End Control Plate Of Ehs Working Sections; Hydraulic System Of Fll Control; General Information - Belarus 3522.5 Operator's Manual

3.16.4.2 End control plate of EHS working sections

The position of center slide-valve is permanently controlled on a signal of inductive displace-
ment pick-up (see figure 3.16.8) of center slide-vale and if it is necessary are made corrections in
control signal, which is sent to proportional electromagnet valve that regulate control pressure. The
sensor has central master primary coil and signal secondary coils. At movement of coil rod, which is
mechanically connected with center slide-valve, electrical signal in signal coins is changed, than sig-
nal is handled by built-in electronic card and then is developed correction signal. For control of EHS
working sections is used special end plate with electrical control of cross-over reducer valve (figure
3.16.11). The valve serve for pressure feed in EHS control system.
At the beginning of valve travel the pressure is increased with a help of electrically controlled
reduction valve. Switching command is sent by control lever shifting (for example joystick). The
pressure in the system is reduced between 0,21 and 0,24 MPa. The valve has emergency shutdown
system (pressure decrease), that gives a possibility to return slide-valve of working section in neutral
position in emergency situation.
Fine filter
Valve for pressure
decrease
Figure 3.16.11 – Control scheme of EHS working sections with cross-over reduction
valve

3.16.5 Hydraulic system of FLL control

3.16.5.1 General information

The tractors BELARUS-3522.5 are equipped with automatic control system of front lift link-
age (FLL), using position control method. As actuator is used electrohydraulic regulator EHR-5LS of
the company Bosch, its design and basic circuit diagrams are shown in figure 3.16.12. As position
sensor is used angular sensor of the same company with angle ± 41˚of lift linkage position control.
The sensor is driven by lever system from lift link. The sensor is installed to the right along tractor
movement in special hole in bracket of front lift linkage. Lever control of the sensor is fixed on the
one side by cotter pin on sensor end and on the other side on draft link with a help of nuts and pin.
The rules of FLL control are described in section 2.15 "Front lift linkage control".
Figure 3.16.12 –Electrohydraulic regulator EHR-5LS
Actuating electromagnet
Coarse mesh filter
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Fine filter
Actuating
electromagnet
3522.5-0000010 РЭ
Valve for pressure
decrease
Coarse mesh filter