Rohm Norm RN 1391 Informaciones Y Directivas Generales Para El Empleo De Instalaciones De Sujeción Accionadas Por Fuer página 52

2 | Reference Speed and Clamping Force Calculation
Calculation (example)
Having:
1. Workpiece and machining data:
Material
Clamping diameter d
Bit diameter (in solid material)
Feed:
Depth of cut:
Speed:
2. Chuck data
Power chuck KFD 200
Jaws with diamond style clamping surface
External clamping with UB 538-04 top jaws at mid position of clamping range
Chuck in new condition (no special influencing parameters)
Find
1. Required clamping force F
2. Initial clamping force F
3. Actuating force
Solution
1. Cutting force (Formula 4)
F = s · t · k
sBo
s · t from Table 1 (or calculated)
k from Table 2
c
2. Required clamping force
Resultant force F
factor S
Clamping ratio
3. Check whether effective centrifugal forces occur on the jaws at a speed
of n = 200 rpm. As this is not the case in this example, we have:
4. Initial clamping force F
S from VDI recommendation 3106 = 59.00 kN
sp
5. Obtain actuating force from the "clamping force/actuating force" diagram
for KFD 200. For a clamping force of 59.00 kN the actuating force is
29 kN
6. Counter-boring (drilling with the drill steel)
The calculation described under "A. Turning" applies analogously.
52 / 138
(roughed):
sp
spz
spo
= 0.3 · 15 · 2.70 = 12.10 kN
c
from Table 7 (previously F
R
from Table 5) Clamping coefficient μsp = from Table 4
z
from Table 3 (or calculated)
= S
spo
d
sp
s
t
n
15.70 2.0
0.2
vax
. F = 1.5 · 39.25 kN
sp spz
= C 45
= 60 mm Ø
= 30 mm Ø
= 0.3 mm
= 15 mm
= 200 rpm
0.25
39.25
from Table 6, safety
RN-1391