초록 열기/닫기 버튼
Blind rivet nuts (BRNs) are increasingly used in automotive industry because unlike conventional bolt fastening, BRN fastening requires access from one side only. Generally, fastening is conducted using automated units, but manual fastening may be resorted to in case of small quantities. Since the fastening direction is not exactly perpendicular to the sheet metal, the BRN axis is tilted with respect to the plate and may result in damage or incomplete fastening. As the tilt angle (clamping angle ) increases, undesired plate deformation occurs and the contact area of the plate with the BRN fastening area decreases, reducing the clamping effect. In this study, the reduction of the clamping effect with the was investigated to ensure stable fastening force. M6 BRNs were used in the tests. The fastening force was measured as follows: the plate was cut in half through the center of the hole; the BRN was inserted into the hole and fastened; and the clamping angle was measured (values, 0° ≤ ≤ 9°). The force leading to the separation of the halves was measured using a universal testing machine (UTM). The maximum range, in which the fastening force remains stable, was determined. Finite element (FE) analysis confirmed that the fastening force decreases approximately linearly with increasing . Based on the experiment and FE analysis using various , the fastening force was found to decrease with . Further, the maximum tolerance for that provides secure fastening without damage is suggested.
