Four-cycle internal combustion engine
AssigneeKawasaki Jukogyo Kabushika Kaisha
InventorsTadao Yashirodai, Kazuhiko Takemoto
Life of this patent
Estimating the term…
Abstract
To provide a four-cycle combustion engine wherein the air-fuel mixture can be smoothly passed at all times by the utilization of the reciprocating motion of the piston to effectively lubricate the valve operating mechanism and the cranking mechanism and also to allow the air-fuel mixture to be supplied into the combustion chamber with a high suction efficiency. By utilization of the reciprocating motion of the piston (9), a portion of the air-fuel mixture (M) fed from the intake passage (33) is circulated through a circulating passage made up of the valve chamber (18), the first passage (24), the crankcase chamber (7) and the second passage (41).
Claims11
A four-cycle combustion engine which comprises:
- a valve operating mechanism including a valve drive unit mounted on a cylinder head for driving intake and exhaust valves, and a drive transmitting unit for transmitting a rotary drive of a crankshaft, drivingly coupled with a piston, to the valve drive unit;
- a valve chamber accommodating therein the valve drive unit and communicated with an intake port capable of being selectively opened or closed by the intake valve;
- an intake passage for introducing into the valve chamber an air-fuel mixture containing lubricant oil;
- a first passage accommodating therein the drive transmitting unit and communicating between the valve chamber and a crankcase chamber;
- and
- a second passage communicating between the crankcase chamber and the valve chamber;
- wherein said valve chamber, said first passage, said crankcase chamber and said second passage cooperate with each other to define a circulating passage through which a portion of the air-fuel mixture from the intake passage is circulated as a result of a reciprocating motion of the piston.
Dependencies are inferred from the claim text.