ME12002HYDRAULICSYSTEM

OperatinganAdditionalOptionWhile Driving(sidevalveblock)

Figure 3-156 Operation of Additional Option While Driving (side valve block)

Option control valve spool operates when controlling additional functions, and straight driving is maintained when pilot pressure from option control valve flows into port (35) of logic valve [e1]. Option control valve pilot pressure flows into port (35) of logic valve [e1]. Piston (301) then presses down while spring (621) and spring (622) force main relief valve (601) onto its seat within casing travel (101) (not shown), and path (34) shuts-off. Pilot path (18) and pilot path (19) pressurize for operating the straight travel control valve. See Figure 3-156.

SideValveBlockRegulation

PumpRegulation

If any side valve block function activates (dozer blade or arm swing), the pilot signal from the activated spool cap passes through shuttle valve block (22), and then through section arm 2. See Figure 3157.

The spool moves according to the pilot pressure, and the center bypass closes because of the spool movement.

Negative control valve (NR2) pressure decreases, and the decreased pressure signal activates the pump regulator, increasing pump capacity.

StraightTravelRegulation

The output pilot pressure from the shuttle valve block activates the logic valve e1 in the main valve block.