chapter 11 焊接新技术及相关技术2012.ppt

Characteristics of robot arc weld sequencing A major concern for weld sequencing is productivity, as well as the fine quality of weldments. Therefore, there is a need for compromise between productivity and quality In order to improve weld robustness, multi-pass welding is used in thick-walled construction, as well as in aluminum alloy welded construction. By using multi-pass welding, tensile residual stress and brittle fracture resistance can be reduced. * A typical process planning composed of such stages as welding task sequencing, multi-pass planning, collision-- free path planning, welding operation planning including a weld schedule, robot and positioner motion planning, weld seam tracking, and calibration of the robot arms and workcells * * * Plasma-arc cutting requires directcurrent power, supplied by sources rated at 400-V open circuit and 200-V under load for heavy cutting. The power-supply circuit resembles that used for gas-tungsten-arc-welding power supplies Air plasma, a viable low-cost alternative, to cut stainless steel or aluminum. Portable air-plasma cutting units that run on line power-rated 15- to 150-A capacity-cut steel up to 2 in. thick, leaving edges clean 第11章: 焊接新技术及相关技术 * * Air-Plasma-Arc-Cutting 第11章: 焊接新技术及相关技术 * * 第11章: 焊接新技术及相关技术 * * 4)Laser Beam Cutting Types of Lasers for Metal Cutting CO2 Lasers Cutting The theory on which a CO2 laser operates is fairly simple. Place a volume of CO2 gas, usually mixed with helium and nitrogen, in between two reflective mirrors, pump electrical energy into it (via either radio frequency (RF) or direct current (DC) discharge), and as the CO2 gas atoms absorb the electrical energy they become excited causing them to give off photons of light. 第11章: 焊接新技术及相关技术 * * Solid State Lasers Cutting A solid-state laser describes an optically pure material doped with specific elements that will work when high intensity light is applied to them. The most common material, neodymium-