Общий каталог Sumitomo 2018 - 2019 - страница 563

Technical Guidance
Basics of Milling
Relation Between Engage Angle and Tool Life
Workpiece feed direction


Relation to cutter position Relation to cutter diameter
Large diameter Small diameter
F F
F2
øD


B
N
N
F3
E E
Engage angle F1 (Small) (Large)
E Insert
Rotation F
F
Engage angle denotes the angle by N
which the full length of the cutting N
edge comes in contact with the E
workpiece, with reference to the feed
E
direction. The larger E is, the shorter
the tool life.


Relation to tool life
Cutting area by


Cutting area by
To change the value of E:


tool life (m3)


tool life (m3)
C50 GG25
1) Increase the cutter size
2) Shift the position of the cutter

Engagement angle Engagement angle

l Relation between the number of simultaneously engaged cutting edges and cutting force:
Cutting


Cutting


Cutting


Cutting


Cutting
force


force


force


force


force
Time Time Time Time Time


0 or 1 edge in Only 1 edge in 1 or 2 edges in 2 edges in contact 2 to 3 edges in
contact contact at any time. contact at any time. contact


To Improve Surface Roughness
j Milling inserts with wiper flat l Surface roughness without wiper flat l Influence of different face angles on surface finish
When all the cutting edges
- Workpiece: 34CrMo4
have wiper flats, a few teeth are Feed per Feed per
- Cutter: DPG 5160 R
one tooth one tooth
intentionally elevated to play the role A (Single tooth)
HC
of a wiper insert.
- vc = 154 m/min
- Insert equipped with straight f t = 0,234 mm/tooth
l Surface roughness with straight wiper flat Feed per Feed per doc = 2 mm
wiper flat one tooth one tooth
(Face angle: Approx 15’ - 1°)
- Insert equipped with curved B - Face angle
wiper flat HF
A : 28’
(Eg. curvature R500) B : 6’

h : Projected value of wiper insert
l Effects of having wiper insert (example)
k Integral wiper insert system Steels : 0,05 mm
Al : 0,03 mm - Workpiece: GG25
common teeth only
Surface roughness


A system to protrude one or two 20
20 - Cutter: DPG 4100 R
inserts (wiper insert) with a smooth 15
C - Insert: SPKN 1203
with


HW
curved edge just a little beyond the 10
- Axial run-out: 0,015 mm
other teeth to wipe the milled surface. h
5
- Radial run-out: 0,04 mm
Feed per one revolution
f : Feed rate per revolution
- (Applies to WGC, RF types etc.) - vc = 105 m/min
Surface roughness


f f
one wiper insert


20 20 - f t = 0,29 mm/tooth
15 (1,45 mm/rev)
D
with


HC 10
C : Only normal teeth
Technical
Guidance


HW 5
D : with 1 wiper insert
Hc : Surface roughness with only normal teeth
Hw : Surface roughness with wiper insert


N8