JPH0597371A - Safety device for escalator - Google Patents

Abstract

PURPOSE:To obtain a safety device for an escalator which can suppress the self traveling speed of a step to a low value even in electric failure. CONSTITUTION:A condenser 14 for applying the condenser brake and a resistor 15 are connected in parallel with the primary coil of an inductive motor 2 through the all-time closed contact points 12c, 12d, 13c, and 13d which are put into closed state when the electric power source 6 of the electric motor 2 for driving the step 1 of an escalator is cut off. Since the self traveling speed of the step in the case when the escalator stops can be suppressed to a low speed, the turning-down trouble of a user is prevented, and the safety of users can be secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for an escalator, and more particularly to a safety control device for a brake failure.

[0002]

2. Description of the Related Art An escalator is a transportation system in which steps arranged in an endless manner are rotated by an induction motor to raise or lower passengers on the steps. When this escalator is not in use, a braking force is applied by the braking device to stop the rotation of the step, and at the same time, a heavy object on the step while the step is stopped, for example, a user who uses the stopped escalator instead of the stairs. For example, the step is held at the stopped position so as to prevent the step from self-propelling in the descending direction.

As described above, the brake device is a very important safety device among the devices constituting the escalator, and the structure thereof has a high reliability with few failures. However, if the brake system fails, the brake system may not be able to apply its braking force to the step. For this reason, there is an example in which a so-called double brake equipped with two brake devices is adopted, but it has drawbacks that the size of the escalator is large and it is expensive.

In order to prevent this, a method of electrically applying a braking force has been proposed. For example, the actual exploitation Sho 63-13048
2 discloses the schemes of FIGS. 3 and 4. In FIG. 3, step 1 is rotated by a gear 4 driven by a reduction gear 3 connected to an induction motor 2 via a chain 3a. A brake device 5 for braking the induction motor 2 is attached to the induction motor 2, and power is supplied from an AC power source 6 via a control device 7. 8 is a driving command signal, 9 is a speed generator that is connected to the induction motor 2 and detects the free-running speed of the step, 1
Reference numeral 0 is a self-propelled detector that detects the self-propelled step by the applied voltage of the speed generator 9 when the step is self-propelled due to a failure of the brake device 5, and the braking device 11 is activated by the command of the self-propelled detector 10 to be an induction motor. Generates braking force.

FIG. 4 shows an embodiment of the circuit configuration of the free-running detector 10. In the figure, R0 to R2 are resistors, and OP is an operational amplifier, which constitutes the comparator 100 by increasing the ratio of R2 / R1. Tr is a transistor, 101 is a free-running detection relay, 101a is an a contact of the free-running detection relay 101, S1 is a reset switch for cutting off the excitation of the free-running detection relay 101, and 80 is a driving command signal 8 It is a contact that opens when it is open and closes when there is no command.

When the operation command 8 is generated while the switch S1 is closed, the contact 10 is opened to open the comparator 10.
0 does not operate, and the free-running detection relay 101 remains off. When there is no operation command 8, the contact 80 is closed. At this time, if the step is self-propelled, the speed generator 9 generates a voltage. As a result, the comparator 100 generates an output voltage and turns on the transistor Tr. Therefore, the free-running detection relay 101 is excited and held by the contact 101a. That is, the free-running detection relay 101 becomes a free-running detection signal due to a failure of the brake device 5.

The braking device 11 is activated by the self-running detection signal. Although not shown in the figure, the braking device 11 separates the primary winding of the induction motor from the power source, excites the stator side with direct current, and generates heat as a generator with a resistor connected between the stator terminals to generate heat. A method of braking the induction motor by so-called dynamic braking that is consumed as is.

[0008]

However, this method requires a power supply device for applying DC excitation to the induction motor and a free-running detection device, and since it is ineffective during a power failure, it stops due to a power failure. Occasionally, it will be dangerous if the user self-propels the step.

In view of the above, the present invention provides a safety device for an escalator that can keep the self-propelled speed of a step low even during a power failure.

[0010]

The safety device for an escalator according to the first aspect of the present invention includes a capacitor on the primary winding of the induction motor through a normally closed contact that is closed when the power source of the control device is shut off. It is connected in parallel with a resistor.

A safety device for an escalator according to a second aspect of the present invention is a escalator control device driven by an inverter-controlled electric motor, wherein a normally-closed contact and a resistor are closed during power-off of the control device. Is connected to the DC input side of the inverter.

[0012]

According to the first aspect of the present invention, when the power supply to the escalator device is interrupted, the induction motor for driving the escalator is capable of braking the capacitor connected in parallel to the primary winding with the resistor. Even if it is self-propelled, the speed can be kept low and the safety of passengers can be secured.

According to the second aspect of the invention, when the power source of the inverter-controlled electric motor for driving the escalator is interrupted due to a power failure and the brake is broken, the parallel capacitor connected to the primary winding of the electric motor is connected. As a result, the induced voltage of the motor rises, and the induced voltage causes a current to flow through the resistor connected to the DC side of the inverter to regeneratively brake the motor, suppressing the self-propelled step and ensuring the safety of escalator users.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a safety device for an escalator according to this embodiment. In the figure, the same reference numerals as those in FIGS. 3 and 4 indicate the same or corresponding portions. In the figure, 12a, 1
2b is a normally open contact of a lifting contactor (not shown), 12
c and 12d are normally closed contacts of the ascending contactor, and 13a and 1d.
3b is a normally open contact of a descending contactor (not shown), 13
Reference characters c and 13d are normally closed contacts of the descending contactor. In such a configuration, the driving induction motor 2 is disconnected from the power source by the contacts 12a, 12b or 13a, 13b during the stop of the escalator or the power failure.
The capacitor 14 and the resistor 15 are connected to the induction motor 2 through the contacts 12c, 13c and 12d, 13d.

