Research for optimizing the fabricating process of precision locknuts

• Main Authors: Hung-Wen Wang, 王鴻文
• Other Authors: Chih-Ming Chen, Ph.D.
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/30963210489824707537

碩士 === 國立勤益科技大學 === 機械工程系 === 100 === This paper brings up the conduction for optimizing the fabricating process for precision locknut by combination of Taguchi method and simulating anneal method, and promotes the mechanical property of precision locknut by adjusting the conditions of fabricating process to optimize the fabricating process. Firstly, we can obtain the parameters of optimized fabricating process by finding out the best set of parameters and quality characteristics (friction coefficient, ratio of anti-loose, ratio of axial force). This paper determines the control factors (parameters of manufacture) according to the parameters usually applied by the manufactory, even if there is difference of selection for the parameter between different users because of their subjective sense. We can find out the parameters and regression equation of quality characteristics to specify the relation between the parameters and the quality characteristics. Moreover, we can obtain the energy function of simulating anneal method, determines the initial value, and then stack and substitute it. In each substitution step, this method uses present solution to be a subject, then produces a new adjacent solution in random. Replace the adjacent solution with the present solution when the subject function of the adjacent solution is better than the subject function of the present solution. Accompanying with decreasing of temperature, the probability of acceptance of bad solution is lower. It only accepts the better solution when the temperature reaches bottom, and finally achieves convergence. In first step of simulating anneal method, we use Taguchi parameters to be boundary condition so as to find out the best solution. If find out best parameter partially solved at the boundary in first step, it means that there will be more suitable solution can be found out. Extending the best parameter of boundary working factor to make one more time’s optimization is called two-step optimization in this paper. Therefore, this paper proposes to find out the more suitable solution by optimization of two-step simulating anneal method. We can find out Taguchi parameters to be the manufacturing parameters of boundary solution according to afore-mentioned method, extend to the working limit scope of industrial circle in sequence, and finally solve the best suitable solution of the two steps by simulating anneal method. However, even if the best manufacturing parameters have been find out, the condition of manufacture can’t be totally improved because of the real economic condition. We must realize the influence of the manufacturing parameters on the characteristic of quality, then the industrial circle can apply it completely. In this paper, we use sensitivity analysis, and sensitivity of manufacturing parameter influence on mechanical property of precision lock nut. In the example with static condition of flank lock type precision lock nut platform and working variable factor, best sensitive parameter is effective match gap, best sensitive parameter of ratio of anti-loose is working end face. For example with static working factors of flank lock type precision lock nut, the best sensitivity parameter of friction coefficient of teeth face is surface roughness of cutter, and the best sensitivity parameter of ratio of anti-loose is surface roughness of cutter. For example with dynamic flank lock type precision lock nut, the best sensitivity parameter of ratio of axial force is effective match gap, and the best sensitivity parameter of ratio of anti-loose is effective match gap. In the example with static condition of clasp lock type precision lock nut platform and working variable factor, best sensitive parameter is effective match gap, best sensitive parameter of ratio of anti-loose is working end face. For example with static working variable factors of clasp lock type precision lock nut, the best sensitivity parameter of friction coefficient of teeth face is effective match gap, and the best sensitivity parameter of ratio of anti-loose is working end face. For example with dynamic clasp lock type precision lock nut, the best sensitivity parameter of ratio of axial force is working end face, and the best sensitivity parameter of ratio of anti-loose is working end face. Keywords: Taguchi method, friction coefficient, simulating anneal method. sensitivity analysis