Engine crankshaft fatigue crack laser repairing and strengthening device and method

Abstract

The invention discloses an engine crankshaft fatigue crack laser repairing and strengthening device and method. The device comprises a computer control processing system, a coaxial atomizing powder feeding unit, a laser cladding unit and an auxiliary working system. Repairing and strengthening effects of laser cladding to fatigue cracks are fully utilized, namely, the fatigue cracks of an engine crankshaft are subjected to laser cladding, high-quality surface cladding coatings are obtained at filleted corners of the crankshaft, high-amplitude residual compressive stress is generated, fatigue resistance of the crankshaft is improved effectively, mechanical property of the crankshaft is improved comprehensively, fatigue lives of the crankshaft are greatly prolonged, and the purposes of prolonging the life and improving the reliability of the crankshaft are achieved.

Description

technical field [0001] The invention relates to a device and a method for strengthening the surface of a workpiece by using a laser, in particular to a device and a method for repairing and strengthening fatigue cracks of an engine crankshaft by laser. Background technique [0002] The vigorous development of the automobile industry has put forward higher requirements and expectations for the automobile manufacturing industry. The new generation of national IV / V emission standard vehicles requires better safety and higher operational reliability. As the core component of the whole car, the engine has a decisive influence on the overall performance of the car. When the engine is working, the maximum temperature in the cylinder can reach more than 2500K, and the maximum pressure can reach 5~9MPa. Now the maximum speed of the automobile engine can reach 4000~6000r / min. The crankshaft is the most concentrated and most complicated stress of the automobile engine. part. The fail...

AI Technical Summary

Problems solved by technology

However, due to the limitation of the crankshaft processing technology, the fillet rolling of each journal is difficult to match with the rolling, which often results in the phenomenon of gnawing and cutting of the fillet. Moreover, the crankshaft is deformed after rolling, and the effect is not good.

Shot peening can effectively avoid the above situation, but the shot peening process has a great influence on the surface roughness of the crankshaft, and the residual stress formed by shot peening is generally only 0.1~0.8mm

The Chinese patent with the patent number CN101575705A discloses a laser cladding repair process for a failed crankshaft. The modification and enlargement mainly uses the laser cladding process to recreate the failed parts of the workpiece, so that the workpiece will not be scrapped due to the failure of the geometric structure size, but the whole process It cannot be automated, and at the same time, it cannot fundamentally solve the fatigue crack defect of the crankshaft

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