Provided is a glow plug assembly having dual terminals formed to enable a fast response and reliable control thereof by preventing noise generation caused by grounding, and the assembly including: a housing; a heating tube; a cap; first and second terminals of which lower parts enter inside the heating tube; and a heating coil of which opposite ends are engaged with the first and the second terminals, and a winding part is placed close to the heating tube, wherein the first terminal is shorter than the second terminal in length and is engaged with the heating coil, and the second terminal extends downward to be longer than the first terminal in length, and has a bent part that leads the second terminal to a center of the wound heating coil to secure an insulation space relative to the heating coil, and is engaged with the heating coil.

A method for manufacturing a ceramic heater-type glow plug (1) that includes: a ceramic heater (11); and a metallic outer cylinder (12) that holds the ceramic heater at one end and has the other end inserted in and fixed to a metallic housing (14), the housing having a first housing section (14a) and a second housing section (14b) coaxially arranged with each other, the method for manufacturing a ceramic heater-type glow plug includes the steps of: inserting the ceramic heater in the outer cylinder; inserting the outer cylinder in the first housing section, the second housing section, and a ring-shaped filler material (18) in a state where the filler material is interposed between the first housing section and the second housing section; and joining the first housing section, the second housing section, and the outer cylinder by welding at a position where the filler material is provided.

A method for manufacturing a ceramic heater-type glow plug that includes: a ceramic heater; a metallic outer cylinder that holds the ceramic heater at one end and has the other end inserted in and fixed to a metallic housing; and lead wire that is connected to the ceramic heater and electrifies the ceramic heater, the method for manufacturing a ceramic heater-type glow plug includes the steps of: forming a metalized layer in a region of the ceramic heater that is connected to the lead wire; press-inserting at least the metalized layer of the ceramic heater in a connection fitting that connects the ceramic heater and the lead wire; and heating the ceramic heater and the connection fitting at a temperature at which a material for forming the metalized layer is brought into a semi-molten state and joining by mass transfer between the connection fitting and a solid layer of the metalized layer.

There are described methods and systems for operating a glow plug. The method comprises monitoring a glow plug current; applying a nominal voltage V.sub.N to the glow plug when the glow plug current is between an upper threshold I.sub.1 and a lower threshold I.sub.2<I.sub.1; applying a voltage V.sub.H>V.sub.N to the glow plug when the glow plug current exceeds the upper threshold I.sub.1; and applying substantially no voltage to the glow plug when the glow plug current falls below the lower threshold I.sub.2.

There are described methods and systems for operating a glow plug. The method comprises monitoring a glow plug current; applying a nominal voltage V.sub.N to the glow plug when the glow plug current is between an upper threshold I.sub.1 and a lower threshold I.sub.2<I.sub.1; applying a voltage V.sub.H>V.sub.N to the glow plug when the glow plug current exceeds the upper threshold I.sub.1; and applying substantially no voltage to the glow plug when the glow plug current falls below the lower threshold I.sub.2.

There are described methods and systems for operating a glow plug. The method comprises monitoring a glow plug current; applying a nominal voltage V.sub.N to the glow plug when the glow plug current is between an upper threshold I.sub.1 and a lower threshold I.sub.2<I.sub.1; applying a voltage V.sub.H>V.sub.N to the glow plug when the glow plug current exceeds the upper threshold I.sub.1; and applying substantially no voltage to the glow plug when the glow plug current falls below the lower threshold I.sub.2.

A method of servicing a gas turbine engine having an igniter socket, the method comprising: inserting a glow plug into the igniter socket of the gas turbine engine until a rod end of a glow plug heater rod of the glow plug is exposed to a combustion chamber of the gas turbine engine; and blocking a gap between the glow plug heater rod and an aperture defined in a combustor liner of the gas turbine engine to block fluid communication between the combustion chamber and an environment outside the combustion chamber via the aperture.

A method of servicing a gas turbine engine having an igniter socket, the method comprising: inserting a glow plug into the igniter socket of the gas turbine engine until a rod end of a glow plug heater rod of the glow plug is exposed to a combustion chamber of the gas turbine engine; and blocking a gap between the glow plug heater rod and an aperture defined in a combustor liner of the gas turbine engine to block fluid communication between the combustion chamber and an environment outside the combustion chamber via the aperture.

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 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.