JPH0873142A - Hydraulic elevator device - Google Patents

Abstract

PURPOSE: To quicken the responsiveness of restart of a hydraulic elevator device after it has stopped. CONSTITUTION: This hydraulic elevator device controls pressure between a hydraulic cylinder 2 and a first check valve 12 and pressure between a flow control valve 7 and a second check valve 14 so that they may be become uniform by adjusting the operation timing of the first check vavle 12 and the second check valve 14 by a controller 11 while a riding box 1 is stopped. It also controls a pump electric motor 9 by the controller 11 so that pressure between the hydraulic cylinder 2 and the first check valve 12 and pressure between the flow control valve 7 and the second check valve 14 may become uniform while the box 1 is stopped. Thus stopping shook is restrained and responsiveness is improved by reducing the time lag from the time when the starting command is issued to the time when the box actually starts to move.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic elevator system.

[0002]

2. Description of the Related Art Generally, a hydraulic elevator system adopts a flow rate control system for controlling the oil flow rate for controlling the speed of a car, and a revolution speed control system for controlling the rotational speed of a hydraulic pump. And are mainly known.

In a hydraulic elevator system adopting a flow rate control system, when a car is raised, an electric motor for driving a hydraulic pump is rotated at a constant speed, and a constant discharge amount of oil supplied from the hydraulic pump to a hydraulic cylinder is supplied. Is fully returned to the oil tank, and when a command to start the elevator is issued, the flow rate of the oil that flows back from the hydraulic cylinder to the oil tank is adjusted by the flow control valve, which causes the plunger to project from the hydraulic cylinder and raise the car. And control the speed of the car. When the car is descending, the speed of the car is controlled by adjusting the flow rate of the oil in the hydraulic cylinder that flows back to the oil tank due to the weight of the car by the flow control valve. When executing these speed controls, the flow rate control valve controls the current value given to the flow rate control valve from the control device, thereby controlling the passage of the oil of the flow rate corresponding to the current value.

On the other hand, in a hydraulic elevator system which employs a rotational speed control system of a hydraulic pump, the electric motor of the hydraulic pump is operated at a variable speed by using inverter control, and thereby the rotational speed of the hydraulic pump is controlled to control the oil flow rate. To control the speed of the car.

[0005]

However, such a conventional hydraulic elevator apparatus has the following problems. That is, in any type of hydraulic elevator apparatus, the check valve installed between the hydraulic cylinder and the hydraulic pump is closed when the car is stopped. The pressure on the hydraulic cylinder side is determined by the car weight and the load. Further, the pressure on the hydraulic pump side becomes equal to the atmospheric pressure because the oil tank side is open. Therefore, there is a large gap between the pressure on the hydraulic cylinder side and the pressure on the hydraulic pump side, and when restarting from this state, a large vibration occurs at the time of startup.

Therefore, in order to eliminate this vibration, a first pressure sensor is conventionally installed between the hydraulic cylinder and the check valve in Japanese Patent Laid-Open No. 3-106785 to check the check valve and the hydraulic pump. Install a second pressure sensor between
A method has been proposed in which the deviation of the pressure detected by these pressure sensors is controlled to be a predetermined value or less.

However, in this proposed method,
Particularly in the case of the rotational speed control system, it is necessary to control the pressure between the hydraulic pump and the check valve after compensating the leak flow rate of the hydraulic pump with the temperature and pressure of the oil. Therefore, since it becomes necessary to efficiently perform the machine difference adjustment by the hydraulic pump for each temperature and pressure, the adjustment takes time. In particular, during down operation, there is a problem that there is a time delay between the start of the command to output the pressure after the hydraulic pump is reversely rotated to increase the pressure and the speed control is performed until the car actually starts moving. It was

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to obtain a traveling characteristic having a good responsiveness with a simple structure, without being influenced by variations in performance and characteristics of hydraulic equipment. An object of the present invention is to provide a hydraulic elevator device that can be used.

