JP2000170600A - Cylinder head cooling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling efficiency of a combustion surface by providing at least one pipe allowing two circumferential cooling water passages surrounding the circumferences of two exhaust ports to communicate with each other so as to extend through a port-to-port cooling water passage to a cylinder head. SOLUTION: In the cooling structure for a cylinder head 1, a pipe 90 allowing circumferential cooling water passages 61, 62 to communicate with each other is provided so as to directly extend through the bottom part of an exhaust port-to-exhaust port cooling water passage opposed to an exhaust port-to-exhaust port part 22. One hole opened toward the bottom surface of the exhaust port-to- exhaust port cooling passage is formed in the pipe 90. The cooling water in the circumferential cooling water passages 61, 62 is carried to the pipe 90 and injected toward the bottom surface through the hole. Therefore, the cooling water quantity per unit time making contact with the exhaust port-to-exhaust port part 22 is increased to improve the cooling efficiency of the exhaust port-to- exhaust port part 22 and, in its turn, a hot spot 20. Accordingly, the cooling efficiency of a combustion surface 20 by the cylinder head 1 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head cooling structure capable of improving the cooling efficiency of a combustion surface of a cylinder head.

[0002]

2. Description of the Related Art When a combustion surface of a cylinder head is overheated, problems such as engine stoppage and damage may occur, so that engine reliability cannot be maintained. Therefore, the combustion surface of the cylinder head is cooled by flowing cooling water through a large number of cooling water passages formed inside the cylinder head. On the other hand, the output required of the engine is increasing, and the temperature of the combustion surface is increasing accordingly. Therefore, a new cylinder head cooling structure having high combustion surface cooling efficiency has been demanded.

An object of the present invention is to provide a cylinder head cooling structure that can improve the efficiency of cooling the combustion surface of a cylinder head.

[0004]

Means for Solving the Problems The present inventors have made the following findings while earnestly studying the cooling structure of the cylinder head. That is, the combustion surface does not have a high temperature throughout the entire surface, but has a portion that tends to reach a high temperature and a portion that does not. By intensively cooling the parts that are likely to be high in temperature, the cooling efficiency of the combustion surface can be improved.

FIG. 1 is a view showing a combustion surface of a cylinder head. In the combustion surface 2 of the cylinder head 1 having a structure in which the periphery of the exhaust valve 30 is forcibly cooled by providing the valve seat 301 as shown in FIG. The portion (hereinafter, referred to as a hot spot) 20 is substantially the same as the portion between the two exhaust ports 31 and 32 and the peripheral edge 21 of the combustion surface 2 between the exhaust ports 22 (shown by a dashed line). Corresponds to the center. In addition, 41 and 42 are intake ports.

According to the first aspect of the present invention, a pipe for interconnecting two surrounding cooling water passages respectively surrounding the two exhaust ports is provided between the two exhaust ports on the combustion surface of the cylinder head and the periphery of the combustion surface. One or more cooling water passages in the cylinder head inside the cylinder head facing the portion between the exhaust ports are provided, and one or more holes provided in the pipe are used to connect between the ports facing the portion between the exhaust ports. A cylinder head cooling structure characterized in that cooling water is injected toward a bottom surface of a cooling water passage.

According to a second aspect of the present invention, in the first aspect of the present invention, the pipe is provided so as to penetrate a portion of the inter-port cooling water passage that faces the substantially central portion of the inter-exhaust port portion. Then, the cooling water is injected toward the bottom surface of the inter-port cooling water passage facing the substantially central portion of the portion between the exhaust ports.

According to a third aspect of the present invention, a pipe having one end communicating with at least one of two peripheral cooling water passages respectively surrounding the two exhaust ports is provided by connecting the two exhaust ports of the combustion surface of the cylinder head to the periphery of the combustion surface. One or more ports are provided so that the other end is located in the inter-port cooling water passage inside the cylinder head which faces the inter-exhaust port portion which is a portion between the port and the port facing the inter-exhaust port portion from the other end. A cylinder head cooling structure, characterized in that cooling water is injected toward a bottom surface of a cooling water passage.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the other end of the pipe is positioned in a portion of the inter-port cooling water passage that faces substantially the center of the exhaust port portion. The cooling water is injected from the other end toward a bottom surface of the inter-port cooling water passage that faces the substantially central portion of the portion between the exhaust ports.

