NANOJIN
Breackthrough2021 AUTUMN

OpticsAutomotive

Reflex Reflector

Head light

Aspheric

Tungstan Carbide

Coaxial lens

Micro texture

Air Spindle

Vibration Cutting

Diamond tool

free-form grinding

Dimand Cutting

Linear motor

LEDNANOJIN 2021 AUTUMN

23NANOJINEDITOR’S NOTE

I

have been in China since the middleof July on a business trip (spite of
COVIDs trouble situation!) for the firsttime in two years and was surprised by
the big change after only two years.
One is that electric vehicles are widelyused and popular. There were different
types of them in town and I often tookthem designed for taxies on a visit.
Next is the face processing to checkthe registration at customer’s gate. Security cameras can recognize our faceand show the registration informationon the screen soon after inputting
them by smartphone. Many high-leveltechnologies having some trouble ormatter that should be improved quickly must be applied, though they already have a stable position in our life.
This means that we are in this situation
because of the strong requirement ofhigh-quality production technology inthe field of automotive, smart-device,
security and medicals. Then, we haveprogressed in research and development both before and during the coronavirus pandemic, to respond above
all for our customers.Now, we would
produce four kinds of issues in thisleaflet, which can play a good role on
customer’s requests.
The first issue is about the direct
machining of cemented carbide. Thisis one of most difficult-to-cut materials and currently machined by grinding and EDM process which is hardly
expected productivity, but originallyhas good characteristics as tool andMold materials such as high abrasion
and thermal resistance and superior
to other kinds materials such as hardened steel and HSS. Therefore, we havestudied the strategy of ductile mode
cutting from the viewpoint of machine
tools characteristics and consideredthat the stable motion is a significant
factor to keep the depth of cut under
the transition region to brittle mode.
UVM consists of an aerostatic bearing spindle and linear motor driven
system which achieves the stable andprecision motion to satisfy the above
cutting situation. As the first casestudy in the leaflet, it is shown a pairof gear molds fitted with only a micro-metered level gap.
The second is about the mirror
finish by using diamond milling. To
apply diamond tool has been an unusual method for mold production
because of difficulties of tool operation and less cost performance though
the demand for the improvement of
shape accuracy and surface roughness
was increasing. We have considered
the reason for the lower performanceof the machine tools, which is less runout of spindle due to the ball-bearing
and non-smooth feeding quality byball-screw driving system. In otherwords, UVM having good run-out ofaerostatic spindle and smooth feedingby linear motor driven system enableeasier to achieve mirror surface withdiamond tool operation. As a secondcase study in the leaflet, it is shownT

he micro channel path shaping by
UVM. Microfluidic devices and microreactors consisting of micro channel
paths are required to be smaller andhigher quality in the field of chemistry
due to quick and accurate inspection
with a small amount of sample.
The third is about making reflector
molds which consist of solid geometry.
Though reflex reflectors which are wellknown as safety goods for vehicles it’s
hard to manufacture by milling or other machining method due to the toolinterfering with cutting tools. Hence,
hand-made polishing and assembly
which means less productivity may
be applied for their fabrication. There
are not only the above cases but manycases of giving up because of the negative reason of the milling process. We
have developed the aerostatic bearing
spindle having the capability of precise
positioning like servo motor drive. The
developed spindle can rotate with highaccuracy as an aerostatic spindle, andmake positioning, furthermore, makecoordinate control motion with otherlinear axes. As a third case study in theleaflet, it is shown making solid geometry consists of arbitrary arrayed reflectors. This is made by milling in a roughcutting process and shaping in generating sharp cavities, coordinating motion
with other linear axes.
Finally, it is about making a moldhaving a large area with mirror finish.
Some machining tool companies produce a line-up of fine accurate machine

tools having aero-static bearing spindle
and linear motor driven system to getmirror surface finish. However, theirability could not be enough to achievea good surface on the whole area of themold needed a long time of machining
because of lack of stability. Our company has long term experience in the
manufacturing of aero-bearing from1970’s and stable structure applied ironmaterials casted in our factory. Thismeans UVM can get high quality andless stripe on the cut surface, whichneeds long time pro-polishing. As acase study in the leaflet, it’s shown thatmaking mold designed with the idea of
VR glass needed a large surface. Though
UVM can generate a mirror surface witha milling process, it was applied with avibration assisted device which enables
the mold to make mirror surface withdiamond tool for steel materials.
The samples for this EMO show
were processed by our potential MZ
generation, who will lead our businessin the future. We strongly believe that
their new ideas with our historical technologies would drive the better products developing and technical to thecustomer even in the rapid change of
Covids Pandemic. Please come to oursite!
Masahiko Fukuta
Expert / Ph.D. (Eng.)SHIBAURA MACHINE CO.,LTD.

