JP3395534B2 - 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 In a conventional hydraulic elevator, when a power failure occurs during traveling of the elevator, the car may cause a free run. This phenomenon occurs when the speed of the elevator is low during descent operation, and does not occur during high speed descent operation, acceleration, and ascent operation. The cause is that the flow rate of the hydraulic oil is controlled by fully opening the main control valve and controlling the hydraulic pump during the descent operation. For this reason, when a power failure occurs during low-speed operation, the motor stops, while the main control valve is fully open, so the flow rate of hydraulic oil increases rapidly, the car enters the free-run state, and then the main control valve As the car closes, the car slows down and the car stops when the main control valve closes.

As a conventional technique for preventing this free run, 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. There are things I tried to do. This conventional technique will be described with reference to FIG. FIG. 4 is a schematic diagram showing the overall configuration of the hydraulic elevator.

In the figure, 1 is a hydraulic jack for raising and lowering a car 2, 3 is a control unit for driving a hydraulic pump 5 by controlling an electric motor 4, and 6 is a tank. Reference numeral 7 is a main control valve, and a hydraulic jack 1 is provided by a valve body 7a and hydraulic piping.
It has a jack side oil chamber 7b connected to, 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, which is a first control valve arranged between
a and 8b are solenoid coils, 9 is one check valve 1
The solenoid valve is a second control valve connected to the pump side oil chamber 7c through the other side and is connected to the back side oil chamber 7d, 9a is a solenoid coil, and 11 is a throttle arranged in parallel with the electromagnetic pilot valve 8. . In addition, each solenoid coil 8 described above
a to 9b are activated by the operation start and stop signals of the car 2 supplied from the control unit 3. 12 is a solenoid valve, 12a is a solenoid coil, 13 is a throttle valve, 14 is a relief valve,
Reference numeral 15 is a check valve.

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 working 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 descending 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.

[0013]

In the above prior art, since the main control valve 7 is directly opened by the oil discharged from the hydraulic pump 5 during the ascending operation, if an abnormality occurs during the temperature increasing operation, The car 2 may rise.
That is, during the temperature raising operation performed when the oil temperature of the hydraulic oil decreases,
The solenoid coil 12a is excited, and the oil discharged from the hydraulic pump 5 passes through the solenoid valve 12 and the throttle valve 13 to the tank 6
Reflux to. Normally, the pressure of this discharged oil is relatively low, so the main control valve 7 does not open. However, if the pressure becomes abnormally high due to a failure of the solenoid valve 12 or the like, the main control valve 7 will open and the car 2 will It may rise.

At the end of the descending operation, the electromagnetic pilot valve 9 is closed after the main control valve 7 is closed. Therefore, the electromagnetic pilot valve 9 may be damaged due to spring damage or foreign matter in the hydraulic oil. If 9 is not closed, the hydraulic oil in the rear side oil chamber 7d escapes from the hydraulic pump 5 to the tank 6, so that the closed main control valve 7 starts to open again and the car 2 descends. Furthermore, by closing the electromagnetic pilot valve 9 when a power failure occurs,
Since the main control valve 7 is closed, if the electromagnetic pilot valve 9 is not closed as in the above, the main control valve 7 cannot be closed and the car 2 descends.

If the electromagnetic pilot valve 9 is erroneously excited when the pressure on the pump-side oil chamber 7c side of the main control valve 7 is not raised due to a failure of the electric motor 4 or the hydraulic pump 5, etc. The control valve 7 opens and the car 2 descends.

[0016]

According to the present invention, the shape of the main control valve is changed to provide a front side oil chamber for opening and closing the valve body of the main control valve, and the pressure in the pump side oil chamber and the valve body It is configured so that it is independent of opening and closing.

Further, according to the present invention, means for opening and closing by the pressure on the pump side oil chamber side is provided in series with the second control valve, and the second control valve is provided.
Even if an abnormality such as a failure of the control valve occurs, the main control valve can be prevented from opening.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the embodiment of the present invention, a main control valve is provided with a jack side oil chamber, a pump side oil chamber, a back side oil chamber and a front side oil chamber around a valve body, The main control valve is prevented from opening even if the discharge oil pressure from the hydraulic pump becomes abnormally high by preventing the pressure in the pump-side oil chamber from directly affecting the opening and closing of the valve element.

