JPH10101277A - Hydralic elevator device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety by mounting an exclusive circuit, in particular, using at low speed operation and low speed descending movement such as releveling and inching operation separately from a main control circuit for lifting cage by switching a main control valve. SOLUTION: A solenoid valve 32, a pilot operation check valve 33, a specific low speed descending operation exclusive circuit with a throttle 34 are mounted separately from a main control valve 31 and the main control valve 31 is not used at the specific low speed descending operation and the specific low speed descending operation exclusive circuit which has small flow rate of actuation oil is used. Whereby, when abnormality causes in the solenoid valve 32 in the specific low speed descending operating, abnormal descending of a cage 2 is reduced to minimum. When power failure causes while the specific low speed descending operation, free run may not cause and abnormality of the cage 2 is rapidly blocked. As the pilot operation valve 33 is used, it is not limited to this, and that like operation can do such as a pressure control valve may be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic elevator, and more particularly to a hydraulic elevator in which a motor is controlled by inverter control or the like to control a discharge amount of a hydraulic pump driven by the motor.

[0002]

2. Description of the Related Art An example of a conventional hydraulic elevator will be described with reference to FIG. In the figure, 1 is a hydraulic jack for raising and lowering the car 2, 30 is a control unit for driving the hydraulic pump 5 by controlling the electric motor 4, 6 is a tank, 31 is a main control valve, and 31a is a solenoid coil.

When the car 2 is raised, the rotation of the hydraulic pump 5 is controlled, hydraulic oil is supplied to the hydraulic jack 1 through the main control valve 31, and the car 2 is raised. When the car 2 descends, the solenoid coil 31a is excited to fully open the main control valve 31, the rotation of the hydraulic pump 5 is controlled, and the hydraulic oil is discharged from the hydraulic jack 1 through the main control valve 31; The car 2 is lowered.

In the case of the hydraulic elevator of FIG. 3, if a power failure occurs while the car 2 is moving down at a low speed,
Car 2 may cause a free run. This is because the main control valve 31 is fully opened and the hydraulic pump 5 is controlled to control the flow rate of the hydraulic oil during the descent operation. For this reason, if a power failure occurs during the low-speed descent operation, the motor 4 stops, and the main control valve 31 is fully opened, so that the flow rate of the hydraulic oil rapidly increases, and the car 2 enters a free-run state. As the main control valve 31 closes, the car 2 decelerates, and when the main control valve 31 closes, the car 2 stops.

As a prior art for preventing this free running, there is Japanese Patent Application No. 8-160902. In this prior art, the opening degree of the main control valve is automatically changed depending on the oil pressure in each oil chamber constituting the main control valve and the flow rate and direction of the working oil flowing in the main control valve. This prior art will be described with reference to FIG. FIG. 4 is a schematic diagram showing the entire configuration of the hydraulic elevator, and the same reference numerals as those in FIG. 3 indicate the same components.

In the figure, reference numeral 7 denotes a main control valve, and a valve body 7
a, a jack-side oil chamber 7b connected to the hydraulic jack 1 by a hydraulic pipe, a pump-side oil chamber 7c connected to the hydraulic pump 5, a back-side oil chamber 7d arranged on the back side of the valve body 7a,
And a compression spring 7e.

Reference numeral 8 denotes a jack-side oil chamber 7b and a rear-side oil chamber 7d.
An electromagnetic pilot valve disposed between them, 8a and 8b are solenoid coils, 9 is an electromagnetic pilot valve connected to the pump side oil chamber 7c via a check valve 10 and the other is connected to the back side oil chamber 7d, and 9a is a solenoid coil , 11 are throttles arranged in parallel with the electromagnetic pilot valve 8, and 3 is a control unit for controlling the electric motor 4 and each of the solenoid coils 8a to 9a.

Next, the operation of the prior art will be described. First, the case of ascending operation will be described. In response to a command from the control unit 3, the electric motor 4 starts rotating in the ascending operation direction.
The hydraulic pump 5 connected thereto is driven to increase the pressure in the oil chamber 7c. Further, the solenoid coil 8b is excited to open the electromagnetic pilot valve 8, and equalize the pressures of the oil chambers 7b and 7d. Therefore, when the valve opening force due to the pressure in the oil chambers 7c and 7b exceeds the pressure in the oil chamber 7d and the valve closing force due to the spring 7e, the valve element 7a starts to open and the car 2 starts to rise.

The flow rate of the working oil flowing through the main control valve 7 increases with an increase in the rotation speed of the electric motor 4, and the opening degree of the main control valve 7 (the opening of the valve body 7a) increases with the increase in the flow rate. The movement amount) increases, and the car 2 accelerates. When the car 2 runs at the rated speed and reaches the deceleration start point of the destination floor, the rotation speed of the electric motor 4 starts to decrease, the flow rate of the hydraulic oil in the main control valve 7 decreases, and the The opening decreases. Therefore, when the car 2 starts decelerating and lands on the destination floor, the flow rate of the hydraulic oil in the main control valve 7 becomes zero, the main control valve 7 closes, and the electric motor 4 stops. The electromagnetic pilot valve 8 keeps its position until the solenoid coil 8a is excited.