NANOJIN 2021 AUTUMN

45NANOJIN

ARTICLEW

CEMENTED CARBIDET E XTS HO S A KATAYA

C

emented carbide is a type ofalloy fabricated by sintering
metal carbide particles withbinder. Mainly WC-Co alloyis industrially used, which iscomposed of tungsten carbide (WC) particles and cobalt (Co) binder. Cemented
carbide has extremely high hardness,bending strength, and rigidity, even under the high temperature condition. For
that reason, it is used as material for cutting tools and press molds that require
wear resistance.
Cemented carbide is difficult to
cut because of its excellent mechanical properties. However, owing to theadvancement of tool technologies, some
cutting tools that can cut cemented carbide were invented. Since cutting is better
than other machining method in quality, efficiency, and flexibility, cutting cemented carbide is receiving attention inrecent years.
As cemented carbide is hard and brittle material, chips are usually formed notby plastic deformation but by brittle fracture. Exceptionally, plastic deformation
occurs when cutting thickness is lower
than 1 µm and cutting edges of tool are
sharp enough. Due to this characteristic,
it is essential for high-precision cemented carbide cutting to use an excellent
machining center and tools.

e focused on linear motor and aerostatic bearing spindle as a structure
to improve motion accuracy of a machining center. Unlike ball screw, linear motor
generates thrust by magnetic force. Dueto this mechanism, it is not affected by
friction or backlash while driving, andit can output very large acceleration instantly. These characteristics are suitablefor following NC commands with high accuracy. As aerostatic bearing is non-contact, it is not affected by wear or vibration
caused by bearing elements. In addition,
error averaging effect of compressed air
absorbs machining errors in the spindle
and housing, resulting in extremely highrotational accuracy. UVM series (Shibaura

FIG.3 NRRO OF THE AEROSTATIC BEARING SPINDLE UVM IS EQUIPPED WITH.

Machine Co., Ltd.) are machining centersthat use the structure. Linear motors areused for three orthogonal axes, and theleast input increment of them is 0.01 µm.
Additionally, they equip the high-precision aerostatic bearing spindle that rotates with non-repetitive run out (NRRO)
of 0.1 µm and total indicator reading (TIR)of about 1 µm up to 60,000 min-1.
To confirm the mechanical responsiveness of linear motors, cemented carbide cutting test was conducted using

FIG.1 AN EXAMPLE OF PRESS MOLDMADE OF CEMENTED CARBIDE.

FIG. 1

FIG. 1

FIG. 2 A SEM OBSERVATION IMAGE OFMICRO FRACTURE.

FIG. 1

FIG.4 THE APPEARANCE OF WORKPIECE AND
SHAPE ERROR PROFILE (DIAMOND COATED).

NANOJIN 2021 AUTUMN

67NANOJINU

VM-700C (H) of the above series.
The machining shape was a concave
spherical surface of 15mm spherical radius and 10mm diameter on a flat surface.
The workpiece was ultrafine-grained cemented carbide with the mean grain sizeof 0.5 µm, and the cutting tools were diamond coated tools. The form accuracy
after the first cutting was 2.28 µmPV, andit was affected by the tool edge profileand the spindle runout. After the second
and third cutting process compensatedthese factors, the form accuracy was improved to 0.69 µmPV. From this result, it
was clarified that the linear motors havethe high mechanical responsiveness thatcan follow the compensation in the order of micrometers.
Then, in order to confirm the effect of the spindle rotational accuracy,
spindle comparison test was performed
using UVM-450C(H) equipped with anaerostatic bearing spindle and a machining center equipped with a general bearing spindle. The test was a simple cutting operation feeding the tool
in one direction at a constant depth ofcut. By this operation, the effect of themechanical responsiveness was minimized and that of the spindle rotational
accuracy stood out. The workpieces were
ultrafine-grained cemented carbide andthe tools were diamond coated tools.
Comparing both machined surfaces atthe cutting depth of 0.1 mm, the one
machined by UVM had the 40% lower
surface roughness, and the 75% lower
variation of the surface roughness thanthe other one machined by the other machining center. Therefore, it can be said

