 A power assisted servo control valve reduces the effort required to lift a full load by 66% Doosan nominated for more Archies
November 14th 2006 Doosan has been shortlisted for another two FLTA Awards. This time for its new D160-5 16 tonne machine, in the Ergonomics category, as well as an operator sensing system in the safety category.
In the ergonomics category, Doosan researchers discovered that the traditional mechanical type hydraulic control valve found in most big forklift trucks, caused operators undue fatigue in their arm and shoulder from repeated operation. The latest fingertip controllers were also considered too delicate for a truck typically found travelling over uneven terrain with considerable loads.
The answer to the problem was found with a power assisted servo control valve, reducing the amount of effort required to lift a full load from 2kgf to just 0.3kgf - a reduction of 66% - and allowing extremely precise control into the bargain.
The valve system is supported by hydraulic power of 30 bar pressure taken from the normal 210 bar hydraulic operating system. With the additional hydraulic support, the system requires less stroke and less force to operate.
Meanwhile, the safety nomination highlights a simple detection system to prevent mis-operation. To prevent motion of the truck without an operator in the seated position, the OSS will place transmission in neutral within approximately three seconds of the operator leaving the seat.
Additionally, an alarm will sound if the operator does not apply the parking brake upon exiting the machine.
When the operator returns to the seated position, the operator must first place the directional lever to the neutral position, and then select the desired direction.
A double acting parking lever gives added reassurance via a warning buzzer, if the operator leaves without engaging the brake. Doosan Daewoo's Operator Sensing System (OSS) is standard on all Year 2006 models.
Voting takes place in December, with the lucky winners receiving their awards in February. More articles from Doosan Infracore Co. Ltd: | 
