A ceramic heater-type glow plug that includes a ceramic heater, and a metallic outer cylinder, one end side of which holds the ceramic heater and the other end side of which is inserted in and fixed to an inner hole of a housing.

A ceramic heater including a columnar substrate and a heat generation resistor embedded in the substrate. A taper surface (12) having a contour L1 extending along an imaginary ellipse E is composed of a plurality of successively arranged curved surfaces which decrease in radius of curvature toward the forward end with respect to the direction of an axis P. The taper surface (12) is such that the distance between the end points M1 and M2 of the contour L1 is large in the direction of the axis P, and the angle between the axis P and a tangential line of the contour L1 on the side toward the forward end surface (11) is larger than the angle between the axis P and a tangential line of the contour L1 on the side toward the side circumferential surface (15).

Methods for producing a glow plug having a housing, a ceramic glow pin and a protective tube from which a section of the glow pin projects which is thinner than a thicker section arranged in the protective tube. The thinner section leads to a glow tip. The glow pin is inserted into the protective tube and the protective tube is inserted into the housing. A securing element is placed onto the first end of the glow pin. The internal diameter of the securing element is smaller than the maximum diameter of the glow pin. The securing element is fastened on the protective tube. Alternatively, the protective tube is heated locally at a section of the protective tube surrounding the thinner section, and there the interior width of the protective tube is reduced to a value smaller than the diameter of the thicker section of the glow pin.

A method of making a hot surface igniter is described. A silicon carbide composition that includes both fines fraction and a coarse fraction is sintered in a nitrogen and argon reducing atmosphere in a manner that controls the incorporation of nitrogen with in the lattice of recrystallized silicon carbide. The controlled incorporation of nitrogen in the lattice provides enhanced control over heating and electrical properties, while simultaneously achieving a lower surface area fully recrystallized structure for oxidation resistance and long service life.

The invention relates to a glow plug comprising a housing, a ceramic pencil-type glow element which projects from the housing with a first end and is arranged inside the housing with a second end, a feed line which is arranged in the housing and leads to the pencil-type glow element, and a sleeve-type element which surrounds a section of the pencil-type glow element projecting from the housing. The invention is characterized in that the pencil-type glow element has a section surrounded by the housing which section tapers towards the second end, the pencil-type glow element is encircled by a contact element in the housing, which contact element has a section that narrows towards the second end of the pencil-type glow element, said narrowing section encircling at least a subsection of the tapered section of the pencil-type glow element. The invention further relates to a method for producing said glow plug.

A method of making a hot surface igniter is described. A silicon carbide composition that includes both fines fraction and a coarse fraction is sintered in a nitrogen and argon reducing atmosphere in a manner that controls the incorporation of nitrogen with in the lattice of recrystallized silicon carbide. The controlled incorporation of nitrogen in the lattice provides enhanced control over heating and electrical properties, while simultaneously achieving a lower surface area fully recrystallized structure for oxidation resistance and long service life.

A ceramic heater wherein in at least one cross section of the ceramic heater orthogonal to the axial direction, a first resistor cross section has no protrusion on a first inner portion of the contour of a first resistor cross section, and has two or more protrusions on a first outer portion of the contour of the first resistor cross section and a method of manufacturing the ceramic heater.

A configuration and manufacturing steps of a ceramic heater-type glow plug are simplified when compared to a related art, and a fracture therein is prevented.

A ceramic heater-type glow plug that includes a ceramic heater, and a metallic outer cylinder, one end side of which holds the ceramic heater and the other end side of which is inserted in and fixed to an inner hole of a housing.

A glow plug includes a housing having an axial hold and provided with a screw portion, and a heater member inserted into the axial hole. The housing includes a front-end-side body portion extending to the front end side from a front end of the screw portion, and a gasket portion lying adjacent to a front end side of the front-end-side body portion and bent at a bent portion provided at a rear end thereof so that at least a rear end portion thereof extends in a direction intersecting a direction of an axis. The gasket portion includes a pressure contact portion in which a surface thereof located at an outer circumferential side is brought into pressure contact with a seat surface of an internal combustion engine when the screw portion is screwed into a mounting hole in the internal combustion engine.

A preheater assembly of a glowplug and a hollow sheath extending longitudinally from a bottom external zone to a top external zone, the sheath extending radially from an inside surface defining a cavity towards an outside surface, the glowplug being inserted in the cavity, the tip projecting from the sheath through the bottom external zone, the inside surface of the sheath presenting a second thread meshing with a first thread of the glowplug, the inside surface of the sheath presenting a first conical seat bearing against the first conical bearing surface of the glowplug, the outside surface of the bottom external zone having a third thread screwed into a cylinder head and a second bearing surface that bears against the second seat of a cylinder head.