固定負荷下金屬線材端部無模抽製成形製程研究

Study on Dieless Drawing to Form a Metal Wire End under Constant Force

范光堯(Kuang-Jau Fann) ； 王俊凱(Chun-Kai Wang)

《鍛造》 25卷3期 (2016/10) Pp. 16-22

摘要

金屬棒線材於端部加工時，多採型鍛冷作，致令噪音橫生、模具易損，因此本研究嘗試建立一抽製製程，以製出金屬線材端部幾何。該製程承襲應用局部加溫與冷卻，取代模具以產製金屬管線材的無模具抽製製程，在給予金屬線材適切的溫度分布下，以固定軸向負荷抽製出端部幾何。本研究依所欲成形的金屬線材端部幾何，得出其應變分布，配合所設定的拉伸負荷，得出應力分布後，再依金屬線材於不同溫度的成形特性曲線，得出成該溫度分布。為使金屬線材能抽製成形端部，在金屬線材中段先行集中加熱形成鐘形溫度分布後，始行抽製，以令線材於該處頸縮。其後在抽製過程中於初始出現溫度峰值處加以冷卻，並令抽製結束時實現該溫度分布，以得出所欲成形的端部幾何。本研究以線徑5mm的S45C中碳鋼線材抽製出具錐度0.3的幾何端部為例，在提供負荷設為2,500N時所計算得出的溫度分布下，均能得出該端部幾何，證實本研究所提金屬線材端部無模抽製成形製程的可行性。

關鍵字

無模抽製製程 ； 金屬線材 ； 抽製

並列摘要

Using swaging to cold form the end of metal wires makes noises and causes die to wear as well. Thus, this study tried to create drawing process to form the end of metal wires. This process is based on the dieless drawing process, which adopts local heating and cooling instead of die to produce metal wires or tubes. By giving adequate temperature distribution, the end of metal wires is formed under a constant axial force. This study calculates the strain distribution according the geometry of wire end to be formed. For a given drawing force, the stress distribution is then determined. By comparing the stress-strain curve created by combining the strain and stress distributions, to the stress-strain curves of the wire material at different temperature, the temperature distribution of the wire end can then be found. To form the end of metal wires, the middle part of wires should first be heated to have a bell shape temperature distribution, so that the wire can be necked there, once the drawing force is applied. After starting drawing, the wire should be locally cooled down there, so that at the end of drawing process the calculated temperature distribution can be achieved and the end of wire can be formed to the given shape. As an example, a S45C middle carbon steel wire of 5 mm in diameter is formed to have a taper of 0.3 at its end. The taper was formed by drawing the wire under the given axial load 2,500 N along with the temperature distributions, which shows the feasibility of the dieless drawing process initiated by this study.

並列關鍵字

Dieless drawing ； Metal Wire ； Drawing