UPPER LINK ON MULTI-LINK TYPE PISTON CRANK MECHANISM OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To lubricate between a pin boss part 23 for an upper pin and the upper pin 4 by using oil mist scattered in a crank case.;SOLUTION: A multi-link type piston crank mechanism of an internal combustion engine is composed of an upper link 3, a lower link 6 and a control link 7. The upper link 3 and the lower link 6 are connected via an upper pin 4. A pin boss part 23 for upper pin to which the upper pin 4 is rotatably fitted is provided with a pair of oil mist collecting concave parts 28 on each end face 24. The oil mist collecting concave part 28 allows a depth in an upper pin 4 shaft direction to be shallow on an upper end part 28a of the piston 1 side and to be gradually deeper as nearer to the lower end part 28b. Oil mist is collected in accordance with vertical movement of the upper link 3 and is guided to the inner circumferential side.;SELECTED DRAWING: Figure 6;COPYRIGHT: (C)2019,JPO&INPIT