鋁合金燃油濾清器雷射銲接封裝過程之熱應力分析

Thermal Stress Analysis for Nd:YAG Laser Welding of Aluminum Alloy Fuel Filter

柯政佑(Cheng-Yu Ke)

指導教授 ： 張金龍 博士

國立屏東科技大學/工學院/車輛工程系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00235

摘要

雷射光束特有的高功率密度與高精密度特性，於近幾年來被用來對精密元進件進行銲接構裝工作。由於近幾年來汽車輕量化的需求而使得許多車體零件都採用鋁合金來製造以達到省油的目的。鋁合金燃油濾清器也是其中的一項重要元件，而在封裝製程中常遭遇到濾清器本體與密封蓋的銲接封裝技術的問題。若考慮以Nd:YAG雷射銲接技術，藉助於其較小的熱影響區特性，將有可能避免發生熱裂紋的發生。此外，利用對接、疊銲或角銲方式來進行兩工件的銲接過程時，必須要考慮到鋁合金燃油濾清器油內的高壓狀態，若以慣用的點銲方式來進行雷射封裝製程，將無法克服滲油的問題，因此必須考慮以連續繞銲方式來加以進行。因此本研究就是要以數值模擬方式同時探討以脈衝式Nd:YAG雷射來對鋁合金燃油濾清器進行銲接封裝工作。模擬結果顯示，提升雷射脈衝寬度、脈衝頻率以及光斑重疊率，濾清器會因預熱效果的提升而降低在銲接時所產生的熱應力。

關鍵字

雷射銲接 ； 燃油濾清器 ； 熱應力

並列摘要

The laser beam characterized by high power density and high precision has been used in laser welding of packaging for many high precision parts in recent years. Due to the demand for light-weighted automobile, aluminum alloy has been used to manufacture the vehicle parts to reach the goal of economizing oil. The aluminum alloy fuel filter is also the important one of vehicle parts. The main problem often occurred in packaging of the fuel filter is attributed to the welding technique between the sleeve and the seal cover that ensures a perfect seal. Since the laser welding technique produces a relatively small heat affected zone, it is possible that the thermal crack phenomena induced by thermal stress in packaging of fuel filter could be avoided. Moreover, the high oil pressure in the fuel filter should be taken into account in the laser welding process when the work pieces joint in different ways such as butt, overlap or fillet. When the packaging is operated with spot welding, the problem on oil leakage will arise. Hence, laser welding in continuous way along the sleeve surface will be performed to strengthen the welding. Accordingly, this research will numerically investigate the problem of thermal stress in the packaging for the aluminum alloy fuel filter welded using pulse Nd:YAG laser. Based on the analysis, optimized values of these parameters will be proposed. The simulation results show that the thermal stress of the fuel filter will be decreased due to the preheat effect with a higher laser pulse width and spot overlapping rate.

並列關鍵字

laser welding ； fuel filter ； thermal stress

參考文獻

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