Recently, Italian machine tool manufacturer Biglia introduced its multi-functional 'Quattro' series of turning centers, offered with Siemens’ Sinumerik 840D sl CNC as the control platform. The mechanical concept, it noted, together with the scalable control, provides users with a valuable array of standard turning and milling operations, and the result is increased flexibility and higher speeds for machine operators.
The "Quattro" series are multifunctional turning centers developed for reliability and performance power. The machines are available in versions featuring 11 to 15 CNC axes, and intended for different turning diameters (e.g., 45, 52, 65, 71, and 80 mm).
The two opposing spindles form a distinctive feature of the "Quattro" series: the design allows the workpiece to be machined from two sides, which reduces the machining time. Also, the second spindle can be moved linearly in two directions — lengthwise and crosswise —which provides some leeway in the case of additional milling operations, but it can also enhance the productivity and flexibility of the shop by making the machine available for automatic workpiece unloading. Two turrets, mounted on the y-axis, ensure proper positioning of the necessary tools.
This innovation means it is possible for the operators to initiate not only rotary processes, but also to work on prismatic workpieces – including polygons, according to the developers. Dealing with everything in one setup reduces cycle times, they emphasized, and enhances accuracy. The machines are developed according to 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.)
By offering the Siemens Sinumerik 840D sl CNC control, Biglia aims to expand its designs’ performance options (and its market) by combining its technologies with Siemens’ control expertise. "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 perfect right from the start and to get the most out of it,” stated Giovanni Delmondo, business development manager for machine tools with Siemens Italy. The result is a successful machine series with an advanced control concept, one that already has shown its flexibility by incorporating functional expansions (like increased energy efficiency) available from the Siemens control and drive systems.
To illustrate this, Delmondo pointed 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."
Performance and scalability
Also notable is the standard energy-efficiency solution in the Sinamics S120 drives. This includes automatic power-factor correction or regenerative feedback of the energy generated in braking operations, a substantial factor in energy savings.
The core of the automation concept for Biglia Quattro turning centers is the Sinumerik 840D sl control. This is a universal and flexible CNC system, implemented in the Sinamics S 120 design. It is suitable for up to 31 NC axes. Whether the operator is turning, drilling, milling, grinding, laser machining, nibbling or punching, the Sinumerik 840D sl is a suitable controller for multiple machining technologies.
The CNC control also has PLC (programmable logic controller) functionalities, so that a special PLC can be eliminated, if applicable.
This premium control from Siemens is well suited to medium and complex tasks and production, and it can be adapted to the task, thanks to scalable hardware. The CNC is also characterized by openness, so the operator interface and the software present few limits to specific job adaptability. This applies all the way to supplementing the NC core of the control, according to Siemens, however, a special license is required for this adaptation.
On the Biglia turning centers, the control was equipped with the Sinumerik Operate user interface, so the operation is “simple and intuitive,” the developer noted.
Three different methods of parts programming are possible: Classic ISO code programming; programming with the help of the integrated ProgramGuide with graphical support of the selected cycles; and the new, two-channel ShopTurn with graphical 3D simulation. The user is led through the cycles, step-by-step, whether for simple metal removal, drilling, thread cutting, pocket milling, groove milling or engraving.
More sophisticated programming cycles for complex contours also are possible. The "Program Sync" 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 Biglia Quattro series also uses the personnel and machine protection system provided by the Sinumerik control concept with the Sinumerik Safety Integrated package.
Lastly, Biglia is using servo drives to establish new parameters for machining power. Siemens’ new-generation IPH8 servo motors are used for the main spindle motors in this series. The linear axes are further equipped with the new 1FK 7 G2 series of permanent-magnet synchronous motors. These units make it possible to replace the encoders, on-site, without having to dismantle the complete motor. This combination of machine and CNC control in the Quattro turning centers from provides users with greater flexibility, according to Biglia.