Process for laser beam welding with prior spot welding

• US 20050109740A1
• Filed: 09/17/2004
• Published: 05/26/2005
• Est. Priority Date: 09/19/2003
• Status: Active Grant

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler AG (Mercedes-Benz Group AG)
• Inventors: Todorovic, Vladan, Becker, Wolfgang, Goth, Klaus, Paelmer, Mike, Stahs, Thomas
• Granted Patent: US 7,312,417 B2
• Time in Patent Office: Days
• US Class Current: 219/121.640
• CPC Class Codes: B23K 2101/18 Sheet panels
• CPC Class Codes: B23K 26/082 Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
• CPC Class Codes: B23K 26/10 using a fixed support , i.e. involving moving the laser beam
• CPC Class Codes: B23K 26/22 Spot welding
• CPC Class Codes: B23K 26/24 Seam welding
• CPC Class Codes: B23K 26/60 Preliminary treatment

Abstract

During welding with high output power, the gaps between the pieces being joined may not exceed a maximal gap width. It is the task of the present invention to provide a process for laser beam welding, which on the one hand ensures maintaining (not exceeding) a maximal gap width between the sheets and on the other hand makes possible a maximal utilization of the achievable welding speed. This task is solved in that the sheets, prior to welding, are first spot welded, wherein they are clamped only during this spot welding in order to ensure the maintenance of a maximum gap width.

Claims

1. A process for laser beam welding of at least two pieces of sheet metal comprising:

positioning the pieces of sheet metal relative to each other as necessary for welding,

thereafter spot welding with a laser beam,

thereafter welding with a laser beam,

wherein the process involves alternating local spot welding and local welding multiple times, and

wherein the sheet metal is locally clamped by a clamping device for spot welding in such a manner that locally a predetermined maximal gap width between the sheets is ensured.

2. The process according to claim 1, wherein during the local welding the clamping device is moved to the next location.

3. The process according to claim 2, wherein the relocation of the clamping device occurs with reduced pressure on the sheets or without application of pressure.

4. The process according to claim 1, wherein the spot welding forms an elongated seam.

5. A process according to claim 1, wherein the spot welding and welding occur using a laser scanner.

6. A process for laser beam welding of at least two pieces of sheet metal comprising:

positioning the pieces of sheet metal relative to each other as necessary for welding,

locally clamping the sheet metal by a clamping device prior to spot welding in such a manner that locally a predetermined maximal gap width between the sheets is ensured,

spot welding with a laser beam in the area in which the maximal gap width between the sheets is ensured by clamping,

local welding with a laser beam in the area between the spot welding,

wherein the process involves alternating local spot welding and local welding multiple times.