| 摘要 |
PURPOSE:To obtain a crank throw high in accuracy and excellent in quality by providing the weight distribution coefficient of each part of a stock so that it satisfies a specified condition. CONSTITUTION:The weight of the small diameter part 2 of the stock is taken for a stock pin part weight WPS and the sum total of the weight of a tapered part 3 and the weight of one half part from the stock center of a flange part 4 is taken for a stock top part weight WTS. The weight of the residual one half of the flange part 4 is taken for a stock bottom part weight WBC and the weight of a crank throw pin part 6 is taken for a throw pin part weight WPC. Further, the weight of the part on the pin side from a position to the center of the stock of an arm part 7 is taken for a throw top part weight WTC and the weight of the residual part of the arm part is taken for a throw bottom part weight WBC. A pin part weight distribution coefficient RP, an arm bottom part weight distribution coefficient RB and an arm top part weight distribution coefficient Rgamma are provided to satisfy the inequalities.
|
