KNOCKING DETECTING DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To eliminate the necessity to install a band pass filter for the electric circuit that follows a knocking detecting device and reduce the cost of the electric circuit by using a tuning fork vibration element that opens at its one end in a case that vibrates as one body with the main body of an internal combustion engine and is attached to it. CONSTITUTION:The case 1 of a knocking detecting device is made to vibrate as one body with the internal combustion engine by means of screw section 1a, and a V-letter shaped tuning fork vibration element 2 is secured on the lid 4 of the case by bolting or welding or other method. This tuning fork has its intrinsic frequency that is the same as the frequency of knocking. Accordingly only vibrations that have frequencies near the frequency of knocking of the internal combustion engine are detected as large electric output from the vibration element 2, which makes unnecessary the band-pass filter in the electric circuit that follows the vibration element, making this circuit simple and lowering its cost.