JPH02215676A - Control device for hydraulic elevator - Google Patents

Abstract

PURPOSE:To reduce space propagation of noise resulting from an induction motor and a hydraulic pump by arranging the hydraulic pump, the induction motor and a rotation detector in the oil of an oil tank. CONSTITUTION:A rotation detector 17 is formed of a pulse encoder which is magnetic-coupled. As a result, the rotation of an induction motor 7 can be digitally detected with ease in even oil of an oil tank 10. Also, a hydraulic pump 8, the induction motor 7 and the rotation detector 17 are submerged into the oil of the oil tank 10, thus reducing space propagation of noise resulting from the 7, 8 and 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a hydraulic elevator.

[Conventional technology] As a conventional control device for this kind of hydraulic elevator.

For example, the technique disclosed in Japanese Patent Application Laid-open No. 63-252885 can be mentioned.

FIG. 2 is a block diagram showing this conventional hydraulic control system.

In the figure, (1) is an elevator car, (2) is a hydraulic jack with a built-in plunger (3), (4) is a sheave attached to the top of the plunger (3), and (5) is a sheave (4). This robe (
Both ends of 5) are attached to the car (1) and the foundation (6), respectively. (7) is an AC induction motor directly connected to a hydraulic pump (8) that can rotate in reverse, and (9) is an electromagnetic switch for switching pressure oil placed between the hydraulic jack (2) and the hydraulic pump (8). The valve (1,0) is the oil tank.

(11) is a speed generator as a rotation detector attached to the induction motor (7), which detects the rotation of the induction motor (7) and transmits it to the speed control device (12). (R,
S, T) are three-phase AC power supplies, (13) are converters that convert three-phase AC to DC, (14) are smoothing capacitors, (
15) is an inverter that controls the pulse width of DC and converts it into three-phase AC with variable voltage and variable frequency. (16) is a regeneration inverter, which regenerates the DC obtained through the inverter (15) during regeneration of the induction motor (7) into the three-phase AC power source (R, , S, T).

The speed control device (12) includes a speed generator (
In addition to the detection signal from 11), a command signal from a command switch (not shown) is input manually, and a control signal (12a) is output to the inverter (15).

Next, the operation of the conventional hydraulic elevator control device configured as described above will be explained.

Now, from the command switch (not shown) to the speed control device (12
), the speed control device (12) reads out the speed reference data and compares this speed reference data with the rotation detection data from the speed generator (11) to reduce the deviation. The rotation of the induction motor (7) is controlled via the inverter (15). Further, the speed control device (12) operates according to the operating state of the induction motor (7).
The converter (13) and the regenerative inverter (15) are controlled to operate selectively. The induction motor (7) whose rotation is controlled in this manner controls the hydraulic pressure of the hydraulic jack (2) via the hydraulic pump (8).
The car (1) is raised and lowered.

[Problems to be Solved by the Invention] However, in this type of conventional hydraulic elevator control device, the induction motor (7) and the hydraulic pump (8) are installed in an exposed state in the atmosphere. Noise generated from the electric motor (7) and the hydraulic pump (8) may become space-borne sound and propagate to the outside.

In order to reduce such space-borne noise, induction motors (
7) and a method in which the hydraulic pump (8) is submerged in oil in an oil tank (10) (hereinafter simply referred to as "r-submerged method") have been proposed in the past. Furthermore, in order to improve the controllability of the induction motor (7), digital speed control has been introduced from the past, and for this digital control, an optical pulse encoder is used as a rotation detector of the induction motor (7). is commonly used.

However, the optical pulse encoder could not be used in the above-mentioned submerged method because of its poor light transmittance in oil.

Therefore, by adopting a submerged method, this invention reduces the spatially propagated noise generated from the induction motor and hydraulic pump (2).The rotation of the induction motor can be digitally detected, and the high-performance An object of the present invention is to provide a control device for a hydraulic elevator that can perform digital speed control.

[Means for Solving the Problems] A control device for a hydraulic elevator according to the present invention includes a hydraulic pump that supplies oil to a hydraulic jack, an induction motor connected to the hydraulic pump, and a rotation of the induction motor. and a control means for controlling the speed of the induction motor based on a rotation detection signal from the rotation detector, and the hydraulic pump, the induction motor, and the rotation detector are disposed in oil in an oil tank. In addition, the rotation detector is configured with a magnetically coupled pulse encoder.

[Operation 1] In the present invention, since the rotation detector is constituted by a magnetically coupled pulse encoder, the rotation of the induction motor can be easily digitally detected even in oil in an oil tank. Furthermore, since the hydraulic pump and induction motor are submerged in oil, the spatially propagated noise generated by them can be reduced.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a configuration diagram showing a control device for a hydraulic elevator according to an embodiment of the present invention. In addition, in the figure, the same reference numerals and the same / - symbols as in the conventional example of FIG. 2 indicate the same or corresponding parts as the conventional example described above.
Duplicate explanations will be omitted here.

