VARIABLE LENGTH CONNECTING ROD AND VARIABLE COMPRESSION RATIO INTERNAL COMBUSTION ENGINE

A variable length connecting rod (6) comprises a connecting rod body (31), an eccentric member (32), a hydraulic cylinder (33a), a hydraulic piston (33b), a check valve, a switching mechanism and a hydraulic mechanism.. The check valve permits a flow of hydraulic oil from a primary side of the check valve to a secondary side of the check valve and prohibits the flow from the secondary side to the primary side. The switching mechanism comprises a single switching pin. The connecting rod body is formed with first to fourth oil paths. The switching pin is switched between a first position making the first oil path communicate with the fourth oil path and making the second oil path communicate with the third oil path, and a second position making the first oil path communicate with the third oil path and making the second oil path communicate with the fourth oil path.