| 摘要 |
PURPOSE:To prevent an overload from acting on an engine in the case of generating abnormality in an engine speed detecting means. CONSTITUTION:A target speed Ns of an engine 40 is set by an engine speed setting switch 60 to respectively detect the actual speed Nr of the engine 40 by an engine speed sensor 90 and a delivery oil pressure P of an oil hydraulic pump 10 by a pressure sensor 100. In a pump control part 80, when the engine speed sensor 90 is normal, absorbing torque of the oil hydraulic pump 10 is set based on a deviation Ns-Nr between the target speed Ns and the actual speed Nr and the delivery oil pressure P. On the other hand, in the case of detecting abnormality of the engine speed sensor 90 in an abnormality detecting part 110, the deviation Ns-Nr is replaced with a difference between a preset rotational speed and the target speed Ns. |