Another embodiment of the present invention is to provide a valve for blocking the flow of hydraulic oil from the back side oil chamber to the pump side oil chamber when the pressure on the pump side oil chamber side is below a predetermined level. When the pressure on the pump-side oil chamber side falls below a predetermined level, this valve is closed to prevent the main control valve from opening. Furthermore, another embodiment of the present invention uses a pressure control valve or a pilot operated check valve as the valve. Furthermore, as the second control valve,
An electromagnetic pilot valve or a pressure control valve is used.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram corresponding to FIG. In the figure, 20 is a main control valve, which is arranged on the valve body 20a, the jack side oil chamber 20b connected to the hydraulic jack 1, the pump side oil chamber 20c connected to the hydraulic pump 5, and the back side of the valve body 20a. It has a rear side oil chamber 20d, a compression spring 20e, and a front side oil chamber 20f arranged on the front side of the valve body 20a. Reference numeral 21 is an electromagnetic pilot valve arranged between the front side oil chamber 20f and the check valve 10, and 21a is a solenoid coil. Moreover, the same reference numerals as those in FIG. 4 denote the same components.

The operation of this embodiment will be described. First,
Explaining the case of the ascending operation, the hydraulic pump 5 is driven and the solenoid coils 8b and 21a are excited. As a result, the pressure in the oil chamber 20f rises, and the oil chamber 2
When the valve opening force due to 0f and the pressure in the oil chamber 20b exceeds the pressure in the oil chamber 20d and the valve closing force due to the spring 20e, the valve body 20a
Starts to open and car 2 starts to rise.

As the rotation speed of the electric motor 4 increases, the flow rate of the working oil flowing through the main control valve 20 increases. As the flow rate increases, the opening degree of the main control valve 20 increases. Cage 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 starts to decrease, and the flow rate of the hydraulic oil in the main control valve 20 decreases.
The opening degree of the main control valve 20 becomes smaller. Therefore,
When the car 2 slows down and lands on the target floor, the main control valve 2
The flow rate of hydraulic oil in 0 becomes 0, the main control valve 20 is closed,
Further, the electric motor 4 stops and the solenoid coil 8
b and 21a are de-energized, and the hydraulic oil in the oil chamber 20f escapes to the tank 6.

Next, the case of the descending operation will be described. Electric motor 4
First rotates in the ascending operation direction, and the oil chamber 20c and the oil chamber 2
The pressure in the pipe connected to 0c is increased to a predetermined pressure. Then, the solenoid coils 8a, 9a, 21a are excited and the electric motor 4 is rotated in the descending operation direction. As a result, the pressure in the oil chambers 20c, 20d, 20f begins to drop, the valve body 20a begins to open due to the valve opening force of the oil chamber 20b, and the car 2 begins to descend.

When the main control valve 20 starts to open, the hydraulic oil in the hydraulic jack 1 passes through the main control valve 20 and the hydraulic pump 5
Is discharged to the tank 6. Further, the opening degree of the main control valve 20 increases as the flow rate of the hydraulic oil in the main control valve 20 increases. At this time, the electric motor 4 drives the hydraulic pump 5 by a signal from the control unit 3 to control the flow rate of the hydraulic oil,
Accelerate the lowering 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 20 decreases,
The opening of will become smaller. Therefore, when the car 2 decelerates and lands on the target floor, the flow rate of hydraulic oil in the main control valve 20 becomes 0, the main control valve 20 closes, and the electric motor 4
Is stopped and the solenoid coils 8a, 9a, 2
1a is de-excited, and the hydraulic oil in the oil chamber 20f escapes to the tank 6.

As described above, in this embodiment, as in the case of the prior art, the opening of the main control valve 7 increases or decreases according to the flow rate of the hydraulic oil, so that the car 2 causes a free run. There is no. Further, in this embodiment, except during the ascending and descending operation,
The electromagnetic pilot valve 21 is closed. That is, since the hydraulic oil in the oil chamber 20f is discharged to the tank 6, the valve body 20a moves even if the pressure of the oil discharged from the hydraulic pump 5 becomes abnormally high due to the occurrence of an abnormality during the temperature increasing operation. Not,
The car 2 never rises.

According to the present embodiment, when the hydraulic pump 5 is stopped after the end of the descending operation, even if the electromagnetic pilot valve 21 cannot be closed due to spring damage or foreign matter in the hydraulic oil, the electromagnetic pilot valve 21 will not be closed. If the valve 9 closes normally, the car 2 will not descend. That is, the hydraulic oil in the oil chamber 20f is the electromagnetic pilot valve 21, the oil chamber 20c, and the hydraulic pump 5.
From the tank to the tank 6 and lowering, while the oil chamber 20d
Since the hydraulic oil is stopped by the electromagnetic pilot valve 9 and becomes high, the valve body 20a does not open, and thus the car 2 does not descend.

