US 2014/0111213 A1Published application

Apparatus and method for static testing a spark plug assembled in an internal combustion engine including cracked ceramic insulator detection

AssigneesBauer Associates, Inc., d/b/a Bauer Controls, GM Global Technology Operations LLC

InventorsThomas M. Cunningham, Harold M. Ryan

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Abstract

An apparatus and method is provided for testing a spark plug after the spark plug is assembled in an internal combustion engine. The apparatus includes a high voltage test probe to mechanically probe the spark plug. The high voltage test probe includes a non-electrically conductive part, an electrically conductive ring substantially shielded by the non-electrically conductive part, and a high voltage contactor for electrically connecting to a terminal end of the spark plug. The apparatus also includes a high voltage control box having a high voltage source and an electrical ground, and including at least one of an insulator crack detection circuit and a spark plug firing circuit. The method includes using the apparatus to test assembled spark plugs.

Claims8

Dependent claims

An apparatus for testing a spark plug after the spark plug is assembled in an internal combustion engine wherein the spark plug has a center electrode surrounded by an insulator and electrically connected to a terminal end, and a side electrode electrically connectable to an electrical ground and configured to form a spark plug gap between the center electrode and the side electrode, the apparatus comprising:

a high voltage test probe to mechanically probe the spark plug and having a non-electrically conductive part, an electrically conductive ring substantially shielded by the non-electrically conductive part, and a high voltage contactor for electrically connecting to the terminal end of the spark plug;
and
a high voltage control box having a high voltage source and an electrical ground and including at least one of:
an insulator crack detection circuit for connecting the high voltage contactor to the electrical ground and the electrically conductive ring to the high voltage source to generate an insulator crack detection signal indicating if an insulator is cracked, and
a spark plug firing circuit for connecting the high voltage contactor to the high voltage source to fire the spark plug in a firing test and to generate a spark plug firing signal indicating if the spark plug gap is within specification.

2 more elements

A method for testing a spark plug after the spark plug is assembled in an internal combustion engine wherein the spark plug has a center electrode surrounded by an insulator and electrically connected to a terminal end, a side electrode electrically connectable to an electrical ground and configured to form a spark plug gap between the center electrode and the side electrode, the method comprising:

placing a high voltage test probe over substantially all of the spark plug extending from the internal combustion engine to mechanically probe the spark plug, wherein the high voltage test probe has a non-electrically conductive part, an electrically conductive ring substantially shielded by the non-electrically conductive part, and a high voltage contactor for electrically connecting to the terminal end of the spark plug;
and
at least one of:
connecting the high voltage contactor and the electrically conductive ring to a high voltage control box so that an insulator crack detection circuit in the high voltage control box connects the high voltage contactor to an electrical ground and the electrically conductive ring to a high voltage source thereby generating an insulator crack detection signal indicating if an insulator is cracked;
and
connecting the high voltage contactor to the high voltage control box so that a spark plug firing circuit in the high voltage control box connects the high voltage contactor to the high voltage source thereby generating a spark plug firing signal indicating if the spark plug gap is within specification.

3 more elements

Dependencies are inferred from the claim text.