[0009]

According to a first aspect of the present invention, there is provided a hydraulic cylinder for raising and lowering a car, a hydraulic pump for allowing pressurized oil to pass through the hydraulic cylinder, and an oil tank for retaining the oil. The flow rate of oil that is sucked up from the oil tank by the hydraulic pump and is supplied to the hydraulic cylinder during the ascending operation of the car, and the flow rate of oil that is recirculated from the hydraulic cylinder to the oil tank during the descending operation of the car are described. In a hydraulic elevator device of a flow control system, which comprises a flow control valve for controlling and a pump electric motor for driving the hydraulic pump, a first check valve installed on the way of piping between the hydraulic cylinder and the hydraulic pump. A valve, a second check valve installed on the way between the oil tank and the hydraulic pump, and a pressure between the hydraulic cylinder and the first check valve when stopped. A valve control device for controlling the operation timing of the first and second check valves so that the pressure between the first check valve and the second check valve becomes equal. It is a thing.

According to a second aspect of the present invention, in the hydraulic elevator system according to the first aspect, the pressure between the hydraulic cylinder and the first check valve during stoppage, the first check valve and the second check valve are further increased.
A pressure control device for controlling the pump motor so that the pressure between the check valve and the check valve becomes equal.

According to a third aspect of the present invention, in the hydraulic elevator system according to the second aspect, further, there is provided a first pressure sensor for detecting a pressure between the hydraulic cylinder and the first check valve, and the first pressure sensor. A second pressure sensor for detecting the pressure between the check valve and the second check valve, wherein the pressure control device controls the equal pressure based on the pressure detection values of the first and second pressure sensors. It is something that is done.

According to a fourth aspect of the present invention, a hydraulic cylinder for raising and lowering a car, a hydraulic pump for passing pressure oil to the hydraulic cylinder, an oil tank for retaining the oil, and the hydraulic pump are driven. In a hydraulic elevator device of a rotation speed control system comprising a pump motor and an inverter device for performing variable speed control of the pump motor,
A first check valve installed along the pipe between the hydraulic cylinder and the hydraulic pump; a second check valve installed along the pipe between the oil tank and the hydraulic pump; The pressure between the hydraulic cylinder and the first check valve and the first check valve
And a valve control device for controlling the operation timing of the first and second check valves so that the pressure between the check valve and the second check valve becomes equal. .

According to a fifth aspect of the present invention, in the hydraulic elevator system according to the fourth aspect, the pressure between the hydraulic cylinder and the first check valve, the first check valve, and the second check valve during stop are further provided.
A pressure control device for controlling the pump motor so that the pressure between the check valve and the check valve becomes equal.

According to a sixth aspect of the present invention, in the hydraulic elevator system according to the fifth aspect, a first pressure sensor for detecting the pressure between the hydraulic cylinder and the first check valve is further provided, and the first pressure sensor is provided. A second pressure sensor for detecting the pressure between the check valve and the second check valve, wherein the pressure control device controls the equal pressure based on the pressure detection values of the first and second pressure sensors. It is something that is done.

[0015]

In the hydraulic elevator system according to the present invention, when the car is stopped, the operation timing of the first check valve and the second check valve is adjusted by the valve control device so that the hydraulic cylinder and the first check valve are adjusted. And the pressure between the flow control valve and the second check valve are controlled to be equal pressure.

With this, it is not necessary to control the shock at the time of stop and to make the pressures on the hydraulic cylinder side and the hydraulic pump side equal when restarting from the stopped state. It is possible to reduce the time delay from the occurrence of the car until the car actually starts moving, and improve the responsiveness.

According to a second aspect of the present invention, in the hydraulic elevator system according to the first aspect, the pressure between the hydraulic cylinder and the first check valve, the flow control valve, and the second check valve are further activated during stoppage. The pump motor is controlled by the pressure control device so that the pressure between them becomes equal.

With this, the pressure on the hydraulic pump side can be maintained at a predetermined pressure even when a leak occurs in the second check valve, and when restarting from the stopped state. It is not necessary to control the pressures on the hydraulic cylinder side and hydraulic pump side to be equal, and the time delay from the generation of the start command to the actual movement of the car can be further reduced, and the responsiveness can be improved. Can be further improved.

According to another aspect of the hydraulic elevator apparatus of the present invention, the first pressure sensor for detecting the pressure between the hydraulic cylinder and the first check valve, the first check valve and the second check valve are provided. A second pressure sensor that detects the pressure between the valve and the valve, and the pressure control device performs equal pressure control based on the pressure detection values of the first and second pressure sensors. Can be controlled to be exactly equal.

