JP2560587B2 - Oil temperature rise operating device for hydraulic elevator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for increasing the oil temperature of a hydraulic elevator when the oil temperature is lowered.

[0002]

2. Description of the Related Art Conventionally, hydraulic control systems for hydraulic elevators include a flow control valve system, a pump control system, a motor rotation speed control system, and the like. The flow rate control valve system rotates the electric motor at a constant induction speed when rising, returns a constant discharge amount of oil from the hydraulic pump to the oil tank, and when the start command is issued, the flow rate control valve controls the amount of oil to be returned to the oil tank. The speed of the car is controlled by adjusting. When the car descends, the car's speed is controlled by adjusting the car's descent due to its own weight with a flow control valve.

In this system, extra oil is circulated when rising, and potential energy is consumed for heat generation of oil when descending, so energy loss is large and oil temperature rises significantly.
As a method of compensating for this drawback, there are a pump control method and an electric motor rotation speed control method as a method of sending only a necessary oil temperature when rising and regeneratively braking the electric motor when lowering.

The pump control system uses a variable displacement pump, and the discharge amount of the pump itself is variable by the control device, and the structure of the control device and the pump is complicated and expensive.

On the other hand, in recent years, with the technological progress of semiconductors, a method of controlling the rotation speed of an induction motor over a wide range by changing a voltage and a frequency via an inverter has been considered. It is a speed control system, which uses a constant discharge type pump and variably controls the discharge amount of the pump by changing the rotation speed of the electric motor, and is expected to be inexpensive and highly reliable.

After the hydraulic elevator has been stopped for a long time, or after the winter season, the oil temperature is lowered, so that a function is provided to raise the oil temperature. The oil temperature increasing operation as shown in Japanese Patent Publication No. 209484 is performed. This is because a branch flow path is provided on the discharge side of the hydraulic pump, and a solenoid valve is placed in this, and when a decrease in oil temperature is detected, the electric motor is driven, and the solenoid valve is switched to flow oil to the branch flow path. The oil is returned to the tank and the oil temperature is raised by the resistance of the flow rate.

[0007]

In the conventional oil temperature rising operating device for a hydraulic elevator as described above, when the oil temperature drop is detected, the electric motor is driven to recirculate the oil. If the ascending operation is performed for a long time, the time during which the current flows through the inverter is inevitably long, and there is a risk that the inverter may be destroyed due to heat generation or the like. Also, as the oil temperature decreases, the viscosity of the oil increases
Torque shortage occurs. As a result, there is a problem in that it is necessary to increase the capacity of the inverter part.

The present invention has been made to solve the above problems, and is a hydraulic elevator capable of performing an oil temperature increasing operation without destroying the inverter portion and with an inverter capacity that can sufficiently withstand normal elevator control. It is an object of the present invention to provide an oil temperature raising operation device of

[0009]

According to a first aspect of the present invention, an oil temperature rising operation device for a hydraulic elevator is provided with a command circuit for intermittently operating an electric motor during oil temperature rising operation.

Also, the oil temperature rising operation device for a hydraulic elevator according to the second invention is the motor of the first invention, wherein the maximum value of the control pattern during the oil temperature rising operation corresponds to the rated speed of the car. It is set to a value smaller than the speed.

Further, an oil temperature raising operation device for a hydraulic elevator according to a third aspect of the present invention is the same as that of the first aspect, wherein the control pattern during the oil temperature raising operation is set to a multi-step acceleration pattern.

[0012]

In the first aspect of the present invention, the electric motor is intermittently operated to increase the oil temperature, and in the second aspect, the maximum value of the control pattern during the oil temperature increasing operation corresponds to the rated speed of the car. Since the control pattern is set to a multi-step acceleration pattern in the third aspect of the invention, heat generation of the inverter is suppressed.

[0013]

1 to 4 are views showing an embodiment of the present invention, FIG. 1 is an overall configuration diagram, FIG. 2 is a block diagram of a speed control device, FIG. 3 is a control pattern curve diagram, and FIG. It is an oil temperature rise driving circuit diagram, and the same code shows the same part.

