Buhler 2180 - Manual (Page 132)

SECTION 2 - OPERATION
2-86
THREE-POINT HITCH CONTROLS
INTRODUCTION
The electro-hydraulic three-point hitch control
system employs electronic switches and a micro-
computer to control the hydraulic system, which
raises and lowers the 3-point linkage.
MODES OF OPERATION
The electro-hydraulic three-point hitch system offers
three modes of operation, position, draft, and float.
Position Control provides accurate and sensitive
control of implements that operate at a fixed position.
Once set, position control will maintain the selected
implement height. When operating in position control
the tractor and implement become, in effect, a rigid
unit. Irregularities in the soil surface will cause the
implement to rise and fall according to movement of
the tractor.
Draft Control provides for a uniform load to be
maintained on the tractor by automatically adjusting
the working height/depth of soil engaging
implements.
The changes in draft loading are sensed electronical-
ly through special load sensing pins used to connect
the lower links to the rear axle housing. These pins
send and electronic signal to the computer which, in
turn, signals the hydraulic system to respond by
raising or lowering the implement to maintain the
requested draft load.
Float Control provides a means of operating
implements that operate with the contour of the soil
surface, including implements that operate with
gauge wheels or other devices that limit operating
depth. Float control also allows for lateral movement
of the implement on uneven surfaces.
The set-up and operation of each mode of operation
is described later in this section.
NOTE: The electro-hydraulic three point hitch is a
separate system from the electro-hydraulic remote
valves. The engagement switch for the electro-
hydraulic remote valves that can be used as a
isolator switch has no operational control over the
electro-hydraulic three point hitch. Depressing the
engagement switch will have no effect on stopping
the three point hitch in an emergency situation.