As described above, according to this embodiment, as in the case of the prior art, it has the effect of preventing free run when a power failure occurs, and the effect of preventing an abnormal rise of the car 2 during temperature rising operation and the electromagnetic effect. It has an effect of preventing the abnormal lowering of the car 2 due to the pilot valve 21.

Next, another embodiment of the present invention will be described with reference to FIG. This embodiment corresponds to the occurrence of an abnormality in the electromagnetic pilot valve 9, that is, the second control valve. Compared to the embodiment of FIG. 1, the pressure control valve 30 is arranged between the electromagnetic pilot valves 8 and 9, and The pilot circuit 31 is added.

The operation of this embodiment will be described. Since the electromagnetic pilot valve 9 is not operated during the ascending operation, the pressure control valve 30 is irrelevant and the operation is the same as that of the embodiment of FIG. During the lowering operation of the car 2, the hydraulic pump 5 is driven to control the flow rate of the hydraulic oil, so the pressure of the pilot circuit 31 is higher than the set value of the pressure control valve 30, and the pressure control valve 30 Is open. When the car 2 is landed on the target floor, the flow rate of hydraulic oil in the main control valve 20 becomes 0, the main control valve 20 is closed, the electric motor 4 is stopped, and the solenoid coils 8a, 9a, 21a are It is de-excited and the oil in the oil chamber 20f escapes to the tank 6. Further, when the electric motor 4 stops and the hydraulic pump 5 stops, the pressure in the pump-side oil chamber 20c sharply drops.

If the electromagnetic pilot valve 9 does not close for some reason, the hydraulic oil in the rear side oil chamber 20d tries to flow to the pump side oil chamber 20c via the pressure control valve 30 and the electromagnetic pilot valve 9. However, since there is resistance of the check valve 10 and the like in this circuit, a response delay occurs when the valve body 20a moves in the opening direction. On the other hand, the pump side oil chamber 20c
Since the pressure control valve 30 closes with almost no response delay due to the pressure drop on the side, the hydraulic oil in the rear side oil chamber 20d does not flow out, and the main control valve 20 closes.

Further, even if the electromagnetic pilot valve 9 is erroneously excited when the pressure on the pump side oil chamber 20c side is not rising due to a failure of the electric motor 4 or the hydraulic pump 5, or the like,
Since the pressure control valve 30 is closed as described above, the main control valve 20 does not open.

As described above, according to this embodiment, since the pressure control valve 30 which opens and closes by the pressure on the pump side oil chamber 20c side is arranged between the electromagnetic pilot valves 8 and 9, the electromagnetic pilot valve 9 fails. Even if an abnormality such as the above occurs, it is possible to prevent the main control valve 20 from opening and prevent the car 2 from descending.

Although the pressure control valve 30 is used in the above embodiment, the present invention is not limited to this, and any pilot operation check valve or the like that can perform the same operation may be used.

Next, still another embodiment of the present invention will be described with reference to FIG. In this embodiment, as the second control valve, a pressure control valve 40 is arranged instead of the electromagnetic pilot valve 9, and a pilot circuit 41 and a throttle 42 are added.

The operation of this embodiment will be described. During the ascending operation, the hydraulic pump 5 is driven and the solenoid coils 8b and 21a are excited to drive the valve body 2 as in the case of FIG.
0a starts to open, and the car 2 starts to rise. At this time, the pressure control valve 40 opens as the pressure on the pump-side oil chamber 20c side increases, but since there is the check valve 10, the hydraulic oil does not flow. Then, when the car 2 is landed on the target floor, the flow rate of the hydraulic oil in the main control valve 20 becomes 0, the main control valve 20 is closed, and further the electric motor 4 is stopped,
The solenoid coils 8b and 21a are de-energized, and the oil chamber 2
Oil of 0f escapes to the tank 6. Also, the pump side oil chamber 20
The pressure control valve 40 closes as the pressure on the c side decreases.

Next, the case of the descending operation will be described. Electric motor 4
First rotates in the ascending operation direction to increase the pressure on the pump side oil chamber 20c side to a predetermined pressure. As a result, the pressure control valve 4
0 opens. Then, while exciting the solenoid coils 8a and 21a, the electric motor 4 is rotated in the descending operation direction,
The descending operation of the car 2 is the same as in the case of FIG.

When the car 2 is landed on the target floor, the flow rate of the hydraulic oil in the main control valve 20 becomes 0, the main control valve 20 is closed, the electric motor 4 is stopped, and the solenoid coils 8a and 21a are connected. Is de-excited and the oil in the oil chamber 20f escapes to the tank 6.

