A steel piston that reduces temperatures in the combustion bowl, thanks to a modified shape and interior cooling chamber, has been launched by German KS Kolbenschmidt.
The improved piston cooling effect noticeably slows the formation of nitrogen oxides, and KS Kolbenschmidt is suggesting that it will serve as another module in meeting Euro 6 engine emissions standards.
As for the detail, there are two forgings in the piston, which are friction-welded to each other, while a cavity for cooling the central crown zone has also been added. This cavity is closed off from the crankcase, allowing lower temperatures on the combustion chamber and oil sides alike.
Additionally, the German firm says the piston improves rigidity and fatigue strength.
These improvements are achieved because low temperatures (for a steel piston) have a favourable effect on the formation of NOx and also reduce blow-by oil particles, caused by the formation of fine aerosols on the hot surfaces. Oil carbon deposits are thus prevented from collecting on the inside of the piston.
KS Kolbenschmidt says the piston, currently in development projects at six commercial vehicle customers, will enter series production from next year (2012).
