Mitsubishi’s latest high speed, vertical 5-axis
milling machine, the new M-VS175-KR, combines extreme accuracy with a unique
control system featuring special software designed to meet the special needs
of the moldmaking and aircraft industries.
Among many benefits, the new machine reduces – and in
many cases totally eliminates – time-consuming benchwork to produce
exceptional finishes. Thus, one of the machine's most important applications
will be in the automotive industry, where increasing manufacturing
productivity – without sacrificing accuracy and quality – is, and will
continue to be, a primary objective for years to come.
The high speed feed control unit developed for this
machine focuses on extreme accuracy. With virtual zero servo error, the
Mitsubishi-FANUC KR-32D high speed feed controller employs a modified,
inverse-transfer function data processing method for advanced accuracy
control. To do this, the feed control function reads the conventional NC
function data in advance of the servo amplifier, calculates the effects of
inertia and servo response on the tool path at the desired feedrate, and
issues new data to compensate for the error. (With conventional feed forward
or tolerance control systems, feedrates must be reduced, and errors cannot be
eliminated.)
The control system features an automatic form follow-up
feed function on which a Mitsubishi patent is pending. The machine feedrate is
optimized so that workpieces with varying form – such as dies and molds –
can be machined without gouges and overshoot drops. Additionally, a smoothing
function is utilized to generate a cubic expression curve from four points.
These functions combine to provide high speed, high accuracy machining at a
cutting feedrate of 8,000 mm/min. (315 ipm) driven by a 25 hp (18.5kW) motor.
Other important elements of the debuted machine includes Mitsubishi’s Z-axis
Automatic Thermal Distortion Compensation system and highly accurate
Mitsubishi precision inductive scales.
The first generation of KR machines incorporating a high
speed feed control pre-processing unit was completed in late 1987. In 1988,
Japan’s Minister of Industries and Trade awarded MHI first prize for
"Excellence in Technological Development." This great honor was
primarily in recognition of the algorithm that enables high speed, high
accuracy machining.
KR-32A, the first generation of KR technology, used a
Mitsubishi high speed feed control pre-processing unit. At that time, 32-bit
processing NC controllers were not available. KR-32B and 32C, the second
generation of this family of machines, were supplied with an MHI-designed and
built CNC. KR-32D, the third and present generation, utilizes an MHI printed
circuit board installed in a FANUC 15MB control cabinet.
Model Shown: MVS14A
The Easy-to-Use, Compact MVS14A Vertical Precision Milling Machine
This compact machine tool has table dimensions
of 39.4" x 78.7" (W x L) with a 118.1" length optional. A
nose-type spindle head allows great workpiece accessibility and heavy duty
milling. And twin synchronous-feed motor drive crossrail (Z-axis) movement
guarantees consistent high machining accuracy and vertical movement
straightness of +0.0006". The MVS14A has impressive accuracies of +0.00032"
positioning, and +0.00016" repeatability.
Mitsubishi's standard of excellence is at work
in the rigid construction of the MVS14A that assures consistent high machining
accuracy regardless of heavy moving loads on the bed. The bed, portal bridge,
and crossrail are welded steel fabrication, and the table and spindle head are
cast iron. The entire machine has a thermally symmetrical configuration to
enhance accuracy; and a heat stabilizing insulator on the rear wall of the
crossrail minimizes the structural displacement due to ambient temperature
change.
For super fast set-up, the MVS14A has a
convenient, centralized control station that employs a Simple Tool Number
Register feature and Program Support Function to eliminate time-consuming
coordinate calculations. The MVS14A also provides operators with the
flexibility of programming successive parts in advance -- while the machine is
milling. Other CNC conveniences are: a single button origin return and a
built-in Self Diagnosis Function that detects any abnormal situations. With a
rapid traverse of 800 ipm, spindle motor output of 24/30 hp, and an ATC time
of 8 seconds, this vertical precision miller is powerful productivity.
Model
Shown: M-VS175
