SU962043A1 - Electric locomotive braking system - Google Patents

Description

(54) DEVICE FOR ELECTRIC BRAKING DRAWING

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The invention relates to the field of automatic train driving in railway transport and is intended to automate the control of brake means of an electric locomotive, mainly mine.

A device for braking an electric locomotive, preferably a scraper, containing an electrodynamic braking unit connected to a power-on unit and a mechanical brake to its control unit 1 is known.

The drawbacks of such a device are due to the fact that the monitoring of braking efficiency is due to the braking current of the engine. At the same time, the actual deceleration of movement is determined by the weight of the train and the profile of the track, which, under the conditions of mining, changes by a factor of 3-4. Different deceleration rates with the same threshold braking current for the activation of a mechanical brake in some cases lead to an increase in the longitudinal dynamic forces, and in others to an increase in the stopping distance. The device does not provide the possibility of activating the mechanical brake in case of failure of the electrodynamic braking control devices. In addition, the introduction of a rectifying bridge, windings, brake coil and undercurrent sensor into the motor circuit increases the resistance of the motor and reduces the reliability of the drive.

The purpose of the invention is to increase the reliability of the device.

To achieve this goal, the device is equipped with a comparator, a differentiating unit, a coincidence unit and a train speed sensor, the output of which is connected to the input of a differentiating unit connected by an output to an inverting comparator input connected to the output of one of the input blocks of the coincidence unit the train, and the third to the output of the electrodynamic braking control unit; the output of the coincidence unit is connected to the mechanical brake control unit.

The drawing shows a block diagram of the proposed device.

The device contains a train speed sensor 1, the output of which is connected via a differentiator 2, made on a capacitor 3, resistor 4 to a diode 5, to a comparator 6 made on a differential operational amplifier, the output of which is connected to one of the inputs of the coincidence unit 7, the other inputs of which are connected with the output of the electrodynamic braking unit 8, and with the output of the train speed sensor 1. The device also comprises a mechanical brake control unit 9 and an electrodynamic braking unit 10. At the same time, the brake control 9 of the mechanical brake is made on the electro-pneumatic valve of the pneumatic brake 11 and the time-delay element 12.

The device works as follows.

During steady-state movement of the train, the capacitor 3 is charged until the voltage of the speed sensor 1. When a braking command is given, the electrodynamic braking actuation unit 8 outputs a voltage to the electrodynamic braking unit 10 and to one of the inputs of the coincidence unit 7. When the train is braked, capacitor 3 is discharged to speed sensor 1, and a voltage is generated across resistor 4 that is proportional to the train slowing down. If this voltage is greater than the reference U, then the voltage at the output of the comparator 6 is absent. As the train speed decreases, the electrodynamic deceleration efficiency drops sharply, which leads to a decrease in deceleration and, accordingly, the voltage on the resistor 4 to a value less than the reference voltage and. A logical unit is formed at the output of the comparator 6. Since the third input of the coincidence unit 7 also supplies voltage from speed sensor 1, a voltage is generated at its output that drives the pneumatic brake to switch on. However, switching on the uncontrolled pneumatic brake will simultaneously lead to a sharp increase in the train deceleration, forming a logical zero on the output of the comparator 6 and issuing a command to turn off the pneumatic brake 11. Entering the time delay element 12 by 0.5-1.0 s to turn off the pneumatic brake 11 ensures stable switching of the pneumatic brake until the train stops. After the train stops, the pneumatic brake 11 is disconnected due to the absence of voltage from the speed sensor 1 at the input of the circuit coincidence unit 7. If after this the train does not move, then the pneumatic brake 11

remains disconnected, thereby avoiding pressure losses in the pneumatic system. If the train began to move downhill, a voltage appears at all inputs of the coincidence unit 7, leading to pneumatic brake engagement. In the event of a failure of unit i, electrodynamic braking, the deceleration of the train is absent and a voltage appears at all inputs of block 7 of coincidence, leading to mechanical braking of the train. The level of retardation at which air brake 11 is activated is determined by the reference voltage Uo.

The transition from electrodynamic to mechanical braking applied to the device, depending on the actual deceleration of the train, ensures safe movement in the event of an electrodynamic brake failure, improves control of the braking efficiency, and excludes additional devices in the traction motor circuit.

The economic effect due to the increased reliability of braking will be 3-4 thousand rubles for an electric locomotive. in year.

Claims (1)

1. USSR author's certificate No. 651987, class; B 60 L 7/22, 1977 (prototype). Rfv k.