MACHINING CENTERS
HSM
allows CNC machining centers to compete with a dedicated manufacturing system
such as a transfer line. The machining centers can deliver these benefits:
-
The
reduction
or elimination of
non-cutting time
by minimizing tool-change time
-
Produces more parts
than
machining with a slower spindle and deeper cuts
-
Better surface finish
that can eliminate operations of grinding and hand finishing
-
Minimal warping
of
monolithic (large) parts such as those common in the aerospace industry
-
The
production of single
complex parts
that
replaced sections formerly made up of a number of parts
-
Freedom to change part number
– To set up a dedicated system because of
a design change might require months of downtime while machining centers
can be updated in a matter of days.
-
Fast response to engineering changes
- Any machining center can be equipped to
run multiple part numbers, giving the manufacturer flexibility to respond
to customer needs.
Complex,
high-feed-rate contouring requires high response from the ways and drive motors
of the machine, Fig. 2-1-2. HSM may also affect the choice of machine hardware.
How well the machine manages heat may be a factor. And the freedom to take
lighter cuts might permit a different method of contouring.
Fig. 2-1-2
High-feed rate contouring
requires high responsive ways and drive motors. (Modern Machine Shop)
MACHINE TOOL WAY SYSTEMS
The
way system is the part of the machine tool that holds linear motion on track in
each axis. There are two basic types:
1.
Box or hardened ground ways
usually found on conventional machines consist
of a box-shaped stationary way that mates with a slide. A thin film of oil is
pumped between them to keep the slide moving, Fig. 2-1-3A.
Fig. 2-1-3A
Conventional machine tools are
usually equipped with box ways. (Fadal Machining Centers)
2.
Linear guides
found on newer machining centers have a linear
bearing system that rolls along a guide way. This guide way is usually shaped
in a way that helps the bearing grip it, Fig. 2-1-3B. Most machining centers
designed for HSM use linear guides.
Fig. 2-1-3B
Linear guides are found on newer
machining centers. (Fadal Machining Centers)