SU1654068A1 - Road train brake system - Google Patents

Abstract

The invention relates to transport engineering and relates to vehicle brake drives, namely, a retarder engine brake and its connections to the working brake system of an articulated train. The purpose of the invention is to increase the efficiency of the system. The system is equipped with an electronic control unit, the inputs of which are connected to a tachometer, a switch and a pressure sensor, and the output is connected to an electromagnetic actuator of a valve controlling cylinders and a pressure reducing valve. The design of the system provides the mode of automatic maintenance of the optimal speed of movement of the articulated vehicle on a slope of 2 Cp. 2 yl

Description

FIELD OF THE INVENTION The invention relates to the transport engineering industry and relates to the brake drives of vehicles, namely, the retarder engine brake and its connections to the working brake system of the trailer train.

The purpose of the invention is to increase the efficiency of the system.

Fig 1 shows a functional diagram of the braking system of the articulated vehicle; in fig. 2 - functional diagram of the electronic control unit.

The brake train system (Fig. 1) contains the receiver 1 of the rear axle circuit of the brake pneumatic actuator, the receiver 2 additional consumers, the combined brake valve 3, two-wire trailer brake control valve 4, two-main valve 4, pressure reducing valve 6, cylinder 7 of fuel supply shutdown, throttle control cylinder 8, brake pedal 9 electronic control unit (ECU) 10. the first three inputs of which are connected to the outputs of a three-phase tachometer 11 also connected to the inputs of a tachometer 12, and four The mouth input is connected to the first contact of a normally closed switch 13, mounted on a brake pedal 9, rigidly connected to a button 14 protruding above the surface of the pedal. The fourth input of the ECU 10 is connected to the first contact of a normally-open pneumoelectric pressure sensor 15 installed in the output line 16 of the upper section of the brake valve, and the output is connected to the control winding of the solenoid valve (EMC) 17. in the normal position of which are cylinders 7 and 8, and the reducing valve 6 also communicates with the atmosphere and, in its active state, with the receiver 2. The control winding of the EMC 17 is connected, in addition, with the button 18, which, when influenced, controls the electric winding of the EMC 17 Itani.

In addition, there is an electrical connector 19 through which the second contact

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pneumatic sensor 15 communicates with the housing.

The ECU 10 (Fig. 2) contains three one-shot 20-22, the inputs of which are connected to the outputs of the sensor 11, and the outputs to the inputs of the element OR 23, the output of which, in turn, is connected to the input of the frequency converter - voltage (PCN) 24, with the output of the PLN connected to the input of the comparator 25 with a hysteresis, the output of which is connected to the first input of the logic element 25, the second input of which receives a signal from the delay element 27, the input of which is connected to the switch 13 mounted on the brake pedal and a pneumatic sensor 15. Logic outputs th element 26 is connected to the input of the amplifier 28, the power output is connected to EMC 17.

In the absence of action on the button 14 and the brake pedal 9, the pressure in the output line 16 in the upper section of the brake valve 3 is absent, the first and second contacts of the pneumatic sensor 15 are open, and the first and second contacts of the switch 13 are closed. In this case, the fourth input of the ECU 10 is connected to the housing via a switch 13, i.e. with zero power supply, which contributes to a low logic level. At a low logic level, at the fourth input of the ECU 10, at its output there is no control signal for the EMC 17, regardless of the frequency of the pulses coming from the tacho sensor. If there is no effect on the button 18, the control winding of the EMC 17 is de-energized. The EHR is in its normal position, in which the cylinders 7 and 8, as well as the pressure reducing valve 6 communicate with the atmosphere, the braking system does not work.

If it is necessary, for example, on a long descent, to activate the auxiliary brake system (ATS). it is necessary to act on the button 14, with which the switch 13 is rigidly connected. the force required to switch the switch 13 is incomparably less than the force required to move the pedal 9, the latter remains in the depressed state. Now, the fourth input of the ECU 10 is disconnected from the housing, and the ECU 10, analyzes the frequency of rotation of the engine according to the frequency of the pulses received from the tachometer. In this case, if the engine rotational speed at the moment of impact on the button 14 is below the critical ECU 10, the control signal does not give a control signal to the EMC 17, the critical frequency of the engine rotation for the PTS is the frequency at which the PTS operation turns out

inefficient, as well as difficult to restart the engine spontaneously after turning off the PTS

With a correctly selected rate of movement and a correctly chosen gear, the engine rotation frequency at the moment of turning on the PTS should be higher than the critical one. The ECU 10 at the same time with a delay of 0.2-0.3 s generates a control signal at the output of the EMC 17.

