Ko Large Bore Pistons

7/27/2019 Ko Large Bore Pistons

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Large Bore Pistons

Kolbenschmidt Pierburg Group


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KS Kolbenschmidt GmbH develops, produces and sells pis-

tons or combustion engines (or passenger cars, commer-

cial vehicles, ships, stationary engines) as well as or piston

compressors.

Thanks to a global network o production and sales units

stretching rom Shanghai to So Paulo, were never ar rom

our customers, assuring ast, exible service and support.

At nine strategically sited locations, KS Kolbenschmidts

5,480-strong workorce develops, produces and distributes

engine pistons and reciprocating compressors in Europe,

North America, South America and Asia. We have long since

counted the worlds major engine manuacturers among our

core customers, all o whom come to us with highest expec-

tations o quality.

KS Kolbenschmidt with its range o products extends rom

pistons or proessional chainsaws and heavy-duty machin-

ery through to applications or passenger vehicles, trucks,

ships, locomotives and stationary equipment. Moreover, we

Research and Development

Product development at KS Kolbenschmidt ranges rom basic

research, material and technology development to the adap-

tion o these basic developments to the customers individual

requirements.

Large bore pistons, due to the high cost o actual testing in

an engine, demand and place special priority to the design

concept. Modern analytical methods and systems are em-

ployed, e.g. CAD (2D and 3D), 3D fnite element analysis and

high-speed photography in shaker test investigations.

R&D Highlights Large Pistons

3-piece Articulated Pistons

Steel Skirts or Composite Pistons

Steel Monobloc Pistons

Fibre-reinorced Aluminum Pistons

Low-riction Pistons

KS KOLBENSCHMIDT GMBHPartner of the Motor Vehicle and Engine Industry

cover the entire diameter spectrum rom 20 to 640 mm.

Our pistons, made o aluminum, spheroidal graphite iron

or steel, as well as combinations o these materials, enable

us to meet the complete range o perormance requirements

levied by our customers.

KS Kolbenschmidt is doing its utmost to achieve the goal o

ever reduced uel consumption, reduced emission o pollut-

ants and ever-lower weight, making us the natural source or

advanced piston systems when it comes to direct injection

gasoline engines, high-perormance diesel and lightweight

applications or modules.

Whether or innovative piston designs and the latest layout

calculations, optimised production calculations or the just-

in-time delivery o high-precision pistons KS Kolbenschmidt

customers worldwide appreciate our ast service and strin-

gent standards o quality.

Production EngineeringThe Corner-stone to Success

Machining o pistons at KS Kolbenschmidt is done using

state-o-the-art NC and CNC equipment. This ensures a maxi-

mum o machining accuracy, production reliability, repro-

ducibility and economic efciency.

QualityOur Biggest Asset

The high quality standards maintained by KS Kolbenschmidts

large bore pistons is ensured by in-production quality sys-

tems and fnal inspections employing sophisticated inspec-

tion equipment as the 3-coordinate measurement units,

isotope-, X-ray-equipment, ultrasonic testing equipment or

non-destructive testing.


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Aluminum Pistons Aluminum Pistons with Fibre Reinforcement

Electron-beam-welded pistons are

usually made out o a lower part

(skirt), which is orged and an up-

per part which is cast and has a

single or a double ring carrier and

i necessary it has a cooling gal-

lery. The material is the well known

KS 1275 alloy. I there is a special

request rom an engine builder or

the design o the combustion bowl

like a reentrant design, KS Kolbenschmidt can implement a

fbre reinorced bowl rim. This fbre reinorced ring is squeeze

cast under high pressure. The fbre body itsel consists o

20 % AI2 O3 fbres and gives together with the squeeze cast

aluminum a high strength or the high loaded bowl rim area.

The fbre reinorced ring is connected to the upper part o the

pistons by electron beam welding too.

One piece aluminum pistons made o KS 1275 eutectic AlSi

alloy, are employed in diameters ranging rom 160 to approx-

imately 450 mm. Pistons with diameters exceeding 200 mm

are manuactured employing directionally chilled fne g rain

castings, with cast-in ring carriers o austenitic grey iron and

cooling coils.

