Welding jaws, esp. for spot welding - includes fibre-optic sensor element for electrode force monitoring

摘要

The welding jaw has an elastic deformation sensor element (4) as a light path formed on a support (5,6) between two or more optical fibres (8,9) of a light guide system which connects the light path with electrical circuitry (11). The support is fixed to the jaw element (1) such that it follows the elastic deformation. The amount of light absorbed in the light path and transmitted back to the circuitry is a function of the deformation of the support. The support is held on the jaw element at two or more holding or seating regions which are spaced from one another and from the plane of the light path (8',9'). The light path is formed between the output end (8') of a first optical fibre (8) and the input end (9') of a second optical fibre (9). The equipment also includes a switch for switching the welding current on and/or off depending on a measurement signal determined by the electronic circuitry. A device monitors, displays and/or compares the determined electrode force with preset values. One or more temp. sensors are on the jaw element and/or the sensor element. A system calibrates signals from the sensor element. USE/ADVANTAGE - Esp. for spot welding robots used in automobile industry, coach-building etc.. Sensor element allows precise and breakdown-free, continuous detection of actual electrode force.