Controlling device used to save fuel for construction machinery

Abstract

A control apparatus for fuel savings for a construction machine is disclosed, which can set engine and pump input torques to be in a high efficiency section at an equal level of the final output horsepower of a pump if a fuel saving mode is selected through an installed fuel saving mode switch, and thus can obtain a fuel saving effect for an equal amount of work.

1 . A control apparatus for fuel savings for a construction machine having an engine and a variable displacement hydraulic pump connected to and driven by the engine, the control apparatus comprising:
 a mode selection switch selecting any one setting step among a plurality of setting steps for a speed of the engine and a maximum input torque of the hydraulic pump according to a user's key operation;   a fuel saving mode selection switch selecting a fuel saving mode according to the user's key operation;   a first data storage means for storing first data that is composed of the engine speed that becomes a standard when the fuel saving mode is not selected and the maximum input torque value of the hydraulic pump for each of the plurality of setting steps;   a second data storage means for storing second data that is composed of an engine speed setting value that is lower than the engine speed of the first data and the maximum input torque value of the hydraulic pump that is higher than the maximum input torque value of the hydraulic pump of the first data; and   a controller for fuel savings controlling the engine and the hydraulic pump on the basis of the second data composed of the engine speed and the maximum input torque value of the hydraulic pump in the setting step that is selected by the mode selection switch when the fuel saving mode is selected through the fuel saving mode selection switch, and controlling the engine and the hydraulic pump on the basis of the first data in the setting step that is selected by the mode selection switch when the fuel saving mode is not selected through the fuel saving mode selection switch.   
     
     
         2 . The control apparatus for fuel savings according to  claim 1 , wherein the controller for fuel savings comprises:
 a first control means for controlling the engine and the hydraulic pump on the basis of the second data composed of the engine speed and the maximum input torque value of the hydraulic pump in the setting step that is selected by the mode selection switch if a fuel saving mode selection signal is input from the fuel saving mode selection switch; and   a second control means for controlling the engine and the hydraulic pump on the basis of the first data composed of the engine speed and the maximum input torque value of the hydraulic pump in the setting step that is selected by the mode selection switch if a fuel saving mode non-selection signal is input from the fuel saving mode selection switch.