GSi InterSystems STP, Руководство пользователя

Страница: 18 / 40

17
4.3 Hydraulic Components
4.3.1 Solenoid Valves V-1, V-2, V-3, & V-4
These valves are 4-way, 3-position, double-solenoid operated, spring-centered directional control valves. When both
solenoids of a valve are de-energized, the valve spool is spring-centered and hydraulic fluid is routed directly into the
manifold's return passage.
Each solenoid valve also has a manual operator that can be used to physically shift the valve spool. If a valve does
not operate when the associated control switch is actuated, depressing the manual operator with a ball-point pen or a
screwdriver will cause the valve to shift. If the valve shifts, it can be determined that the problem is in electrical circuit
or solenoid.
The electrical connections to the solenoids are accessible by removing the cover of the terminal box on each valve.
The valves are pre-wired to the electrical junction box inside the hydraulic power unit.
Refer to the certified drawings for additional valve information.
4.3.1.1 Boom UP/DOWN Valve V-1
This solenoid-operated directional control valve alternately pressurizes the piston end and rod end of the double-
acting cylinder to raise and lower the boom. When the valve's "A" solenoid is energized, the valve spool shifts,
pressurizing the piston end of the cylinder, thus raising the boom. When the "B" solenoid is energized, the valve
spool shifts, pressurizing the rod end of the cylinder, thus lowering the boom. Note, when neither "A" nor "B"
solenoid is energized the valve is spring centered so that all ports are blocked and movement is inhibited.
4.3.1.2 Counter Balance Valve V-12
When at rest, the probe’s weight causes static hydraulic pressure. The purpose of the Counter Balance Valve is to
prevent the probe from free ‐ falling slightly when the probe is initially powered down. The counter balance valve
also prevents the probe from drifting down. If the probe drifts down, the counter balance valve will need to be
adjusted as follows:
NOTE: Prior to performing the Counter Balance Valve adjustment, first verify that the UP port, as shown on the
power unit decal, is actually the up hose. If not, the UP and DOWN hoses and the control wires must be
reversed.
4.3.1.2.1 Counter Balance Valve adjustment:
A. Turn ON the pump and raise the boom half way up (horizontal), extend the boom all the way out. Turn OFF
the Pump.
B. Push IN on the DOWN OVERRIDE SPOOL, on the UP/DOWN Directional Control Valve. This is the valve’s
bottom override as looking inside the Hydraulic Power Unit.
C. While pressing in on the DOWN override, turn the Counterbalance Valve’s adjusting screw Clock Wise (CW),
to lower the pressure, until the boom just begins to drop. Slowly turn the screw CCW until the boom stops
lowering. Turn the adjustment screw an additional ¼ turn CCW.
D. The Counterbalance is adjusted. If there is a problem probing down into the material, the system pressure
may need to be increased in small increments until the probe operates normally. After each small increase
in pressure, monitor the system pressure by deadheading the probe in the down position. DO NOT EXCEED
THE RECCOMENDED SYSTEM PRESSURE. If the pressure was increased, the LEFT/RIGHT flow controls may
need to be readjusted.