Patent ID: 7171846
Filing Date: 2007-02-06
Classification: F02D,F02P,F23Q,G01L

Abstract:
1. An in-cylinder pressure detection device for detecting an in-cylinder pressure as a pressure within a cylinder of an internal combustion engine, comprising: a housing that has a pair of end walls opposed to each other and is screwed into a body of the engine; an in-cylinder pressure-transmitting member that extends through said housing, said in-cylinder pressure-transmitting member having one end projecting into the cylinder, and a flange part accommodated in said housing; a first piezoelectric element that is accommodated in said housing and sandwiched between one of said end walls and said flange part in a preloaded state, said first piezoelectric element distorting according to the in-cylinder pressure transmitted via said in-cylinder pressure-transmitting member to output a first detection signal indicative of the in-cylinder pressure; and a second piezoelectric element that is accommodated in said housing and sandwiched between the other of said end walls and said flange part in a preloaded state, said second piezoelectric element distorting in a direction opposite to a direction of distortion of said first piezoelectric element according to the in-cylinder pressure transmitted via said in-cylinder pressure-transmitting member to output a second detection signal indicative of the in-cylinder pressure.