JPH0932633A - Cooling water passage of water cooled horizontal opposed type multi-cylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling performance of a cylinder by disposing a rib, by which the water injection efficiency of cooling water can be improved, and the stay of air can be prevented, and which is excellent in castability, in a water jacket of a cylinder head. SOLUTION: In a water cooled horizontal opposed multi-cylinder engine, ribs 31, 32, 33 are disposed for dividing the inside of a water jacket 10 of a cylinder head 4 into a lower water jacket and an upper water jacket substantially in the center of cylinders 21, 22. Air-bleeding passages 35a, 35b, 35c, 35d are formed on parts where air is easy to stay in the respective ribs 31, 32, 33, and flow ports 34a, 34b, 34c, 34d with small sectional areas where cooling water flows from the lower water jacket to the upper water jacket at a high flow speed along the combustion chamber walls 21a, 22a of the cylinders 21, 22 and the plug hole walls 23a, 24a are formed therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water passage for a water-cooled horizontally opposed multi-cylinder engine that allows cooling water to flow from a water jacket below a cylinder block to a water jacket above a cylinder block via a water jacket of a cylinder head. .

[0002]

2. Description of the Related Art Generally, in a water-cooled in-line engine, cooling water flows in the water jacket of a cylinder block from the front of the engine to the rear, and from the rear of the engine in the water jacket of the cylinder head to the front of the engine. Therefore, the total flow rate of the cooling water passes through the wall surface of each combustion chamber of the cylinder head and flows in the water jacket.

On the other hand, in the water-cooled horizontally opposed multi-cylinder engine, the cooling water from the water jacket below the cylinder block flows from the lower side (exhaust port side) of the cylinder head to the upper side (intake port side). Then, the walls of the combustion chambers and the plugs of the plurality of cylinders are cooled for each bank and circulated in the water jacket above the cylinder block.

[0004]

Therefore, in the water-cooled horizontally opposed multi-cylinder engine, if the cooling water is circulated at the same flow rate as the water-cooled in-line engine, the flow velocity of the cooling water in the water jacket of the cylinder head becomes low. Therefore, there is a problem that the cooling effect becomes worse than that of the water-cooled in-line engine. On the other hand, in order to circulate more cooling water, it is possible to use a large-capacity water pump. However, using a large-capacity water pump causes a large drive loss, deteriorates performance, and is disadvantageous in terms of cost. Become.

Therefore, it is conceivable to provide a rib at a necessary portion in the water jacket of the cylinder head to increase the flow velocity. However, this rib causes air to stay in the cooling water passage, and for the first time, the cooling water in the engine cannot be used. When water is injected, there is a possibility that problems may occur such as the air in the water jacket of the cylinder head not escaping.

For example, in Japanese Unexamined Patent Publication No. 61-149551, a rib extending downward from the upper deck into the water jacket to increase the rigidity of the cylinder head is provided with a through hole for preventing air retention. The technology formed is shown. In the engine shown in this technique, the air in the cooling water is easily collected in a predetermined portion of the rib, and therefore, by forming a through hole in this rib portion, the retention of air can be easily prevented. However, in a water-cooled horizontally opposed multi-cylinder engine, the engine is installed horizontally and the cooling water flows from the lower side to the upper side of the water jacket of the cylinder head.Therefore, a rib is formed in the water jacket of the cylinder head. When formed, it is difficult to determine the position of the air retention prevention holes.

Further, when the rib is provided in the water jacket of the cylinder head, the cylinder head is a casting, so it is necessary to consider degassing at the time of casting.

The present invention has been made in view of the above circumstances, and a rib is provided in the water jacket of the cylinder head, which has good water injection of cooling water, prevents air retention, and is excellent in castability. A water-cooled horizontal opposed multi-cylinder engine that can circulate cooling water without using a large-capacity water pump and efficiently and maximally utilize the cooling effect of the circulating cooling water to improve the cooling performance of the cylinder. The purpose is to provide a cooling water passage.

