Hydraulic Schematics - Snorkel A38E Parts & Service Manual

6.2. Hydraulic Schematics

REFERENCE NAME
BRK Brake.
CLRV Cross-line
relief valve.
CV Check Valve.
CYL1 Lower boom lift Provides the force to lift the
cylinder.
CYL2 Upper boom lift Provide the force to lift the
cylinder.
CYL3 Tlelscopic
cylinder.
CYL4 Steering
cylinder.
CYL5 Master levelling Provides the pressure to the
cylinder.
CYL6 Slave levelling
cylinder.
FL1 Return line
filter.
(10 Micron)
HP Handpump.
MMB Main manifold
block.
MOT1 Slew Motor.
MP Motor/Pump
set.
V1 Brake oil
supply valve.
V2 Brake valve.
V3 Pressure
reduction valve. excess of 100 Bar entering
V4 Slew Directional Send oil to the left or right
Control Valve.
V5 Steer
Directional
Control Valve.
V6 Tele
Directional
Control Valve.
V7 Boom2
Directional
Control Valve.
V8 Boom1
Directional
Control Valve.
V9 Levelling
Directional
Control Valve.
AB38 Work Platform
Table 6-2: Hydraulic Schematic Legend
FUNCTION LOCATION
Spring applied - hydraulically On front end of
released brakes to stop wheel drive
rotation of drive wheels. motors on
(Set at 100 Bar). chassis.
To limit the max. operating On main
pressure of the slew motor. manifold block.
(Set at 50 Bar).
To prevent oil pressure in the On main
brake line from being lost manifold block.
through the main pressure
line.
Foward of first
lower boom - Boom1. post
Behind second
upper boom - Boom2. post
Provides the force to Inside Boom2
push/pull the tele-boom & Tele boom.
- Boom3.
Provides the force to Inside front of
push/pull the steering torque chassis.
arms.
Behind the
slave cylinder for cage second post
levelling.
Provides the force to level Close to cage
the cage up/down. pivot at inner
Tele boom.
Continuously filters hydraulic On top of the
return oil. hydraulic
reservoir.
Used for retraction of tele On side of
boom in the case of power manifold block.
failure. Delivers 15cc/stroke.
Contains the directional On hydraulic
control valves and relief reservoir in
valves that distribute oil to chassis.
the various functions and
control the operating
pressures.
Drives slew bearings drive Connected to
pinion. drive pinion.
Gear pump close coupled to On chassis.
D.C electric motor. Provides
pressurised oil flow for all
hydraulic functions.
This valve is energised to On main
allow oil into the brake manifold block
release chamber.
When energised this valve On main
prevents the pressurised manifold block.
brake oil from venting back
to tank. When the machine is
stationary this valve
de-energises and the brake
oil vents to tank and the
brake springs apply
themselves and keep the
machine stationary.
Prevents pressures in On main
manifold block.
the brake chambers.
On main
side of the slew motor. manifold block.
Send oil to the annular or full- On main
bore side of the steering manifold block.
cylinder.
Send oil to the annular or full- On main
bore side of the telescopic manifold block.
cylinder.
Send oil to the annular or full- On main
bore side of the Boom2 manifold block.
cylinder.
Send oil to the annular or full- On main
bore side of the Boom1 manifold block.
cylinder.
Send oil to the annular or full- On main
bore side of the levelling manifold block.
cylinders.
Schematics
REFERENCE
V10 (RV)
V11
V12
V13
V14
V15
Notes:
1. All of the Overcentre Valves represented within
this schematic have a 5:1 Pilot Ratio.
2. The P/O Check Valve represented has a 3:1
Pilot Ratio.
3. The maximum flow rate of the Pump/Motor Unit
is limited to 15 L/min @ 100% speed. Although
it should be noted that the actual flow rate will
depend on the applied load and the D.C. Motor
speed.
4. The maximum 'Return' flow rates for each of
the functions are restricted to the following
values;
l
Slew...
l
Boom1...
l
Boom2...
l
Tele...
l
Steering...
NAME FUNCTION
Main relief Sets max system pressure to On main
valve. 145 Bar
Single Prevents back flow and
Overcentre provides a hydraulic lock on
valve. the cylinder.
Emergency Allows upper and lower boom
lowering valve. to be manually lowered.
Pilot operated Holds tele cylinder in position On base of
check valve. after controls are released
Dual Holds pressure in
Overcentre master/slave closed circuit
valve. and provides host burst
protection. (Set 160 Bar).
Dual Holds pressure in slave
Overcentre cylinder and provides host
valve. burst protection.
(Set 120 Bar).
4 L/min
8 L/min
5 L/min
5 L/min
6 L/min.
Section
6.2
LOCATION
manifold block.
On base of
upper, lower &
tele cylinders.
On base of
upper and lower
cylinders.
tele cylinder.
On base of
master cylinder.
On base of
slave cylinder.
6-9