| 摘要 |
<p>PURPOSE:To make the amount of thermal expansion around the circumference of each sleeve approximately uniform during the running of an engine by filling under pressure a molten metal into a sleeve to be set on a metal mold in a state of providing a radially expanding force to the sleeve, and removing the force after solidifying the molten metal to provide boring work to the inner circumferential surface of sleeve. CONSTITUTION:A holding cylinder 46 is radially contracted by raising an upper mold 9, separating side molds 101, 102 from each other to open the mold, and lowering an actuation rod 50 with the aid of a hollow piston 52 by actuating a hydraulic cylinder 51 to move a taper part 50a downward. Next, the metal mold M is filled with a molten metal under pressure from the sprue 17 of a lower mold 11; in a state of loosely fitting an approximately round cast-iron sleeve 3 to the cylinder 46 radially expanding the cylinder 46 by actuating the cylinder 51 reversely to said operations, and providing a radially expanding force to the sleeve 3. After the molten metal is solidified, said expanding force is removed to open the mold in order to obtain a stock cylinder block, and then the inner circumferential surface of sleeve 3 is subjected to boring work.</p> |
