The Fast Measurement for the Relative Position of Flange-End Holes

For the flange end of the internal combustion engine crankshaft, the position of threaded holes and pinhole relative to the journal reference plane affects the dynamic balance and thermal efficiency of the engine, and therefore, this parameter measurement has a positive significance in the crankshaft manufacture. This paper proposes a system for quickly measuring the relative position of the flange-end holes, which uses a pneumatic linear variable differential transformer to form measuring benches for getting the position of the journal reference plane, and the high precision coordinates of the flange-end holes are obtained by multi-camera. The coordinates of the flange-end holes are merged into the global coordinate system of the journal reference plane, and the experimental result shows that the position uncertainty is better than 0.1 mm. This method has the advantage of convenient loading and unloading, fast measuring speed, and high accuracy and is easily implemented in the flexible manufacturing line for a full inspection of the semi-finished crankshaft.