input to the torque controller 29 is automatically adjusted so as to make the output deviation of the torque controller 29 zero. At this time, the induction motor 14 rotates, but the pressure balance torque command is input to the pressure balance speed command calculator 33, and the pressure balance speed command calculator 33 automatically calculates a speed command value commensurate with the pressure balance torque command. , speed controller 27
, the DC component of the deviation between the speed command value and the output of the speed detector 15 becomes almost zero, so the speed controller 27 does not act to stop the induction motor 14. Moreover, since the pressure is expressed as the integral of the flow rate of pressure oil, and the flow rate is proportional to the rotational speed of the pump, the output of the speed detector 15 corresponds to the differential value of the output of the pump-side pressure sensor 17. now,
Since the DC component of the input to the speed controller 27 is removed, only the ripple component is input. The ripple component of the output of the speed detector 15 corresponds to the differential value of the ripple component of the output of the pump-side pressure sensor 17, and the differential value is fed back to the pressure by the operation of the speed controller 27. . Therefore, pressure ripple can be suppressed. As a result, the jack side pressure and the pump side pressure become stably equal. After the pressures are equalized, the electromagnetic switching valve 7 is opened. At this time, the jack side pressure and the pump side pressure are equal, so the hydraulic jack does not move. Naturally, car 6 doesn't move either. Then, the induction motor 14 is driven according to the car speed pattern command 26 to move the car 6 up and down. At this time, the pressure controller 31 is made not to operate, and the pressure balance torque command when the pressure is balanced and the output value of the pressure balance speed command calculator 33 at that time are stored, and the values are stored in the torque controller 29, It is input to the speed controller 27. Furthermore, if the PI controller 24 is operated when the electromagnetic switching valve 7 is closed, it becomes possible to immediately move the car using the relevel pattern signal even during relevel operation, for example.

[0014]

As described above, according to the first invention, a compensation torque command value for compensating for the differential pressure between the jack side pressure and the pump side pressure is applied to the input of the torque controller at the time of startup, and at the same time speed control is performed. By adding the output of the speed detector at this time as a speed command value to the input of the controller and setting the output of the speed controller to zero, the induction motor is controlled to equalize the jack side pressure and the pump side pressure. Therefore, the pressure on the pump side can be immediately equalized with the pressure on the jack side, and then the electromagnetic switching valve is opened to raise and lower the car. This enables drive control of hydraulic elevators that prevents startup shock and associated vibrations. There is an effect that the device can obtain.

According to the second invention, the pressure controller detects the jack side pressure and the pump side pressure at startup and calculates the torque command value of the induction motor in response to the deviation between the jack side pressure and the pump side pressure. At the same time, a compensation torque command value for compensating for the side pressure difference is added to the input of the torque controller.
A pressure balance speed command calculator is used to calculate the command value of the speed controller based on this torque command value, and the input of the speed controller is made only for the ripple, so that the speed controller operates as a differential feedback device with respect to pressure. By controlling the induction motor to equalize the jack side pressure and the pump side pressure, the pump side pressure can be quickly and stably made equal to the jack side pressure, and then the solenoid switching valve can be turned on. Since the opening car is raised and lowered, there is an effect that a drive control device for a hydraulic elevator can be obtained that can prevent starting shock and accompanying vibrations.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the invention.

FIG. 3 is a diagram showing a motor speed command of a conventional VVVF control hydraulic elevator.

FIG. 4 is a configuration diagram showing a conventional hydraulic elevator drive control device.

[Explanation of symbols]

1 Cylinder 2 Pressure oil 3 Plunger 7 Solenoid switching valve 9 Hydraulic pump 14 Induction motor 15 Speed detector 23 Inverter 27 Speed controller 28 Current detector 29 Torque controller 31 Pressure controller

Claims (2)

[Claims] Claim 1: A solenoid valve capable of blocking the flow of pressure oil, a speed detector that detects the speed of an induction motor, a current detector that detects the primary current of the induction motor, and a speed command value and a speed detector. a speed controller that calculates a torque command value from the deviation of the output of the speed controller, and a torque controller that controls the inverter based on the output of the speed controller, the output of the speed detector, and the output of the current detector. In a hydraulic elevator that controls the operating speed of a hydraulic jack by variable-speed driving a hydraulic pump connected to the induction motor, a compensation torque command is used to compensate for the differential pressure between jack side pressure and pump side pressure at startup. The induction motor A drive control device for a hydraulic elevator, characterized in that the pressure on the jack side and the pressure on the pump side are made equal by controlling the above. 2. A solenoid valve capable of blocking the flow of pressure oil, a speed detector for detecting the speed of an induction motor, a current detector for detecting the primary current of the induction motor, and a speed command value and a speed detector. a speed controller that calculates a torque command value from the deviation of the output of the speed controller, and a torque controller that controls the inverter based on the output of the speed controller, the output of the speed detector, and the output of the current detector. In a hydraulic elevator that controls the operating speed of a hydraulic jack by variable-speed driving a hydraulic pump connected to the induction motor, the torque command of the electric motor is generated in response to a deviation between the jack side pressure and the pump side pressure at startup. a pressure controller that calculates a value, and a pressure balance speed command calculator that calculates a command value of the speed controller based on the torque command value, and a pressure balance speed command calculator that calculates a command value of the speed controller based on the torque command value. In addition to the input, the command value of the pressure balance speed command calculator is added to the input of the speed controller, thereby controlling the electric motor to equalize the jack side pressure and the pump side pressure. Hydraulic elevator drive control device.