KR200178830Y1 - F/r control circuit of dc motor - Google Patents

Abstract

The present invention relates to a forward / reverse control circuit of a DC motor that detects a DC motor abnormally and prevents equipment accidents and safety accidents in advance, and uses a PLC system, a communication interface, and a drive system. Abnormal operation of DC motor to detect errors occurring in any one of PLC system, communication interface card and drive system in DC motor control circuit driving DC motor in forward or reverse direction to operate crane in cab The DC motor is configured to further include a detection means, wherein the PLC system is controlled according to the output signal of the abnormal operation detection means of the DC motor, and the DC motor is configured to be driven according to the output signal of the PLC system. Provide reverse control circuitry.

Description

F / R control circuit of DC motor

The present invention relates to a forward / reverse control circuit of a direct current motor, and more particularly, to a forward / reverse control circuit of a direct current motor capable of quickly detecting the abnormal operation of a direct current motor to prevent facility accidents and safety accidents. will be.

In general, cranes installed in raw material docks, product docks, and domestic or foreign container docks industrial sites of steel mills are used by direct / reverse operation of a direct current motor in a cab.

1 is a conventional DC motor forward / reverse control circuit diagram.

In the cab 100, the DC motor 150 is driven in the forward direction 102 or the reverse direction 101 to operate the crane. At this time, when a malfunction occurs in any one of the PLC system 120 and the drive system 140 or the communication interface card 130, the phenomenon is that the driving in the opposite direction rather than the driving direction to operate.

That is, when the DC motor 150 is arbitrarily driven without a driving signal in the standby direction or when driving in the opposite direction than the driving direction to be operated, the risk of facility accident and safety accident is followed. In addition, malfunction of the PLC system 120, the communication interface card 130, and the drive system 140 when the cab 100 is in a standby state before performing the operation of the normal 102 and the station 101 in the cab 100. Due to the generation of the DC motor 150 driven by the taco generator 160 is arbitrarily driven, there is a problem that a facility accident and a safety accident occurs.

Malfunctions of the PLC system 120, the communication interface card 130, and the drive system 140 are caused by external noise, deterioration of the element of the card itself, and abnormality of the card element due to the environment (dust, temperature, vibration), and the like. And due to equipment vibration or connection and poor contact.

When such a malfunction occurs, the following problems occur.

First, the normal data value is inverted to an abnormal data value so that operation is reversed (forward operation is reverse operation and reverse operation is forward operation). In the PLC system 120 and the drive system 140, the abnormal detection pulp ( Fault) The contents cannot be checked.

Second, the crane is operated arbitrarily during abnormal operation other than normal operation.

Third, the DC motor is driven without a driving signal, the crane is not stopped, and the contents of the abnormality detection pulp cannot be confirmed.

Fourth, there is no precaution and there is always a risk of a relapse.

Fifth, there is no safety device for detecting and stopping to solve the above problems.

Therefore, the present invention provides a forward / reverse control circuit of a direct current motor that can detect an abnormal operation of a direct current motor by using the abnormal operation detection means of the direct current motor to prevent facility accidents and safety accidents in advance. The purpose is.

The direct / reverse control circuit of the DC motor according to the present invention for achieving the above object is a DC motor for driving the DC motor in the forward or reverse direction to operate the crane in the cab using a PLC system, communication interface and drive system The control circuit further comprises an abnormal operation detecting means of a DC motor for detecting an error occurring at any one of the PLC system, the communication interface card, and the drive system, and the abnormal operation detecting means of the DC motor. The PLC system is controlled according to the output signal of the DC motor, characterized in that configured to be driven in accordance with the output signal of the PLC system.

In addition, the abnormal operation detection means of the DC motor includes a forward / reverse voltage drive circuit for inputting a voltage generated by the taco generator, and a forward / reverse control for controlling the voltage output from the forward / reverse voltage drive circuit to a constant voltage. A circuit, a forward / reverse output limit circuit for controlling an output stage according to the output voltage of the forward / reverse control circuit, and a forward / reverse phototransistor and a forward / reverse driven according to the output voltage of the forward / reverse output limit circuit. It is characterized by including a light emitting diode and a forward / reverse relay.

