Machining Method of Oil Hole of Medium and High Speed ​​Crankshaft

Abstract

The invention relates to a method for machining oil holes of a medium-high-speed crankshaft. The method includes: firstly, machining crankshaft crossed oil holes: reaming oil hole surfaces flatly, adopting a solid carbide drill to guide holes of crossed minor-diameter deep holes, adopting a gun drill to drill the crossed minor-diameter deep holes by short and long stages, adopting a centering expanding drill, a boring tool, a plate drill and a non-standard drill to drill and bore the minor-diameter deep holes, adopting a non-standard modeling boring tool to machine 120-degree conical surfacesand round angles at bottoms of the minor-diameter deep holes, adopting a precise boring tool to bore top holes in hole openings, and adopting the non-standard modeling boring tool to bore conic sealing grooves in the hole openings in a profiling manner; secondly, machining main journal straight oil holes and crank journal straight holes after crankshaft crossed oil holes are machined: reaming oilhole surfaces flatly, adopting the solid carbide drill to drill through a hard layer to guide, drilling at two radial ends of the medium-high-speed crankshaft with the gun drill, and enabling the mainjournal straight oil holes and the crank journal straight holes to communicate with the large and small holes of the crankshaft crossed oil holes. The method has the advantages that the machined oilholes of the crankshaft are high in size precision, the roughness of the oil holes reaches to Ra1.6, and quality of the oil holes is stable and reliable.

Description

technical field [0001] The invention relates to a processing method for an oil hole of a medium-high speed crankshaft. Background technique [0002] A medium-high speed crankshaft was developed for the first time, and the oil hole of the medium-high speed crankshaft (see figure 1 ) includes main journal straight oil hole 1, crank pin neck straight oil hole 2, and crank cross oil hole. Crankshaft main journals and crankpin journals are subjected to surface quenching treatment, and the hardness reaches HRC50~53. Therefore, drilling the main journals and crankpin journal straight oil holes needs to pass through the hardened layer of the journal, which requires high hardness and processing performance of the drill bit. . The crankshaft crank crossing oil hole is formed by intersecting the large diameter deep hole 4 and the small crossing small diameter deep hole 3 . The length-to-diameter ratio of the cross small diameter deep hole of the crankshaft crank cross oil hole reach...

AI Technical Summary

Problems solved by technology

The length-to-diameter ratio of the cross small diameter deep hole of the crankshaft crank cross oil hole reaches 27:1, and the diameter of the cross large diameter deep hole is more than three times that of the cross large diameter deep hole. Transition, the mouth is a seam 5 and a tapered sealing groove 6, the shape of the entire oil hole is complex and difficult to process

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