Disclosed is a ceramic electric heating element. The ceramic electric heating element is completely wrapped by an insulating layer. The ceramic electric heating element can prevent the occurrence of a short circuit when the ceramic electric heating element is in use or is installed. The strength of the ceramic electric heating element is increased, and the shock resistance is enhanced. The service life of the ceramic electric heating element is prolonged, and the power-on duration of the ceramic electric heating element is prolonged. Moreover, the process is simplified, the structure is simple, and the cost is low.

Described is a glow plug having a casing and a ceramic glow pin protruding out of the casing. The glow pin has a tapered end section inside the casing. A metal protective tube protrudes out of the casing and surrounds the glow pin. The protective tube has a widened end section inside the casing. A center electrode is arranged in the casing and electrically connected to the glow pin. The glow plug includes an annular or sleeve-shaped contact element through which the glow pin projects and to which the tapered end section of the glow pin is soldered. The contact element is at least partly surrounded by the widened end section of the protective tube.

A heater of the disclosure includes: a rod-like ceramic body; a heat-generating resistor including an embedded portion embedded in the ceramic body and an exposed portion drawn out to an outer periphery face of the ceramic body; a metallic member electrically connected to the heat-generating resistor; and a conductive joining member including titanium, the conductive joining member being configured to join the exposed portion and the metallic member together. The conductive joining member includes a first portion in layer form, in which titanium exists in segregation condition, located along an interface with the exposed portion; and at least one second portion in granular form, in which titanium exists in segregation condition, located away from the first portion.

A ceramic glow plug includes a ceramic heater; a tubular sleeve which holds the outer circumference of the ceramic heater with a front end portion thereof protruding from the front end of the sleeve; and a tubular housing which surrounds a rear end portion of the ceramic heater and has a mounting portion for mounting the housing. The sleeve has a small-diameter portion which is accommodated in a front end portion of the housing and has an outer diameter smaller than the inner diameter of the front end portion of the housing, and a large-diameter portion which is connected to the small-diameter portion, disposed frontward of the front end portion of the housing, and has a diameter larger than the inner diameter of the front end portion of the housing. The front end portion of the housing is welded to the large-diameter portion.

A heater includes a ceramic structure; a heat-generating resistor embedded in the ceramic structure; a conductor line connected to the heat-generating resistor; a through-hole conductor having one end connected to the conductor line and the other end led out to a surface of the ceramic structure; and an electrode pad disposed on the surface of the ceramic structure so as to cover the through-hole conductor, the electrode pad being connected to the through-hole conductor. The through-hole conductor has a protrusion which protrudes outwardly beyond the surface of the ceramic structure.

A heater includes a resistor including a heat-generating portion, one or more leads joined to end portions of the resistor, and an insulating base body which covers the resistor and the leads, and a joining portion between the resistor and the leads includes a region where the resistor is spaced apart from the insulating base body by way of the leads over a whole circumference of the resistor when viewed in cross section of the joining portion.

A glow plug including a coil housed in a tube. The coil includes a heating coil made of an NiCr alloy disposed on a front end side, and a control coil connected to a rear end side of the heating coil. The coil has a normal temperature resistance value of 300 m to 500 m. The accumulated amount of heat generated by the heating coil for two seconds from the start of energization is 400 joules or less. The ratio of an inrush current value at the start of energization to a current value two seconds after the start of energization is 1.2 or higher. The control coil has a temperature resistance coefficient of five or higher and a resistance value of 25 m or higher at a portion between a front end of the control coil and L/2, where L is the length of the control coil.

The present invention relates to a heater including a heating element of which a main component is V, Nb, Ta, Mo, or W, leads bonded to respective ends of the heating element, and an insulating base in which the heating element and the lead are embedded, in which the heating element and the insulating base are formed of a sintered body which is integrally sintered, the heating element includes a compound including at least one of V, Nb, Ta, Cr, Mo, W, Mn, or Fe, which is an element different from the element used as the main component of the heating element, and the element is substantially not included around the heating element in the insulating base.

A heater includes a heating element, a pair of lead wires each connected to an end of the heating element, and an insulating base body in which the heating element and the pair of lead wires are embedded. The insulating base body contains a plurality of metal particles around the heating element, the metal particles being separated from the heating element. The plurality of metal particles and the heating element comprise an elliptical cross-section comprising a same major axis direction. With such a structure, when the heater is rapidly cooled to cause a crack on the surface of the insulating base body, the crack develops along the major axis direction of the metal particles and therefore rarely reaches the heating element. This resists breakage of the heating element.

A glow plug including a metal sheath tube having a closed front end; a heating element accommodated within the sheath tube; insulating powder filling the interior of the sheath tube so as to surround the heating element; a rod-shaped metal lead connected to the heating element and inserted into the sheath tube from the rear end thereof; and a seal member located in a seal portion at the rear end of the sheath tube to hermetically seal the gap between the sheath tube and the lead. The glow plug is characterized in that the sheath tube is formed to have a substantially uniform outer diameter over an axial range including and extending beyond a range where the seal portion is formed, and the sheath tube has an engagement projection formed at the seal portion and deformed so as to protrude radially inwardly.