KR900006399B1 - Savety devices of elevator - Google Patents

Abstract

The safety device of an elevator has a speed instruction provision circuit (10) for instructing the speed of an elevator car, a speedometer generator for detecting the car speed, a safety circuit (16) operating when the difference between the output of the speed instruction provision circuit and the output of the speedometer generator is larger than the predetermined value, and a polarity observation circuit (26) for detecting the polarity disorder which the second polarity appears at ascending operation or the first polarity appears at descending operation.

Description

Elevator safety device.

1 is an overall circuit block diagram of a safety device of an elevator according to an embodiment of the present invention.

2 is an operation sequence circuit diagram of the elevator safety device described in FIG.

3 is a circuit diagram of a polarity monitoring circuit.

4 is another circuit diagram of the polarity monitoring circuit.

5 is an overall circuit block diagram of a conventional apparatus.

6 is an operation sequence circuit diagram of a conventional apparatus.

* Explanation of symbols for main parts of the drawings

1: elevator car 2: counterweight

8: thyristor converter 9: call control circuit

10: speed command generation circuit 16: safety circuit

26: polarity monitoring circuit

In the drawings, the same reference numerals indicate the same or corresponding parts.

This invention relates to the improvement of the safety window of an elevator.

5 and 6 are, for example, the overall circuit diagram and the seguence circuit diagram of a conventional elevator safety device shown in Japanese Patent Laid-Open No. 53-18157, where l is an elevator car (hereinafter abbreviated as car). , 2 is counterweight, 3 is pulley of hoist, 4 is deflection pulley, 5 is main rope, 6 is armature of DC motor driving pulley 3, 6a is same field, 7 is 3-phase AC power source, 8 is A thyristor controlled rectifier, 9 is a firing control circuit, 10 is a speed command generation circuit for generating a speed command 10a, 11 is a main circuit contactor, 1la is a regular of the main circuit contactor {11). Open contact, 11b is a normally closed contact, 12 is a braking resistor, 13 is a first speedometer generator driven by the armature 6, 14 is a second speedometer generator, 15 is an adder, 16 is a safety circuit described below, 16a is the normally closed contact of the safety circuit 16, 17 is the top gun, 18 is the bottom floor, 19 is the car (1). The cam attached to the cam 20 is an end switch which is coupled to the cam 19 when the car 1 installed on the hoist reaches the top floor 17, 20a is its normally closed contact, and 21 is similarly a car (1). ) Reaches the bottom layer 18, the end switch is coupled to the can 19, 21a is the normal closing contact, 22 is the forced deceleration relay (23a) and 23b is the normal opening of the driving relay (not shown) The contact point 24 denotes a normally closed contact of an ascending operation example (not shown), the reference numeral 25 denotes a normally closed contact of a descending operation relay (not shown), and the positive and negative poles of the power supply.

Next, the operation of the conventional elevator safety device will be described.

When the start command of the car 1 is issued, the driving relay contacts 23a and 23b are closed.

As a result, the forced deceleration relay 22 and the main circuit contactor 11 are operated so that the contact 1la is closed and the contact 1lb is opened. In addition, the speed command generation circuit 10 operates to generate the speed command 10a, and the call command is supplied to the thyristor converter 8 by the call control circuit 9. Accordingly, the three-phase alternating current 7 is converted into direct current power of a variable voltage and supplied to the armature 6.

The electricity of the armature 6 is detected by the speedometer generator 13 and returned to the firing control circuit 9, whereby the running speed of the car 1 is controlled to a high degree.

The speedometer generator 14, the adder l5 and the safety circuit 16 are installed to ensure the safety of the elevator.

In other words, in the adder 15, the speed is subtracted from the speed command 10a, and the output of the generator 14 is subtracted to obtain the deviation 15a.

As long as the elevator is operating normally, the deviation 15a is almost zero, but when the failure occurs in the apparatus and the deviation 15a becomes more than a predetermined value, the safety circuit 16 operates.

As a result, the contact 16a is opened to cut off the main circuit contactor 11 and the contact 1la is opened to disconnect the armature 6 from the thyristor converter 8.

