An analysis of forming for a rivet nut

• Main Authors: Quan-En Lu, 呂權恩
• Other Authors: Heng-Sheng Lin
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/hzgvf6

碩士 === 國立高雄應用科技大學 === 模具系碩士在職專班 === 102 === A rivet nut is made by steps on the cold forging machine. Differed by tooling design, there are 5-6 steps to complete. By close-cut cutting die on the manufacturing machine, the cutting blank is shorter and distortion is relatively high. First step is to straighten blank. Second and third steps are to locate the T-Nut inner hole and outer shape. The current industry is generally taking quasi-experimental research method to design the tooling. When the fourth and fifth steps fail to achieve the fullness of teeth and the dimension of outer shape, the product will be taken as a fault. The current study is conducted by General-purpose finite element software to simulate the process and discover the workable design. This research is conducted by Try and Error method and research on 5 types of forging process. It is to explore the pre-form method on the 3rd step to improve the fullness of the teeth. The results show that the chamfer on the third step of the proposal 1 and 2 will improve the fullness of the teeth for the fourth step. However, the flange size is not able to achieve. In the proposal 3, the close-cut blank was change to be forged by squeezing packing method. This will exclude the chamfer parameter and it reaches both the fullness of the teeth and the forging dimension. Although the fullness of the teeth is shown improved in proposal 4, the flange surface leaves the teeth scar and is not acceptable. The simulation is as the optimum method to make the cold forging tooling and put it in practice to verify the size. On the process of designing the tooling, it is effectively able to save the time and cost. It is further expected to improve the fullness of the teeth on the a rivet nut.