JPH0526108A - Cylinder head cooling system for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] The circulation of cooling water between the exhaust ports is promoted to eliminate the stagnation of the cooling water between the exhaust ports and improve the cooling efficiency of the exhaust port to improve thermal fatigue and thermal strain. And a cylinder head cooling device for an internal combustion engine that can prevent the occurrence of cracks. [Structure] The lower side of the exhaust ports 31, 32 in the cylinder arrangement direction is blocked by a partition wall 16 so that cooling water cannot flow, and the exhaust ports 31, 3 adjacent to the partition wall 16 are provided.
Exhaust port lower cooling water inlets 13 and 13 are formed substantially below 2 and cooling water supplied from the exhaust port lower cooling water inlets 13 and 13 flows between the exhaust ports 31 and 32 to the intake port side. The cooling water passage 15 between the exhaust ports is formed.

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 device for an internal combustion engine having two exhaust ports for one cylinder, and more particularly to a cooling water passage structure thereof.

[0002]

2. Description of the Related Art In a reciprocating engine, which is a typical internal combustion engine, a cylinder head having a combustion chamber and intake / exhaust ports each having an on-off valve is formed above a cylinder block. Cooling of the head is performed by supplying cooling water from the water jacket of the cylinder block through the joint surface and discharging the water around the cylinder head. Recently, it has been attempted to increase intake / exhaust efficiency by increasing the intake / exhaust efficiency by increasing the number of intake / exhaust ports (intake / exhaust valves) (multi-valve). It is necessary to set in consideration of the cooling of the exhaust port portion which becomes high temperature.
As disclosed in Japanese Laid-Open Patent Publication No. 1388862, in a device provided with two exhaust ports for a position cylinder, cooling water inlets from the cylinder block side are respectively arranged below the two exhaust ports, and two exhaust ports are provided. A cooling water passage is proposed between the ports.

[0003]

However, in the conventional structure as described above, the cooling water introduced from the cooling water introduction port from the cylinder block side arranged below the two exhaust ports is
There is a problem that the cooling water does not flow to the side of the cooling water passage between the narrow exhaust ports but flows to the adjacent cylinder side, and the cooling water stagnates in the cooling water passage portion between the exhaust ports, so that the exhaust port is not cooled well. As a result, the temperature of the exhaust port becomes high,
As a result, there is a risk that cracks may occur due to thermal fatigue of the high temperature portion and thermal strain caused by the temperature difference.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention promotes the flow of cooling water between exhaust ports to eliminate the stagnation of the cooling water between the exhaust ports and improve the cooling efficiency of the exhaust port portion. An object of the present invention is to provide a cylinder head cooling device for an internal combustion engine that can eliminate thermal fatigue and thermal strain and prevent the occurrence of cracks.

[0005]

Therefore, in the cylinder head cooling apparatus for an internal combustion engine according to the present invention, the cooling water is blocked by the partition walls so that the lower side of both exhaust ports in the cylinder arrangement direction is adjacent to the partition walls. A cooling water inlet is formed substantially below each exhaust port, and a cooling water passage is formed between both exhaust ports, through which the cooling water introduced from the cooling water inlet flows to the intake port side. . According to this configuration, the cooling water introduced from the cooling water inlet does not flow to the adjacent cylinder side due to being blocked by the partition wall, but flows to the intake port side through the cooling water passage between the exhaust ports, and the exhaust port The stagnation of cooling water in the vicinity is eliminated, and the exhaust port is cooled well.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a cylinder head of one bank of a V-type 6-cylinder engine to which an embodiment of a cylinder head cooling device for an internal combustion engine according to the present invention is applied, in which the sectional division positions are changed horizontally in the thickness direction. FIG. 3 is a divided sectional view, and FIG. 3 is a partial sectional view of an exhaust port portion thereof. In the illustrated cylinder head 10, combustion chambers 11 of three cylinders are arranged in series, and each combustion chamber 11 has three intake ports 20 (21, 22, 23) and two exhaust ports. 30 (31, 32) are provided and configured as a so-called 5 valve. In FIG. 1, the right side of the center of the cylinder is the boundary: R is a cross section at a horizontal position toward the upper side, and the left side:
L is shown as a cross section at a horizontal position near the lower surface (cylinder block), and FIG. 2 shows the left side of FIG. 1: the left end cylinder in FIG. 1 at a horizontal position closer to the lower surface (cylinder block) than L. It is the figure which made the part the cross section.

The cylinder head 10 includes an intake port 20,
The cooling water passage 12 is hollow except that the exhaust port 30 and the spark plug mounting portion 40 have a predetermined thickness. Cooling water is supplied to the cooling water passage 12 from a water jacket of a cylinder block (not shown) through a cooling water introducing port 13 ... , The cooling water circulates through the cooling water passage 12 and the intake port 20.
It is configured to be discharged from a discharge port 14 formed at an end portion in the longitudinal direction on the side. Intake ports 21, 22, 23
The exhaust ports 31 and 32 are arranged in a substantially annular opening along the outer periphery of the combustion chamber 11, and in the center of the combustion chamber 11, a cylindrical spark plug mounting portion 40 is provided. Between the exhaust ports, the outer wall of the spark plug mounting portion 40 is formed so as to be separated from the outer walls of the intake port 20 and the exhaust port 30. The cooling water can flow through the separating portion.

