Abstract: To solve the problems of low positioning efficiency and high machine occupancy for large thin-walled parts,an off-machine presetting system and application for multi-variety large cylindrical thin-walled parts was proposed that included the off-machine presetting station with its control software.The off-machine presetting station was composed of four-axis measuring equipment,measuring ending (dial indicator or laser scanner) and zero-point positioning fixture,while the control software had the applications of metering data analysis,point cloud analysis and assisted posturing.For cylindrical and conical thin-walled parts,the dial indicator was used with the four-axis measuring equipment to complete the measurement of the pose meter data,and then the attitude adjustment was calculated through the control software,so as to assist the workers to complete the workpiece adjustment.For special-shaped cylinder thin-walled parts,the laser scanner was used to complete the measurement of point cloud data,and then the correction amount of the processing coordinate system was calculated with the point cloud registration method through control software.After completing the position and pose measurement and pre-adjustment of multi-model thin-walled parts on the off-machine presetting workstation,they were quickly transferred to the machine tool by using the zero-point positioning system and processed to complete.Based on this presetting system that had been installed on site,the experimental results showed that the off-machine presetting system could improve the alignment efficiency of cylindrical and conical parts by about 4 times,and improve the alignment efficiency of special-shaped parts by about 0.7 times.At the same time,the equipment had certain versatility,which could provide reference and technical support for the alignment and positioning process of other types of large-scale thin-walled parts in the aerospace manufacturing industry.

Key words: multi-model large cylindrical thin-walled parts, positioning and alignment, off-machine presetting, automatic measurement, point cloud measurement

摘要： 针对大型薄壁件机内找正定位效率低,机床占用率高等问题,依据“机外找正-机内加工”的双工位作业模式,提出并开发了面向多品种大型筒类薄壁件的机外预调系统,主要包含机外预调工作站及其管控软件。机外预调工作站由四轴测量设备、测量末端(百分表或激光扫描仪)和零点定位工装等组成,而管控软件则主要包含打表数据分析、点云数据分析和辅助调姿等功能。对于圆柱、圆锥筒类薄壁件,利用百分表配合四轴测量设备完成其位姿打表数据测量并通过管控软件计算调姿量,辅助工人完成工件调姿。对于异形筒类薄壁件,利用激光扫描仪配合四轴测量设备完成测量获取点云数据,进而通过管控软件利用点云配准手段计算加工坐标系的修正量。在机外预调工作站上完成多品种薄壁件位姿测量及预调后,利用零点定位系统将其快速转运至机床内部完成加工。在某型武器中的三类典型筒类薄壁件进行了机外预调应用验证,结果表明机外预调系统可提高圆柱、圆锥类零件找正效率约4倍,提高异形类零件找正效率约0.7倍。同时,该设备具备一定的通用性,可为航空航天制造业中其他类型的大型薄壁件找正定位过程提供参考及技术支持。

关键词: 多品种大型筒类薄壁件, 定位找正, 机外预调, 自动打表测量, 点云测量