Abstract: An energization control apparatus for a glow plug includes a battery, a glow plug, a power control unit, and an energization controller. The glow plug has a low rated voltage which allows rapid heating at a low battery voltage during cranking of a diesel engine in a severe wintertime condition. The power control unit is arranged between the battery and the glow plug to control a power supplied to the glow plug. The energization controller controls the power control unit so as to equalize a root-mean-square value of a voltage applied to the glow plug to be the low rated voltage when a voltage applied to the glow plug at the start of the diesel engine is detected to be higher than the low battery voltage.

Abstract: A diesel engine glow plug having an elongated hollow electrically conductive holder, which holds a rod-like ceramic heater at one end thereof such that one end of the heater extends outside the holder. An external connecting terminal is positioned in the other end of the hollow holder and electrically insulated from the hollow holder. The ceramic heater is a U-shaped heating element with a pair of parallel lead portions made of a resistive ceramic material extending backward from both ends of the U-shaped heating element and arranged such that the outer surfaces of the lead portions are held by the distal end of the holder through electrical insulating layers between the inner surface of the holder and the outer surface of the lead portions.

Abstract: A glow plug for a diesel engine includes a hollow holder, and a ceramic heater made of SiAlON extending through a distal end portion of the hollow holder and held by it. The ceramic heater is provided with a U-shaped heating element and a pair of lead portions extending backward from both ends of the U-shaped heating element and parallel to each other. The heating element and the pair of lead portions are integrally made of a resistive ceramic material. One of the lead portions is coupled to one end of an electrically conducting flexible wire, the other end of the wire being coupled to an external connecting terminal. A ration .epsilon.(.dbd.SH/SL) of cross-sectional areas SH of the U-shaped heating element to cross-section areas SL of the lead portions falls within the range of 0.15.ltoreq..epsilon..gtoreq.0.6.

Abstract: A glow plug for a diesel engine includes a U-shaped ceramic heater of SIALON supported by a hollow metallic holder. The heater has a U-shaped heating portion projecting from one end of the holder and is supported therein by a pair of parallel ceramic lead portions of a thicknesses greater than the heating portion. One lead portion is electrically connected to the interior of the holder and the other lead portion is electrically insulated from the holder and electrically connected to an external connecting terminal extending into the other end of the holder. The lead portions are spaced from each other to define a slit therebetween open to the interior of the holder. A sintered ceramic sheet of SIALON integrally seals the slit against entry of combustion gases into the interior of the holder.

Abstract: A supply line for supplying a sealant from a sealant supply source to a sealing robot has pressure sensors and is coupled to relief valves through branch lines. If the pressure in the supply line excessively rises or drops, then the relief valves are opened to release the pressure from the supply line and the supply pump is inactivated. The pipes, devices, and pump on the supply line are therefore protected from damage. The sealing robot has an sealant applicator gun movable with respect to an article to which the sealant is to be applied by the sealing robot. A pump driving device is controlled to vary the rate at which the sealant is discharged from the pump as a function of the speed of relative movement of the sealant applicator gun with respect to the article.

Abstract: A glow plug for diesel engines includes a ceramic heater with a U-shaped heating portion and a pair of leads integrally formed with the heating portion and extending backwards from both ends of the heating portion. The heater is supported at one end thereof by a hollow holder in a cantilevered state with one end thereof protruding towards the outside. At least the outside surfaces of the leads are joined to, and held by, the inside of the holder via an insulating layer, and at least the rear ends of the other of the leads are connected via a metallic lead wire to an external connection terminal supported in an insulated state by the rear end of the holder. The ceramic heater is integrally formed from an electrically resistive sintered sialon produced by adding 20-70 vol. % Ti nitride or carbonitride as an electric conductivity donor to .beta.-type sialon or a .alpha./.beta.-type sialon.

Abstract: A diesel engine glow plug includes a hollow holder, a ceramic heater, an electrically conductive annular member, an external connecting terminal, and an insulating sleeve. The annular member is interposed between the rear end portion of the ceramic heater and the distal end portion of the hollow holder. The external connecting terminal engages with the rear end portion of the ceramic heater from the rear end portion of the holder through an interior of the holder. The insulating sleeve is housed in the hollow holder to electrically insulate the external connecting terminal from the hollow holder. The ceramic heater includes a U-shaped heating portion and a pair of parallel lead portions extending backward from the heating portion and terminating in an enlarged diameter portion defining the rear end portion of the heater. One of the lead portions is electrically connected to the holder through the annular member.

Abstract: There is disclosed glow plug for a diesel engine provided with an elongated ceramic heater retained by an opening end of a hollow holder with one end of said ceramic heater being projected toward the outside. The ceramic heater comprises an insulating tubular section of an insulating ceramic material, and a heating body as a continuous conductive section formed so as to cover the outer peripheral portion, the outermost portion and the hollow portion of the insulating tubular section with a conductive ceramic material, the heating body being formed in a manner that the thickness of at least the outer peripheral portion of the insulating tubular member in the vicinity of said one end of the ceramic heater is thinner than that of other portions thereof. The insulating tubular section and the heating body constituting the ceramic heater are integrally formed with the ceramic material which can select insulating property and conductive property by adjusting an amount of titanium nitride added into .beta.

Abstract: A self-regulating temperature controlled glow plug has a hollow metal holder, a rod-like ceramic heater and a power control heater. The ceramic heater extends from one end of the holder and has embedded therein a first resistor of tungsten alloyed with rhenium or molybdenum. The power control heater includes a second resistor embedded in a dense mass of powdered insulation material filling a tubular metallic sheath. The sheath is positioned in the holder with its central portion held in spaced relationship thereto by a thermally insulating spacer at least one end thereof. The second resistor is made of tungsten, iron or nickel, has a positive temperature coefficient of resistance at least equal to and a heating capacity greater than the first resistor, and is connected in series with the first resistor.

Abstract: In a glow plug for use in a diesel engine of the type comprising a first helical heating member, a second helical heating member connected to the first heating member and made of material having larger positive resistance temperature coefficient than that of the first heating member, and a sheath enclosing the first and second heating members, the ratio between the length of the first heating member and the sheath diameter is selected to be less than 1.5, and the resistance ratio at normal temperature of the first and second heating members is selected to lie in a range of from 2.5 to 7.0.

Abstract: A glow plug for use in a diesel engine comprises first and second helical heaters covered with a sheath. The second heater is made of material having larger resistance temperature coefficient than that of the first heater. A gap larger than winding pitches of the two heaters is provided there between and the two heaters are electrically interconnected in the gap.