Method for machining high-accuracy special profile of elongated rod

Abstract

A method for machining a high-accuracy special profile of an elongated rod comprises the processes of blanking, rough machining, de-stressing, semi-finish machining, heat treatment, datum correction and finish machining. During blanking, the quality of the raw material state is improved to determine an optimum hardness value; by collection of similar part machining data and analysis of conventional technological processes, main factors and processes affecting the needle plug quality are determined, the technological processes are adjusted, and the de-stressing process is added after rough machining and before semi-finish machining, accordingly, effects of residual stress of machining in the subsequent heat treatment process are eliminate; before finish machining, the correction process is added for correcting a machining datum, so that the machining accuracy is guaranteed; and a high-accuracy curved surface is subjected to one-step clamping machining through a high-accuracy numerically-controlled lathe and is cut through an imported cutter, reasonable machining parameters are searched, rough and finish machining allowances are reasonably distributed, and elongated rod special-profile parts are machined to the accuracy meeting technological requirements.

Description

technical field [0001] The invention belongs to the field of mechanical processing, and in particular relates to a processing method for a special profile of a slender rod. Background technique [0002] Slender rod parts are often used in modern industry, and the precision of parts is required to be high. Such as figure 2 The parts shown are slender steel parts, and have high-precision matching outer circles and complex curved surfaces with high shape tolerances and high dimensional requirements. The lathe can turn in place at one time, but cannot meet the high-precision surface requirements of the parts, and there are the following problems: [0003] 1. Influence of materials: The material grade of this part is: 3J53 (material technical requirements: YB / T5256-1993), and its characteristics are: the raw material is not in good condition, the material is soft, and the release of internal stress leads to deformation of the part; [0004] 2. Influence of the structure: It ca...

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Problems solved by technology

like figure 2 The parts shown are slender steel parts, and have high-precision matching outer circles and complex curved surfaces with high shape tolerances and high dimensional requirements. The lathe can turn in place at one time, but cannot meet the high-precision surface requirements of the parts, and there are the following problems:

[0004] 2. Influence of the structure: It can be seen from the structural soil that the part is a slender rod with a relatively large length and diameter (22.2mm), many changes in the profile size, and high processing and testing requirements

One end of the part is composed of a conical surface, a spherical surface, etc. to form a streamlined appearance, and the entire surface has a runout requirement of 0.03 for the reference of the other end, which is almost impossible to achieve by ordinary machining methods;

[0005] 3. The rigidity of the parts is poor: the total length of the parts is 80mm, the minimum diameter is Ф3, and the maximum diameter is Ф5.5. The ability to withstand cutting is poor, and it is easy to deform during processing, which affects the dimensional accuracy

Due to stress release after processing, it is also prone to deformation, resulting in unqualified parts;

[0006] 4. Low processing efficiency

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