SU1471173A1 - Device for emergency stop of drive with self-check of communication line - Google Patents

Abstract

The invention relates to automation, in particular, to devices for emergency shutdown of large-scale flow-transport mechanisms with possible displacements of the working bodies from the direction of cargo transportation. The purpose of the invention is to increase the reliability of the device, expanding its functionality. The device contains a rectifier 1, a signal converter 2, a two-wire communication line 3, an indication unit 4, switches 5, a resistor 6, sensors 7, a switch 10, a setting device 11 device operation modes, a decoder 12, an actuator control unit 13, comparators 14- sixteen. Introduction of rectifier 1, setter 11 of operation modes and decoder 12 allows to expand the functionality of the device by providing the ability to determine the type and nature of the failure, and in case of short-term failures, automatically restore the device’s performance and, accordingly, increase the reliability of its operation. 2 Il.

Description

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The invention relates to automation, in particular, to emergency shutdown devices for large-scale flow-transport mechanisms with possible displacements of the working bodies from the direction of cargo transportation.

The aim of the invention is to increase the reliability {care of the device and the expansion of its functionality.

Fig „1 shows the functional diagram of the device; FIG. 2 is a schematic diagram of the device;

The device contains rectifier 1 converter 2 signals, two-wire communication line 3, indication unit 4, switches 5, end resistor 6, sensors 7 consisting of series-connected open contacts 8 and resistors 9s key 1 O, setting Chik 11 device operation modes, decoder 12, executive drive control unit 13 and comparators 14 - 1 6 "

In Fig. 2, reference points 17 to 19 of the thresholds of the comparators 14 to 16, resistors 20 to 22 of converter 2, which comprise the three arms of the measuring bridge, the fourth ply of which represents the sum of the resistances of the cable 23 of the communication line and end resistor 6, are designated.

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The key 10 consists of a zener 24 that sets the threshold for triggering a thyristor composed of elements of transistors 25 and 26, resistors 27 and 28, in series with which a limiting resistor 29 and a transistor optocoupler 30 are connected, the initial operating mode of which is set by resistors 31 and 32. Parallel to the thyristor of the key 10 are connected to the setpoint adjuster, 1 operating modes, the output part of the optocoupler 33, whose basic resistance is the resistor 34, The input part of the optocoupler 33 is connected through the limiting resistor 35 to the collector of transistor 36, bases and through a resistor 37 it is connected to the output of a generator of rectangular pulses, assembled on the elements AND-HE 38-40, a capacitor 41, resistors 42-44. A toggle switch 45 is connected to one of the inputs of the NAND 39 (a resistor 4 is connected to the same input, providing the potential of a logic zero at the input when the switch is turned off

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35 40 45 jg, §5 of the toggle switch 45). Through the limiting resistors 46 and 47, comparators 14–16, consisting of reference voltage dividers on pairs of resistors 48 and 49, 50 and 51, 52 and 53, feedback resistors 54–56 connected to the output terminal, are connected to the output diagonal of the measuring bridge. op-amps 57-59 and to the midpoints of the indicated reference voltage dividers, resistors 60-62 are connected to the outputs of the operational amplifiers, limiting the base current of transistors 63-65, and resistors 66-68 serve to limit the collector current of transistors and create a potential of logical units Nica in the closed state of data transistor at the corresponding inputs of the decoder 12 is connected to the outputs of the comparators 4-16,

The single output of the two-stage trigger 69 is connected to the second output of dehffrarator 12, the information input of which is connected to the supply voltage, the installation input in the single state — wire S synchronization input — to the output of the decoder, the zero setting input through the capacitor 70 is connected to common wire, and through parallel connected trimmer resistor 71 and diode 72 to the output of trigger 69, which is connected to the input of element 2 OR-NE 73, the second input of which is connected to the first output of the decoder 12, and the output through The inverter 74 and the limiting resistor 75 are connected to the base of the transistor 76, which controls the electromagnetic relay 77; The second, third, fourth, and fifth outputs of the decoder 12 are connected via the limiting resistors 78-81 respectively to the transistor switches 82 - 85, controlling through the limiting resistors 86-89 by information LEDs 90-93. The entire executive part of the device operates from a bipolar direct current source 94.

The device works in the following way,

In the initial state, in the presence of supply voltage from rectifier 1, integrity, wires of communication line 3, closed contact switches 5, open contactdv 8, the measuring bridge of converter 2 is broken: {1 sirovannn4, from its output the signal goes to the inputs of Comparators 1A - 16, since the signal does not exceed the specified levels of the reference signals of the comparators, then at the output of the comparators the potentials of a logical zero are formed, which arrive at the inputs of the decoder 12 and allow control of the actuator, since The first output of the decoder 12 turns on the relay 77. The measuring bridge of the converter 2 turns out to be unbalanced because the product of the resistance values of the resistor 21 and the sum of the resistances of the loop of the communication line 3 and the end resistor 6 is greater than the product of the resistance values of the resistor 20 - suppression of resistor 22, i.e. the potential of the point between the resistors 21 and 22 is less than the potential between the resistors 20 and 46. Thus, the output signal of the measuring bridge has a negative potential.

