Italian mechanics has development possibilities in emerging sceneries as those of far east and opens its doors to business increase for the leaders of turning.
According to the estimates of Vdw German Machine
Tool Builders’ Association, in 2015 the sale/purchase of machine tools in the world should be at least 65 billion dollars whose 50% is represented by China. In Beijing, Shanghai and surroundings the Italian production stands out first of all for its special high- performance tools, among which the big five-axis lathes.
The turning technical requirements are accuracy, machine range, meant as the ability to carry heavy loads in case of large-sized pieces’ processing and last but not least, their removal potentiality.
The items whose surface and volume are bigger, involve difficult detail handling and this implies the need to obtain finished products with the least amount of positioning possible. Moreover, the processing value increases along with the increase of its dimensions: the imperative is that the machines’ reliability must be such to avoid the need of repositioning the pieces in view of a correction and to eliminate the possibility of a complete gap. The latter is a worrying scenario, because it can cause economic damage to businesses.
Various types and applications
It is easy to note the extent of variables to take into account; for this reason a part of the industry is introducing further distinction elements such as to clarify the kind of pieces to be processed and consequently the lathes’ peculiarities. For rings and low height flange washers of large diameters, processed with fixed cross rail lathes, the required characteristics are high ram stiffness and a table suitable for pieces’ holding in order to minimize the risk of deformation. Particularly, on high pieces with large diameter, such as turbines and valves for plant applications, a considerable ram eversion – whose section must be sized in proportion – is required.
Weights and processing speed often require hydrostatic positioning systems. In general, the third millennium lathes must assure power in terms of kW and strength to carry heavy duty operations to be performed in the more and more compressed market times.
Turning , milling and grinding centers allow processing pieces with 8oo mm diameters up to 18 m diameters with 9 m workable heights and 500 tons weight per piece; but in some cases they can be 8 meters high, workable with portal displacement according to the length requested by the customer. The numerical control systems devoted to the chips’ removal are necessary if they are designed for hard and continuous cuts, in order to maintain extreme long-term accuracy, even for pieces with very difficult mass and dimensions. But if speed is among the most demanded details by the customers of every sector, to resize the cycle times, a high torque is needed in order to facilitate high speed removal even during reduced rotation rates of the spindle. If milling and drilling operations are required for the completion of the piece, to avoid costly repositioning, the high-sized lathe must allow such operations by turret engine. Or, according to a more growing trend, there should be a real turning and milling unit with multi-axis positioning together with a wide availability of tools storage in the warehouse.
The idea of using different machines for roughing and finishing phases, has been superseded by the market not only because of the elevated logistics costs but also because the customers are now turning to the so-called all-in-one solutions, designed to start and complete the entire manufacturing process: all in one. One of the most fascinating challenges for Italian lathes and turning systems manufacturers is embodied now by methodologies and tools that should reconcile the cycle time’s reduction with the precision and the dimensions.
The increasing importance of integrating with the communication technology and computer science cannot be inconsiderable. The high speed of axis translation with last generation linear motors, the rotation of the pieces through high torque synchronous electro spindles and the multi-axis processing units must be managed by innovative CNC.
The most frequent application areas
The Italian-built high-sized lathes have found successful applications in a wide variety of sectors. No doubt the family of extra-large lathes oversees the energy sector. Both for what concerns the traditional sources, with the creation of turbines for thermal and hydro-electric segments, and for what concerns renewable ones, where the leader is wind power, and finally in nuclear power.
In general products such as disks, flanges and turbines are managed by energy and mills, rollers and turbines by power plants. Wind power has different requirements: wind turbines, shafts and gears; along with rotor supports. But turning is often synonymous of solutions for mechanical engineering, which is supplied with reducers, valves, shafts and machine tools, and for shipbuilding. Here, lathes are exploited to shape helixes, crankshafts and pistons, while in aeronautics, that is another popular field of action, they are used to create turbines, carts and propellers.
Another interesting sector that sometimes requires the integration of two or more connected and interfaced turning and milling centers is earth-moving in mining; other important facilities are printing systems, big precision bearings, hard roughing and finishing works and big forging processing. As you can see, application examples are not lacking, and besides entering the Chinese market the domestic turning industry has also entered the Indian market thanks to its specialization in gas turbines. In this area, without continuous solutions, lathes have supplied finishing and combination of already processed torque and vertically positioned semi-shells.
To go back over wind energy, however, it must be said that the turning and drilling of turbine rotors and stators has been the keystone of some important applications that were carried out by halving the drilling times thanks to a double ram with 90 degrees reference heads. But the possible outcomes are even more promising, since recent deliveries of vertical lathes have involved both turbines and discs production as well as that of spherical valves and details once again customized for energy.
In the last years the market seemed to be oriented towards true multitasking machines designed also for milling, grinding, drilling and pieces’ testing, together with tools’ checking.
Precision and speed
One of the most fascinating challenges for Italian lathes and turning systems manufacturers is embodied now by methodologies and tools that should reconcile the cycle time’s reduction with the precision and the dimensions.
No doubt the family of extra-large lathes oversees the energy sector. Both for what concerns the traditional sources, with the creation of turbines for thermal and hydro-electric segments, and for what concerns renewable ones, where the leader is wind power, and finally in nuclear power.