that the high rotational accuracy of theaerostatic bearing spindle contributes tothe stability of the cutting thickness andthe high quality of the machined surface.
Further experiments were carriedout to determine the suitable tool for
cutting cemented carbide. Firstly, cemented carbide was cut using diamondcoated tools and polycrystalline diamond(PCD) tools so as to investigate the machining efficiency. Diamond coated tools
are made by coating base material of cemented carbide with thin diamond film.
On the other hand, PCD tools are madeby forming PCD using electrical dischargemachining, laser machining and so on.
PCD is sintered material made of diamond particles with the mean grain sizeof several micrometers and binder. The
workpieces were same as the previous
ones. To find out the maximum cutting
efficiency of each tool, cemented carbide
was cut under some combination of radial and axial cutting depth. As a resultof trying several cutting condition, thePCD tool achieved seven times higher
machining efficiency than the diamondcoated tool to obtain the same surface
roughness. Furthermore, when machining the concave spherical shape same as
the previous one with the PCD tool, theform accuracy was 0.8 µmPV, which was
almost the same as the form accuracy ofthe shape cut by diamond coated tool.
From the above experiments, it is clarified
that PCD tools have good toughness andwear resistance, and thus are capable ofmachining the same shape accuracy andsurface roughness as diamond coatedtools with higher efficiency.

FIG. 1

FIG. 5 THE APPEARANCE OF WORKPIECE AND SHAPE ERROR PROFILE (PCD).

“”“ IT CA N B E SA ID T H AT T H E H I G H
R OTAT IO N A L A CCUR A CY O F T H E
A ER O STAT IC B E A R IN G SP I N D L E
CO N T R IB UT ES T O T H E STA B I L I T Y O F
T H E CUT T IN G T H ICK N ESS AN D T H E
H IGH QUA L IT Y O F T H E MA C H I N E D
SUR F A CE. ”

NANOJIN 2021 AUTUMN

89NANOJIN

FIG. 5 THE APPEARANCE OF WORKPIECE AND SHAPE ERROR PROFILE (PCD).

FIG. 1

FIG. 2 A SEM OBSERVATION IMAGE OF

FIG. 1

Secondly, in order to compare the qual-

ity of surfaces machined by tools consisting of different material, plane machining test was carried out using diamondcoated tools, PCD tools, and nano polycrystalline diamond (NPD) tools. NPD issimilar material to PCD, but the mean
grain size of sintered diamond particles
is several tens of nanometers and it does
not contain binder. As NPD is purely consisted of diamond particles, it has evenbetter wear resistance than PCD. The
planes were cut with the pick feed of 1
µm, assuming finish machining. To compare the quality of machined surfaces, thedegree of grain pullout was measured
in 0.17×0.13 mm2 area. Grain pullout isa defect that WC particles are removed
from the place deeper than the surface
and thereby micro dimples are formed.
Since micro dimples can be seen as black
points, we regarded those as grain pullout
and calculate the grain pullout ratio per
area. Each grain pullout ratio was 1.70%,
0.28% and 0.02% respectively. When observing the cutting edges of the tools“”

after machining, it was found that thetool with lower grain pullout ratio on machined surface also showed smaller wear.
These machining results confirm that the
cutting tool with higher wear resistancecan keep the shape of the cutting edge
as it was before machining, and thus canmachine the surface with higher quality.
Especially NPD tools showed excellent
results, but it should be noted that they
are relatively expensive compared withdiamond coated tools and PCD tools.
These experiments showed that UVM
series combined with linear motors andan aerostatic bearing spindle are suitablefor cutting cemented carbide with highform accuracy and low surface roughness. In addition, it was found that PCD
tools are suitable for high efficiency andhigh precision machining, and NPD tools
are suitable for finish machining to obtain mirror surface with almost no grain
pullout.