At this time, as the pressure on the pump side oil chamber 20c side drops, the working oil in the back side oil chamber 20d becomes the pump side oil chamber 2
Although it tries to flow to the 0c side, there is a time delay due to the resistance of the pressure control valve 40, the check valve 10, the throttle 41 and the like. On the other hand, since the pressure control valve 40 closes with almost no time delay due to the pressure drop on the pump side oil chamber 20c side,
The hydraulic oil in the rear side oil chamber 20d does not flow out, and the main control valve 20 is closed.

As described above, this embodiment also has the same structure and function as the embodiment of FIG. 1, and has the effect of preventing free run when an abnormality occurs and preventing the abnormal rise of the car 2 during temperature rising operation. Have an effect. Although the pilot circuit 41 of the pressure control valve 40 is connected to the pump-side oil chamber 20c side in FIG. 3, it may be connected to the front-side oil chamber 20f. In addition, the pressure control valve 40 includes a solenoid pilot valve 9 shown in FIG.
Can be additionally connected in series. Furthermore, as shown in FIG. 2, a pressure control valve 30, a check valve, etc. can be added.

[0041]

As described above, according to the present invention,
Even if an abnormality occurs during the temperature rising operation, there is no fear that the car will rise, and even if a failure of the second control valve, mis-excitation or the like occurs, a simple device is simply added. The safety of the hydraulic elevator can be improved by preventing the car from descending due to a failure of the control valve of.

[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 an overall configuration of a hydraulic elevator according to another embodiment of the present invention.

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

[Explanation of symbols]

1 hydraulic jack Two baskets 3 control unit 7,20 Main control valve 7a, 20a valve body 7b, 20b Jack side oil chamber 7c, 20c Pump side oil chamber 7d, 20d Rear side oil chamber 7e, 20e spring 8 First control valve 9 Second control valve 20f Front oil chamber 21 Solenoid pilot valve 30,40 Pressure control valve

Claims (6)

(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 one provided with a main control valve for circulating hydraulic oil in both forward and reverse directions, the main control valve comprises a valve body for opening and closing a passage for hydraulic oil, a jack side oil chamber connected to a hydraulic jack side, and a hydraulic pressure. A pump-side oil chamber connected to the pump side, a back-side oil chamber that biases the valve element in the closing direction at high pressure, a front-side oil chamber that biases the valve element in the opening direction at high pressure, and And a means for urging the valve body in the closing direction, wherein the front side oil chamber is configured to maintain a low pressure state when the car is stopped.
Cage, multiply the pump-side from the rear side oil chamber during lowering operation of the car
Means for allowing hydraulic oil to flow to the oil chamber, and the pump
When the pressure in the side oil chamber is below a certain level,
Equipped with means for blocking the flow of hydraulic oil to the pump-side oil chamber
The hydraulic elevator system is characterized by 2. A hydraulic jack for raising and lowering a car, and a front
Hydraulic pump that supplies and discharges hydraulic oil to the hydraulic jack
And disposed between the hydraulic jack and the hydraulic pump,
It also has a main control valve that allows hydraulic oil to flow in both the forward and reverse directions.
In the above, the main control valve includes a valve body that opens and closes a passage for hydraulic oil, and a hydraulic pressure.
Jack side oil chamber connected to jack side and hydraulic pump
And the pump-side oil chamber connected to the
Back side oil chamber that urges in the direction and open the valve body at high pressure
Front side oil chamber that urges in the direction
A first means for enabling the flow of hydraulic oil between the jack side oil chamber and the back side oil chamber during the ascending operation of the car.
Second means for limiting the flow rate of hydraulic oil from the jack side oil chamber to the back side oil chamber during the descent operation of the car; and the pump side oil from the back side oil chamber during the descent operation of the car. third means and, passenger cage of hydraulic elevator during stop you characterized by comprising a fourth means for the front side oil chamber to the low pressure state to allow the flow of hydraulic fluid to the chamber apparatus. 3. A means for blocking the flow of hydraulic oil from the back side oil chamber to the pump side oil chamber when the pressure on the side of the pump side oil chamber is below a predetermined level. 2. The hydraulic elevator device according to item 2 . 4. A means for preventing the flow of the hydraulic oil, hydraulic elevator system of claim 1 or 3, characterized in that a pressure control valve or pilot operated check valve. 5. The oil on the back side during the descending operation of the car
A solenoid pilot valve is provided as means for enabling the flow of hydraulic oil from a chamber to the pump-side oil chamber.
5. The hydraulic elevator device according to any one of 1 to 4. 6. The oil on the back side during the descending operation of the car
The means for allowing the working oil to flow from the chamber to the pump-side oil chamber is a means for opening when the pressure in the pump-side oil chamber or the front-side oil chamber is equal to or higher than a predetermined value. The hydraulic elevator apparatus according to any one of claims 1 to 4.