3-13
3
FUNCTION
PROPORTIONAL CONTROL SOLENOID VALVE
PROPORTIONAL CONTROL SOLENOID VALVE
3KAD01Z
1
2
4
S=A1-B1
S
Paxs
Paxs
Fk
Fs
Fks
B1 A1
A
P
T
Fs
Fks
Fk
3KAD02Z
A
P
T
1
5
3KAD03Z
A
P
T
1
6
This valve controls the secondary pressure by using the
built-in proportional pressure reducing valve.
The secondary pressure generated corresponds to the
changes in current, because the force used to generate the
secondary pressure is applied to the solenoid according to
the current passing through the coil.
When a current flows in the solenoid, a thrust force propor-
tional to the current is generated and it pushes the spool
(1) so that the oil supplied from the port P is directed to the
secondary pressure side port A to increase the pressure
Pa in the port A.
This pressure Pa works on the differential area S between
the cross sections A1 and B1 of the spool (1), and the spool
(1) is pushed to the solenoid side by the oil pressure Pa x S.
The spool (1) stops at the position where the sum of the oil
pressure Pa x S and the force Fk exerted by the springs (2)
is balanced with the thrust force Fs generated by the sole-
noid. The weight Fks of the spring (4) for fine adjustment of
the secondary pressure works in the direction (left) to assist
the thrust force from the solenoid.
When the thrust force becomes larger than the set value,
the spool (1) is moved to the left, connecting the port P
(supply side) and the port A (secondary side) through the
notch (5).
When the thrust force becomes smaller than the set value,
the spool (1) is moved to the right, connecting the port A
(secondary side) and the port T (tank side) through the
notch (6).
Therefore, the opening areas of the supply side notch (5)
and discharge side notch (6) are controlled by the move-
ment of the spool (1), and secondary (pilot) pressure cor-
responding to the thrust force generated by the solenoid
can be provided.
Summary of Contents for TB 250
Page 1: ......
Page 3: ...1 1 SAFETY 1 Safety alert symbol 1 2 Safety precautions 1 3 Cautions when working 1 9...
Page 36: ...2 24 2 TIGHTENING TORQUE SERVICE DATA...
Page 38: ...2 26 2 HYDRAULIC CIRCUIT DIAGRAM SERVICE DATA Equipped with options 2 2...
Page 39: ...2 27 2 HYDRAULIC CIRCUIT DIAGRAM SERVICE DATA Equipped with angle blade and blade oat 1 2...
Page 40: ...2 28 2 HYDRAULIC CIRCUIT DIAGRAM SERVICE DATA Equipped with angle blade and blade oat 2 2...
Page 41: ...2 29 2 HYDRAULIC CIRCUIT DIAGRAM SERVICE DATA Equipped with high ow option 1 2...
Page 42: ...2 30 2 HYDRAULIC CIRCUIT DIAGRAM SERVICE DATA Equipped with high ow option 2 2...
Page 49: ......
Page 59: ...2 46 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 60: ...2 47 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 61: ...2 48 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 62: ...2 49 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 63: ...2 50 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 64: ...2 51 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 65: ...2 52 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 66: ...2 53 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 67: ...2 54 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 68: ...2 55 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 69: ...2 56 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 70: ...2 57 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
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Page 73: ...2 60 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA NAME STANDARD NO...
Page 74: ...2 61 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 75: ...2 62 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 76: ...2 63 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 77: ...2 64 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 78: ...2 65 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 79: ...2 66 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 80: ...2 67 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 81: ...2 68 2 WIRE HARNESS WIRING DIAGRAM SERVICE DATA...
Page 92: ...3 11 3 CONTROL VALVE FUNCTION...
Page 108: ...4 3 4 SERVICE STANDARDS DISASSEMBLY AND ASSEMBLY Clearance for pin and bushing...
Page 352: ...ENGINE 6 Machine model Mounted engine TB250 4TNV88...