Machine Tools 4.0, which is part of Schaeffler’s efforts to digitise the production process, connecting existing technology, from sensors to the cloud, to new digitised components, ha s been deployed within its own volume production.
The turning and milling centre, developed jointly with DMG MORI, has been in use for six months at the Höchstadt a. d. Aisch production location in precision soft steel machining of large, customer-specific rolling bearing rings with threads, milling, fits and so on.
Just two years ago a project team started formulating the requirements for the future ‘Industrie 4.0 Production System’ in Höchstadt, Germany, which is representative of many other production processes:/p
• Produce small lot sizes cost efficiently
• Have short set-up times
• Rapid and lean engineering processes
• High process stability, despite very small lot sizes
• Flexible production units,
• Maximum delivery reliability and shortest throughput times
• Lowest possible defect costs even with the smallest lot sizes.
These requirements not only went into the design of the Machine Tool 4.0 itself, but also determined the selection and modification of the direct environment of the machine tool. So we are talking about a 4.0-compatible production cell, which also includes a 3-D measuring machine, a tool preset device, a new kind of clamping system and a laser marking system integrated into the machine tool.
With the latter, each part is clearly labeled per data matrix code. With the individual identity of each workpiece thus determined, all drawings, process data and quality data from the machine and the peripheral devices are stored in the cloud specifically created for this purpose.
Self-Optimising Production Cell
The networking of the machine with the peripheral devices and intelligent processing of the data made it possible to implement self-optimising processes.
For example, the basis was established for an adjustment of the clamping forces during operation. The NC program, measuring machine and clamping system form a control loop. Higher clamping forces during rough machining permit greater rates of feed and lower clamping forces during smoothing lead to smaller form tolerances more productivity with more precision at the same time truly adds value.
The specialists accomplished a similar scenario with the tool preset system: The tools are measured optically, the geometric data are digitalised and made available to the machine and/or NC program online. The NC programs are as such no longer compiled on the basis of ideal tool data but with real tool data that also includes tool wear. This results in less adjusting and retrofitting work on the machine.
Automatic Lubrication Of The Linear Recirculating Guidance Systems
A further control loop of the production cell consists of a standard linear recirculating roller guidance system with acceleration sensor, evaluation electronics and the automatic lubricator FAG Concept8.
The acceleration sensor records minor deteriorations in the lubricant condition in the carriages via minimal changes in the oscillation pat tern and initiates relubrication with the lubricator. The objective of this system is to lubricate as needed and no longer based on time or stroke-controlled.
Two effects are important here: The lubricant requirement is reduced by up to 30 percent and at the same time the smoothness and the oscillation behaviour of the recirculating system are constantly monitored and thereby the quality of the manufactured work pieces is guaranteed.
APMEN Sept 2016