[0009]

In order to achieve the above object, a cooling water passage of a water-cooled horizontally opposed multi-cylinder engine according to claim 1 of the present invention uses cooling water from a water jacket below a cylinder block of a cylinder head. In the cooling water passage of the water-cooled horizontally opposed multi-cylinder engine, which is circulated from the lower side to the upper side of the water jacket and is circulated to the water jacket on the upper side of the cylinder block, the inside of the water jacket of the cylinder head is moved to the upper side at approximately the center of each cylinder. Ribs for partitioning between the cylinders and the lower side are provided between the cylinders and between the cylinders and the wall surface of the water jacket, respectively, and cooling water is provided in the water jacket along the wall surface of the combustion chamber and the wall surface of the plug hole of each cylinder. A circulation port that flows from the lower side to the upper side is formed in each of the ribs, and And both ends of the rib disposed between,
Elongated air vent passages are formed along the wall surface at the water jacket wall surface side of the rib arranged between the cylinder and the water jacket wall surface.

In the above structure, the cooling water from the water jacket below the cylinder block flows into the bottom of the water jacket of the cylinder head, and the circulation ports formed in the ribs and the elongated air vents. It flows through the passage to the upper side of the water jacket and flows into the water jacket on the upper side of the cylinder block. Most of the circulated cooling water is circulated from the lower side to the upper side of the water jacket of the cylinder head through each of the circulation ports, and the cross-sectional area of the flow passage is reduced so that the combustion chamber wall surface and the plug hole wall surface of each cylinder are The flow velocity at each of these flow ports increases, so that the combustion chamber wall surface and the plug hole wall surface of each cylinder are efficiently cooled. On the other hand, the cooling water flowing from the lower side to the upper side of the water jacket of the cylinder head flows through each of the elongated air vent passages at a low flow rate but at a high flow rate. Therefore, air does not stay on both end sides of the rib arranged between the cylinders and on the water jacket wall surface side of the rib arranged between the cylinder and the water jacket wall surface. Further, even when water is injected into the engine, air does not stay. Further, when casting the cylinder head, the ribs are complicated in the water jacket of the cylinder head, but the elongated air vent passages function as gas vent holes, which ensures reliable venting of gas during casting. To be done.

Next, the cooling water passage of the water-cooled horizontally opposed multi-cylinder engine according to claim 2 of the present invention is the cooling water passage of the water-cooled horizontally opposed multi-cylinder engine according to claim 1, wherein the combustion of the flow port is performed. The chamber wall surface portion is formed according to the shape of the inside of the combustion chamber of each cylinder.

The portion of the wall surface of the combustion chamber of the circulation port is formed in conformity with the shape of the inside of the combustion chamber of each cylinder, so that the wall surface of the combustion chamber is formed thin and the cooling water flowing through the circulation port is formed. Can be used for efficient cooling.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 to 3 relate to an embodiment of the present invention, FIG. 1 is a sectional view taken along the line I-I of FIG. 3 illustrating a cooling water passage of a cylinder head, and FIG. 2 is a cooling water passage of a water-cooled horizontally opposed multi-cylinder engine. And FIG. 3 is a sectional view taken along line III-III in FIG. 1 for explaining the cooling water passage of the cylinder head.

In these drawings, reference numeral 1 is a water-cooled horizontally opposed four-cylinder engine. Cylinder heads 4 and 5 are attached to the outside of the left and right cylinder blocks 2 and 3 of the engine 1 via a head gasket (not shown). Has been.

Water jackets 6 and 7 are formed on the lower side of the cylinder blocks 2 and 3, water jackets 8 and 9 are formed on the upper side, and water jackets 10 and 11 are formed on the cylinder heads 4 and 5. Are formed.

The water jacket 10 of the cylinder head 4 has a lower water jacket 6 on the lower side via a communication hole 12 and an upper water jacket on the cylinder block 2 on the upper side via a communication hole 13. It is in communication with 8.

