Siemens: Perfect Float Glass with 840Di

The automobiles market additionally asks for high performance products. Aside from material costs, the expenses involved in planning, commissioning and servicing also play an increasingly important role.



Cutting tables for the cutting and breaking of flat glass as well as the loading and transportation are vital links in the chain of further processing. There are high demands on the control system to achieve the perfection of a stand alone machine as well as to offer modularity and ensure the availability of the complete processing line. The PC-based Sinumerik 840Di from the Sinumerik CNC controller range with its modularity and flexibility together with the digital drives Simodrive 611U fulfills this demanding set of requirements.



Reliable mechanical and electronic systems



During the actual cutting itself, powerful functions ensure quality and productivity. Optional features in the Sinumerik include "Look ahead" and "Frame". The first of these is a forward-looking program to control CNC speed, guaranteeing a high cutting speed even at short traversing rates. With the aid of the "Frame" function, the program automatically recognizes the exact location of the glass pane on the table. Previously, glass panes had to be pushed against reference edges prior to being scored. This frequently resulted in unwanted scratches and is now a thing of the past. Particularly important is the "gantry function". The parallel drive in the X-direction helps compensate for relatively large cutting tables, spindle pitch errors or reversing batches for specific axes.



A cutting force control operated via an analog output of the Simatic S7 continuously adjusts the cutting force to the current cutting speed, thus ensuring clean edges. The quantity of oil can be proportioned via the second analog output depending on the process.



This system is a true solution for the glass industry because of the openness of the standard PCs PCU50 of the Sinumerik controller. These PCs are required for operation and observation in all applications. Diverse industry software can be operated with this system, e.g., software from well-known CAD associates to optimize cuts or to generate contours and software for proprietary applications.



More flexible with modularity



The modular design enables the customer to combine various machines - in accordance with production requirements and the available space.



Together with the Simodrive 611U digital drives, the modular Sinumerik 840Di has many advantages: It can perform logic and NC functions and is also interoperable with the Sinumerik 810D/840D system family. Using the Profibus DP, it is also possible to link the distributed drives of both main and auxiliary axes to the controller Due to the distributed construction and the small amount of cable required, the space required for the control cabinet is considerably reduced.