| 摘要 |
PURPOSE:To eliminate the need for normalizing of blank materials and to harden the materials with less bulging near the end faces, by hardening the crawler belt pins heated to prescribed temp. under spraying of high pressure water while rotating the same, and spraying air to both end faces. CONSTITUTION:A crawler belt pin A of medium carbon steel constituting an endless track vehicle of such as bulldozer is heated over the entire part to a hardening temp. and is then placed on a roll 2 of a rolling press device A. While the pin is rotated under pressure with a pressurizing roll 2', the pin is hardened with the air sprayed from an air spray 3 on both end faces 1a under spraying of high pressure water over the entire part with a high-pressure water spray having large cooling capacity. The air spray 3 is constituted in the way wherein a rotating body 5 having a recess 7 is supported in the small diameter part 4a of a body 4 through a thrust bearing 6, the outside circumferential wall 7a at the tip formed with the notch 9 of the recess 7 is brought into press contact with the face 1a, and air is supplied through a hole 8 opened in the recess 7 from an air source 10 communicating with the same. |
