Page 34 - Welding Robots Technology, System Issues, and Applications
P. 34
Welding Robots
18
which arises on its borders during the glass manufacturing cycle. In fact, most of
the automobile glasses, namely front, rear and roof glasses, are composed of two
sheets of glass joined by a layer of PVC. For proper assembly, and to ensure proper
joining of the PVC to the glass while maintaining transparency, the glasses go
through a heating process, followed by a considerable period inside a pressure
chamber. This process generates a very stiff excess of PVC on the borders of the
glass that must be carefully removed, since it alters the dimensions of the glass,
causing difficulties in assembling it in the car body, and can have esthetical
implications if for some reason the glass borders are not hidden.
Figure 1.8. Robotic glass deburring system
Traditionally this excess of PVC is removed by hand using small cutting devices.
Nevertheless, for highly-efficient plants this is not desirable since it slows down
production, and requires very high concentration from operators to avoid touching
and damaging the glass with the cutting device. Consequently, the process is very
risky for the quality of the final product. Furthermore, with recent car designs some
glasses are glued directly in the chassis without any exterior rubber. This happens
mainly with roof, front and rear glasses. Consequently, the requirements for perfect
PVC removal are even higher, which demands an automatic procedure to execute
it.
The system (Figure 1.8) designed to handle the operation described above is
composed of [36]:
