To prevent abrasion or the like due to local deformation at end portions of a crankpin bearing surface 31 of a lower link 13.
The lower link 13 comprises separate members such as a crankpin bearing member 21 and connection pin bearing members 22, 23. The crankpin bearing member 21 is formed with the crankpin bearing surface 31 through which a crankpin passes. The connection pin bearing members 22, 23 are each provided with a first connection pin bearing surface 41 through which a first connection pin for connection of an upper link passes and a second connection pin bearing surface 42 through which a second connection pin for connection of a control link passes. The connection pin bearing members 22, 23 are provided on both sides of the crankpin bearing member 21 and they are united to one another by means of bolts 24, 25 for the bearing members. Both end portions of the crankpin bearing surface 31 project as cylindrical portions 32. Load from the crankpin bearing member 21 is not transmitted to both the end portions directly so that deformation thereof is prevented.
MOGI KATSUYA
HIYOSHI RYOSUKE
AOYAMA SHUNICHI
Next Patent: INCLINED CYLINDER TYPE MULTIPURPOSE FOUR-CYCLE ENGINE