Abstract: In a construction machine according to the present invention wherein there is made an engine speed sensing control to control a pump horsepower in accordance with an engine speed of an engine. there is performed, in a low temperature condition with hydraulic oil temperature not reaching a preset temperature, a low temperature horsepower control involving setting the pump horsepower lower than at room temperature which is not lower than the preset temperature to lighten a burden on the engine. With this control, it is possible to prevent the occurrence of engine overtorque and hunting at a low temperature.

Abstract: The present invention discloses a traveling control device, including a crawler type right and left traveling body; a right and a left hydraulic motor for operating the right and left traveling body using each hydraulic pump as a hydraulic source; an operating means for outputting an operation command to the right and the left hydraulic motor; and a pump pressure control means for controlling pump pressure to be supplied to the right and the left hydraulic motor according to a control input of the operating means, wherein the pump pressure control means controls the pump pressure based on different pump pressure properties for single traveling in which only one of hydraulic motors is operated, and for double traveling in which both of hydraulic motors are simultaneously operated. Therefore, by designing different properties of the pump pressure to be applied to the single traveling and the double traveling, the manipulation ability of the traveling control device is greatly improved.