“ TH E SE EX P ERIMENTS SH OWED TH AT UVM SERI ES
CO MB INED WITH L INE A R M OTORS A N D A N A EROSTA TIC BE ARING SP INDL E A RE S UI TA B LE FOR C UT TI N G
CE MEN TED CA RBIDE W I TH H I GH FORM A C C URA C Y A N D
L O W SU RFA CE ROUGHN ESS . ”

FIG. 1

MICRO FRACTURE.

FIG. 6 MACHINED SURFACE OF CEMENTED CARBIDE. GRAIN PULLOUT AREAS ARE PAINTED RED.

NANOJIN 2021 AUTUMN

1011NANOJINC
FROM INSIDER #1

FIT TING GE ARS
T H E U V M-4 5 0 D (H ) EQ UIPPED WIT H A N A ER OSTAT IC
B E A R I N G S P I N DLE A N D A LIN E A R MOT OR C A N MA C H I N E C E ME N T ED C A R BIDE WIT H H IGH PR EC ISION .
T E XT
T O MO YAS U MA KIDA

emented carbide has highabrasion and thermal resistance which are ideal property
for molds, but it also has highmechanical strength and it isdifficult to be machined. The
UVM-450D (H) equipped with
an aerostatic bearing spindle
and a linear motor can machine cemented carbide with high precision.
The fitting gears with a gap of 5 µm
were made to show that the UVM450D(H) achieved high precision machining with cemented carbide. The
error in the gap between the gears is
less than 1 μm.
Cemented carbide has high abrasion and thermal resistance as a molding and forging material for dies, and it
is expected to improve the accuracy ofthe molding and forging production.
However, since cemented carbide isa hard brittle material, it is very difficult to be machined due to its highmechanical strength. Cutting hardbrittle materials requires a machinethat can maintain a constant cutting
thickness. the UVM series equippedwith aerostatic bearing spindles andlinear motors makes that difficult process possible.
The fitting gears were made to showthat cemented carbide can be machined with high precision. A micrometer-order gap is created between thegears to achieve a rattling-free fit.

The fitting gears were made by
UVM-450D(H) of high-precision machining center with an aerostatic bearing spindle and a linear motor. The
tool was a diamond-coated radius end
mill with a diameter of 2 mm and anangular radius of 0.1 mm. The spindle speed was 20,000 min-1, the table feed was 190 mm / min, and thedepth of cut for finishing was 2 μm.
The cemented carbide workpiece was
HRA92.5 and WC particle size 0.5. The
gap between the gears is 5 µm.
Since the UVM-450D (H) is equippedwith a touch probe, form accuracy canbe measured without removing theworkpiece. This system makes easy toconfirm the current value of the form
accuracy and calculate the difference
from the target value.
In addition, The UVM-450D(H)can measure tool contour shapes withtool setter, allowing you to measure
tool shape errors and wear.
The roundness of the outer diameter is less than 1 μm. In addition, theerror in the gap between the gears is
less than 1 μm.
The UVM series can machine various shapes of cemented carbide molds
which is a difficult-to-cut material
with high precision. Therefore, it isexpected that cemented carbide will
be gradually applied in many fields,
and the number of cemented carbide
mold will be increasing .

NANOJIN 2021 AUTUMN

1213NANOJIN

FROM INSIDER #2

MICRO CHANNELTHE SURFACE ROUG HNESS OF THE W ORK I S LES S
THAN RA 5 NM . THE SHAPE ERROR OF THE W ORK ISLESS THAN 1 M I CRON I N BOTH HEI G HT AND W I DT H .
TEXTTOMOYASU MAKID ANANOJIN 2021 AUTUMN

