JPS594352B2 - elevator control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a control device for a DC elevator.

In the so-called Ward Leonard method, in which the voltage applied to a DC motor for driving an elevator is changed by a motor generator to change the speed of the DC motor, the field voltage of the motor generator is generally controlled by a voltage control device. It is being said.

One way to construct such a control device at low cost is to limit the output of the voltage control device to one polarity, and when an output in the opposite direction is required, reverse the polarity using a relay contact. It has been proposed.

An example of an elevator control device using this method is shown in FIGS. 1 and 2.

In the figure, 1 is a speed command signal generator that generates a speed command signal 2 for the elevator, 3 is an adder that adds the speed command signal 2 and a speed signal 4 proportional to the speed of the elevator, and 5 is the output of this adder 3. is human-powered, and as mentioned above, the voltage control device whose output has only one-way polarity (only one polarity, either positive or negative, is output), 6 is the field of the motor generator, 7 is the electric machine 8 is an armature of a hoisting motor that drives a sheave 9 of the hoisting machine, 10 is its field, and the armatures 7 and 8 constitute a well-known Ward Leonard circuit.

11 is the main rope connecting the car 12 and the weight 13; 14
is a speedometer generator that detects the rotational speed of the armature 80 and issues a speed signal 4, 21 is a rising operation relay, 21a to 21e
is its normally open contact, 21f is also its normally closed contact, 22 is the descending operation relay, 22a to 22e are its normally open contacts, 21f
are also normally closed contacts, contacts 21 at 21 b,
22a and 22b switch the output of the voltage control device 5, which outputs only one polarity, by rising and falling, and supply it to the generator field 6, so that the generator armature 7 can output both positive and negative output voltages. I have to.

Further, contacts 21c and 21d. 22c and 22d are connected between the speedometer generator 14 and the adder 30, and are configured so that negative feedback is applied regardless of whether the speedometer is running up or down.

23 is ground, 24 is an up call relay contact that is closed when there is an up call, 25 is a down call relay contact that is energized when there is a down call, and 26a and 26b are closed while the car is running. A stop relay contact that opens with a stop command,
27 is a coil of an electromagnetic brake, and when energized, armature 8
When the spring is released and deenergized, braking torque is applied to the W element 8 by the force of the spring.

A case will be described in which an elevator controlled by the above-mentioned crawler control device lands on a floor.

In this case, for example, if the heel 12 is about to land on the floor during ascending operation and there is a call below the landing floor, the contact 24
is open and the contact 26a is closed, so the rising operation relay 21 is (-+)-(26a)-(21e)-(2
It is self-maintained by the circuit 2f)-(21)-(→.

Further, the contact 25 is closed.

In this state, when the heel 12 lands on the floor and a stop command is issued, the contacts 26a and 26b are opened, the ascending operation relay 21 is deenergized, and the electromagnetic brake coil 27 is deenergized to apply the brake.

When the ascending operation relay 21 is deenergized, the contacts 21a21b open, while the contacts 21f close, so (g)-(
25)-(21f)-(22)-(→ The descending direction relay 22 is energized by the circuit 25)-(21f)-(22)-(→), and the contact 22a is activated.

22b is closed.

As a result, the voltage control device 5 is connected to the generator's field 6 in the opposite way as it was before the up-operation relay 21 was de-energized.

Since the voltage control device 5 can only output one magnetic output,
When connected to the field 6 as described above, the current flowing through the field approaches zero, and as a result, the torque Tm of the motor decreases as shown in FIG.

On the other hand, the brake torque rises after a short period of time after a stop command is issued, as indicated by Tb.

Since the load torque T7 is constant, the combined torque becomes Tt.

In FIG. 3, the positive direction of torque means braking torque, and the negative direction means torque that causes the heel 12 to move due to the pull of the load.

In other words, when the combined torque Tt is always positive, the motor 12 does not move, but when it becomes negative, the motor 12 is accelerated in the load direction during that period.

Therefore, the motor 12, whose load torque Tt is supported by the torque Tm of the electric motor, will stop once the load is pulled at the same time as the stop command.

This poses a trip and fall hazard for passengers who are about to board or exit the vehicle at the time.

Further, even if the heel 12 does not move that much, the landing error will increase and a pleasant stop shock will occur, which will inevitably deteriorate the performance of the elevator significantly.

