The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 25, 2003
Filed:
May. 24, 2001
Hitoshi Horiuchi, Settsu, JP;
Jun Nakatsuji, Settsu, JP;
Daikin Industries, Ltd., Osaka, JP;
Abstract
There is provided an autonomous inverter-driven hydraulic unit in which a command pressure and command flow rate do not need to be inputted from outside and a pressure and flow rate can be autonomously controlled without requiring any input signal wire. A target horsepower calculation unit of a controller judges which of a plurality of regions a point representing a present operating state belongs to and calculates a target horsepower represented by a point on a target pressure-flow rate characteristic line based on the present pressure and present flow rate. A comparison unit calculates a deviation of this target horsepower and a present horsepower received from a present horsepower calculation unit , inputs a control signal representing this deviation to the inverter and controls a rotational number of a variable-speed motor so that the present horsepower coincides with the target horsepower.