Fineblanking

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Fineblanking is a manufacturing process for non-cutting cutting and, optionally, the simultaneous forming of metal . It allows the production of high-precision parts. In contrast to normal punching , in fineblanking the raw material is held in place by means of a so-called ring spike, following the cutting contour. Only then does a stamp cut the metal in the desired shape. In conjunction with a significantly reduced cutting gap (approx. 0.5% of the sheet metal thickness), a cylindrical cut portion of up to 100% of the sheet metal thickness is achieved. Optionally, forming or embossing can be carried out in further steps within the same work stepbe made on the metal. That is why more and more people are talking about fineblanking / forming .

Compared to normal cutting, fineblanking requires a triple-acting press, which is characterized by a particularly high level of guide accuracy of the ram and a rigid press frame. In fineblanking, the workpiece is pushed back into the tool via an "ejector" and then ejected using the so-called "counterholder force" and then blown out or cleared out. With mechanical fineblanking presses and small stamped parts, stroke rates> 120 strokes / min are often achieved.

history

Fineblanking was invented by Fritz Schiess-Forrer in Switzerland in 1920 and patented in 1922. The inventor of fineblanking and company founder of Fritz Schiess AG built his own Schiess fineblanking presses (30-300 t press power), which are still used today in addition to new presses in his own company. From 1923 circular washers were fine-cut as standard components. The world's first fineblanked part manufactured according to customer drawings was a so-called impact nose (circular ring with a radial web facing outwards) as the heart of an electrical switch for public lighting. This part was produced until 1969 and serves as the company logo. By mid-2016, family-owned Fritz Schiess AG in Lichtensteig , Canton of Sankt Gallen, had produced over 6,800 parts and assemblies according to customer requirements (automotive industry, textiles, hand tools and apparatus, building services, mechanical engineering) . With the moon landing in 1969, several dozen shooting parts landed on the moon, built into Hasselblad cameras. From 1957 various companies, including the toolmaker Fritz Bösch, dealt with the subject of fineblanking and in 1959 put it into industrial use. The Feintool company emerged from a garage company . In the beginning, mainly precision parts for mechanical office machines were produced. After this market disintegrated with the advent of electronic office machines, it expanded to include all areas in which precise metal parts are required in large numbers. The automotive industry is an important user of the technology.

Technology and limits

Fineblanking technology is suitable for almost all types of metal, in thicknesses of around 0.5–16 mm. The weight of the cut parts ranges from 1 gram to 3 kg. Factors influencing the successful use of the technology are the precision of the tools and knowledge of the deformation properties of the metal used. An essential feature is that the parts can be cut and shaped more precisely than with the more popular punching.

literature

  • Franz Birzer: Fine blanking and forming. Economical production of precision parts from sheet metal. Verlag modern industry, Landsberg am Lech 1996, ISBN 3-478-93154-1 .
  • The company> History Website of Fritz Schiess AG