1415NANOJINR

ecently, in the field ofchemistry, as analytical instruments become smaller, demand of microfluidic devices and microreactors that consist of microchannel paths are increasing. The mold was madeby UVM-450D(H) with an aerostatic
bearing spindle and a linear motor.
The surface roughness of the work
is less than Ra 5 nm. The shape errorof the work is less than 1 µm in bothheight and width.
Demand for analysis and mixing
using small amount of samples are
increasing with the aim of speeding
up analysis and reduction of environmental and human load. It meansthat interest in microfluidic devices
to analyze with a small sample andmicroreactors to mix is growing. Bothof them are composed of high precision micro channel.
The width and height of the micro channel is several to several hundred μm. In such a minute region, thesurface roughness have an affect on
the operating characteristics of thefluid. Thus, the molds are required
to have a surface roughness on thenanometer order.
The micro channel mold
was made by UVM-450D(H) of

high-precision machining centerwith an aerostatic bearing spindle
and a linear motor. The used tool
was a single-crystal diamond radius
end mill with a diameter of 0.2 mm
and a corner radius of 0.01 mm. The
spindle speed was 50,000 min-1, thetable feed was 50 mm / min, and thedepth of cut was 2 μm. The used work
material was electroless Ni-P plating.
The UVM-450D(H) can beequipped with a microscope, whichallows the micro channel width tobe measured without removing thework. This system makes easy to confirm the current value of the microchannel width and calculate the difference from the target value.
In addition, The UVM-450D(H)can measure tool contour shapes,
allowing you to measure tool shapeerrors and wear.
The surface roughness of thework is less than Ra 5 nm. The shapeerror of the work is less than 1 µm in
both height and width.
The UVM series can machinecomplicated shapes with high precision, so it can be used for various typeof micro channel mold. Therefore, it
is expected to play an active role in awide range of fields such as analyzers
in the cell field and drug synthesis in
the pharmacy field.

NANOJIN 2021 AUTUMN

16

17NANOJINUFROM INSIDER #3

REFELEX REFLECTORU V M MA C H IN IN G C EN T ER C A N BE
A P P L I E D T O V A R IOUS R EFLEC T OR MOLDS.
F O R E X A MPLE , R EFLEX R EFLEC T OR MOLD IS
C R E AT E D BY 4 -A XIS DIA MON D SH A PER C UT .
T E XTRY OTA HIS A

VM machining center can beapplied to various reflector
molds. Aerostatic bearing
spindle which has a function as a servo axis makes
UVM machining center possible to achieve high-precision multi-axis synchronous
operation. For example ,reflex reflector mold is created by 4-axis diamondshaper cut. Since it is required to havemirror finishing surface and sharp-corner edge, It used to be challenging to
make reflex reflector mold with machining center
Reflex reflector molds for automotive is required to have mirror finishing surface and sharp-corner edge
because high reflection rate and wide
valid reflection area are most important elements for the mold. In a conventional process for reflex reflector
mold making ,each cube which calledarrow shape mold is made one by
one by hand and combine them intoa electrocasting mold. These process
which include reassembling a electrocasting mold by hand for adjustment
takes very long time (90~120days)
and it prevent production lead timeshorter.
We propose a new process tomake reflex reflector using UVM machining center by 4-axis shaper withsingle-crystal diamond tool.
Reflex reflector is created by 4-axis XYZC diamond shaper cut. Indexing
C-axis control makes it possible tofreely design the direction of the reflective surface. Reflex reflector madeby UVM machining center has sharp
corner without fillet R because ofusing sharp edge single-crystal diamond tool .
this process is not only production lead time shorter but also contribute to mold making process withoutmanual work.
In this article, to show how advantageous reflex reflector making
process with UVM machining center,
we made seamless reflex reflector thata length of a side of each corner-cube
is only 0.1mm that never be able to
be made by hand.
As attached image, every single
corner cube has sharp-corner andseamless shape even for complex
shapes that combine multiple pattern shapes.
UVM machining center can beused for milling processing and shaper finishing even the above special
shape. When changing the cutting
processing, the trouble of changeover
can be reduced by using options forautomation (Tool changer, Tool length
measurement device, Touch sensor).
By taking advantage of large tableworking surface, large-sized moldcan be produced the complex shape.
UVM machining centres can provide
an efficient machining process thatcombines high precision machining
operations with high versatility.

