Selected articles from July/August 2010 issue published on TheFabricator.com:
Even with many styles of sensors on a progressive die, die wrecks continue to occur. Addressing potential miss hits during the design stage, and using proximity sensors in careful, deliberate ways, can help control the problem.
Challenges faced by stampers in the quest to produce a robust part are magnified when they form high strength steels. As materials increase in strength, the inherent tensile property variability increases. Using products from the family of grades known as the advanced high-strength steels (AHSS) complicate matters even more, since what is supplied from one mill may not be produced in the same way as that from another mill. Understanding how steel is made sets the stage for a more profitable relationship between the steel supplier and the steel consumer. The certified steel properties that come with the coil are useful, but more information about the sheet metal increases the likelihood of success.
To meet the challenges posed by forming HSLA for today's automotive weight-to-strength ratio such a high snap-through and springback, stampers can take advantage of press and tooling features to help. These include using a hydraulic or servo-driven press to perform dwell under load; higher draw pad pressure; higher energy; installing an oversized flywheel and motor combination; increasing draw radius in the part design; separating forms into additional die stations.
The increasing use of lightweight HSS alloys in the automotive industry has complicated the job of building tooling for deep-drawn parts. In addition, price pressure stemming from the use of these expensive materials demands significant scrap rate reduction. Multipoint variable binder-force control can help stampers meet these challenges.
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