Machine control: Analog sensor improves drawbar operation

Position monitoring system with electronic analog sensor allows users to monitor machine-tool power drawbars for performance and wear.

By Control Engineering Staff July 24, 2008

Rockford, IL — Advanced Machine & Engineering , (AME) announced its OTT/JAKOB Position Monitoring System with the Electronic Analog Sensor, which, it says, allows users to monitor machine tool power drawbars for performance and wear. According to the company, an electronic analog sensor detects position, and an electronic unit attached to the machine controller transmits the data. This system indicates whether tools are clamped, unclamped or not present. It can increase tool head accuracy and longevity by monitoring cycles and hours, and indicates whether tools are properly held. Because these units transmit information quickly to onboard machine controls, mechanical signal rings with inductive sensors are now obsolete.Monitoring system components include:• Sensors,• Sensor electronics, and• Position-controller.The unclamp unit contains a cylindrical, inductive analog sensor consisting of a primary and secondary coil. As the drawbar connection moves axially through the analog sensor during clamping or unclamping, the target ring on the drawbar connection triggers the output signal. This signal increases as the target ring further enters the sensor, indicating its position. Position is also monitored during the milling process.The sensor electronics supply the primary coil with a signal having constant frequency and amplitude. A demodulator transforms the signal of the secondary coil into a stable dc output signal.The position-controller evaluates this current signal and sets the output signals at the adjustable limits. A digital filter compensates existing peak values. The position-controller is equipped with a meter to display operating hours and operating cycles.— C.G. Masi , senior editor Control Engineering Machine Control eNewsletter Register here and scroll down to select your choice of eNewsletters free.