Despite difficult global economic conditions, manufacturing now seems to be viewed in new-found favour – and what the machine tool industry makes and sells today will create the consumer products that will drive tomorrow’s financial recovery.
Speak to those who are marketing machine tools and they seem quite upbeat and ready for the challenge. Their pragmatic approach – stressing slow, piecemeal development and evolution in an industry that has already seen significant change – augurs well for the future Peter Smith, area sales manager for Yamazaki-Mazak, stresses that the needs and behaviour of each customer are unique. While everyone else talks of partnership and close working relationships with their customers, Smith’s experience suggests a less doctrinaire approach, with the flexibility to adapt and respond to diverse customers’ requirements without imposing a preconceived model of how they should relate.
As the world’s largest supplier of machine tools and manufacturing systems,Yamazaki-Mazak has encountered the full range of customers, from those utilizing machines in a consistent way for simply defined tasks to others who demand high levels of flexibility in machine utilization. And the self-financing private company has recently seen strong sales of machining equipment as companies increasingly automate production and use sophisticated control software to produce ever more complex products.
Innovation through integration
Martin Winterstein, chief marketing officer for leading machine tool manufacturer MAG GmbH, speaks enthusiastically of the company’s ability to offer global automotive customers new machining solutions which integrate processes previously performed as separate operations.
This theme of integration would certainly appear to be spreading out across the range of MAG offerings to powertrain customers – integrated honing technology is being used in cylinder block manufacture, with both boring and honing being conducted on the standard CNC machining centres. Also, MAG’s new H 250CDT Hobbing machine, used in gear production, offers the capability to simultaneously combine hobbing, chamfering and deburring.
MAG is confident that the time-saving associated with the integration of these previously discreet processes will translate into significant cost savings as well as an improved quality product. In the case of integrated honing for example, they point to improved pre-machining, resulting in less honing operations – as well as the obvious benefit of complete finish machining being achieved in one set-up. To be assured of appropriate accuracy, highly developed electro-mechanical and hydraulic feed devices are utilized in their machining centres. Precision pneumatic measuring units provide process control.
Tornos is another machine tool producer championing this integrated approach. At EMO in Hannover recently, the firm introduced its new MultiSwiss concept, providing a link between multi-spindle turning centres and sliding headstock machines. With all peripherals fully integrated and an openaccess front, the new machines are claimed to offer minimal footprint and maximum performance.
Compacted Graphite Iron (CGI) is increasingly used in engine block and head castings, especially cylinder blocks and bearing caps, as it offers a significant strength-weight ratio and enhanced stiffness. This, in turn, facilitates the reduction in block wall thickness that designers always seek. CGI does present significant difficulties in the machining process for several reasons. At several times the tensile strength of traditional grey cast iron, CGI demands greater cutting force with a requirement for significantly more machining power. Added to that, the comparatively low thermal conductivity of CGI results in heat pushing into the workpiece with adverse results for tool wear. Tool lubrication is also more complex due to the absence of sulphur within the CGI casting and the presence of abrasive-free carbides throughout the casting as a result of the inclusion of titanium as a constituent of the alloying process. MAG has developed cryogenic machining techniques with throughspindle, through-tool cooling using liquid nitrogen at low flow rates. This offers maximized tool life and improved cutting speeds while holding cutting temperature to an acceptable level.
Other suppliers have, of course, addressed these issues. Sandvik has worked with Makino to produce cutting tools and boring processes to meet the challenges presented by CGI, using a multiple insert tool that is fed down the cylinder in a helical path. A rough bored cylinder can be finished in one pass using this technique with only a subsequent honing operation required before assembly.
A shared knowledge base
MAG is proud of its ability to support customers through the full developmental cycle, including support from experienced honing and machining experts; help with the planning and execution of trials and tests; prototype and small batch production; and turnkey implementation of agile manufacturing systems for high volume serial production.
Of course real gains in efficiency require close work between designers, production specialists and machining suppliers to ensure process and machine optimization. Sophisticated product lifecycle management tools are helping manufacturers and suppliers to approach the production process in a more systematic and informed way. Market leaders Catia and Siemens offer systems and software and work with OEMs to develop and produce products as well as management of the associated knowledge base. As a consequence these same systems have become essential tools for those supplying the sector.
Advances in coating technologies
Heller GmbH is keen to remind us of the importance of coating technologies in vehicle cylinder block production. Working with Daimler Benz it has incorporated its Nanoslide twin-wire arc spraying technology in high-end performance applications where the advantages of reduced friction were paramount. Following the demonstrated success of these applications – the process has been incorporated into the AMG M156 V8 engines since 2005 and more recently for the V6 diesel engine ranges – the challenge now is to push forward its incorporation in high volume applications. Such developments require the development of market-orientated solutions in terms of system supply and services, with Heller committing to the provision of a technical centre for the coating of customer specific prototypes using Nanoslide technology.
Previous cylinder coating developments have a mixed history. On the one hand, offering and delivering significant performance advantages, yet occasionally presenting difficulties in service. As a consequence the development process is crucial.
Nanoslide technology already meets the stringent production rules and criteria of the motor industry and with proven competitive advantage over conventional cylinder lining technologies its adoption in mass market applications is, according to Heller, only a small step away.
Compared to other thermal coating processes, Nanoslide presents itself as technologically superior and highly competitive economically. However, the coating process is demanding in terms of its stringent requirements for optimal coordination of quality-determining parameters such as current, voltage, wire feed and process gas flow.
Contributing to energy reduction
Another key area of concern for machine tool suppliers is energy usage in the production process. As customers become increasingly concerned about the environmental impact of their operations, the machine tool industry has sought to respond. Mapal, for example, claims that enhanced tooling in one application, involving the manufacture of automotive gearboxes, brought significant energy savings. With more integrated processes leading to a reduction in tool changes, the result was a speeded up production cycle and corresponding energy usage reduction.
MAG points to its E-Actuators – energy efficient electronic speed controllers – which offer significant energy savings over conventional hydraulic actuation. Studies show a saving of up to 50% with a typical workpiece in an automotive machining situation. More sophisticated monitoring of energy usage is helping to identify numerous small savings which can be achieved in the production process with a resulting significant cumulative cost and energy reduction.