JPH0140215B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cooling structure for a cross-flow internal combustion engine.

BACKGROUND OF THE INVENTION A cylinder head of an internal combustion engine is provided with a water jacket, through which cooling water flows to cool the cylinder head. In the case of a compact cylinder head, sufficient water jacket space between the valves cannot be secured, making it difficult to cool the valves and valve seats properly, which can cause uneven wear and seizure, so careful consideration must be given to the cooling structure. must be done. In some diesel engines, which are particularly subjected to thermal conditions, a passage is provided that runs from the outer wall of the cylinder head to the water jacket and penetrates between the valves in order to compensate for the lack of cooling water passages. It cannot be said that the effect is sufficient.

A typical example of an internal combustion engine having this type of cooling water passage structure is shown in Japanese Utility Model Application Laid-open No. 54-72239. The main points of the conventional structure will be explained using FIG. 5 as follows.

(a) A water passage 3 is provided which runs diagonally downward from the in-block water jacket 2 on one side to the in-block water jacket 1 on the other side.

(b) A water hole 4 having a sudden cross-sectional change part 4a is provided on the lower surface of the cylinder head on one side, and a water passage 7 that passes diagonally upward into the water jacket 6 in the head on the other side of the water hole 4 is provided. is provided.

Problems to be Solved by the Invention However, in such a cooling structure, when cooling an internal combustion engine, a large amount of water is generally flowed into the water jacket on the side where the exhaust passage is provided, so the water jacket on the other side is Sufficient amount of cooling water cannot be secured in the jacket, and water passage 3 or water passage 7
The cylinder block or cylinder head may not be sufficiently cooled due to the insufficient amount of cooling water passing through the water hole 4. Also, if the water hole 4 has a sudden cross-sectional change part 4a, air bubbles may be generated due to the rapid constriction. However, there was a problem in that water containing air bubbles entered the water passage 3 and the cooling effect was reduced.

In order to solve such problems, the present invention has the following features:
An object of the present invention is to provide a cooling water passage structure that can ensure a sufficient flow of cooling water between valves and between cylinders in a cross-flow type internal combustion engine.

Means for Solving the Problems In order to achieve this object, in the cooling structure for an internal combustion engine of the present invention, in a cross-flow type internal combustion engine, there is a A water hole is provided above the taper portion that gradually decreases in diameter toward the water jacket in the head, and an intake passage is provided through the taper portion of the water hole and between the exhaust valves. A water passage is provided in the water jacket in the head on the side where the cylinder block is located, and an intake passage is provided from the water jacket in the block corresponding to the side where the exhaust passage is provided in the cylinder block. A water passage extending diagonally upward is provided in the water jacket in the block corresponding to the side facing the block.

Function In the cooling structure for an internal combustion engine configured as described above, the water passages provided between the valves of the cylinder head and the water passages provided between the cylinders of the cylinder block are provided on the side where the exhaust passage is provided. Cooling water enters from the water jacket on the side where the intake passage is installed and flows out to the water jacket on the side where the intake passage is installed, so a sufficient amount of cooling water flows from the water jacket on the side where the exhaust passage is installed. can be introduced into the water passage, allowing sufficient cooling between valves and cylinders. In addition, since water is taken in from the tapered part of the water hole in the head internal water passage, compared to the conventional case where water is taken in from the part where the flow is suddenly constricted, there is less generation of bubbles and cooling. It will not cause any hindrance.

Embodiments Hereinafter, preferred embodiments of the cooling structure for an internal combustion engine of the present invention will be described with reference to the drawings.

1 to 4 show embodiments of the present invention. In the figure, 11 is a cylinder block of an internal combustion engine;
12 is a cylinder head, cylinder head 1
2 is provided with an intake passage 13 on one side of the engine and an exhaust passage 14 on the other side, so that the gas flow has a cross-flow structure.

In order to cool the cylinder head, the cylinder head 12 is provided with an in-head water jacket 15 on the side where the intake passage 13 is provided and an in-head water jacket 16 on the side where the exhaust passage 14 is provided. The water jackets 15 and 16 are in communication with each other. An in-block water jacket 17 extending in the longitudinal direction of the engine is provided in a portion of the cylinder block 11 corresponding to the side where the intake passage 13 is provided, and is connected to the exhaust passage 14.
an in-block water jacket 18 extending longitudinally of the engine in a portion corresponding to the side where the engine is provided;
is provided. Cooling water from the water pump 26 is introduced into both in-block water jackets 17 and 18, but the intake passage 13 is introduced into the in-block water jacket 18 corresponding to the side where the exhaust passage 14 is provided. A larger amount of cooling water flows through the in-block water jacket 17 corresponding to the side where the block is provided.

