The new Jungheinrich IC engine truck with hydrostatic drive has been rolling off the assembly line in Moosburg since December 2007. The truck type VFG 425-435s is able to transport loads up to 3,500 kg, stack up to a lift height of 7.5 m and has hydrostatic drive technology "made in Germany": Centre pieces of the new trucks are Volkswagen motors applied in both Diesel (DFG) and LPG (TFG) versions. Variable displacement pumps and wheel motors are supplied by Bosch Rexroth and the system is controlled completely by Jungheinrich-developed software.
"Hydrostatic travel characteristics stand for excellent travel comfort and high throughput efficiency, particularly in intensive applications with a lot of changes in direction," explained Dr. Tobias Harzer, Head of Product Management and Product Marketing for Counterbalance Trucks at Jungheinrich Moosburg GmbH. This in practical terms means fast and direct acceleration and fast but smooth and sleek change of direction. "The truck is cut out for so-called reversing operations, for example during lorry loading and offloading," Harzer continued.
The number of rotations is automatically increased during hydraulic working processes. Travel and hydraulic processes are implemented directly, precisely and effortlessly due to hydrostatic drive technology. By pressing a button, the operator has a choice of five predefined working programs from energy saving mode to maximum throughput for flexible truck adjustment to his application.
The hydrostatic drive technology has only a few mechanical components and is thus service-friendly and low-maintenance. By utilising Volkswagen motors, several advantages from the automobile industry now make their entrance in the IC engine driven fork lift trucks from Jungheinrich. They are very quiet and have considerably lower energy consumption and therefore very low emission values.
Safety I: Jungheinrich hydrostat with high dynamic stability
The Jungheinrich VFG 425-435s with hydrostatic drive provides a high degree of safety in day-to-day operation. Due to the special design of the counterweight and the high mounted safety steering axle, the truck has a low centre of gravity and thus excellent stability. No additional electronic stability program is therefore required. This principle has already been used in IC engine driven trucks developed by Jungheinrich since 2004.
Other safety aspects are quite "obvious" on the Jungheinrich VFG 425-435s. A special design of the desk wall provides the operator with excellent visibility to-wards the front and the fork tips. Visibility to the rear was also considerably im-proved due to the low top edge of the counterweight. During the depositing and retrieval of pallets, the operator also has virtually unobstructed visibility to the top due to a strut-free safety glass window.
Safety II: New safety packages for more protection against operating errors
Different new safety packages in addition to construction-dependent safety are optionally available for the Jungheinrich hydrostat. For example, Access Control is a system that releases the stacker only after a certain sequence of safety mechanisms (closed seat switch, safety belt). Drive Control is based on the active safety system Curve Control that has been successfully installed in Jungheinrich electric trucks for approximately eight years. Here, the travel speed on corners is reduced dependent on the steering angle. Speed from a defined lift height is also simultaneously reduced.
In the safety package Lift Control, the tilt speed is also reduced from a defined lift height, the tilt angle is shown and, if required, the sideshift is moved to a pre-programmed central position. Also new on Jungheinrich IC engine trucks is an expanded safety locking system combined with seat occupation recognition. It provides more protection against operational errors. For example, no hydraulic function is activated if the seat is unoccupied.
Apart from the optional safety packages, the Jungheinrich VFG 425-435s also has a number of other safety packages already tried and tested in other ranges. These include a self-activating parking brake preventing roll-back on ramps or inclines and the entry step visible from above for effortless operator entry and exit.
Ergonomics: Travel comfort and high throughput efficiency
The generous and ergonomic design of the Jungheinrich VFG 425-435s work-place does not only provide comfort and relaxed travelling but also high through-put. "If the operator not only feels safe but also good on our trucks, this reflects one to one on the efficiency of the truck," explains Tobias Harzer. With or without cab, the truck is considerably quieter than converter trucks in the same class. Human vibrations are reduced to a minimum due to double decoupling of drive unit and operator workplace module from the chassis. "Here we achieve values equivalent to the lowest values of our electric stackers," Harzer continues.
The seat-bound operating elements in a co-vibrating, two-stage adjustable arm-rest are also new. The operator also has the choice of selecting either the solo pilot or the multi pilot – both with integrated travel direction switch. An electrically activated parking brake, a start button as on newer motor cars and a duo-adjustable, slim steering column with memory function providing even more leg-room and freedom of movement round off the innovations on the VFG 425-435s from Jungheinrich.