Economical quality control
DasyLab allows workpieces to be allocated very easily to the archived production process data using the batch designation.
The company MEIER Imprägniertechnik makes wheels and axles for railway locomotives. The process of making a locomotive wheel involves heating up a 'tyre' (the outer metal ring on which the wheel runs) and fitting it to the actual wheel. The tyres have to be expanded by a defined heating process. Having been fitted onto the wheel when hot, the tyre contracts around the wheel as it cools, thereby attaching itself firmly.
For this process, the manufacturer required a heating furnace with an easy-to-use visualisation system and comprehensive process data backup for quality control purposes. The company Maier Vakuumtechnik (Bocholt) developed a furnace in which 6 tyres can be heated simultaneously but independently of one another (six drawers). The visualisation and process data archiving functions are performed by DasyLab.
DasyLab enables visualisation and logging of the process data for the individual drawers.
Description of process sequence: the furnace operator places a workpiece in one of the drawers, pushes the drawer into the furnace and starts the process. DasyLab then requests the operator to issue a batch name for the drawer concerned. Once the batch name has been confirmed by the operator, the specified and actual temperatures for the drawer are read off every 20 seconds from the SIMATIC S7-314-IFM and simultaneously displayed in a list on the screen in chart recorder format. It is then easy for the furnace operator to see whether the process is following the required sequence. The operator can also use keyboard shortcuts (e.g. ALT + 1) to switch between the visualisation displays for the various drawers.
At the same time, the process data is saved to a file with the same name as the batch name that the operator was required to enter at the start of the process. This makes the process data very easy to relocate and check when required. In addition, the record of the specified and actual temperature progressions together with the batch name are printed out at the end of every heating sequence for each drawer. That printout can be given to the customer together with the product as proof of the quality.
Opinion of the customer: 'Very well!'
In total, DasyLab monitors and visualises 8 analogue and 30 digital signals for this application and responds to changes in the PLC status with specified actions (e.g. printing out data, storing data, prompting for batch name).
When asked how well DasyLab was suited to this type of application, Mr Tendahl of Meier Vakuumtechnik who was responsible for the DasyLab configuration, answered simply, 'Very well!'.