The water jacket 11 of the cylinder head 5 has a lower water jacket 7 on the lower side through a communication hole and a lower water jacket 7 on the cylinder block 3 on the upper side, and an upper water jacket of the cylinder block 3 on the upper side through a communication hole. It is in communication with 9.

Further, the lower water jacket 6 of the cylinder block 2 is connected to the cooling water passage 15 from the water pump 14 and the lower water jacket 7 of the cylinder block 3 by the water pump 14. The cooling water flowing into the lower water jacket 6 through the cooling water passage 15 flows from the lower water jacket 6 through the water jacket 10 of the cylinder head 4 and the upper water jacket 8 of the cylinder block 2 to the downstream side. While being circulated in the passage 16, the lower water jacket 6 passes through the lower water jacket 7 of the cylinder block 3, the water jacket 11 of the cylinder head 5, the upper water jacket 9 of the cylinder block 3, and the downstream side. Flow into passage 16 It is adapted to be.

The cylinder head 4 has a combustion chamber wall (upper wall forming a combustion chamber) 2 of two cylinders 21 and 22.
1a and 22a are formed horizontally to face the water jacket 10, and plug holes 23 for inserting spark plugs are provided at substantially centers of the combustion chamber walls 21a and 22a.
24 are formed respectively.

Further, the combustion chamber wall 21a has exhaust valve insertion holes 25, 25 for inserting two exhaust valves, and
Intake valve insertion holes 26, 26 for inserting two intake valves
Are formed, and similarly to the combustion chamber wall 22a,
Two exhaust valve insertion holes 27, 27 and two intake valve insertion holes 28, 28 are formed.

Further, bolt holes 29, 29 are provided above and below between the two cylinders 21, 22 of the cylinder head 4, and the bolt holes 3 are provided at four corners of the cylinder head 4.
0, 30, 30, 30 are provided, and the cylinder head 4 and the cylinder block 2 are connected to each other.

The plug holes 23, 24 are formed by the plug hole walls 23a, 24a, and the valve insertion holes 25, 26, 27, 28 are formed by the valve insertion hole walls 25a, 26a, 27a, 28a, respectively. The bolt hole 29 is separated from the water jacket 10 by a bolt hole wall 29a.

On the other hand, the plug hole wall 23a and the plug hole wall 24a are connected by a horizontal rib 31, and further, from the plug hole walls 23a, 24a,
The ribs 32 and 33 extend horizontally toward the wall surface forming the water jacket 10, and the inside of the water jacket 10 is divided into the lower water jacket 10a and the upper water jacket 10b by the ribs 31, 32 and 33. It is divided into

The lower water jacket is provided at the corner of the rib 31 where the plug hole wall 23a is provided on the combustion chamber wall 21a and the corner where the plug hole wall 24a is provided at the combustion chamber wall 22a. Circulation ports 34a, 34b having a small cross-sectional area are formed to connect 10a and the upper water jacket 10b.

Further, the combustion chamber wall 21a of the rib 32 is provided.
At the corner where the plug hole wall 23a is provided, a small cross-sectional area flow port 34c is formed, and at the corner where the combustion chamber wall 22a of the rib 33 is provided with the plug hole wall 24a, a small cut is made. A passage port 34d having an area is formed, and the lower water jacket 10a and the upper water jacket 10b are communicated with each other.

Further, the rib 31 has the flow port 3
An elongated air vent passage 35a is formed from 4a along the plug hole wall 23a, and an elongated air vent passage 35 is extended from the flow port 34b along the plug hole wall 24a.
b is formed.

The combustion chamber wall 21 of the flow ports 34a, 34c.
The portion a is formed in conformity with the inner shape of the combustion chamber of the cylinder 21, that is, the combustion chamber wall 21a of the cylinder 21 is formed to have the minimum thickness required for strength, and the flow port 3 is formed.
The portions of the combustion chamber wall 22a of 4b and 34d are also formed in conformity with the inner shape of the combustion chamber of the cylinder 22, that is, the combustion chamber wall 22a of the cylinder 22 is formed to have the minimum thickness required for strength.

