JP2982396B2 - 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, and more particularly to a cooling device for cooling an internal combustion engine by providing an annular groove around an outer periphery of a cylinder liner to flow a refrigerant.

[0002]

2. Description of the Related Art A cylinder block in which several cylinders are arranged, and a cylinder head located on the upper surface of the cylinder block and having a depression on the lower surface form a combustion chamber of an internal combustion engine. Further, an outer peripheral surface of the cylinder liner is fitted to an inner peripheral surface of the bore of the cylinder block. Therefore, high-temperature heat generated in the combustion chamber by the operation of the engine is transmitted to the cylinder liner and the like through the cylinder block and the cylinder head.

In order to cool the wall surface of the cylinder liner and prevent the refrigerant from boiling, a refrigerant passage is formed between the inner peripheral surface of the bore of the cylinder block and the outer peripheral surface of the cylinder liner. 2. Description of the Related Art A cooling device for an internal combustion engine by so-called groove cooling in which air flows is conventionally known (for example, Japanese Utility Model Application Laid-Open No. 63-168242).
No.).

FIG. 4 is a structural view of an example of the above-mentioned conventional cooling device for an internal combustion engine, wherein FIG. 4A is a plan view and FIG.
Shows a vertical cross-sectional view along the line BB in FIG. FIG.
(A), (B), the the outer circumferential surface of the cylinder liner 2 is fitted to the cylinder block 1 is for example 3 ₁ to 3 ₄
As shown in the figure, four annular grooves having a rectangular cross section are formed in the axial direction of the cylinder liner 2. The annular groove 3 ₁ to 3 ₄ when fitted to the cylinder liner 2 into the bore portion of the cylinder block 1, to form a refrigerant passage of an annular between the inner circumferential surface 4 of the bore portion.

The plurality of annular grooves 3 _{1 to} 3 are positioned at positions where the cylinder liner 2 and the cylinder block 1 face each other and in the axial direction (longitudinal direction) of the cylinder liner 2.
Vertical grooves 5 and 6 communicating between the _four are formed. Also,
At the position of the cylinder block 1 closest to the cylinder head, a refrigerant inlet 7 communicating with the vertical groove 5 is formed, and a refrigerant outlet 8 communicating with the vertical groove 6 is formed.

[0006] Further, it is generated in the combustion chamber, and the cylinder liner 2
In order to increase the temperature of the cylinder liner wall surface as it approaches the combustion chamber (upward in the cross-sectional view of FIG. 4B), the heat transferred to the combustion chamber is cooled so that the wall surface temperature of the cylinder liner 2 becomes uniform. to, and is about the annular groove close to the cross-sectional area of the annular groove combustion chamber, that is, _{3 4 → 3 3 → 3 2} → 3 1 small in the order.

According to the conventional cooling device of the above, the refrigerant introduced from the refrigerant inlet port 7, the longitudinal grooves 5 in FIG. 4 (B), the annular groove 3 ₁ to 3 ₃ while flowing downward from the top the refrigerant that has reached the bottom of the distributed longitudinal grooves 5 flows into the annular groove 3 ₄ the bottom. In FIG. 4 (B) a plurality of annular grooves 3 ₁ to 3 _4, the refrigerant respectively pass through the X-direction, while absorbing heat of the outer peripheral wall surface of the cylinder liner 2 in this case, and, as the upper part of the annular groove 3 Since the cross-sectional area is small, it flows at a high speed to reach the vertical groove 6, where it is assembled, and then led out of the refrigerant outlet 8 through an external radiator to a circulation pump (neither is shown).
Thereafter, the refrigerant reaches the refrigerant inlet 7 again.

As described above, according to the above-described conventional apparatus, the heat generated in the combustion chamber and transmitted to the cylinder liner 2 is converted into a velocity (a higher temperature where the temperature is higher) according to the heat input distribution on the wall surface of the cylinder liner 2. By circulating the refrigerant at (fast), the wall surface of the cylinder liner 2 can be cooled substantially uniformly.

