Heating rod for a glow plug and method for producing a heating rod and glow plug
AssigneeBorgWarner Ludwigsburg GmbH
InventorsMichael Haussner, Martin Allgaier
Life of this patent
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Abstract
This document describes a heating rod for a glow plug with a ceramic glow element having a glow tip at its front end and a connector portion at its rear end, a contact element making electrical contact with the connector portion of the glow element, and a sheath, from which the front end of the glow element protrudes. According to this disclosure, the contact element is pressed against the glow element under pre-tension. Furthermore, this document describes a method for producing such a heating rod and a glow plug with such a heating rod.
Claims16
A heating rod for a glow plug, comprising:
- a ceramic glow element having a glow tip at its front end, an electrically conductive core, an outer conductor electrically connected with the conductive core at the glow tip, an insulating layer disposed between the conductive core and the outer conductor, and a connector portion at its rear end, the connector portion having a conical shape;
- a contact element electrically contacting the connector portion of the glow element, the contact element having a conically shaped receptacle which receives the connector portion of the glow element and is thereby electrically connected to the conductive core of the ceramic glow element, the contact element further including a rearward facing shoulder;
- and
- a sheath, the glow element protruding from the front end of the sheath and the rearward facing shoulder of the contact element being disposed within the sheath;
- wherein the contact element is pressed against the glow element under pre-tension exerted by the sheath.
A method for producing a heating rod, comprising:
- inserting a ceramic glow element into a sheath, the ceramic glow element having a glow tip at its front end, an electrically conductive core, an outer conductor electrically connected with the conductive core at the glow tip, an insulating layer disposed between the conductive core and outer conductor, and a connector portion at its rear end, the connector portion having a conical shape;
- making electrical contact between the conductive core at the connector portion of the glow element and a contact element, the contact element having a conically shaped receptacle which receives the connector portion of the glow element when making electrical contact;
- and
- creating a pre-tension in the sheath which presses the contact element against the glow element by heating a section of the sheath and creating a circumferential indentation in the sheath by plastic deformation by pressing a tool into the heated section of the sheath.
Dependencies are inferred from the claim text.