In FIG. 1, (1) is a hoistway and (2) is a hoistway.
Cylinder embedded in pit of (1) and filled with hydraulic oil (3), (4) is a plunger supported by hydraulic oil (3), (5)
Is a car provided on the top of the plunger (4), and (6) is an electromagnetic switching valve that always functions as a check valve and is switched when the coil (6A) is energized to conduct in the reverse direction. A pipe (7) connects the electromagnetic switching valve and the cylinder (2).

(8) is a hydraulic pump driven by a three-phase induction motor (9) and capable of reversible rotation, and (10) is a speed detector for detecting the rotation speed of the electric motor (9) and outputting a speed signal (10a). , (11) is a tube
An oil tank connected to the hydraulic pump (8) via (12) to send and receive pressure oil (3), (13) detects the oil temperature of the oil tank (11), and when this falls below a predetermined value, an oil temperature signal An oil temperature detector that outputs (13a), (14) a pipe that connects the hydraulic pump (8) and the electromagnetic switching valve (6), and (15) a branch that connects the pipe (14) and the oil tank (11). Tube, (1
6) is an electromagnetic switching valve that is installed in the branch pipe (15) and normally closes the branch pipe (15) and opens when the coil (16A) is energized to allow bidirectional conduction, and (17) is the pipe (14) The pressure signal (1
It is a pressure sensor that outputs 7a).

R, S, T are three-phase AC power supplies, (21) is a rectifying circuit for converting three-phase AC into DC, (22) is a smoothing capacitor for smoothing the output of the rectifying circuit (21), and (23) is An inverter that converts direct current into three-phase alternating current of variable voltage and variable frequency by pulse width modulation control, (24) is a regenerative inverter that returns direct current to alternating current power supplies R, S, T, and (25) is a speed control device. Control signal (2
Output 5a) to the inverter (23). (30a) to (30d) are shown in Fig. 4.
It is a contact point of the motor control relay (30) shown in.

In FIG. 2, (41U) is an ascending traveling pattern generation circuit for generating an ascending traveling pattern for ascending the car (5) shown by a broken line in FIG. 3, and (41D) is a descending traveling pattern for similarly generating a descending traveling pattern. Generator circuit, (42a) and (42b) are upward contacts that are closed during upward operation, (43a) and (43b) are downward contacts that are closed during downward operation, and (45) is a hydraulic pump.
A bias pattern generation circuit that issues a command to rotate the hydraulic pump (8) at a rotation speed corresponding to the leakage amount of (8), and (46) is an adder.

(47) is the oil temperature rise pattern shown by the solid line in FIG.
(47a) oil temperature rise pattern generation circuit, (48) adder, (49) conversion circuit for converting the speed signal (10a) to the same voltage level as the pattern signal, (50) adder, ( 51) is a transmission circuit that transmits the input with a predetermined amplification degree, (52) is an adder that outputs the frequency command signal ω ₀ , and (53) is a linear voltage command signal V with respect to the frequency command signal ω ₀ . A function generating circuit for outputting, (54) is a reference sine wave generating circuit for outputting a control signal (25a) based on the frequency command signal ω ₀ and the voltage command signal V.

In FIG. 4, (+) and (-) are DC power supplies, and (13b)
Is a low temperature detection contact indicating the function of the oil temperature signal, (30) is a motor control relay, (42c) is an upward contact that opens during an upward operation period, (42d) is an upward contact that closes the same, (43c) Is a downward contact that opens during the downward operation period, (43d) is a downward contact that is also closed, (61) is an oil temperature rise command relay, and (61a) ~
(61c) is the normally open contact.

(62) is an oil temperature rise pattern command relay,
2a) (62b) is its normally open contact, (62c) is the same normally closed contact, (6
(3) is a time-delay type stop time relay, (63a) (63b) is its normally closed contact, (63c) (63d) is a normally open contact, and (64) is also a time-delay type start time relay. 64a) (64b) is its normally open contact,
(64c) is also a normally closed contact.