According to a fifth aspect of the present invention, at least one of two peripheral cooling water passages respectively surrounding the two exhaust ports is provided with one or more holes so as to inject cooling water toward the outer wall of the exhaust port. This is a cylinder head cooling structure characterized by forming the following.

[0011]

(Embodiment 1) FIG. 2 is a bottom view of a cylinder head according to this embodiment, and FIG. 3 is a longitudinal sectional view showing a state in which an exhaust valve is attached to an exhaust port.
It is a figure corresponding to a III-III cross section. FIG. 4 is a sectional view taken along the line IV-IV
It is sectional drawing. FIG. 4 also includes a partially enlarged view.
The combustion surface 2 of the cylinder head 1 has two exhaust ports 31 and 32 and two intake ports 41 and 42, respectively. A substantially central portion of the inter-exhaust-port portion 22, which is a portion between the exhaust ports 31 and 32 and the peripheral edge 21 of the combustion surface 2, has a hot spot 20 which is likely to have the highest temperature on the combustion surface 2.
It is. On the other hand, a large number of cooling water passages are formed inside the cylinder head 1, and a cooling water passage 51 between the exhaust ports is formed facing the inter-exhaust port portion 22. Further, around the exhaust ports 31 and 32, an exhaust port 3 is provided.
Surrounding cooling water passages 61 and 62 surrounding the cooling water passages 1 and 32 are formed. Peripheral cooling water passages 61, 62 are longitudinal cooling water passages 71, 72, 7 penetrating the cylinder head 1 vertically.
3,74 adjacent cooling water passages 71,72
From each other. As shown in FIG. 3, the exhaust valve 30 is fitted into the exhaust ports 31 and 32 from the combustion surface 2 side, and the surrounding cooling water passages 61 and 6 are provided.
2 is configured by fitting the exhaust valve 30.

In the cylinder head cooling structure of the present embodiment, the pipe 90 for communicating the surrounding cooling water passages 61 and 62 with each other is formed by connecting the bottom of the inter-exhaust-port cooling water passage 51 facing the inter-exhaust-port portion 22 with a straight line. It is provided so as to penetrate. The pipe 90 has an exhaust port intervening portion 22.
One hole 901 that opens toward the bottom surface 511 of the inter-exhaust-port cooling water passage 51 that faces the exhaust port is formed. In addition,
The pipe 90 is made of copper or SUS.

In the above cooling structure, the cooling water in the peripheral cooling water passages 61 and 62 flows into the pipe 90 and
From the bottom port 511, the amount of cooling water per unit time in contact with the exhaust port space 22 increases,
The cooling efficiency of the inter-exhaust-port portion 22 and thus the hot spot 20 is improved. Therefore, the combustion surface 2 of the cylinder head 1
Cooling efficiency is improved.

(Embodiment 2) FIG. 5 is an enlarged partial view of a combustion surface of a cylinder head in this embodiment. In this embodiment, the pipe 90 is provided through the bottom of the cooling water passage 51 between the exhaust ports facing the hot spot 20, and the hole 90 is provided.
01 is opened toward the bottom surface 511 of the cooling water passage 51 between the exhaust ports facing the hot spot 20, and the other configuration is the same as that of the first embodiment. Here, the pipe 9
0 has a curved shape.

In the above-described cooling structure, the amount of cooling water contacting the hot spot 20 per unit time is increased, and the cooling efficiency of the hot spot 20 is improved. Therefore, the cooling efficiency of the combustion surface 2 is further improved as compared with the first embodiment.

(Embodiment 3) FIG. 6 is an enlarged partial cross-sectional view of a cylinder head according to this embodiment, which corresponds to the enlarged view of FIG. In the present embodiment, the pipe 90
Three holes 901 are formed, and the rest is the same as the first embodiment.

