| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a working machine capable of controlling an engine rotation speed by judging the lowering state of a working device without attaching a pressure sensor to a vertically moving cylinder of the working device. <P>SOLUTION: The working device is constituted to prevent automatically lowering an engine target rotation speed which is setup at a dial value of an accelerator dial when performing a boom lowering operation during excavation, and constitutes an algorithm with only a minimum of sensors of a pump pressure sensor 43 for detecting the pump pressure and an operation valve sensor 44 for detecting an amount of lowering a boom lever. A controller estimates an amount of lowering the working device by integrating the lowering speed of the working device which is obtained from the amount of lowering operation detected by the operation valve sensor 44, controls by judging that the working device is in the lowering state in the air and lowers the engine target rotation speed less than the initial setup rotation speed when the lowering amount is smaller than the lowering amount of setup value, and sets back the engine target rotation speed to the initial rotation speed setup value when the lowering amount is bigger than the lowering amount of setup value. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
