Method with Pressed-in Sensors
Pressed-in sensors with integrated amplifier
A new method for direct measurement on the loaded parts of the machine
For the direct measurement of the deformations of loaded parts such as beams, supports and masts which are fitted, for example, on presses, injection moulding or stamping machines or on levers, gearbox casings and brake callipers, tecsis offers a new process in which pressed-in sensors are used.
This method uses a type of sensor with a cylindrical external contour. The sensor is pressed into a reamed hole to measure the extension of the component to be monitored. The hole into which the sensor has to be pressed has a smaller diameter than the cylindrical diameter of the sensor.
The advantages of the measuring method using pressed-in sensors lie firstly in the small space taken up by the sensors themselves and secondly in thevery low temperature sensitivity of the measurement signal which is due to the measurement principle.
Simple fitting and replacement of the pressed-in sensor
The pressed-in sensor is fitted using a commercially available press. To achieve this a hole must bedrilled at a predetermined place in the component in which the sensor is to be fitted. An adapter sleeve is pressed in and the sensor is pushed into the adaptersleeve. The use of an adapter sleeve enables the sensor to be easily changed. The assembly forces are about 10kN which is in a practical range.
Thus the parts in which the pressed-in sensor is fitted can be further machined in the normal flowline. The last process consists of setting the zero and end points (sensitivity) of the amplifier (which is also be integrated in the sensor) with the help of a hand programming device. To set it up a defined load is put on the machine in which the sensitised component isinstalled. If it is desired that the sensor should shut down the machine (for example for overload protection) the endpoint can be determined by running up the machine to the maximum load.
If the pressed-in sensor is put into a series manufactured machine it depends on the complete support system in all project stages. For such a project the following preparation steps are necessary in the procedure planning:
- FE calculation to determine the optimuminstallation place/pressed-in place of the sensor
- Prototype testing on prototypes and longduration test
- Adaptation/integration of the suitablemeasurement amplifier
- Spare parts and replacement policy