Manufacturing times are just pulverised

Innovation and investment in workpiece clamping technology pulverise earlier manufacturing times. The individual clamping solutions from AMF play a decisive role. And so the core components of sheet-fed offset presses are today produced flexibly and with high process reliability using much fewer clamping procedures than in the past. Today, only three clamping procedures are needed, where before eleven were necessary.

With new intelligent AMF workpiece clamping technology, the printing press manufacturer reduced production times drastically and considerably improved productivity. Now, production not only runs faster, but also much more flexibly. Among other things, the experts from Fellbach have equipped six pallets on two processing centres with clamping plates.

A fraction of a hair’s breadth would be much too imprecise

Despite Internet and digitalisation, printing presses are more than ever before a marvel of technology. Their manufacturing is universally considered a supreme achievement and also a speciality of German machine building. For production of the frames, which hold the pressure cylinders, rollers, and drums, as well as the drives for the inking units, coating units, turning drums or other additional modules, such as for embossing, tolerances are only ten micrometres (10 µm). One of our hairs is seven times thicker. Complete frames made of grey cast iron GG25 require a dimensional accuracy and fit accuracy for parallelism and hole patterns that can hardly be imagined with such large parts. The connection surfaces must fit exactly. Only then can the pressure cylinders for the four base colours, multiple special colours and lacquers create the desired print image exactly.

To enable setup on the pallets during production, AMF produces modular clamping fixtures and uses their extensive standard portfolio for the hydraulic clamping elements and the zero-point clamping technology. A DMC 340 U gantry milling machine, including 5-fold pallet changer, is equipped with AMF clamping solutions that minimise set-up time. That includes flexible clamping devices for four variants of components that are clamped and processed in pairs.

Reducing complexity with set-up and clamping plans

A combination of hydraulic pull-down clamps and floating support elements fix the castings in the first and second clamping. As a result, parts are perfectly even. Now the casting skin is removed, the contour roughened, and threads and holes are made. These include the holes for the zero-point clamping bolts that are needed for the third clamping, the direct workpiece clamping, are necessary. The processed castings are unclamped before they are turned. Turned by 180°, the zero-point clamping modules now receive the screwed-in pull-studs and fix the components directly, without distortion, and accessible everywhere for five-sided processing. For more capacity of the pallet changer and maximum flexibility, the machine pallets have AMF zero-point clamping stations, which permit fast and precise fixture change.

But the highlight is the flexibility of the clamping devices. Two movable support plates are mounted on a base plate. Hydraulic support elements, which are easily disconnected, can easily be moved. So the fixtures can not only seat two side parts, belonging together as pairs, which can be processed on five sides after turning, but all four variants of the components can be clamped in the respective processing conditions. To ensure that the workers keep an overview despite this unimaginable complexity, the correct positions for the respective component are colour-coded. That provides the necessary security and ensures speed during advance set-up while production is ongoing. For each component, there is both a clamping plan and a set-up plan, which are available at the machine.

Climate change in the finishing area

These processed components finally reach finishing in a climate-controlled area. There, they adapt to the constant 22° Celsius for 24 hours before final processing on a high-precision Dixi 270 U and calibration on a Zeiss gantry measuring machine. After that, they are ready for installation in the printing press.