NANOJIN 2021 AUTUMN

18

19NANOJIN

FROM INSIDER #4

VR GOGGLESBY USI NG OUR UVM SERI ES AND ULTRASONI C ELLIPTI CAL VI BRATI ON CUT TI NG , I T I S ABLE TO ACHI E VE
ENOUG H ROUG HNESS FOR VR G OG G LES THAT CANN OT
BE ACHI EVED BY PROCESSI NG W I TH END M I LLS .
TEXT
TOH RU SAITONANOJIN 2021 AUTUMN

V

20

21
NANOJINR Goggles that allow you
to easily experience Virtual
Reality have been spreadingin recent years.
Besides the games, contents such as 3D video compatible videos and 360 degree
videos now become enjoyable

at home.
It is also attracting attention in the
education, medical industries. By using
our UVM series and ultrasonic ellipticalvibration cutting, it is able to achieve
enough roughness for VR goggles thatcannot be achieved by processing withend mills.
TO DO: VR goggle molds are required to shorten polishing time andsmaller shape collapse due to the polishing.The work material is STAVAX, a steel
for plastic mold made by Woodenholm
company in Sweden. Hardness is aboutto HRC50. STAVAX is a chromium-alloy
stainless steel cutter with excellent corrosion resistance and abrasion resistance. It is also well known as its finishing
beautiful mirror surface, but it is a metal that is generally considered hard to
cut. Although it is a mirror-like material
when polished, it is generally difficult tomake the finish roughness smaller than
Ra100 nm processing with end mills because of its high processing hardening.
It takes a lot of time to polish, and there
is a problem with shape collapse.
About UVM: Using UVM-700E (5AD),a five-axis machine with a tilt head (A axis) and a rotation table axis (C axis).UVM
is equipped with an aerostatic bearing
spindle and has a maximum speed of
60,000 rotations. A high-speed spindle

with sufficient rigidity and torque inprocessing by end mills. Equipped witha high-resolution scale and linear motor driven with a minimum setting unitof 10 nm, high-precision and smooth
movement can be achieved.
Processing Method: There are twodifferent processing methods.(ultrasonic elliptical vibration and milling).
The side surface of the mold is cutting
by PCD ball end mill. As using the PCD,a processing surface close to polishingis capable even if cutting on the steels.
The TOP surface is cutting with ultrasonic elliptical vibration cutting. By repeating 40,000 vibrations per second,since the cutter wear due to heat canbe suppressed, single crystal diamonds
can be used.
Result: The surface roughness wasmeasured by ZYGO Nexview NX2 and theresult was Ra5~10nm (Rz30~70nm). The
form accuracy was measured by MICURA
5/5/5 (3D measuring instrument) andthe top surface was ±2 μm.
Consideration: The combination ofa 5-axis linear motor machine and anaerostatic bearing spindle allows cutting
to avoid cutter 0 points (the position of
the cutter with zero cutting speed, consistent with the center of the cutter’s
rotation).In addition, by using ultrasonic elliptical vibration cutting, the steel
material can be “cut with single crystal
diamond” and can be finished at Ra10 nm
only by cutting.As a result, the polishingtime can be shortened and the shapeerror can be reduced.These combinations increase the possibility of shortening polishing time or non-polishingprocessing in various molds.

NANOJIN 2021 AUTUMN

22

23
NANOJIN

N

FIELD #1

NS TOOLS TOOL, a Japanese tool manufacturer specializing in the production small diameter end mills,
with nearly 9,000 types of standard
end mills. Our products include MUGEN COATING series, which is widelyused in the cutting field, and MUGENCOATING PREMIUM series, which canbe used for direct machining of hardened steel. We have a wide rangeof products that are highly appreciated by our customers.
In order to meet the common
problem of “how to maintain stable
and high precision even in long-time machining”, we have developed
a series of PCD milling tools thatmake it possible to achieve nano-level mirror finish machining.
This newly developed milling
tool uses “Poly-Crystalline Diamond”
as the tool material, especially the
improved PCDRB, which can process
a wide range of materials, from tempered steel to tungsten carbide, etc.,with perfect mirror finished surface.
This article will focus on the PCDRB series of tools for mirror surface
processing.

P

CDRB has designed a special cutting edge
shape and developed many related processing technologies to achieve nano-levelfinishing surfaces with milling process.
The machining range can be from tempered steel to hardened steel, and even Cemented-carbide can be machined directly.
The picture of the tool shown in Fig.1 isan enlarged view of PCDRB tool tip.
FOR MIRROR FINISH POLY-CRYSTALLINEDIAMOND BALL END MILL SERIES PCDRB (R0.05-R1)

FIG.1 PCDRBNANOJIN 2021 AUTUMN

24

25
NANOJINF

ig.2 shows the stablemirror finish of themachined surface after more than 114 hours offinishing with one PCDRB.
The amount of tool
wear is less than 1μm.

