| 摘要 |
A method and apparatus for tightening a screw joint to a predetermined axial load Fp providing the spring constant k=(F/ phi ) of the joint is known, wherein the torque/rotation relationship M ( phi ) is determined during the linear, elastic deformation part of the tightening process by calculating the joint stiffness (dM/d phi ) at an arbitrarily chosen torque level M2. A theoretical, tensionless angular position phi 0 of the joint is calculated by extrapolating the determined torque/rotation relationship M ( phi ), and the tightening process is interrupted as an angular interval DELTA phi from said theoretical, tensionless position phi 0 has been passed, which interval according to the spring constant k of the joint corresponds to the predetermined axial load Fp. |
