| A front-end loader for agricultural purposes is the most commonly used implement for agri-tractors in Korea. As it is operated to raise, lower and carry various objects in a farming field, it introduces a large amount of stress to a tractor, causing vibrations and often lead to a mechanical breakdown. These high stresses are observed at the starting and ending points of operation, that is, the points at which the highest acceleration and deceleration occur. To reduce the sudden change of the speed, soft-start & end operation were tested with an electrohydraulic directional valve, which has a built-in ramp time spool control function. This valve was controlled by SAE-J1939 associated messages via CANBUS. This shock-absorbing system contains three ECUs... |
