Method and system for measuring interference between valve and piston of an internal combustion engine

A system for measuring interference between a valve and a piston which comprises:

• a camshaft, crankshaft and injection pump shaft connected through power transmission means,
• the crankshaft containing a sprocket, a crankshaft fist angle detecting means for detecting the crankshaft rotational angle from the crankshaft sprocket,
• an injection pump shaft second angle detecting means for detecting the injection pump shaft rotational angle, said first and second angle detecting means measuring the torsional distortion deviation of the crankshaft and injection pump shaft when torque, equaling a camshaft distortion torque measuring with the in a fixed state, is given either to the crankshaft or the injection pump shaft, said camshaft distortion torque being measured by a strain gauge provided at a location in the camshaft where distortion caused by torque from power transmission is most severe,
• reflective tape adhered to an outside circumference of sprockets provided on each shaft, the reflective tape being made of a material which reflects light;
• torsional vibration detecting means for emitting light toward each sprocket of each rotating shaft and receiving the reflection of this light, reflected by the reflective tape, and for outputting the vibration of each shaft as an AC component signal;
• amplifying means for amplifying said output AC component signal;
• recording means for storing, in a predetermined format, piston position information and AC component signals related to the vibration of each shaft;
• and
• waveform display means for graphically displaying the information of the piston position and the AC component signal relating to vibration of each shaft;
• wherein said strain gauge comprises four resistors connected to each other through a Wheatstone bridge having first and second output terminals, and the system further comprises,
• a first signal processor for processing signals output from the first output terminal of the Wheatstone bridge;
• a second signal processor for processing signals output from the second output terminal of the Wheatstone bridge;
• and
• a controller for analyzing signals from the first and second output terminals to determine camshaft distortion, and calculating standard torque from the determined camshaft distortion value and outputting the same;
• and
• wherein the crankshaft angle detecting means performs a photo interrupting process on gear teeth of the crankshaft sprocket.