Machine Tools Automation solutions enable flexible retooling

Editor: Eric Culp

When automating machine tools, the focus is usually on loading and unloading workpieces. The increasing spectrum of variants, however, calls for flexible solutions from the building set in order to be able to adapt the automation quickly to the altered tasks.

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The PW 3000 pallet changer from Hermle adapts a 5-axis processing centre for bringing in a pallet from the 4-fold store.
The PW 3000 pallet changer from Hermle adapts a 5-axis processing centre for bringing in a pallet from the 4-fold store.
(Source: Hermle)

In looking at the process, one sees machine tools working automatically. This is made possible by components like CNC controls, tool changers or chip conveyors, which today belong to the basic equipment of a processing centre.

For Christian Lang, CEO of Heller Services, the following question is revealing: “How many workpieces are in reach of the machine?” Here the priority is to close the gap apparently arising from limitations on operational staff, he explained. “Automation today aims to give support in workpiece handling in the face of 24/7 production. The goal is 8,760 productive hours per year.”

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Automation can often be shift-dependent

Berthold Hermle equips most of its processing centres with pallet changers or robot systems. “The automation tools are usually placed in front of or beside the machine, attention being paid to access for manual or setting-up operation,” according to Gerd Schorpp, who is an executive partner at Germany’s Hermle-Leibinger Systemtechnik.

The machines are often used for manual activities during the day with tasks such as running in parts or processing batches of one, he explained. Automation becomes the main focus during the second and third shifts.

Looking for a pallet changer or a robot system?

The standardised pallet changers by Hermle are offered in various versions, depending on the machine model. The latest pallet changer, PW3000, has a transport weight of 3000 kg and was developed for the automation of the large processing centres C50 and C60.

A large proportion of machines comes with robot systems in differing weight classes. The priority, Schorpp said, is always the customer-specific design. “Pallets, workpieces, grippers and auxiliary equipment, for example, can be changed and managed in one installation.”

There are few limits on automation. Andreas Mootz, CEO of Emag Automation GmbH, explained: “We offer all automation levels, from simple automation solutions to complete automation.”

Adding automation to 95 % of all machines

He touted an impressive level of in-house automation. “Ninety-five per cent of all machines from Emag are delivered with automation.” As examples of machines with simple, flexible automation systems, he cited the VSC and VL vertical turning machine series. These are equipped with an automation system with a circulating chain into which drag-frames are inserted to enable the transport of workpieces in and out of the pick-up station. The vertical main spindle takes the workpiece up directly from the pick-up position.

“The major portion of the automation is thus transferred directly into the machine,” Mootz explained. “Using this principle, a faster, more space-saving, technically simpler and thus operationally safer and, at the same time, lower-cost workpiece change and transport can be carried out without any re-tooling work.” With just the help of adaptations in the NC program, a broad spectrum of parts can reportedly be automated.

The automation solutions from Emag can be put together from a building set of standardised modules. “Flexibility, however, irrespective of all the savings, is playing an ever greater role,” Mootz noted. “The demand is not so much for automation for particular parts, but rather for universal automation solutions, since often whole families and many workpiece variants can be produced on one machine.”

First the goal, then the path to reach it

Fast retooling of the machine tool and quick adaptation of the automation to altered tasks are said to therefore be a priority. “Developers can only confront these challenges with a modular construction with function building blocks,” according to Mootz.

With the desire for customer-specific automation at the prices of series solutions, Heller’s Lang said he sees a challenge in which one must distinguish between the single machine and a production installation.

“Workpiece storage units are generally standard solutions which are offered as modules and are simply arranged as the customer requires,” Lang explained. “The situation is different with installations. There, the project planning is predominantly customer-specific or, put more precisely, component-specific. Here, questions such as process technology, variant diversity and piece numbers play the decisive role. Many installations, however, are in fact predominantly customer-specifically constructed and configured.”

Heller reportedly produces all components close to the machine itself, including pallet changers and linear or round stores. For robots and other material flow solutions, the firm co-operates with specialised partners. “In almost all cases, however, we remain, as system leaders, centrally responsible for the project,” Lang noted. “We integrate these systems into our complete installations.”

Besides loading and unloading of the machine tool, automation managers said they still see further automation possibilities in equipping and operating the machines and installations. Examples for these kinds of upgrades are said to include automatic fitting of clamping equipment and auxiliary equipment, or automatic loading of pre-set tools into the machine or magazine, connected to the firm’s central tool store.

The future: automated error analysis and correction

As a vision for the future, other features could include automated cleaning and care of machines, even to the extent of automatic replacement of wearing parts. In addition, shops might even be able to expect automated error analysis, self-remedying of faults and even in-built machine maintenance and repair. A version of this report, written by Editor Rüdiger Kroh, first appeared in our sister publication MM Maschinenmarkt.