It is an object of the present invention to provide a control device that eliminates the above-mentioned drawbacks and allows a safe and comfortable landing even when using an inexpensive voltage control device that has only one-way polarity.

Below, Part 1. An embodiment of the present invention will be described with reference to FIGS. 4 and 5.

In FIG. 4, 28 is a mechanical brake contact that is attached to the electromagnetic brake and opens when the brake exerts sufficient braking force in conjunction with the operation of the electromagnetic brake.

The rest is the same as in FIGS. 1 and 2.

As in the conventional example, the contact 24 is open before the stop command is issued, but (g) - (28) - (21e) - (22f
)-(21)-(→ circuit, the upward operation relay 21 is self-held.

Further, when a stop command is issued, the brake coil 27 is deenergized by opening the contact 26b, but the ascending operation relay 21 is not deenergized yet.

When a stop command is issued, the brake coil is deenergized, and the brake generates sufficient braking force to support the load (time 11 in FIG. 5), the brake contact 28 opens and the relay 21 is deenergized. As a result, the motor torque Tm gradually decreases.

Since the torque Tm decreases after the brake exerts sufficient braking force Tb, the combined torque becomes Tt,
When stopped, the handle 12 does not move due to being pulled by the load.

As a result, the car 12 can safely and accurately land on the floor without any shock from stopping.

In the above example, voltage! Although the case where the I leg device 5 can only output polarity in one direction completely has been described, the voltage control device 5
Depending on the configuration, a control system such as that shown in FIG. 1 may be configured so that a small amount of output can be output even in the opposite polarity to that described above.

In this case, when the above-mentioned stop command is issued, the ascending direction relay 21 is deenergized and the descending direction relay 22 is deenergized.
Even if the motor is energized, the motor torque Tm sufficient to support the load torque can ultimately be generated by the reverse polarity output.

However, temporarily, the contacts 21a and 2 of the upward operation relay
After 1b is opened, contacts 22a and 22 of the descending operation relay
Until b is closed, the field 6 is disconnected from the voltage control device 5, or the time until the voltage control device 5 outputs an output of the opposite polarity is delayed, resulting in an instantaneous change in the motor torque Tm. Stop shock occurs.

In addition, the landing accuracy also deteriorates.

However, this can also be solved by using the (b) path as shown in FIG.

In addition, although the above description was given regarding the upward operation, the same applies to the downward operation.

Although the above explanation was made using the deenergized brake contact 28 of the ascending operation relay 21, it is not necessarily limited to the brake contact 28.
Timed relay that is deenergized at the same time as the stop command (not shown)
The same operation can be performed using .

As explained above, the present invention reverses the output of a predetermined polarity emitted from the voltage control device depending on the traveling direction of the car, and the reversal timing is set after the brake has generated sufficient braking force. can be constructed at low cost, and achieve a safe and comfortable landing.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of an elevator system, Fig. 2 is a circuit diagram of a conventional elevator control device, Fig. 3 is a torque versus time characteristic curve diagram according to Fig. 2, and Fig. 4 is an elevator control according to the present invention. FIG. 5 is a circuit diagram showing one embodiment of the apparatus, and FIG. 5 is a torque versus time characteristic curve diagram according to FIG. 4. 5...Voltage control device, 6...Motor generator field, 7...Motor generator armature, 8...
... Hoisting motor armature, 9 ... Sheave, 12.
... Car, 21 ... Rising operation relay, 2
2... Descending operation relay, 24... Up call relay contact, 25... Down call relay contact, 26a, 26b... Stop relay contact, 27...
...Brake coil, 28...Brake contact. Note that the same parts in the figures are indicated by the same reference numerals.

Claims (1)

[Scope of Claims] 1. In an elevator in which the car is controlled by an electric motor whose legs are mounted according to the Ward Leonard method, and the car is held by a brake when stopped,
A voltage control device that outputs an output of a predetermined polarity and controls the field of the generator, and an inversion device that is inserted between the voltage control device and the field of the generator and that reverses the output of the voltage control device depending on the traveling direction of either of the above. 1. An elevator control device comprising: a circuit; and a delay device that operates the reversing device after the brake has exerted sufficient braking force. 2. An elevator control device according to claim 1, which uses a voltage control device that emits an output with unidirectional polarity. 3. The elevator control device according to claim 1, which uses a voltage control device that emits an output with a unidirectional polarity, which output is also small, and whose polarity is opposite to the above-mentioned polarity.