jcb JS70 Service Manual

3 - 10
Swing Operation (0% Swing Brake)
Before swing operation the swing mechanical brake is
maintained at 50% (operations other than swing
operation). In performing swing operation, the
mechanical brake is released and normal swing
movement is possible.
Pressurised oil from port A1 (front pump) enters port 5P
of the control valve. Due to the right swing operation of
the remote control valve, the pilot pressurised oil flows
to port 5Pb1 of the control valve and switches the swing
spool. The pressurised oil that entered port 5P of the
control valve flows to port A of the swing motor and a
right swing is performed.
In order to release the integral 50% swing mechanical
brake in the swing motor, the pressure switch (in the ON
position) detects the pilot pressure of the swing signal.
The electrical signal is sent to the switch panel (right)
which de-energises the swing brake solenoid valve in
the multiple valve.
This allows the 40 bar pressure entering the multiple
valve from the pilot pump to flow through the reducing
valve without any reduction in pressure. The mechanical
brake in the swing motor is fully released making swing
operation possible.
Section E Hydraulics
9803/6020
Section E
3 - 10
Issue 1
Schematics
A
Pressure Line
B
Return Line
C
Pilot line
D
Electric Signal
E
Control Valve
F
Swing Motor
G
Hydraulic Pump
H
Reducing Valve
J
Swing Brake Solenoid
K
Multiple Valve
L
From Pilot Pump
M
Swing Panel (Right)
N
Pressure Switch

jcb JS70 Specifications

General

Brand	jcb
Model	JS70
Category	Excavators
Language	English