Description of the Lost Foam Casting process and explanation of what makes the Lost Foam Casting Process preferable to other forms of casting techniques.
47. CERMAK ENGINEERING PFAHLER STR.21, 65 193 WIESBADEN, TEL.+49 611-1509 9495 E-Mail : kcermak@aol.com PLEASE ENQUIRE ABOUT OUR PRESENTATION PART 2 “ HOW IS LOST FOAM CONTROLLABLE? ”
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The dimensions of the foam part determine the required casting tolerances. There is no tooling wear Just about no cleaning or fettelling is required because there are no fins or parting lines
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Last But not least is the Enviromental ADVANTAGES to be mentioned . Here is one essential comparism figure. Lost Foam Chemically Bonded Sand Green Sand 0,3 % 5% 12% organics by weight of iron casting poured 3 kg 50kg 120kg per poured Ton of poured Iron IT is simply less stuff and it is easyer to collect too .
AS CAST FEATURES High pressure oil line to hydraulic lifters High pressure oil line to cam bearings Gravity oil return lines Combustion chambers Integral lifter pedestal and cam journal Cooling water flow
AS-CAST FEATURES Alternator bracket Oil filter mount High pressure main oil line (4.2m drilling, 100 cm3 Al) Bearing oil feed lines Gravity oil return lines Water pump housing Thermostat housing Bore deck gasket flange - the machining centers that would otherwise have been required would have cost 2/3 of the foundry investment
Die-casting with salt cores would have required 3 parts 1-2 mio $ saved on machining centers 30% lighter
9 Semi-permanet Mould Castings replaced by 2 Lost Foam Castings.Optimal use of this technology .
15 % lighter - 7 holes as cast - 2 side oil connections as cast - Through holes without draft - Wall thickness reduced to 4mm 45% reduced machining cost from: - Elimination of 5 plugs - Flange holes cast ready to tap - No machining of internal oil and water channels No Heat treat for core removal Tested at 120° hot Öl at 15 bar ü Summe = 28% Cost reduction and reduction of Leakage potemtials. No back up for this casting some where else .
NO DESIGN MODIFICATION !! Only advantage is the process capability .
18 changes accepted -Weight reduction : Exhaust ports Spark plug area Intake ports Oil distribution channel Central part of the water jacket Ruduction of the external profile Reduction of the fins in the oil distribution Wall thk. 4mm: Machining tol 1.5mm - Increase of the spark plug opening to increase cooling - Improved stabilising fins - Material under the cam supports reduced - In total cost saving of 28% and reduced leakage due to elimination of plugs
Holes and air passage for secondary air as cast - ca. 4mm diam.! Injector holes have a min. machining stock Elimination of 3 plugs Even wall thickness 3mm with min. 2.75 mm 30 % cost reduction and 15% weight reduction !!!!
Even wall thickness
6 mm Wall thickness Increased stability Reduced machining stock
Excellent Example 50% - cost reduction, even wall thickness
Cast-in heating coil All holes No machining
6 mm Wall thickness Stiffer Reduced machining stock Cast-in bronze bushing - many manufacturing steps eliminated
All holes Hose nipple as cast Seal groove cast to size Separator plate Resonance pipe
NO TEAM APPROCHE
Functions tolerances = Machining tolerances Existing machining center ---> no investment advantage No machining advantage Small tooling saving Separation distance of +/- 0.15 mm not achieved To compare with CNC machining center is pointless
No changes or adaptations to the L/F - process were allowed Not demoldable Not glueable
Walk thickness too small < 3mm Roundness tolerance not achieved Concentricity not achieved
Hollow main and pin journals As-cast, uncheeked, untopped counterweight Ignition point control cast to size 45% - cost saving 1.5 kg lighter 2.58 kg reduced swarf
Uniform walls, part symetrically round As-cast speedometer teeth Lubrication groove No chaplets - no structural faults
Totale cost saving 10 % 95% reduction in machining Holes have a tolerance of +/- 0.4 mm , Separation dimentions 0.8 und 1.6 mm Flange parallelity 0.8 mm 10 % lighter
Parallelity of the guides. No demold draft necessary
Prototype in sand casting weighed 12.1 kg Fins 3 mm x 80 high !! !!!Critical for bulid up of “Lederburite” in the to of the fins- Anealing required.
Experiment - shrink-fit onto “ sheet packet” did not fit Design not mature GGG without white structure in the rib tips!!! Wall thickness 3mm
left 1 rotor, right 2 - 4 parts stamped and welded - also the rotor performance per cc could be increased An alloy with better magnetic properties could be used - such an alloy is not suitable for the stamping/welding route.
Casting weight reduction of up to 40% Quicker machining Location holes cast to size Cooling fins thinner and closer - improved cooling - lower energy consumption
Improved cooling Finer fins
Cost saving of 20 %. 5 holes with 0° draft Thread Lead chamfer All Bolt holes as cast. 10 % lighter
Redesigned part - Outside Geometrie untouched, the Wter Jacket narrower -- the “Gas Throghput” larger. - Performance increased by 10 bis 15 %. - Leakage caused by chaplet was eliminated -All holes cast to size - No heat-treatment necessary - solidification more uniform Surface slower, inside faster - ideal
Lower total cost Clear improvement of optical appearance !!!! As Cast Drai chanals / holes 10 % lighter Improved water flow Hose nipples cast to size
Flange Faxes are parallel- NO Draft As Cast holes Undercut for O-Ring retention as cast Guaiding for Slider as cast O-Ring grove as cast NO MACHINING Saving of 35 %
coservative , old Designed Head for Power Generator Driving factor - Replacement of old “out of Shape” foundry- Process capability to be inprooved. But , relative design freedom - especially inside of the casting RESULTS: Lighter 8% - due less draft or No draft 16 Cooling water holes 8 Oil - return lines as cast 4 direct cooling water supply ports 4 Injection holes
Cooling Pins / Fins not mouldable with Green Sand nor with any other Sand moulding method.
70 % of Cost are born due deburing / cleaning of casting Yield enormous!
to your left is L/F Castings, right the old - multiply parts component. Savings Turning Cutting Bending Grinding Welding compared to pour and finish!!
As Cast cooling chanal - originaly velded on. Ra 6,3 - 12,5 achievable Holes and slots from 4 mm Machining stock 1 - 2 mm Very often NO RISERS !
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