Ngk Insulators, Inc.

Mazda Motor Corporation

Nippon Steel Corporation

Yutaka Ogawa

Takayuki Ogasawara

Toshiyuki Hamanaka

Shunichi Yamada

Shigeru Hanzawa

Seiichi Asami

Tatsuya Kanamaru

Akinori Wakasa

Yoshiaki Hori

Masashi Otaka

Tetuya Morita

Shoji Asai

Motohiro Nakayama

Tsunezo Takeuchi

Katutoshi A Arai

Toshio Takehara

Takashi Hada

A piston for internal combustion engines is disclosed, which includes a piston main body of metallic material, and a ceramic piston head member embedded in the top portion of the piston main body. The piston head member is formed on its peripheral surface with one or more extensions of dovetail section protruding radially outwards and having an axially measured thickness which increases toward the outer end thereof. The piston head member is retained in place with a substantially constant retaining force, even during the operation of the engine.

Piston for internal combustion engines

A structure defining a divided combustion chamber of an internal combustion engine, including an upper ceramic member and a lower ceramic member having a passage which abut on each other at an interface to form therein the divided combustion chamber such that the chamber communicates with a main combustion chamber through a passage formed in the lower ceramic member. The upper and lower ceramics members have cutouts formed respectively in their outer surfaces so as to cooperate to constitute at least one external recess which extends across the interface. An expansion member is fitted in each external recess, and has a larger coefficient of thermal expansion than the upper and lower ceramic members, whereby the expansion member keeps the upper and lower ceramic members spaced apart from each other by a predetermined amount at their interface while the engine is operated.

Structure of divided combustion chamber for internal combustion engine

A precombustion chamber construction of an internal combustion engine includes an upper ceramic body and a lower ceramic body abutting thereagainst to form a precombustion chamber communicating through an injection hole with a main combustion chamber. According to the invention at least a portion of abutting surfaces of the upper and lower ceramic bodies is inclined relative to a plane perpendicular to a longitudinal axis of the precombustion chamber, thereby preventing any relative rotative movement of the upper and lower ceramic bodies even if they are subjected to rotating forces caused by vibrations of the engine or explosion of fuel.

Precombustion chamber construction of internal combustion engine

Herein disclosed is a structure of a divided combustion chamber or a pre-combustion chamber of a Diesel engine of the type, in which the divided combustion chamber is composed of an upper ceramic member having a substantially hemispherical head and a lower ceramic member having an injection port. Either one or both of the upper and lower ceramic members is/are formed with longitudinally and/or transversely extending cut or cuts, slit or slits, and/or groove or grooves at least a portion of the outer surface or surfaces of one or two of those ceramic members. Thus, the resistance of the ceramic members to any rupture is improved so that the divided combustion chamber made of ceramic has highly improved durability.

Structure of divided combustion chamber for diesel engine

Highly gas-tight rotary cordierite heat regenerator is formed of a honeycomb structural body having a porosity of 20-45% and mainly consisting of cordierite, and open pores of the partition walls defining channels of the honeycomb structural body are sealed with a filler thereto, the difference of thermal expansion between the honeycomb structural body and the filler being less than 0.1% at 800.degree. C. The honeycomb structural body is made by preparing fired segments thereof, sealing the open pores of the partition walls with the filler thereof, bonding the segments with a ceramic bonding material, and firing the bonded segments.

Rotary cordierite heat regenerator highly gas-tight and method of

A camshaft having a plurality of cams disposed on a metal shaft in spaced-apart relation with each other in an axial direction of the shaft, comprising at least one ceramic cam portion which is made of a ceramic material, and which includes at least one of the cams. Each of the at least one ceramic cam portion has a pair of joining protrusions which extend from opposite ends thereof in the axial direction of the metal shaft. The camshaft further comprises metallic shaft portions having joining holes which engage the joining protrusions of the ceramic cam portion such that the ceramic cam portion is joined integrally to the metallic shaft portions.