Further, the rib 32 has an elongated air vent passage 3 along the wall 4a of the water jacket 10.
5 c is formed, and the elongated air vent passage 35 is formed in the rib 33 along the wall 4 b of the water jacket 10.
d is formed.

The water jacket walls 4a and 4b forming the water jacket 10 and the partition wall 38 between the water jacket 10 and the valve train chamber 37.
At the end of the cylinder head 4, gas vent holes 36a, 36b, 36c are formed which are closed by plugs after the cylinder head 4 is cast.

The cylinder head 5 is formed in substantially the same manner as the cylinder head 4.

Next, the operation of the above configuration will be described.
First, the cooling water introduced by the water pump 14 into the lower water jacket 6 of the cylinder block 2 through the cooling water passage 15 flows from the lower water jacket 6 toward the cylinder head 4, and from the lower water jacket 6. It flows through the lower water jacket 7 of the cylinder block 3 and is divided into a flow toward the cylinder head 5. Since the circulation of cooling water between the cylinder head 4 and the cylinder head 5 is substantially the same, the cylinder head 4 will be described in detail below.

The cooling water from the lower water jacket 6 of the cylinder block 2 flows into the lower water jacket 10a of the water jacket 10 of the cylinder head 4 through the communication hole 12.

Most of the cooling water that has flowed into the lower water jacket 10a flows through the flow ports 34a and 34b of the small cross-sectional area formed in the rib 31 and the small cross-sectional area formed in the rib 32. The water flows into the upper water jacket 10b of the water jacket 10 through the mouth 34c and the flow opening 34d having a small cross-sectional area formed in the rib 33.

Here, since the cooling water flowing into the upper water jacket 10b from the circulation port 34a has a small cross-sectional area, the position of the circulation port 34a, that is, the combustion chamber wall of the cylinder 21. The flow velocity is accelerated at the position where the plug hole wall 23a is provided at 21a.
Similarly, the flow rate of the cooling water flowing into the upper water jacket 10b from the circulation port 34b is accelerated at the position where the plug hole wall 24a is provided on the combustion chamber wall 22a of the cylinder 22, and the cooling water flows from the circulation port 34c to the above. The flow rate of the cooling water flowing into the upper water jacket 10b is increased at the position where the plug hole wall 23a is provided on the combustion chamber wall 21a of the cylinder 21, and the cooling water flowing into the upper water jacket 10b from the circulation port 34d. Is
The flow velocity is accelerated at the position where the plug hole wall 24a is provided on the combustion chamber wall 22a of the cylinder 22.

Therefore, the combustion chamber wall 2 of the cylinder 21 is
1a, the combustion chamber wall 22a of the cylinder 22, the plug hole wall 23a, and the plug hole wall 24a are efficiently cooled by most of the circulating cooling water.

In particular, the combustion chamber wall 21a of the cylinder 21,
In cooling the combustion chamber wall 22a of the cylinder 22, the cooling efficiency is further increased by forming the combustion chamber wall 21a of the cylinder 21 and the combustion chamber wall 22a of the cylinder 22 to be thin.

The cooling water flowing into the lower water jacket 10a is a small amount, but air vent holes 35a and 35b formed in the rib 31, air vent holes 35c formed in the rib 32, and the rib 33. The air flows into the upper water jacket 10b of the water jacket 10 through the air vent hole 35d formed in.

Therefore, the ribs 3 arranged horizontally are
Since the portion of 1, 32, 33 along the wall surface where the air is most likely to stay serves as the circulation port of the cooling water, the air does not stay. In addition, it is possible to prevent the accumulation of air when the water is injected into the engine for the first time.

Then, the upper water jacket 10b
The cooling water passes through the communication hole 13 and flows into the upper water jacket 8 of the cylinder block 2, cools the cylinders 21 and 22, and flows into the downstream passage 16.