Water holes 19, 20 are provided on the lower surface of the cylinder head to introduce water from the in-block water jackets 17, 18 to the in-head water jackets 15, 16. Exhaust passage 1 among water holes 19 and 20
A water hole 20 that guides water from the in-block water jacket 18 on the side where the exhaust passage 14 is provided to the water jacket 16 on the side where the exhaust passage 14 is provided.
The cylinder head has a tapered portion 21 whose diameter gradually decreases upward from the lower surface of the cylinder head.

An intake passage 13 is provided in the tapered portion 21 of the water hole 20, extending from the in-head water jacket 16 on the side where the exhaust passage 14 is provided, and passing through the cylinder head wall between the valves of the exhaust valve. A water passage 22 is provided which extends obliquely upward to the side in-head water jacket 15.

Also, the cylinder side wall surface 18 of the in-block water jacket 18 on the side where the exhaust passage 14 is provided.
A slope portion 23 is formed in the wall surface 18b on the opposite side and gradually approaches the wall surface 18b as it goes upward.
The inclined portion 23 has an in-block water jacket 18 corresponding to the side where the exhaust passage 14 is provided.
A water passage 24 extends obliquely upward through the block wall between the cylinders toward the in-block water jacket 17 corresponding to the side where the intake passage is provided.
is provided.

A gasket 25 is interposed between the cylinder head 12 and the cylinder block 11, and the gasket 25 is provided with holes at positions corresponding to the water holes 19 and 20 to allow water to flow therethrough. The hole on the water hole 19 side is formed smaller than the hole on the water hole 20 side.

In the apparatus configured as described above, the engine is cooled as follows.

First, cooling water is sent by the water pump 26 to the water jackets 17 and 18 in the block.
Flow inside. Water jacket in block 1
At 7 and 18, a large amount of water flows toward the in-block water jacket 18 corresponding to the side where the exhaust passage 14 is provided. The cooling water rises upward while cooling the cylinder block 11. Some of the cooling water passes through the water passages 24 in the inclined portions 23 within the block to effectively cool the block walls between the cylinders. This water flows into the in-block water jacket 17 corresponding to the side where the intake passage 13 is provided. Since the cooling water is taken into the water passage 24 through the inclined portion 23, water can be easily taken in, and since the water is taken in from a place where the flow is not suddenly constricted, no air bubbles are generated.

The cooling water in the water jackets 17 and 18 in the block is fed to the water holes 19 and 20 in the cylinder head 12.
through the head water jackets 15, 16
The water flows into the cylinder head 12, cools the cylinder head 12, exits the cylinder head 12 and reaches a radiator (not shown), where it is cooled and circulated to the water pump 26.

In the cylinder head 12, part of the cooling water passes through the water passage 21 from the tapered part 21 of the water hole 20,
To effectively cool the head wall between exhaust valves. Cooling water is introduced into the water passage 21 through the taper section 2.
1, it is easy to take in a large amount of water, and since the water is not taken in from a part where the flow is suddenly constricted, the generation of air bubbles is suppressed and does not interfere with cooling.

Effects of the Invention Therefore, when using the internal combustion engine cooling structure of the present invention, a large amount of cooling water can pass through the water passages between the valves and between the cylinders, and the parts that are most difficult to cool can be cooled well. Since air bubbles in the water passed through the water passage are also suppressed, cooling is not hindered.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an internal combustion engine to which the cooling structure of the present invention is applied, Fig. 2 is a sectional view of the cylinder head of the internal combustion engine shown in Fig. 1, viewed from a direction perpendicular to Fig. 1, and Fig. 3. is a plan view of the cylinder block portion of the internal combustion engine shown in FIG. 1, FIG. 4 is a plan view of the cylinder head portion of the internal combustion engine shown in FIG. 1, and FIG. 5 is a sectional view of the internal combustion engine with a conventional cooling structure. . 11... Cylinder block, 12... Cylinder head, 13... Intake passage, 14... Exhaust passage,
15... Water jacket in the head (intake passage side), 16... Water jacket in the head (exhaust passage side, 17... Water jacket in the block (intake passage side), 18... Water jacket in the block (exhaust passage side) aisle side), 19... water hole, 20...
...Water hole, 21...Tapered part, 22...Water passage, 2
3... Inclined portion, 24... Water passage, 25... Gasket, 26... Water pump.

Claims (1)

[Claims] 1 In a cross-flow type internal combustion engine, the lower surface of the cylinder head on the side where the exhaust passage is provided has a taper portion whose radius gradually decreases upward, and a water hole that drains into the water jacket in the head above the taper portion. A water passage is provided that passes through the taper part of the water hole and passes between the exhaust valves and exits diagonally upward into the water jacket in the head on the side where the intake passage is provided, and an exhaust passage is also provided in the cylinder block. An internal combustion engine characterized in that a water passage is provided diagonally upwardly from the water jacket in the block corresponding to the side where the intake passage is provided to the water jacket in the block corresponding to the side where the intake passage is provided. Cooling structure.