DEVICE AND METHOD FOR MONITORING LOOSENABLE BOLT-NUT CONNECTIONS

摘要

The invention relates to a device for monitoring loosenable bolt-nut connections. A tight and lasting fit of the bolt-nut connection is of particular interest especially in machines and plants as well as in assembled parts in general, so the tightness of the connection is to be monitored. According to the invention, relative axial twisting between the bolt (2) and the nut (1) is detected. For this purpose, a magnet (3) is secured to the bolt (2). A cap (4) that extends down to the nut (1) is placed over the bolt. Thus the cap (4) performs the same rotational movement as the nut (1). A magnet-sensitive sensor (8) is arranged in the cap (4), across from the open end thereof, above the magnet (3). Said sensor responds to a change in position of the magnet (3) and thus records a relative rotational movement between the bolt (2) and the nut (1). The data generated by the sensor (8) are processed by electronics (9).