Abstract: A spark plug having an improved radio noise suppression effect and durability of the resistor. The resistor of the spark plug is made of a sintered material comprising by weight, 0.9-3.0% of one of TiN, TiC, WC, TiB.sub.2, ZrC, HfC, SiC, TaC, MoSi.sub.2 and mixtures thereof, 9-40% of fine glass powder having a larger grain size than that of said conductive material, not more than 20% of magnetic substance, and 60-90% of coarse glass powder having a larger grain size than that of the fine glass powder. The composition is free of elemental carbon.

Abstract: A distributor for an internal combustion engine, wherein a plurality of fixed electrodes which are respectively connected to a plurality of sparking plugs of an internal combustion engines, a rotating electrode rotatable in synchronism with a crank shaft of the internal combustion engine thereby forming sequentially a narrow gap with each of the fixed electrodes, and at least either the fixed electrodes or the rotatable electrode are made of such a ceramic that has the function of a varistor. Thereby the distributor is capable of suppressing noise current caused by spark discharge which is made between the rotating electrode and each of the fixed electrodes.

Abstract: An ignition distributor for use in internal combustion engines has a noise preventive function capable of suppressing the generation of radiowave noises due to the spark discharge produced between a rotary electrode and stationary electrodes disposed on the side of the rotational circumference thereof opposing thereto. The ignition distributor has stationary electrodes and a rotary electrode, in which each of the plurality of stationary electrodes or rotary electrode has a main body made of a sintering product composed of powdery zinc oxide and powdery ferrite and a surface layer mainly composed of ferrite integrally formed to the surface portion of the main body.

Abstract: A sheathed heater comprising a metallic sheath, such as a stainless steel sheath, an electric heating element disposed within the sheath so that an electric current can be supplied thereto, and a filling material filled in the sheath for insulating the heating element from the sheath and the coils of the heating element from each other. Aluminum nitride powder is used as the filling material to prevent oxidation of the heating element by the oxygen discharged from the filling material.

Abstract: A distributor having electrodes made of a sintered body composed of a composite material such that the distributor can suppress radio noises to thereby prevent electric interference. The material for the electrodes, the sintered body, is composed of 45-90 mol % of zinc oxide and 55-10 mol % of ferrite, which can suppress radio noises generated between the electrodes due to spark discharging. At the same time, the energy loss within such composite material is small and consumption of electrode can be restrained. Electrode durability is further improved by including bismuth oxide, manganese oxide and cobalt oxide in the electrode material. An ignition plug and electric discharge machine can also advantageously use the electrodes composed of such materials.

Abstract: A ceramic heater of the present invention comprises a sintered heating element bonded to a supporting substrate or a sintered element alone. A sintered body comprises the heating element is mainly composed of silicon nitride with such sintering agents as yttrium oxide to be superior in strength, thermal shock resistance and thermal resistance. The sintered body also includes 10-80 mol % of titanium carbide, titanium nitride or a mixture thereof which are electrically conductive ceramics so that the specific electrical resistance can be controlled.A method for producing a ceramic heater of the present invention consists of the first process in which a powdery mixture is prepared by mixing powders which are made to have structures of a solid solution by previous calcination of silicon nitride and a sintering agent and powders of conductive ceramics which comprise either or both of titanium carbide and titanium nitride, and the second process in which such powdery mixture is formed and sintered by heating.

Abstract: A ceramic heater having a heating element of a sintered mixture comprising alumina, titanium nitride and titanium carbide, is discribed. The heating element has a good oxidation resistance, and a relatively high temperature coefficient of resistance. The larger composition of titanium nitride acts to increase the temperature coefficient of resistance. The larger composition of alumina acts to prevent oxidation increase and to improve the sintering. The adequate composition of each ingredients can result in a suitable heating element for a ceramic heater.

Abstract: In an exhaust gas cleaning apparatus a ceramic heating resistor has a lattice-shaped exhaust gas passage and is formed by extrusion. The ceramic heating resistor is fixed closely to the upper stream side of a filter which catches particulates contained in exhaust gas. This heating resistor is divided into a plurality of sections so that heating current is successively supplied to the divided sections.

Abstract: A ceramic heating element is held in a metal housing to be mounted on an internal combustion engine, so that the heating element is operated as a glow plug for igniting an air-fuel mixture. The ceramic heating element is formed of an electrode section housed in the housing and a heat generating section extending out of the housing, whereby the heat generating section is exposed to the mixture in an engine cylinder. The electrode and heat generating sections are divided into two portions, respectively, and both forward ends of divided heat generating portions are connected with each other, so that electric current flows from one of the electrode portions through the divided heat generating portions to the other electrode portion.

Abstract: A ceramic heater having a heating element of a sintered mixture comprising alumina and titanium nitride and/or titanium carbide. The heating element has a specific resistance in a range from 10.sup.-4 to several .OMEGA.cm. The ceramic heater may have supporting substrates of insulating materials with which the heating element is covered. The ceramic heater can be used at a temperature above 1000.degree. C.

Abstract: A method of manufacturing a porous ceramic body useful for a catalyst carrier or a filter which comprises preparing a ceramic honeycomb structure having passages, filling a ceramic slurry mixed with organic solids into the passages and then baking the whole ceramic body to gasify the organic solids thereby producing fine meandering holes in the passages. A porous ceramic body produced by such a method is also proposed.

