wsm L503 Workshop Manual page 431

L3130 · L3430 · L3830 · L4630 · L5030, WSM
Draft Control Operation
When the draft control lever (6) is operated in the draft control operated range, the draft control lever shaft is
rotated, causing the draft cam (10) to move toward the roller (9) installed on the draft control link 2 (3).
(Reference)
• The sensitivity of the draft control can be adjusted by changing the gap between the draft cam (10) and the roller
(9) by the draft control lever (6).
Movement of the Link Under Increased Load (a)
1. When the traction load is increased, the torsion bar is twisted according to the load, the draft control rod (1) and
the draft cam (10) are pushed to come into contact with the roller (9).
2. Using the A portion as the fulcrum, the draft control link 2 (3) and the draft control link 1 (4) move to push the arm
1 (5).
3. At the same time, the arm 2 (11) is moved, the connected position control valve becomes the lift circuit, and the lift
arm goes up.
Movement of the Link Under Decreased Load (b)
1. When the lift arm goes up, the traction load is decreased, and the draft control rod (1) is returned.
2. At the same time, the arm 2 (11), arm 1 (5), and draft control link 1 (4) are returned by the return spring (8).
3. The position control valve becomes the down circuit, and the lift arm is lowered.
(Reference)
• The feedback rod (12) of the draft control is provided to maintain the position relation of the draft cam (10) and the
roller (9) to certain state regardless of the height of the lift arm.
8-M16
HYDRAULIC SYSTEM
(1) Draft Control Rod
(Connected to Top Link
Bracket)
(2) Draft Control Link 4
(3) Draft Control Link 2
(4) Draft Control Link 1
(5) Arm 1
(6) Draft Control Lever
(7) Position Control Lever
(8) Return Spring
(9) Roller
(10) Draft Cam
(11) Arm 2
(12) Feedback Rod (Connected
to Lift Arm)
(13) Draft Control Link 3
a : Lift
b : Down
W1016549
KiSC issued 02, 2007 A