Camshaft for engine

A precombustion chamber construction of an internal combustion engine includes an upper ceramic body, a lower ceramic body abutting against the upper ceramic body to form a precombustion chamber communicating through an injection hole with a main combustion chamber of the internal combustion engine, and a metal ring member fitted on outer circumferences of the upper and lower ceramic bodies. According to the invention, the precombustion chamber construction comprises a first key member provided in the upper ceramic body and the metal ring member in the proximity of its upper end, and a second key member provided in the lower ceramic body and the metal ring member in the proximity of its lower end. In this manner, the upper and lower ceramic bodies are prevented from being rotatively moved even if they are subjected to rotating forces caused by vibrations of the engine or explosions of a fuel. The precombustion chamber construction is easy to handle and superior in gas sealing because an air layer is easily formed between the metal ring member and a cavity of a cylinder head for accommodating the precombustion chamber construction.

A metallic material is electroplated with an iron-zinc alloy with an improved efficiency by using an insoluble anode and an electroplating liquid containing, in addition to necessary amounts of zinc and ferrous ions, 0.01 to 10 g/l of an additive consisting of at least one member selected from oxyalkylene compounds of the formulae (I) to (VIII), ##STR1## and ##STR2## wherein n, n.sup.1 or n.sup.5 =1 to 200,

Process for electroplating a metallic material with an iron-zinc alloy

Herein disclosed is a structure of a divided combustion chamber or a pre-combustion chamber of a Diesel engine of the type, in which the divided combustion chamber is composed of an upper ceramic member having a substantially hemispherical head and a lower ceramic member having an injection port. Either one or both of the upper and lower ceramic members is/are formed with longitudinally and/or transversely extending cut or cuts, slit or slits, and/or groove or grooves at least a portion of the outer surface or surfaces of one or two of those ceramic members. Thus, the resistance of the ceramics members to any rupture is improved so that the divided combustion chamber made of ceramic has highly improved durability.

The disclosed method seals preselected open ends of channels of a ceramic honeycomb structural body with cordierite-forming sealing material batch, and fires the honeycomb structural body with the thus sealed ends, so as to convert the sealing material batch into cordierite.

Method of sealing open ends of ceramic honeycomb structural body

A method of producing a mask to be used for the production of a ceramic filter is disclosed, wherein an ultraviolet ray-transmitting film, which cannot transmit ultraviolet ray at the portion corresponding to the through holes of a porous ceramic honeycomb structural body, into which holes a sealing material is to be injected at the opening end surface of the body, and can transmit ultraviolet ray at the portion corresponding to the through holes of the body, into which holes the sealing material is not to be injected at the opening end surface of the body, is made; the film is arranged on an ultraviolet ray-curable resin; ultraviolet ray is irradiated to the resin through the film; and the ultraviolet ray-uncured resin portion is removed from the resin. The mask matches to the porous honeycomb structural body, and a ceramic filter can be easily produced from the body.

Method of producing a mask to be used for the production of a ceramic

The disclosed method seals preselected open ends of channels of a ceramic honeycomb structural body by attaching a film to that end surface of the honeycomb structural body which is to be selectively sealed while boring holes on the film at positions corresponding to desired open ends of the channels to be sealed, dipping the end surface in a sealing material containing slurry, pressing sealing material mixture body in the desired channels open ends, and then firing the ceramic honeycomb structural body with the sealing materials applied thereto.

The disclosed method and device use a gear rotatably carried by a holder and a movable support board supporting a film-attached ceramic honeycomb body, the gear having pointed teeth disposed at a suitable pitch, and as being thrusted into the body through the film attached to the body the gear is allowed to sway, so that the film is perforated at positions corresponding to selected open ends of throughholes of the body while allowing the gear to sway, so that the throughholes are selectively plugged by pressing sealant therein through the perforated film and the body is rendered into a ceramic honeycomb filter with filtering passages formed of partitions of the thus plugged throughholes.

Method of producing ceramic filter

A two layer-coated steel material having an excellent resistance to corrosion and useful for motor vehicles, has a base coating layer formed on a surface of a steel substrate and comprising zinc or a zinc-based alloy and a surface coating layer formed on the base coating layer and comprising an iron-zinc alloy containing 40% or less of zinc.

Growing community of inventors

Nagoya, Japan

Yutaka Ogawa