| 摘要 |
PURPOSE:To grind a bead precisely according to a step by detecting the position of the bead by potentiometer devices, as well as detecting the step at the joint of a grinding object pipe, and inclining a grinding tool according to the detected step. CONSTITUTION:A region between both turning angle positions is made into bead width, and a turning angle position located at the center of the bead width is positioned in an intermediate position between both potentiometer devices 11, 12, thus positioning a bead 9 into the intermediate position between both potentiometer devices 11, 12. The reason why difference in value is generated to the distance between a head part 8 and the inner peripheral surface of a grinding object pipe 1 measured by both potentiometer devices 11, 12 is because a step exists at the joint of the grinding object pipe 1, and therefore the grinding object pipe 1 is not a complete circle, as well as the difference in value corresponds to the size of the step. Accordingly, one side of a grinding tool 10 is placed closer to the inner peripheral surface of the grinding object pipe compared to the other side according to the difference in value. Thus inclining the grinding tool, the bead can be ground precisely according to the step. |
