Manitowoc 14000 Service Maintenance Manual

Reference Only
INTRODUCTION 14000 SERVICE MANUAL
1-64
Published 09-05-14, Control # 226-02
Carbody Jacking Cylinder Lower
See Figure 1-35.
Move jacking levers forward to lower position to lower
jacking cylinders. This shifts selected lower accessory valve
to block charge pressure to carbody pressure sender.
System pressure bleeds out through orifice and system
pressure drops, sending an input signal to the node 1
controller.
Node 4 controller sends a variable 28 output voltage to drum
1 pump EDC that tilts pump swashplate to stroke pump in
low-pressure side direction. Hydraulic fluid flows through
upper accessory system valve to lower accessory valve
where system pressure is approximately 3,100 psi (215 bar).
Hydraulic fluid exits valve section of lower accessory valve
and flows through restraining section of flow control valve.
Restraining section controls rate of speed for cylinders to
retract by limiting the velocity of fluid before passing through
free-flow check valve section of counterbalance valves.
Hydraulic fluid then flows into rod end of jacking cylinders.
Hydraulic pressure entrapped by cylinder counterbalance
valves at piston end of jacking cylinder supports the weight
and gravitational force of carbody. Node 1 controller monitors
accessory system pressure sender to control jacking
cylinder speed rate.
Hydraulic fluid exhausting from piston end of jacking
cylinders is blocked by free-flow check valve section of
counterbalance valve and flows through the flow restraining
section that has a relief setting of 3,500 psi (240 bar).
Counterbalance valve acts as a deceleration control and
functions with a 3:1 pilot ratio of relief pressure. This permits
valves to open when the pressure in piston end of cylinders
is approximately 1175 psi (81 bar). Restraining section of
counterbalance valves open that controls fluid out of jacking
cylinders to lower accessory valve. Hydraulic fluid leaving
lower accessory valve is returned to tank.
Move control levers back to neutral position when desired
height is reached. When system pressure beyond lower
accessory valve increases, an input signal to the node 1
controller. Node 4 controller sends a zero output voltage to
drum 1 pump that returns pump swashplate to neutral and
de-strokes the pump.

Manitowoc 14000 Specifications

General

Brand	Manitowoc
Model	14000
Category	Construction Equipment
Language	English