manufacturing methods -...
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Manufacturing Methods
Technology II – Jan Tomíček
Machining operations
• Machined parts
– Rotational – cylindrical (shafts) or disk-like
– Nonrotational(Prismatic) – block-like or plate-like
• Elementary shapes
– Rotational,
– planes,
– contoured.
Examples
Machining operations:
creating a shape
• generating – by the feed trajectory of the tool
• forming – by the geometry of the tool
• combination – of both processes
Machining – generating
5
Machining – forming
6
Machining – combination of forming
and generating
7
Material removal processes
Conventional machining
Turning and related ops.
Drilling and related ops.
Milling and related ops.
Broaching, Shaping,
Other machining ops.
Abrassiveprocesses
Grinding
Other abrasive processes
Non-traditional machining
Mechanical energy processes
Electrochemical machining
Thermal energy processes
Chemical machining
Material forming processes
Classification of manufacturing methods
• Material removal processes
A CUTTING TOOL
• single-point tool (a)
• multiple cutting edge tool (b)
9
CUTTING EDGE• face - rake angle RA α
• flank - relief angle ERA γ
10
Manufacturing Methods
Turning, Milling, Drilling
Turning
Main movement – rotational – workpiece
Feed movement – linear – tool
13
Lathe operations
14
Turning tools - examples
Turning machine - lathe
• Very long history (Egypt, Greece)
• 1300 BC
• Manually powered
• Water, steam
• Transmisions, gearbox
• Electric power, electronic control
16
A lathe – workholding methods
17
PART QUALITY CHARACTERISTICS
The quality of functional surfaces of a part –
4 main parameters (in a part drawing):
• dimension accuracy (a tolerance) –
a grade of fit (marked IT)
• shape accuracy
• relative location parameters
• surface roughness Ra
19
Turning – work time x IT relation
0
50
100
150
200
250
300
350
400
IT 7 IT 8 IT 9 IT 10 IT 11 IT 12
400
280
180
10090
65
%
Work time
20
Turning – work time x Ra relation
0
20
40
60
80
100
120
140
160
180
1.6 3.2 6.3 12.5
170
135
120
100%
Ra
Work time
Work time
21
Turning – tolerances and surface finish
Type of cut IT Ra
roughing 11 - 14 12,5 - 100
finishing 9 - 11 1,6 - 12,5
NC machines finishing 6 – 9 1,6 - 6,3
fine finishing (sintered
carbide)6 – 8 0,4 - 1,6
fine finishing (diamond) 5 – 6 0,2 - 0,8
22
DRILLING
23
Operations related to drilling
Drilling and whatnext?
• Drill(twist)
• Reamer drill – 3-4 twisted flutes and edges
• Reamer – 4-18 linear edges
• Dimensions?
24
Twist drill Reamer drill Reamer
28,5 29,75 30H7
Drilling machine – drill
• Hand drill
• Table drill
• Stand drill
• Radial drill
+CNC machines
26
Drilling – tolerances and surface finish
Process/tool IT Ra
drilling (twist drill) 11 – 13 3,2 –
12,5
rough reaming
(reamer drill)9 – 10 1,6 – 6,3
reaming (reamer) 6 – 8 0,4 – 1,6
counterboring 7 – 10 1,6 – 6,3
27
MILLING• plain (peripheral) milling – the axis of the tool is
parallel to the surface being machined
• face milling – the axis of the cutter is perpendicular to the surface being milled
28
Face milling - examples
►facing ► end milling(a milling head) (an end mill)
End milling
• Variation of tool shapes
• Generative process
Milling machine
31
Milling – tolerances and surface finish
Type of cut IT Ra
roughing 10 – 13 6,3 – 25
finishing 8 – 10 1,6 – 6,3
fine finishing 7 – 8 0,8 – 1,6
Manufacturing Methods
BROACHING
BROACHING• a multiple tooth cutting tool• the forming tool moves linearly relative to the
workpiece in the direction of the tool axis• Movement through or along the part
33
Broaching tool
34
External broaching tool
Broaching process
• on a press – the tool is pushed
• on a broaching machine – the tool is pulled
• Using special machine – stationary broach
36
Broaching machines• vertical ►
• horizontal ▼
37
Broached shapes
• Internal – holes and other round shapes, keyways, profiles, gears
– Need leading hole to place the pilot
• External – faces, T-shape, co-planar surfaces, gears
• Holes calibration – Broach diameter slightly bigger than the hole.
Keyway broaches
Rotary broaching
• internal
Rotary broaching - limitations
Broach lengthSpiraling
Broaching limitions
• Machined volume
– Limited by chip thickness long broach
• Speed
– No wear demands low temperature, forces
• Tool costs
– Expensive production long tool life
Broaching – tolerances and surface finish
Type of cut IT Ra
surface roughing 7 – 9 0,8 – 3,2
surface finishing 5 – 7 0,1 – 0,8
hole roughing 7 – 8 0,8 – 3,2
hole finishing 5 – 7 0,1 – 0,8
44
Video links
• Turninghttps://youtu.be/8EsAxOnzEms
• Millinghttp://www.youtube.com/watch?v=U99asuDT97Ihttp://www.youtube.com/watch?v=RIbdYmmhPDIhttp://www.youtube.com/watch?v=hMK7g_PpCv8http://www.youtube.com/watch?v=J1VtofzVG24http://www.youtube.com/watch?v=r7-eEj_qq5Mhttp://www.youtube.com/watch?v=IPWGV_EGAHwhttp://www.youtube.com/watch?v=9OsNUi_o6C4http://www.youtube.com/watch?v=HfIaISnqHOkhttp://www.youtube.com/watch?v=om6GQKfoS1g
Video links
• Broaching
http://www.youtube.com/watch?v=e26kCaPjX8E
http://www.youtube.com/watch?v=0Qe4ZGlhnhQ
http://www.youtube.com/watch?v=-ksHvyeIb-U
• Rotary
http://www.youtube.com/watch?v=BhvNU2E_x_Y
• Making a broach
http://www.youtube.com/watch?v=WE9ZfnP2SX8
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