In the above-described cooling structure, the amount of cooling water per unit time in contact with the inter-exhaust-port portion 22 is larger than that in the first embodiment. The efficiency is further improved, and thus the cooling efficiency of the combustion surface 2 is further improved.

If the number of holes 901 is plural,
Not limited to three. Further, the cooling structure can be applied to the second embodiment. Even in that case, hot spot 2
The amount of cooling water per unit time that contacts 0
In this case, the cooling efficiency of the hot spot 20 is further improved, so that the cooling efficiency of the combustion surface 2 is further improved.

(Embodiment 4) FIG. 7 is an enlarged partial view of a combustion surface of a cylinder head according to this embodiment. In the present embodiment, two pipes 90 are provided.
Are provided in the same manner as the respective pipes 90 in the first and second embodiments, and are otherwise the same as in the first embodiment.

In the above-described cooling structure, the cooling efficiency of the inter-exhaust-port portion 22 including the hot spot 20 is further improved, so that the cooling efficiency of the combustion surface 2 is further improved.

Incidentally, three or more pipes 90 may be provided. Further, the cooling structure of the third embodiment in which a plurality of holes 901 are formed may be applied to the present embodiment.

(Embodiment 5) FIG. 8 is an enlarged partial cross-sectional view of a cylinder head according to the present embodiment, which corresponds to the enlarged view of FIG. FIG. 9 is a view on arrow IX in FIG. In the present embodiment, a pipe 91 is provided instead of the pipe 90 in the first embodiment, and the other configuration is the same as the first embodiment. One end of the pipe 91 has the peripheral cooling water passage 6.
1 and the other end is provided at the bottom of the inter-exhaust port cooling water passage 51 facing the inter-exhaust port portion 22. The opening 911 at the other end of the pipe 91 faces the bottom surface 511. The pipe 91 is made of copper or SU
Made of S.

In the above cooling structure, since the cooling water in the surrounding cooling water passage 61 is injected from the opening 911 to the bottom surface 511 through the pipe 91, the amount of cooling water per unit time that comes into contact with the exhaust port space 22. And the cooling efficiency of the exhaust port space 22 and thus the hot spot 20 is improved. Therefore, the cooling efficiency of the combustion surface 2 is improved.

The pipe 91 may have one end communicating with the surrounding cooling water passage 62.

(Embodiment 6) FIG. 10 is an enlarged partial view of a combustion surface of a cylinder head in this embodiment. In the present embodiment, the pipe 91 is provided so that the other end is located at the bottom of the cooling water passage 51 between the exhaust ports facing the hot spot 20, and the opening 911 at the other end of the pipe 91 faces the hot spot 20. Cooling water passage 51 between ports
The other configuration is the same as that of the fifth embodiment.

In the above-described cooling structure, the amount of cooling water contacting the hot spot 20 per unit time is increased, and the cooling efficiency of the hot spot 20 is improved. Therefore, the cooling efficiency of the combustion surface 2 is further improved as compared with the fifth embodiment.

Note that one end of the pipe 91 may communicate with the surrounding cooling water passage 62.

(Embodiment 7) FIG. 11 is an enlarged partial view of a combustion surface of a cylinder head in this embodiment. In the present embodiment, two pipes 91 are provided.
Are provided in the same manner as the respective pipes 91 in the fifth and sixth embodiments, and are otherwise the same as in the fifth embodiment. One of the two pipes 91 communicates with the surrounding cooling water passage 61, and the other communicates with the surrounding cooling water passage 62.

In the above-mentioned cooling structure, the cooling efficiency of the inter-exhaust-port portion 22 including the hot spot 20 is further improved, so that the cooling efficiency of the combustion surface 2 is further improved.

Incidentally, three or more pipes 91 may be provided.

(Eighth Embodiment) FIG. 12 is an enlarged partial cross-sectional view of a cylinder head according to this embodiment, which corresponds to the enlarged view of FIG. In this embodiment, since the position of the bottom surface 511 of the cooling water passage 51 between the exhaust ports is high, the pipe 90 is provided in a bridge shape, and the other configuration is the same as that of the first embodiment.

