JPH0518319A - Cooler of internal combustion engine - Google Patents

Abstract

PURPOSE:To simplify the structure of a cylinder liner by constituting it such that the inlet and outlet of a first refrigerant passage open to the topside of the cylinder liner, and that making it communicate with the second refrigerant passage inside the installed cylinder head. CONSTITUTION:In the condition that a cylinder liner 1 is set in a bore part 3, the topside 1a of the cylinder liner and the topside 3a of a cylinder block 3 accord with each other, and a cylinder head 2 is installed on the topsides 1a and 3a. An inlet and an outlet for cooling water are made in the refrigerant passage 12 of the cylinder head 2, and also two passages 12a are made, which communicate with the inlet and outlet 7b and 7c of the cooling water passage 7 cast in the cylinder liner 1. Precooled cooling water flows in the two cooling passages 12 to absorb the heat, and then, flows in the cooling passage of the cylinder liner through the inlet 7b from the passage 12a to absorb the heat of the top of the cylinder liner 1, and returns to the cooling passage 12 with the outlet 7c and is discharged out of the outlet of the cylinder head 2.

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, and more particularly to a cooling device for an internal combustion engine having a refrigerant passage inside a cylinder liner.

[0002]

2. Description of the Related Art Conventionally, regarding a technique for cooling a cylinder liner by providing a refrigerant passage inside a cylinder liner body,
For example, there is one disclosed in Japanese Patent Publication No. 47-37963. The cylinder liner disclosed in this publication is obtained by casting an annular pipe serving as a refrigerant passage in the vicinity of the piston top dead center, and forming a liner flange projecting outward on the outer peripheral portion of the cylinder liner at that portion. .. The inlet and outlet of the refrigerant to the refrigerant passage are formed on the side surface of the liner flange, and the refrigerant flows in and out from the side of the liner flange. Therefore, the cylinder liner is fitted in the bore portion of the cylinder block so that the portion of the liner flange projects above the upper end surface of the cylinder block, and the liner flange is formed by the upper end surface of the cylinder block and the lower end surface of the cylinder head. The cylinder liner is fixed by sandwiching it.

Further, the outer peripheral portion of the liner flange protruding from the cylinder block has a rigidity higher than that of the cylinder liner in order to increase the rigidity against the force in the radial direction outward of the cylinder liner due to the internal pressure during combustion. A support ring made of good material is provided.

[0004]

In the cylinder liner configured as described above, since the inlet and outlet of the refrigerant to the refrigerant passage are formed on the side surface of the cylinder liner, the liner flange protruding from the upper end surface of the cylinder block is provided. This structure is provided, and a support ring is further provided to increase the rigidity of the liner flange protruding from the upper end surface of the cylinder block, which complicates the structure of the cylinder liner.

Further, a refrigerant passage for inflowing / outflowing the refrigerant into / from the refrigerant passage in the cylinder liner is provided outside the cylinder liner, or a sealing device is provided at a connecting portion between the refrigerant passage in the cylinder liner and the external refrigerant passage. Therefore, the structure of the passage for the refrigerant flowing in and out of the cylinder liner becomes complicated.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling device for an internal combustion engine in which the structure of the cylinder liner and the structure of the passage of the refrigerant flowing into and out of the cylinder liner are simplified. ..

[0007]

In order to achieve the above object, the present invention is a cylinder in which a first refrigerant passage is provided inside a cylinder liner on the combustion chamber side and a second refrigerant passage is provided inside. In a cooling device for an internal combustion engine in which a head is provided on an upper end surface of the cylinder liner, the first refrigerant passage opens an inlet portion and an outlet portion of the refrigerant respectively on an upper end surface of the cylinder liner, and The second refrigerant passages in the mounted cylinder heads are communicated with each other.

[0008]

By providing the refrigerant inlet and outlet of the first refrigerant passage so as to open at the upper end surface of the cylinder liner, the entire cylinder liner can be fitted into the cylinder block.

By providing the refrigerant inlet and outlet of the first refrigerant passage so as to communicate with the second refrigerant passage in the cylinder head, the refrigerant flows into and out of the first refrigerant passage. It is performed continuously from the second refrigerant passage of the cylinder head, so that a new refrigerant passage for inflow and outflow of the refrigerant to and from the first refrigerant passage is not necessary.

[0010]

1 (A) and 1 (B) are a plan view and a vertical sectional view of an embodiment of a cooling device for an internal combustion engine according to the present invention.
It is to be noted that FIG. 1A is a plan view of the cylinder head 2 shown in FIG. 2B with the cylinder head 2 removed, and FIG.
1 is a sectional view taken along line Ib-Ib in FIG.