Next, the operation of this embodiment will be described. Now, if the car (5) is stopped and a call in the ascending direction occurs, the car (5) closes the door, and when the door is closed, a start command is issued and the contact (42d) in FIG. 4 is closed. Motor Control Relay (30)
Is energized, the contacts (30a) to (30c) are closed, and the motor (9)
Is connected to the inverter (23). Further, since the contact point (30d) is also closed, the bias pattern generation circuit (45) generates a bias pattern. After a predetermined time, the ascending travel pattern (41Ua) is generated from the ascending travel pattern generation circuit (41U). At this time, since the upward contacts (42a) (42b) are closed, both patterns are added by the adder (46), and the adder (4
After 8) (the oil temperature rise pattern (47a) is zero), it is input to the adder (50).

The adder (50) collates with the speed signal (10a),
The deviation is added to the speed signal (10a) by the adder (52) to become the frequency command signal ω ₀ . Further, a voltage command signal V is output from the function generator (53). Reference sine wave generator (54)
Outputs a control signal (25a) based on both signals ω ₀ and V so that a three-phase alternating current of a sine wave is output from the inverter (23).

With this, the electric motor (9) drives the hydraulic pump (8), and the oil in the oil tank (11) is transferred to the pipe (12), the hydraulic pump (8),
Cylinder (2) through pipe (14), electromagnetic switching valve (6) and pipe (7)
The car (5) is pumped inside and the car (5) travels up as much as the amount of oil. In addition, the electromagnetic switching valve (6) is energized during descent operation (circuit omitted), and the descent travel pattern generation circuit (41D)
A downward traveling pattern symmetrical to the upward traveling pattern is generated, the electric motor (9) rotates in the reverse direction, and the car (5) travels downward.

[0024] Here, for example, for a long period of suspension of operation,
When the oil temperature falls below a predetermined value, the oil temperature signal (13a) from the oil temperature detector (13) in the oil tank (11) becomes "H", and the low temperature detection contact (13b) is closed. At this time, no operation command by the identification, the upward and downward directions Proximity (42c) (43c) is closed, the oil temperature rises Operation Command (61) is energized,
The contacts (61a) to (61c) are closed.

When the contact (61a) is closed, (+)-(63a)-(61
By the circuit of a)-(62)-(-), the oil temperature rise pattern command relay (62) is energized and the contacts (62a) (62b) are closed. contact
The closing of (62a) energizes the motor control relay (30) and closes the contacts (30a) to (30d).
(9) is connected to the inverter (23).

Then, (11)-(12)-(8)-(14)-(15)-
The circular flow path of (16)-(11) is established. On the other hand, in the oil temperature rise pattern generation circuit (47), the oil temperature rise pattern (47
a) gradually increases (between time (a) and (b) in FIG. 3), and accelerates to a predetermined rotation speed with the same magnitude as the ascending traveling pattern (41 Ua) (time (b) and (c) in FIG. 3). while). Then, the climbing pattern (41U
It becomes a constant speed smaller than the maximum value of a) (time (c) in Figure 3)
(Between (d)). After this elapses a predetermined time, the pattern value decreases (between time (d)-(e) in FIG. 3). In this way, since the acceleration of the oil temperature increase pattern (47a) is moderated, the pressure oil does not push up the check valve of the electromagnetic switching valve (6) to push up the car (5).

Now, when the contact (62b) is closed, (+)-(62
b)-(61b)-(63)-(-) circuit, stop time relay (6
3) is energized and the time (between time (a) and (e) in FIG. 3) during which the oil temperature increase pattern (47a) is generated elapses, the contact (63c) closes and self-holds. Also, the contact (63a) opens.
This deactivates the oil temperature rise pattern command relay (62),
Since the contact (62a) is opened, the electric motor control relay (30) is deenergized, so that the command to the inverter (23) and the coil (16A) of the electromagnetic switching valve (16) is cut off. Therefore, the electric motor (9)
Is stopped, and the electromagnetic switching valve (16) closes the reflux circuit.