1 is a block diagram of a conventional DC motor forward / reverse control circuit.

2 is a block diagram of a direct-current motor reverse / reverse control circuit to which the present invention is applied.

Figure 3 is a detailed circuit diagram of the abnormal operation detection means of the DC motor according to the present invention.

4 is a forward control circuit diagram of FIG. 3.

5 is a reverse direction control circuit diagram of FIG.

6 is a sequence circuit diagram for explaining the operation of the present invention.

<Description of Symbols for Major Parts of Drawings>

1, 2: Input stage 3, 4: Photo-Tr

R1 to R22: Resistor

D1 to D8: Diode

Q1 to Q12: transistor (Tr) C1 to C4: condenser

K1, K2: Relay 100: Cab

102: forward operation 101: reverse operation

120: PLC system 130: communication interface card

140: drive system 150: DC motor (DC Motor)

160: Tacho generator

170: abnormal operation detection means of the DC motor

a, a-1: voltage drive circuit b, b-1: control circuit

c, c-1: output limit circuit

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a DC motor forward / reverse control circuit according to the present invention, and includes an abnormality detecting unit 170 of the DC motor in the existing DC motor forward / reverse control circuit.

3 is a detailed circuit diagram of the abnormal operation detection means of the DC motor according to the present invention, FIG. 4 is an abnormal detection circuit diagram of the forward DC motor of FIG. 3, and FIG. 5 is an abnormal detection circuit diagram of the reverse DC motor of FIG. 3.

Forward / reverse voltage drive circuits (a, a-1) to which the output voltage of the taco generator 160 is supplied to the input terminals 1 and 2, and voltages supplied from the forward / reverse voltage drive circuits (a, a-1). Forward / reverse output limit circuits for controlling output relays k1 and k2 according to the outputs of the forward / reverse control circuits (b, b-1) and forward / reverse control circuits (b, b-1). (c, c-1).

The present invention detects a change in the output voltage, compares it with a reference voltage, and uses the difference to vary a bias voltage of the amplification control transistor so that the output voltage is always kept constant.

It is connected to the drive system card so that the output voltage of the taco generator 160 is supplied to the input terminals 1 and 2. The diodes D1 and D5 are diodes for distinguishing between normal and reverse in forward / reverse driving.

During the forward operation, the output voltage of the taco generator 160 is supplied to the diode D1 to operate the forward voltage drive circuit a, the control circuit b, and the output limit circuit c. In reverse operation, the output voltage of the taco generator 160 is supplied to the diode D5 to operate the reverse voltage drive circuit a-1, the control circuit b-1 and the output limit circuit c-1. do.

The forward / reverse voltage drive circuits a and a-1 include forward transistor Q2 and reverse transistor Q8 as control power transistors, forward transistor Q1 and reverse transistor Q7 as voltage amplification transistors, It consists of forward capacitors C2 and C3 which are smoothing capacitors, and reverse capacitors C1 and C4.

The forward / reverse control circuits b and b-1 are composed of forward transistors Q3 and Q4, which are reference voltage amplifying transistors, and reverse transistors Q9 and Q10.

The forward / reverse output limit circuits c and c-1 include the zener diodes D3 and transistors Q5 in the forward direction and the zener diodes D7 and transistors Q11 and the forward / reverse phototransistors 3 and 4 in the reverse direction. And forward / reverse relays K1 and K2.

The forward / reverse zener diodes D3 and D7 of the forward / reverse output limit circuits c and c-1 serve to cut off the circuit when the abnormal voltage is output. In addition, the forward / reverse phototransistors 3 and 4 are driven according to the voltages output from the forward / reverse output limit circuits c and c-1 so that the forward / reverse light emitting diodes D4 can be known. And D8) is turned on, and the forward / reverse driving direction signal is supplied to the PLC system 120 through the forward / reverse relays K1 and K2. First, the operation during the forward operation will be described.

