A very warm welcome (Arial, 24-point bold font) Discover what's under the surface (Arial, 20-point bold font in italics)

Transcription

1 A very warm welcome (Arial, 24-point bold font) Discover what's under the surface (Arial, 20-point bold font in italics)

2 HORN Technology Days 2015 Longitudinal turning Flexibly producing complex turned parts Speaker: Alan Whalley 2

3 Shoulder fracture 3

4 Overview What does "complex" mean? Machine, material and tool Machining strategies Tool solutions Summary 4

5 Complexity conserves resources efficient Shape and position, surface, dimensions economical Material Machine Tools user-friendly fast low-energy precise Complexity generally refers to a property that a system or model has whereby its overall behaviour cannot be described in simple terms, even if all the information about its individual components and how they interact is available. 5

6 Machine and guide sleeve Guide sleeve: Made from spring steel Ideally with wired-in carbide Single or double cone (better guidance) During transverse machining: clamping an advantage Guide sleeve Swiss principle Spindle Axial infeed: Multiple parts per stroke One part per stroke One part per multiple strokes Guide sleeve Offenbacher principle Spindle 6

7 Material Precision is determined by: Accuracy of the bar material Surface of the bar material Type of bar material Guide sleeve Headstock + Z axis Rotation synchronous with main spindle Rarely (outdated): stationary Guide sleeve Tools + X axis Achievable accuracy levels: Basic tolerance level that is better than the guide sleeve Example: IT8 on the guide sleeve IT7 on the tool 7

8 Machine structure Advanced machine concepts; turret solution and tool unit Source: Traub / TORNOS 8

9 Machining small parts Plunge cuts from cutting width of 0.5 mm Cylindrical areas Profile machining Form plunge cuts Thread machining Milling 9

10 Requirements Accessibility Cramped space Internal cooling? Strategic machining workflow Usually small components Low cutting pressure, as components are usually thinwalled Tools Counter spindle requires back end machining 10

11 Insert clamping Clamping inserts even with limited available space 11

12 Cutting pressure Sharp tools cutting pressure! Thin PVD layers Feed rate 0.01 mm or less Perfect cutting edges for glossy surfaces 12

13 Surfaces and precision S274 Versions specifically for extremely small parts Minimum cutting edge chipping Glossy components even at minimum feed rates x

14 Component Parting off Turning to diameter Thread Bore machining 14

15 Supermini One tool 1500 standard applications With integrated cooling One holder for left or right Patented toolholders for limited available space 15

16 S274 insert Developed for long automatic lathes Two-edged Precision-ground Tip: 3 chamfer to prevent burring One holder, many applications Directly screwed on 16

17 Thread whirling Advantages (+) High cutting rates / low profiles / steep flanks Low thread / no bending Short chips Multi-threads too Tip: Climb produces better surfaces Disadvantages (-) Segmented surfaces Driven unit Whirling head 17

18 Implant screws Workpiece material: Titanium grade 5; ; Ti6Al4V Thread whirling with M302; rotation ratio: 1:2.6 Core special thread - ø 2 mm; P = 0.75 mm Cutting speed.: v c = 120 m/min Number of teeth: Z = 5 Feed rate/tooth: f Z = 0.07 mm Chip thickness: h m = 0.02 mm Cutting depth: a p = 1.5 mm Cooling/lubrication: Oil Tool life in pieces: 1100 components Tool life: 35 m 18

19 BMBF project GeWinDe Funded by: 19

20 Cutting simulation Material: Ti6Al4V; various chipping angles 20

21 System S224 with internal cooling Normally used as stop Groove depth up to 18 mm Holder with or without internal cooling Clamping inserts with or without internal cooling Grooving, longitudinal turning, parting off, profiling Flow of cooling lubricant channel in insert optimised 21

22 Tool solutions Machine-specific tool solutions Tailored to the space available in each case With or without coolant supply 22

23 Tornos CT20 and demo part Source: TORNOS 23

24 Summary Complex parts require knowledge of material, machine and tools Machining strategies and tools that are suitable for requirements must be used; special machining processes like thread whirling are available Tool systems tailored to requirements or machine type in the case of longitudinal turning 24