The Importance of Flexibility in Automotive Machining

(Image courtesy of EMAG.)

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 manufacturers, however, this positive development goes hand in hand with a growing technological challenge. For example, alternative drive systems and more efficient conventional drives are both becoming increasingly important.

As a result, product cycles in production are becoming shorter and shorter while the number of part families being produced is also rising in many plants. Advances in production demand advances in machine tools.

(Image courtesy of EMAG.)

The implications for manufacturing technology can be seen in the example of EMAG’s VMC 450 MT. This vertical turning/milling center is designed for machining a multitude of large and complex chucked parts in rapid alternation.

When plant engineers are forced to set up production lines for new parts more rapidly, the total amount of preparation work increases while overall equipment effectiveness often declines.

“This is why we've been seeing our customers make a transition in recent years,” said 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.”

EMAG’s VMC MT series of universal turning/milling centers is suitable for machining large chucked parts up to 600 mm (23.6 in) in diameter and 500 kg (1102 lbs) in weight. Planet carriers, large hubs, brake components, and differentials of commercial vehicles and agricultural machinery can all be machined one machines in the VMC MT series.

Key features of the EMAG design include:

The VMC MT series is fundamentally a classic turning machine with a main spindle with direct drive
The turning/milling spindle can be used for turning, drilling, and milling procedures as well as multifunctional technologies.
The tool magazine has up to 80 tool posts and 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. Manual loading for smaller batch sizes or for setup is done through the front loading door.
The quality of the workpieces is checked by a radio transmission probe and the quality of the tools by a laser measuring bridge.

As an example of how the machines can be used, planet carriers can be 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. This complete system is called “FLEXline.”

(Image courtesy of EMAG.)

One advantage of this system is that the two machines can be 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.

“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.”

For more information, visit the EMAG website.