Patent ID: 6414273
Filing Date: 2002-07-02
Classification: F02P

Abstract:
A glow plug control apparatus comprising:a glow plug comprising a housing fixed to an engine, a heating element insulated from said housing which generates heat when energized by electric current supplied through two conductive paths at least either before or after the completion of warming-up of said engine and a ceramic heater having an exposed portion which is heated by said heating element and exposed to the interior of the combustion chamber of said engine; a glow plug energization controlling means for controlling the energization of said heating element of said glow plug depending on the surface temperature of said exposed portion so as to raise or keep said surface temperature to not lower than a predetermined temperature; an ion detecting means for detecting ions in said combustion chamber using said glow plug; a switching means for switching the state of said glow plug from the state of being controlled in energization by said glow plug energization controlling means to the state of ion detection by said ion detecting means or vice versa; and a switching command means for commanding the switching from the state of being controlled in energization to the state of ion detection by said switching mans for a predetermined period of time from the time of injection of fuel into said combustion chamber when the surface temperature of said exposed portion is not lower than said predetermined temperature.