Following the work

Following the work
Marginal Column

Photos: Dieci S.r.l.

Content

November 2014

 

The new 2+1 drive concept developed by Rexroth has made the new telescopic handlers built by Dieci S.r.l. more than just economical. This all-rounder has even crossed the Alps.

 

Telescopic handlers are very popular among farmers. These machines push and pull, help when mucking out the stalls, raise heavy loads to great heights, move things about, and can even plow. In a few words: These compact and nimble all-purpose units are suitable for many jobs. Dieci S.r.l. is truly a pioneer in this field. In 1983 this Italian company was the first in Europe to market a telescopic handler. In the meantime this manufacturer, located in the community of Montecchio Emilia, southeast of the city of Parma, is among the world’s leaders in the field. “In mid-2012 Dieci approached us with a request for a fully harmonized drive system, comprising the controls, drive and gearing. Nor was the subject of safety to be forgotten,” recalls Roland Friedl. Active in sales and telehandler industry management for Bosch Rexroth in Elchingen, he played a pivotal role in the development of the Agri Plus 40.7 VS Evo2. Farmers now use this machine, incorporating state-of-the-art technology, to work their fields all across Europe. The machine is fitted with an efficient travel drive, makes possible smooth gear shifting without interrupting the power flow, is miserly with fuel, and satisfies the latest exhaust standards.

2+1 = Thrifty

This is primarily due to the electronically controlled 2+1 hydrostatic travel drive built by Rexroth, used for the first time in a telescopic handler of this performance class. The principle behind this drive concept is: A diesel engine, developing 96 kilowatts, powers two hydraulic motors. The smaller is a fixed-displacement motor, the other a variable motor. Acting in conjunction with a gearbox, they put the telehandler into motion. In this way, the operator can shift the moving implement from low gear to second gear, the so-called travel gear, either automatically or manually. “Anyone who steps on the clutch in a car disconnects the flow of power from the engine to the gearbox. Our design eliminates this, since there is no interruption in the traction force,” Friedl noted. When Agri Plus, pulling a trailer weighing tons, climbs a hill, it does not stop when shifting back into first gear. In spite of the improved performance, Dieci indicates that the new vehicle uses 20 percent less fuel.

Telescopic loaders are very popular among farmers because they are highly maneuverable and can be used for many purposes. Photos: Dieci S.r.l.

 

Clever and safe

This saving is achieved because the two hydraulic motors are intelligently matched one with another. If the Agri Plus 40.7 VS Evo2 needs full power in the working cycle, then both are put to work. When moving at high speeds in the travel gear and if the operator calls for only minimal power, then the variable motor is disconnected; the smaller motor is adequate. If the vehicle once again requires greater power, then the variable motor is re-engaged.

Friedl mentions an additional advantage: “In this way we were able to improve the efficiency level significantly.” There is also an eco-mode, which the operator can activate by push-button control whenever power needs are low. This then reduces the speed of the diesel engine without having any effect on travel speed. To achieve this, the travel drive control unit communicates with the engine controls via a CAN bus. With this fuel-saving drive concept, Rexroth makes an important contribution to the telescopic handler’s achieving compliance with the “TIER 4 final” emission standard.

Trend-setting safety

“One further important point during development was functional safety, as prescribed by European Standard ISO 13849,” Friedl reports. The goal here is for the machine’s controls to operate reliably, never endangering anybody’s safety. To complete the design of the telescopic handler, it was necessary to work out a new safety concept so as to meet the requirements.

Strong valve

A telescopic handler can use its extending boom to raise loads to great heights. A farmer might use this function, for instance, to stack bales of straw in the barn’s hayloft. The Agri Plus 40.7 VS Evo2 can raise as much as four tons to a height of seven meters. The Control Plus Valve, built by Rexroth, minimizes energy use. The operator manipulates a hydraulic joystick to control the working hydraulics on the boom. The valve makes it possible to lower the load using no energy beyond the force of gravity. In addition, the control pressure required for the descent is minor. This makes for fuel savings. What’s more, the drive can position the loads far more accurately since the precision control feature makes for smooth and uniform motion.

The Agri Plus 40.7 VS Evo2, made by Dieci, also makes it possible to change gears without interrupting the traction. Photos: Dieci S.r.l.

 

Used in many ways

“All in all, we have made controlling the machine as simple as possible for the operator. He can concentrate on his work and need not worry about shifting gears,” is how Friedl explains the benefits. The advantage of the hydrostatic travel drive by Rexroth is that it can be modified, without great effort, for other power classes, by using either more or less powerful hydraulic motors or other transmissions. Available is not only the 2+1 travel drive, but also 1+0, 1+1 and 2+3 configurations. These solutions are suitable not just for telescopic handlers, but for excavators, forklift trucks, wheel loaders and harvesting machinery, as well.

Journey across the Alps

Whenever farmers share a telescopic handler, roadworthiness in an important criterion since the machine will have to be shuttled between the fields. The employees at a Czech dealership showed how suitable the Agri Plus 40.7 VS Evo2 is for road use and even for long journeys. In March of this year they moved a vehicle, weighing almost five tons, over a distance of 878 kilometers between the Italian headquarters and the Czech Republic for charity reasons. Moving at a maximum speed of 40 kilometers per hour, they covered this distance in less than 37 hours