JPS636470B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed control device for a hydraulic elevator, and in particular, it is configured to save energy and achieve stable running by selectively using open control and closed loop control according to a speed command pattern. The present invention relates to a speed control device for a hydraulic elevator.

The hydraulic elevator speed control device is configured as a hydraulic servo mechanism that controls the speed of the elevator using an electric control section and a hydraulic control section.

A conventional speed control device for this type of hydraulic elevator opens and closes a solenoid valve using a limit switch that engages with a car that moves up and down along a guide rail and opens and closes it. This controls the opening degree of the elevator (valve), thereby controlling the elevator's elevating and descending operations from start to stop using a sequence control method. In this case, acceleration,
The deceleration and landing operations were controlled purely hydraulically by throttle chokes provided on the inlet and outlet sides of the control chamber (pressure chamber) of the flow rate control valve. Such conventional speed control devices have the disadvantage that acceleration, deceleration, and landing operation time vary significantly due to changes in oil viscosity due to oil temperature and changes in load pressure due to load, and high power consumption. be.

On the other hand, as an effective control method for energy saving, there is a speed servo mechanism that detects the speed of the elevator, compares the detected speed with a speed command, and controls the solenoid valve and flow control valve based on the deviation output signal. Proposed. In this conventional speed servo mechanism, during upward operation, an overspeed command is given during acceleration and during full speed running to completely close the flow control valve and saturate the speed servo. Further, from the deceleration start point following this, speed feedback control is performed to configure a normal speed servo. In such conventional speed control devices, the speed servo mechanism has a response delay, so if feedback control is performed during acceleration or full-speed running, an impactful vibration load is generated at the beginning of acceleration or full-speed running. This has the disadvantage that stable running cannot be achieved due to the addition of Although this vibration load attenuates after a certain period of time, there is a problem in that it gives a very unpleasant feeling due to noise and shock during startup operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide an elevator speed control device that eliminates the drawbacks of the prior art as described above and is effective in energy saving and provides stable running with little vibration.

The present invention is directed to a speed control device that compares the speed of an elevator with a speed command and electrically and hydraulically controls a flow control valve. Through control, stable running is ensured,
On the other hand, during deceleration, floor landing operation, and stop, closed loop control is performed to keep the deceleration and floor landing operating speed constant, thereby providing stable elevator speed control that is effective for energy saving and has little vibration.

The present invention provides a speed control device for a hydraulic elevator that includes a hydraulic servo mechanism that controls the speed of the elevator using an electrical control section and a hydraulic control section.
A speed command means for generating a speed command signal in accordance with an elevator speed command pattern, a speed sensor for detecting the actual speed of the elevator, and a comparator for comparing a feedback signal emitted from the speed sensor with the speed command signal. , a flow control valve whose opening degree is adjusted by the signal from this comparator, a cylinder whose pressurized oil flow rate is controlled by this flow control valve and which changes the speed of the elevator, and the fact that the elevator car has reached the deceleration position. A deceleration command limit switch detects that the elevator car has reached the stop position and issues a deceleration command signal, a stop command limit switch detects that the elevator car has reached the stop position and issues a stop command signal, and a stop command limit switch that turns on in response to the deceleration command signal and generates a stop command signal. and a relay provided in a circuit for transmitting the feedback signal, which turns off in response to the feedback signal.

That is, according to the present invention, in a speed control device for a hydraulic elevator equipped with a hydraulic servo mechanism that controls the speed of the elevator using an electric control section and a hydraulic control section, oil is controlled based on a speed command during acceleration and full speed operation from startup. Open control is performed to control the opening degree of the oil quantity control valve, and the detected speed of the elevator is compared with the speed command during deceleration start, deceleration, and landing operation, and the opening degree of the oil quantity control valve is adjusted based on the deviation output. A speed control system for a hydraulic elevator is provided which is characterized by limited closed loop control.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a push button 37 is installed in an elevator car 1 that moves up and down along a guide rail 4. A ram 2 is fixed below the car 1 and fitted into a cylinder 3. Therefore, the elevator car 1 is raised or lowered by changing the amount of oil in the cylinder 3. Further, by operating the push button 37 to start, the motor start signal 3
5 is input to an electric motor 9, and the electric motor 9 drives a hydraulic pump 10. On the other hand, the push button 37
From then on, the speed command start signal 36 becomes the speed command 30.
is entered and activated.

