40 - 3
Operation
The assembly of the pilot pressure control valve is shown on
page 40 - 2.
The pressure reduction unit is comprised of spools
17
,
pressure control springs
14
, return springs
15
, spring seats
13
and split washers
12
. The spools
17
are held against the
plungers
11
by the return springs
15
. When the control
handle is tilted, the plungers
11
move down, depressing the
return spring seats
13
, simultaneously compressing the
pressure control springs
14
, moving the spool, allowing
hydraulic oil to flow to the designated pilot port.
The lower end of the main body
1
contains the main inlet
port
P
, outlet port
T
to tank and the pilot pressure outlet
ports
1
,
2
,
3
and
4
.
The pilot pressure controls the stroke and direction of the
main control valve spools. This is achieved by providing a
spring at one end of the main control valve spools and
applying pilot pressure to the opposite end. (In some cases,
pilot pressure is applied to both ends of the control valve
spool.)
Function
Oil supplied by the hydraulic pilot pump enters at port
P
and
the function of the spools
17
is to direct oil from the inlet
port
P
to the output ports
1
,
2
,
3
and
4
or alternatively, to the
exhaust port
T
to tank. The pressure control springs
14
act
on the spools
17
to determine pressure at each port.
Plungers
11
slide in the guides
8
to vary the compression in
the springs
14
. The control handle, fixed to the adjusting nut
24
and circular rocker plate
25
is operated to move the
plungers
11
. The control handle is able to rotate 360° around
the knuckle joint
26
.
The return springs
15
operate between the casing
1
and the
seats
13
, regardless of the outlet pilot pressure, returning the
plungers
11
to their outer positions, ensuring the spools
17
return to their neutral (closed) positions. The springs
15
also
provide a resistive force, giving the operator a ‘tactile feel’ of
the controls.
Section E
Hydraulics
9803/6410
Section E
40 - 3
Issue 1
Remote Control Valve (Services)
Summary of Contents for JS130
Page 65: ...Section 3 Section 3 9803 6410 Issue 1 9 1 9 1 Routine Maintenance Component Location Diagram...
Page 118: ......
Page 119: ...3 1 Section C Electrics 9803 6410 Section C 3 1 Issue 1 Layout Operator s Cab...
Page 142: ...5 3 Section C Electrics 9803 6410 Section C 5 3 Issue 1 Pump Control FLOW CHART...
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Page 209: ......
Page 210: ...3 4 Section E Hydraulics 9803 6410 Section E 3 4 Issue 2 Schematics Shuttle Block...
Page 532: ...Contents Page No Technical Data 1 1 i Engine 9803 6410 i Issue 1 Section K Section K...