METHOD AND DEVICE FOR CONTROLLING PUMP TORQUE FOR HYDRAULIC CONSTRUCTION MACHINE

Title:

METHOD AND DEVICE FOR CONTROLLING PUMP TORQUE FOR HYDRAULIC CONSTRUCTION MACHINE

Document Type and Number:

WIPO Patent Application WO/2004/053332

Kind Code:

A1

Abstract:

The now-existing load factor of an engine (10) is computed to control the maximum absorption torques of hydraulic pumps (1, 2) so as to keep the load factor at a target value. Thereby, the maximum absorption torque on the hydraulic pumps can be reduced during high load imposition to prevent engine stoppage, and the maximum absorption torque on the hydraulic pumps can be reduced without decreasing the engine rpm when the engine output decreases as by environmental changes or the use of inferior fuel. Furthermore, it is possible to cope with all sorts of such main factors in decreases in engine output as cannot be forecast or are difficult to detect by a sensor. And sensors such as an environmental sensor are unnecessary, the production cost being low.

Inventors:

NAKAMURA KAZUNORI (JP)
KOWATARI YOICHI (JP)
ISHIKAWA KOJI (JP)
ARAI YASUSHI (JP)

Application Number:

PCT/JP2003/014638

Publication Date:

June 24, 2004

Filing Date:

November 18, 2003

Export Citation:

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Assignee:

HITACHI CONSTRUCTION MACHINERY (JP)
NAKAMURA KAZUNORI (JP)
KOWATARI YOICHI (JP)
ISHIKAWA KOJI (JP)
ARAI YASUSHI (JP)

International Classes:

E02F9/22; F02D1/08; F02D29/00; F02D29/04; F04B17/05; F04B23/06; F04B49/00; F04B49/06; F04B49/08; F15B11/16; F15B21/08; (IPC1-7): F04B49/06

Foreign References:

JPH03253787A	1991-11-12
JPH0371182U	1991-07-18
US4606313A	1986-08-19
JPH02115582A	1990-04-27

Other References: