| 摘要 |
PURPOSE:To improve the cooling effect on the top of a piston and recover oil smoothly by inclining a cavity in the back of the top of the piston such that the center side of piston is in the upper position and the peripheral end side in the lower position to open oil holes inclined downward. CONSTITUTION:The top 11 of a piston 10 is formed in the back with a cavity 12. The cavity 12 is formed slantly such that the ceiling 13 and the bottom 14 have respectively the piston center side on the upper position and the peripheral end on the lower position. The bottom 14 is provided with an oil supply hole 16 and an oil exhaust hole 17 in the neiborhood of the peripheral end. An oil hole 20 is provided from an oil ring groove 19 on the outer peripheral surface of the piston slantly downward to the interior of the piston 10. Thus, when vertical acceleration is applied to the piston, oil in the cavity 10 moves along the ceiling 13 and bottom 14 while being recovered from the oil ring groove through the oil hole 20 smoothly. |
