Page 18 - january

PRODUCTION AUTOMATION

Control device for waviness of the

machined surface during milling

Milling is one of the most efficient and common methods of metal cutting [1 - 4].
When milling planes with end mills, a tooth removes chips in a relatively short
time in one cutter revolution. Most of the turnover it passes through the air
without cutting. This cools the tooth, which has a positive effect on its durability.
To continue the process of chip formation, the tooth must again cut into the cut
layer, which is accompanied by a blow from its cutting edge. The shock
load leads to a decrease in the durability of the cutter teeth and, in some
cases, to their destruction. A more even milling can be obtained by using
a helical cutter, as is done with end mills. In this case, the cutting edge of
each tooth gradually enters the work piece and then gradually exits it, which
creates a less abrupt change in the cross-sectional area of the cut, a less
abrupt change in cutting force, and, therefore, a quieter operation, ensuring
a cleaner machined surface.
It is proposed [5] that a device for
controlling the waviness of the machined surface
in the process of milling, containing a means
for reading information, was made in the form
of two vibration displacement sensors 1, which are
installed in the horizontal plane of the central zone of
the spindle 2 of the milling machine orthogonally to
each other and are connected by means of a current
collector 3 with the means collection and processing
of information 4 and with a computer 5. In the
same horizontal plane, the device is equipped with an
adjustable counterweight 6, providing high-precision
balancing of the sensors 1 of vibration displacement. The
device also contains a laser sensor 7, mounted on the bed of the
milling machine, and in the central area of the spindle 2 are placed at
a technologically regulated angle to its surface reflective elements 8
in an amount corresponding to the number of teeth of the cutter 9. In
this case, the laser sensor 7 is installed in such a way that it focusing
is directed to the surface of the reflective elements 8 in the process of
milling the work piece 10 and is commutationally connected with the
means 4 for collecting and processing information, and the vibration
displacement sensors 1 are fixed directly on the spindle 2, in its
central zone. The cutter 9 has teeth* (Fig. 2) 11, 12, 13, 14, which Fig. 1. A device for controlling
the waviness of the machined
process the work piece 10. surface during milling.

18 Stanochniy park