Technology II

Manufacturing methods Threads Threads Cutting Methods classification: a) according to the object: • external threads cutting • internal threads cutting b) according to the operation: • manual methods • machine methods c) according to the process: • • /rolling

3 Thread

• complex geometry • high precision • geometry and size • surface quality

• different types straight, tapered, tight… Thread types EXTERNAL THREADS CUTTING • machining: – threading on a (engine l., NC lathe) – threading with threading die heads (, machine, threading machine, NC lathe) – – grinding (finishing a thread) • manual cutting – with the threading die • rolling – with the rolling dies: – on a lathe – on a rolling machine

6 Threading on a lathe • the most versatile and fundamentally simple method with the single-point ; • the tool moves longitudinally in relation to the rotation of the workpiece – this determines the lead of the thread

7 A lathe - threading

8 Thread With a turning tool Conventional machine

http://www.lkctraining.co.uk/ Threading on lathe - types

Easy programing, simple Optimized thermal stress For bigger pitch Uniform wear on cutting edge Better chip forming For materials with bad chip formation Deviation eliminates friction Long tool life, equal a small wear Complex CNC programing Thread turning Turning tool CNC lathe

http://www.youtube.com Thread turning Swiss type

With a turning tool

http://www.youtube.com Thread turning CNC lathe

-1 Tool with CBN insert (vc = 100 m.min. )

http://www.misan.cz Threading with the die heads

Link

14 Thread milling cutters • single-form cutter – tilted at the helix angle of the thread, then rotating cutter moved in parallel way with the axis of the simultaneously rotating workpiece • multiple-form cutter – set in parallel with the axis of the workpiece – the thread is completed in one revolution of the workpiece

15 Thread milling

16 Thread milling

• Machine - conventional

• Tool (cutter) Thread milling

• Machine - conventional

• Tool (cutter) CNC thread milling

19 CNC thread milling

- helical interpolation required - combines circular movement in one place (X,Y) - with linear motion perpendicular to the plane (Z)

20 CNC thread milling

21 CNC thread milling

• One or multiple cutting edge • Productivity • Number of

External thread milling on CNC machining center

http://www.misan.cz External thread milling End mill on CNC machining center

http://www.misan.cz External thread milling End mill on CNC machining center

http://www.misan.cz External threads miling

Circular milling

Brush mill usage External threads miling External thread miling

•Okružovacím způsobem

http://www.leistritz.com/ External threads miling

Circular milling

http://www.coromant.sandvik.com/ External threads miling Circular milling, Swiss type lathe

http://www.tornos.ch Threads grinding

35 Threads grinding

• One-profile (Higher pitch values) • Multiprofile (complete) Gr. Wheel (higher productivity, small ptich only) Threads grinding

• One-profile grinding wheel (Higher pitch values) • Multiprofile (complete) Gr. Wheel (higher productivity, small ptich only) Threads grinding – one profile

http://www.luren.com.tw/ Threads grinding – multi profile

http://youtu.be/t1mN76Narhk Radial thread rolling – on a die machine

Methods according the dies function: a) plunge method b) traverse method

40 Thread rolling – on a rolling machine

41 Thread rolling – on a rolling machine Thread rolling - tools Thread rolling – on a die machine

44 Axial thread rolling – on a lathe

45 Thread rolling – on a lathe

46 http://www.fette.com External thread rolling - properties

Turning

Milling

Fine turning

Rolling http://www.fette.com External thread rolling - properties

Thread chaser – full profile cutting tool Manual threading

49 Threading dies • half die → • button die ↓

50 INTERNAL THREADS CUTTING

• on a lathe with inside thread-cutting tool (engine lathe, NC lathe); • with a tap and holder (manually; a lathe, a special threading ); • by milling with a special cutter – similar process to producing external thread; • with a forming tap and holder (manually; a lathe, a special threading machine tool).

