Combustion pressure peak detector for combustion control for an internal combustion engine

Claim 1

In a combustion pressure peak detector for the combustion control of an internal combustion engine of the type having a block and cylinder head defining at least one combustion chamber and having at least one headed bolt adjacent said combustion chamber for securing said cylinder head to said engine block, said combustion pressure peak detector comprising a first metallic cup-shaped pressure member having a central hole therein, an annular plate-shaped ceramic piezo-electric unit disposed in said first pressure member, a second metallic cup-shaped pressure member having a central hole telescopically engaging said first cup-shaped pressure member and disposed in engagement with said piezo-electric unit, said first and second pressure members and said piezo-electric unit surrounding said bolt with one of said pressure members disposed in engagement with said cylinder head and the other of said pressure members being disposed in engagement with the head of said bolt, interfitting means on said first and second pressure members for permitting movement of said pressure members toward and away from each other while preventing relative rotation between said pressure members, and circuit means for detecting a signal provided by said piezo-electric unit to determine the combustion peak pressure in said combustion chamber.