Electro-Hydraulic Proportional Control for Use on a Rubber Tired Backhoe Loader

Within recent years, the use of electric remote controlled proportional valves in the mobile market has increased dramatically.

Manufacturers have realised that the use of electro-hydraulics opens up new design opportunities such as remote valve installations, precise fingertip control, electronic management of hydraulic machines, in fact an exciting new world.

Engineers have new options and possibilities to meet the customers demands for higher productivity, less power consumption and an ergonomically improved working environment.

Fig. 1 shows a representative selection of valves, joy stick controllers and electrical accessories for mobile equipment such as the backhoe described in this paper.

The electrical activation system is indicative of the direction development is taking. More and more electronics for control, regulation, monitoring and automating hydraulic systems are being used.

A description of a system where the mechanical control system has been replaced by an electro-hydraulic control system by Danfoss will follow.

The control system was built into a CASE 580K rubber tired backhoe now marketed as the CASE 580K Prestige.

The following subjects will be discussed:

The Hydraulic System

The Electrical System

The Operators Input and Comfort

Control of the Loader

Control of the Backhoe