Explanation of Hydraulic Circuit and Operations (standard model) Swing Circuit Swing brake circuit
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As an example, this section explains the brake circuit operation after the end of a right swing operation. When the remote control valve is returned to neutral from a right swing operation, the pilot pressure oil is cut off and the control valve swing spool returns to neutral. The pressurized oil fed to the swing motor A port from the control valve A3 port is cut. At the same time, the destination location is eliminated for the pressurized oil flowing from the swing motor B port to the control valve B3 port, so the pressure rises to the swing motor relief valve set pressure. The pressure generated here becomes a brake force and stops the motor. When the swing is stopped, the swing motor continues to rotate for a while due to inertial force.In order to make up the shortfall in the oil volume, oil is supplied from the make-up line connected to the swing motor M port from the control valve T3 port to open the make-up check valve and oil is suctioned in to prevent cavitation.
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Pressure line Tank line Pilot pressure line Pilot tank line Electric line
1
Swing motor
9
2
Cushion valve
10
Lever lock Swing brake
3
Right swing
11
5 stack solenoid valve
4
Left swing
12
Console lever lock switch
5
Swing pilot pressure sensor
13
Computer A
6
Remote control valve (arm, swing)
14
Control valve
7
Hydraulic pump
15
Oil cooler
8
Check valve
16
Upper pilot pressure sensor
52 13
