| 摘要 |
PURPOSE:To prevent a crown part from oscillating its neck, by pivotally connecting the crown part of a piston with its skirt part by a piston pin with a clearance forming between oppositely facing parts and adapting bridge parts in a side of the crown part to the skirt part. CONSTITUTION:A crown part 1 provides in its inside a pair of right and left bosses 6, 6 to be extended while legs 10, 10 to be extended from each boss toward a side opposite to the crown part 1, further side ends of each leg 10 are connected with each other by bridge parts 11, 11 partly formed into a circular arc-shape. The bosses 6 are internally fitted between a pair of bosses 7, 7 protrusively provided on the internal surface of a skirt part 2, penetratively stopping a piston pin 3 to be mounted to pin holes 8, 9 provided penetrating through each boss 6, 7. Under this condition, a piston, both forming a clearance C between oppositely facing parts in the peripheral bottom end of the crown part 1 and in the peripheral upper end of the skirt part 2 and adapting the bridge parts 11 to the bottom end internal peripheral surface of the skirt part 2, prevents the crown part 1 from swivelling around the pin 3. |