The car 1 is provided with a cam 6, and this cam 6
This actuates a deceleration command limit switch 7 and a stop command limit switch 8 installed in the building. Further, a speed sensor 5 is provided at the top of the car 1, and a signal of the detected speed of the elevator is supplied to a comparator 42 via a relay 34. That is, the detected speed of the elevator is fed back to the comparator 42 as a feedback signal 31.

On the other hand, the deceleration command signal 40 from the deceleration command limit switch 7 is supplied to the speed command 30 to generate a command signal for deceleration operation in the speed command pattern of the speed command. Further, a signal from the stop command limit switch 8 is similarly input to the speed command 30 as a stop command signal 41, and a stop command is sent to the comparator 42. Note that the deceleration command signal 40 and the stop command signal 41 are also supplied to the relay 34, and the relay 34 receives the deceleration command signal 40, turns on, and then outputs the stop command signal 41. It operates so that it turns off when it is received. That is,
During deceleration and floor landing operation from the start of deceleration, the detected speed signal 31 of the elevator is supplied to the comparator 42, and the comparator 42 compares the speed detection signal from the speed sensor 5 with the speed command signal from the speed command 30. and is configured to perform closed loop control. In other operating states, ie, during startup, acceleration, and full-speed operation, the relay 34 is in an OFF state, so the feedback signal 31 from the speed sensor 5 is not supplied to the comparator 42. That is, open control is performed.
The output from the comparator 42 is supplied via the amplifier 32 to the magnet 29 of the proportional solenoid valve 23 as a control current 33. The amplifier 32 is a comparator 42
This is for amplifying the deviation output between the speed command signal and the feedback signal from.

Each of the parts described above with reference to FIG. 1 shows an example of the configuration of the electrical control part of the elevator speed control device of the present invention.

Next, the configuration of the hydraulic control section of the illustrated speed control device for a hydraulic elevator according to an embodiment of the present invention will be described.

The oil 39 in the tank 11 is pumped up through the suction strainer 12 by the pump 10 driven by the electric motor 9, and the pump discharge pressure is increased.
It is discharged into the bleed pipe line 13 as _P1 . The bleed line 13 is connected to the load pressure Pc inside the cylinder 3 via a main pipe 15. However, a check valve 24 is provided in the middle of the main pipe 15 and is biased in the valve closing direction by a spring 25 with a predetermined spring force. Therefore, in a normal state, the main pipe 15 is shut off, and only when the check valve 24 opens, a flow rate corresponding to the opening degree flows into or out of the cylinder 3, and the ram 2 The height of the elevator car 1, i.e. the movement of the elevator car 1, is controlled. The bleed line 13
is connected to the return line 14 via a flow rate control valve (speed control valve) 16. This return pipe 14 is a passage for returning return oil into the tank 11.
The oil amount control valve 16 has a pressure chamber (control chamber) 17 formed on one side (upper side) thereof.
A control pressure P ₂ is applied within 7. Note that S ₂ indicates a pressure receiving area on the control pressure side of the control pressure P ₂ .

A tapered portion having a pressure-receiving area _S1 on the throttle side is formed on the other side of the oil amount control valve 16, and the oil amount control valve 16 itself is biased by a spring 18 in a direction to open the bleed pipe 13. ing.

The proportional solenoid valve 23 includes a plunger 28 whose position is controlled in proportion to the value of the control current supplied to the magnet 29, and a flapper 27 formed at the tip of the plunger 28.
When current is supplied to the magnet 29, the flapper 27 moves in the direction of closing the end face of the nozzle 26, and resists the outflow from the nozzle 26 (the nozzle 26
pressure in the pipe (pilot pipe 21) leading to
control. The nozzle 26 communicates with the bleed line 13 via a pilot line 21, a pilot line 20 and a restriction 19. Further, the nozzle 26 is connected to the pilot conduit 2.
1 and a pilot pipe 22 to a pressure chamber (control chamber) of the oil amount control valve 16.

