Peak combustion pressure timing detector for IC engine using intake valve deformation

Claim 1

In an internal combustion engine having a rotating crankshaft, a combustion chamber with an intake valve opening thereto, means to introduce a combustible charge through the intake valve opening, means to initiate ignition of the combustible charge, and a poppet valve effective to close the intake valve opening during combustion, the poppet valve comprising a valve closing member deformable by combustion pressure, a stem effective to move longitudinally in response to said deformation and a detectable member effective to move with the stem during the longitudinal movement thereof, peak combustion pressure timing sensing apparatus comprising: a probe fixed with respect to the stationary portion of the engine and disposed adjacent the detectable member so as to be sensitive to the longitudinal position thereof, the probe being effective to generate an output electric signal varying with the longitudinal position of the detectable member and therefore of the valve stem, the output electric signal reaching a detectable peak value concurrent with peak combustion chamber pressure and resulting peak deformation of the valve closing member; and means effective to reference the peak value with the crankshaft rotational position of the engine so as to indicate the timing thereof.