JPH0128290Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a cooling system for a liquid-cooled internal combustion engine, and particularly relates to an improvement in the structure of a coolant passage in a cylinder block.

Generally, in internal combustion engines for automobiles, most of the engine is cooled by water cooling using a coolant (hereinafter referred to as "cooling water") that is forcibly circulated by a water pump.

For example, as shown in Figures 1 and 2 (see Utility Model Application No. 55-41506, etc.), cooling water is supplied from the cylinder block 1 to the cylinder head 2, surrounding each cylinder 3, combustion chamber 4, etc. The water is fed through the provided water jackets 5 and 6, and then passed through the radiator inlet passage 7 to the radiator 8 provided at the front of the engine. (not shown), the cooling water is transferred from the radiator outlet passage 9 to the cylinder block 1 again by a water pump 10 interposed in the middle of the passage 9.
The engine is cooled by circulation.

A thermostat 11 is interposed in the middle of the radiator inlet passage 7, and controls the amount of water flowing into the radiator 8 according to the cooling water temperature so that the cooling water temperature is always the optimum temperature for the engine (80 to 90°C). control.

By the way, in the case of such a cooling system, the cooling water from the radiator 8 enters the water jacket 5 from the cylinder block 1 of the front cylinder of the engine, and is then sequentially guided around the cylinder bore of the rear cylinder. Since the passages 12 provided at the top of the cylinder block 1 between the cylinders are guided to the water jackets 6 of the cylinder heads 2, the front cylinders are well cooled, while the rear cylinders are cooled poorly. The problem is that the condition deteriorates and the temperature of the combustion chamber increases.

For this reason, conventionally, as in Japanese Utility Model Publication No. 54-13443 and Japanese Utility Model Application Publication No. 56-25036, a distribution passage (water gallery) was installed on the side wall of the cylinder block to allow the cooling water from the radiator to be distributed independently to each cylinder. It has been proposed that each cylinder be cooled as evenly as possible.

However, in the case of such a conventional improvement plan, in the case of Utility Model Publication No. 54-13443, since the distribution passage is provided only on one side of the cylinder row, the cooling on the other side of the cylinder row is poor, and the other side is still There was a problem with the side overheating. On the other hand, in the case of Utility Model Application Publication No. 56-25036, distribution passages are provided on both sides of the cylinder row, which further improves cooling performance and avoids the above problem, but the engine structure becomes complicated and productivity is reduced. There was a problem in that the size and weight increased as the weight decreased.

This invention was developed by focusing on these conventional problems, and the purpose is to provide a coolant passage device for an internal combustion engine that can improve cooling performance without complicating the engine structure. do.

To this end, in this invention, in the above-mentioned liquid cooling type cooling system, one side wall of the cylinder block is connected to one side of the water jacket on the outer periphery of the cylinder through a side part port, and the cooling liquid from the radiator is connected to the side wall of the cylinder block. A side distribution passage is formed for distributing the oil to each cylinder, and an end distribution passage is formed by bending this side distribution passage along the front end wall of the cylinder block. The water jacket is characterized in that it communicates with the other side of the water jacket through an end port.

Hereinafter, embodiments of this invention will be described based on the drawings.

As shown in FIGS. 3 to 5, the feature of this embodiment is that when the water pump 10 pumps the cooling water cooled by the radiator 8 to the water jacket 5 on the outer periphery of the cylinder 3, the cylinder block This is carried out through an end distribution passage 13 provided in the front end wall of 1 and a side distribution passage 14 provided in the side wall.

The side distribution passage 14 is connected to the cylinder block 1.
(exhaust valve 1 in cylinder head 2)
5 side). In this case, the passage 14 is formed separately by a pipe and is integrally cast or press-fitted during the casting of the cylinder block.

Further, a pair of upper and lower side ports 16A, 16B are provided on the side surface of the passage 14, the number approximately corresponding to the number of cylinders.
are provided, and the cooling water is guided to the water jacket 5A on one side of the cylinder block 1 from the respective distribution ports 16A and 16B.

Of these, one side distribution port 16A opens obliquely upward on the side surface of the distribution passage 14, and connects the water jacket 6A around the exhaust valve 15 of the cylinder head 2 from the communication passage 12 provided at the top of the cylinder block 1.
The other side partial distribution port 16B opens obliquely from below the side surface of the distribution passage 14 so as to face approximately tangential to each cylinder bore, so that the cooling water that flows therein is The air is formed to circulate along the outer wall of each cylinder 3.

On the other hand, the end distribution passage 13 is provided by bending one end of the side distribution passage 14 along the front end wall of the cylinder block 1, and has a tip opening communicating with the discharge port 17 of the water pump 10. Ru.

In this embodiment, the passage 13 is formed by a gear assembly 18A integrally formed with the water pump 10 and having a semicircular cross section, and a front end wall 18B of the cylinder block to which this is joined.
Water pump 10 having the above-mentioned gear lary portion 18A
is the flange portion 18 in the gear lary portion 18A.
It is fixed to the cylinder block 1 at C.

