JP3399251B2 - Hydraulic elevator equipment - Google Patents

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 that controls an electric motor by inverter control or the like to control the discharge oil amount of a hydraulic pump driven by the electric 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 hydraulic pump 5 is rotationally controlled and hydraulic oil is supplied to the hydraulic jack 1 via the main control valve 31 to raise the car 2. Further, when the car 2 descends, the solenoid coil 31a is excited to fully open the main control valve 31, the hydraulic pump 5 is rotationally controlled, and hydraulic oil is discharged from the hydraulic jack 1 via the main control valve 31. Lower the car 2.

By the way, in the hydraulic elevator shown in FIG. 3, if a power failure occurs while the car 2 is descending 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 descending operation. For this reason, when a power failure occurs during low-speed descent operation, the electric motor 4 stops, while the main control valve 31 is fully open, so the flow rate of hydraulic oil rapidly increases, and the car 2 enters the free-run state, and then the The car 2 is decelerated as the main control valve 31 is closed, and the car 2 is stopped when the main control valve 31 is completely closed.

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

In the figure, 7 is a main control valve, and a valve body 7
a, a jack side oil chamber 7b connected to the hydraulic jack 1 by hydraulic piping, 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 arranged between them, 8a and 8b are solenoid coils, 9 is an electromagnetic pilot valve connected to the pump side oil chamber 7c via the check valve 10 and the other 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 the solenoid coils 8a to 9a.

Next, the operation of this prior art will be described. First, the case of the 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 to equalize the pressures in the oil chambers 7b and 7d. Therefore, when the valve opening force due to the pressure in the oil chamber 7c and the oil chamber 7b exceeds the pressure in the oil chamber 7d and the valve closing force due to the spring 7e, the valve body 7a starts to open and the car 2 starts to rise.

Then, the flow rate of the hydraulic oil flowing through the main control valve 7 increases as the rotation speed of the electric motor 4 increases, and the opening degree of the main control valve 7 (of the valve body 7a increases as the flow rate increases). The moving amount) becomes large, and the car 2 accelerates. When the car 2 travels at the rated speed and reaches the deceleration start point of the target floor, the rotation speed of the electric motor 4 begins to decrease, the flow rate of hydraulic oil in the main control valve 7 decreases, and the main control valve 7 The opening becomes smaller. Therefore, when the car 2 starts decelerating and lands on the target floor, the flow rate of hydraulic oil in the main control valve 7 becomes 0, the main control valve 7 is closed, and the electric motor 4 is stopped. Further, the electromagnetic pilot valve 8 holds the same position until the solenoid coil 8a is excited.

As described above, during the ascending operation, the main control valve 7
Since the opening degree of the main control valve 7 increases and decreases according to the flow rate of the hydraulic oil, the opening degree of the main control valve 7 is the minimum necessary. Therefore, even if a power failure occurs during the ascending operation, the main control valve 7 closes quickly as the flow rate of the working oil in the main control valve 7 becomes 0, so that the working oil flows backward and the car 2 Does not cause a free run.

Next, the case of the descending operation will be described. Control unit 3
In response to a command from the electric motor 4, the electric motor 4 first rotates in the ascending operation direction to prevent the starting shock of the car 2 and the oil chamber 7c
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, 7d begins to drop, and the oil chambers 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 body 7a starts to open,
The 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 as the flow rate of the hydraulic oil in the main control valve 7 increases. 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 descent of the car 2.

When the car 2 travels at the rated speed and reaches the deceleration start point of the target floor, the rotation speed of the electric motor 4 begins to decrease,
The flow rate of hydraulic 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 decelerating and lands on the target floor, the flow rate of the hydraulic oil in the main control valve 7 becomes 0, 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 descent operation, the opening degree of the main control valve 7 is increased / decreased according to the flow rate of the hydraulic oil, and is the minimum required opening degree.

When a power failure occurs during the descent operation, the solenoid coil 9a is de-energized, the electromagnetic pilot valve 9 is closed, and the hydraulic oil in the oil chamber 7b is supplied to the oil chamber 7d through the throttle 11. Therefore, the valve body 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 is slowly closed. Therefore, the car 2 will not be greatly shocked. Thus, the car 2 does not cause a free run even during the descent operation.