In the above-described cooling structure, as in the first embodiment, the space 22 between the exhaust ports and the hot spot 20
, The cooling efficiency of the combustion surface 2 is improved.

The cooling structure in which the pipe 90 has a bridge shape can be applied to the second to fourth embodiments.

(Embodiment 9) FIG. 13 is an enlarged partial cross-sectional view of a cylinder head according to this embodiment, and corresponds to the enlarged view of FIG. In this embodiment, since the position of the bottom surface 511 of the cooling water passage 51 between the exhaust ports is high, the pipe 91 is provided to extend diagonally upward, and the other components are the same as those of the fifth embodiment.

Also in the above cooling structure, similarly to the fifth embodiment, the inter-exhaust-port portion 22 and thus the hot spot 20 are formed.
, The cooling efficiency of the combustion surface 2 is improved.

The cooling structure in which the pipe 91 extends obliquely upward is also applicable to the sixth and seventh embodiments.

(Embodiment 10) FIG. 14 is a partial longitudinal sectional view of a cylinder head according to this embodiment. Two exhaust ports 31 and 32 are open in the combustion surface 2 of the cylinder head 1. On the other hand, a large number of cooling water passages are formed inside the cylinder head 1, and both exhaust ports 31,
A cooling water passage 51 between the exhaust ports facing the inter-exhaust-port portion 22 is formed between the exhaust ports 32. Further, peripheral cooling water passages 61 and 62 surrounding the exhaust ports 31 and 32 are formed around the exhaust ports 31 and 32, respectively. The peripheral cooling water passages 61 and 62 extend from longitudinally extending cooling water passages penetrating the cylinder head 1 vertically.

In the cylinder head cooling structure of this embodiment, the outer wall 321 of the exhaust port 32 on the exhaust port 31 side is provided on the portion of the peripheral cooling water passage 61 on the exhaust port 32 side.
A hole 612 is formed so as to inject the cooling water as shown by arrow A toward the outer wall 321 of the exhaust port 32 in a portion of the surrounding cooling water passage 62 opposite to the exhaust port 31. The hole 622 is formed so as to inject cooling water toward the outer wall 322 on the opposite side as shown by arrow B.

In the above cooling structure, the cooling water in the surrounding cooling water passage 61 is injected into the inter-exhaust port cooling water passage 51 and blown to the outer wall 321, and the cooling water in the surrounding cooling water passage 62 is cooled in the inter-exhaust port cooling water. Since the fuel is injected into the passage 52 and blown to the outer wall 322, the amount of cooling water per unit time that contacts the outer walls 321 and 322 increases. Therefore, the cooling efficiency of the exhaust port 32 is improved, and the cooling efficiency of the entire cylinder head 1 is improved.

In FIG. 14, a portion of the surrounding cooling water passage 62 on the exhaust port 31 side is
A hole 623 is formed to inject cooling water toward the outer wall 311 of the exhaust port 31 on the exhaust port 32 side as shown by an arrow C.
May be formed. According to this, the cooling efficiency of the exhaust port 31 is improved. The number of holes 612, 622, and 623 may be plural.

[0041]

According to the first aspect of the present invention, the cooling water in the surrounding cooling water passage can be injected from the hole of the pipe toward the bottom surface of the inter-port cooling water passage. Thus, the cooling water amount per unit time can be increased, the cooling efficiency between the exhaust ports and the hot spot can be improved, and therefore the cooling efficiency of the combustion surface of the cylinder head can be improved.

According to the second aspect of the present invention, the amount of cooling water per unit time contacting the hot spot can be increased,
The cooling efficiency of the hot spot can be improved, and therefore, the cooling efficiency of the combustion surface can be further improved.

According to the third aspect of the present invention, since the cooling water in the peripheral cooling water passage can be injected from the other end of the pipe toward the bottom surface of the inter-port cooling water passage, the cooling water comes into contact with the portion between the exhaust ports. The amount of cooling water per unit time can be increased, and the cooling efficiency between the exhaust ports and thus the hot spot can be improved. Therefore, the cooling efficiency of the combustion surface of the cylinder head can be improved.

