Search Results

A cylinder pressure sensor using a piezoelectric element which has high temperature resistance has been developed. The thickness shear mode in the element was utilized so as to diminish the pyroelectric effect. A ceramic pressure transfer pin inserted between the piezoelectric element and the stainless steel diaphragm is capable of shielding the heat from the diaphragm of high temperatures and also of insulating electrically the element from the housing. The characteristics of our sensor were evaluated by means of a hydraulic pressure generator and test engine. Our sensor outputs showed good matching with the reference pressure sensor outputs.

High temperature capability filter traps have typically been employed for the collection of the solid particulates from the diesel exhaust (1,2,3,4,5,6)*. Our efforts have concentrated on trying to apply the sintered textile structure of ceramic fibers as filtering elements of diesel particulate traps, Mullite fiber ceramics is prepared by sintering as composites of Mullite fibers and silica-alumina clay. Mullite fiber ceramics has a porosity of up to 80%. Generally the higher porosity trap element would exhibit lower filtration efficiency (7). However, diesel particulate traps composed of the porous Mullite fiber ceramics show significantly high filtration efficiency of around 75%. Mullite has a higher working temperature than Cordierite, but its relatively larger thermal expansion coefficient (5.0×10−6/°C) results in poor thermal shock resistivity.