Version 1.0 - 2020-12-22
112
Translation of original instruction
3440287
│
3442710
│
3442712
GB
K11-
80-10
0-12
5_I
SO-
702-
4_344
0287
_344
2710
_344
2712_
ba-i
nte
grat
ed_
GB.
fm
3.11.2 Basic safety instructions
The permissible speed (as per VDI 3106) must be calculated for the machining allowance;
the maximum guide speed must not be exceeded. The calculated values must be tested by
performing a dynamic measurement.
The max. guide speed may only be applied with max. introduced actuation force and a
chuck that is perfect working condition.
If the chuck is involved in a collision, it must be subjected to a crack test before using it
again. Damaged parts must be replaced using original spare parts.
The chuck may only be mounted and removed, commissoned, operated and maintained by
authorised and skilled staff following safety training.
We recommend checking the clamping force before starting a new series batch and
between maintenance intervals with a clamping force measuring device. Only regular
checks guarantee best possible safety.
3.11.3 Optional soft lathe chuck jaws
CAUTION!
The optionally available soft chucks jaws are jaws, which must be stepped according to
the application. Unstepped jaws lead to an increased centrifugal torque with a reduced
permissible rotational speed of the rotary chuck.
3.11.4 Calculating the required clamping force for a given speed
The initial clamping force F
sp0
is the total force impacting radially on the workpiece via the jaws
due to actuation of the lathe chuck during shutdown. Under the influence of rpm, the jaw mass
generates an additional centrifugal force. The centrifugal force reduces or increases the initial
clamping force depending on whether gripping takes place from the outside in or from the
inside out. The sum of the initial clamping force F
sp0
and the centrifugal force F
c
, is the effec-
tive clamping F
sp
.
F
sp
= F
sp0
± F
c
[N]
- for gripping from the outside in
+ for gripping from the inside out
Legend
F
c
Total centrifugal force [ N ]
M
cAB
Centrifugal force of top jaws in [ kgm ]
F
sp
Effective clamping force [ N ]
M
cGB
Centrifugal force of base jaws in [ kgm
F
spmin
Required static clamping force [ N ]
n
Rotational speed [ rpm ]
F
sp0
Initial clamping force [ N ]
r
s
Center of gravity radius [ mm ]
F
spz
Cutting force [ N ]
r
sAB
Center of gravity radius of top jaw
m
AB
Mass of one top jaw [ kg ]
s
sp
Clamping force safety factor
m
B
Mass of chuck jaw set [ kg ]
s
z
Safety factor for cutting
M
c
Centrifugal force torque [ kgm ]
Σ
s
Max. Clamping force of the chuck [ KN
1 Newton (N) = 1 kg m/s²
