FabShop Magazine - March 2012 - 5

››› lasERs
It has produced parts for appliances, alternative energy products, medical equipment and automobiles using simultaneous engineering, total program management and just-in-time delivery methods to provide its customers with outstanding product quality in an efficient, cost-effective manufacturing environment. To produce stamped automotive sheetmetal parts that are welded together, companies that do this work have three options: They can MIG weld a part, use spot welds or laser weld them together, says Jeremy Dutzy, senior assembly engineer at Ogihara. The choice usually comes down to part-cycle times, cost, how many parts are needed, when the parts are needed and overall assembled part quality. “Equipment decisions become part of the quote process, as the automotive OEM notes that the parts need to be welded, but not how it’s done.” The OEM typically dictates how an assembly is welded together, however, a supplier is free to propose (for competitive advantage) an alternative method of welding if it offers the OEM a significant savings. “The biggest comparison of these three processes is cycle time for part production,” mentions Dutzy. “With a laser, the cycle time is just so much faster. For instance, on a truck door assembly, we are producing 19 laser welds in 16 seconds, which also includes the robot moving. We are laser welding 20-mmstraight line stitches compared to 6-mm-round spot welds. “Now if you compare this to a spot welding manufacturing cell, on average, this process would take approximately 58 seconds to do the same number of welds, almost tripling the cycle time. Then, to meet the customer’s cycle time using spot welding, we would need multiple fixture stations to place the stamped components together.” With the laser, the company’s operators load the parts that need assembling into one fixture. Instead of having multiple fixtures to do spot welding, laser welding only requires one, which saves fixturing costs also. To spot weld parts, Dutzy says the company would need two cells to meet cycle times. Or require multiple geometry stations where some of the parts would be spot welded, and then picked up and placed in another welding station for more work. “The amount of fixtures required to produce an assembly can be reduced by about 33 percent on average,” he explains. “We have done studies on this. We’ve looked at the differences between spot and laser welding and found significant differences. That’s why we’re using lasers.” But along with cycle times there is also

hen Tier 1 auto suppliers quote work, a penny’s difference in price, or fractions of one, can make a difference in winning the contract. Therefore these companies look for any production advantages when building a part faster, better or less expensively (and especially less expensively) when quoting. And Ogihara America Corp., a Thai Summit Group Company, is no different. But they’ve found a way to increase quality while reducing costs for assembled parts. Ogihara has been a Tier 1 and 2 supplier to the major automotive OEMs for sheet-metal stamping for 20 years. At the company’s facility in Howell, Mich., it provides customers with world-class engineering, stamping and assembly capabilities along with tool and die design and construction, modification and refurbishment.

A fiber laser is used to stitch weld this part together. It uses much less flange area than spot welding.

FabShop Magazine - March 2012

Table of Contents for the Digital Edition of FabShop Magazine - March 2012