31 - 6
Operation (cont’d)
Individual Operation
1. Travel Spool Switch (Refer to Fig. 1, 2, 3).
When port 4Pa1(4Pb1) is pressurised and the travel right
spool is selected, the neutral passage (a) is closed with the
downward flow cut off.
The oil delivered from port 4P enters through passage (c)
from the neutral passage (a) and flows out of motor port 4A1
(4B1). The return oil from the ram port passes through 4B1
(4A1), through the spool neck and returns back to the tank.
When port 5Pa5 (5Pb5) is pressurised and the travel left
spool is selected, the oil is delivered from port 5P to the
shuttle neck. The flow passes through the parallel passage
(B), passage (C) to the motor port 5A5 (5B5). The return oil
flows into 5B5 (5A5) and returns back to the tank.
Part of the flow of oil from 5P passes through the restrictor
(29) into the passage (C) and lifts the poppet (9) to port 5A5
(5B5).
Section E
Hydraulics
9803/6020
Section E
31 - 6
Issue 1
Control Valve
289780
14
Fig. 3
A
B
F
G
C
D
E
A
Travel (Left)
B
Travel (Right)
C
To Bucket Section
D
5Pa5 (Neutral) (5Pa5 Pressurisation)
E
4Pa1 (Neutral) 4Pa1 Pressurisation)
F
5-Spool Parallel Passage
G
4-Spool Parallel Passage
Summary of Contents for JS70
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