Nippondenso Co., Ltd.

Denso Corporation

Hiroshi Furuhashi

Kunihiro Kodama

Syozo Tanida

Toshitaka Saito

Tomio Sugiyama

Hirohiko Tatumoto

Masakazu Murata

Hiroshi Takatsu

Shouzo Tanida

An extruding apparatus for producing a honeycomb structure having cell walls and a skin. The apparatus includes a die (10) and a mask (20). The mask (20) is of an annular shape of an inner diameter (D1) and is located on an annular recess formed by a taper surface (19) and an outlet end surface (18b) of the die. The mask (20) has a top surface (21), which is in contact with an outlet end surface (18b) of the die (10), so that the degree of the opening of feed holes (11a), (11b) and (11c) are controlled by the particular shape of the end surface (21). A change of the mask to the one as shown by a phantom line (30) allows the shape of the top surface to be changed from the one shown by (21) to the one shown by (31), which allows the degree of the opening of the feed holes (11a), (11b) and (11c) to be desirably controlled.

Extruding device for producing honeycomb structure

An extrusion die for forming a honeycomb structure such as a catalyst carrier of a catalytic converter for internal combustion engines is provided. The extrusion die includes material inlet ports and latticed slits. The slits are formed in a die base and have first inner walls leading to an outer surface of the die base and second inner walls leading to the material inlet ports, respectively. Metal-plated layers are formed on the first inner walls of the slits to define outlets of the die and have the width smaller than those of the second inner walls of the slits, respectively. This die structure facilities easy extrusion of the honeycomb structure made up by thin honeycomb walls with a smaller extrusion resistance.

Extrusion die for molding honeycomb structure and manufacturing method

An oxygen sensor has alumina porous layer on a surface of a solid electrolyte to cover electrodes and the alumina porous layer is simultaneously baked with the solid electrolyte. The alumina porous layer has baking contraction percentage which is the same range of the solid electrolyte. Alumina powder which is a starting material of the alumina porous layer includes 0.3 to 0.5 .mu.m of a 50% grain size, 0.4 to 1.1 .mu.m of a 70% grain size, and 0.8 to 4.0 .mu.m of a 90% grain size in a grain size distribution of weight integration frequency and further a specific surface area according to a BET method is approximately 8.5 to 11.0 m.sup.2 /g. It is preferable that the baking contraction percentages of the solid electrolyte and alumina porous layer are approximately 16 to 22%.

Stratified ceramic body, oxygen sensor using the same and fabrication

An oxygen concentration detecting device has a solid electrolyte made of a partially stabilized zirconia on one face of which is formed a measuring electrode exposed to a gas to be measured and on the other face of which a standard electrode exposed to a standard gas. An oxygen concentration detecting device provided with a protecting layer covers the measuring electrode formed on the oxygen concentration detecting device on the face exposed to the gas to be measured, the protecting layer being made of a partially stabilized sintered material of a partially stabilized zirconia material having a specific surface area of not less than 3 m.sup.2 /g and not more than 6.4 m.sup.2 /g to which a divalent or trivalent metal oxide, such as yttria, is added.

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Nagoya, Japan

Hiroshi Furuhashi