| 摘要 |
PURPOSE:To improve the durability of the piston by a method wherein the crown section of the piston, being provided with a squash lip at the peripheral rim of the opening of a cavity formed on the crown section of the piston, is provided with a cooling path so as to enclose the cavity. CONSTITUTION:The crown section 2 of the piston 1 is formed with a circular cavity 13 and the squash lip 5, protruded inwardly from the periphery of the opening in the radial direction and consisting of a fiber reinforced aluminum alloy, is engaged with and fixed to the opening of the cavity 3. The crown section 2 is formed with the annular cooling path 8 so as to encircle the cavity 3 and supply cooling oil from oil jets (not shown in the diagram). This cooling path 8 is formed by casting pipe members by pouring molten material from an introducing part 8A, bored vertically onto a pin boss or the like, a recirculating part 8B and a discharging part (not shown in the diagram). Further, the upper and lower surfaces of the squash lip 5 are formed by horizontal surfaces and the whole of the lip 5 is made into a thin configuration. |
