A precision three-dimensional image measurement technique of high-temperature forging and the Near-Net-Shape of forging process

发电机铁芯、船舶、钢铁制造等用的大型钢锻件，先用大型自由锻压机加工，再用机加工完成。为了保证物体的正确成品尺寸，在锻造过程中有必要增加尺寸余量。我们希望使这个余量尽可能小，以减少原材料的使用量和加工的功率消耗。为此，有必要在锻造过程中测量锻造部件的尺寸，如轴倾斜，弯曲和截面形状。然而，由于锻造对象的温度高，其尺寸大，测量其尺寸可能是非常困难的。在本研究中，提出了各种技术。这些技术包括多光谱图像分析技术、温度分布测量误差削减技术、多相机大尺寸体三维测量技术和锻件提取技术。利用该技术，可以在短时间内实现高温（约800-1200℃）、大尺寸（长约10m，直径约1-3m）锻件的高精度测量。基于所提出的技术开发了一个仪器系统。我们目前正在一家工厂实施测量系统。注：日本铸造公司研究员上野正硕先生于2005年退休，该公司的两位研究伙伴Kuwaki toru先生和Oshikawa takumi先生接替了上野先生安排的研究内容，并顺利完成。

The large steel forgings used for generator cores, marine vessels, steel manufacture, etc. are first processed using a large free forging press, and are then finished by machining. In order to ensure the correct finished size of the object, it is necessary to add a size margin in the forging process. It is desirable to make this margin as small as possible so as to reduce the amount of raw material used and the power consumption of machining. For this reason, it is necessary to measure the dimensions of forging components, such as the shaft slant, the bend and the cross-sectional shape, at the time of the forging process. However, since the temperature of the forging objects temperature is high and its size is large, measuring its dimensions can be very difficult to perform.In this study, various techniques are proposed. These include a multi-spectral image-analysis technique, a measurement error cutback technique by temperature distribution, a large-sized body three-dimensional measuring technique using a multi-camera and a forging object extraction technique. By using the proposed techniques, measurement of a high temperature (about 800-1200℃) and large size (it has a length of approximately 10m and a diameter of approximately 1-3m) forging object is realized in a short time and to high accuracy.An instrumentation system based on the proposed technology has been developed. We are currently working to implement the measurement system in a factory.Notes : Investigator Mr.Masakatsu Ueno of Japan Casting & Forging Corporation retired with 2005, two research partnership people, Mr.Toru Kuwaki and Mr.Takumi Oshikawa of the corporation took over of the research contents of the schedule assigned to Mr.Ueno, and they were completed favorably.