Method and apparatus for determining the position of a weld groove for laser welding

US4924063A · kind A · utility

Assignee

• Fried Krupp · DE

Inventors

• Manfred Buchel · Mülheim, DE
• Norbert Hangmann · Oberhausen, DE

Key dates

• Filing date: Sep 8, 1989
• Grant date: May 8, 1990
• Expiry date: Sep 8, 2009

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B25J9/1684
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

A laser welding process includes the steps of deflecting, with an oscillating frequency of at least 100 Hz, a collimated and focused laser measuring beam, intensity-modulated with a frequency of at least 200 kHz, across the path of the weld groove during co-travel with the laser welding beam along the weld groove; directing the laser measuring beam to the workpieces; causing the laser measuring beam to impinge on the workpieces at a distance of maximum 10 mm from the central longitudinal axis of the laser welding beam; sensing, by an electro-optical sensor having a single light-sensitive element, rays of the laser measuring beam reflected by the workpieces; generating, by the sensor, measuring signals in response to the sensed reflected rays; applying follow-up signals in response to the measuring signals, and correcting the position of the laser welding beam by the follow-up device in response to the follow-up signals applied thereto.