Общий каталог ZCC-CT 2019 - страница 1113

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A Solid carbide drills

Drill specification and cutting parameters

Chip pocketThe chip pocket ensures that the chips are removed out of the hole during processing.
Helical angleThe helical angle describes the pitch of the flute. It's specified according to the to be mac hardened materials small helical angle largel i hined material. tough materials
Cutting edge length or spiral lengthThe cutting edge length needs to be specified according to the drilling depth, guide bus length. The larger the helical angle, the lower the stability. Since it greatly influences the sible. The recommended min. spiral length is the drilling depth plus 1.5 times of the holei hing length and the whole regrinding l tool life, it should be as small as pos- diameter.
Point angleGenerally the point angle is 140°, for special applications it should be set differently. tough materials, easy to machine small point angle largehardened materials and high-performance drilling
Core diameterThe core diameter is an important factor and influences the stability and the chip flow. low axial cutting force low stability for easy to machine materials small core diameter large high axial cutting force high stability for hardened materials or cross holes
Chamfer widthThe chamfer width influences the guidance and friction of the drill during machining. low friction and bad drill guidance small chamfer width largehigh friction and good drill guidance
Back taperThe drill diameter is slightly reduced from cutting edge to shank to reduce friction duringmachining.
Body clearanceThe area behind the chamfer width. The body clearance is necessary to reduce friction during machining.

B

Deep hole drilling 1 Preparation of the pilot hole with 1534SP03C*

D

– Point angle of pilot drill must be bigger than SL drill. – Diameter of pilot drill must be 0.01–0.04 mm bigger than SL drill. – The pilot hole should be 1–3×D.

2 Entering the pilot hole with SL drill

E 3 Manufacturing the deep hole

– Entering the pilot hole with low cutting speed. (VC: 20–30 m/min) – Stop 1–3 mm before end of pilot hole. (Vf = 0) – Increase cutting speed up to recommended parameter and then start drilling at feed rate.

– Drilling with suitable cutting speed and feed rate. In case of cross holes feed rate should be reduced to 0.05 mm/rev..

4 Pulling out the drill

– After reaching the required depth reduce the cutting speed (VC: 20–30 m/ min) and pull out the drill at high feed rate. (Vf: 2000 mm/min)