As shown in FIG. 2, the motor 150 operates when the data interface is normally performed in the PLC system 120 or the communication interface card 130 and the drive system 140. While the voltage generated by the taco generator 160 for speed driving is connected to the terminal block of the control card in the drive system 140, the input terminals 1 and 2 of FIG. 3 are connected to the diode D1 in the forward direction. The voltage drive circuit a, the control circuit b and the output limit circuit c are driven. At this time, the phototransistor 3 is operated, the light emitting diode D4 is turned on, and the relay K1 is operated. At this time, the DC motor 150 is normally driven by the program of the PLC system 120.

In the reverse operation, the reverse operation is performed in the same operation as in the forward operation.

However, when it operates normally in the forward operation and operates incorrectly, voltage is applied to the diode D5, which is the reverse circuit, and the phototransistor 4 of the output terminal is driven so that the light emitting diode D8 is turned on and the relay K2 is turned on. It works. At this time, the DC motor 150 is stopped by the program of the PLC system 120.

If the motor is driven in the forward direction due to a malfunction during the reverse operation, the relay K1 is operated in the reverse direction. At this time, the DC motor 150 is stopped by the program of the PLC system 120.

If the DC motor 150 is driven in the forward or reverse direction due to a malfunction in the PLC system 120, the communication interface card 130, and the drive system 140 without a driving signal, the taco generator 160 output voltage is reversed. The relays K1 or K2 of the output terminals are operated by being input to the input terminals 1 and 2 to stop the DC motor 150 by the program of the PLC system 120.

6 is a flowchart illustrating a sequence operation of the PLC system according to the present invention.

In the forward driving of the DC motor 150, the driving is normally performed by the sequence 201. In addition, during the reverse operation of the DC motor 150, the sequence 202 is normally operated.

However, if the normal operation during the forward operation is operated in a malfunction, the DC motor 150 is stopped by the sequence 203.

In addition, when the motor operates normally during the reverse operation and operates in a malfunction, the DC motor 150 is stopped by the sequence 204.

When the DC motor 150 is driven without the forward reverse driving signal, the DC motor 150 is stopped by the sequences 205 and 206.

As described above, according to the present invention, when the DC motor is operated in the opposite direction instead of the driving direction due to a malfunction of the PLC system, the communication interface card and the drive system, or the DC motor is driven without a driving signal, In this case, by quickly detecting this in the abnormal operation detection means of the DC motor to stop the crane, it is possible to prevent equipment accidents and safety accidents in advance, there is an excellent effect that can prevent work efficiency and failure propagation phenomenon.

The foregoing is merely illustrative of the preferred embodiments of the present invention, those skilled in the art to which the present invention pertains can make modifications and changes to the present invention without departing from the spirit and spirit of the invention as described in the appended claims. .

Claims (2)

In a DC motor control circuit that drives a DC motor in a forward or reverse direction to drive a crane in a cab using a PLC system, a communication interface and a drive system, And an abnormal operation detecting means of the DC motor for detecting an error occurring at any one of the PLC system, the communication interface card, and the drive system, and according to the output signal of the abnormal operation detecting means of the DC motor. The PLC system is controlled, the forward / reverse control circuit of the DC motor, characterized in that configured to drive the DC motor in accordance with the output signal of the PLC system. The method of claim 1, The abnormal operation detection means of the DC motor includes a forward / reverse voltage drive circuit for amplifying the output voltage of the taco generator; A forward / reverse control circuit for controlling the output voltage of the forward / reverse voltage drive circuit to a constant voltage; A forward / reverse output limit circuit for controlling an output terminal according to the output voltage of the forward / reverse control circuit, A forward / reverse phototransistor driven by an output voltage of the forward / reverse output limit circuit, A forward / reverse control circuit of a direct-current motor comprising a forward / reverse light emitting diode and a forward / reverse relay operated according to the driving of the forward / reverse phototransistor.