[0009]

However, in the above-mentioned conventional apparatus, as shown in FIG. 5, the refrigerant flowing into the refrigerant introduction port 7 has the uppermost annular shape with almost no bending of the flow path through the vertical groove 5. whereas flowing into the groove 3 _1, for the top of the second and subsequent annular groove 3 _2, 3 ₃ a, the flow path as indicated by b flows bent at a right angle. However, since the refrigerant flows through the vertical groove 5 at a relatively high speed, it is difficult to change the flow path at right angles due to inertia. For this reason, the annular grooves 3 ₂ , 3
In the second and subsequent annular groove from the top is, such as ₃ stagnation occurs upstream position of the refrigerant inlet portion of the annular groove 3 _2, 3 ₃ As shown respectively in c and d in FIG. This stagnation is the largest as shown by c in the second annular groove 3 ₂ from the top tend to be relaxed as the lower part of the annular groove 3 _3, 3 _4. This is because the flow velocity of the refrigerant in the vertical groove 5 becomes lower toward the lower part as the flow rate decreases, so that the inertia effect is greatest at the upper position indicated by a, and decreases below the lower part.

When such stagnation occurs in the upper portion of the cylinder liner 2 having a large amount of heat input, the refrigerant boils, and the resulting air in the refrigerant stays in the circulation pump to reduce the output flow rate of the circulation pump. As a result, the radiator may malfunction due to cooling, which may cause overheating.

[0011] The present invention has been made in view of the above points,
An object of the present invention is to provide a cooling device for an internal combustion engine that solves the above-mentioned problem by making the shape of an opening of the annular passage on the side where the refrigerant is introduced into a predetermined shape.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to form a cylinder block between a cylinder block and a cylinder liner fitted to the cylinder block along a circumferential direction of the cylinder liner, and A plurality of annular passages formed in the axial direction of the cylinder liner, and a first annular passage extending in the axial direction of the cylinder liner and provided at different positions to communicate between the plurality of annular passages. And a second communication path, a refrigerant inlet for supplying a refrigerant to the first communication path, the plurality of annular paths and the second communication path.
In the cooling system of an internal combustion engine having a coolant outlet port for discharging the refrigerant having passed through the communicating passage, the coolant inlet port
Open directly to the uppermost annular passage of the plurality of annular passages
Connected to the first communication passage as described above , and connected to the first communication passage.
The uppermost annular portion of the plurality of annular passage openings
The opening of the annular passage excluding the passage is formed in a streamline shape along the main flow of the refrigerant flowing into the annular passage from the first communication passage.

[0013]

According to the present invention, the refrigerant flows from the refrigerant inlet to the first communication passage.
The incoming refrigerant flows into the annular passage at the top of the cylinder liner.
It goes straight and is introduced. Also, below the uppermost annular passage
The main flow of the refrigerant flowing into the annular passage flows along the streamline shape of the opening of the annular passage, so that the refrigerant flows smoothly near the opening of the annular passage.

[0014]

1 is a sectional view of a main part of a first embodiment of the present invention, and FIG. 2 is a plan view of one embodiment of a cooling device for an internal combustion engine according to the present invention. 1 and 2, on the outer circumferential surface of the cylinder liner 12 is fitted in the cylinder block 11, a plurality of annular grooves as shown in FIG. 1 _{131-134 3} are formed at equal intervals, for example. FIG. 1 shows three of the plurality of annular grooves. This cylinder liner 12
The by fitted into the bore portion of the cylinder block 11, an annular passage is formed by a bore in the peripheral surface 11a of the annular groove _{131-134 3} and the cylinder block 11. In FIG. 2, reference numeral 12a denotes an inner peripheral surface of the bore of the cylinder liner 12.

Further, the cylinder block 11 and the cylinder liner 12, longitudinal grooves 14 communicating the plurality of annular grooves, such as _{131-134 3} in the axial direction of the cylinder liner 12 is formed as the first communication path, also as shown in the plan view of FIG. 2, also annular grooves 13 ₁ to the longitudinal grooves 14 and 180 ° positions different
13 ₃ etc. flutes 15 communicating with the axial direction of the cylinder liner 12 a is formed as the second communication path.