0 EMC 17 takes up its active state in which the cylinders 7 and 8, as well as the reducing valve b, are in communication with receiver 2. Compressed air from receiver 2 begins to flow into the cylinders.

5 7 and 8, as well as through the reducing valve 6 and the two-main valve 5 - R controlling valve cavity 4. As the pressure increases, the working cylinder 7 stops supplying the fuel to the engine, and cylinder 8

0 includes an after-run damper in the exhaust manifold, providing braking for the traction. The presence of pressure in the control cavity of the valve 4 ensures the supply of the control signal from step 5 to 4 to the trailer braking system, restrict the trailer's efficiency to the reduction gear valve 6 (# 1.5 atm). In this way, the PTS provides a braking condition for the vehicle and the corresponding trailer life, which does not require a special equipped trailer.

When the gear is correctly turned on, the inclusion of the PTS causes a train to slow down the train. The turnover drops when they decrease to a critical non-value, the ECU 10 removes the control signal from the EMC 17. The operating cylinders / and 8, as well as the pressure reducing valve 6, appear

0 communicated with the atmosphere. The throttle valve is turned off, the fuel supply is turned on, the control signal is applied to the braking system; v the trailer The auto train starts acceleration. The engine 5 of the engine grows when they reach the optimum value (at which the military-technical cooperation is most effective). The ECU 10 again signals the EMI 17. The entire process described above is repeated. If a

0, the effectiveness of the PTS is insufficient for slowing down an articulated train, the body acts on the pedal 9, which is rigidly connected to the brake crane 3. There is a lift in the output line 16 of the crane. This causes the contacts of the pneumatic switch 15 to close, the fourth input of the ECU 10 is connected to the housing, i.e. a low logic level is set on it. The ECU 10 removes the control signal from the EMC 17, i.e.

turning on the service brake system, the PTS is turned off.

When the service braking system is turned on, without first switching on the PTS, the driver acts on the brake pedal and simultaneously acts on button 14. However, due to the fact that at the output of the ECU 10, the control signal appears 0.2-0.3 s after opening switch 13, the PTS is not turned on, because During this time, the pressure in the output line 16 of the crane 3 has time to increase. which leads to the closure of the contacts of the switch 15, and the fourth input of the ECU 10 again communicates with the housing.

When driving without a trailer, the plug 19 disconnects the second contact of the pneumatic switch 15 from the casing, therefore, it becomes possible for the PTS and the service braking system to work together.

At low braking intensity, braking torques from the PTS and the service braking system add up. This reduces the load on the working brake system and increases the service life of the brake pads.

With intensive braking, the PTS has an anti-blocking effect, which increases traffic safety.

In addition, the PTS can be turned on using the PTS push button 18, which connects the EMC 18 to the power supply. This mode can be used both for braking the articulated vehicle and for engine jamming.

The ECU 10 (FIG. 2) operates as follows. The fourth input of the ECU 10 is connected to the switch 13 and the sensor 15 (FIG. 1), by means of which it can be connected to the housing or disconnected from it. This signal is fed to the input of the delay element 27, which includes a resistor 29, a capacitor 30 and a comparator 31. When the fourth input of the ECU 10 is connected to the housing. the capacitor 30 is discharged, at the output of the comparator 31 - a low logic level. When the fourth input of the ECU 10 is disconnected from the housing, the capacitor 30 starts charging through the resistor 29. As soon as the voltage on the capacitor 30 exceeds the threshold of the comparator 31, a high logic level is set at the output of the latter. The parameters of the time of the master circuit are chosen such that the capacitor 30 is charged before the trigger voltage of the comparator 31 for 0.2-0.3 sec. From the delay element 27, the signal arrives at one of the inputs of the And 26 element. At the output of the And 26 element, a high logic level when both of its inputs receive signals of high

logical level Thus, when the fourth input of the ECU 10 is in communication with the housing, the output of the element 26 has a logic low, regardless of the level

the signal from the comparator 26 arriving at the other input of the element I 26. When the fourth input of the ECU 10 is disconnected from the housing, the signal level at the output of the element 26 depends on the signal level from the comparator 25.

