enginematerialscamshaftcrankshaft-130123030835-phpapp01.pptx

7/24/2019 enginematerialscamshaftcrankshaft-130123030835-phpapp01.pptx

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Materials and technology for automotive

engine

Catania, 06/07/2012, A.Manicone

Material and technologyfor Automotive engine:

brief overview

o The camshaft

o The crankshaft


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engine

The camshaft



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The camshaft -

The valve oeratingmechanism transforms

rotation of thecran!shaft into recirocating

motion in the valves.

The valves rotrude intothe com"ustion cham"er and

are ushed "ac! "y thereactive force of the valve

sring.

#camshaft$ #cran!shaft/2% #camshafthigh& contact ressure is reduced "y the inertia of the valve lifter 'oil is

roviding hydrodynamic lu"rication()% #camshaft low: contact pressure is highestand lu"rication most challenging.


engine



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Machining, dimensionaccuracy, clearance,roughness *riction condition

1. +u"rication2. Contact. *oreign o"-ect+u"ricating oil

condition

ear of sliding ortion

1. ugged surface due toear2. Adhesive ear. *atigue ear. Corrosive ear

*la!ing 'scagliatura(

itting 'corrosione er vaiolatu

ra(

The camshaft -

3t is very imortant to choose an aroriate com"ination of materials.

The tor4ue from the cran!shaft drives the camshaft& it must have hightorsional rigidity.


engineCatania, 06/07/2012, A.Manicone


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The camshaft - 3

Chill hardening cannot "e used here the ga "eteen the cam lo"es is

narro "ecause of the di5culty in using the chiller, so forged camshaftsare used.

Tough martensite is more resistant to itting than the chillmicrostructure.


engineCatania, 06/07/2012, A.Manicone


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The camshaft -

*inishing "oring and grinding

.g.& 8ydroforming

A99M:+3; during hot forging a"ove 1,200 QC. @uring air cooling, thedissolved K com"ines ith car"on and nitrogen to reciitate asvanadium car"ide and nitride at around R00 QC.

the vanadiumcar"ide and nitride ill"e more =nelydisersed.



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The crankshaft -


engine

Manufacturing rocess

Trade%oO&machina"ility%fatigue resistance

9urface roughness

*or lo and medium loaded "earings& a $ 1microinch ma>. J $ 60 microinch ma>.

*or highly loaded "earings& a $ 10 microinchma>. J $ 0 microinch ma>.



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The crankshaft -


engine

Conclusions& Methods to strengthen cran!shafts



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engine

Than!s forattention

Material and technologyfor Automotive engine:

brief overview

enginematerialscamshaftcrankshaft-130123030835-phpapp01.pptx

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