Intake ports 21, 2 opening in the same cylinder
2 and 23 are formed independently from the opening on the side of the combustion chamber 11 halfway, and are merged and integrated to open on the upper side surface in the figure, but the port outer wall 20A is formed continuously and integrally. . Also, the exhaust ports 31, 32 opening to the same cylinder
Are formed in a tubular shape independently from the opening on the side of the combustion chamber 11 partway, and are merged and integrated halfway to open on the side wall on the lower side in the drawing. An exhaust port-to-exhaust port cooling water passage 15 that communicates in the up-down direction (thickness direction of the cylinder head 10) is formed between the port outer walls of independent portions of the exhaust ports 31 and 32, unlike the intake port 20 side.

The cooling water passage 15 between the exhaust ports 31 and 32 is a longitudinal sectional view (corresponding to the section AA of FIG. 2) orthogonal to the exhaust ports 31 and 32 at the relevant portion.
As shown in FIG. 3, a partition wall 16 that connects the upper and lower sides is formed at the outer (adjacent cylinder side) ends of both exhaust ports 31, 32, and the exhaust ports 31, 32 adjacent to this partition wall 16 are formed.
On the lower side, the exhaust port lower cooling water introduction ports 13 to which the cooling water is supplied from the cylinder block side are formed respectively. The supply of the cooling water from the cylinder block side is not limited to the exhaust port lower cooling water inlet 13 ...
It is also designed to be performed from a plurality of cooling water inlets 17 ... Which are respectively arranged on the lower side of 22, 23 and on both sides between the cylinders. In the figure, 51 is a head bolt hole for fastening the cylinder head 10 to the cylinder block, 52 is an oil return passage for returning lubricating oil to the cylinder block side, and 53 is a valve guide hole.

In the cylinder head 10 constructed as described above, the cooling water inlet port 1 is introduced from the cylinder block side.
Cooling water is supplied into the cooling water passage 12 via 3 ..., 17 ..., The supplied cooling water circulates in the cooling water passage 12 to pass through the exhaust port 30, the spark plug mounting portion 40 and the intake port 20. It is cooled and discharged from the discharge port 14. here,
The cooling water supplied from the exhaust port lower cooling water inlet 13 disposed below the exhaust ports 31 and 32 contacts the lower wall surface of the exhaust ports 31 and 32, and the outflow to the adjacent cylinder side is achieved by the partition wall 16. The cooling water introduction port 13 below the exhaust port is opened adjacent to the partition wall 16 between the exhaust ports 31 and 32 without stagnation in the lower part of the exhaust ports 31 and 32. It flows out to the upper side through the formed cooling water passage 15 between the exhaust ports, hits the outer wall of the spark plug mounting portion 40, cools it, and cools the intake port 20.
To the side. That is, the exhaust port 30 (3
1, 32), and then the spark plug mounting part 40 is cooled to flow to the intake port 20 side, whereby the exhaust ports 31, 32, which have the highest temperature, are efficiently cooled to prevent the temperature from rising. It is possible to cool the spark plug mounting portion 40 that causes premature ignition due to high temperature.

[0011]

As described above, according to the cylinder head cooling device for an internal combustion engine of the present invention, the flow of the cooling water supplied from the lower side of the exhaust port to the adjacent cylinder side is blocked by the partition wall, and the exhaust port is prevented. Since it reaches the intake side through the intercooling water passage, the stagnation of the cooling water between the exhaust ports is eliminated and the circulation of cooling water between the exhaust ports is promoted.
It is possible to efficiently cool the exhaust port portion, prevent the exhaust port from rising in temperature, eliminate thermal fatigue and thermal strain, and prevent cracks from occurring.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in which a cylinder head of one bank of a V-type 6-cylinder engine to which an embodiment of a cylinder head cooling device for an internal combustion engine according to the present invention is applied is horizontally divided by changing the cross-section dividing position in the thickness direction. Fig.

FIG. 2 is a cross-sectional view horizontally divided at a horizontal position closer to the lower surface than in FIG.

3 is a partial cross-sectional view orthogonal to an exhaust port corresponding to the AA cross section of FIG.

[Explanation of symbols]

10 ... Cylinder head 13 ... Cooling water inlet under the exhaust port (cooling water inlet) 15 ... Cooling water passage between exhaust ports 16 ... Partition 20 (21, 22, 23) ... Intake port 30 (31, 32) ... Exhaust port 40 ... Spark plug mounting part

Claims (2)

[Claims] 1. A cylinder head of an internal combustion engine having two exhaust ports for one cylinder, the cooling water path of which is such that cooling water introduced from the exhaust port side is discharged from the intake port side. In the configuration, the lower side of the exhaust port in the cylinder arrangement direction is blocked by a partition wall so that cooling water cannot flow, and the cooling water is introduced substantially below the respective exhaust ports adjacent to the partition wall. And an exhaust port cooling water passage is formed between the exhaust ports, through which the cooling water supplied from the cooling water inlet flows to the intake port side. Engine cylinder head cooling system. 2. A position having three intake ports for one cylinder, the position interfering with a cooling water flow flowing to the intake port through the cooling water passage between the exhaust ports formed between the exhaust ports. The cylinder head cooling device for an internal combustion engine according to claim 1, wherein an ignition plug mounting portion is arranged in the.