0Incoming the first three inputs of the computer

10, the signals from the tachometer 11 are fed to one-shot 20-22. which are formed from the pulses produced by the tachometer, pulses of a certain amplitude and

5 duration. Pulses from one-shot 20-22 are fed to the inputs of the element OR 23. A high logic level is set at its output if a high-level signal is present at least one of the inputs. Since the pulses produced by the tachometer 11. as well as the pulses at the outputs of the single vibrators are shifted relative to each other in phase, the output of the OR element 23 has a sequence of pulses, the frequency of which is proportional to the rotation frequency of the tachometer 11.

Element OR 23 pulses are fed to frequency-voltage converter 24, the signal level at the output of which is proportional to the frequency of pulses arriving at its input.

So, 1 way, to the input of the comparator 25. having a switching characteristic with hysteresis, a signal is received, the level of which is proportional to the rotation frequency of the tachometer 11. i.e. ultimately engine speed.

The comparator 25 has two threshold

0 level: upper, the value of which is equal to the signal level from converter 24 at the optimum engine speed (frequency at which the use of the PTS is most effective), and the lower value of which is equal to the signal level from the output of converter 24 at the critical frequency of engine rotation (frequency, in which the use of the PTS is ineffective, and the spontaneous restart of the engine,

0 when turning off the PTS, difficult).

When the signal level at the input of the comparator 25 rises from some minimum value, its logic level remains low, while the level

5 signal at the input does not reach the value of the upper threshold level. With a further increase in the level of the input signal at the output of the comparator, the logic level remains high. When reducing the input signal is less than the upper threshold level

at the output of the comparator, the logical level is kept high until the input signal is below the lower threshold level.

Thus, at the output of the comparator 25, a high logic level is established when the engine speed reaches an optimum value, and a low logic level, when the engine speed is reduced to a critical value.

If the element 26 is supplied from the delay element 27 by a high logic level signal, the signal from the comparator 25 is supplied through the element 26 to the power amplifier 28, from which the control signal is fed to the control winding of the EMC 17.

Claims (3)

Invention Formula 1, The braking system of the articulated trailer containing receivers connected to the brake circuits of the tractor and the control cavities of the trailer brake control valve in a two-wire circuit by means of a combined brake valve controlled by a pedal, a pressure sensor with normally open contacts for closing the connected electric circuit the body, the auxiliary brake control line, is selectively connected to the atmosphere and the receiver by means of a control valve, and connected to the specified line enes cylinders controlling the throttle and the fuel supply in the internal combustion engine, the output shaft of which is equipped with a three-phase tachosensor, and one of the brake control valve cavities trailer via dual line valve, characterized in that, in order to increase the system efficiency, it 0 five 0 five 0 five equipped with a reducing valve installed at the inlet of a two-line valve connected to the auxiliary brake control line, an electronic control unit and a normally-closed switch with a pedal control button connected in parallel to an electrical circuit connected to a pressure sensor pneumatically connected to the brake valve section communicated through the other inlet of the two-trunk valve with the corresponding control cavity of the trailer brake control valve, and the control valve formed with the electromagnetic actuator, wherein the control unit comprises three monostable multivibrator whose inputs are connected to respective outputs tahodat- snip. and outputs with the inputs of the OR element, whose output through a frequency-voltage converter is connected to the comparator input with a hysteresis, a delay element to the input of which an electrical circuit connected to the pressure sensor and a switch, and an AND element whose inputs are connected to the outputs of the delay element and a comparator, and the output through the power amplifier is connected to the power supply circuit of the electric actuator of the control valve. 2. The system according to claim 1. characterized in that it is provided with an electrical connector for connecting a pressure sensor contact to the housing. 3. The system according to claim 1, characterized in that it is provided with a switch with a control button for independent power supply of the electromagnetic actuator of the control valve. GZ-KK . To brake on the axis of the axis "I Kg / Board f trailer brakes Fig f FIG. 2