トーチろう付けにおけるろう溶融域のインプロセス画像計測技術の開発

Abstract

Skilled workers control the braze filler metal supply while simultaneously monitoring the formation of a metal molten area. This ensures high-reliability brazing of workpieces engaged in various states. In order to emulate the technique of skilled workers', an image processing method that monitors the formation of a metal molten area using a CCD camera is proposed. This method makes use of the fact that brazing is inevitably conducted in a reducing atmosphere. In a reducing atmosphere, the surface of a molten braze filler metal becomes a mirror having a high regular reflectance. A band pass filter and a light source so as to eliminate the burner flame light and infrared radiation light from the workpiece surfaces optically as interference lights in order to receive only the regular reflected light from the molten area were selected. The proposed method was applied to the automatic torch brazing of copper pipes in order to experimentally verify its effectiveness for high-reliability brazing.