JP2993188B2 - 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. 5 shows a structural diagram of an example of the above-mentioned conventional cooling device for an internal combustion engine, wherein FIG. 5A 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 wall surface of the cylinder liner as it approaches the combustion chamber (upward in the cross-sectional view of FIG. 5B), the heat transferred to the cylinder liner 2 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. 5 (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. 5 (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. 6, the refrigerant flowing into the refrigerant inlet 7 is almost annular at the uppermost part without being bent 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. 6. 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 problems by setting the pressure with respect to the stagnation of each circulation groove to be equal to or higher than the mainstream pressure.

[0012]

In order to solve the above problems SUMMARY OF THE INVENTION The present invention is formed along a circumferential direction of the cylinder liner between the cylinder liner which is fitted to the cylinder block and the cylinder block, and, A plurality of annular passages formed in the axial direction of the cylinder liner, and first and second annular passages extending in the axial direction of the cylinder liner and provided so as to communicate between the plurality of annular passages at positions different from each other. a second communication path, the first refrigerant inlet port for supplying the refrigerant in the communication passage, the refrigerant outlet port for exit guide the passing through the plurality of annular passage and said second communication passage refrigerant in the cooling system of an internal combustion engine having bets, near the opening for the first communication path of said plurality of annular channels, those digits set a communication portion for communicating between adjacent fits the ring <br/> like passage .

[0013]

In the present invention, the communication portion is provided within a predetermined range between the adjacent annular passages. Therefore, in the vicinity of the opening of the annular groove through which the refrigerant is supplied through the first communication passage, the adjacent upstream side is provided. The refrigerant flowing into the annular groove is also supplied through the communication portion.

[0014]

1 is a plan view of an embodiment of a cooling device for an internal combustion engine according to the present invention, and FIG. 2 is a sectional view of a main part of a first embodiment of the device of the present invention. In FIGS. 1 and 2, an outer peripheral surface of a cylinder liner 12 fitted to the cylinder block 11 includes:
A plurality of annular grooves as shown in Figure 2 to _{131-134 3} are formed at equal intervals, for example. FIG. 2 shows three of the plurality of annular grooves. By fitting the cylinder liner 12 into the bore of the cylinder block 11,
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. 1, reference numeral 12a denotes the 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 In the plan view of FIG.
When 180 longitudinal groove 15 communicating with the axial direction of ° different annular groove 13 in positions _{1-13 3} like a cylinder liner 12 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 in FIGS. 1 and 2, _131-134 at the opening near relative vertical grooves 14 of the plurality of annular grooves _3, etc., and the coolant inlet port 16 The communication portions 18 ₁ and 18 ₂ symmetrically with respect to the straight line A within an angle range of 10 ° to 30 ° with respect to a straight line A connecting the center of the vertical groove 14 and the center of the cylinder liner 12. and characterized in that provided 18 ₃ or the like.

The communicating portions 18 ₁ to 18 ₃ are formed in annular grooves 13 ₁ and 13 ₂ , 1 adjacent in the axial direction of the cylinder liner 12.
3 ₂ 13 _3, 13 ₃ and at the cutout portion formed in the groove wall of the annular groove _{131-134 3} or the like so as to communicate s respectively between the unillustrated annular groove, the formation position the 10 ° to 30 The setting of the angle range of ° is based on an experimental result that the stagnation occurs in the angle range.

Further, the communicating portions 18 ₁ to 18 ₃ are shown in FIG.
As shown in (2), the communicating area that connects between adjacent annular grooves in the downstream direction of the refrigerant has a smaller sectional area. Therefore, the cross-sectional area of the communicating portion is the largest at 18 ₁ ,
₂ → 18 ₃ → ..., are formed so as to sequentially becomes smaller in the order of.

Next, the operation of this embodiment will be described. The refrigerant introduced into the refrigerant inlet 16 advances rightward as shown by the broken line I in FIG. 2 and is supplied to the longitudinal groove 14, and further proceeds straight without hardly bending the flow path as shown by II in the longitudinal groove. 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 in FIG. 1 by solid arrows VI and VII, 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.

[0022] Here, conventionally, as described above refrigerant to be distributed to an annular groove 13 ₂ in FIG. 2 is bent in the direction of the flow path 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. 6 to the refrigerant inlet upstream position of the annular groove 13 _2.

On the other hand, according to this embodiment, the annular groove 1
3 ₁ refrigerant particularly fast flow rates are in the vicinity of the opening for longitudinal groove 14, to flow into the refrigerant inlet upstream position of the annular groove 13 ₂ through the communication unit 18 ₁ as shown by the broken line IX in FIG. 2, the stagnation c does not occur. Similarly, the refrigerant inlet upstream position of the annular groove _{13. 3,} the refrigerant flows through the communicating portion 18 _2, stagnation as shown in d in FIG. 6 does not occur.

