Manitowoc MLC165-1 Service Maintenance Manual

Reference Only
Manitowoc Published 05-26-17, Control # 238-02 6-3
MLC165-1 SERVICE/MAINTENANCE MANUAL SWING SYSTEM
6
6
Swing Handle Command
The swing control system receives operator commands via a
proportional hydraulic control handle. Left or right control
handle movement ports pilot pressure to the corresponding
pressure transducer. The pressure transducer sends a
proportional 1Vdc to 3Vdc output signal to Node 3, which
reads it as a command signal of swing speed.
Swing Pump Control
The swing pump is driven by the engine. Pump flow is both
directional and variable, determined by position and stroke of
a proportional solenoid valve in the electronic displacement
control (EDC). Node 4 sends a 1.6 to 8.8Vdc PWM output
signal to the EDC, with the current control range starting at
200mA and ending at 600mA. Node 4 ramps up the PWM
duty cycle to meet the speed commanded at the control
handle. As current increases, more fluid is ported to the
swashplate servo pistons, increasing the swashplate angle.
As the swashplate angle increases, so does the piston
stroke within the pump, increasing pump output volume.
Swinging Left
When swinging left, node 4 sends a PWM signal to
proportional solenoid B in the swing pump EDC, energizing
it. The pump flows fluid port B to motor port B, and moving
the operator cab to the left. Return fluid from motor port A
flows to pump port A, completing the closed-loop circuit.
Swinging Right
When swinging right, node 4 sends a PWM signal to
proportional solenoid A in the swing pump EDC, energizing
it. The pump flows fluid port A to motor port A, and moving
the operator cab to the right. Return fluid from motor port B
flows to pump port B, completing the closed-loop circuit.
Coasting
When the swing control handle is moved back to the neutral
position, Node 4 ramps down the PWM signal to the
energized A or B EDC solenoid, allowing the springs to
center the spool, moving the pump swashplate to center
position, and ceasing swing drive.
The rotating bed is free to coast via an orifice in parallel with
the motor and pump if the swing control handle is in neutral
position and the swing brake is released.
Swing System Pressure Feedback
Pressure transducers at the A and B sides of the motor
provide feedback for the control algorithm.
Swing Alarms
The swing alarms are activated anytime the EDC solenoid
valve is being driven.

Manitowoc MLC165-1 Specifications

General

Brand	Manitowoc
Model	MLC165-1
Category	Construction Equipment
Language	English