Furthermore, on substantially the same plane as the annular groove 13 ₁ positioned closest to the cylinder head of the plurality of annular grooves,
A refrigerant inlet 16 communicating with the vertical groove 14 is formed, and a refrigerant outlet 17 communicating with the vertical groove 15 is formed. Thus, the annular groove 13 ₁ is positioned on the extending direction of the refrigerant inlet 16, also annular groove 13 _2, 13 _3, etc. at the bottom of the second and subsequent stages from the top is rolled Zaikata improved coolant inlet 16 Instead, the refrigerant is divided and introduced in a direction substantially perpendicular to the extending direction of the vertical groove 14.

The present embodiment in the cooling device of such a structure, as shown the opening of the annular groove _{131-134 3} for longitudinal grooves 14 in FIG. 1, the refrigerant flowing from the longitudinal groove 14 in the annular groove _{131-134 3} Is formed in a streamline shape along the mainstream of the above.

[0018] That is, as shown in FIG. 1, two annular grooves 13 ₁ adjacent in the axial direction of the cylinder liner 12 and 13
Cylinder liner 12 the outer peripheral wall between the ₂ is formed in the lower part streamlined shape as shown at 18 in longitudinal grooves 14 near similarly between the annular groove 13 ₂ and 13 _3, it an annular groove 13 ₃ The outer peripheral wall of the cylinder liner 12 between the adjacent lower annular groove (not shown) also has a streamline shape as indicated by 19 and 20 in the vicinity of the vertical groove 14, respectively.

Next, the operation of this embodiment will be described. The refrigerant introduced into the refrigerant inlet 16 advances to the right as shown by the solid line I in FIG. 1 and is supplied to the longitudinal groove 14, and further proceeds straight with almost no bending in the flow path as shown by II. 1
4 while being introduced into the annular groove 13 from _1, part of the refrigerant goes downward as shown within the vertical groove 14 in III, part of which is distributed in an annular groove 13 ₂ as indicated by IV, the rest is at V being dispensed into the annular groove 13 ₃ through the vertical groove 14 as shown proceeds flutes 14 downward.

The annular groove _{131-134 3} all refrigerant distributed in the annular groove of the like, absorbing heat of the outer peripheral wall surface of the cylinder liner 12 while flowing in a direction as shown by the solid line arrows VI and VII in Fig. 2, Then, after merging in the vertical groove 15, as shown by an arrow VIII, it is led out from the refrigerant outlet 17 in the direction of the circulation pump.

[0021] Here, conventionally, as described above refrigerant to be distributed to an annular groove 13 ₂ in FIG. 1 is bent in a direction in which the flow passage of the refrigerant by the inertia due to the particularly high flow velocity is perpendicular to the axial direction of the cylinder liner 12 since no Kira, stagnation occurs as shown by c in FIG. 5 to the coolant inlet upstream position of the annular groove 13 _2.

On the other hand, according to the present embodiment, the annular groove 1
3 when the refrigerant particularly fast flow rates are in the vicinity of the opening for _one of the longitudinal groove 14 is shunted into the annular groove 13 _2, as indicated by solid line arrow IV in FIG. 1, the main annular groove of the refrigerant is diverted 1
3 ₁ and 13 to flow along the wall of the streamlined shape 18 between the _two, above stagnation c does not occur. In other words, since the wall between the annular grooves is formed at the upstream position of the refrigerant inlet where the stagnation c occurs, the stagnation c does not occur.

[0023] In the same manner, a position of the refrigerant inlet upstream position of the annular groove 13 ₃ stagnation (d in FIG. 5) is generated, the annular groove 1
3 _2, for 13 ₃ between the walls is present, stagnation d does not occur. The same applies to other annular grooves not shown.

Thus, according to the present embodiment, the occurrence of stagnation can be prevented, and thus the boiling and overheating of the refrigerant, which may occur due to the occurrence of stagnation, can be prevented.

