SU614983A1 - Antiskid device - Google Patents

Description

The invention relates to the field of brake systems of rail and trackless vehicles.

Devices for detecting skid, wheel speed sensors, pulse formers, actuating units based on the number of vehicle wheels, and a slip control unit lT | 2 are known.

It is known anti-buzzer, a device containing sensors for the rotation of the wheels connected via pulse shapers to the slip control unit, the outputs of which are connected to the inputs of the brake deactivation of the executive bodies | h |.

In this device, the cancellation of the skid signal is made according to the results of the relative slip control, while taking into account the possibility of simultaneous use of all the wheels (or wheelsets) of the vehicle, therefore the device does not provide reliable protection of the wheels against seizure, especially under poor adhesion conditions. A cancel signal can be made with a certain fixed delay after the iJbip signal of the signal. At low speeds, such a delay significantly increases the required.

The aim of the invention is to increase the reliability of jamming and the effectiveness of the brake system.

For this, the proposed device is equipped with controllable brake activation delay units connected between the slip control unit and the brake actuation inputs of the executive bodies, and the delay input of each of these blocks is connected to the output of the pulse driver; the controllable brake turn-on delay block contains a reversible counter, one-shot stand-by, self-oscillating hg-generator, inverters and logic elements, And, the summing input of the reversible counter is connected to the output of the logic element And, one of the inputs; which is the control input of the block, the subtracting input of the reversible counter is connected to the output of another logical element AND, one of which is connected to the output of the self-oscillating generator, another input of the first logical element AND directly and the other input of the second logical element AND through an inverter are connected to the output of the standby one-shot, the input of the latter is the input of the block, and the output of the block which is the output of the high discharge of the reversible counter is connected via another inverter to the third input of the watt cerned ion the NAND gate of FIG. 1 shows the basic block diagram of the proposed anti-device; in fig. 2 is a block diagram of a controllable brake turn-on delay block; in fig. 3 is a block diagram of a slip control unit.

The antiskid device consists of several identical channels (according to the number of wheels or wheel pairs of the vehicle). Each channel contains a sensor.

1 wheel speed, former

2 pulses (common for all channels), slip control unit 3, controllable brake activation unit 4

and the executive unit 5.

The controllable delayed control unit 4 (Fig. 2) contains a waiting single-cycle 6, a self-oscillating pulse generator 7 with a constant follow-up period, which can. be common to all controllable delay blocks, logic gates And 8 and 9, inverters 10 and 11, and a reversible counter 12;

The delay input of block 4 is the input of a standby one-channel-ora 6, control-1U-1M input — one of the inputs of the AND 8 gate. The output of block 4 is the output of the higher bit of a reversible counter 12. The output of the waiting one-shot 6 And 8, and through Inverx) p 1O - with one of the inputs of the logical element AND 9. The output of the logical element And 8 is connected to the summing input of the reversible counter .12, and the output of the logical element And 9 - with the subtractive input of this counter. The second and third inputs of the logic element And 9 are connected respectively to the output of the self-oscillating generator 7 and to the output of the higher discharge of counter 12 via the inverter 11 ..

The slip control unit 3 (Fig. 3) contains several (by the number of vehicle wheels) identical chains each of which consists of a serially connected input key 13, a counter 14, a decoder 15 and an output key 16. In addition, there are common

for all circuits, the logical element OR 17 and the distributor 18 control the signal signals. The inputs of the storage control unit 3 are the inputs of the keys 13 connected to the outputs of the corresponding drivers 2 (Fig. 3), and the outputs are the outputs of the keys 16. The first output of the decoder 15 is a signaling device for the end of the next control cycle, and the second output is a signaling device for the wheel , the first outputs of all decoders 15 are connected via an OR 17 gate to the input of the control signal distributor 18, which has three outputs: the first output is connected to the second inputs of keys 13, the second output - to the second inputs of keys 16 , the third output is with reset inputs to the initial state of the counters 14. The operation of the slip control unit occurs cyclically. Each center is organized by three control signals from the distributor 18.

 The device works as follows.

The rotational frequency sensor 1 produces an alternating voltage with a frequency proportional to the wheel rotational speed, shaper 2 converts this voltage into single-pole pulses, which are fed to the corresponding input of the slip control unit 3 and to the control input of the brake-activated control unit 4.

If the controlled wheel is in the state of use, then the slip control unit 3 generates a signal of input, which is fed to the brake opening input of the execution unit 5 and simultaneously to the delay input of the controllable delay unit 4 of the brake.

