Cooling structure of internal combustion engine

Patent metadata

Field	Value
Publication number	US-10107171-B2
Application number	US-201514977638-A
Country	US
Kind code	B2
Filing date	Dec 22, 2015
Priority date	Dec 24, 2014
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A cooling structure of an internal combustion engine includes a cylinder block, an inner-block coolant passage, a cylinder head, and an inner-head coolant passage. In the cylinder block, cylinders are provided in a row in a cylinder row direction. The inner-head coolant passage is provided in the cylinder head and includes a main coolant passage, an upper exhaust side coolant passage, and a lower exhaust side coolant passage. The main coolant passage is provided above combustion chambers and extends in the cylinder row direction so that a coolant flows into the main coolant passage from the inner-block coolant passage at a first end side of the cylinder head in the cylinder row direction and so that the coolant flows out from the main coolant passage at a second end side of the cylinder head opposite to the first end side in the cylinder row direction.

First claim

What is claimed is:

1. A cooling structure of an internal combustion engine, comprising:
a cylinder block in which a plurality of cylinders are formed in a row, the cylinder block having an inner-block coolant passage formed along an outer periphery of the plurality of cylinders; and
a cylinder head that is fastened to an upper portion of the cylinder block so as to form combustion chambers between top faces of pistons that slide inside the cylinders, an inner-head coolant passage being formed in the cylinder head, wherein
a plurality of intake ports each having an upstream end that opens in one lateral side of the cylinder head and a downstream end that is open to a corresponding one of the combustion chambers, a plurality of exhaust ports each having an upstream end that opens to a corresponding one of the combustion chambers, and an exhaust collection portion that merges the plurality of exhaust ports and that has an exhaust outlet open in another lateral side of the cylinder head are formed in the cylinder head,
the inner-head coolant passage includes a main coolant passage formed in a portion above the combustion chambers, and a pair of upper and lower exhaust side coolant passages that are formed so as to interpose the exhaust collection portion in the cylinder head,
the main coolant passage, and the pair of upper and lower exhaust side coolant passages are separated from each other,
the main coolant passage circulates a coolant in a unidirectional manner such that the coolant flows from the inner-block coolant passage into one end side in a cylinder row direction and out from another end side in the cylinder row direction, and
the pair of upper and lower exhaust side coolant passages circulate the coolant such that the coolant flows first from the inner-block coolant passage into one of the exhaust side coolant passages at the another end side in the cylinder row direction, subsequently circulates from the one of the exhaust side coolant passages to an other one of the exhaust side coolant passages at the one end side in the cylinder row direction, and subsequently flows out from the other one of the exhaust side coolant passages at the another end side in the cylinder row direction.

2. The cooling structure of an internal combustion engine according to claim 1 , wherein
the pair of upper and lower exhaust side coolant passages makes the coolant flow into a lower exhaust side coolant passage of the exhaust side coolant passages from the inner-block coolant passage and makes the coolant flow out from an upper exhaust side coolant passage of the exhaust side coolant passages.

3. The cooling structure of an internal combustion engine according to claim 1 , wherein
a coolant outlet port of the main coolant passage, a coolant outlet port of the pair of upper and lower exhaust side coolant passages, and a coolant inlet port of the inner-block coolant passage are, with respect to the cylinders, open on a same side in a direction orthogonal to the cylinder row direction.

4. The cooling structure of an internal combustion engine according to claim 1 , wherein
in a state in which the internal combustion engine is mounted, the main coolant passage includes an air bleeding passage that extends in the cylinder row direction at a position that is highest in the main coolant passage.

5. The cooling structure of an internal combustion engine according to claim 1 , wherein
in a state in which the internal combustion engine is mounted, an upper exhaust side coolant passage of the exhaust side coolant passages includes an air bleeding passage that extends in the cylinder row direction at a position that is highest in the pair of upper and lower exhaust side coolant passages.

6. The cooling structure of an internal combustion engine according to claim 1 , wherein
in a state in which the internal combustion engine is mounted, an air bleeding passage that is in communication with an upper exhaust side coolant passage of the exhaust side coolant passages is formed at a position that is highest in a lower exhaust side coolant passage of the exhaust side coolant passages.

7. The cooling structure of an internal combustion engine according to claim 1 , wherein
a coolant outlet port of the main coolant passage, and a coolant outlet port of the pair of upper and lower exhaust side coolant passages intersect each other when viewed in the cylinder row direction.

8. The cooling structure of an internal combustion engine according to claim 1 , wherein
in the cylinder head, exhaust ports are formed such that two exhaust ports are open to each combustion chamber, and a plurality of exhaust valve guide portions that support exhaust valves that open and close connection portions between the exhaust ports and the combustion chambers are formed, an upper exhaust side coolant passage of the exhaust side coolant passages is formed so as to surround the plurality of exhaust valve guide portions individually and includes a main passage that is formed on the another lateral side of the cylinder head with respect to the plurality of exhaust valve guide portions, an end portion passage that is formed so as to extend in the cylinder row direction and on the one lateral side of the cylinder head with respect to the plurality of exhaust valve guide portions, and a plurality of communication passages that communicate the main passage and the end portion passage to each other, and
in each cylinder, a cross-sectional area of a portion of the end portion passage that is in contact with an exhaust valve guide portion of the exhaust valve guide portions that is positioned on an upstream side of the coolant is larger than a cross-sectional area of a portion of the end portion passage that is in contact with an exhaust valve guide portion of the exhaust valve guide portions that is positioned on a downstream side.

9. The cooling structure of an internal combustion engine according to claim 8 , wherein
in each cylinder, the end portion passage includes a contraction at a portion in contact with the exhaust valve guide portion of the exhaust valve guide portions that is positioned on the upstream side of the coolant.

10. A cooling structure of an internal combustion engine, comprising: a cylinder block in which a plurality of cylinders are formed in a row, the cylinder block having an inner-block coolant passage formed along an outer periphery of the plurality of cylinders; and a cylinder head that is fastened to an upper portion of the cylinder block so as to form combustion chambers between top faces of pistons that slide inside the cylinders, an inner-head coolant passage being formed in the cylinder head, wherein
a plurality of intake ports each having an upstream end that opens in one lateral side of the cylinder head and a downstream end that is open to a corresponding one of the combustion chambers, a plurality of exhaust ports, two upstream ends of the plurality of exhaust ports being open to each combustion chamber, an exhaust collection portion that merges the plurality of exhaust ports and that has an exhaust outlet open in another lateral side of the cylinder head, and a plurality of exhaust valve guide portions that support exhaust valves that open and close connection portions between the exhaust ports and the combustion chambers are formed in the cylinder head,
the inner-head coolant passage includes a main coolant passage formed in a portion above the combustion chambers, and a pair of upper and lower exhaust side coolant passages that are formed so as to interpose the exhaust collection portion,
at least an upper exhaust side coolant passage of the exhaust side coolant passages is separated from the main coolant passage, is formed so as t

Assignees

• Honda Motor Co Ltd

Inventors

• Ogino Hirotaka
• Takatoku Takayuki
• Konishi Yukio

Classifications

• F01P3/14

  for cooling intake or exhaust valves · CPC title

• F01P7/16

  by thermostatic control · CPC title

• F01P3/02 Primary

  Arrangements for cooling cylinders or cylinder heads · CPC title

• F01P2003/024

  Cooling cylinder heads · CPC title

• F02F1/40

  cylinder heads with means for directing, guiding, or distributing liquid stream · CPC title