At the same time, the contact 1lb is closed to connect the braking resistor 12 to the armature 6 to emergency stop the car 1.

However, the safety circuit 16 in the above-mentioned conventional elevator safety device is effective against the following failure.

(A) When the speedometer generator 13 fails and the output voltage decreases, the speed of the car 1 increases and the deviation 15a increases, so that the safety circuit 16 operates.

(B) In the case of failure of the firing control circuit 9, the deviation 15a also increases, and the safety circuit 16 operates.

(C) In the case where terminals such as the armature 6, thyristor converter 8, or contact 1la are loosened and power cannot be supplied to the armature 6, the deviation 15a increases in a similar manner and the safety circuit 16 It works.

In this way, the safety circuit 16 operates effectively against various failures, but the failure cannot be detected in the following cases.

In other words, when the speed command generation circuit 10 is broken, the safety circuit 16 is ineffective because the device is configured so that the car speed follows the speed command 100a.

In particular, when the polarity of the speed command 10a is reversed due to a failure of the speed command generation circuit 10, the car 1 travels in the opposite direction of the command direction and collides with the shock absorber at high speed, which is extremely dangerous.

In general, the elevator is provided with a forced reduction device in order to prevent the car 1 from passing through the uppermost floor 17 or the lowermost floor 18 at high speed.

For example, when the car 1 is driven up to reach the uppermost floor, the can 19 is engaged with the end switch 20 so that the contact 20a is opened and the forced deceleration relay 22 is blocked. Accordingly, for example, the deceleration stop operation is immediately performed by the blocking of the relay 22 even when the car 1 is driving at high speed.

However, if the polarity of the speed command 10a is inverted due to a failure of the speed command generation circuit 100, the forced deceleration operation described above is not performed.

For example, the car 1 is said to be descending because the direction of the command is the rising side, but the polarity of the speed command 10a is reversed.

Since the rising operation relay contact 24 is open and the down operation relay contact 25 is closed, and the driving relay contact 23a is closed, the forced deceleration relay 22 is (+)-(20a)-(25). It is held by the circuit of)-(23a)-(22)-(-).

On the other hand, since the car 1 is lowered, the end point switch 20 cannot operate, and thus the force reduction relay 22 does not block the force. Therefore, the car 1 may pass through the lowermost floor and collide with the shock absorber at a high speed, which may injure passengers.

In addition, the circuit of the forced deceleration relay 22 needs to be the circuit of FIG. 6 in order to be able to descend to rectification at the uppermost floor or to ascend regularly at the lowermost floor. Therefore, the polarity of the speed command 10a is required. Leading to this reversal failure will lead to the above-mentioned dangerous situation.

Since the safety threshold of the conventional elevator is configured as described above, there is a problem in that it is incapable of failure of the speed command generation circuit, and particularly, when the polarity of the speed command reverses and breaks, it causes serious harm to the passenger.

This invention solves the above-mentioned problems, and an object of the present invention is to obtain a safety device for an elevator that can immediately stop a car in the event that the polarity of the speed command reverses.

The safety device of the elevator according to the present invention is configured to monitor the deviation signal between the speed command and the speedometer generator output in the safety circuit and to monitor the polarity of the speed command in the polarity monitoring circuit.

The safety device of the elevator according to the present invention detects the failure promptly by the polarity monitoring circuit and promptly even if the polarity of the speed command is reversed due to the failure, especially when the speed command is reversed due to the failure. Emergency stop the car.

Hereinafter, an embodiment of the present invention will be described. 26 in FIG. 1 and FIG. 2, the polarity monitoring circuit 111a which monitors the polarity of the speed command 10a is a normally closed contact of the abnormality detection relay 111 mentioned later. Others are constructed as shown in FIGS. 5 and 6. 3 shows a circuit diagram of the polarity monitoring circuit 26, in which 24a is a normal open contact of the rising operation relay, 25a is a normal opening contact of the falling operation relay, 101 and 105 are operational amplifiers, and 102-104. And 107-109 are resistors, 106 is a reference voltage, 110 is a transistor, 111 is a fault detection relay, 112 and 113 are diodes, Vcc is a positive power supply, 101-104 is an inverting amplifier, and 105-108 is a comparator.

