Grinding method of outer circles of high-precision slender casing parts

Abstract

The invention discloses a grinding method of outer circles of high-precision slender casting parts. Workpieces the slenderness ratios of which are more than 10 are generally defined as slender workpieces, the slender workpieces are easy to deform and large in processing difficulty in the grinding process, and the coaxiality of outer circles relative to inner holes is difficult to be ensured. In the invention, a positioning device, a clamping method, grinding parameters and grinding steps of outer circles of high-precision slender casting parts are also provided. Compared with the original grinding method, the grinding method disclosed by the invention has the characteristics that: the original conicity spindle is changed into a cylindrical straight spindle; in the clamping method, the original mode that the conical spindle penetrates into a workpiece hole and the workpiece rotates under the driving of the frictional force is changed into a mode that the workpiece is tensioned by a heart carrier by adopting a double-strand elastic rope to drive the workpiece to rotate in a symmetrical and balanced way; and more reasonable grinding wheel and grinding parameters are selected. The grinding method disclosed by the invention has the advantages that: the index yield of coaxiality of the outer circles relative to the inner holes is improved to 98 percent from 81.6 percent, and the machining efficiency is improved by 25 percent; in addition, the matching grinding difficulty and quantity of the spindles are greatly reduced, and the fixture investment cost is reduced.

Description

technical field [0001] The invention relates to a grinding method for the outer circle of workpieces, in particular to the processing of slender valve sleeve workpieces with a length-to-diameter ratio greater than 10. Background technique [0002] High-precision slender valve sleeve workpieces are common in aviation hydraulic products, and the aspect ratio is greater than 10. Due to the slender workpieces, high precision requirements, difficult processing, and unstable quality. When finely grinding the outer circle, it is required that the coaxiality of the outer circle relative to the reference inner hole is not greater than Φ0.02mm. Generally, the taper mandrel is used for contact positioning with the reference cylindrical hole of the workpiece for cylindrical grinding. Since the taper mandrel penetrates into the workpiece hole, the workpiece is driven to rotate by the friction torque generated by the slight elastic deformation between the workpiece and the mandrel. The p...

AI Technical Summary

Problems solved by technology

Generally, the taper mandrel is used for contact positioning with the reference cylindrical hole of the workpiece for cylindrical grinding. Since the taper mandrel penetrates into the workpiece hole, the workpiece is driven to rotate by the friction torque generated by the slight elastic deformation between the workpiece and the mandrel. The positioning method has high requirements on the geometric accuracy of the positioning reference hole. When the mandrel is inserted, it may be deformed due to the error of the reference hole shape, and the positioning surface is small. The workpiece may be accidentally loosened during grinding. The above reasons may cause coaxial degree of tolerance

Secondly, due to the high precision requirements of the workpiece, the taper of the taper mandrel cannot be too large, the mandrel and the workpiece need to be adapted one by one, and the input of the mandrel is large; in addition, the grinding process of the mandrel and the penetration of the mandrel into the inner hole of the workpiece The degree of tightness requires higher skills for the processor

Images