excavator

Abstract

The present invention provides an excavator capable of controlling a hydraulic pump with higher responsiveness. The excavator according to the embodiment of the present invention includes: an arm cylinder (8); a hydraulic pump (14) that supplies operating oil to the arm cylinder (8); a model predictive control unit (34) that The expansion and contraction speed (v), pump discharge pressure (Pd) and displacement (Vd) of the hydraulic pump (14), the displacement command value is derived by predicting the pump discharge pressure (Pd) and displacement (Vd) after a predetermined time (Vtc); and a controller (30) controlling the hydraulic pump (14). A controller (30) controls a hydraulic pump (14) using a displacement command value (Vtc) derived by a model predictive control unit (34).

Description

Technical field[0001]The present application advocates priority to Japanese Patent Application No. 2015-049793, issued by March 12, 2015 and Japanese Patent Application No. 2015-051368, applying for March 13, 2015. All of these Japanese applications are used in this specification by reference assistance.[0002]The present invention relates to an excavator having a hydraulic drive.Background technique[0003]A construction machine is known to prevent the drama of fuel injection amount due to the dramatic reduction of the engine speed when the discharge pressure of the hydraulic pump has increased dramatically (see Patent Document 1).[0004]The construction machine is controlled by horsepower so that the pump absorption torque of the hydraulic pump does not exceed the engine output torque even if the discharge pressure of the hydraulic pump is changed. Specifically, in the case where the discharge pressure of the hydraulic pump is increased, the amount of discharge is lowered such that th...

AI Technical Summary

Problems solved by technology

[0006] However, in the above-mentioned construction machines, the point that the discharge volume of the hydraulic pump is lowered after detecting a sudden increase in the discharge pressure of the hydraulic pump has not changed, and the time required for the discharge volume to be lowered until the discharge pressure is actually lowered, that is, hydraulic pressure. Influence of pump response delay time

Therefore, depending on the setting of the reduced predetermined torque (low torque), the pump absorption torque of the hydraulic pump may be increased beyond the engine output torque, or the pump absorption torque may be excessively reduced.

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