In the hydraulic elevator system according to the fourth aspect of the present invention, when the car is stopped, the operation timings of the first check valve and the second check valve are adjusted by the valve control device so that the hydraulic cylinder and the first check valve are adjusted. And the pressure between the first check valve and the second check valve are controlled to be equal pressure.

As a result, the shock at the time of stop is suppressed, and when restarting from the stopped state, it is not necessary to control so that the pressures on the hydraulic cylinder side and the hydraulic pump side become equal, and the start command is issued. It is possible to reduce the time delay from the occurrence of the car until the car actually starts moving, and improve the responsiveness.

According to a fifth aspect of the present invention, in the hydraulic elevator system according to the fourth aspect, the pressure between the hydraulic cylinder and the first check valve, the first check valve and the second check valve are further increased during stoppage. The pressure control device controls the pump motor so that the pressure between the stop valve and the valve is equal.

With this arrangement, the pressure on the hydraulic pump side can be maintained at a predetermined pressure even when a leak occurs in the second check valve, and when restarting from the stopped state. It is not necessary to control the pressures on the hydraulic cylinder side and hydraulic pump side to be equal, and the time delay from the generation of the start command to the actual movement of the car can be further reduced, and the responsiveness can be improved. Can be further improved.

According to another aspect of the hydraulic elevator apparatus of the present invention, the first pressure sensor for detecting the pressure between the hydraulic cylinder and the first check valve, the first check valve and the second check valve are provided. A second pressure sensor that detects the pressure between the valve and the valve, and the pressure control device performs equal pressure control based on the pressure detection values of the first and second pressure sensors. Can be controlled to be exactly equal.

[0025]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a common embodiment of the inventions of claims 1 to 3. The hydraulic elevator system of this embodiment is
It adopts a flow rate control method, and includes a car 1, a hydraulic cylinder 2, a plunger 3 driven by the hydraulic cylinder 2, a pulley 4 driven up and down by the plunger 3, and a rope 5 wound around the pulley 4. And the car 1 is connected to one end of this rope 5,
As the plunger 3 and pulley 4 move up and down, the rope 5
It is designed to be driven up and down by.

The hydraulic elevator system also includes a flow control valve 7 for controlling the flow rate of the pressure oil to be passed through the hydraulic cylinder 2 through the pipe 6, a hydraulic pump 8 for supplying oil, an electric motor 9 for driving the hydraulic pump 8, and oil. A storage oil tank 10 and a control device 11 for controlling the operation of the flow control valve 7 and the electric motor 9 are provided.

The hydraulic elevator system of this embodiment is further characterized in that a first check valve 12 and a first pressure sensor 13 are provided in the middle of the pipe 6 between the hydraulic cylinder 2 and the flow control valve 7. A second check valve 14 is provided in the middle of the pipe between the hydraulic pump 8 and the oil tank 10, and a second pressure sensor 15 is provided between the flow control valve 7 and the hydraulic pump 8.

In addition, in the hydraulic elevator system of this embodiment, the car 1 is provided with the speed sensor 16, and when the car 1 moves up and down along the guide rail 17, the car 1 rotates while contacting the guide rail 17. It is designed to detect speed.

The above-mentioned control device 11 uses this speed sensor 16
From the first and second pressure sensors 13 and 15 to control the valve opening of the flow control valve 7 for speed control of the car 1 and the pump motor. 9 and also controls the first and second check valves 12, 1
4, which is configured by a microcomputer.

Next, the operation of the hydraulic elevator system constructed as above will be described with reference to FIGS.

<< Descent Operation >> When the descending operation is performed from the stopped state of the car 1, operation control is performed according to the timing chart of FIG. 2 and the sequence of FIG.

First, when the car 1 is stopped, both the first check valve 12 and the second check valve 14 are closed.
When the descending operation start command DC is issued, the second check valve 1
The open signal Vpt for 4 is turned on after a time delay of τds1 to open the second check valve 14, and the oil between the first check valve 12 and the second check valve 14 becomes an oil tank. It begins to flow to 10. After a time delay of τds2, the first check valve 1
The release signal Vpc for 2 is turned on, and the oil on the hydraulic cylinder 1 side flows out to the oil tank 10 via the first check valve 12. Therefore, after a time delay τds3, the down valve opening signal PENA is output to the flow control valve 7, and by controlling the down valve of this flow control valve 7, the flow rate of the oil flowing back from the hydraulic cylinder 1 to the oil tank 10 is controlled. , Controls the descent speed of the plunger 2 and the car 1.

