| 摘要 |
PURPOSE:To obtain a large moment of inertia, increase the strength of a crankshaft installation hole, facilitate machining and cut cost, by soft nitriding treating trigger poles which are welding-fixed onto the rim part of a rotor and the rotor body. CONSTITUTION:The thickness of a rim part 21c is made to be sufficient to provide a necessary moment of inertia for a rotor 20c, and two trigger poles 22a and 22b which are formed by cutting a cold-pressed steel plate having a prescribed thickness into paper-strip form and bending said steel plate along the outer peripheral surface are welding-fixed onto the outer peripheral surface of the rim part 21c. After the trigger poles 22a and 22b are welded onto the rotor body 21, these members 21, 22a, and 22b are soft-nitriding-treated, and all the surface including the inner surface of a tapered hole 21d is hardened. Therefore, the moment of inertia of the rotor 20 can be increased, and since the material is low-carbon steel, turning work is facilitated, and trigger poles can be easily welded onto the outer peripheral surface of the rim. Further, since the soft nitriding treatment generates little stress, correcting machining is hardly necessitated, and production cost can be cut. Further, the strength of the installation hole onto a crankshaft can be increased. |
