Thermal Stress Analysis for Nd:YAG Laser Welding of High Precision Solenoid Valves in Hydraulic Systems

• Main Authors: Wu Jia-Da, 吳佳達
• Other Authors: Chang Chin-Lung
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/21360385930952740677

碩士 === 國立屏東科技大學 === 車輛工程系所 === 95 === In the manufacturing process of laser welding of high precision solenoid valves in hydraulic systems, cracks will occur at the sleeve due to a large thermal stress during welding. This study investigated into the above-mentioned problem by changing the pulse repetition frequency, overlap ratio of spot, pulse duration and welding position. The simulation results showed that the thermal stress will be reduced by increasing the preheating effect deduced by increasing the pulse repetition frequency, overlap ratio of spot, pulse duration. When welding position is nearer the bottom of sleeve, a large thermal stress will be caused because of severe temperature variation. On the contrary, when welding position is farther form the bottom of sleeve, the thermal stress will be reduced significantly, and avoid occurring the crack during welding.