Aquam eiusam faccustibus sit que ditatur apient la quiamus ciumquam venis ea voloribea voluptat.

FIELD #1

NS TOOLTABLE 1 CUTTING CONDITIONS

THE AMOUNTOF TOOL WEARTABLE 2 MEASUREMENT RESULTIS LESS
THAN
0.001MM.
FIG. 2 PCDRB PROCESSING SURFACENANOJIN 2021 AUTUMN

26

27
NANOJIN

FIELD #1

NS TOOLTABLE 3 CUTTING CONDITIONS FOR "COOLANT DIFFERENCE" AND "PICK-FEED
VERIFICATION" AT SEMI-FINISHING

Difference of machined surface quality
by coolant

Water in-soluble
fluid Ra 0.024μ m

SolubleRa 0.071μm

n order to verify the effect of
coolant on mirror surface machining with a PCDRB, comparative machining was performed
using four types of coolant: soluble, emulsion, oil mist, and water in-soluble cutting fluid on
the polyhedral shape (STAVAX52HRC) shown in Fig. 3.
Cutting conditions areshown in Table 3. As shown in
Fig. 3, the surface roughness
value was the smallest with Ra
0.024 μm when using waterin-soluble cutting fluid, and the

Oil mist
Ra 0.040μm

Emulsion
Ra 0.054 μm

REMARKES*1 PF:0.01MM FOR VERIFYING COOLANT DIFFERENCES,
PF:0.01MM&0.03MM FOR PICK FEED VERIFICATION ON SEMI-FINISHING*2 SEMI-FINISH PICK FEED VERIFICATION

FIG. 3 EFFECT OF COOLANT COMPARATIVE VERIFICATION RESULTS (MACHINING AREA: 23 X 10 MM)I

surface roughness value was
the largest with Ra 0.071 μm
when using soluble. It was confirmed that the surface roughness value tended to be larger
when water soluble cutting fluid (soluble and emulsion) wasused.
it is important to select a
coolant that meets the required
accuracy.

NANOJIN 2021 AUTUMN

28

29
NANOJIN

FIELD #1

NS TOOLpf at Semi-finis hing 0.01mm

pf at Semi-finishing 0.03 mm

Effect of Semi-finishing accuracy on the finished surface

FIG. 4 EFFECT OF PRE-MACHINING ACCURACY COMPARATIVE VERIFICATION RESULTS(MACHINING AREA:23×10MM)In order to verify the effect of
Semi-finishing process accuracy,
two types of cutting conditions were
set such as pick feed of 0.03mm and
0.01mm for semi-finishing on a polyhedral shape (STAVAX 52HRC) of thesame shape as in Fig. 3, and the effecton finishing was compared.
The tools used and cutting conditions are shown in Table 2. As shownin Fig. 4, it was found that setting asmaller pick-feed during semi-finishing resulted in a smaller value of finished surface roughness Ra, which
was closer to a mirror surface.
From this result, it can be said
that it is important to set the appropriate semi-finishing accuracy according to the required accuracy.

The mirror finish is also expected to deteriorate. Therefore, it
is important to set the optimum
allowance according to the machining
area.

Setting the allowanceaccording to the cut pointIn order to verify the actual allowance
for shapes that use the area around thetool tip, such as flat areas, two allowancesettings of 0.002mm and 0.005mm wereused.
As shown in Fig. 5, the results
showed that the 0.002mm allowance
was closer to the target value.
The surface that machined at
the 0.005mm stock allowance setting
showed unevenness due to adherence
to the tool, and the tool tip was worn.
Near the tip of the tool, abrasion due toadhered materials and uncut value by
tool deflection are likely to occur, andFIG.5 GROOVE MACHINING CONDITIONS, MACHINING ACCURACY AND TOOL WEARNS TOOL CO.,LTD.