When the car 1 arrives at the destination floor and stops, the descending control command DC turns off, and in synchronization with this, the descending valve open signal PENA turns off. After that, in order to reduce the stop shock and equalize the pressures of the hydraulic pump 8 and the hydraulic cylinder 2, the open signal V of the first check valve 12 is passed after a time delay τde1.
Turn off pc, and after a further time delay τde2, the second check valve 1
The open signal Vpt of 4 is turned off.

<< Climbing Operation >> When the climbing operation is performed from the stopped state of the car 1, the operation control is performed according to the timing chart of FIG. 4 and the sequence of FIG.

First, when the car 1 is stopped, both the first check valve 12 and the second check valve 14 are closed.
Then, when the ascending operation start command UC is issued, the first check valve 1
The open signal Vpc for 2 is turned on after the time delay of τus1 to open the first check valve 12, and after the time delay of τus2, the open signal Vpt for the second check valve 14 is turned on and the first check valve 12 is turned on. The check valve 14 of No. 2 is opened. Further, after a time delay of τus3, the operation signal PENA of the hydraulic pump 8 is turned on. This time delay τus3 needs to be made as short as possible in order to prevent the reverse flow of oil from the hydraulic cylinder 2 to the oil tank 10. As a result, the rising valve closing signal PENA is output to the flow rate control valve 7 when the hydraulic pump 8 is started, and by closing the rising valve of the flow rate control valve 7, the flow rate of the oil flowing back to the oil tank 10 is gradually reduced. Then, on the contrary, the oil flows into the hydraulic cylinder 2. Therefore, based on the speed pattern generated by the control device 11, the lift valve opening degree of the flow control valve 7 is adjusted to control the oil discharge amount from the hydraulic pump 8 and the oil of this controlled flow rate is supplied to the hydraulic cylinder. 2 to raise the plunger 3 and feed the car 1
To rise.

When the car 1 arrives at the destination floor and stops, the lift control command UC turns off, and in synchronization with this, the lift valve closing signal PENA turns off. After that, in order to reduce the stop shock and equalize the pressures of the hydraulic pump 8 and the hydraulic cylinder 2, the open signal V of the second check valve 14 is passed after a time delay τue1.
Turn off pt, and after a further time delay τue2, first check valve 1
The open signal Vpc of 2 is turned off.

<< Stop Control >> When the stopped state of the car is continued, depending on the amount of oil leaking from the second check valve 14 to the oil tank 10, the hydraulic pump 8 is higher than the pressure on the hydraulic cylinder 2 side. Although the pressure on the side may decrease,
The pressure in the pipe 6 is maintained and controlled based on the timing chart shown in FIG.

From the hydraulic cylinder 2 to the flow control valve 7 by the first pressure sensor 13 and the second pressure sensor 15, respectively.
And the pressure between the flow control valve 7 and the hydraulic pump 8 are monitored, and when a pressure difference occurs between them, the signal PE is turned on, and after the time delay τps1, the second
The check valve 14 open signal Vpt is turned on, and after the time delay τps2, the signal PENA that closes the rising valve of the flow control valve 7 is turned on to throttle the amount of oil flowing back to the oil tank 10 and the pipe 6 side. By supplying oil to the hydraulic pump 8, the pressure on the hydraulic pump 8 side is increased, and the pressure on the hydraulic cylinder 2 side and the pressure on the hydraulic pump 8 side are controlled to be equal.

Then, the first and second pressure sensors 13, 15
When the pressure difference between them disappears, the signal PE is turned off, and in synchronization with this, both the signal Vpt and the signal PENA are turned off, and the pressure control operation is stopped.