As described above, during the ascending operation, the main control valve 7
Is increased or decreased in accordance with the flow rate of the working oil, so that the opening of the main control valve 7 is minimized. Therefore, even if a power failure occurs during the ascending operation, the main control valve 7 closes promptly as the flow rate of the hydraulic oil in the main control valve 7 becomes zero, so that the hydraulic oil flows backward and the car 2 Never free-run.

Next, the case of the descending operation will be described. Control unit 3
, The motor 4 first rotates in the ascending operation direction to prevent the start-up shock of the car 2, and the oil chamber 7 c
And the pressure in the pipe connected to the oil chamber 7c is increased to a predetermined pressure. Then, the solenoid coils 8a and 9a are excited, and the electric motor 4 is rotated in the descending operation direction. As a result, the pressure in the oil chambers 7c and 7d starts to decrease, and the oil chamber 7c
When the valve opening force due to the pressure in the oil chamber 7b exceeds the pressure in the oil chamber 7d and the valve closing force due to the spring 7e, the valve element 7a starts to open,
Car 2 starts descending.

When the main control valve 7 starts to open, the hydraulic oil in the hydraulic jack 1 is pushed out by the weight of the car 2 and is discharged from the hydraulic pump 5 to the tank 6 through the main control valve 7. The opening of the main control valve 7 also increases with an increase in the flow rate of the working oil in the main control valve 7. At this time, the electric motor 4 drives the hydraulic pump 5 according to a signal from the control unit 3 to control the flow rate of the hydraulic oil to accelerate the lowering of the car 2.

When the car 2 travels at the rated speed and reaches the deceleration start point on the destination floor, the rotation speed of the motor 4 starts to decrease,
The flow rate of the working oil in the main control valve 7 decreases, and the opening degree of the main control valve 7 decreases. Therefore, when the car 2 starts to decelerate and lands on the destination floor, the flow rate of the hydraulic oil in the main control valve 7 becomes zero, the main control valve 7 closes, the electric motor 4 stops, and the solenoid coil 8a and 9a are de-energized. As described above, even during the lowering operation, the opening of the main control valve 7 increases and decreases in accordance with the flow rate of the working oil, and is the minimum necessary opening.

If a power failure occurs during the descent operation, the solenoid coil 9a is de-energized, the electromagnetic pilot valve 9 is closed, and the operating oil in the oil chamber 7b is supplied to the oil chamber 7d through the throttle 11. Therefore, the valve element 7a moves in the closing direction, and the main control valve 7 closes. At this time, since the hydraulic oil supplied to the oil chamber 7d passes through the throttle 11, the main control valve 7 closes slowly. Therefore, a large shock is not applied to the car 2. Thus, the car 2 does not run free even during the descent operation.

[0015]

In the prior art shown in FIG. 3, even when the solenoid coil 31a is de-energized due to breakage of the spring or foreign matter in the hydraulic oil during the descent operation,
It is possible that the main control valve 31 does not close. FIG.
In the prior art described above, the electromagnetic pilot valve 9 does not close due to the breakage of the spring or the foreign matter in the hydraulic oil during the lowering operation.
It is possible that the main control valve 7 does not close.

In such a case, when the car 2 arrives on the floor and the electric motor 4 stops, the hydraulic oil of the hydraulic jack 1 passes through the main control valves 7 and 31 to rotate the hydraulic pump 5 in the reverse direction to the tank 6. Therefore, the car 2 temporarily stops and then descends again.

Usually, as a countermeasure, when the car 2 abnormally descends, the electric motor 4 is driven again to rotate the hydraulic pump 5 to apply braking, or the car 2 is mechanically stopped by a safety device such as a governor. However, in any of the methods, there is a time lag before the car 2 stops, and it is inevitable that the car 2 slips off the floor level.

However, if the door of the car 2 is closed, there is no significant problem as long as the car 2 can be stopped. However, in releveling or inching operation, when driving with the door of the car 2 open, it is necessary to get on and off passengers and luggage.
The occurrence of the above-described abnormalities may lead to a major accident.

[0019]

According to the present invention, apart from the main control circuit for opening and closing the main control valve to raise and lower the car 2, specific low-speed operation such as releveling and inching operation, particularly low-speed descent operation A dedicated circuit used at times is provided.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention, a dedicated circuit is provided separately from the main control valve.
This dedicated circuit is used. Also,
This dedicated circuit includes an opening / closing means that opens and closes by the pressure on the hydraulic jack side of the hydraulic pump, and an electromagnetic valve, and is configured so that the flow rate of hydraulic oil is smaller than that of the main control circuit. When the pressure on the hydraulic jack side of the hydraulic pump drops below a predetermined value, the opening / closing means is closed.