51 Threading on a lathe

52 Thread tapping A tap – a tool with flutes creating cutting edges and providing space for chips and Operation: • manual or • at a machine tool

53 Thread tapping

http://www.emugefranken.cz/ Taps set 1. taper tap – a tapered end enters the hole; 60% 2. intermediate tap – proceeds to cut the thread profile; 30% 3. plug tap – finishes the thread. 10%

55 Thread tapping - manual

56 Thread taping První řez

První náběhový zub – břit závitníku

Druhý řez

Druhý náběhový zub závitníku

Třetí řez

Třetí náběhový zub závitníku již s plným profilem závitu Taps set procedure

1) 2) Countersinking 3) Thread – 1st 4) Thread – 2nd 5) Thread - final Thread taping

http://www.emugefranken.cz/ Thread taping

http://www.emugefranken.cz/ Thread tapping

- High cutting forces - Need of very rigid machine and tool - lubrication to minimize wear - Tool with small flute width – overload - Strong demands of precision of pre-drilled holes

- manual work

- broken tap removal? Thread taping

http://www.emugefranken.cz/ Thread taping

http://www.emugefranken.cz/ CNC thread milling

64 CNC thread milling

• Left or Right

property

tap mill

hand (L/R) x OK CNC thread milling

• bottom

property

tap mill

hand (L/R) x OK

bottom x OK CNC thread milling

• force / breakage

property

tap mill

hand (L/R) x OK

bottom x OK

breakage x OK CNC thread milling

• Diameter?

property

tap mill

hand (L/R) x OK

bottom x OK

breakage x OK

Dif. diameter x OK Internal thread milling

http://www.emugefranken.cz/ Internal thread milling

http://www.emugefranken.cz/ Internal thread milling

http://www.emugefranken.cz/ Thread forming

Forming tap has the same shape but it rounded instead of having cuting edges.

Used for less strength materials like Al-alloys, Brass etc.

72 Thread forming P

Product Product

Thread forming tap

Forming tap

Min. predrilled predrilled Min. hole profile

Max. predrilled dia Max.predrilled hole

Nominal thread diameter Nominal thread

Finishing internal thread internal Finishing diameter Finishing nut thread diameter thread nut Finishing

Oil gaps

Structure after cuting Structure after rolling Forming tap profile http://www.emugefranken.cz/ Thread forming

http://www.emugefranken.cz/ Thread control

-Dimensions -Pitch -Equality -Shape -Axis direction -tolerance

http://www.emugefranken.cz/ Thread control Threading – overview of methods

Method name Productivity type

Low (conventional) Cutting Turning Middle(CNC) (subtractive) High(Swiss type lathe) Middle (CNC) Cutting Milling High (Multicontour -mills) (subtractive) Middle (single profile) Cutting Grinding High (Multiprofile) (subtractive) Low – manual Cutting Taping Middle – automated (subtractive) High – reversing heads Rolling (external) High Forming (Additive) Forming (internal) Middle Forming (Additive)

Other – EDM, Ultrasonic variable variable mach,

77 Thread turning conventional https://www.youtube.com/watch?v=9IvWuXjCVbg CNC https://www.youtube.com/watch?v=w5vkc5yevLc (1:20) Swiss lathe https://www.youtube.com/watch?v=mUuz0_mNHDs https://www.youtube.com/watch?v=sYqN90gHOZM Threading 5) https://www.youtube.com/watch?v=JSMWLpx4rS4 Thread milling https://www.youtube.com/watch?v=z7J58jS_i9o single edge https://www.youtube.com/watch?v=SkPdgrjUEhY https://www.youtube.com/watch?v=5BRPv8e53ig Thread grinding https://www.youtube.com/watch?v=ruGfq9tuICA https://www.youtube.com/watch?v=o3TxDxu09zc Thread Rolling https://www.youtube.com/watch?v=bclnb_Cp4sE https://www.youtube.com/watch?v=P89Y4Ht7SCs

Thread rolling on lathe https://www.youtube.com/watch?v=nXJnr5Vn06Y