In critical aerospace applications, it is not uncommon to lose millions of dollars a year in wasted time and material whenever worn tooling or forming defects produce subpar fasteners. Keeping a close eye on machine components with our strain based die monitoring is a great way see these problems developing before a defective piece falls in the bin.
The advantage of using compression strain technology over traditional piezo sensors is that we are able to observe signals in compression strain under the thread forming dies. This is more effective than acceleration monitoring due to the ability to measure peak forces during the roll as well as periodic signals caused by chipping in the dies. Other approaches have difficulty because of the rigid die support structure and low frequencies. We work with Caron Engineering to implement process feedback from these sensors. This allows integration with MT Connect, among other options for “smart factory” requirements. More importantly, the process feedback can connect to the PLC or CNC running the process to halt upon an alarm condition (preventing production of bad product).
When measuring strain one can identify specific types of faults, including faults that do not produce high frequencies. Die wear can make quasi-static compression forces rise exponentially but not impart any signals that a piezo sensor would detect. Chipped dies produce periodic signals at 2x the rolling RPM of the fastener (related to relative die velocity). Loose tooling can be expected to produce irregularity of the forming force signature since the relative position of the dies is not consistent.
If you have any questions on our offerings for thread rolling machines do not hesitate to contact us