Streamfinishing Process and application OTEC Präzisionsfinish GmbH Dieselstrasse 8-12 75334 Straubenhardt www.otec.de
Content 1. Definition and process description 2. SF vs. DF 3. Setting of the SF-machine 4. Influencing factors 5. Areas and example of application 6. Special machines for special applications 06.11.2013
1. Definition and process description Streamfinishing Streamfinishing is a mass finishing method of DIN 8589. It is also called abrasion finishing, because there is not always a grinding process, but also a lapping and polishing depending on the process. • Short processing times • Easy automation • Up to 5 processing stations • Possibility to charge and discharge in individual processing stations during the continuous processing • Targeted mass finishing with programmable (adjustable) angles 06.11.2013
2. SF vs. DF 06.11.2013
SF – Stream-finishing process DF – Drag-finishing machine • Deburring, edge honing, k-factor • Deburring, edge honing, smoothing and design, the smoothing and polishing is polishing 5 – 10 times faster than in DF because of additional centrifugal forces • up to 5 processing stations, in manual • up to 60 tools per batch, for manual operation up to 5 tools at once, easy to charging, batch operation automate with robot • Targeted/focused localized surface • Low operating effort processing • also suitable for the processing of long tools 06.11.2013
2.1. Comparison of flow forces SF/ DF SF 3/200 120 Flow forces (%) 100 80 60 40 20 0 0 2 4 6 8 10 12 14 Flow speed (m/s) Conventional drag-finishing systems 06.11.2013
2.2. Influence factors Comparison of process forces SF/DF SF DF Motion/Move • Process container rotation • Superposition of three rotations: • Driven workpiece holders (up rotor, holders, driven work piece ment to 8000 rpm) holders • centrifugal force up to 30 G • Immersion depth Pressure • depth of immersion • Increase/ decrease of velocity in • angle of the workpiece holder relation to speed of the • V max: ca. 15 m/s holder/rotor • distance to process container • V max: ca. 2 m/s wall and floor • distance to process container • dry/wet wall and floor • dry/ wet 06.11.2013
3. Setting of the SF-machine 3.1. SF variations SF-manually 06.11.2013
SF 1/30 SF-automatization 06.11.2013
3.2. Process container size and processing stations OTEC‘s stream-finishing machine is available with up to 5 processing stations (PS). The following container sizes are used: - 30 mm (for 1 PS) - 780 mm (from 1 to 2 PS) - 1050 mm (from 1 to 5 PS) - 1400 mm (from 1 to 5 PS) - 2000 mm (from 3 PS) Fast change of the process container without the need for tools. 06.11.2013
3.3. Quantity of lifting units There is either a separate lifting unit per work piece holder or a centered one. One lifting unit per work piece Centered lifting unit holder 06.11.2013
3.4. Standard holder The stream-finishing machines are available with various work piece holders. This includes e.g. a 3-jaw chuck, drill chuck, collets, as well as in the automated case e.g. a gripper. Interface S 8 Drill chuck Gripper Collet Jaw chuck 06.11.2013
The work piece holding system has an integrated clamping system, which is activated by compressed- air. Thus, a work piece can be clamped. Clamping system for work pieces with boreholes 06.11.2013
3.5. Special work piece holder Special equipment such as a high-speed spindle is necessary for certain applications. • Significantly shortening of the processing time because of an additional processing speed • Rotation speed up to 8000 1/min • Work piece – Max. diameter of work piece: 150 mm – Max. length of work piece: 200 mm – Max. weight: 2 kg Areas of application: • Cam shaft • Rotationally symmetrical parts 06.11.2013
3.6 Positioning of the work piece In order to obtain the best possible quality of finish and the shortest processing times, it is often necessary to adjust the position of the work piece in order to align it in the media stream. The following setups are possible: • Work piece immersion angle (Swivel around the X axis): The tool can be immersed in the medium at any angle within the range of 0-35°. It is also possible to flow against the work piece in multiple steps (Pulsing) • Angle of rotation (Swivel around the Y axis): Positioning as close as possible to the drum wall • Six-axis finishing by integrated robot: Moving of the work piece through freely programmable paths during processing 06.11.2013
