Vehicle Engines - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 139

Table 9.7 Main construction parameters in the self-ignition engine
Construction parameters Physical properties

Combustion chamber The combustion chamber is usually built as an omega hollow. An open, relatively wide design, which lies in the center of the cock, is

the most efficient form [ 27 ]

Cylinder block and head Cylinder head covers are primarily made of plastics for weight reduction. Leak tightness, flat bearing surface, light weight, and

additional ripping lead to additional noise reduction [ 28 , 29 ]. Complete sound enclosure is not necessary since the upper range of
the engine is well shielded from the driving cab with insulation mats and damping [ 30 ]
In mid-sized diesel engines of up to six cylinders with ''in-line'' design, continuous mono cylinder heads which are made of
vermicular graphite cast iron, are predominantly used [ 31 ]. Wet cylinder bushings are made of centrifugal cast iron [ 32 ]

Piston and ring Future pistons, if stress will be less, can be made of aluminum [ 33 ]. Current ring technology consists of two sealing rings and one oil

wiper ring which leads to less friction and to optimal sealing behavior in the cylinder. The rings are made of specially coated steel
and cast iron. Future pistons, if stress will be less, can be made of aluminum [ 34 ]

Crank case The crank case, similar to the cylinder head, is made of vermicular graphite cast iron [ 35 ]. This material makes it possible to reduce

weight by approximately 30% and compensates the weight advantage of aluminum through higher loads and better acoustic
behavior

Crank shaft Currently, crank shafts made of micro-alloyed steel with special hardened brake spaces with high rigidity and shock mounts are used

[ 36 ]. Future multiple mounting of the crank shaft leads to smaller oscillations and thereby to reduced noise emissions

Cock Recently, undivided cocks are using in engine technology [ 37 ]. In the future, depending on development of material technology,

divided cocks will be increasingly applied. On the strength of past experiences, the cock basement will be designed from steel in
order to withstand high ignition pressures

Connecting rod New powder technologies with heat treated, sintered, and pressed light powder elements are introduced. In the long term, carbon fiber

reinforced plastics or light metal will lead to further mass reduction. Predetermined breaking points in new sintered elements will
replace the more expensive divided technology with an integrated connecting rod [ 38 ]

Air and oil containing parts More and more oil and air containing parts are made of glass fiber reinforced plastics [ 39 , 40 ]. Besides this technology, also double-

walled sheet metal oil pans play a substantial role in special vehicles, e. g., in military vehicles

Fuel filter Fuel filters are made of paper and stand perpendicularly. In the future, low pressure downpipes made completely from plastics should

be installed from the tank to the high pressure pump [ 41 ]. Apart from weight reduction, this change should also lead to increased
service life without corrosion

Intake air tube and exhaust
gas pipe

Intake tubes and bend pipes are made of plastics. In order to minimize noise the interior flow is optimized by vibration-free mountings [ 42 ].
Exhaust gas ducts and bend pipes are no longer designed from cast iron but more from sheet metal [ 43 ]. The heat insulation of
neighboring components gain in importance. Auxiliary elements in the exhaust duct are the additional exhaust gas control valve, the
compressor bypass for switching, the turbocharger, and the exhaust gate flap which supports the engine's brake. Closing the exhaust gas