Ngk Spark Plug Company, Limited

Shunsuke Gotou

Chiaki Kumada

Hiroshi Ono

Yukifumi Chiba

Masanori Ootubo

Hisashi Higuchi

There is provided an energization control apparatus for a glow plug in an engine, including a post-start glow section to control energization of a resistance heater of the glow plug by a battery after start of the engine. The post-start glow section is configured to evaluate revolution stability of the engine and control the energization of the resistance heater according to a first control pattern when the engine revolution stability is higher than or equal to a threshold level and according to a second control pattern that achieves a higher temperature of the sheath heater than the first control pattern when the engine revolution stability is lower than the threshold level.

Glow plug energization control apparatus and method

To provide a glow plug capable of speedily increasing the temperature, a glow plug mounting structure, and a process for manufacturing the glow plug. In the invention, the glow plug () comprises: a cylindrical sheath tube () closed at its front endS) and opened at its base end (K); a cylindrical metal shell () covering the side of the base end (K); a heating coil () arranged in the sheath tube () along the axis thereof and connected at its front end portion (S) to the front end (S) of the sheath tube (); and insulating powder () packed in the sheath tube (). The front end side portion (H) of the heating coil () farther than the foremost end (T) of the lead member () has a coil length not larger than 15 mm in the axial direction from the front end (S) of the sheath tube (). The sheath front end portion (C) enclosing the front end side portion (H) has an outer diameter not larger than 4.4 mm.

Glow plug, glow plug mounting structure, and glow plug manufacturing method

The invention provides a glow plug with an electric resistor made of a material comprising 20 to 60% by weight nickel and less than 5% by weight iron and the balance of cobalt and unavoidable impurities. The glow plug pf the invention attains an excellent quick heating ability, a self-temperature control function, high oxidation resistance, long durability and good workability.

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Ichinomiya, Japan

Shunsuke Gotou