A Machine inside the machine

March 07 2011
Machines fo large-dimensioned work-pieces

The large-dimensioned work-pieces having a dozens of tons weight must be manufactured by machines capable to perform the whole machining cycle  in a single positioning meanwhile keeping the requested accuracies.The Aries 5H ( FAF ) milling boring machine  manufactured by  Innse-Berardi allows to reach these results by keeping the high productivity,  also thanks to the  use of the new machining unit that further increases its potentiality.

Within the field of instrumental goods, the sector of big dimensioned work-pieces mechanical machining is still a reference as well as a lucky area in which manufacturers and final users are looking for new business opportunities. The catalogues of Machine Tools Manufacturers integrate new models  proposing several variations; in this way the Customer has the possibility to choose within a wide range of  products having similar characteristics. The potential final users have to face a wide range of  product offers and prices, that makes extremely difficult for the Supplier to reach a choice that sometimes is leaded only by the economical conditions ignoring  a large group of performance indicators that are of basic and fundamental   importance within an investment evaluation.

The Right Choice

The design and  manufacturing know-how, concerning customized and multi-purpose solutions, flexibility and productivity, reduction of set-up times, reliability and accuracy on the work-piece availability of the manufacturing Company as well as its capacity of innovation are some of main performance indicators to be taken into consideration by final users during their  selection to buy a manufacturing system. 

In order to face the more and more increasing request for  productivity and reliability  of machining systems  operating in the leading sectors of the worldwide economy, especially  in the power sector, Innse – Berardi S.p.A. designed and manufactured  a new machining unit for big-dimensioned, horizontal axis, Milling-Boring Machines to be installed in and to complete the existing Aries Line.   This machining unit  is the ARIES 5H (FAF) Model. The work-pieces of the energy-production market are reaching more and more considerable dimensions and weights; by the Aries machines are often manufactured  Turbine cases and compressor cases as well as other work-pieces having diameters higher than 4.5 meters and 6 meters of height.

The Aries 5H Model (FAF) is the Leader Product  of Innse-Berardi range of production  and the main reference for the worldwide sector of large dimensioned milling boring machines.

The high number of installations all over the world, the increasing requests from the final users and the modern technological trends (materials and tools) allowed the achievement of new targets concerning performance and  process thus permitting to the manufacturer and to the final user to face  (and to win) the continuous market challenges.

The Research & Development activities carried out within the I-B Company involve suppliers and potential Customers on the purpose of Design for Manufacturing, Assembly, Quality e Maintenance according to Camozzi Group standards.

Particular attention has been paid to the preventive analysis of failures and breakdowns by the FMEA (Failure Mode and Effect Analysis) and to the static and dynamic checks of the head action by FEM (Finite Element Method) with  a Time to market of 10 months for product and process.

The importance of dimensions

The new boring and milling unit can receive a wide range of boring spindles from 260 - 280 -300 - 320 mm of diameter with pertaining Z axis travels till to  1.800 mm capable to perform boring operations on big dimensioned work-pieces. As far as the head is concerned, it offers a W axis travel till to 2000 mm; the max. total travel of Z + W axes of the machining unit therefore is  3.800 mm.

As in all the other models manufactured by Innse-Berardi, also  in the Aries 5H Model (FAF) the W axis free movement is obtained by means of  hydrostatic and preloaded sliding ways that is  an usual characteristic  in all the large-dimensioned machine tools granting important advantages such as: absence of wear in sliding ways, high level of stiffness and of the prismatic torque, strong decrease of vibrations, absence of stick slip phenomenon, and the best axis positioning accuracy. 

A set of sensors (movement, temperature and vibration sensors) check different physical parameters to grant stability, accuracy, and reliability for a long time by means of programs specially developed by Innse-Berardi S.p.A. The operating unit installed on the special vertically-moving saddle, allows to the Y axis (vertically moving axis)  to slide on a 10 meters travel  by means of an hydrostatically fed screw. The arrangement of the above mentioned travels, in addition to the X axis travel, allow machining operations on large volume work-pieces such as those of the energy field.

The elevate torque available on the spindle in continuous running S1 of 32.000 Nm,  and the elevate rotation speed until to 1.800 rotation per minute  allow to satisfy any accuracy level requested for machining operation.

The existence of a wide range of special attachment heads automatically hooked, clamped and that can be oriented  in the space, make this movable column milling-boring machine extremely flexible for the wide variety of work pieces that it can  machine.

Accuracy can be reached and kept by strategic actions

The more than decennial experience matured in the field of mechanical machining with particular attention to accuracy in machining of large-dimensioned work pieces and the continuous technological growth of research and development has allowed to generate static and dynamic adjustments. In particular, it is possible to counter-balance the bending of the machining unit and of all its installed accessories along the W axis movement to compensate the temperature of the head modified by the presence of bearings and movement generating chains as well as by the body shop temperature.

In addition,  also the boring spindle extension and the head extension are measured and modified, the hardware and software solutions making these dynamic modifications possible allow to obtain dimensional shape tolerances and surface finishing of work-pieces as to satisfy  the Customer’s requirement.

By this new, tested and well appreciated machining unit a new life cycle of Aries Models begins, granting productivity, accuracy and reliability aimed to a continuous  improvement of quality and productivity.

From the particular to the universal

The creation of the new universal head Model TUM 40 L was originated by the success of the new machining unit as far as performance, stiffness and  accuracy are concerned. The attachment head is equipped with C and A continuous axes, in the denomination  TUM 40L, the letter “L” means “extended”  in fact it is an head that allows 5-axes deep machining operations.

The TUM 40L head, owing to the frame of the main head Aries 5H (FAF) and of the machine itself, can reach 1.600 mm of length.

Arranging the machining movement of the W axis (main head feeding) and the V axis movement (table feeding) this attachment can machine complex work-pieces by reducing the number of set up.

As a consequence a reduction in the cycle time and an increase in the accuracy of the finished workpiece. In addition to the evident and mentioned advantages the results of this application are reflected on all the body shop. In fact, being these work-pieces having huge dimensions and heavy weight  (thousands of tons) the 5 axes machining makes the difference.

An simply extended attachment would request  another workpiece positioning.

The position reading of both the axes is a direct one to increase the accuracy. In order to obtain power in removal, it is absolutely necessary to keep high the system stiffness: the TUM 40L head frame has been optimized by the most modern calculation systems in order to reach the above goals. In this way the final users can perform removal in fixed positions by using also the dedicated clamping systems.

Source : Tecnologie meccaniche, written by editor , march 2011