Diesel engine cylinder head seal

摘要

A metal sealing ring between cylinder head and liner is made of grey-cast iron having an elasticity modulus in the range 80,000 - 140 N/mm<2>. Typically, in the stress/strain diagram (SIGMA/EPSILON), the ring presents a straight line with rise angle (BETA) and is compared with a conventional steel sealing ring of line (1) and angle (ALPHA). When the cylinder head screws are tightened up, the steel ring is upset by the strain value (EPSILON o) and consequently compressed. Thermal or mechanical load relief moves this strain to (EPSILON 2) as opposed to the grey=cast iron ring relief from change of strain (EPSILON 1 to 3) and so reduces its compression.