Claims (3)

According to the signal received at the brake release input, the executive unit 5 acts on the working element of the brake system in order to remove or reduce the braking force on the monitored wheel. The signal arriving at the same time, to the delay input of the unit 4, is delayed in this unit by time depending on the speed of rotation of the wheel, which it had at the time of generation of the yuz signal. Information about this speed comes in the form of pulses from the generator 2 to the control input of block 4 After the required time interval from the output of block 4 to the brake enable input of the executive unit 5, a signal is received, according to him block 5 acts on the working body to restore the braking angle: or np kpggg-o The operation of block 4 of the controllable delay of braking is as follows. The TZ initial position in the reversible counter 12 records the maximum number allowed by the digit of the counter. When a pulse arrives at the triggering input of the block from the slip control unit 3, indicating the presence of a controlled wheel, start the waiting one-shot 6, generating a single impulse of a given duration. This pulse is resolved by it for passing through the AND 8 gate to the summing input of the reversing counter 12 pulses from the generator 2 connected to the rotational speed sensor 1. The first of the indicated: pulses will transfer the counter to the zero state; subsequent pulses are added up until the single pulse of the waiting one-shot 6 stops. For a period of time equal to the duration of the pulse of the one-shot, a certain code characterizing the frequency of rotation of the wheel being monitored will be recorded in the reversing counter 12. The termination of the one-shot impulse 6, as well as the presence of a certain code in the counter 12, different from the initial one, causes that through the logic element AND 9 to the subtractive input of the counter 12 pulses start to flow with a constant period from the auto-oscillator 7. Subtraction It takes until the counter 12 is in the initial state, which is a condition for the actuator to turn on the brake and at the same time stop the supply of the subtracted pulses from the generator 7 through a logical element 9. 9. The brake start delay is proportional to the speed of rotation of the wheel at the time when the signal is produced. The number of bits of the reversible counter 12 is determined based on a selected number of sites for a stepwise approximation of the desired functional relationship. In the prototype, eight approximation plots were taken, which correspond to three bits of the binary counter. To decipher the state of the counter, a fourth (senior) bit has been added, registering the overflow of the three previous bits, which is formed as a result of the subtraction, and is simultaneously the initial state of the counter and the signal to activate the brake. Indication of the state of the counter can be performed in another way, for example, with the help of a descrambler. The duration t c pulse generated by the waiting one-shot 6, is calculated; , according to the formula: Db, where D.8 is the length of the path traveled by the vehicle wheel, corresponding to one period of oscillation of the voltage generated by the rotational speed sensor; Vj is the approximation step of the required functional dependence of the delay of the signal cancellation on the skid on the peripheral speed of the wheel at the moment of brake deactivation. The period T of the impulse following from the self-oscillating generator 7 is calculated according to the formula i ", to where 15 dd is the maximum required for the brake actuation center corresponding to the maximum speed of the vehicle; K - the number of areas of approximation of functional dependence. When changing the specified parameters (for example, when changing the vehicle or changing coupling conditions), the new calculated value of the proportionality coefficient in this functional dependence is achieved, as follows from the principle of operation of block 4 of the controlled delay, by changing the period T of pulses from the generator 7 Proper installation of this period avoids the risk of jamming the wheels of the vehicle while they are simultaneously using and unjustifiably increasing the stopping distance observed by the vehicle. It is used when using devices with a constant brake activation delay. In block 3 of the slip control, each cycle of operation is organized by three control signals from the distributor 18 (Fig. 3). The first control signal Counting enters the second inputs of the keys 13 and ensures the passage of pulses from the wheel speed sensors to the corresponding counters 14, which count these impulses until one of the counters dials a certain number in advance. In this case, from the first output of the decipheror 15, through the OR element 17, the input of the distributor 18 receives a signal, in response to which the distributor 18 stops the production of the first control signal,. Counting, and generating the second control ciirHarfCtapoc j, is sent to the second inputs of keys 16 at a time. If in some of the counters 14 there is a recorded mevier number than some predetermined number, then the second output of the corresponding decoder 15 is a signal, which is transmitted via key 16 to the actuators disabling this wheel. Then, the distributor 18 generates the third control signal. Reset arriving at the counters 14 and resetting them to the initial state, after which the first control signal Counting is generated. The counting starts the setting of the slip control cycle. the device allows to increase the reliability of the wheel seams against damage and to increase the efficiency of the braking system. Claims. Counter device containing wheel speed sensors connected via pulse shapers to a slip control unit, the outputs of which are connected to the brake open inputs of the executive bodies, characterized in that, in order to achieve reliability, the brake system is jammed and the efficiency of the brake system 1 is reliably secured. it is equipped with locks of controllable activation deceleration of the brake locks connected between the block of sliding control and inputs of the brake switch actuators, and the delay input of each of these blocks connected to the output of the pulse generator. 2. The device according to claim 1, which is different from the fact that the control unit (brake delays) contains a reversible counter, a waiting one-shot, self-oscillator, inverters and logic elements, And, the summing input of the reversible counter is connected to the output And, one of the inputs of which is the control input of the block, the subtracting input of the reversible counter is connected to the output of another logical element And, one of the inputs of KOTtDporo is connected to the output of the self-oscillating generator, the other input of the first l And then another input of the second logic element AND is connected via an inverter to the output of a waiting one-shot, the input of the latter is the input of a block, and the output of a block is an output of a higher-order bit and a reversible counter is connected via another inverter to the third input 1 of the second logical element AND Sources of information taken into account in the examination; 1. US patent number 383Y89, CL ZOZ-21, 1974. 2. The patent of France No. 2227162 cl. In 61 with 15 / O8, 1974. 3.B. I. Egorov, V. S. Roslanas. Discrete device for detecting skid and wheelset stacking. Electric and thermal g ha. 1972, No. 6., - p. 37-38, fi j u