Data processing: generic control systems or specific application – Specific application – apparatus or process – Product assembly or manufacturing
Reexamination Certificate
2002-06-21
2004-04-27
Picard, Leo (Department: 2125)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Product assembly or manufacturing
C700S110000, C700S095000, C700S129000, C700S097000, C700S108000
Reexamination Certificate
active
06728595
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to an NC (Numerical Control) machine tool numerical controller and numerical control method, and in particular, to a numerical controller and a numerical control method for numerical control machine tools performing an orbit control.
2. Description of the Related Art
Recent years have observed the development (Japanese Patent No-3093935) of a turning operation method as a turning operation method for NC machine tools, in which a boring bat (tool) mounted on a spindle is controlled to always be oriented in a radial direction (normal direction) of circular arc by the synchronization of a circular interpolatory movement of a center of the spindle on a plane perpendicular to the spindle and a rotational movement of the spindle, to execute a boring process. This turning operation method, called orbit boring from the mode of movement, is advantageous in that the boring of an arbitrary hole size can be performed with a single boring bar.
The NC machine has controlled axes, which have their maximum feed speeds and maximum accelerations factory-set to be adequate. Disclosed techniques (Japanese Patent Application Laying-Open Publication No. 4-245505) teach limiting the feed speed of controlled axis within a prametrically set maximum feed speed.
As orbit boring takes a radial movement as a cut-in or escape action during operation, with a resultant combination between a feed speed of circular interpolatory movement (as an orbital motion speed) and a feed speed for the cut-in or escape action (as a radial spend), if the orbital motion speed exceeds a certain given value, an associated axis may undergo excessive feed speed or acceleration over a factory-set upper limit.
Controlled axis with an excessive feed speed or acceleration over a factory-set upper limit may suffer from, for example, a torque saturation phenomenon with a resultant lost of control, or an excessive error over a permissible value with a failure to perform a conforming process within a permissible range of precision.
The issue described likely appears not simply in the orbit boring, but also in a contour processing by ordinary circular interpolation, when the feed speed of controlled axis is increased for high-speed operation, with a failure to perform a conforming process within a permissible range of precision required therefore.
SUMMARY OF THE INTENTION
The present invention has been made to solve problems described. It therefore is an object of the present invention to provide a numerical controller and a numerical control method for NC machine tools adapted, in a control that accompanies a circular interpolation, such as in an orbit boring, even when making a radial motion to take a cut-in or escape action, so that feed velocity or acceleration of controlled axis is kept from exceeding a factory-set maximum feed velocity or acceleration, ensuring a conforming process to be performed within a permissible range of precision.
To achieve the object, an aspect of the invention provides a numerical control method for NC machine tools to perform a contour describing control, comprising: calculating a permissible range of a physical index representing one of a velocity and an acceleration of a tool; and controlling the physical index within the permissible range.
Further, to achieve the object, another aspect of the invention provides a numerical controller for NC machine tools to perform a contour describing control, comprising: a calculator for calculating a permissible range of a physical index representing one of a velocity and an acceleration of a tool; and a controller for controlling the physical index within the permissible range.
REFERENCES:
patent: 3596153 (1971-07-01), Brainard et al.
patent: 4178820 (1979-12-01), Gerber
patent: 5077507 (1991-12-01), Mitani et al.
patent: 5200680 (1993-04-01), Sasaki et al.
patent: 5544046 (1996-08-01), Niwa
patent: 5723962 (1998-03-01), Mizukami et al.
patent: 5902077 (1999-05-01), Halder
patent: 6438573 (2002-08-01), Nilsen
patent: 6597968 (2003-07-01), Matsumoto et al.
patent: 4-245505 (1992-09-01), None
patent: 8-126938 (1996-05-01), None
Fujita Jun
Hamamura Minoru
Shiba Kazuhiro
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Masinick Michael D.
Picard Leo
Toshiba Kikai Kabushiki Kaisha
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