In the figure, a cylinder liner 1 is generally provided with a cooling water cooling section 4 provided in an upper portion where a combustion chamber is formed, a cooling oil cooling section 5 provided below the cooling water cooling section 4, and further provided below the cooling oil cooling section 5. And the cylindrical portion 6 formed.

The cooling water cooling section 4 has a structure in which an annular cooling water passage 7 through which cooling water for cooling the cylinder liner 1 flows is cast when the cylinder liner 1 is manufactured.

FIG. 2 shows a perspective view of the cooling water passage 7.

The cooling water passage 7 is formed of a metal material having a high rigidity such as stainless steel, and as shown in FIGS. 1 and 2, a passage portion 7a formed in an annular shape by a tube wall having a rectangular cross section, It is composed of an inlet portion 7b and an outlet portion 7c of cooling water communicating with the passage portion 7a. The inlet portion 7b and the outlet portion 7c are on the upper surface of the passage portion 7a, and have an annular passage portion 7a.
At 180 degrees opposite to each other. The sectional shape of the passage portion 7a is not limited to the rectangular shape as described above, and may be, for example, an oval shape.

The cooling water passage 7 having the above-described structure is cast from the metal forming the cylinder liner 1 in a state where the positions of the end portions of the inlet portion 7b and the outlet portion 7c are aligned with the upper end surface 1a of the cylinder liner 1. Get caught. That is, the upper end surface 1a of the cylinder liner 1 is a donut-shaped flat surface having openings for the inlet portion 7b and the outlet portion 7c.

In the cooling water cooling unit 4, the cooling water flows into the cooling water passage 7 through the inlet portion 7b, flows in the passage portion 7a in two directions, and is discharged to the outside through the outlet portion 7c. The heat of the cylinder liner 1 is absorbed by the cooling water in the passage portion 7a.

In the cooling oil cooling section 5, a plurality of annular cooling grooves 5a are provided on the outer periphery of the cylinder liner 1 in the axial direction, and two communication grooves 5b are provided to connect the cooling grooves 5a in the axial direction. They are provided on the opposite sides of 180 degrees from 1. Therefore, the cylinder liner 1 is replaced by the cylinder block 3
When fitted in the bore portion 3a of the
A passage for cooling oil is formed between a and 5b and the inner peripheral surface of the bore portion 3a. Further, in the cylinder block 3, when the cylinder liner 1 is fitted in the cylinder block 3, an inflow portion 8 and an outflow portion 9 continuous with the uppermost portion of the communication groove 5b are formed respectively.

Therefore, in the cooling oil cooling section 5, the cooling oil flows in from the inflow section 8 and is distributed to each cooling groove 5a through the one communication groove 5b, and the heat of the cylinder liner 1 is transferred in the cooling groove 5a. It is absorbed, flows into the other communication groove, and is discharged from the outflow portion 9. The outer diameter of the cooling oil cooling section 5 is
The size is slightly smaller than the outer diameter of the cooling water cooling unit 4.

The cylindrical portion 6 is formed in a cylindrical shape having an outer diameter dimension smaller than the bottom diameter of the cooling groove 5a. Since the cylindrical portion 6 is separated from the combustion chamber in the vicinity of the cooling water cooling portion 4, the heat input amount is small, and cooling devices such as the cooling water cooling portion 4 and the cooling oil cooling portion 5 are not provided. ..

The inner peripheral surface 1b of the cylinder liner 1 is formed to have the same inner diameter at any of the cooling water cooling section 4, the cooling oil cooling section 5 and the cylindrical section 6.

In the cylinder block 3, the position of the step between the cooling water cooling part 4 and the cooling oil cooling part 5 on the outer peripheral part of the cylinder liner 1 and the position of the step between the cooling oil cooling part 5 and the cylindrical part 6 and A bore portion 3a having a step corresponding to the size is formed, and the cylinder liner 1 having the above-described configuration is used in the bore portion 3a.
It is fitted in a.

In the cylinder liner 1 of this embodiment,
The inlet portion 7b and the outlet portion 7c of the cooling water passage 7 are provided so as to open on the upper end surface 1a of the cylinder liner 1 as described above, and nothing is formed on the side surface of the cooling water cooling portion 4. Therefore, as shown in FIG. 1 (B), the entire cylinder liner 1 is completely covered with the bore portion 3a of the cylinder block 3.
It can be fitted inside. Therefore, the structure of the upper part of the cylinder liner 1 is simplified as compared with the conventional configuration in which the liner flange is provided to open the inlet and the outlet to the side of the cylinder liner.

As described above, in this embodiment, when the cylinder liner 1 is fitted in the bore 3a, the upper end surface 1a of the cylinder liner 1 and the upper end surface 3b of the cylinder block 3 are aligned with each other. It will be composed.