It is now assumed that the polarity of the speed command 10a is the first polarity in the rising operation and the second polarity in the falling operation. In the rising operation, the rising operation relay contact 24a is closed, so the speed command 10a is directly connected to the resistor 107. On the other hand, during the descent operation, the descent operation relay contact 25a is closed so that the speed command 10a is an inverting amplifier composed of (101)-(104) the same absolute value and the polarizer is inverted and connected to the resistor 107.

Therefore, since the first polarity speed command is always applied to the resistor 1107, the output of the operational amplifier 105 is negative, so that the transistor 110 is turned off and the abnormal detection relay 111 is turned off. The force is removed and the contact point 111a is closed to allow the elevator to travel.

However, when the speed command generation circuit 10 has a failure and is still in the ascending operation, the polarity of the speed command 10a is the second polarity or the speed command 10a is the first polarity despite the falling operation. A negative voltage is applied to the silver resistor 107. If the voltage exceeds a predetermined value determined by the reference voltage 106, the output of the operational amplifier 105 is positively inverted, the transistor 110 operates to operate the abnormality detection relay 111 to operate the contact 111a. Open.

Accordingly, the main circuit contactor l1 is cut off and the contact 1la is opened to disengage the armature 6 from the thyristor converter 8, and at the same time the contact 1lb closes and the braking resistor 12 is moved to the armature 6. The car 1 is emergency stopped.

As a result, even when a failure in which the polarity of the speed command 10a is reversed occurs, the car 1 can be safely stopped, thereby preventing the risk of striking the buffer at a high speed.

When the car 1 travels in the reverse direction due to the failure of the call control circuit 9, the safety circuit 16 operates and the accident can be prevented because the deviation 15a is significant.

In this way, when the deviation 15a becomes more than a predetermined value, the safety of the elevator can be greatly improved by using the safety circuit 16 and the polarity monitoring circuit 26 that operate.

In addition, although the speed command 10a was used for the input of the polarity monitoring circuit 26, the structure of using the output of the speedometer generator 14 may be used instead.

However, in the following point, it is advantageous to use the speed command 10a for the polarity monitoring circuit 26. For example, consider a case where the car 1 is started in the upward direction with the rated load loaded.

As is well known, since the counterweight 2 of 50% of the rated load of the elevator is adopted, the car 1 is heavy in this case.

For this reason, during start-up, the car 1 tends to be pulled downwards and then rises. At this time, if the polarity is monitored by the output of the speedometer generator 14, a malfunction is caused by inadvertent operation. This occurs. In order to prevent this, it is necessary to deteriorate the detection sensitivity or to invalidate the detection at the start-up or on the ground, thereby lowering the reliability of the safety circuit 16.

On the other hand, in this invention, since the polarity monitoring of the speed command 10a is performed, the reliability of the safety circuit 16 can be improved if the above-mentioned defect does not occur.

4 shows another embodiment of this invention. In the elevators in the rising and falling operation, the polarity of the speed command is the first polarity, for example, and the polarity of the speedometer generators 13 and 14 is switched according to the driving direction to (101)-(104). A circular inverting amplifier is required and the circuit configuration is simplified.

In the embodiment of the present invention, the polarity monitoring circuit 26 is provided together with the safety circuit 16, but the polarity monitoring circuit 26 may be provided.

As described above, in the present invention, when the deviation signal between the speed command and the speedometer generator exceeds a predetermined value, a circuit for monitoring the polarity of the speed command is provided in addition to the safety circuit that operates, so that even if the polarity of the speed command becomes abnormal,逆 走) can be prevented in advance and the safety operation of the elevator can be secured.

Claims (1)

A speed command generation circuit for commanding the speed of the car, a speedometer generator for detecting the speed of the car, and a safety circuit that operates when the deviation between the output of the speed command generator and the output of the speedometer generator exceeds a predetermined value. And a polarity monitoring circuit which judges that the polarity of the speed command generated by the speed command generation circuit is greater than or equal to the polarity when the car becomes the second polarity during the car up operation or the first polarity during the car down operation. Elevator safety device.

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