51
Instruction and maintenance manual
ENGLISH
3.3.6 Magnetic force
This manual applies to two types of clamping sys-
tems:
• Systems for milling operations
• Systems for grinding operations.
The circuits of these two types of systems are obvi-
ously different due to the fact that the forces used
differ and are generally higher for milling operations.
The default circuit of systems for milling operations
comprises a reversible magnet, placed below the
flow conductor (pole), and a static magnet that sur-
rounds the pole. When the reversible magnet works
in parallel with the static one, the two forces are
combined.
The default circuit of systems for grinding operations
includes a single magnet that is placed under the
flow conductor.
Consequently, the clamping forces and enabling/
disabling principle are different.
On systems for milling operations, the polarity of the
magnet under the pole is inverted by the solenoid
that surrounds it, while on systems for grinding op-
erations, the magnet is magnetized and demagnet-
ized by the solenoid.
In the circuit of systems for milling operations all
north and south poles are alternated. Consequently,
the crown (or frame) is neutral and is therefore called
“neutral crown”. On systems for grinding operations
(with one magnet, all poles have the same polarity
(north by default) and the magnet is closed by the
frame (which is called “active crown”).
Consequently, the forces involved are significantly
different because the amount of magnetic flow is
clearly much higher in systems for milling opera-
tions.
The magnetic clamping force is represented by
means of the following curves that have been calcu-
lated in the following operating conditions:
• Part to clamp in mild steel
• Thickness suitable to contain the magnetic flow
• Consistent and level contact surface.
Figure D
Figure E
Figure F
L = 1,5 x C;
S = 0,7 x C
L = 2
x
C;
S = 0,5
x
C
L = 4
x
C;
S = 0,25
x
C
