| 摘要 |
A precision cast connecting rod which has an elongate tubular shank member defining a hollow section for producing desired stiffness to weight characteristics. Piston and crankpin connecting members are attached to opposite ends of the shank member. The connecting members are provided with passages which extend axially therewithin from the hollow section. Defined within the elongate tubular shank member is a radially extending central aperture. A precision casting method for preparing the hollow connecting rod includes forming an elongate core with a locating member positioned at each end thereof and a disk-shaped protuberance extending radially therefrom. The core is secured in a die and defines a cavity therebetween for preparing a pattern of the connecting rod using a molding material which substantially encapsulates the core within the cavity. After removing the pattern from the die, coatings of refractory material are applied to form a shell mold which encrusts the pattern. Removal of the molding material results from heating the shell mold. The connecting rod is formed by filling the cavity with molten metal and then cooling the shell mold. Unwanted material is eliminated from the connecting rod by separating the shell mold from the solidified metal and removing the core from the hollow section, thereby producing a near net shape of the connecting rod.
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