Abstract: A control apparatus for a hydraulic excavator is capable of carrying out precise operations according to various kinds of classifications of works without requiring switching operations by an operator and management according to work records. The apparatus includes a classification of work discriminating section for recognizing a classification of work being carried out by the hydraulic excavator on the basis of data detected by sensors for detecting an operating amount of a lever for a boom and the like; sections for setting an operating mode of hydraulic pumps absorbing horse power and the like, according to the classification of work recognized; a hydraulic pump control section for controlling the hydraulic pumps according to the set operating mode; and an auto acceleration control section for making effective or invalid the auto acceleration control for controlling speed of an engine to a low speed when work stops.

Abstract: A cooling control system by which an internal combustion engine is prevented from overheating, and a fail-safe function exerts its effect. A butterfly valve 34b for regulating the flow of cooling water is rotated by a motor 31, a clutch mechanism 32, and a speed reduction mechanism 33, thereby cooling the engine to be at the most suitable temperature for driving. The aforesaid butterfly valve 34b is given momentum in a direction to open the valve 34b by a return spring 34e. For example, an angle sensor 34g for detecting the rotational angle of the butterfly valve 34b is included. In a computing unit, when it is determined that an abnormality occurs from the relationship between the data from an encode 34g and the temperature of the cooling water, the clutch mechanism 32 is released, and the butterfly valve 34b is automatically opened. Accordingly the engine is prevented form overheating.