Thus, in the hydraulic elevator system according to the first embodiment, the first check valve 12 is provided between the hydraulic cylinder 2 and the hydraulic pump 8, and the hydraulic pump 8 and the oil tank 10 are provided with each other. By providing the second check valve 14 and controlling so that the pressure on the hydraulic cylinder 2 side and the pressure on the hydraulic pump 8 side are always equal pressure when the car 1 is stopped, when the hydraulic pump 8 is restarted. Even if the pressures on the hydraulic cylinder 2 side and the hydraulic pump 8 side are not adjusted, the car 1 can be immediately started without causing vibration, and a highly responsive operation can be performed.

In the above embodiment, the second pressure sensor 1
5 was installed between the flow control valve 7 and the hydraulic pump 8,
The second pressure sensor 15 may be installed anywhere between the first check valve 12 and the second check valve 14.

FIG. 7 shows a second embodiment common to the inventions of claims 1 to 3. In the hydraulic elevator system of this embodiment, the second pressure sensor 15 is connected to the hydraulic pump 8 and the second. It is installed at a position between the check valve 14 and the check valve 14. Therefore, the other structure is the same as that of the first embodiment shown in FIG.

Also in this second embodiment, the pressure on the hydraulic cylinder 2 side and the pressure on the hydraulic pump 8 side are monitored, and when a pressure difference occurs, the hydraulic pump 8 is activated to check the pressure on the hydraulic pump 8 side. It can be raised to compensate for the pressure differential.

According to the first aspect of the present invention, if the check valve has a small amount of leakage or if strict equal pressure control is not required, the equal pressure control function by the pressure sensor and the pump motor is omitted. Therefore, the cost can be reduced, which is advantageous especially when installing in a small building or a private house.

Next, a common embodiment of the inventions of claims 4 to 6 will be described with reference to FIG. The hydraulic elevator system of the third embodiment employs a rotation speed control system, and like the first embodiment, the car 1, the hydraulic cylinder 2, the plunger 3, the pulley 4, the rope 5, the pipe 6, and the hydraulic pressure. Pump 8, electric motor 9, oil tank 10, speed sensor 16
It has. As a characteristic of the rotation speed control system, a check valve for the pressure oil supplied from the hydraulic pump 8 is provided as the first check valve 12, and the relief valve 18 and the electric motor 9 are provided.
Inverter device 19 for performing inverter control of these, check valve 12, relief valve 18 and inverter device 1
A control device 20 for controlling 9 is provided.

Further, in the hydraulic elevator system of this embodiment, the hydraulic pump 8 and the oil tank 1 are the same as in the first embodiment.
A second check valve 14 in the middle of piping between the first pressure sensor 13 and the first check valve 12 for detecting the pressure between the hydraulic cylinder 2 and the first check valve 12; A second pressure sensor 15 for detecting the pressure between the valve 12 and the second check valve 14 is provided.

The above-mentioned control device 20 inputs the speed signal from the speed sensor 16, and the first and second pressure sensors 1
Pressure signals are input from the motors 3 and 15 to control the opening and closing of the first and second check valves 12 and 14 for controlling the speed of the car 1, and to control the inverter device 19 to control the electric motor 9 It controls the rotation speed and is composed of a microcomputer.

Next, the operation of the hydraulic elevator system having the above construction will be described.

<< Descent Operation >> When the descending operation is performed from the stopped state of the car 1, the operation control is performed according to the timing chart of FIG. 2 and the sequence of FIG. 3 as in the first embodiment. However, since the third embodiment uses the rotation speed control method, the inverter control of the rotation speed of the hydraulic pump 8 is performed instead of the control of the flow rate control valve 7, and the signal PENA indicates the operation of the hydraulic pump 8. Read as a signal.

First, when the car 1 is stopped, both the first check valve 12 and the second check valve 14 are closed.
When the descending operation start command DC is issued, the second check valve 1
The open signal Vpt for 4 is turned on after a time delay of τds1 to open the second check valve 14, and the oil between the first check valve 12 and the second check valve 14 becomes an oil tank. It begins to flow to 10. After a time delay of τds2, the first check valve 1
The release signal Vpc for 2 is turned on, and the oil on the hydraulic cylinder 1 side flows out to the oil tank 10 via the first check valve 12. Since the hydraulic pump 8 starts to rotate due to this oil flow, the operation signal PE of the hydraulic pump 8 is delayed after a time delay τds3.
Turn NA on. After that, the flow rate of oil is controlled by controlling the rotation speed of the hydraulic pump 8 by an inverter to control the speed of the car 1.

When the car 1 arrives at the destination floor and stops, the descending control command DC turns off, and in synchronization with this, the operation signal PENA of the hydraulic pump 8 turns off. After that, in order to soften the stop shock and equalize the pressures of the hydraulic pump 8 and the hydraulic cylinder 2, the first check valve 12 is delayed by a time delay τde1.
The open signal Vpc of is turned off, and after the time delay τde2, the second signal
The open signal Vpt of the check valve 14 is turned off.

<< Climbing Operation >> When ascending operation is performed from the stopped state of the car 1, the operation control is performed according to the timing chart of FIG. 4 and the sequence of FIG. 5 as in the first embodiment.

First, when the car 1 is stopped, both the first check valve 12 and the second check valve 14 are closed.
Then, when the ascending operation start command UC is issued, the first check valve 1
The open signal Vpc for 2 is turned on after the time delay of τus1 to open the first check valve 12, and after the time delay of τus2, the open signal Vpt for the second check valve 14 is turned on and the first check valve 12 is turned on. The check valve 14 of No. 2 is opened. Further, after a time delay of τus3, the operation signal PENA of the hydraulic pump 8 is turned on. This time delay τus3 needs to be made as short as possible in order to prevent the reverse flow of oil from the hydraulic cylinder 2 to the oil tank 10. As a result, oil starts to flow into the hydraulic cylinder 2 when the hydraulic pump 8 is activated. Therefore, based on the speed pattern generated by the control device 20, the hydraulic pump 8
The amount of oil discharged from the hydraulic pump 8 is controlled by performing the inverter control of the rotation speed of the above, and the plunger 3 is raised and the car 1 is raised by supplying the oil of the controlled flow rate to the hydraulic cylinder 2. .

When the car 1 arrives at the destination floor and stops, the lift control command UC is turned off, and in synchronization with this, the operation signal PENA of the hydraulic pump 8 is turned off. After that, in order to soften the stop shock and equalize the pressures of the hydraulic pump 8 and the hydraulic cylinder 2, the second check valve 14 is delayed by a time delay τue1.
The open signal Vpt of is turned off, and after the time delay τue2, the first
The open signal Vpc of the check valve 12 is turned off.

<< Stop Control >> When the stopped state of the car is continued, depending on the amount of oil leaking from the second check valve 14 to the oil tank 10, the hydraulic pump 8 is higher than the pressure on the hydraulic cylinder 2 side. Side pressure may decrease, but first
Similarly to the embodiment described above, the pressure in the pipe 6 is maintained and controlled based on the timing chart shown in FIG.

The pressure from the hydraulic cylinder 2 to the first check valve 12 and the first check valve 12 to the second check valve 1 are respectively controlled by the first pressure sensor 13 and the second pressure sensor 15.
The pressures up to 4 are monitored, and when a pressure difference occurs between them, the signal PE is turned on, the opening signal Vpt of the second check valve 14 is turned on after the time delay τps1, and the time delay is further delayed. After τps2, the operation signal PENA of the hydraulic pump 8 is turned on, and the pressure on the hydraulic pump 8 side is increased by replenishing the oil from the oil tank 10 into the pipe 6 to increase the pressure on the hydraulic cylinder 2 side and the hydraulic pump 8 side. Control so that the pressures are equal.

Then, the first and second pressure sensors 13, 15
When the pressure difference between them disappears, the signal PE is turned off, and in synchronization with this, both the signal Vpt and the signal PENA are turned off, and the pressure control operation is stopped.

Thus, in the hydraulic elevator system according to the third embodiment, the first check valve 12 is provided between the hydraulic cylinder 2 and the hydraulic pump 8 and the hydraulic pump 8 and the oil tank 10 are provided with each other. By providing the second check valve 14 and controlling so that the pressure on the hydraulic cylinder 2 side and the pressure on the hydraulic pump 8 side are always equal pressure when the car 1 is stopped, when the hydraulic pump 8 is restarted. Even if the pressures on the hydraulic cylinder 2 side and the hydraulic pump 8 side are not adjusted, the car 1 can be immediately started without causing vibration, and a highly responsive operation can be performed.

