Flange

Descrizione

The customer, a subcontracting company to the German automotive industry, looked for a machine capable solution to deburr a cross bore. Up to now, the customer had to do the burring manually in a separate operation step .

Application details

Application details

Main bore: Ø89.0 mm
Cross bore: Ø12.0 mm H7
Axle offset: 15.4 mm with angle 5.3°
Material: X15CrNiSi20-12 (Tensile strength approx. 550-750 N/mm2)

Proposed solution

Proposed solution

Caused by the axle offset and the angle, the inner bore edge is extremely uneven what makes it difficult to machine it automatically.

Initially, we intended to realise the processing by implementing 2 operation steps (1x COFA tool rotating clockwise and 1x COFA tool rotating anti-clockwise) and thus introducing a safe procedure. Unfortunately, there was no additional tool storage place available. This is why we started a small trial series using a COFA Special Blade with a clearance angle of 45°.  Involved risk: the „aggressive“ blade could break.

The trials have led to positive results. The fears were not justified. The special COFA8 blade with Alcrona coating was able to stand the load (back machining only). It is important to mention that relatively low cutting values had to be applied in order to allow the blade to continuously adapt to the unevenness.

Machining parameters:
Working speed: 300 rev/min.
Working feed: 0.1 mm/rev.
Coolant: External coolant

Customer benefits

Customer benefits

The new process allows the workpiece to be finished on the machine fully. Apart from the considerable cost savings, a stable process capable deburring process is resulting.