The illustrated speed control device for a hydraulic elevator according to an embodiment of the present invention includes a hydraulic servo mechanism configured by an electric control section and a hydraulic control section as described above. Applied to speed control during driving.

The operation of the illustrated embodiment will be described below.

When the push button 37 in the car 1 is pressed, the electric motor 9 is activated and the pump 10 is rotated, and the oil 39 in the tank 11 is discharged from the pump 10. At the moment of startup, all of the oil discharged from the pump 10 flows through the throttle part _S1 of the oil amount control valve 16 in the fully open state and returns to the tank 11, that is, in a bleed-off state.

The speed command start signal 36 is generated by the starting operation.
is supplied to the speed command 30, the command signal supplied from the speed command to the comparator 42 gradually increases,
This is the control current 33 amplified by the amplifier 32.
It is supplied to the proportional solenoid valve 23 as the proportional solenoid valve 23. That is, a control current proportional to the speed command 30 is supplied to the proportional solenoid valve 23, and in response, the gap between the nozzle 26 in the solenoid valve 23 and the flapper 27 decreases, and the gap in the pilot pipes 21, 22 decreases. control pressure of
P ₂ rises, and the pressure (control pressure) P ₂ in the pressure chamber (control chamber) 17 of the oil amount control valve 16 increases. When the control pressure _P2 increases, the oil flow control valve 1
6 moves in the closing direction, ie, downward in FIG. 1, to throttle the bleed flow rate from the bleed pipe line 13. When the bleed flow rate is throttled, the pressure _P1 on the discharge side of the pump 10 increases due to the load pressure Pc in the cylinder 3, and a part of the bleed flow rate is transferred to the check valve 24.
is pushed open and flows into the cylinder 3, and the elevator car 1 is accelerated.

When the value of the speed command 30 reaches a certain value after the acceleration period of the speed command 30, that is, the period in which the speed command 30 tends to increase, the oil amount control valve 16 is completely closed, and the entire amount of discharge from the pump 10 is reduced. cylinder 3
and the elevator car 1 is in full speed operation. This full-speed operating state continues while the value of the speed command 30 maintains a constant peak value, and continues until the deceleration command limit switch 7 is actuated by the cam 6 of the car 1 and the deceleration command signal 40 is transmitted. .

Since the deceleration command signal is not yet issued during the acceleration operation and full speed operation after the start, the relay 34 is in an OFF state. That is, during acceleration and full-speed operation from startup, the opening degree of the oil amount control valve 16 is controlled based on the speed command 30, and so-called open control is performed.

When the elevator car 1 reaches the deceleration position, the cam 6 installed in the car 1 activates the deceleration limit switch 7.
make it work. When the deceleration limit switch 7 is turned on, the speed command begins to gradually decrease, and at the same time, the relay 34 is turned on and the speed feedback signal 31 from the speed sensor 5 is supplied to the comparator 42. The deviation output from the comparator 42, that is, the deviation output between the feedback signal 31 from the speed sensor 5 and the speed command 30, is supplied to the proportional solenoid valve 23 via the amplifier 32 as a control current 33. This closed-loop control allows
The control current 33 of the proportional solenoid valve 23 gradually decreases,
Along with this, the control pressure _P2 also decreases, and the oil amount control valve 16, which had been completely closed, gradually moves in the direction of opening (upward in FIG. 1). In this way, a part of the amount of discharged oil that has been flowing into the cylinder 3 up to now is bled off via the oil amount control valve 16, and the amount of oil supplied to the cylinder 3 is reduced, and the amount of oil supplied to the cylinder 3 is reduced. Climb speed is reduced. The speed is decelerated by closed-loop control according to the speed command pattern of the speed command 30, and as a result, when the elevator ascending speed decreases to a value commensurate with the landing speed, the opening degree of the oil amount control valve 16 changes to match the landing speed of the car 1. The bed speed is controlled to remain constant. That is, during the operation at this bed landing speed (bed landing operation), most of the discharge amount from the pump 10 is bled off through the oil amount control valve 16, which is in a relatively large opening state, and a small amount of the discharge amount is The state in which the amount of oil is supplied into the cylinder 3 via the check valve 24 continues, and under this state, landing operation is performed at a constant low speed.