In the figure, (17) is a rotation detector connected to the rotating shaft of the induction motor (7), which is magnetically coupled, for example.
This is a pulse encoder consisting of a pair of a rotating magnet and a reed switch, which is used as a rotation detector for automobile speedometers.It digitally detects the rotation of an induction motor (7) and uses the rotation detection signal as a control means. The speed control device (12) is operated manually. (18) is the oil tank (1
The induction motor (7), the hydraulic pump (8), and the pulse encoder (17) are submerged in this oil (18). (19) is the oil tank (
10) bottom and induction motor (7) and hydraulic pump (8)
It is a vibration-proof rubber inserted between the induction motor (7)
And vibrations of the hydraulic pump (8) are prevented from being directly transmitted to the oil tank (10).

Next, the hydraulic equipment of this embodiment configured as described above, 1
The operation of the Noveta control device will be explained.

When a start command is given to the speed control device (1゜2) from a command switch (not shown), the speed control device (12) reads speed reference data and converts this speed reference data and rotation detection data from the pulse encoder (17). Compare with 12,
The rotation of the induction motor (7) is digitally controlled via the inverter (15) to reduce the deviation. The speed control device (12) also controls the converter (13) and the regenerative inverter (1) according to the operating state of the induction motor (7).
, 5) are controlled to operate selectively.

So, the induction motor (7) whose rotation is controlled in this way
The hydraulic jack (2) is connected via the hydraulic pump (8).
The hydraulic pressure of the car (1) is controlled to raise and lower the car (1).

During this control operation, the rotation of the induction motor (7) is digitally detected by the magnetically coupled pulse encoder (17).
) is submerged in the oil (18) of the oil tank (10) together with the induction motor (7) and hydraulic pump (8), rotation detection can be easily and accurately performed, unlike an optical pulse encoder.

In addition, the induction motor (7) and hydraulic pump (8) are powered by oil (18).
), the noise generated from the induction motor (7) and hydraulic pump (8) will not be propagated to the outside as space-borne sound.

In this way, the control device for the hydraulic elevator according to the second embodiment has the hydraulic pump (8) that supplies oil to the hydraulic jack (2).
), and an induction motor (
7), a rotation detector (17) for detecting the rotation of the induction motor (7), and a control means for controlling the speed of the induction motor (7) based on a rotation detection signal from the rotation detector (17). A speed control device (12) as a hydraulic pump (8), an induction motor (7) and a rotation detector (
17) is disposed in the oil (18) of the oil tank (10), and the rotation detector (17) is magnetically coupled to a pulse encoder.

Therefore, according to the hydraulic elevator control device of this embodiment, unlike the conventional digital control method using a rotation detector and an optical pulse encoder at 12, the submerged method in which the hydraulic pump and induction motor are submerged in oil is used. There is no problem in adopting the submerged method, and the induction motor (7) and hydraulic pump (8) can be easily adopted.
) can reduce the spatially propagated sound generated by the noise.

In addition, regardless of the adoption of this submerged method, the induction motor (
7) rotation can be accurately detected digitally,
High performance digital speed control can be performed based on this rotation detection signal.

By the way, the magnetically coupled pulse encoder (17) of the embodiment described above has been explained based on the configuration of a rotation detector for an automobile speedometer. The reed switch is not limited to one that is magnetically coupled to the switch, and a magnetic sensor may be used instead of the reed switch.

[Effects of the Invention] As shown in E below, the hydraulic elevator control device of the present invention includes a hydraulic pump that supplies oil to a hydraulic jack, an induction motor connected to the hydraulic pump, and a rotation control device for the induction motor. the hydraulic pump, the induction motor, and the rotation detector are submerged in oil in an oil tank. In addition, since the rotation detector is configured with a magnetically coupled pulse encoder, by adopting the submerged method, it is possible to reduce the spatially propagated noise generated from the induction motor and hydraulic pump. In addition, regardless of whether this submerged method is adopted, the rotation of the induction motor can be digitally detected using a magnetic pulse encoder, and high-performance digital speed control can be performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a control device for a hydraulic elevator according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional control device for a hydraulic elevator. In the figure, 2: Hydraulic jack 7: Induction motor 8: Hydraulic pump 10: Oil tank 12: Speed control device (control means) 17: Pulse encoder (rotation detector) 18: Oil. In the drawings, the same arrows and the same symbols indicate the same or equivalent parts. Agent: Patent attorney Daikan Masuo (2 rows)

Claims (1)

[Claims] (1) A hydraulic pump that supplies oil to the hydraulic jack, an induction motor connected to the hydraulic pump, a rotation detector that detects rotation of the induction motor, and a rotation detection signal from the rotation detector. and control means for controlling the speed of the induction motor, the hydraulic pump, the induction motor, and the rotation detector are disposed in oil in an oil tank, and the rotation detector is configured with a magnetically coupled pulse encoder. A hydraulic elevator control device characterized by: