Measuring device for separately measuring the axial clamping force and the fastening torque and the components of the latter arising from the thread friction and head friction of a bolted joint without superposition of tensile and torsional stress

摘要

Measuring device for separately measuring the axial clamping force and the fastening torque and the components of the latter arising from the thread friction and head friction of a bolted joint without superposition of tensile and torsional stress by the opposing arrangement of a pressure-measuring element as support for the bolt head and a collar bush as support for the test nut in the base of a sleeve. In this arrangement, the sleeve is mounted rotatably with respect to a base plate. The test nut is arranged concentrically in the hub of a toothed gear which is held rotatably with the aid of a needle bearing in a turned recess of the base of the sleeve, and axially displaceably. The drive is performed by a geared motor via a second toothed gear. Measurement of forces and moments is undertaken in a known way by means of strain gauges and commercially available pressure cells. The friction coefficients in the thread and on the head support can be determined from simple mathematical relationships in helical geometry.