In the above embodiment, the second pressure sensor 1
5 is installed between the first check valve 12 and the hydraulic pump 8, the second pressure sensor 15 is provided between the first check valve 12 and the second check valve 14. It can be installed anywhere.

FIG. 9 shows another embodiment common to the inventions of claims 4 to 6, and in the hydraulic elevator system of the fourth embodiment, the second pressure sensor 15 is replaced by the hydraulic pump 8. It is installed at a position between it and the second check valve 14. Therefore, the other structure is the same as that of the third embodiment shown in FIG.

Also in the fourth embodiment, the pressure on the hydraulic cylinder 2 side and the pressure on the hydraulic pump 8 side are monitored, and when a pressure difference is generated, the hydraulic pump 8 is started and the pressure on the hydraulic pump 8 side is adjusted. It can be raised to compensate for the pressure differential.

In the invention of claim 4 as well, if the check valve has little leakage or does not require such strict equal pressure control, the equal pressure control function by the pressure sensor and the pump motor is omitted. Therefore, the cost can be reduced, which is advantageous especially when installing in a small building or a private house.

[0063]

As described above, according to the invention of claim 1,
The pressure between the hydraulic cylinder and the first check valve by adjusting the operation timing of the first check valve and the second check valve by the valve control device when the car is stopped, and the flow control valve Since the pressure between the second check valve and the second check valve is controlled to be equal, the shock at the time of stop is suppressed, and when restarting from the stopped state, the hydraulic cylinder side and the hydraulic pressure are It is not necessary to perform control so that the pressure on the pump side becomes equal to the pressure on the pump side, and the time delay from the generation of the start command until the car actually starts moving can be reduced, and the responsiveness can be improved.

According to the invention of claim 2, in the hydraulic elevator system of the invention of claim 1, the pressure between the hydraulic cylinder and the first check valve, the flow control valve, and the second check valve are further stopped during stoppage. Since the pump motor is controlled by the pressure control device so that the pressure between the check valve and the check valve becomes equal, the hydraulic pump can be used even when leak occurs particularly in the second check valve. Side pressure can be maintained at a predetermined pressure, and when restarting from a stopped state, it is not necessary to control so that the pressures on the hydraulic cylinder side and the hydraulic pump side become equal, The time delay from the generation of the start command until the car actually starts moving can be further reduced, and the responsiveness can be further improved.

According to the invention of claim 3, in the hydraulic elevator system of the invention of claim 2, a first pressure sensor for detecting a pressure between the hydraulic cylinder and the first check valve, and a first pressure sensor. Second pressure sensor that detects the pressure between the check valve and the second check valve, and the pressure control device performs equal pressure control based on the pressure detection values of the first and second pressure sensors. Therefore, the pressures on the hydraulic cylinder side and the hydraulic pump side can be controlled to be exactly equal.

According to the fourth aspect of the present invention, when the car is stopped, the valve control device adjusts the operation timings of the first check valve and the second check valve to adjust the hydraulic cylinder and the first check valve. Since the pressure between the stop valve and the pressure between the first check valve and the second check valve are controlled to be equal pressure, shock at the time of stop is suppressed, Also, when restarting from a stopped state, it is not necessary to control so that the pressures on the hydraulic cylinder side and hydraulic pump side become equal, and there is a time delay from the generation of the start command until the car actually starts moving. It can be reduced and the responsiveness can be improved.

According to the invention of claim 5, in the hydraulic elevator system of the invention of claim 4, the pressure between the hydraulic cylinder and the first check valve and the first check valve are further activated during stoppage. Since the pump motor is controlled by the pressure control device so that the pressure between the second check valve and the second check valve becomes equal, in particular, when a leak occurs in the second check valve. Can also maintain the pressure on the hydraulic pump side to a predetermined pressure, and when restarting from a stopped state, it is not necessary to control so that the pressures on the hydraulic cylinder side and hydraulic pump side become equal. The time delay from the generation of the start command to the actual movement of the car can be further reduced, and the responsiveness can be further improved.

According to the invention of claim 6, in the hydraulic elevator system of the invention of claim 5, there is further provided a first pressure sensor for detecting a pressure between the hydraulic cylinder and the first check valve, and a first pressure sensor. Second pressure sensor that detects the pressure between the check valve and the second check valve, and the pressure control device performs equal pressure control based on the pressure detection values of the first and second pressure sensors. Therefore, the pressures on the hydraulic cylinder side and the hydraulic pump side can be controlled to be exactly equal.