Abstract: A glow plug for preheating the combustion chamber of a diesel engine. The glow plug has a heat generating portion and a mounting portion. The heat generating portion is provided with a ceramic central electrode made of an electrically insulating material and provided with at least one spiral screw-thread groove formed in the outer peripheral surface thereof. A ceramic electric resistor serving as a heat generating member is disposed in the groove. The electric resistor is made of TiC or SiC with or without addition of Al.sub.2 O.sub.3.

Abstract: An ignition device for a rotary piston engine includes a glow plug which is mounted at an ignition port formed in an engine housing to communicate with a combustion and operation chamber and which, when electrically powered, is heated to red hot to ignite an air-fuel mixture in the combustion and operation chamber. The glow plug ignites the air-fuel mixture through a communicating port which is formed to face the combustion and operation chamber and which has a smaller aperture area than the cross-section area of the ignition port.

Abstract: In a device for purifying the exhaust gases discharged from an internal combustion engine of the type having a secondary air supply pipe for charging the secondary air from an air source such as an air pump into an exhaust pipe upstream of an exhaust gas reactor or the like, a three-way valve is inserted in the supply pipe in such a manner that the three-way valve may be displaced between a first position at which the air source and the exhaust pipe are communicated with each other and a second position at which the communication between them is interrupted and the secondary air is relieved or returned to the air source bypassing the exhaust pipe; an air-fuel ratio sensor is inserted into the exhaust pipe downstream of the opening of the secondary air supply pipe into the exhaust pipe; and means for controlling the three-way valve is provided so that when the air-fuel ratio detected by the sensor is lower than a reference or optimum ratio at which the best performance of the reactor is expected the three-way

Abstract: A secondary air supply pipe line is opened in the exhaust pipe of an internal combustion engine on the upstream side of an exhaust gas reactor which is mounted in the exhaust pipe, and an air-fuel ratio sensor for detecting the air-fuel ratio of exhaust gases is mounted in the exhaust pipe on the downstream side of the portion where the secondary air supply pipe line is open. An air flow control valve for on-off controlling the flow of air in the secondary air supply pipe line is operated in accordance with the output signal of the air-fuel ratio sensor.

Abstract: An ignition system for rotary piston engines includes a glow plug in addition to the normal leading spark plug and trailing spark plug. The glow plug is mounted in the housing of the engine on the leading side with respect to the trochoidal minor axis in the direction of the rotor rotation and performs continuous ignition of the mixture during low speed and load operation of the engine. Thus, during the low speed and load operation the glow plug performs ignition in place of the leading spark plug whereas during other engine operating conditions the leading spark plug and the trailing spark plug perform the ignition of the mixture.

Abstract: The temperature of a glow plug mounted on an epitorocoidal engine housing on a leading side of the torocoid minor axis of a rotary piston engine in the direction of the rotor rotation is sensed. When the sensed temperature exceeds a predetermined temperature within a temperature range which allows the ignition of air-fuel mixture, power to the glow plug is stopped whereby the life of the glow plug is extended and the power consumption is saved.

Abstract: An ignition system for rotary piston engine wherein a glow plug mounted in the epitrochoidal housing of the engine is supplied with electric power to maintain the surface temperature of the glow plug within a range from 900.degree. to 1100.degree. C. A control unit for controlling the supply of electric power to the glow plug produces an output pulse signal the pulse width thereof being varied depending on engine operating conditions such as the amount of fuel supply and engine rotational speeds. A power circuit receives the pulse signal from the control unit and on-off controls the supply of electric power to the plug from a battery.

Abstract: An engine exhaust gas purification system having an exhaust gas reactor mounted on the engine exhaust pipe, a secondary air supply system having a secondary air supply passage connected to the exhaust pipe upstream of the reactor, and an exhaust gas air-fuel ratio detector mounted on the exhaust pipe to detect air-fuel ratio of exhaust gases in the exhaust pipe. A secondary air supply control valve is provided in the secondary air supply passage and controlled by a valve actuator having a diaphragm to which positive pressure of the secondary air and the engine intake vacuum pressure can be applied. The application of the positive and vacuum pressures to the diaphragm is controlled by solenoid valves which are controlled in accordance with the air-fuel detector output voltage which represents the detected exhaust gas air-fuel ratio, whereby the secondary air supply control valve is controlled such that the secondary air is supplied to the engine exhaust gases at a continuously controlled, variable rate.

Abstract: An apparatus for introducing secondary air into an exhaust system of an internal combustion engine, provided with a three-way catalytic converter in the exhaust system. The apparatus includes a first air flow control valve adapted for controlling the amount of air introduced into the exhaust system in accordance with the atmosphere of the exhaust gas so as to cause it to be kept near stoichiometric atmosphere, and a second air flow control valve adapted for preliminarily controlling the amount of secondary air introduced into said first air flow control valve in accordance with the amount of engine fluid passing through the intake system or exhaust system. The atmosphere control operation by the first air flow control valve is effectively promoted by the second air flow control valve, so that atmosphere of the exhaust gas can be strictly and precisely controlled to said stoichiometric atmosphere for proper operation of the three-way catalytic converter.