4. Pulsfinish 3.5.2. Pulsfinish • The work piece is accelerated up to 4000 1/min in less than 1 second. • After reaching 4000 1/min the work piece is being braked immediately and accelerated in the opposite direction (pulsing) • Supported with the inertia of the media and the relative movement between work piece and media hardly reachable areas can also be processed (e.g. intersecting bore holes of hydraulic components, recesses, etc.) • The processing is mainly depending of the density of the media (A higher density of the media results in a higher abrasion) Video SF 3/105 with pulse drive 06.11.2013
Advantages compared to other technologies: • Shorter processing times • Significant lower Rpk-value (e.g. Rpk <0,1µm) Lower coefficient of friction Less abrasion No running-in necessary => significantly less contamination of the oil Up to 2x longer change intervals Higher energy efficiency 06.11.2013
Examples for Pulsinish applications: Processing of cam shaft Rpk ≤ 0,1 µm before processing after processing Juni 2014 18
Possible improvement with Pulsfinish The four working station deburring, grinding, finishing and belt finishing can be replace with one OTEC PULSFINISH working station. Cleaning of the Deburring Turning/ Milling Hardening internal gear Finishing Grinding Belt finishing Hardening OTEC PULSFINISH for deburring, grinding, polishing and finishing (1 station directly after turning/ milling) 06.11.2013
Possible improvements with Pulsfinish of cam shaft gears, etc. - less noise - lower temperature development - No roughness peaks (Rpk below 0,1) No destroying of the lubricant film=> No punctual welding of the friction bodies => Reduction of surface pitting - Less abrasion Less allowance of clearance necessary (Precision parts) No running in necessary No metal removal of running in => significantly cleaner oil - Higher degree of efficiency 02.09.2014 20
5. Influencing factors 5.1. Media The choice of the media determines the machine‘s field of application. They can roughly be divided into 3 classes: 1. Media for deburring/ smoothing (e.g. TZM 2/3, KXMA 24, DS 4/4, KM 6) 2. Media for polishing (e.g. H1/100, H1/400, M3/400) 3. Media for tool preparation (e.g. HSC 1/300) Many granulates can also be used for different tasks. 06.11.2013
5.2. Machine parameters Number of rotation and depth of immersion are crucial to the intensity of the processing. By choosing the rotation direction and alignment of the work piece, certain areas of the work piece can be streamed precisely. Depending on the surface of the work piece, the processing time has to be varied. 5.3. Work piece geometry Different work piece geometries can be processed in the SF-machine. Especially rotationally symmetrical parts work well. 06.11.2013
6. Areas and example of application 6.1. Cutting edge preparation/ Polishing • Removal of micro-defects • Adjustment of the cutting edge (Micro geometry) • Ensuring the quality characteristics of postponed processes Source: TIK - 08 06.11.2013
6.1.1. Advantages Chipping volume Q Not rounded Not rounded Rounded Rounded but droplets but droplets and droplets removed removed not removed Very great improvement of the chipping volume by rounding and polishing (factor >10 compared with untreated tools). 06.11.2013
• Faster chip flow – higher feed rate and cutting speed possible • Less chipping on the cutting edge (lower jaggedness), because of less notching • Better adhesion of the coating Special toolØ 32 0,2 0,18 0,16 Rauhigkeit Ra [µm] 0,14 0,12 unprocessed 0,1 processed 0,08 0,06 0,04 0,02 0 Source: TIK - 08 06.11.2013
6.1.2. Measurement 1. Circular edge 2. Chamfers and angles – Negative chamfer 3. Chamfers and angles – supporting chamfer Source: ALI - 13 06.11.2013
6.2. Further examples of use Deburring of drilling, milling and rotating drill, turn and mill bodies before/ after processing → Process: QZ 1-3W with SC 15 ca. 150 seconds of processing time 06.11.2013
Advantages of polishing of drilling templates • Better chip flow in the flute; this results in a high productivity of the tool • Significantly less corrosion: generally this kind of tools get a surface coating which wears quiet fast • Better appearance for selling 06.11.2013
Task: Polishing of forming tools → Process: M4/300 with ca. 5-10 minutes of processing time 06.11.2013
Task: Deburring/ polishing of worm spindles → Process: KXMA 24 ca. 1 minute of processing time 06.11.2013
Task: Deburring/ polishing of tool holders → Process: H1/400 ca. 5 minutes of processing time 06.11.2013
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