Universal solution for large chucked parts from Emag

By Niraj M Wanikar, Chief Editor, CNCTimes.com, 2016-09-26 12:13:00

The market for commercial vehicles has seen non-stop growth in recent years, especially in Europe. The industry association ACEA estimates that around 2.08 million new trucks, vans, and buses were approved in the EU in the past year. This represents growth of more than 12 percent on the previous year. Demand for heavy vehicles with more than 16 metric tons was especially high. For the manufacturers, however, this positive development goes hand in hand with a growing technological challenge.

The customers are demanding mobility solutions that are more precisely tailored to their fields of operation. For example, alternative drive systems and more efficient conventional drives are both becoming increasingly important. The indirect consequence is that product cycles in production are becoming shorter and shorter; the number of part families being produced is also rising in many plants.

The implications for the manufacturing technology used can be seen in the example of the VMC 450 MT: This vertical turning/milling center from EMAG Leipzig Maschinenfabrik offers an unprecedented level of flexibility. A multitude of large and complex chucked parts can be machined on it in rapid alternation—made possible by keeping setup work to a minimum.

Manufacturers of commercial vehicles are currently faced with a range of very different challenges: rising sales figures, innovative vehicle technologies, and demands by policy makers for lower CO2 exhaust emissions. As a consequence, the production situation in many companies has been changing for several years now. The market cycle for each engine model has been getting shorter (and each new model brings new part families that need to be machined on the same machines as before), while at the same time the number of parts that must be manufactured in parallel is rising.

What this means for the user of the machine is that the production systems have to be set up for new parts more rapidly. The total amount of preparation work thus increases, while the overall equipment effectiveness often declines. “This is why we've been seeing our customers make a transition in recent years,” Georg Händel, manager of Heavy Parts Technical Sales at EMAG Leipzig. “The trend in commercial vehicle manufacture is moving away from rigid production lines. Instead users are looking for highly flexible solutions that can be set up quickly for many different parts and then provide results with consistently perfect quality.”

Growing success on the market
Consequently, maximum flexibility, minimum idle times, and high quality were important priorities for EMAG Leipzig when developing the VMC MT series. These universal turning/milling centers for machining large chucked parts up to 600 millimeters in diameter and 500 kilograms in weight have clearly enjoyed growing success since their arrival on the market in 2013 and have been used by OEMs as well as supplier companies.

Planet carriers, large hubs, brake components, and differentials of commercial vehicles and agricultural machinery, to give just a few examples, can be machined quickly and efficiently on the machines in the VMC MT series. Why exactly are more and more customers choosing this solution? “With these machines, we have been able to optimize all critical productivity factors to the utmost extent. This combination is extremely unusual for the machining of large chucked parts. What's more, the machines can be configured precisely for nearly any requirement. Not surprisingly, that wins over the customers,” Händel said, referring to the key features of the EMAG design:

The VMC MT series is fundamentally a classic turning machine with an exceptionally powerful main spindle with direct drive—the ideal basis for high precision heavy machining.
The powerful turning/milling spindle is also directly driven. It can be used for turning, drilling, and milling procedures as well as multifunctional technologies.

The tool magazine has up to 80 tool posts. That, together with the integrated tool management system, allows customers to prepare the machine for a range of different parts and also to place many twin tools in the magazine, which are then immediately available for the automatic tool changer if one of the tools in use becomes worn. The tool magazine can also be restocked during operation.

The machine has a large side door for automated workpiece loading, which can be done using a robot or a gantry, according to the customer's preference. Manual loading for smaller batch sizes or for setup is done through the front loading door.
For end-to-end quality management, there are several complementary measuring systems. For instance, the quality of the workpieces is checked by a radio transmission probe, and the quality of the tools by a laser measuring bridge.
The overall design of the VMC series is aimed at achieving a minimum footprint, ease of maintenance, and maximum overall equipment effectiveness.
Tailor-made solutions for the customer

This combination really comes into its own, especially with complex parts. Take for example planet carriers: The part is machined in two operations (OP 10 and OP 20) with a total of up to 15 different tools. Two VMC 450 MT machines are used for this, which are interlinked using a robot—“FLEXline” is the name given to this complete system by the design engineers at EMAG Leipzig. A crucial advantage of this system is that the two machines are used in parallel and independently of each other.

The finished parts from OP 10 are placed in intermediate storage within the FLEXline. This intentionally creates a parts buffer which ensures that the FLEXline as a whole continues to produce even if the OP 20 machining of the entire batch takes somewhat longer than the OP 10 machining. This allows the idle OP 10 machine to be set up for a new workpiece without stopping the process.

“This ultimately reduces the downtime of the FLEXline to zero during a batch change,” Händel explained. Proven EMAG technology brings further increases in productivity. For instance, the highly dynamic axes with their short travel distances also reduce non-productive time and speed up production processes.
Universality increases market potential

Quick part changes, low non-productive times, high machining quality—with these advantages, the experts at EMAG Leipzig see major market potential for their machines. “The VMC MT can be used for both prototype manufacture and full-scale commercial production in the range of 60,000 to 80,000 units per year,” Händel said.
“In either case it offers users a whole new level of efficiency in the machining of large chucked parts. And ‘24/7’ and ‘Industry 4.0’ are not foreign to the designers of the machines, but rather clear objectives for the EMAG FLEXline. That is advantageous for manufacturers of agricultural machinery, the aerospace industry, and machinery manufacturers in general. For us there's no doubt: the flexibility and universality of the VMC MT series will continue to gain more and more favor in the market.”

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