| 摘要 |
PURPOSE:To harden the entire surface of steel balls for grinding to uniform hardiness by heating said balls then cooling the same while allowing the balls to roll down spirally by each piece in a cooling vessel. CONSTITUTION:A bucket 3 contg. a large number of steel balls 4 is conveyed on rails 2, and is passed through a heating furnace, whereby the balls are heated to prescribed solubilizing treatment temps. The bucket 3 out from the furnace 1 balls down, and the high temp. balls 4 in the inside drop into a hopper 6. Next, the balls 4 enter the inside of a cooling vessel 5 below, from the hopper 6, and roll down by each piece on a spiral slide table 7. En route of this, they are uniformly and quickly cooled by the mists from multiple mist ejection ports 8 provided on the inside circumferential wall of the vessel 5 and the cooling wind from the air ejection port 9 provided in the bottom part of the vessel 5. The balls for grinding formed with uniform guench hardened layers over the entire surface of the balls are mass produced with high productivity. |