According to the fourth aspect of the present invention, the amount of cooling water per unit time contacting the hot spot can be increased,
The cooling efficiency of the hot spot can be improved, and therefore, the cooling efficiency of the combustion surface can be further improved.

According to the fifth aspect of the present invention, since the cooling water in the surrounding cooling water passage can be injected toward the outer wall of the exhaust port, the amount of cooling water contacting the outer wall per unit time can be increased. The cooling efficiency of the exhaust port can be improved, and the cooling efficiency of the entire cylinder head can be improved.

[Brief description of the drawings]

FIG. 1 is a view showing a combustion surface of a cylinder head.

FIG. 2 is a bottom view of the cylinder head according to the first embodiment.

FIG. 3 is a longitudinal sectional view showing a state where an exhaust valve is attached to an exhaust port, and is a view corresponding to a section taken along line III-III of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is an enlarged partial view of a combustion surface of a cylinder head according to a second embodiment.

FIG. 6 is an enlarged partial longitudinal sectional view of a cylinder head according to a third embodiment.

FIG. 7 is an enlarged partial view of a combustion surface of a cylinder head according to a fourth embodiment.

FIG. 8 is an enlarged partial cross-sectional view of a cylinder head according to a fifth embodiment.

9 is a view as viewed in the direction of the arrow IX in FIG. 8;

FIG. 10 is an enlarged partial view of a combustion surface of a cylinder head according to a sixth embodiment.

FIG. 11 is an enlarged partial view of a combustion surface of a cylinder head according to a seventh embodiment.

FIG. 12 is an enlarged vertical cross-sectional view of a cylinder head according to an eighth embodiment.

FIG. 13 is an enlarged partial cross-sectional view of a cylinder head according to a ninth embodiment.

FIG. 14 is a partial vertical cross-sectional view of a cylinder head according to a tenth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Combustion surface 20 Hot spot 21 Peripheral edge (of combustion surface) 22 Exhaust port portion 31, 32 Exhaust port 311, 321, 322 Outer wall 51 Exhaust port cooling water passage 511 Bottom surface 61, 62 Surrounding cooling water passage 901 hole 911 opening

Claims (5)

[Claims] An exhaust port, which is a portion between two exhaust ports on a combustion surface of a cylinder head and a peripheral edge of the combustion surface, connects a pipe for interconnecting two peripheral cooling water passages respectively surrounding the two exhaust ports. One or more ports are provided through the inter-port cooling water passage inside the cylinder head facing the inter-portion, and the at least one port provided in the pipe is used to form a hole in the bottom of the inter-port cooling water passage facing the inter-exhaust port. A cylinder head cooling structure characterized by injecting cooling water toward the cylinder head. 2. A pipe is provided so as to penetrate a portion of the inter-port cooling water passage which faces a substantially central portion of the inter-exhaust port portion,
2. The cylinder head cooling structure according to claim 1, wherein the cooling water is injected from a hole of the pipe toward a bottom surface of the cooling water passage between the ports facing a substantially central portion between the exhaust ports. 3. A pipe having one end communicating with at least one of two surrounding cooling water passages respectively surrounding the two exhaust ports at a portion between both exhaust ports on the combustion surface of the cylinder head and the periphery of the combustion surface. One or more other ends are provided in the inter-port cooling water passage inside the cylinder head facing a certain exhaust port portion, and the bottom surface of the inter-port cooling water passage facing the exhaust port portion from the other end. A cooling structure for injecting cooling water toward the cylinder head. 4. A pipe is provided such that the other end is located in a portion of the interport cooling water passage facing the substantially central portion of the exhaust port portion, and from the other end, the pipe of the interport cooling water passage is provided. 4. The cylinder head cooling structure according to claim 3, wherein cooling water is injected toward a bottom surface facing a substantially central portion of the exhaust port space. 5. A method according to claim 1, wherein one or more holes are formed in at least one of two peripheral cooling water passages respectively surrounding the two exhaust ports so as to inject cooling water toward an outer wall of the exhaust port. Cylinder head cooling structure.