Custom Motion Control Solution
In this DECI success / application story, we would like to hi-light the brining together of DE Engineering and the capability of our partners: Milwaukee Cylinder, Continental Hydraulics and Delta Computers.
We were approached by an automotive customer who needed to crush (destructive test) their parts periodically to verify the integrity of the assembly. As the parts were part of a crush zone, with a certain amount of energy absorption required, they also needed to keep statistical data of the crush and trace it back to production runs.
After looking at various press manufacturers who specialize in this destructive testing, they found that they were struggling to get the performance they wanted at a price they were willing to pay. They approached us and said “hey you do hydraulics; can you help us with this”. We said “sure, this is in our wheel house, what do you really want.” This led to a discussion about forces, timing, and data acquisition.
Over a number of years, we co-developed and built a series of different size presses ranging from 50 tons (approx. 16” x 16” platen) to 90 ton presses (approx. 24” x 80”). Some frames the customer built and supplied, some frames we designed with Milwaukee Cylinder and supplied. Some were a single ram and some were dual ram with synchronized motion. One also included multiple high speed cameras which captured the crush visually as it occurred so that it could be compared to the crush forces. The crush data was overlaid on the video in real time.
The key to these presses was the Delta Motion controller. The Delta provided accurate and consistent velocity during the pressing sequence, as well as capturing the input from the load cell – monitoring tonnage. The data was then exported as an excel, xls file. This data we were then able to graph visually the results of the crush, as well as give a pass / fail criterion.
The final number of data points for a crush was typically in the 1000-2000 point range, at about .5mm increments every 1/10the of a second. We found that was a good place for efficiency and accuracy. But, it is capable of collecting data at the 1mS level, which at an average crush velocity of 2mm/s results in a data point every .002mm or just under 1/10th of a thousandth of an inch. At a standard crush distance of 120mm that comes out to 60,000 data points.
Along with the crush data, we captured the operator ID, date, time, and lot numbers of key sub assembly pieces. This info we then presented to the quality and engineering department as a single page PDF for their long term records. The raw data and video file we also pushed to their server for long term storage.
We are able to keep track of the extension of the press well into the 4th decimal place, as well as keeping track of forces +/- 90 lbs. on the 90-ton press.
If you need a custom solution for your application, the Donald Engineering team is here to assist you. Contact us today!