6F. SUMITOMO FUDOSAN OIMACHI EKIMAE BLDG. 1-28-1,OI, SHINAGAWA-KU,TOKYO
140-0014
https://www.ns-tool.com/en/
TEL:+ 81-3-6423-1191 FAX :;81-3-6423-1192

NANOJIN 2021 AUTUMN

30

31NANOJINSHIBAURA JAPANThe Shibaura Machine Group
respects human values. The
Group’s mission is to contributetowards building the foundation for industry through creating an abundance of wealthand helping to improve people’s lives and cultural development.
We started business in1938 as Japan’s first large-scalemachine tools maker. The brandname “Shibaura” has been used

and refined since the establishment to support manufacturing processes of our customers,
mainly in the machine tools industries all over the world.
We would like to introduce
where we are located and how
we are coexisting socially.

NANOJIN 2021 AUTUMN

32

33
NANOJINSHIBAURA JAPANOUR HEADQUARTERS ARE LOCATEDIN TOKYO AND NUMAZU.
NUMAZU WHERE WE ARE IS THE
MAGNIFICENT SCENERY OF MT. FUJI.

NANOJIN 2021 AUTUMN

34

35
NANOJIN

STUDENTS WILL BERESPONSIBLE FORMONOZUKURI IN
THE FUTURE.

SHIBAURAJAPAN
WORK PLACE FOR CASTINGSHIBAURA MACHINE IS HAPPY TO
GET REQUESTS FROM SCHOOLSFOR WORKPLACE EXPERIENCEDAYS FOR THEIR STUDENTS.

THEREFORE,
AS AN ACTIVITYTO PROVIDESTUDENTS WITH AN
EXPERIENCE THATHELPS TO DEVELOPDESIRABLE WORKAND EMPLOYMENTTRAITS, SHIBAURA
MACHINE ACCEPTS
REQUESTS FROMSCHOOLS FORWORKPLACE
EXPERIENCEDAYS FOR THEIRSTUDENTS.

NANOJIN 2021 AUTUMN

36

37NANOJINSHIBAURA JAPANWE CLEAN THE
AREAS AROUNDOUR PLANTS EVERYYEAR IN ORDER TO
CONTRIBUTE TO THE
LOCAL COMMUNITIESAND THEENVIRONMENT AND
RAISE AWARENESS OF
THE IMPORTANCE OF
BEAUTIFICATION.
IN FISCAL
2018, CLEANUPCAMPAIGNS WERECONDUCTEDAT TEN OF OURSITES, INCLUDING
AFFILIATEDCOMPANIES, WITH
THE PARTICIPATION
OF 1,072 PERSONS,INCLUDINGEMPLOYEES AND
THEIR FAMILIES.

31 EMPLOYEES PARTICIPATED INA PLANTING EVENT SPONSOREDBY MT. FUJI NATIONAL TRUST(INCORPORATED NON-PROFITORGANIZATION) AT THE GOTEMBAENTRANCE TO THE MOUNTAIN.
THIS ACTIVITY IS INTENDED
TO PREVENT, BY MEANS OF
GREENING, THE COLLAPSE OF THE
SOUTHEAST FOOT OF MT. FUJI,
WHICH BECAME A VAST GRAVELLAND BECAUSE OF AN ERUPTION
IN THE HOEI ERA.

WE PARTICIPATED
IN A CENTRALPREFECTURE
ILLEGAL DUMPING
ELIMINATIONCAMPAIGN(KANAGAWA
PREFECTURE).
WE CHECKED
ON ABOUT 2KM
SECTION OF THE
RIVERSIDE FROMTHE SAGAMIGAWA
FIELD TO ZAKAEBRIDGE, PICKING UPCOMBUSTIBLE AND
NON-COMBUSTIBLEWASTE WE FOUND
ALONG THE WAY.

WE AS SHIBAURA
MACHINE GROUP
AIM A TRULY ECOFRIENDLY PRODUCTSKEEPING BOTH
ENVIRONMENTAL
AND HUMAN SAFETYAS OUR SUSTAINABLE
DEVELOPMENTGOALS. WE
CONTRIBUTE TO
SOCIETY THROUGH
OUR BUSINESS.

NANOJIN
Breackthrough

SHIBAURA MACHINE CO., LTD. IS A MEMBER OF THE JAPAN MACHINE TOOL BUILDER’S ASSOCIATION.