Aluminum pistons in the 160 to 200 mm diameter range are

either o one-piece permanent mold castings, in some cases

with either casting saltcore cooling gallery and single or dou-

ble ring carrier, or electron-beam-welded pistons where a

orged skirt is welded to an aluminum casting containing

the salt core cooling gallery and the ring carrier by means o

electron beam welding.


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NCI Monobloc Pistons Articulated Pistons

Monobloc pistons made o GGG 70

were introduced to the market by

KS Kolbenschmidt in 1973. Since

this time they have undergone con-

stant development. High strength

and low thermal expansion o the

material used allow the manuac-

turing o thin-wall pistons and the

introduction o low running clear-

ances. Monobloc pistons in diame-

ters rom 170 to 350 mm diameters

represent an economically attractive alternative to compos-

ite pistons in account o their simple design (no connecting

elements, integrated cooling spaces) and their proven reli-

ability with heavy uel operation.

The KS Kolbenschmidt design or an articulated large bore

piston is a three piece articulated piston or a composite artic-

ulated piston. The orged steel crown (material: 42 CrMo 4V)

is bolted together with a cast pin boss (material: GGG 70).

The skirt is made out o orged aluminum (KS 1275) and it is

connected to the pin boss by the piston pin. The advantages

o this design are basically the low weight by achieving high

perormance data and it is possible to achieve a relatively

low compression height.


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Composite Pistons with

Aluminum-Skirt

Composite Pistons with NCI-Skirt

Composite pistons with a orged

crown made o 42 CrMo 4 steel

and a orged aluminum skirt made

o KS 1275 were developped in

the 1960s with the objective o

separating thermal and mechani-

cal loads by employing the ideal

materials or the crown and the

skirt respectively, with urther ad-

vantages such as unlimited heavy

uel suitability and repair easibil-

ity. This design has established it-

sel over the entire diameter range,

i.e. rom 160 to 620 mm, and is up to now the standard pis-

ton type in medium speed engines. Future developments,

however, require dierent designs and consequently St/Al

pistons will decrease due to their limitation in peak fring

pressure.

Composite pistons with a conventional designed steel crown

section and NCI-skirts are used wherever the peak fring pres-

sure exceeds the limits o aluminum skirts, i.e. pressures o

approx. 18.0 to 21.0 MPa. Composite pistons have been de-

veloped by KS Kolbenschmidt GmbH or even higher fring

pressures, which utilize a bore-cooled, rigid steel crown and

a correspondingly dimensioned NCI 70-skirt.


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Composite Pistons with Steel-Skirt Steel Monobloc Pistons

For uture developments and or s ome special applications

today KS Kolbenschmidt is using a composite piston with a

steel skirt. The crown and the skirt are made out o orged

steel (42 CrMo 4V). This design can then be used or very

high peak fring pressures in the range o 21 to 25 MPa. The

advantage o this design is the relatively low weight in com-

parison to NCI due to the act, that you can use a reduced

wall thickness. The low weight steel skirt and the orged

steel crown (standard or bore cooled) are bolted together.

The high strength o the skirt material gives some space or

even higher peak fring pressures and urther developments

o this piston type.

The steel monobloc piston (material: 42 CrMo 4V) is today

mainly used in the diameter range o 160 to 210 mm. This

design combines the advantages o a monobloc piston with

the advantages o orged steel or the whole piston. The

orged steel crown and the orged steel skirt are connected

by electron beam welding or riction welding. This means you

can reduce the piston height to an absolute minimum fg-

ure (compression height). The steel monobloc with a closed

cooling gallery is prepared or high thermal and mechanical

load with relatively low weight.


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Subjects to alterations. Printed in Germany. A|IX|h

KS Kolbenschmidt GmbH Karl-Schmidt-Strae 1 Neckarsulm GERMANY

Tel. + 1 -0 Fax + 1 - www.kspg.com

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Ko Large Bore Pistons