| 摘要 |
PURPOSE:To enable to judge the propriety of the insulating property of the slot of a squirrel-cage rotor before die casting by temporarily filling low melting point metal in the slot when judging the propriety and employing a probe magnetic core having an exciting coil. CONSTITUTION:A slot is insulated, a squirrel-cage rotor 2 before aluminum die casting is secured between a pressing jig 7 and a retainer 8, metal 6 which is melted at 100 deg.C or lower such as alloy of tin, lead is heated by a heater 10, and press filled to the slot 3 and an end ring 1b by the operation of a plunger 11. Then, two testing probe cores 4, 5 having exciting coil are contacted with the surface of the rotor to give magnetic flux, the insulation of the slot 3 is tested, and the metal 6 is then removed. Accordingly, the improper insulation can be detected before aluminum die casting, thereby eliminating the loss of material and time. |
