Strong preloaded crankshaft machining technology

Abstract

The invention relates to a strong preloaded crankshaft machining technology. The strong preloaded crankshaft machining technology is characterized by firstly carrying out rough machining on a crankshaft, finely turning shaft necks and round corners of a main shaft and a connecting rod by adopting a turning lathe after the crankshaft is subjected to the rough machining, carrying out strong rolling on the shaft necks and the round corners of the main shaft and the connecting rod by a rolling machine tool after fine turning is completed, and enabling the rolling resultant force which is loaded on a rolling cutter to be 32000-40000N, the rolling turns to be 6-8 and the radial run-out of a main shaft neck of the crankshaft to be controlled within 0.15-0.3mm after rolling; carrying out fine grinding after the strong rolling is completed. After the shaft necks and the round corners of the main shaft and the connecting rod are finely turned by the turning lathe, the machining allowance of the main shaft neck is reserved by 1.0-1.4mm, the machining allowance of the shaft neck of the connecting rod is reserved by 0.6-1.0 mm, the round corners can be machined according to the lower limit of a finished round corner of the crankshaft, and the center distance is deviated to the direction of the connecting rod by 0.05-0.1 mm. According to the strong preloaded crankshaft machining technology disclosed by the invention, the technological process is reasonable, the machining is simple and convenient, and the quality problems of bearing score of an engine caused by rolling embossment of the crankshaft and over-proof form and location tolerance can be fundamentally prevented from happening; the strong preloaded crankshaft machining technology is particularly suitable for machining medium-power and high-power spheroidal graphite cast iron crankshafts.

Description

technical field [0001] The invention relates to a crankshaft processing technology, in particular to a powerful preload crankshaft processing technology. Background technique [0002] The crankshaft is one of the key components of the engine. During the high-speed operation of the engine, it bears the explosive pressure, inertial force and moment of inertia of the gas. The force is large and very complicated, and it bears the impact of alternating loads. These alternating loads are easy to Stress concentration such as bending and torsion on the crankshaft will cause fatigue cracks. Fatigue cracks mainly appear at the transition fillet of the crankshaft, and eventually cause the crankshaft to break at the transition fillet. Therefore, in the process of crankshaft processing, it is necessary to adopt strengthening technology to strengthen the transition fillet. At present, induction hardening, ion nitriding, gas soft nitriding, rolling strengthening and other crankshaft streng...

AI Technical Summary

Problems solved by technology

Since the journal is rolled after fine grinding, there will be a rolling protrusion at the transition between the fillet and the journal after rolling. Due to the cold hardening of the rolling, the hardness of the protrusion is high and it is not easy to repair; and it will There are quality problems such as out-of-tolerance runout, out-of-tolerance journal roundness, cylindricity, and out-of-perpendicularity caused by rolling deformation. Mechanical damage such as rolling scars and strains is also prone to occur during processing, and it is difficult to repair. Problems will lead to an increase in unqualified crankshaft products, and even cause abnormal engine wear and tear, etc.