At the EMO 2011 show, the Northern Italian machine tool manufacturer Biglia presented its multifunctional turning centers of the 'Quattro' series with the Sinumerik 840D sl control. The mechanical concept, together with the scalable control, provides users with the most diverse off-the-peg turning and milling operations. The result is increased flexibility and higher speeds.
That respectable machine tools are also built in Northern Italy is nothing new. And it is confirmed yet again by the "Quattro" series from the machine tool manufacturer Biglia. These are multifunctional turning centers that are prized throughout Europe for their high reliability and performance power. The machines are available in different versions (see box) from 11 to 15 CNC axes. They are also intended for different turning diameters (45, 52, 65, 71 and 80 mm).
The two opposing spindles form a special feature of the "Quattro" series. This allows the workpiece to be machined from two sides, which, of course, reduces the machining time. The second spindle can also be moved linearly in two directions (lengthwise and crosswise). This provides some leeway in the case of additional milling operations, but it can also be used for automatic workpiece unloading. Two turrets, mounted on the y axis, ensure provision of the necessary tools.
The innovative machining technology thus allows the creation of not only rotary but also prismatic workpieces - all the way to polygons. Dealing with everything in one setup not only reduces cycle times, it also enhances accuracy.
The machines are developed on the basis of a modular concept that ensures flexible application options - from the universal CNC lathe, to complete machining of complex workpieces with powered tools (c and y axis).
Getting it right, from the start
By introducing the Sinumerik 840D sl CNC control, Biglia now wants to expand its previous options and its own market by combining its own technologies with that of the Siemens control.
"In this project, which is of personal significance to all of us who worked on it and of strategic significance for Biglia, we wanted to do everything perfectly right from the start and to get the most out of it", says Giovanni Delmondo, Business Development Manager for machine tools with Siemens Italia.
The result is an all-round successful machine series with a highly modern control that already includes the innovative system expansions of recent months - including increased energy efficiency options offered by the control and drive systems from Siemens.
To illustrate this, Giovanni Delmondo points out "that the fans on the spindles are shut down automatically when they are not required, or certain services such as hydraulics, lubricant supply, or compressed air are deactivated during machine standstill times. This is handled via special screen forms on the control and is extremely simple using the Run MyScreens function."
Also worthy of mention is the standard energy efficiency solution from Siemens in the Sinamics S120 drives. This includes automatic power factor correction or regenerative feedback of the energy generated in braking operations.
Performance and scalability
The centerpiece of the automation concept of the turning centers is the Sinumerik 840D sl control. This is a universal and flexible CNC system, implemented in the Sinamics S 120 design (see Fig. 3). It is suitable for up to 31 NC axes. Whether you are turning, drilling, milling, grinding, laser-machining, nibbling or punching, the Sinumerik 840D sl is suitable for use in the most diverse machining technologies. The CNC control also has PLC (programmable logic controller) functionalities so that a special PLC can be dispensed with, if applicable.
This high-end control from Siemens is suited to medium and complex tasks and plants and can be adapted to the task thanks to scalable hardware. It is also characterized by openness, so the operator interface and also the software present hardly any limits to specific adaptability. This applies all the way to supplementing the NC core; however, a special license is required for this.
In the Biglia turning centers, the control was equipped with the Sinumerik Operate user interface, making operation simple and intuitive. Three different methods of parts programming are possible: Classic ISO code programming, programming with the help of the integrated ProgrammGuide with graphical support of the selected cycles, and the new two-channel Shopturn with graphical 3D simulation. The user is led step-by-step through the cycles, whether in simple metal removal, drilling, thread cutting, pocket milling, groove milling or engraving. Complex programming cycles for complex contours are also possible. The "ProgramSync" function for automatic synchronization of the machining programs via two channels ensures a significant increase in machine productivity. The control is equipped with a 15" monitor and integral keyboard.
The Quattro series from Biglia also uses the highly effective personnel and machine protection system provided by the Sinumerik control concept with the Sinumerik Safety Integrated package.
Biglia is also breaking new ground with servo drives. Thus, the new servo motor generation 1PH8 from Siemens is used for the main spindle motors.
The linear axes are equipped with the also new 1FK 7 G2 series of permanent-magnet synchronous motors. These motor types from Siemens enable on-site replacement of the encoders without having to dismantle the complete motor. Thus, this combination of machine and control with the Quattro turning centers from Biglia truly provides users with full flexibility.
Author: Marco Merlino, Siemens Drive Technologies, Erlangen, Germany
