The Hirschvogel Automotive Group has achieved success with a wide range of automotive manufacturers and suppliers throughout the world.

The company manufactures components for powertrains, chassis frames and engines, as well as for diesel and fuel injection systems.

Moreover, demand is increasing at such a rate that a turnover of 1 billion euros will soon be reached.

The main plant in Denklingen, Germany, manufactures parts using hot, warm and cold forming processes, as well as rotary swaging operations; and without a high degree of tool-making expertise, it would not be possible to ensure the required product quality.

This expertise has recently been complemented by a new CAM system — HyperMill from Open Mind Technologies (www.openmind-tech.com), which has a UK subsidiary in Bicester, Oxfordshire.

Robert Haug, head of planning and NC programming at the Hirschvogel tool-making facility, said: “Thanks to the introduction of the HyperMill MAXX Machining performance package, the time required for programming the milling machines for many components has decreased, machining times and the load on the machine and tools have been cut, and there are new manufacturing options in the area of five-axis machining.”

Precision in the single-figure micron range is an absolute ‘must’ for the 250 tool makers in Denklingen, and this was a major factor when plans were put in place in 2013 to switch from the previous CAM system to a more powerful solution.

Although 13 systems were considered, it was the significantly reduced programming times that swayed the decision in favour of HyperMill, as tool making always involves small batch sizes.

Hirschvogel makes some 200,000 tools a year, with batch sizes from one to 24. The tools, which range in weight from 100gm to 12 tonnes, are manufactured on 32 machining centres, 17 of which are five-axis types.

To give an idea of how fast programming can now be, NC programmer Günter Fasching said: “In the past, when developing a five-axis NC program for a ‘gear stamp’, I had to wait for about one and a half hours for the tool-paths to be calculated. With HyperMill this takes about five minutes.”

The CAM team in Denklingen has also been able to reduce programming times by using the five-axis-optimised ‘rest material’ roughing function.

Based on a preceding operation, this automatically generates high-speed cutting that is optimised and collision-checked for rest material machining.

A further advantage of ‘indexed’ five-axis machining is that shorter tools can be used, thereby ensuring greater stability and performance.

NC programmer Thomas Karg says that when programming rest material roughing, it was previously necessary to work forward manually — tilt angle by tilt angle — while watching out for various restrictions.

“Now, if you choose the ‘Indexing’ function, you can define the tilt angles for the
B and C axes easily and quickly, using two methods.

“The ‘Planes’ option allows you to generate the tilt angle from the plane normal; in‘3-D mode’, the tilt angles are created automatically within a defined range of angles.

“All connecting paths between the tilt angles are optimised and fully checked for collisions.”

The ‘feature and macro’ technology also helps Hirschvogel’s programmers.

Because HyperMill uses geometric information from the CAD system, features such as holes and pockets are processed in the CAM package, and recurring machining strategies that are typical for a feature are combined with tools and technology data, defined as macros and stored in the macro database.

Mr Fasching said: “In the past, I needed more than a day to program a workpiece with 100 drilled holes; now I need just two hours.”

Hirschvogel’s tool makers also estimate that the use of spiral and trochoidal tool-paths, together with dynamic feed-rate adjustment, provides 10-20% savings in machining time.

Automating tool making

Global competition in the tool- and mould-making industry, shrinking batch sizes and advances in manufacturing technologies can quickly shift the bottleneck of a process chain from manufacturing to NC programming.

This was evident at the tool-making department of Phoenix Contact in the Westphalian town of Blomberg, Germany.

However, the automation provided by Open Mind’s HyperMill CAM software means that Phoenix Contact’s CAM-based NC programming now runs automatically for long periods of time.

The company — a manufacturer of systems and components for electrical engineering and automation — has been upgrading its tool-making department for several years, as Sven Holsten, director of ‘tool shop plastics’, explains: “Today, we control our tool-making department via a shopfloor management system and have been able to reduce waiting times and shorten the processing time of tools by an average of 50%.

“The introduction of automated production processes was equally important, and our tool makers use flexible mixed-process manufacturing cells that accommodate milling, die-sinking EDM, measuring and washing operations.

“Automation was also essential in the area of job preparation. By carrying out process analyses in CAM programming, we identified a series of processes where staff were tied to time-consuming routine tasks.

“This offered some starting points for a process of automation that subsequently considerably shortened the time required for programming and made it possible to partly relocate programming to an unmanned night shift.”

It was Phoenix Contact’s long-standing relationship with Open Mind — and its need to automate the area of job preparation — that prompted the CAM company to further develop the automation options offered by its HyperCAD-S and HyperMill software solutions; it is now easy to store complete and flexible CAM programming scenarios that can be re-used and run on an event-driven basis.

At the beginning of 2017, these developments began providing Phoenix Contact with a measure of success.

Now, about half of all orders in electrode manufacturing are fully programmed in an automated batch run. For the rest, programmers must still intervene manually to varying degrees, although they are still relieved of many routine tasks.

Those responsible for tool making are expecting to see similar benefits in the programming of moulds, dies and cavities.

Andreas Leser, Open Mind’s sales director for Germany, says: “With our approach, the user can develop various programs and additional functions that allow automated CAM programming procedures.

“This technology enables the user to access a library that allows functions from HyperMill and HyperCAD-S to be integrated into comprehensive and easy-to-change programming scenarios.”

Graduate engineer Johannes Nittinger from the Laboratory for Machine Tools and Production Engineering (WZL) at Aachen University worked out the basics for automation as part of his doctorate.

He said: “Before starting to consider the automated programming of a component, all the fundamental processes of CAM programming must be clearly specified.

“This includes component analysis, tool selection and the choice of suitable features.

“Because CAM programming differs in complexity depending on the type of component, the automation team worked in stages, starting with electrode programming, then mould assembly and the programming of the mould plates.

“The final stage involved the injection-moulded tool cavities.”

Nils Domack, from Phoenix Contact’s tool-making department, said: “This new form of programming is saving both time and money when it comes to producing the graphite electrodes.

“More than half of all our electrodes can already be programmed automatically — from importing the CAD data through to exporting the finished NC data. In these cases, the CAM programmer now just takes the role of ‘tester’.

“If a component has surfaces for which the HyperMill automation cannot find a suitable tool, they are highlighted in colour by the system.

“When carrying out the test run, the CAM programmer can then see exactly where they need to intervene. Before the NC program is finally released, the programmer must initiate a complete simulation of the machining process in order to ensure that the subsequent processes are reliable.”