On the other hand, since the contact (63d) is closed and the contact (63b) is opened, the start time relay (64) is formed by the (+)-(63d)-(62c)-(64)-(-) circuit. ) Is energized, and after a lapse of a predetermined time, the contact (64b) closes and self-holds. Further, since the contact (64a) is closed, the oil temperature increase pattern command relay (62) is energized again, and the oil temperature increase operation is restarted. Then, the contact (62
When c) opens and then the contact (63b) opens, the start timed relay (64) is de-energized. In this way, the oil temperature increasing operation continues intermittently.

When the oil temperature rises due to the oil temperature rise operation and the oil temperature signal (13a) becomes "L", the low temperature detection contact (13b) is opened and the oil temperature rise operation command relay (61) is deenergized. Contact (61
a) to (61c) are opened and the oil temperature rise pattern command relay (6
2), the stop and start timed relays (63) and (64) are deenergized, and the oil temperature increasing operation ends.

[0030]

As described above, in the first invention of the present invention, the electric motor is intermittently operated to increase the oil temperature, and in the second invention, the maximum value of the control pattern during the oil temperature increasing operation is set to the maximum value of the car. Since it is set to a value smaller than the motor speed corresponding to the rated speed, and in the third invention, the control pattern is set to a multi-step acceleration pattern, heat generation of the inverter is suppressed,
This has the effect of preventing damage to the inverter due to heat generation without increasing the capacity of the inverter.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing the speed control device of FIG.

FIG. 3 is a control pattern curve diagram of FIG.

FIG. 4 is an oil temperature increasing operation circuit diagram showing an embodiment of the present invention.

[Explanation of symbols]

 2 Cylinder 3 Hydraulic oil 5 Cage 8 Hydraulic pump 9 Three-phase induction motor 13 Oil temperature detector 15 Branch pipe 16 Electromagnetic switching valve 23 Inverter 25 Speed controller 47 Oil temperature rise pattern command circuit 62 Oil temperature rise pattern command relay 63 Intermittent operation Command circuit (stop timed relay) 64 Intermittent operation command circuit (start timed relay)

Claims (3)

(57) [Claims] 1. A hydraulic pump for controlling the amount of hydraulic oil supplied to and discharged from a hydraulic cylinder for raising and lowering a car, and an electric motor for driving the hydraulic pump and controlled at a variable speed by an inverter. In a hydraulic elevator for instructing an oil temperature increase operation for driving the electric motor to recirculate the hydraulic oil when a temperature decrease is detected, a command circuit for intermittently operating the electric motor during the oil temperature increase operation is provided. An oil temperature rise operation device for a hydraulic elevator. 2. A hydraulic pump for controlling a supply / discharge amount of hydraulic oil to / from a hydraulic cylinder for raising / lowering a car, and an electric motor for driving the hydraulic pump and variably controlled by an inverter according to a predetermined control pattern. In a hydraulic elevator that commands an oil temperature increase operation that drives the electric motor to recirculate the hydraulic oil when a decrease in the oil temperature of the hydraulic oil is detected, the maximum value of the control pattern during the oil temperature increase operation is set to the car. Is set to a value smaller than the speed of the electric motor corresponding to the rated speed of. 3. A hydraulic pump for controlling the amount of hydraulic oil supplied to and discharged from a hydraulic cylinder for raising and lowering a car; and an electric motor for driving the hydraulic pump and variably controlled by an inverter according to a predetermined control pattern. In the hydraulic elevator for commanding an oil temperature increase operation for driving the electric motor to recirculate the hydraulic oil when a decrease in the hydraulic temperature of the hydraulic oil is detected, the control pattern is set to a multi-step acceleration pattern. Oil temperature rise operation device for hydraulic elevator.