Optimization and Modeling of Radial Pitch Diameter Difference in Tapping of AISI H13

Jie Ren,Xianguo Yan,Yu Meng,Tingting Li,Rui Zhang,Zhi Chen,Antonio Boccaccio

doi:10.1155/2022/9459881

Abstract

The radial pitch diameter difference has a great influence on the quality of the internal thread. However, it is difficult to accurately control the radial pitch diameter difference of the thread in the tapping. Therefore, the influence of various factors on radial pitch diameter difference for tapping AISI H13 steel was studied in this paper. Parameters with optimum radial pitch diameter difference were determined by the Taguchi method, and the tapping experiment was carried out according to Taguchi L18 orthogonal array. Based on the signal-to-noise ratio and variance analysis, the experimental results were evaluated to determine the combination of factors to obtain the smallest radial pitch diameter difference and the influence level of each factor on radial pitch diameter difference, and the prediction equation of radial pitch diameter difference was established through the regression analysis. The results show that the combination of factors to obtain the smallest radial pitch diameter difference is a hone radius of 10 μm, a spindle speed of 100 rev/min, and a chamfer length of 2 pitches; the order of importance of the influencing factors on radial pitch diameter difference is spindle speed, followed by hone radius and chamfer length, and their percentage contribution rates are 61.54%, 24.53%, and 6.16%, respectively; the determination coefficient R2 of the prediction equations is 0.925; the confirmation experiment conducted with 95% confidence level shows that Taguchi method and prediction equation successfully optimize and predict radial pitch diameter difference.

Highlights

Due to the advantages of simple structure, reliable connection, and convenient assembly and disassembly, threaded connections are widely used in energy, aerospace, high-speed rail, automobile manufacturing, and other fields [1,2,3]
Taguchi method uses a signal-tonoise ratio to measure quality characteristics that deviate from the desired value. ere are generally three types of quality characteristics; the-lower-the-better, the-nominalthe-best, and the-higher-the-better. e purpose of this study is to obtain the smallest radial pitch diameter difference (RPDD), so the lower-the-better signal-to-noise ratio (S/N) is adopted. e equation of S/N can be expressed as [18]
Where η is the lower-the-better S/N, yi represents RPDD based on the experimental results, and n represents the number of repetitions in the experiment. e experiment results of RPDD and the corresponding S/N obtained from equation (2) are shown in Table 5. e S/N of each factor is obtained by calculating the arithmetic mean value of its corresponding levels, where the level with the highest S/N is the optimal level of the factor

Summary

Introduction

Due to the advantages of simple structure, reliable connection, and convenient assembly and disassembly, threaded connections are widely used in energy, aerospace, high-speed rail, automobile manufacturing, and other fields [1,2,3]. Tapping is the only method to manufacture small-diameter internal threads [8]. It is usually performed in the final stage of the manufacturing process. It is difficult to guarantee the manufacturing quality of internal threads due to the harsh processing conditions of tapping. In order to improve the thread quality of tapping processing, some scholars have conducted related research. Fernandez Landeta et al [12] compared the manufacturing accuracy of forming taps with different geometric parameters and found that the crosssectional shape and chamfer length have an effect on the accuracy of the thread. E radial pitch diameter difference (RPDD) is regarded as an important parameter for evaluating thread Fernandez Landeta et al [12] compared the manufacturing accuracy of forming taps with different geometric parameters and found that the crosssectional shape and chamfer length have an effect on the accuracy of the thread. e focus of these studies is the thread surface quality, but in many cases, the thread performance cannot be effectively evaluated by the surface quality alone. e radial pitch diameter difference (RPDD) is regarded as an important parameter for evaluating thread

Methods

Results

Conclusion