Automatic Tracking Steering Drawbar

Machines with automatic tracking drawbar control are tracking accurately if the drawbar pivot is exactly halfway between the tractor rear axle and the sprayer axle. To achieve this, the distance (A) between the pivot of the drawbar and the rear axle of the tractor must be 243.9 cm with an allowable tolerance of + or - 50 mm. Refer also to "Steering Drawbar Pivot" in the section "Preparing the Tractor".

WZ00085,000039C -19-31AUG05-1/3

The drawbar is electro-hydraulically controlled by means of two sensors (A) on the front side of the drawbar. These sensors measure the position of drawbar in relation to the tractor.

If the drawbar is not tracking straight behind the tractor, the sensors measure this and pass on the information to an electro-hydraulic control valve (B) on the machine.

The electro-hydraulic control valve sends oil to the control cylinder(s) (C). The drawbar is then adjusted so that the wheels of the machine run exactly in the tracks of the tractor. Refer also to "Adjusting The Automatic Tracking System With Steering Drawbar" in the section "Adjustments".

A-Sensors
B-Electro-hydraulic control valve
C-Steering cylinder(s)

WZ00085,000039C -19-31AUG05-2/3

As the system can be switched off from the cab (manually operated position), the machine is just as stable as a fixed machine during transport and during spraying. Using manual control, the machine can also be manoeuvred in field corners or corrected when working on slopes.

The tracking system is fitted with an automatic centering device with sensors (A). When the controls are switched off after turning at the field headland, for smooth running of the machine during spraying, one press of the switch brings the drawbar automatically back to the central position, so that the machine runs straight behind the tractor, thus preventing damage to crops and excessive boom yawing.

A well-fitting draw pin is essential for the proper functioning of the automatic steering system.

A-Sensor

WZ00085,000039C -19-31AUG05-3/3