| 摘要 |
<p>PURPOSE:To prevent an inferior product from flowing into the next process, by measuring the expansion amount of a concaved parts of which the inner peripheral surface hardening in the diameter direction at the time of hardening on the outer peripheral surface of said parts and comparing the measured expansion amount with a preset reference expansion amount to judge the quantity of the parts. CONSTITUTION:A concaved parts 10 to be hardened is held almost vertically so as to direct the opening part thereof downwardly and a high frequency hardening coil 20 having a jet cooling pipe for hardening mounted therein is inserted into said parts from the opening part thereof. Further, a dial gauge 40 is fixedly provided to the upper surface of a working table 50 and a measuring element 43 is mounted to the leading end of the spindle 42 slid in a stem 41. A current is supplied to the coil 20 and the vicinity of the inner peripheral surface of said parts is locally heated by Joule heat to expand the outer diameter of the parts 10 while hardening effect is judged on the basis of the indication amount of the gauge 40. By this method, total inspection can be performed simultaneously with hardening work and an inferior product is prevented from flowing into the next process even in a full-automatic manufacturing process.</p> |
