SU1678670A1 - Electropneumatic brake system of trasport vehicle - Google Patents

Description

one

(21) 4723773/11

(22) 07.26.89

(46) 09/23/1. Bul No. 35

(71) Scientific and Production Association

on tractor NATI

(72) E.V.Kinshakova

(53) 629.113-59 (088.8)

(56) USSR Copyright Certificate Ms 1423443, cl. B 60 T 13/68, 1987.

(54) ELECTROPNEUMATIC BRAKE VEHICLE SYSTEM

(57) The invention relates to automotive engineering. The purpose of the invention is to simplify the design. Electromagnetic Modulator 4 Electropneumatic Control

the braking system of the vehicle consists in obtaining, using a sensor 3, an electrical signal proportional to the intensity of braking, as specified by the driver, determining the derivative of this signal in time using the differentiator 9, generating electrical impulses using the pulse width modulation method,

acting on modulator 4. In this case, in scheme 11, the absolute value of said derivative is extracted, which is converted into a series of pulses with a duration varying in proportion to the absolute value of this derivative. 1 il.

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This invention relates to the field of automotive building engineering.

The purpose of the invention is to simplify the design.

The drawing shows a functional diagram of an electropneumatic brake system.

The vehicle's electropneumatic braking system contains a receiver 1, which serves as a source of compressed air for braking mechanisms, a brake pedal 2 with a sensor 3 for its movement, which is a unit for deceleration intensity, an electromagnetic three-phase pressure modulator 4 with filling electromagnets 5 and a relief 6, brake chambers 7, an electronic unit (ECU) control 8, the input of which is connected to the sensor 3, and the outputs - with the electromagnets 5 and 6 of the modulator. The ECU 8 comprises a differentiator 9, a pulse-width converter (PLC) 10 connected to the output of an absolute value allocation circuit 11 connected to an input of differentiator 9. The latter is connected to the input of threshold element 12 connected to the control input of switch 13, an information input of which is connected to the SHIP 10. The outputs of the switch 13 are connected to electromagnets 5 and 6 of the modulator 4.

The electro-pneumatic braking system works as follows.

In the non-brake driving mode, the brake pedal 2 is released, the electrical signal from sensor 3 is zero, at both outputs of the ECU 8 there are no electrical signals, therefore, the modulator 4 occupies a neutral middle position at which the brake chambers are separated from both the receiver and the atmosphere.

When the driver acts on the brake pedal 2, an electric signal U, proportional to its movement, from sensor 3 is fed to the input of differentiator 9, the output of which forms the first derivative of the said signal over time

-t-- -. Differentiated signal through

the absolute value extraction circuit 11 is fed to the input of the SCI 10, the output of which produces a series of pulses with a duration varying in proportion to the absolute value dU

derivative

. A series of pulses is fed to the information input of the switch 13, to the control input of which a signal is output from the output of the threshold element 12, having a threshold level A.

different from zero, but close to it, which can be both negative and positive.

If we accept the threshold level A, for example, negative, then in the braking mode

dU

differentiator 9 derivative

dt

0

five

0

five

with a positive sign at the output of the element 12, a logical 1 appears, which acts on the control input of the switch 13. The latter connects the information input of the switch 13 to its output connected to the filling electromagnet 5 of the modulator 4.

Thus, a series of pulses produced by TLC 10 switches the modulator 4 during the pulse to the leftmost position connecting the brake chambers 7 with the receiver 1, and during the pause - to the middle position, which interrupts communication with the receiver and provides pressure hold . In service braking mode, when the brake pedal is moved and it takes a certain position,

d u

is zero therefore

signal

dt

the output of the element 12 remains logical 1 and the information input of the switch 13 continues to communicate with the electromagnet 5 of the modulator 4. Since in this case a zero signal is received at the input of the CHINA 10, a zero signal is generated at the output of the CHIP 10 The electromagnet 5 of the modulator 4, switches the latter to the middle position, providing a pressure holding phase. When ottormazhivani.i derivative

-. - 0 and when decreasing its value

below the threshold level A at the output of the element 12, a logical O is formed, which, acting on the control input

the switch 13 connects the information input of the latter to its output associated with the electromagnet 6. In this case, the modulator 4 switches to the extreme right position when another pulse arrives from the SHIP 10 output to the electromagnet 6. As a result, the brake chambers are connected to the atmosphere, providing - braking of the vehicle, during the absence of a pulse on the electromagnet 6, the modulator 4 takes the middle position, carried out the pressure holding phase.

Claims (1)

Claims of an Electropneumatic Brake System of a Vehicle Containing a receiver connected to the brake circuit by means of a three-phase pressure modulator, having two control electromagnets connected by windings to the outputs of the control unit, to the input of which is connected to the output of the brake intensity regulator, characterized by. that, in order to simplify the construction, the control unit is made of a differentiator, whose input is an input block control, and the output is connected to the inputs of the threshold element and the absolute value allocation circuits, the output of which is connected to the input of a pulse-width converter connected by an output to the information input of the switch, the outputs of which are the outputs of the control unit, and the control input is connected to the output of the threshold an item.