Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Toshiyuki Oyama

Yoshito Isei

Ryota Ohashi

Around a crankshaft (S) supported by a support device (), a first shape measuring device () to a fourth shape measuring device () are disposed, and the crankshaft (S) and the first shape measuring device () to the fourth shape measuring device () are relatively movable in an axial direction (X direction) of the crankshaft (S). The first shape measuring device () and the third shape measuring device () are disposed so as to face to one X direction and acquire partial shape information (including the other side surfaces in the X direction of counterweights (S)) of the crankshaft S, and further, the second shape measuring device () and the fourth shape measuring device () are disposed so as to face to the other X direction and acquire partial shape information (including one side surfaces in the X direction of the counterweights (S)) of the crankshaft S. This makes it possible to accurately inspect a shape of the crankshaft (S) in a short time.

Crankshaft shape inspection apparatus, system and method

The present invention provides a method for inspecting a crankshaft, which enables accurate detection of defects which occur partially in the crankshaft, such as underfills and dent flaws, by discriminating these defects from bending and torsion over an entire length of the crankshaft. The present invention includes steps of: acquiring three-dimensional point cloud data over an entire length of a measurement object region of a crankshaft S by an optical three-dimensional shape measurement device; dividing the acquired three-dimensional point cloud data to create a plurality of subregion three-dimensional point cloud data, each of the subregion three-dimensional point cloud data respectively corresponding to each of a plurality of subregions of the crankshaft along a direction parallel to the rotational center axis L of the crankshaft; translating and rotating each of the created subregion three-dimensional point cloud data to superpose each of the subregion three-dimensional point cloud data on a surface shape model of the crankshaft, such that a distance between each of the subregion three-dimensional point cloud data and the surface shape model becomes minimum; and detecting a partial defect such as an underfill of the crankshaft based on a distance between each of the subregion three-dimensional point cloud data after being superposed and the surface shape model.

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Tokyo, Japan

Toshiyuki Oyama