[Brief description of drawings]

FIG. 1 is a system diagram of a common embodiment of the inventions of claims 1 to 3.

FIG. 2 is a timing chart showing the descending operation control of the above embodiment.

FIG. 3 is a sequence diagram showing the descending operation control of the above embodiment.

FIG. 4 is a timing chart showing the rising operation control of the above embodiment.

FIG. 5 is a sequence diagram showing the rising operation control of the above embodiment.

FIG. 6 is a timing chart showing pressure control at the time of stop in the above embodiment.

FIG. 7 is a system diagram of another embodiment common to the inventions of claims 1 to 3.

FIG. 8 is a system diagram of a common embodiment of the inventions of claims 4 to 6;

FIG. 9 is a system diagram of another embodiment common to the inventions of claims 4 to 6;

[Explanation of symbols]

 1 Car 2 Hydraulic cylinder 3 Plunger 4 Pulley 5 Rope 6 Piping 7 Flow control valve 8 Hydraulic pump 9 Electric motor 10 Oil tank 11 Control device 12 First check valve 13 First pressure sensor 14 Second check valve 15 Second pressure sensor 16 Speed sensor 17 Guide rail 18 Relief valve 19 Inverter device 20 Control device

Claims (6)

[Claims] 1. A hydraulic cylinder for raising and lowering a car, a hydraulic pump for passing pressurized oil to the hydraulic cylinder, an oil tank for retaining oil, and a hydraulic pump for raising the car. A flow rate control valve for controlling the flow rate of oil sucked up from an oil tank and supplied to the hydraulic cylinder, and the flow rate of oil recirculated from the hydraulic cylinder to the oil tank during the descent operation of the car;
A hydraulic elevator apparatus of a flow rate control system, comprising: a pump electric motor for driving the hydraulic pump; a first check valve installed in a pipe between the hydraulic cylinder and the hydraulic pump; and the oil tank. A second check valve installed in the middle of piping between the hydraulic pump and a pressure between the hydraulic cylinder and the first check valve when stopped, the first check valve and the second check valve A hydraulic elevator device comprising: a valve control device that controls operation timings of the first and second check valves so that the pressure between the stop valve and the stop valve becomes equal. 2. The hydraulic elevator system according to claim 1, further comprising a pressure between the hydraulic cylinder and the first check valve during stoppage, the first check valve and the second check valve. And a pressure control device that controls the pump motor so that the pressure between the pressure and the pressure is equal. 3. A first pressure sensor for detecting the pressure between the hydraulic cylinder and the first check valve, and a pressure between the first check valve and the second check valve. 3. A hydraulic elevator system according to claim 2, further comprising a second pressure sensor for detecting, wherein the pressure control device controls the equal pressure based on the pressure detection values of the first and second pressure sensors. 4. A hydraulic cylinder for raising and lowering a car, a hydraulic pump for allowing pressurized oil to pass through the hydraulic cylinder, an oil tank for retaining oil, a pump electric motor for driving the hydraulic pump, and A rotation speed control type hydraulic elevator device comprising an inverter device for performing variable speed control of a pump motor, comprising: a first check valve installed on the way of piping between the hydraulic cylinder and the hydraulic pump; A second check valve installed on the way between the oil tank and the hydraulic pump, the pressure between the hydraulic cylinder and the first check valve when stopped, the first check valve, and the first check valve. And a valve control device that controls the operation timings of the first and second check valves so that the pressure between the first and second check valves is equal. 5. The hydraulic elevator system according to claim 4, further comprising the pressure between the hydraulic cylinder and the first check valve during stoppage, the first check valve and the second check valve. And a pressure control device that controls the pump motor so that the pressure between the pressure and the pressure is equal. 6. A first pressure sensor for detecting a pressure between the hydraulic cylinder and a first check valve, and a pressure between the first check valve and a second check valve. 6. A hydraulic elevator apparatus according to claim 5, further comprising a second pressure sensor for detecting, wherein the pressure control device performs equal pressure control based on pressure detection values of the first and second pressure sensors.