The upper portions of the upper end surfaces 1a and 3b are shown in FIG.
As shown in (B), the cylinder head 2 has a gasket 1
It is attached via a tightening screw (not shown) through 3. Then, the inner surface 2a of the cylinder head 2, the upper end surface of the piston (not shown) that has moved to near the top dead center,
A combustion chamber 11 is formed by the inner peripheral surface 1b of the cylinder liner 1.

Since the cylinder head 2 forming the combustion chamber 11 has a very high temperature like the upper portion of the cylinder liner 1, a coolant passage 12 for cooling water is also formed in the cylinder head 2. An inlet portion and an outlet portion (not shown in the figure) of cooling water are formed in the refrigerant passage 12, and an inlet portion 7b and an outlet portion of the cooling water passage 7 cast into the cylinder liner 1 are formed. Two communication passages 12 communicating with 7c
a (a communication passage communicating with the outlet portion 7c is not shown)
Are formed. Conversely, the positions of the cooling water inlet 7b and outlet 7c in the cylinder liner 1 are the positions corresponding to the two communication passages 12a of the cylinder head 2.

Therefore, the pre-cooled cooling water flows through the refrigerant passage 12 of the cylinder head 2 having a high temperature to absorb the heat of the cylinder head 2, and then the cylinder liner 1 from the communication passage 12a through the inlet portion 7b. Flow into the cooling water passage 7 and absorb the heat of the upper portion of the cylinder liner 1 in the cooling water passage 7 as described above, and then return to the refrigerant passage 12 through the outlet portion 7c again to be installed in the cylinder head 2. Is discharged from the outlet.

As described above, the cooling water passage 7 of the cylinder liner 1 is in communication with the refrigerant passage 12 of the cylinder head 2 as described above, and the cooling water is circulated through the refrigerant passage 12, so that the cooling water is circulated. It is not necessary to provide a special refrigerant passage for the passage 7 outside the cylinder liner 1, and
The gasket 13 between the cylinder liner 1 and the cylinder head 2 can also serve as a seal for the connecting portion between the cooling water passage 7 and the refrigerant passage 12. For this reason, in the cooling device 10 of the present embodiment, the structure of the passage through which the cooling water flows in and out of the cooling water passage 7 is significantly simplified as compared with the conventional structure.

Further, according to the cooling device 10 of this embodiment,
As described above, the entire cylinder liner 1 is completely fitted into the bore portion 3a of the cylinder block 3.
That is, since the upper portion of the cylinder liner 1 which constitutes the combustion chamber 11 is also fitted in the bore portion 3a, the force exerted to the outside in the radial direction of the cylinder liner 1 by the internal pressure in the combustion chamber during combustion is the cylinder block 3a. Supported by. As a result, the wall thickness of the cylinder liner 1 can be reduced in the upper portion of the cylinder liner 1 where the highest rigidity is required, without impairing the rigidity of the cylinder liner 1, and thus the diameter of the cylinder liner 1 can be reduced. Can be made smaller. Further, since the internal pressure at the time of combustion is supported by the cylinder block 3 as described above, the support ring conventionally required for increasing the rigidity of the liner flange becomes unnecessary, and the cylinder liner 1 of the present embodiment is eliminated.
The shape of is further simplified.

In the cooling water cooling section 4, which is the upper part of the cylinder liner 1, there is provided a cooling water passage 7 made of a metal material having high rigidity as described above. Therefore, the rigidity of the portion of the cooling water cooling section 4 above the cylinder liner 1 is increased, which also makes it possible to reduce the diameter dimension of the cylinder liner 1.

In general, oil has a lower specific heat than water and has a low cooling effect. Therefore, the cooling oil cooling section 5 of the cylinder liner 1 is connected to the cylinder head 2 and the cooling water cooling section 4 of the cylinder liner 1. It is designed to have a lower cooling effect. Further, as described above, the cylinder liner 1 is not cooled at all in the cylindrical portion 6. Here, the heat input distribution of the cylinder liner 1 is highest in the region of the combustion chamber 11 and gradually lowers downward in the axial direction. Therefore, the cylinder liner 1 having the above configuration can perform cooling corresponding to the heat input distribution of the cylinder liner 1, and can make the temperature of the inner peripheral surface 1b of the cylinder liner uniform.

Further, since the cooling water flows in the cooling water passage 7 formed in a case shape in advance, the cooling water and the cooling oil do not mix with each other. The durability of the cylinder liner 1 can be improved as compared with the conventional example in which a sealing device such as a ring is provided.

As described above, according to the cooling device 10 for the internal combustion engine of this embodiment, the cooling water is provided on the upper portion of the cylinder liner 1.
Cooling oil can be used in the lower part to perform cooling corresponding to the heat input distribution of the cylinder liner 1, which has excellent knock resistance, and because of the structure of the upper part of the cylinder liner 1 and the inflow and outflow of cooling water into the cylinder liner 1. The structure of the passage can be simplified. Further, since the entire cylinder liner 1 including the combustion chamber 11 is fitted in the bore portion 3a of the cylinder block 3, the liner flange is the most protruded compared to the conventional configuration in which the upper end surface of the cylinder block is projected. In the upper portion of the cylinder liner 1 which requires rigidity, the wall thickness dimension of the cylinder liner 1 can be reduced without impairing the rigidity, and the diameter dimension of the cylinder liner 1 can be reduced.

Further, since the inlet portion 7b and the outlet portion 7c of the cooling water passage 7 are provided on the upper surface of the cooling water passage 7 and so as to open on the upper end surface 1a of the cylinder liner 1, cooling is performed. When air bubbles are mixed in the water passage 7, the air bubbles surely escape into the refrigerant passage 12 of the cylinder head 2, so that the cooling water cooling unit 4 of the cylinder liner 1 having the highest temperature.
Further, it is possible to prevent the generation of heat spots due to the accumulation of bubbles.

FIG. 3 is a plan view of an embodiment in which the cooling device according to the present invention is applied to an internal combustion engine having a narrow space between cylinders.

As shown in the figure, when the distance between the cylinders is small, the passage portion 22a of the cooling water passage 22 provided in the cooling water cooling portion 21 is radially arranged at the portion where the cylinder liner 20 is adjacent. It has a narrowed shape. Further, the inlet 22b and the outlet 2 of the cooling water passage 22
2c are provided facing each other in a direction orthogonal to the column direction of each cylinder liner 20 and not affected by the adjacent cylinder liners 20, and ensure a necessary opening area. Then, the cooling water cooling unit 21 includes the cooling water passage 2
Since 2 is narrowed as described above, the adjacent cylinder liner 20
The outer peripheral portion adjacent to is cut off, and the adjacent cylinder liners 20 are joined to each other, which corresponds to narrowing the interval dimension between the cylinders.

By configuring the cylinder liner 20 as described above, it is possible to obtain the same effect as that of the above-described embodiment in the case of the normal spacing, even when the spacing between the cylinders is narrow.

[0037]

As described above, according to the present invention, the entire cylinder liner including the upper portion of the cylinder liner that forms the combustion chamber can be completely fitted into the cylinder block, so that the liner flange in the conventional configuration is used. In addition, the support ring is not required, the structure of the cylinder liner can be simplified compared to the conventional structure, and the wall thickness of the cylinder liner can be reduced without affecting the rigidity of the cylinder liner. It is possible to reduce the diameter dimension of the compared to the conventional one.

Further, the inflow and outflow of the refrigerant into and out of the first refrigerant passage are continuously performed from the second refrigerant passage of the cylinder head, and at the connecting portion between the first refrigerant passage and the second refrigerant passage. Since the seal is also used as the seal between the cylinder liner and the cylinder head, the structure of the passage for inflowing and outflowing the refrigerant into and from the first refrigerant passage can be significantly simplified as compared with the conventional structure.

Further, when air bubbles are mixed in the first refrigerant passage, the air bubbles are first opened on the upper end surface of the cylinder liner.
Since it surely escapes through the inlet and outlet of the refrigerant passage, it is possible to prevent the generation of a heat spot due to the accumulation of bubbles in the upper part of the cylinder liner, which has the highest temperature.

[Brief description of drawings]

FIG. 1 is a structural diagram of an embodiment of a cooling device for an internal combustion engine according to the present invention.

2 is a perspective view of a cooling water passage in the cylinder liner shown in FIG. 1. FIG.

FIG. 3 is a plan view of an embodiment in which the cooling device according to the present invention is applied to an internal combustion engine having a narrow gap between cylinders.

[Explanation of symbols]

 1,20 Cylinder liner 1a Upper end surface 1b Inner peripheral surface 2 Cylinder head 3 Cylinder block 3a Bore part 4,21 Cooling water cooling part 5 Cooling oil cooling part 5a Cooling groove 5b Communication groove 6 Cylindrical part 7,22 Cooling water passage 7a, 22a passage part 7b, 22b inlet part 7c, 22c outlet part 8 inflow part 9 outflow part 10 cooling device for internal combustion engine 11 combustion chamber 12 refrigerant passage 12a communication passage 13 gasket

Claims (1)

Claim: What is claimed is: 1. A first refrigerant passage is provided in an upper portion of a cylinder liner on the combustion chamber side, and a cylinder head having a second refrigerant passage is provided on an upper end surface of the cylinder liner. In the cooling device for an internal combustion engine, the first refrigerant passage has an inlet portion and an outlet portion of the refrigerant opened to an upper end surface of the cylinder liner, respectively, and the inside of the mounted cylinder head. A cooling device for an internal combustion engine, wherein the cooling device is configured to communicate with each of the second refrigerant passages.