Knocking detector of internal combustion engine

PURPOSE: To realize the detection of knocking with high S/N and high sensitivity, by setting a pressure receiving part toward a prescribed pointing direction in the cooled water of an engine block water room via a supporting member for absorbing vibration and detecting the vibration of water pressure caused by the knocking only. CONSTITUTION: A pressure receiving part 12 is supported in the cooling water in a water room 4 so that the pointing direction is right-angled to a wall 5 by means of a supporting member 14 of rubber or synthetic resin having the vibration absorbing properties which is fixed vertically to an external circumference wall of an engine block via five housings 13. The position where the part 12 is attached is distant away from the vibrating sources such as the cam, valve, bearing, etc. of the engine and accordingly does not receive these vibration noises. Thus no vibration noise is received at the external circumference 5 via a horizontal crank. The wall 5 conveys the cooling water by the directivity of the part 12. As a result, the vibration of water pressure caused only by the knocking which is close to the noise generating source and transmitted in the radial direction of a cylinder is detected. In such way, the knocking can be detected with high S/N and high sensitivity. COPYRIGHT: (C)1982,JPO&Japio