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:
Dec. 24, 2024
Filed:
Jan. 15, 2021
Mitsubishi Electric Corporation, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An automatic screw tightening method includes measuring a datum on time-varying screw tightening torque from a motor and a datum on time-varying motor rotational speed between a screw tightening start time point for a male thread with respect to a female threaded hole and a screw tightening completion time point; extracting a plurality of features from measurement-based data on the time-varying screw tightening torque and the time-varying motor rotational speed; and determining, with use of the features, whether a tightened state of the male thread is fit or unfit. In the determination, determining a unified numerical index from the features is included, and the numerical index is compared with a predetermined threshold in the determination of whether the tightened state is fit or unfit. The numerical index is a Taguchi (T) method-based overall evaluation measure from the features.