CONSTRUCTION MACHINE - HITACHI CONSTRUCTION MACHINERY

Title:

CONSTRUCTION MACHINE

Document Type and Number:

WIPO Patent Application WO/2012/169413

Kind Code:

A1

Abstract:

A construction machine is provided with: a rotating body (1d); an electric motor (16) for driving the rotating body; an operating device (4b) for outputting an operating signal according to an operating amount and operating direction; an inverter device (13) for controlling the electric motor on the basis of a control signal generated according to the operating signal; a position sensor (24) for detecting an actual speed of the electric motor; and a second controller (22) for determining whether at least one of a first condition and a second condition is satisfied, wherein the first condition is satisfied when a sign of a value obtained by subtracting an actual speed (V) from a target speed (V*) of the electric motor which is defined by the control signal is different from a sign of acceleration of the electric motor, and the second condition is satisfied when the difference between the target speed and the actual speed is greater than a reference value Vth and the acceleration is greater than a reference value (βth). By virtue of this configuration, misjudgment and detection failure of an electronic control system can be prevented.

Inventors:

OGAWA TAKASHI (JP)
SAKURAI KOHEI (JP)
MORITA YUICHIRO (JP)

Application Number:

PCT/JP2012/063989

Publication Date:

December 13, 2012

Filing Date:

May 30, 2012

Export Citation:

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Assignee:

HITACHI CONSTRUCTION MACHINERY (JP)
OGAWA TAKASHI (JP)
SAKURAI KOHEI (JP)
MORITA YUICHIRO (JP)

International Classes:

H02P29/00; E02F9/20; E02F9/24; H02P21/22; H02P23/00; H02P23/06; H02P23/16; H02P23/18; H02P27/08

Foreign References:

JP2011026948A	2011-02-10
JP2010106511A	2010-05-13
JP2007228721A	2007-09-06

Other References: