为解决联合收割机脱粒滚筒焊接过程缺乏有效检测手段导致质量差的问题,采用基于激光测距的焊接质量在线检测方法,开发脱粒滚筒焊接过程中滚筒圆柱度及外辐盘焊接垂直度在线检测系统,设计在线检测试验台,通过数据处理实现焊接质量的在线检测与变形报警。试验表明,滚筒圆柱度检测精度达0.059 mm,外辐盘焊接垂直度检测精度达0.023 mm,圆柱度检测最大相对误差为2.17%,垂直度的检测最大误差为1.93%,满足脱粒滚筒在线检测要求,检测效率提高到手工方法的20倍以上。系统的研制保证了大型联合收割机脱粒滚筒焊接质量,对提高联合收割机制造水平、保障作业可靠性有重要意义。
As key parts of a corn and wheat combine harvester, the threshing cylinder is mainly processed with the method of welding. The processing quality of threshing cylinders, including cylindricity and verticality of outer radial discs fixed outside of threshing cylinders, is hard to guarantee. The major problems that the threshing cylinder end faces are radial run-out, which have seriously restricted the effect of threshing and selecting corn or wheat from millet straw. Thus, without online diagnosis method and system, the threshing cylinder of corn and wheat combine harvester will get poor quality. In this paper, the welding quality online detection method based on laser sensors was studied, and the online detection system of cylinder roundness and outer radial disc verticality during the welding was developed, including the threshing cylinder rotation driving system, laser sensor distance detection system, sliding guide rail system and data acquisition and display system. As to cylindricity detection, sliding guide rail that was parallel to the threshing cylinder axis was fixed on the welding platform, a laser distance detection sensor was fixed on the sliding guide rail, and a servo motor was connected to the threshing cylinder axis. While detecting, the threshing cylinder was driven to rotate, and at the same time, the laser sensor was driven to move along the sliding guide rail; and the vertical distance from the sensor to the threshing cylinder was detected, which was collected in real time by the computer. According to the threshing cylinder rotation data and laser sensor sliding track data, the threshing cylinder shape and cylindricity were calculated. As to the inspection of outer radial disc verticality, vertical sliding guide was fixed to the parallel sliding guide rail that was perpendicular to the sliding rail. Install laser sensor on the vertical sliding guide rail and keep the laser beam parallel to threshing cylinder axis. When the threshing cylinder was driven by the motor to rotate, the distance fro