针对在机床上半精加工状态的大型工件进行在线超声波探伤的需要, 考虑工件外形存在的不圆度、锥度等形面误差对超声波探头接触间隙稳定性的影响, 提出一种基于改进Cardan悬架的型面变化自适应跟踪机构的设计方案。分析了跟踪扫查机理, 设计了能自动适应大型回转体局部形状变化情况的扫查跟踪装置, 使超声波始终沿工件法线方向入射, 实现了回转体在加工同时的在线探伤。结合所开发的大型回转体超声波检测软件系统, 基本实现了大型回转体在机床加工过程中在线自动超声探伤的需要。实际应用结果表明, 开发的系统对于提高大型回转件检测质量和效率有较好的作用。

Aiming at the requirement of online ultrasonic testing for large scale semifinishing workpiece and considering the influence of its surface contour error(such as out-of-roundness, conicity) on stabilization of the clearance between the probe and the workpiece, the design plan of adaptive surface shape tracking scanner based on ameliorated Cardan device was advanced and the mechanism analysis of the scanner was performed, and a novel scanner whose posture was adaptable to the specific partial condition of the large scale rotational part was developed. The scanner made the ultrasonic wave transmit into the rotational part along with the normal direction of the detecting surface so as to realize online ultrasonic flaw detection for large scale rotational parts. By the combination of the scanner and the large scale rotor online ultrasonic detection system, a software system was developed, which realized the requirement of online ultrasonic testing process and machine process run synchronously. The practical application proved the developed system elevated the ultrasonic testing quality and efficiency of large scale rotational parts.