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:
Feb. 22, 2005
Filed:
Feb. 28, 2003
Jun Fujita, Mishima, JP;
Ichiro Matsumoto, Numazu, JP;
Kouichi Katoh, Numazu, JP;
Toshiba Kikai Kabushiki Kaisha, Tokyo-To, JP;
Abstract
A numerical controlling unit includes: an inputting part into which a machining program is inputted; an analyzing part that analyzes the machining program to generate an instructed spindle rotational speed and calculates a spindle load ratio of a load applied to a spindle under a machining condition according to the machining program to a spindle load caused when the workpiece is machined: and a distributing part that generates, based on the machining program, a distribution amount per unit period inputted into a feed-axis servo driver. A spindle-rotational-amount-command outputting part receives the instructed spindle rotational speed and outputs a spindle-rotational-amount command for commanding a rotational amount per unit period which is inputted into a spindle driver. A cutting-load-for-judgment calculating part calculates a reference torque value based on the spindle load ratio, the distribution amount, and the spindle-rotational-amount command. A spindle-load comparing part compares the reference torque value with a load torque value which is feedback inputted by the spindle driver and outputs a tool-breakage detecting signal when the load torque value is higher than the reference torque value.