Title:
BOLT TIGHTENING DEVICE
Document Type and Number:
Japanese Patent JP2022182886
Kind Code:
A
Abstract:
To provide a bolt tightening device that brings the axial force of a bolt closer to a target axial force value by improving the accuracy of detection of a bending point at a change rate of a tensile load with respect to a rotation angle of the bolt.SOLUTION: In a bolt tightening device 30 that tightens a bolt 10 with a tensile load P applied thereto, (a) when the tensile load P is changed by rotating the bolt 10, a bending point (e.g., a bending point O2) is detected, which is a change point between a high variation region and a low variation region at a change rate R of the tensile load P with respect to a rotation angle θw of a wrench holder 46, (b) a target tightening rotation angle θt for terminating the tightening of the bolt 10 is estimated based on a rotation angle θw of the wrench holder 46 at the bending point and an amount A1 of change which is a predetermined correction rotation angle determined by a relation in rotating direction of the bolts 10 between the time of detecting the bending point and the time of tightening of the bolt 10, and (c) the tightening of the bolt 10 is terminated at the target tightening angle θt.SELECTED DRAWING: Figure 4
Inventors:
SAWADA HIROKI
Application Number:
JP2021090663A
Publication Date:
December 08, 2022
Filing Date:
May 28, 2021
Export Citation:
Assignee:
TOYOTA MOTOR CORP
International Classes:
B25B23/14; G01L5/00
Attorney, Agent or Firm:
Haruyuki Ikeda
Kojiro Ikeda
Kojiro Ikeda
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