When naff from the rectifier 1 disappears, the output signal of the measuring bridge of the transducer 2 becomes equal to zero and exceeds the level of the reference voltage of the gauge 17 of comparator G4a, which leads to the appearance of a logical unit at its output. The occurrence at the third output of the decoder 12 of the potential of the logical unit leads to the activation of the LED 90, which signals the power supply voltage of the measuring bridge of the converter 2 and the communication line 3, and the loss of potential at the first output of the decoder leads to the disconnection of the relay 77, t . drive. The occurrence of voltage from the high voltage 1 causes the device to reset.

When one of the operating elements of the transport mechanism is displaced in the direction beyond the allowable limits, contact 8 is closed, which leads to connection of a resistor 9 to the communication line 3, which, connected in parallel with the end resistor 6, reduces the resistance of the measuring converter arm 2 rebalancing and the appearance of a small amplitude positive potential at its output. This signal in its amplitude exceeds the value of the reference voltages of the setting devices 17 and 18

comparators 14 and 15, which causes the appearance of the potential of a logical unit at their outputs. These signals transfer the decoder 12 to the position at which the potential appears at the second output, this potential turns on the LED 91, which indicates the displacement of the working element, and starts a one-shot, providing. time delay for switching off the relay 77 After the end of the one-cycle operating time, if the working element has not returned to its original position, the relay 77 will be turned off.

Wire freezing is an emergency mode, which requires immediate disengagement of the drive mechanism. In this case, the measuring bridge of the converter 2 with the end resistor 6 is short-circuited, which leads to the rebalancing of the bridge of the converter 2 and the appearance of a positive potential at its output, the amplitude of which is higher than the reference voltages of all the comparators, i.e. all comparators at the outputs appear logical units, which causes the relay 77 to turn off and the LED 92 to turn on, indicating a short circuit in the line. When link 3 is restored, the device returns to its original state.

Opening any of the contacts of the switches 5 or breaking the communication line 3 causes the full potential of the rectifier 1 to be applied to the zener diode 24, which is included in the relaunch. The direct current flowing through the circuit is the positive pole of the rectifier 1, resistor 20, zener diode 24, resistor 28, negative output of rectifier 1, the voltage drop across the resistor 28, which leads to the thyristor opening of the transistor optocoupler 30, from which output the potential is logical units are fed to the input of the decoder 12. Turning on the thyristor leads to a short circuit simulation in the communication line 3, i.e. The appearance at the output of the transducer 2 of a large amplitude positive potential and a change in the state of all the comparators. LED 93 is turned on, indicating a break in the communication line, since logical units appeared at all inputs of the decoder 12.

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The potential of the logical course of the optocoupler 30-rectangular unit designed to be reset using a transistor output part of which the anode with the cathode of the pulse thyristor is activated and its rasabolor 45 is turned on, when it is decided to generate a pulse to reset the thyristor.

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and as soon as the line is restored, the device returns to its original position. If the toggle contacts 45 are open, which prohibits the operation of the generator, the appearance of even a brief interruption in the communication line will turn on the thyristor and turn off the drive. The device can now be reset to its original state only with external human intervention after the cause of the shutdown has been removed by turning off the switch or turning on the toggle switch 45.

Claims (1)

Invention Formula Device for emergency stop of the drive with self-monitoring of the communication line, containing a signal converter, the first input of which is connected to the communication line formed by series-connected switches, the connection points of which are connected to the first terminals of the corresponding parallel-connected sensors, the second outputs of which connected to the second input of the signal converter, the output of which is connected to the first comparator, the second and third comparators and the display unit, characterized in that, for the purpose of expansion, the function capabilities, increase the reliability of the device, a switch, a key, an end resistor, a device operating mode sensor, a decoder and an actuator control unit, whose inputs are connected to the first and second outputs of the decoder connected to the output of the key, are entered into it. and the second, third and fourth inputs to the outputs of the first, second and third comparators, respectively, whose inputs are connected to the output of the signal converter, the first and third inputs of which are connected respectively the negative and positive leads of the rectifier, the output of the sensor of the device operation modes is connected to the control input of the key; the power inputs of which are connected to the first and second inputs of the signal converter; connected switches - to the first input of the signal converter, the second, third, quarter and five outputs of the decoder are connected to the inputs of the display unit. but .J HI .5 bnllj - j u v I L ± --Tic 11 - j L vj I   - H czizLJ  f W- i