Four-stroke engine
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorYoshihiko Takeuchi
Life of this patent
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Abstract
A four-stroke engine includes a cylinder block, a cylinder head mounted on the cylinder block, multiple cooling fins formed on the cylinder block and the cylinder head, a combustion chamber and an intake port and exhaust port formed in the cylinder head and in communication with the combustion chamber. A cooling jacket is formed in the cylinder head only between a virtual object generated by the intake port or exhaust port being rotated about a cylinder axis. A mating surface of the cylinder head on the cylinder block.
Claims14
A four-stroke engine comprising:
- a cylinder block;
- a cylinder head mounted on the cylinder block;
- multiple cooling fins formed on the cylinder block and the cylinder head;
- a combustion chamber;
- and
- an intake port and exhaust port formed in the cylinder head and in communication with the combustion chamber,
- wherein a cooling jacket is formed in the cylinder head only between a virtual object generated by the intake port or exhaust port being rotated about a cylinder axis, and a mating surface of the cylinder head on the cylinder block,
- the cooling jacket being formed only between a bottom surface of the exhaust port and the mating surface on the cylinder block, and surrounding an outer peripheral portion of the combustion chamber viewed in a cylinder axis direction, and
- wherein the cooling jacket comprises a cooling water supply port and a cooling water discharge port that are disposed in direct opposition to each other when viewed in the cylinder axis direction.
A four-stroke engine comprising:
- a cylinder block;
- a cylinder head mounted on the cylinder block;
- a combustion chamber;
- an intake port and exhaust port formed in the cylinder head and in communication with the combustion chamber,
- a cooling jacket formed only between a bottom surface of the exhaust port and a mating surface on the cylinder block, and surrounding an outer peripheral portion of the combustion chamber viewed in a cylinder axis direction, wherein the cooling jacket comprises a cooling water supply port and a cooling water discharge port that are disposed in direct opposition to each other when viewed in the cylinder axis direction;
- a radiator;
- and
- circulating cooling water between the cooling jacket and the radiator,
- wherein a mechanical pump driven for rotation by a crankshaft circulates the cooling water between the cooling jacket and the radiator during an engine operation, and a motor-driven pump circulates the cooling water in the cooling jacket for a given time at a time the engine stops.
A method for manufacturing a four-stroke engine, comprising:
- providing a cylinder block, a cylinder head mounted on the cylinder block and a combustion chamber;
- forming an exhaust port in the cylinder head in communication with the combustion chamber;
- providing a cooling jacket and radiator;
- surrounding an outer peripheral portion of the combustion chamber with the cooling jacket and disposing the cooling jacket entirely between a bottom surface of the exhaust port and a mating surface of the cylinder block, wherein the cooling jacket comprises a cooling water supply port and a cooling water discharge port that are disposed in direct opposition to each other when viewed in the cylinder axis direction;
- circulating cooling water between the cooling jacket and the radiator;
- driving a mechanical pump for rotation by a crankshaft circulating the cooling water between the cooling jacket and the radiator during an engine operation;
- and
- circulating the cooling water in the cooling jacket for a given time at a time the engine stops.
Dependencies are inferred from the claim text.