Research On Blade Edge Measuring Techniques

The engine blade is a important component of aviation engine, which directly effect the engine's thrust-weight ratio, reliability, life and safety. So the blade plays a decisive role in respect of flying speed, effective load capacity and flexibility. The engine blade works in atrocious environment, needs to be designed and tested in advanced technology, this is a knowledge intensive and technology intensive product.In recent years, quality problems with domestically made engine are prominent, of which most of them are for engine blade. The blade inspection and measuring is a critical link in ensuring its quality, while the metro logical characteristics of the blade work edge is a main factor that will effect the blade quality, which directly effects the blade fatigue strength, engine fuel consumption reduction and acceleration, and closely relates to engine reliability and safety. Therefore the measurement of engine blade curvature radius becomes more important.At present, the inspecting means of engine blade in China is not so advanced, which mainly uses traditional inspection method such as template and visual inspection for blade quality. In order to adapt the air engine blade manufacturer's requirements for its production, improve the blade measurement efficiency and accuracy, this paper through study of metrological technology for blade working edge, a measuring instrument for engine blade front edge curvature radius is designed and built up. When the blade is installed under the optical system of the instrument by means of a fixture, the image measured is transferred to computer through CCD, the image edge is abstracted and data is analyzed, and the characteristics to be measured is obtained.