Glow plug arranged for measuring the ionization current of an engine, and method for manufacturing the same

A method of fabricating a glow plug for diesel engines, comprising the steps of:

• providing a metal tubular body;
• providing a heating element including a metal sheath, a heating resistor electrically connected at one end to the sheath and being contained inside the metal sheath, a first terminal electrically connected to another end of the resistor, and a second terminal electrically connected to the sheath;
• and
• depositing a layer of insulating material on a portion of the outer surface of the sheath;
• and
• forming an interference fit between the heating element and tubular body by driving the heating element into the tubular body, such that the layer of insulating material is in direct contact with the metal sheath and metal tubular body to thereby electrically insulate the metal sheath from the metal tubular body.

A method of fabricating a glow plug for diesel engines, comprising the steps of:

• providing a metal tubular body;
• providing a heating element including a metal sheath, a heating resistor electrically connected at one end to the sheath and being contained inside the metal sheath, a first terminal electrically connected to another end of the resistor, and a second terminal electrically connected to the sheath;
• and
• depositing a layer of insulating material on a portion of the outer surface of the sheath;
• and
• fixing the heating element to the metal tubular body with the layer of insulating material disposed between the heating element and tubular body;
• wherein the step of providing the heating element further comprises deforming the sheath at an open end of the sheath by radial compression of the sheath, and wherein the depositing step further comprises applying the insulating material to the sheath after the deforming step.