If the mechanical brake 5 is out of order and a large number of passengers are on the step 1, the step 1 starts to descend and the residual voltage of the induction motor causes the phase-advancing current through the capacitor 14 in the primary winding of the induction motor. Flows. The phase-advancing current causes the induction motor 2 to operate as an induction generator, and the primary voltage of the induction motor 2 increases. This primary voltage is determined by the capacity of the capacitor 14 and the rotation speed of the induction motor 2, and the induced voltage causes a current to flow through the resistor 15 to brake the induction motor 2. As a result, step 1 descends at a speed determined by the resistor 15 and the number of passengers, and the descending speed can be changed by the value of the resistor 15.

Next, FIG. 2 is a diagram showing the configuration of an embodiment of the second invention. In this embodiment, the drive motor of the escalator has a variable voltage and variable frequency (hereinafter referred to as an inverter).
The case of driving with a power supply device is shown. By using the inverter device, the speed of the electric motor can be arbitrarily changed. For example, the escalator can be operated at the rated speed during the morning and evening rush hours and can be operated at the low speed during the off hours during the daytime. Alternatively, it is easy to stop the escalator when there are no passengers and start the escalator when passengers arrive. At this time, the escalator is gently activated to ensure safety when passengers board.

In the figure, reference numeral 105 denotes the details of the inverter device, which is called a voltage type inverter. 1
06a and 106b are normally-open contacts of a traveling contactor (not shown) inserted between the three-phase power source 6 and the inverter 105.
Similarly, 106c to 106e are normally closed contacts. 110a
~ 110f is a transistor on the converter side, 112a ~
112f is a diode on the converter side, and 111a to 111
f is an inverter side transistor, 113a to 113f are inverter side diodes, 115 is a braking resistor, 116 is a capacitor, and the output of the inverter 105 is the induction motor 2
It is connected to the.

The transistors 110a to 110f and the diodes 112a to 112f are connected in antiparallel. Transistors 111a to 111f and diode 1
The same applies to 13a to 113f. The braking resistor 115 is connected to the inverter 1 via the normally closed contact 106c of the traveling contactor.
05 is connected to the DC circuit.

When the escalator is stopped, the inverter device 1
The base of the transistor of 05 is cut off, and it is in a cutoff state. Also, contactor contacts 106a, 1
06b is open and contactor contacts 106c-106e
Is closed, the braking resistor 115 is connected to the DC circuit of the inverter device 105, and at the same time, the phase advancing capacitor 14 is connected to the induction motor 2.

In this state, when the brake pedal 5 breaks down, if the user is on the step 1, the step 1 starts to descend and the residual voltage of the induction motor causes the capacitor 14 to advance to the primary side of the induction motor. A current flows, and this phase-advancing current further increases the induced voltage of the induction motor. This induced voltage causes the resistor 115 to cause the diode 113a ...
A current flows through 113f to brake the induction motor 2. As a result, step 1 descends at a speed determined by the resistor 115 and the number of passengers, but this speed is suppressed to a low speed by the value of the resistor 115.

Even if the induction motor 2 is a linear motor, the same effect is obtained. Furthermore, when using inverter control,
There is also a method of using a synchronous motor instead of the induction motor 2. In the case of the motive motor, since the field magnetic flux is established, the contactor contacts 106d and 106e and the capacitor 14 of FIG. 2 are unnecessary, and the braking force acts more quickly than in the case of the induction motor, which is safer. .. In FIG. 2, the braking resistor 15 may be directly connected to the primary side of the induction motor as in FIG. 1, but a three-phase circuit requires three resistors, which complicates the circuit. In FIG. 2, the configuration is extremely simple by only inserting one resistor 115 in the DC circuit.

[0022]

As described above, according to the first aspect of the invention, since the induction motor for driving the escalator is configured to perform the capacitor braking, even if the step is self-propelled due to a brake failure at the time of power failure of the escalator device. The self-propelled speed can be suppressed to a low speed by the capacitor braking, and the accident of the customer can be prevented and the safety of the customer can be secured.

Further, according to the second aspect of the present invention, when the step is self-running due to a brake failure when the escalator driving electric motor is stopped by the inverter control, the induction of the electric motor is induced by the capacitor connected in parallel to the primary winding of the electric motor. The voltage rises, and the induced voltage causes a current to flow in the resistor connected to the DC side of the inverter, which causes regenerative braking to slow the free-running speed of the step. Therefore, in addition to the effect of the first invention, a simpler circuit is provided. With the configuration, it is possible to secure the safety of the user on the step when the brake fails.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a safety device for an escalator according to an embodiment of the first invention.

FIG. 2 is a configuration diagram of a safety device for an escalator according to an embodiment of the second invention.

FIG. 3 is a configuration diagram of a conventional safety device for an escalator.

FIG. 4 is an internal configuration diagram of the free-running detector 10 shown in FIG.

[Explanation of symbols]

 1 step 2 induction motor 5 mechanical brake 14 parallel capacitor 15 parallel resistor 105 inverter device 106c normally closed contact 12c, 12d, 13c, 13d normally closed contact

Claims (2)

[Claims] 1. A control device for an escalator driven by an induction motor, wherein a capacitor and a resistor are connected to a primary winding of the induction motor via a normally-closed contact which is closed when the power supply of the control device is cut off. Escalator safety device characterized by being connected in parallel. 2. A controller for an escalator driven by an inverter-controlled electric motor, wherein a series body composed of a normally-closed contact and a resistor, which is in a closed state during the power-off of the controller, is connected to a DC input side of the inverter. Escalator safety device characterized by being connected.