Further, in this embodiment, between the two annular grooves adjacent in the axial direction of the cylinder liner 12 of the plurality of annular grooves, such as _{131-134 3,} the walls of the vicinity of the opening for the longitudinal grooves 14 The rigidity of the wall near the opening of the annular groove with respect to the vertical groove 14 can be improved as compared with the conventional case, and the reliability can be improved.

Next, another embodiment of the present invention will be described. FIG. 3 is a sectional view showing a main part of a second embodiment of the present invention. In the figure, the same components as those of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0027] In FIG. 3, 22 is a coolant inlet port is formed on the annular groove 23 ₁ and substantially the same plane located farthest in the cylinder head. The outer peripheral surface of the cylinder liner 12 ', a plurality of annular grooves such as 23 ₁ to 23 ₃ are formed. The vertical groove 27 communicates the plurality of annular grooves in the axial direction of the cylinder liner 12 ′, and communicates with the refrigerant inlet 22.

This embodiment is basically the same as the first embodiment except that the refrigerant inlet 22 is located farthest from the cylinder head. in Figure 3 the inside longitudinal groove 27, that is diverted to the respective annular grooves 23 ₁ while flowing upwardly to 23 ₃ and the like from below differs from the first embodiment.

[0029] Here, longitudinal grooves 2, such as annular grooves 23 ₁ to 23 ₃
Since the shape of the opening with respect to 7 is formed in a streamline shape that follows the main flow of the refrigerant that is divided and introduced, the adjacent two
The wall near the opening to the vertical groove 27 between the two annular grooves is formed in a streamline shape as shown by 24 to 26 in FIG.
Therefore, in the present embodiment as well as in the first embodiment, the occurrence of stagnation can be prevented.

[0030]

As described above, according to the present invention, according to the present invention, cylindrical
The refrigerant inlet is located at the top of the Darina
Opening directly into the annular passage of the section to enhance the cooling effect
In addition, since the refrigerant introduction portion of the lower annular passage in which stagnation is likely to occur in the flow path of the refrigerant is formed in a streamline shape along the main flow of the flowing refrigerant, so that the refrigerant flows in smoothly, The stagnation can be prevented from occurring, so that the refrigerant can be prevented from boiling due to stagnation, and overheating can be prevented beforehand.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a first embodiment of the apparatus of the present invention.

FIG. 2 is a plan view of one embodiment of a cooling device for an internal combustion engine according to the present invention.

FIG. 3 is a sectional view of a main part of a second embodiment of the apparatus of the present invention.

FIG. 4 is a structural diagram of an example of a conventional cooling device for an internal combustion engine.

FIG. 5 is an explanatory diagram of a problem to be solved by the invention.

[Explanation of symbols]

11 a cylinder block 12, 12 'the cylinder liner 13 _1, 13 _2, 13 _3, 23 _1, 23 _2, 23 ₃ annular groove 14 and 27 flutes (first communication path) 15 flutes (second communication path) 16,22 Refrigerant inlet 17 Refrigerant outlet

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-1-167448 (JP, A) JP-A-63-168242 (JP, U) Patent 84904 (JP, C2) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02F 1/16 F02F 1/14 F01P 3/02

Claims (1)

(57) [Claims] An annular passage formed between a cylinder block and a cylinder liner fitted to the cylinder block along a circumferential direction of the cylinder liner, and a plurality of annular passages formed in an axial direction of the cylinder liner. A first and second communication passages extending in the axial direction of the cylinder liner and provided to communicate between the plurality of annular passages at different positions from each other; A refrigerant inlet for supplying a refrigerant, the plurality of annular passages and the second
And a refrigerant outlet for discharging the refrigerant passing through the communication passage of the internal combustion engine.
An opening of the plurality of annular passages connected to the first communication passage so as to open directly to a road;
Wherein the opening of the annular passage other than the uppermost annular passage is formed in a streamline shape along the main flow of the refrigerant flowing into the annular passage from the first communication passage. .