10
YOUR GLOBAL CRAFTSMAN STUDIO
Making cylinder processing possiblewithout a semi-finishing
Terasaka (Mitsubishi Motors):
In
automobile parts processing, we
constantly encounter many high
demands. Of particular concern in
our recent challenge was the cost of
machining a high-precision cylinder. The
cutting tool for this one step accounts for
the lion’s share of the cost of tools used
in cylinder block processing. Thus, with
an eye to reducing this cost, it was first
sought to clarify the potential within the
production lines.
Furubayashi (MitsubishiMaterials):
That
was about four years ago, right? After
looking at Mitsubishi Motors’ approach,
we let them know at a Tool Technology
Council meeting that we could help them
make improvements and cut costs.
Goto (Mitsubishi Motors):
Cylinders
currently undergo three boring process
steps,rough,semi-finishingandfinishing.
Our plan was to reduce this to two steps
by alleviating the semi-finishing process.
In order to do so, however, we had to
figure out how to improve rough boring
quality.
Sakuyama (Mitsubishi Materials):
We
proposed a wiper geometry to improve
the surface quality of rough boring and
we were quite confident that this would
be effective when used on a rough boring
tool.
T
erasaka (Mitsubishi Motors):
The wiper
geometry requires significant power; but
because the machine tool that performs
the rough boring application had twice
the power of a general machining centre,
I was confident that it would be powerful
enough to allow us to get the most out of
the wiper geometry.
Furubayashi (Mitsubishi Materials):
After six months of preparation, I was
confident that wewould be able to do this.
I was very excited to know that we would
achieve our goal.
Ideas are connected and shaped
Sakuyama (Mitsubishi Materials):
We
put maximum effort into satisfying all
needs, such as achieving high-quality,
high-efficiency and low cost, shortening
work processes. We examined a wide
range of wiper geometries to find one that
would achieve surface quality equivalent
to semi-finishing boring. The result was a
new insert that applied a double-positive
breaker to reduce cutting resistance. We
also developed a rough boring tool whose
inserts and layout angles were arranged
to achieve a stable process.
Yamada (Mitsubishi Materials):
The
larger the rake angle, the sharper the
insert becomes. However, the sharper
the tool the more breakable the cutting
edge becomes. To prevent breakage and
achieve a rigid high feed cutting action,
we modified the geometry to achieve
more rigidity. Additionally, the original
insert was square and only provided the
use of four corners; but the new insert
is hexagonal, allowing six corners to be
used, thereby lowering the cost.
Goto (Mitsubishi Motors):
For rough
boring, where cutting is more difficult
than the existing process, the set-up
of stock removal and the optimum
machining conditions was the most
difficult. Taking account of the facility’s
capability, we accumulated data on
location accuracy to set the amount of
stock removal. Previously, we had set
processing conditions along the lines
of two-dimensional thinking, of feed
and depth of cut, this time however, we
increased efficiency by simultaneously
optimizing 3 parameters, feed, depth of
cut and speed. During testing we found
the optimum parameters that gave us
higher-quality, higher efficiencies and
lower costs.
Furubayashi (Mitsubishi Materials):
We
processed approximately 20,000 holes
FOCUS ON PERFORMANCE
(Left) Toru Sakuyama: Insert Tool Development Center, Development Department, AdvancedMaterials & Tools Company, Mitsubishi Materials
Machine processing relates directly to
vehicle performance and it has improved
on a daily basis along with automobile
development. The cylinder, the heart
of the engine, plays an important role
in translating explosive power into
movement and the parts that convert
this explosive power to inter-connected
energy requires materials that exhibit
excellent
strength.
High-strength
cylinders are made of difficult to cut
materials and machining these is the
challenge. What type of processing
method is required to create high-quality,
high-performance and low-cost tools?
Mitsubishi Motors and Mitsubishi
Materials are on top of the challenge.
Their solution is the development of next-
generation tools that enable cylinder
machining without a semi-finishing
process. We asked Mr. Goto (Mitsubishi
Motors), Mr. Terasaka (Mitsubishi Motors
Engineering), and Mr. Furubayashi,
Mr. Sakuyama and Mr. Yamada
(Mitsubishi
Materials)
about
the
background of development and
methods.
Part 2 - Development of next-generation tools
through partnerships
Updating processingmethods for
core vehicle parts