Then, when the car 1 reaches the stop position, the cam 6 operates the stop limit switch 8, and at the same time the speed command 30 is made zero. Therefore, the value of the control current 33 to the proportional solenoid valve 23 also becomes zero, the gap between the nozzle 26 and the flapper 27 increases, and the control pressure P ₂ in the pressure chamber 17 (control chamber) of the oil amount control valve 16 increases. becomes almost zero, and the oil amount control valve 16 becomes fully open. Therefore, the entire amount of oil discharged from the pump 10 is bled off to the tank 11, and no oil is supplied into the cylinder 3, so the car 1 stops.

According to the embodiment of the present invention described above, when the elevator is in ascending operation, the open control is performed by controlling the opening degree of the oil amount control valve based only on the speed command from startup to acceleration and when running at full speed, so vibrations are reduced. Therefore, stable elevator running characteristics with less noise can be obtained. Furthermore, during deceleration operation and floor landing operation from the start of deceleration, closed loop control is performed in which the detected speed of the elevator is compared with the speed command and the opening degree of the oil amount control valve is controlled based on the deviation output. The speed and landing operation speed can be accurately controlled, and by maintaining these at constant values, the speed of the elevator can be controlled with excellent energy savings.

In other words, if the elevator speed is controlled by completely open control, when the oil temperature is high, the amount of bleed-off oil from the oil amount control valve 16 increases, and when the oil temperature becomes low, the viscosity increases and the landing speed decreases. Due to the change in the characteristics of the hydraulic oil as the temperature increases, there is a disadvantage that a deviation of 5 to 6 seconds occurs in the upward operation of the elevator. This results in problems such as a longer motor rotation period and oil leakage, which increases power consumption due to these losses, which is contrary to energy conservation.

On the other hand, if the elevator speed is controlled in a closed loop over the entire range, as mentioned above, vibrations and shocks will increase during acceleration and full speed operation, causing discomfort and reducing durability. There is a problem that power consumption increases, which goes against energy conservation.

The present invention aims to provide a control device for a hydraulic elevator that has excellent energy-saving effects and is capable of stable operation by skillfully combining closed-loop control and open control for elevator speed control. .

As is clear from the above description, according to the present invention, a speed control device for a hydraulic elevator can be obtained which is excellent in energy-saving effects and can perform stable ascending operation.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of a speed control device for a hydraulic elevator according to the present invention. 1...Elevator car, 5...Elevator speed sensor, 7...Deceleration command limit switch,
8... Stop command limit switch, 9... Electric motor, 10... Pump, 13... Bleed pipe, 1
5... Main pipe, 16... Oil amount control valve (speed control valve),
17... Pressure chamber (control room), 23... Proportional solenoid valve, 24... Check valve, 30... Speed command, 31... Feedback signal, 33... Control current, 34... Relay, 35... Motor Start signal, 36...Speed command start signal, 42...Comparator.

Claims (1)

[Claims] 1. A speed control device for a hydraulic elevator equipped with a hydraulic servo mechanism that controls the speed of an elevator using an electric control section and a hydraulic control section, comprising a speed command means for generating a speed command signal according to a speed command pattern of the elevator; a speed sensor that detects the actual speed of the speed sensor, a comparator that compares the feedback signal emitted from the speed sensor with the speed command signal, and a flow control valve whose opening degree is adjusted by the signal from the comparator. , a cylinder that changes the speed of the elevator by controlling the flow rate of pressure oil by this flow control valve, a deceleration command limit switch that detects when the elevator car has reached the deceleration position and issues a deceleration command signal, and a deceleration command limit switch that detects when the elevator car has reached the deceleration position and issues a deceleration command signal, and when the elevator car reaches the stop position. a stop command limit switch that detects that the deceleration has been reached and issues a stop command signal; and a stop command limit switch that is turned on in response to the deceleration command signal and turned off in response to the stop command signal, and is provided in a circuit that transmits the feedback signal. A speed control device for a hydraulic elevator, comprising a relay.