JP3170086B2 - Internal combustion engine cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an internal combustion engine in which cooling water is supplied to a water jacket in a cylinder head. The position of the water pump and the water passage that can secure the cooling water amount,
It relates to improvement of shape and the like.

[0002]

2. Description of the Related Art Conventionally, as a cooling device for supplying cooling water to a water jacket of a cylinder head, for example, as disclosed in Japanese Patent Application Laid-Open No. Sho 61-175217, a water pump is arranged on a cylinder block side. There is a pump in which a pump and a water jacket of a cylinder head are connected by a joint hose made of different parts.

[0003]

However, in the above-mentioned conventional cooling device, a joint hose as a separate part is required, so that there is a problem that the number of parts and the number of assembling steps increase accordingly.

Therefore, it is conceivable to dispose a water pump directly on the cylinder head side in order to eliminate the joint hose. However, in this case, if the highest position in the water pump is higher than the highest position in the water jacket in the cylinder head, air in the pump does not escape during maintenance such as replacement of cooling water, and a malfunction in the function of the pump. May occur. To avoid this problem, make sure that the highest position in the water pump is lower than the highest position in the water jacket,
A small water pump must be used. However, when a small water pump is employed, there is a case where sufficient cooling capacity cannot be obtained due to a shortage of cooling water.

The present invention has been made in view of the above-mentioned conventional problems, and provides a cooling device for an internal combustion engine that can secure a sufficient amount of cooling water without requiring a separate component such as a joint hose. It is intended to be.

[0006]

SUMMARY OF THE INVENTION Accordingly, in the present invention, a water pump is provided in a cylinder head, and a water passage is formed in the cylinder head for communicating a substantially highest position in the volume chamber of the water pump with a water jacket of the cylinder head. Positioning at least a part of the water passage higher than the substantially highest position, providing an air reservoir at a position higher than a connection portion of the water passage to the pump discharge port and the water jacket, and further externally connecting the air reservoir to the outside. A cooling device for an internal combustion engine, characterized in that an air vent hole communicating with the cooling device is provided.

[0007]

According to the cooling device of the present invention, the water pump is disposed directly on the cylinder head and the water pump and the water jacket are communicated with each other through the water passage formed in the cylinder head. No joint hose is required, so that the number of parts and the number of assembling steps can be reduced accordingly.

Further, since a part of the water passage is located at a position higher than a substantially highest position in the water pump and the inside of the water pump is communicated with the higher position, the substantially highest value in the water pump is equal to that of the water jacket. Even when a large water pump that is higher than the highest position is used, air does not accumulate in the pump. Therefore, the large pump can be used, and a sufficient amount of cooling water can be secured.
In addition, an air reservoir is provided at a position higher than a connection portion of the water passage to the pump discharge port and the water jacket,
Further, since an air vent hole for communicating the air reservoir with the outside is provided, the air mixed in the cooling water from the water pump accumulates in the air reservoir and is reliably discharged to the outside from the air vent hole.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 3 are views for explaining an engine cooling apparatus according to an embodiment of the present invention. FIG. 1 is a front view of the engine of the embodiment, FIG. 2 is a front view of a pump portion, and FIG. FIG. 3 is a sectional view taken along line III-III of FIG.

In FIG. 1, reference numeral 1 denotes an engine employing the cooling device of the present embodiment, which is a cylinder block 2 having an oil pan 3 mounted on a lower mating surface and a cylinder block 2 laminated on an upper mating surface of the block 2. The cylinder head 4 includes a fastened cylinder head 4 and a head cover 5 covered on the cylinder head 4.

Reference numeral 6 denotes a crank pulley mounted on an outwardly projecting end of a crankshaft. The pulley 6 is a cam pulley mounted on an outwardly projecting end of a camshaft via a toothed belt 7 meshed with the pulley. 8 and a pump pulley 10 attached to an outer end of a water pump 9 described later. An idler pulley 11 regulates the direction of the belt 7,
Reference numeral 12 denotes a tensioner pulley for absorbing the slack of the belt 7.

The water pump 9 includes a pump base 13 recessed on the outer wall surface of the cylinder head 4 and a pump cover 15 detachably mounted on the pump base 13 with bolts 14.
A pump shaft 17 supported by the pump cover 15 via a bearing 16, an impeller 18 fixed to an inner end of the pump shaft 17, and an impeller 18 fixed to an outer end of the pump shaft 17. And a pump pulley 10.

As shown in FIG. 2, the pump base 13 is formed by forming a flange 13b on the periphery of a circular concave portion 13a constituting a pump volume chamber. A suction passage 4a is provided on the back side (left side in FIG. 3) of the pump base 13.
Are formed. The downstream end of the suction passage 4a is open to the impeller axis portion of the pump base 13, and the upstream end is open to the front wall 4b of the cylinder head. A water inlet 19 is connected to the opening.

