3 Fundamentals of press design

312 Sheet metal forming and blanking
Fig. 4.6.25 Blank welding line with continuous part handling system for the manufacture of
welded side members (cf. Fig. 4.4.12)
overlapping blanks together, and the stationary welding rolls. Alternatively,
the blanks can be stationary and the welding rolls may move.
Laser technology using CO 2 or solid lasers has proven successful as a
new production technology. However, when this method is used the
two sheet metal edges to be welded together must be prepared for the
welding process by laser cutting or by high-precision fine shearing.
Welding itself is performed with the blanks stationary and a mobile laser
focusing device or with moving blanks and a stationary focusing device.
The working speeds are comparable to those of a resistance welding
unit. In the case of coated sheet blanks, it is actually possible to achieve
higher working speeds. The benefit of laser welding is that no weld overfill
occurs and even coated blanks can be processed without problems.
A third system, which is not yet used on an industrial scale, is
equipped with an induction welding unit. The blanks are pressed together
at the edges. The welding process itself is carried out at high speed, as
the blanks are joined over the entire length of their edges within about
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998