[0015]

In the prior art shown in FIG. 3, even if the solenoid coil 31a is de-excited due to damage to the spring during descent operation or foreign matter in the hydraulic oil,
It is possible that the main control valve 31 does not close. Also, FIG.
In the prior art, the electromagnetic pilot valve 9 does not close due to damage to the spring during descent operation or foreign matter in the hydraulic oil.
The main control valve 7 may not close.

In such a case, when the car 2 is landed on the floor and the electric motor 4 is stopped, the hydraulic oil of the hydraulic jack 1 passes through the main control valves 7 and 31 while the hydraulic pump 5 is reversed and the tank 6 is rotated. Therefore, the car 2 stops once and then descends again.

As a countermeasure against this, normally, when the car 2 is abnormally lowered, the electric motor 4 is driven again to brake by rotating the hydraulic pump 5, or the car 2 is mechanically stopped by a safety device such as a governor. Although there is a method of making the car 2 or the like, there is a time lag before the car 2 stops in any of the methods, and therefore the car 2 cannot avoid slipping from the floor level.

However, in the case where the door of the car 2 is closed, as long as the car 2 can be stopped, no serious problem occurs. However, in releveling or inching operation, when driving with the door of the car 2 open, passengers, luggage, etc. get on and off,
If the above-mentioned abnormality occurs, it may lead to a serious accident.

[0019]

According to the present invention, apart from the main control circuit for opening and closing the car 2 by opening and closing the main control valve, a specific low speed operation such as releveling or inching operation, particularly low speed descending operation is performed. A special circuit used at times is provided.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In the embodiment of the present invention, a dedicated circuit is provided in addition to the main control valve, and during a specific low speed descent operation,
This dedicated circuit is used. Also,
This dedicated circuit is provided with 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 in the main control circuit. The opening / closing means is closed when the pressure on the hydraulic jack side of the hydraulic pump falls below a predetermined level.

In another embodiment of the present invention, the pilot circuit of the main control valve which is controlled to open and close by the electromagnetic pilot valve is used as a dedicated circuit, and the main control valve is operated during a specific low speed descent operation. The hydraulic oil of the hydraulic jack is discharged by closing the pilot circuit of the main control valve. Further, there is provided means for blocking the flow of the hydraulic oil in the pilot circuit when the pressure on the hydraulic jack side of the hydraulic pump falls below a predetermined level.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In the figure, 32 is a solenoid valve, 32a is a solenoid coil,
Reference numeral 33 is a pilot operation check valve, 34 is a throttle, and the same reference numerals as in FIG.

The operation of this embodiment will be described. The main control valve 31 is kept closed during the specific low speed descent operation. Then, in response to a command from the control unit 30, the electric motor 4 first rotates in the ascending 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 coil 32a is excited to open the solenoid valve 32. As a result, the hydraulic oil in the hydraulic jack 1 is pushed out by the weight of the car 2, passes through the pilot operation check valve 33 and the electromagnetic valve 32, and is discharged from the hydraulic pump 5 to the tank 6. At this time, the hydraulic pump 5 is rotationally controlled to control the speed of the car 2.

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

As described above, according to this embodiment, the specific low speed descent operation dedicated 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. Since the main control valve 31 is not used during operation and the circuit for specific low speed descent operation with a small flow rate of hydraulic oil is used, even if an abnormality occurs in the solenoid valve 32 during the specific low speed descent operation, The abnormal drop of the car 2 can be minimized. Further, even if a power failure occurs during the specific low speed descent operation, it is possible to quickly prevent an abnormal descent of the car 2 without causing a free run.

Although the pilot operated check valve 33 is used in the above embodiment, the invention is not limited to this.
A pressure control valve 20 as shown in FIG. 2 to be described later may be used as long as it can perform the same operation. The throttle 34 may be omitted if the piping of the dedicated circuit is sufficiently thin and the flow rate of the hydraulic oil can be limited.

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

The operation of this embodiment will be described. During the ascending operation, the electromagnetic pilot valve 9 is closed and the electromagnetic pilot valve 21 is open, so the operation is the same as that shown in FIG. During the lowering operation, since the hydraulic pump 5 is driven to control the flow rate of the hydraulic oil, 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 remains open. There is. When the car 2 is landed on the target floor, the flow rate of hydraulic oil in the main control valve 7 becomes 0, the main control valve 7 is closed, the electric motor 4 is stopped, and the solenoid coils 8a, 9a
Is de-energized. When the electric motor stops and the hydraulic pump 5 stops, the pressure on the oil chamber 7c side of the main control valve 7 drops sharply.

Here, if the electromagnetic pilot valve 9 does not close due to some reason, the hydraulic oil in the oil chamber 7d passes through the electromagnetic pilot valve 21, the pressure control valve 20, the electromagnetic pilot valve 9, and the check valve 10 to the oil chamber. It tries to flow to 7c, but because there is resistance such as check valve 10 in this circuit,
There is a response delay in opening the main control valve 7. On the other hand, oil chamber 7
Since the pressure control valve 20 is closed with almost no response delay due to the pressure decrease on the c side, the hydraulic oil in the oil chamber 7d does not flow out, and the main control valve 7 is closed. Further, even when a power failure occurs during the lowering operation and the hydraulic pump 5 stops, the pressure control valve 20 closes, so the main control valve 7 closes quickly.

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

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

Similar to the descent operation described above, since the solenoid coils 8a and 9a are excited and the pressure control valve 20 is opened, the hydraulic oil in the hydraulic jack 1 is pushed out by the weight of the car 2 and the oil is discharged. 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 floor alignment of the car 2 is completed, the solenoid coils 8a and 9a are de-energized, the electromagnetic pilot valve 9 is closed, and the electric motor 4 is stopped. When the electric motor 4 stops and the hydraulic pump 5 stops, the pressure in the oil chamber 7c drops and the pressure control valve 20 closes. Therefore, even if the electromagnetic pilot valve 9 does not close for some reason, the hydraulic oil does not flow out.

As described above, according to this embodiment, the oil chamber 7
An electromagnetic pilot valve 21 is provided on the d side that is closed only during a specific low speed descent operation, 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
Since the structure is provided, even if an abnormality such as a failure of the electromagnetic pilot valve 9 occurs, the opening of the main control valve 7 can be prevented and the lowering of the car 2 can be prevented. 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 with a small flow rate of hydraulic oil is used, even when an abnormality such as a power failure occurs during the specific low speed descent operation,
The descent speed of the car 2 is not accelerated, and the descent of the car 2 can be promptly prevented.

Although the pressure control valve 20 is used in the above embodiment, the present invention is not limited to this, and any pilot operation check valve 33 shown in FIG.

[0036]

As described above, according to the present invention,
It is possible to improve safety in a specific low speed operation such as releveling or inching operation, particularly in a specific low speed descent operation.

[Brief description of drawings]

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

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

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

FIG. 4 is a schematic diagram showing the overall configuration of a conventional hydraulic elevator.

[Explanation of symbols]

1 hydraulic jack Two baskets 3,30 Control unit 5 hydraulic pump 7,31 Main control valve 8, 9, 21 Solenoid pilot valve 20 Pressure control valve 32 Solenoid valve 33 Pilot operated check valve

Claims (3)

(57) [Claims] 1. 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 arranged between the hydraulic jack and the hydraulic pump.
In the one provided with a main control valve for circulating hydraulic oil in both forward and reverse directions, a dedicated circuit used during a specific low speed descent operation is provided separately from the main control valve, and this dedicated circuit is provided with a dedicated circuit for the hydraulic pump.
When the pressure on the hydraulic jack side is below a certain level, the hydraulic oil
A hydraulic elevator apparatus comprising means for blocking distribution . 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 a hydraulic pump arranged between the hydraulic jack and the hydraulic pump.
A main control valve that allows hydraulic oil to flow in both the forward and reverse directions and a pilot circuit that opens and closes this main control valve.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. It is configured to be used as a circuit and the hydraulic jack of the hydraulic pump is
When the pressure on the key side is below a certain level, the flow of hydraulic oil is blocked.
A hydraulic elevator apparatus comprising: 3. The means for preventing the flow of hydraulic fluid is a pressure
It is a force control valve or a pilot operated check valve.
The hydraulic elevator apparatus according to claim 1, wherein the hydraulic elevator apparatus is a characteristic.