Further, an end port 19 is provided on the side surface of the passage 13.
is provided, and the passage 1 is provided through the distribution port 19.
A part of the cooling water flowing through the cylinder block 1 directly flows into the water jacket 5B on the other side of the cylinder block 1.

The distribution port 19 is connected to the front end wall 1 of the cylinder block.
8B, it is formed to a predetermined diameter by machining with high dimensional accuracy, rather than by casting, in order to improve the accuracy of cooling water distribution.

Note that the above-mentioned end and side distribution passages 13, 14
The cross-sectional area of is set to be sufficiently large with respect to the area of each opening.

The rest of the structure is the same as in FIGS. 1 and 2, so the same members as in FIGS. 1 and 2 are given the same reference numerals and detailed explanations will be omitted.

Due to this configuration, the cooling water from the radiator 8 is first sent into the end distribution passage 13 by the water pump 10, and a portion of the water is sent to the end distribution passage 13 opened to the side of the passage 13. 19 directly into the water jacket 5B on the other side of the cylinder block 1.

On the other hand, most of the cooling water is further sent from the passage 13 to the side distribution passage 14;
A plurality of side openings 16A, 1 opened laterally.
6B to the water jacket 5A on one side of the cylinder block 1, while the passage 1
The water is also quickly distributed and introduced into the water jacket 6A around the exhaust valve 15 of the cylinder head 2 through the communication passage 12 opened above the cylinder head 3.

The cooling water introduced into the water jacket 5A on one side flows around the outer periphery of each cylinder 3 in a circular flow depending on the opening position of the distribution port 16B, etc., and then flows into the water jacket 5B on the other side. The water flows into the water jacket 6 of the cylinder head 2 through the communication passage 12 on the water jacket 5B side on the other side, where it joins with the cooling water from the end port 19 mentioned above, and is cooled at the front of the engine. After joining with the cooling water that has flowed in from the communication passage 12 on the water jacket 5A side, it is returned to the radiator 8 via the thermostat 11.

Therefore, in this embodiment, the above-mentioned side distribution passage 14 makes it possible to evenly distribute cold cooling water from the radiator 8 (that is, close to the radiator outlet temperature) to the water jacket 5 on the outer periphery of each cylinder 3. In addition, the end distribution passage 13 allows the radiator 8 to be connected to the water jacket 5B on the other side of the cylinder block 1, which is on the downstream side when viewed from the cooling water flowing through the passage 14. It is possible to directly introduce cold cooling water from the cylinder 3, thereby uniformly cooling the outer periphery of each cylinder 3 regardless of whether it is on one side or the other side. Furthermore, one distribution port 16 of the side distribution passage 14
A allows the cooling water to be directly heated without being heated via the water jacket 5 on the outer periphery of the cylinder 3.
The cooling water can be supplied to the water jacket 6A around the exhaust valve 15 of the cylinder head 2, thereby effectively lowering the temperature around the exhaust valve 15, which is particularly hot. Overcooling of the cylinder bore can also be avoided.

In this way, the cooling performance is improved, resulting in
A good cooling condition can be obtained throughout the engine, improving engine output and fuel efficiency.

This embodiment has a much simpler structure than the one disclosed in Japanese Utility Model Application Publication No. 56-25036, which has distribution passages, etc. on both sides of the cylinder row, and the engine size and weight are also much smaller and lighter. .

In addition, since the side distribution passage 14 is formed separately using a pipe, the machining accuracy of the side distribution ports 16A and 16B is increased, passage resistance is reduced, and distribution accuracy is improved. It is easier to cast the block, the manufacturing yield is reduced, and the cost is also lower. Note that the fact that the end distribution passage 13 is integrally formed with the water pump 10 also contributes to the above-mentioned improvement in productivity.

As explained above, according to this invention, the cooling performance can be improved without complicating the engine structure, and the engine output and fuel efficiency can be improved.

[Brief explanation of drawings]

Figure 1 is a sectional view of the conventional example, and Figure 2 is its A-
It is an A-line sectional view. Figure 3 is a sectional view of the embodiment of this invention, and Figures 4 and 5 are BB and C.
-C line sectional view. 10...Water pump, 8...Radiator,
1... Cylinder block, 2... Cylinder head, 5, 5A, 5B, 6, 6A... Water jacket, 3... Cylinder, 14... Side distribution passage, 16A, 16B... Side distribution port, 18B...
Cylinder block front end wall, 13... End distribution passage, 19... End distribution port.

Claims (1)

[Scope of utility model registration request] Equipped with a water pump that pumps engine coolant,
In a liquid cooling type cooling system that forcibly circulates coolant from the radiator to the water jacket of the cylinder block and cylinder head, one side wall of the cylinder block is connected to one side of the water jacket on the outer periphery of the cylinder through a side port. The cylinder blocks communicate with each other to form side distribution passages that distribute the coolant from the radiator to each cylinder, while the side distribution passages are bent along the front end wall of the cylinder block to form end distribution passages. A coolant passage device for an internal combustion engine, characterized in that the end distribution passage is communicated with the other side of the water jacket via the end distribution passage.