On the other hand, the cooling water flowing through the lower water jacket 7 of the cylinder block 3 toward the cylinder head 5 flows through the water jacket 11 formed in the cylinder head 5 into the water jacket of the cylinder head 4. After being circulated in the same manner as in the inside of the cylinder 10, it is introduced into the upper water jacket 9 of the cylinder block 3, cools the cylinder, and is circulated in the downstream passage 16.

After that, the cooling water from the upper water jacket 8 of the cylinder block 2 and the cooling water from the upper water jacket 9 of the cylinder block 3 are combined and circulated again.

By the way, when casting the cylinder head 4 (same for the cylinder head 5), the gas generated in the water jacket 10 is generated by the air vent holes 35.
Each gas vent hole 36 through a, 35b, 35c, 35d
Since it can be pulled out from a, 36b, 36c,
Casting defects such as porosity and the like, which are generated when gas accumulates in the ribs 31, 32, 33, are prevented.

As described above, according to the embodiment of the present invention, most of the circulating cooling water is used, and each rib is formed so as to increase the flow velocity of the cooling water at the portion required for cooling. Cooling efficiency can be increased, and since the air vent holes are formed in the ribs, air does not stay, water injection to the engine is improved, and the cylinder head can be easily degassed.

[0044]

As described above, according to the present invention, in the cooling water passage of the water-cooled horizontally opposed multi-cylinder engine, the cooling water is well injected into the water jacket of the cylinder head, and the retention of air is prevented. Since the ribs are provided so that it is possible and excellent in castability, the cooling water is circulated without using a large-capacity water pump, and the cooling effect of the circulating cooling water is efficiently and maximally utilized to make a cylinder. It is possible to improve the cooling performance of. Further, the combustion chamber wall surface portion of the circulation port is formed in conformity with the combustion chamber inner shape of each cylinder, whereby the combustion chamber wall surface is formed thinly,
Cooling with the cooling water flowing through the flow port can be efficiently performed.

[Brief description of drawings]

1 is a sectional view taken along the line I-I of FIG. 3 for explaining a cooling water passage of a cylinder head according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a cooling water passage of a water-cooled horizontally opposed multi-cylinder engine according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1 for explaining the cooling water passage of the cylinder head according to the embodiment of the present invention.

[Explanation of symbols]

 1 Water-cooled horizontally opposed 4-cylinder engine 2,3 Cylinder block 4,5 Cylinder head 4a, 4b Water jacket wall 6,7 Lower water jacket 8,9 Upper water jacket 10,11 Lower water jacket 10a Lower water jacket 10b Upper water jacket 21, 22 Cylinder 21a, 22a Combustion chamber wall 23a, 24a Plug hole wall 31, 32, 33 Rib 34a, 34b, 34c, 34d Circulation port 35a, 35b, 35c, 35d Air vent passage

Claims (2)

[Claims] 1. A cooling water for a water-cooled horizontally opposed multi-cylinder engine, in which cooling water from a water jacket below a cylinder block is circulated from below to above the water jacket of a cylinder head and is circulated to a water jacket above a cylinder block. In the passage, ribs that partition the inside of the water jacket of the cylinder head into an upper side and a lower side at substantially the center of each cylinder are provided between the cylinders and between the cylinder and the water jacket wall surface, respectively, and cooling water is provided. Forms a flow port that flows from the lower side to the upper side in the water jacket along the combustion chamber wall surface and the plug hole wall surface of each cylinder in each rib, The ribs on both ends and between the cylinder and the wall surface of the water jacket have the ribs. A cooling water passage of a water-cooled horizontally opposed multi-cylinder engine, characterized in that the formation of the air vent passage of elongated along each wall surface and over motor jacket wall surface. 2. The portion of the combustion chamber wall surface of the flow port is
The cooling water passage for a water-cooled horizontally opposed multi-cylinder engine according to claim 1, wherein the cooling water passage is formed according to the shape of the inside of the combustion chamber of each cylinder.