In another embodiment of the present invention, a pilot circuit of a main control valve controlled to be opened and closed by an electromagnetic pilot valve is used as a dedicated circuit. It closes and discharges the hydraulic oil of the hydraulic jack using the pilot circuit of the main control valve. Further, a means is provided for blocking the flow of hydraulic oil in the pilot circuit when the pressure on the hydraulic jack side of the hydraulic pump becomes equal to or less than a predetermined value.

[0022]

FIG. 1 shows an embodiment of the present invention. In the figure, 32 is a solenoid valve, 32a is a solenoid coil,
Reference numeral 33 denotes a pilot operation check valve, reference numeral 34 denotes a throttle, and the same reference numerals as those in FIG.

The operation of the present embodiment will be described. During a specific low-speed descent operation, the main control valve 31 is kept closed. Then, in response to a command from the control unit 30, the electric motor 4 first rotates in the upward operation direction to increase the pressure in the hydraulic jack-side pipe 5a to a predetermined pressure, and opens the pilot operation check valve 33. Then, the solenoid valve 32 is opened by exciting the solenoid coil 32a. Thereby, the hydraulic oil in the hydraulic jack 1 is pushed out by the weight of the car 2, and is discharged from the hydraulic pump 5 to the tank 6 through the pilot operation check valve 33 and the solenoid valve 32. At this time, the speed of the car 2 is controlled by controlling the rotation of the hydraulic pump 5.

When the flooring of the car 2 is completed, the solenoid coil 32a is de-energized, the solenoid valve 32 is closed, and the motor 4 is stopped. When the electric motor 4 stops and the hydraulic pump 5 stops, the pressure in the pipe 5a drops sharply, so that the pilot operation check valve 33 closes. Here, even if the solenoid valve 32 does not close for some reason, the pilot operation check valve 33 closes due to a decrease in pressure in the pipe 5a, so that the outflow of hydraulic oil from the hydraulic jack 1 is immediately stopped. Also, the aperture 34
Therefore, the outflow of hydraulic oil at this time is limited, and the car 2 hardly descends.

As described above, according to the present embodiment, the specific low-speed descent operation circuit including the solenoid valve 32, the pilot operation check valve 33, and the throttle 34 is provided separately from the main control valve 31, and the specific low-speed descent operation is performed. During operation, the main control valve 31 is not used, and a circuit dedicated to the specific low-speed descent operation with a small flow rate of the hydraulic oil is used. Abnormal descent of the car 2 can be minimized. Further, even if a power failure occurs during the specific low-speed descent operation, abnormal lowering of the car 2 can be promptly prevented without causing a free run.

Although the pilot operation check valve 33 is used in the above embodiment, the invention is not limited to this.
Any device capable of performing the same operation, such as a pressure control valve 20 as shown in FIG. Also, the throttle 34 can be omitted as long as the piping of the dedicated circuit is sufficiently thin and the flow rate of the hydraulic oil can be restricted.

Next, another embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 20 denotes a pressure control valve, 21 denotes an electromagnetic pilot valve, 21a denotes a solenoid coil, and the same reference numerals as those in FIG. The electromagnetic pilot valve 21 is controlled so as to close only during the specific low-speed descent operation, and to open during other operations.

The operation of this embodiment will be described. During ascending operation, the electromagnetic pilot valve 9 is closed and the electromagnetic pilot valve 21 is open, so that the operation is the same as that of FIG. During the descent operation, the hydraulic pump 5 is driven to control the flow rate of the hydraulic oil, so the pressure on the oil chamber 7c side is higher than the set value of the pressure control valve 20, and the pressure control valve 20 is opened. I have. When the car 2 arrives at the destination floor, the flow rate of the hydraulic oil in the main control valve 7 becomes zero, the main control valve 7 closes, the electric motor 4 stops, and the solenoid coils 8a, 9a
Are de-energized. When the electric motor stops and the hydraulic pump 5 stops, the pressure of the main control valve 7 on the oil chamber 7c side drops sharply.

Here, if the electromagnetic pilot valve 9 does not close for some reason, the hydraulic oil in the oil chamber 7d is supplied to the oil chamber via the electromagnetic pilot valve 21, the pressure control valve 20, the electromagnetic pilot valve 9, and the check valve 10. 7c, but this circuit has a resistance of the check valve 10 etc.
A response delay occurs when the main control valve 7 opens. On the other hand, oil chamber 7
Since the pressure control valve 20 closes with almost no response delay due to the pressure drop on the c side, the hydraulic oil in the oil chamber 7d does not flow out, and the main control valve 7 closes. Furthermore, even if a power failure occurs during the descent operation and the hydraulic pump 5 stops, the main control valve 7 closes quickly because the pressure control valve 20 closes.