A water passage 20 for communicating between a discharge port 13c formed in the pump base 13 and thus at a substantially highest position in the volume chamber of the water pump 9 and a water jacket 21 in the cylinder head 4 is provided in the cylinder head. 4 is formed by integral casting. The water passage 20 is formed so as to extend to a higher position than a line connecting the discharge port 13c and the water jacket 21, and an air reservoir is formed near the upper portion of the discharge port 13c so as to expand further upward. 20a are formed. In addition,
In the water jacket 21, only a portion connected to the water passage 20 is shown. Reference numeral 13d denotes a discharge port to the water jacket in the cylinder head formed near the lower end of the pump base 13.

Further, the cylinder head 4 includes:
An air vent hole 20b extending from the air reservoir 20a toward the cylinder head rear wall 4c is formed.
The outer opening 22d of Ob is connected to a degas bottle 22b via an air vent valve 22a. This degas bottle 2
2b is connected to the closed radiator 22c. The air vent valve 22a opens and closes the passage and removes the air to the outside to discharge the air in the air reservoir 20a to the outside.

Next, the operation and effect of this embodiment will be described. According to the cooling device of the present embodiment, the cooling water is sucked into the water pump 9 from the water return hose 19, where it is pressurized and discharged from the discharge ports 13c and 13d. The cooling water discharged from the discharge port 13c is supplied to the water jacket 21 in the cylinder head 4 through the water passage 20. In this case, since the water in the cooling water is at the highest position, the air in the cooling water accumulates in the top wall of the passage. Therefore, air can be vented by opening the vent valve 22 as needed.

Therefore, for maintenance such as replacement of the cooling water, the air vent valve 22 may be opened to supply the cooling water. Then, the air inside the pump and inside each passage is pushed up into the water passage 20 and accumulates in that portion, and is discharged from the air reservoir 20a to the outside through the air vent hole 20b.

As described above, according to this embodiment, the water pump 9 is directly attached to the cylinder head 4 and
Since the discharge port 13c and the water jacket 21 in the cylinder head 4 are communicated with each other through the water passage 20 formed in the cylinder head 4, a joint hose as a separate part is unnecessary, and the number of parts and the number of assembling steps are reduced accordingly. it can.

The water passage 20 is connected to the discharge port 1
Since the air reservoir 20a which expands above the 3c and the water jacket 21 and further expands upward is provided, and the air reservoir 20a is communicated with the outside through the air vent hole 20b, the air can be reliably vented. As a result, a large water pump whose internal highest value is higher than the maximum position of the water jacket 21 can be adopted as the water pump, and a sufficient amount of cooling water can be secured.

In the above embodiment, the water passage 20
Is connected to the outside through the air vent hole 20b, but the air vent hole 20b is not always necessary. If the air vent hole 20b is not provided, air will accumulate in the water passage. However, there is no practical problem as long as air does not accumulate in the water pump 9.

[0021]

As described above, according to the cooling device for an internal combustion engine according to the present invention, since the water pump is provided directly on the cylinder head, a joint hose or the like as a separate part is not required, and the number of parts and the number of assembly steps are reduced. There is an effect that can be reduced.

Further, a portion located at a position higher than the substantially highest position in the water pump volume chamber is provided in a water passage connecting the water pump and the water jacket, and the water pump is communicated with the portion, so that air accumulates in the pump. It is possible to use a large water pump whose highest value is located higher than the highest position of the water jacket, and a sufficient amount of cooling water can be secured.
This has the effect of improving the cooling capacity. Further, an air reservoir is provided at a position higher than the connection portion between the water passage and the pump discharge port and the water jacket, and an air vent hole for communicating the air reservoir with the outside is provided. This has the effect of reliably discharging the air flowing out of the air reservoir to the outside through the air vent hole.

[Brief description of the drawings]

FIG. 1 is a front view of an engine including a cooling device according to an embodiment of the present invention.

FIG. 2 is a front view of a water pump portion of the engine of the embodiment.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 9 Water pump 4 Cylinder head 21 Water jacket 20 Water passage

Claims (1)

(57) [Claims] 1. A provided a water pump to the cylinder head, the water passage communicating with the water jacket of the substantially highest position and the cylinder head in the volume chamber of the water pump is formed in the cylinder head, at least a portion of the water passage Is positioned higher than the approximately highest position , and
To the pump outlet and water jacket in the water passage
An air reservoir is provided at a position higher than the connection part of
A cooling device for an internal combustion engine, comprising an air vent hole for communicating a reservoir to the outside .