BARREL GRINDING METHOD, BARREL GRINDING DEVICE AND BARREL JAR

Japanese Patent JP3758557

B2

PROBLEM TO BE SOLVED: To restrict the injection of the mass when opening a barrel jar after grinding. SOLUTION: A cover 13 of the barrel jar 10 is provided with a valve device 20 for controlling a flow of the air between inside and outside of the barrel jar 10. A pressure reducing device 30 having a vacuum pump 32 can be connected to the valve device 20. When the vacuum pump 30 is operated after connecting the pressure reducing device 20 to the valve device 20 and opening the valve device 20 thereafter in a stage before the grinding work, the air inside of the barrel jar 10 is sucked to reduce the pressure inside of the barrel jar 10. After the pressure reducing work is concluded, the valve device 20 is closed to maintain the inside of the barrel jar 10 in the pressure reduced condition, and grinding is performed. The mass M and the air inside of the barrel jar 10 are warmed by the frictional heat generated in a grinding process, and the pressure inside of the barrel jar 10 rises, but the pressure inside of the barrel jar 10 is reduced before the grinding work, injection of the mass M inside of the barrel jar can be restricted when opening the cover 13 after the grinding.