Further, even if the electromagnetic pilot valve 9 is erroneously excited when the pressure on the oil chamber 7c side does not rise due to a failure of the electric motor 4 or the hydraulic pump 5, the pressure control valve 20 is operated in the same manner as described above. Is closed, the main control valve 7
Never open.

Next, the operation during the specific low-speed descent operation will be described. At this time, the operation is the same as the normal descent operation except that the electromagnetic pilot valve 21 is closed. Since the electromagnetic pilot valve 21 is closed, the operating oil in the oil chamber 7d does not flow out, so that the main control valve 7 does not open.

As in the case of the lowering operation described above, the hydraulic oil in the hydraulic jack 1 is pushed out by the weight of the car 2 because the solenoid coils 8a and 9a are excited and the pressure control valve 20 is open. The oil is discharged from the hydraulic pump 5 to the tank 6 through the chamber 7b, the throttle 11, the pressure control valve 20, the electromagnetic pilot valve 9, the check valve 10, and the oil chamber 7c. At this time, the rotation of the hydraulic pump 5 is controlled so that the car 2
Speed control.

When the flooring of the car 2 is completed, the solenoid coils 8a and 9a are de-energized, the electromagnetic pilot valve 9 is closed, and the motor 4 is stopped. When the electric motor 4 stops and the hydraulic pump 5 stops, the pressure in the oil chamber 7c decreases and the pressure control valve 20 closes. Therefore, even if the electromagnetic pilot valve 9 does not close for any reason, the hydraulic oil does not flow out.

As described above, according to this embodiment, the oil chamber 7
An electromagnetic pilot valve 21 that is closed only during a specific low-speed descent operation is provided on the d side, and a pressure control valve 20 that opens and closes between the electromagnetic pilot valves 8 and 9 by the pressure on the oil chamber 7c side.
Is arranged, the main control valve 7 can be prevented from opening and the car 2 can be prevented from descending even if an abnormality such as a failure of the electromagnetic pilot valve 9 occurs. Further, since the main control valve 7 is closed during the specific low speed descent operation and the pilot circuit of the main control valve 7 having a small flow rate of the hydraulic oil is used, even if an abnormality such as a power failure occurs during the specific low speed descent operation,
The lowering speed of the car 2 is not accelerated, and the lowering of the car 2 can be promptly prevented.

In the above embodiment, the pressure control valve 20 is used. However, the present invention is not limited to this, and any device capable of performing the same operation as the pilot operation check valve 33 shown in FIG. 1 may be used.

[0036]

As described above, according to the present invention,
Safety at a specific low-speed operation such as releveling or inching operation, particularly at a specific low-speed descent operation, can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of a hydraulic elevator according to one embodiment of the present invention.

FIG. 2 is a schematic diagram showing an overall configuration of a hydraulic elevator according to another embodiment of the present invention.

FIG. 3 is a schematic diagram showing the entire configuration of a conventional hydraulic elevator.

FIG. 4 is a schematic view showing the entire configuration of a conventional hydraulic elevator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic jack 2 Car 3 and 30 Control part 5 Hydraulic pump 7, 31 Main control valve 8, 9, 21 Solenoid pilot valve 20 Pressure control valve 32 Solenoid valve 33 Pilot operation check valve

Claims (4)

[Claims] A hydraulic jack for raising and lowering a car; a hydraulic pump for supplying and discharging hydraulic oil to and from the hydraulic jack; and a hydraulic pump disposed between the hydraulic jack and the hydraulic pump;
A hydraulic elevator apparatus comprising: a main control valve that allows hydraulic oil to flow in both forward and reverse directions; and a dedicated circuit used during a specific low-speed descent operation is provided separately from the main control valve. 2. A hydraulic jack for raising and lowering a car, a hydraulic pump for supplying and discharging hydraulic oil to and from the hydraulic jack, and disposed between the hydraulic jack and the hydraulic pump;
A main control valve for flowing hydraulic oil in both forward and reverse directions and a pilot circuit for opening and closing the main control valve, wherein the main control valve is closed during a specific low speed descent operation, and the pilot circuit is dedicated to a specific low speed descent operation. A hydraulic elevator apparatus configured to be used as a circuit. 3. The circuit according to claim 1, wherein the dedicated circuit includes means for preventing the flow of hydraulic oil when the pressure on the hydraulic jack side of the hydraulic pump is equal to or lower than a predetermined value. Hydraulic elevator equipment. 4. The hydraulic elevator apparatus according to claim 3, wherein the means for blocking the flow of the hydraulic oil is a pressure control valve or a pilot operation check valve.