2.2.2. IMPLEMENT SECTION Hyd. Block Ass'y [3510(H)-EU, TH]
GENERAL
SAFETY FIRST
HYDRAULIC SYSTEM - STRUCTURE AND OPERATING PRINCIPLE
NJI FP
ENGINE
3
6 4
*HDU UDWLR
$ %
%220
%8&.(7
$ %
2
+\G )LOWHU
6
Loader Joystick Valve Ass'y [US, AU, 4010(H)-EU]
Rear Aux. Valve Ass'y 'RZQ 6SHHG &RQWURO 9DOYH
REAR HSTAXLE
Position Control Valve
5
8QORDG 9DOYH
Dealer Copy -- Not for Resale
3
&\OLQGHU
&UDQNLQJ NJI FP
3RSSHW 9DOYH
6SRRO
REAR BRAKE AXLE
$ %
OSP NJI FP
OSP
1
$ % *HDU SXPS
FF UHY FF UHY
(1*,1(
TRANSMI SSION HST
TRANSMI SSION TRANSMISSION
CLUTCH
Steering unit
6DIHW\ 5HOLHI
A/C AND INDEX HEATER
HYDRAULIC ELECTRIC & DIAGNOSIS SYSTEM
HYDRAULIC STEERING SYSTEM
STEERING SYSTEM FRONT AXLE
FRONT BRAKE AXLE
R72WB16B
Hydraulic fluid in the implement line flows in the following order: filter (1) → pump (2) → main relief valve (6) → hydraulic block (3), joystick valve (3) → remote hydraulic valve (4) → lift control valve (5). If hydraulic fluid is used in a certain step, it cannot be used in the following step. For example, the remote hydraulic valve and lift cylinder cannot be used at the same time. Therefore, the remote hydraulic valve should be firstly checked if it is properly operated if the lifting arm does not operate. Hydraulic pressure of the implement line is controlled by the main relief valve, which is installed to the hydraulic block (joystick valve), to 185 kgf/cm² (18,130 kPa / 2,631 psi). Therefore, when pressure in the circuit rises over the relief pressure due to overload for the operation of the remote hydraulic valve and lifting cylinder, the relief valve is open to protect the circuit. When the engine is running at the rated speed (2,600 rpm), the secondary gear pump with the capacity of 26 L/min (6.87 U.S. gal) is operated to supply hydraulic oil to the loader hydraulic block (joystick valve) (3), remote hydraulic valve (4) and lift control valve (5) mainly for tractor work. Hydraulic oil is firstly supplied to the hydraulic block (joystick valve) after passing through the oil filter and secondary gear pump from the transmission case. Then, for loader operation, hydraulic oil is supplied to the loader through the outlet port. Oil returned from the loader cylinder is led back to the transmission case through this port. When the hydraulic block (joystick valve) is not in use, hydraulic oil is supplied to the next component, remote hydraulic valve, through the carryover line in the valve. The above circuit diagram shows two double acting valves. If any one of two double acting valves is in use, the threepoint hydraulic cylinder behind this step cannot be operated. When the remote hydraulic valve is not in use, hydraulic oil is supplied to the lift control valve through the carryover line to operate the three-point link. When lifting the lift arm, hydraulic oil is supplied to the hydraulic cylinder. When lowering or stopping the lift arm, oil supplied to the valve and drained from the hydraulic cylinder is returned to the transmission case.
11-8292 of 450
DR72-W00
