9 HYDRAULIC LIFT UNIT
9 HYDRAULIC LIFT UNIT
EF494T TM 06/2011 edition
188
Oil flow in lift operation
(1) Tank
(2) Strainer
(3) Filter
(4) Hydraulic pump
(5) Intake block
(6) Relief valve
(7) Control valve
(8) Load check valve
(9) Cylinder head (Check valve)
(10) Hydraulic cylinder
Circuit in the control valve
The unload valve is applied with the pilot pressure (a) and (b) at
an equal level. It is closed by means of the spring and the oil
pressure from the pump increases to cause the oil to go through
the throttle in the spool to the cylinder after opening the check
valve.
This is the process of a rapid pressure increase. The flow control
valve and mechanical check valve are both closed.
When the hydraulic lift rises, a feedback takes place to make the
spool return to the neutral position and the main spool throttle
makes part of oil flow through the tank after opening the flow
control valve. The remaining oil flows to the cylinder to eliminate a
shock at the upper dead point.
(A) Flow control valve
(B) Load check valve
(C) Mechanical check valve
(D) Tank
(E) Unload valve
(F) Main spool
Summary of Contents for EF-494T
Page 1: ...EF494T TM 06 2011 edition ...
Page 85: ...3 ENGINE 3 ENGINE EF494T TM 06 2011 edition 77 3 ENGINE ...
Page 88: ...3 ENGINE 3 ENGINE EF494T TM 06 2011 edition 80 B Return ...
Page 126: ...4 CLUTCH 4 CLUTCH EF494T TM 06 2011 edition 118 4 CLUTCH ...
Page 130: ...4 CLUTCH 4 CLUTCH EF494T TM 06 2011 edition 122 ...
Page 133: ...5 TRANSMISSION 5 TRANSMISSION EF494T TM 06 2011 edition 125 5 TRANMISSION ...
Page 167: ...7 FRONT AXLE 7 FRONT AXLE EF494T TM 06 2011 edition 159 7 FRONT AXLE ...
Page 169: ...7 FRONT AXLE 7 FRONT AXLE EF494T TM 06 2011 edition 161 7 2 CROSS SECTION VIEW ...
Page 176: ...8 POWER STEERING 8 POWER STEERING EF494T TM 06 2011 edition 168 8 POWER STEERING ...
Page 234: ...11 APPENDIXES 11 APPENDIXES EF494T TM 06 2011 edition 226 11 APPENDIXES ...
Page 235: ...11 APPENDIXES 11 APPENDIXES EF494T TM 06 2011 edition 227 11 1 HYDRAULIC CIRCUIT DIAGRAM ...
Page 236: ...228 11 2 ELECTRICAL CIRCUIT DIAGRAM 11 2 1 WIRING HARNESS ...
Page 238: ...230 11 2 3 ELECTRICAL WIRING DIAGRAM ...
Page 239: ......