At its Salzgitter site, Robert Bosch Elektronik GmbH produces engine control units and battery systems. Tractor-trailer trains carry materials from the warehouse to production and collect empty load carriers. Two EZS C40 tow tractors are also in use.
In the Robert Bosch production hall, the tractor-trailer trains distribute the components to multiple assembly areas along fixed routes. In doing so, each "train" covers around 60 kilometres per day. Great importance is therefore attributed to low consumption and virtually 100 percent availability, resulting in very short waiting times. Up to five entirely different trailer types require variable coupling solutions. The tractor-trailer trains also have to cope with narrow routes, in some cases just two metres wide along with very tight corners and constantly alternating work stages – get on, drive, get off, repeat.
"Thanks to the curveCONTROL function, the tow tractors brake automatically in corners without ever running off-track."
Using a range of different trailers, Bosch transports pallets and boxes with electronic components, electro-mechanical and mechanical parts, packing materials and finished products. On one of the EZS C40, we installed a special triple coupling allowing trailers with drawbars of different heights to be hitched to the tow tractor. The second tow tractor is equipped with a fixed coupling and a hydraulic connection for trailers that can raise and lower their cargo. Thanks to these variable coupling solutions, the tractor-trailer trains are extremely flexible.
Since our tow tractors are powered by 24 V drive motors with 3-phase AC technology, Bosch benefits from high acceleration and top speeds as well as a rated drawbar pull of 4000 kilogrammes. In addition, the 3-phase AC technology ensures significant energy savings, increased operating times and minimal maintenance costs. This is due to the optimum efficiency of this technology, along with the perfect co-ordination between the drive motor and traction controller as well as brake energy recovery.
The EZS C40 tow tractors handle the narrow paths, which in some cases are just two metres wide, and the tight corners with aplomb: With a width of just 810 millimetres, they are actually narrower than some trailers and thus easily meet the maximum permitted dimension. Operator safety and comfort are facilitated by curveCONTROL travel speed reduction, which takes effect in corners, the speedCONTROL impulse control system and the jetPILOT steering wheel. On straight routes, the EZS C40 tow tractors maintain speed set by the operator via the travel switch, even on uphill and downhill gradients.
Despite the long travel times, the tow tractors are not fitted with seats. Operators get on and off the machines 70 to 80 times per shift, something which is much easier from a standing position. Instead of the optional folding seat, we have equipped the tow tractors with a standing aid in the form of a supporting backrest. The lack of a seat also means that the operator has more freedom of movement on the stand-on platform.
Wolfgang Thürmer, logistics specialist at the Robert Bosch site in Salzgitter, is particularly pleased with the facility for unhitching the trailers using the push button control integrated on either side of the backrest. He also praises the electric steering and the jetPILOT of the EZS C40, not least for its direct response and resulting steering comfort. Production foreman Peter Tenscher highlights the excellent support received from our customer service department. André Hätscher, group leader for automotive electronics/production-related logistics is delighted with the virtually 100 percent availability of the EZS C40 and states that the tow tractors represent the perfect solution for use in narrow aisles with frequently alternating work stages.