Implementation of a die cart system results in die changes in 20 minutes rather than two hours.
Parts had been manually moved through dies. Now a tri-axis transfer system does it. Press cycles are doubled.
Ignacio Prieto, manufacturing and technology manager of Metalsa, a member of the Proeza group, and his colleagues had a problem, the likes of which many people at other companies in his position would like to have.
Metalsa, which is based in Apodaca, Mexico, is a manufacturer of truck chassis and engine cradle components. It has been in business for 40 years. Early on, the company was producing 20,000 frame components a year. In 1996, the employment stood at some 1,700 people, working two shifts. The output was on the order of 320,000 frames.
It is important to note that 80% of the components produced in Apodaca are shipped either to the U.S. or to Brazil. The company's customers include Chrysler, General Motors, Ford, Freightliner, Blue Bird, Mercedes Benz, Thomas Built, Oshkosh, and Dina. These are companies that are demanding high-quality and reliable deliveries. The 320,000 frames are based on 35 different chassis models that Metalsa produces for its customers. Prieto's objective, as he puts it, is "to be competitive with North America's best auto parts stamping companies." Given its customer list, the company seems to be doing a good job.
So what's the problem? According to Gustavo Andres, Metalsa manufacturing engineer, "We had to increase production and find a way to meet customer demands for faster part delivery. We also needed to be more efficient moving dies and parts, and we had to do this without adding presses."
Although labor costs are comparatively low in Mexico, the decision was made to implement automation, not more muscle, on the press lines. Andres stated that initially, some people were worried about how automation would effect their jobs. "We told workers that automation would improve their quality of life on the job, and increase business so that more jobs could be added. Our workers had to understand that they could produce more and better quality components while doing less work," he said.
The whole issue of quality permeates Metalsa. Andres observed, "Our company philosophy is `calidad como forma de vida'—`quality as a way of life.' It means our culture, plus tools, plus leadership gives us quality."
One of the presses in the facility is a 800-ton Danly. It is used to produce frame blanks. This is a heavy-duty job: the coil steel is from 1/8-in. to 1/4-in. thick; blanks weigh 18-lb. to 20-lb. Initially, blanks were hand stacked. In order to accommodate the worker, it was necessary to run the press at six cycles per minute.
The automation change: the implementation of a blank stacker built by Atlas Technologies (Fenton, MI). This permits the press to run at 20 cycles per minute. What's more, blank quality is said to be higher due to the elimination of damage from manual stacking. The stacks are aligned more precisely, thereby improving the feeding into other presses. Also, because there are various parts run, die change was an issue. Hit-to-hit time after a die change was taking approximately 2 hours. So a dual-station die cart built by Atlas (one station for a prestaged die; the other to accept the die being removed from the bolster) was installed. Die lifters and rollers were installed in the press. Die changes are being made in about 20 minutes.
There is a 1,200-ton Komatsu press that is used to produce chassis parts. Depending on the particular component, there are as many as six operations performed, as in: blank, pierce, first form, trim, second form, restrike, cam/piece, trim. Movement of the parts through the dies had been a manual task. This kept the press cycles at no more than 9 per minute. To improve throughput—and the quality of life for the workers—this manual operation was turned into an automatic one through the implementation of an Atlas destacker and a FLEX 5000 tri-axis part transfer system. The part transfer system is equipped with shovel-type fingers that clamp and unclamp, lift or lower, and transfer the part through the dies. It not only accommodates changeovers, but it also allows the press to run at 20 cycles per minute.