| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent engine stall and improve a travelling speed during work and facilitate the restoration of an engine speed when greatly dropping, in a work machine equipped with a HST for driving a travel device. <P>SOLUTION: The work machine includes a pressure control valve 34 for controlling a travelling primary side pressure and a control device CU for controlling the pressure control valve 34. The control device CU controls the pressure control valve 34 to create a drop characteristic line Z showing a relationship between an actual engine speed and the travelling primary side pressure when a predetermined or greater load works on an engine 29. The drop characteristic line Z is bent on its way, and has a first characteristic line part E1 which is set so that the travelling primary side pressure rapidly drops as the actual engine speed is down from a target engine speed, and a second characteristic line part E2 which is set so that the travelling primary side pressure more gently drops than that in the first characteristic line part E1 as the actual engine speed is down when the engine speed is further down. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