Therefore, according to the present embodiment, the refrigerant does not boil due to stagnation, so that overheating can be prevented. Further, since the cross-sectional area of the communication portion 18 _{1-18 3} are formed on a large enough refrigerant upstream, as an annular groove close to the cylinder head can the flow rate of the refrigerant in the large, thereby the heat input distribution in the cylinder liner 12 A suitable coolant flow distribution between the annular grooves can be obtained, and thus cooling can be performed to make the temperature of the wall surface of the cylinder liner 12 uniform.

Next, another embodiment of the present invention will be described.
FIG. 3 is a sectional view of a main part of a second embodiment of the present invention. In the figure, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 3, 21 ₁ , 21
Reference numerals ₂ and 21 ₃ denote communicating portions, respectively, and annular grooves 13 ₁ and 13 ₂ ,
Among 13 ₂ and 13 _3, 13 ₃ and 3 are formed in the groove wall of the annular groove so as to respectively communicate between the annular groove (not shown) adjacent to the lower side of the annular groove 13 _3.

As in FIG. 1, the formation positions of these communicating portions 21 _{1 to} 21 ₃ are within an angle range of 10 ° to 30 ° with respect to the straight line A, as in the first embodiment. However, as shown in FIG. 3, the communicating portions 21 _{1 to} 21 ₃
Are different from those in the first embodiment in that the cross-sectional area is the same, and the formation position is provided so that the communication portion on the downstream side of the refrigerant is located farther from the longitudinal groove 14.

[0027] In this embodiment, the generation position of the stagnation, as an annular groove in the refrigerant upstream side, considering that occur at a position close to the vertical groove 14, the generation of stagnation of the formation position of the communication unit 21 ₁ to 21 ₃ By setting according to the position, the occurrence of stagnation is prevented.

Next, a third embodiment of the present invention will be described with reference to FIG. In the figure, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.
4, between the adjacent annular grooves 13 ₁ and 13 ₂ communicating portion 31 _{1-31 3} are formed. The communicating portion between the annular groove 13 ₂ and 13 ₃ adjacent 32 ₁ and 32
₂ is formed, which further communicating portion 33 ₁ is formed between the annular groove (not shown) adjacent thereto an annular groove 13 _3.

These communication sections 31 _{1 to} 31 ₃ , 32 ₁ ,
32 ₂ and 33 ₁ 1 relative to the straight line A shown in FIG. 1
Although 0 ° from a point within the angular range of up to 30 ° is as defined above each embodiment, as shown in FIG. 4, the communicating portion 31 ₁ -
31 _3, 32 _1, 32 ₂ and are identical each cross-sectional area of 33 _1, its formed position differs from the respective embodiments.

[0030] That is, the communicating portion communicating between two annular grooves adjacent in the present embodiment, the number as those in the downstream position of the coolant are formed smaller, annular grooves 13 ₁ in the most upstream position of the coolant When 13 ₃ a communicating portion communicating a 31 ₁ ~
31 ₃ are formed three in most of the total as shown.

Thus, according to this embodiment, the annular groove 1
3 ₂ since the bottom of the annular groove of the refrigerant inlet upstream position communicating portion 31 _{1-31 3} to 32 ₁ and 32 ₂ or 33 ₁ for refrigerant flows through, stagnation described above may be so as not to generate. Further, since the flow rate of the refrigerant can be increased in the annular groove closer to the cylinder head, the temperature of the wall surface of the cylinder liner 12 can be made uniform.

The present invention is not limited to the above embodiment, but can be applied to a cooling device in which a refrigerant inlet is provided at a position farthest from a cylinder head. In this case, the refrigerant introduced from the refrigerant introduction port is distributed to the plurality of annular grooves while flowing in the vertical groove in the direction of the cylinder head, and is the furthest to the cylinder head among the annular grooves that are not on the extension of the refrigerant introduction port. The refrigerant is bent at a right angle to the axial direction of the vertical groove in the annular groove at the position, and flows at a large flow velocity, so that stagnation is most likely to occur. Therefore, even in such a cooling device, the occurrence of the above-mentioned stagnation can be prevented by providing a communicating portion that communicates between adjacent annular grooves in the vicinity of the opening to the vertical groove.

[0033]

As described above, according to the present invention, since the refrigerant is introduced through the communication portion into the refrigerant introduction portion of the annular passage in which the stagnation is likely to occur in the refrigerant passage, the occurrence of the stagnation is prevented. Therefore, it is possible to prevent boiling caused by stagnation and prevent overheating beforehand.

[Brief description of the drawings]

FIG. 1 is a plan view of one embodiment of a cooling device for an internal combustion engine according to the present invention.

FIG. 2 is a sectional view of a main part of the first embodiment of the device of 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 sectional view of a main part of a third embodiment of the device of the present invention.

FIG. 5 is a structural diagram of an example of a conventional cooling device for an internal combustion engine.

FIG. 6 is an explanatory diagram of a problem to be solved by the invention.

[Explanation of symbols]

Reference Signs List 11 cylinder block 12 cylinder liner 13 _{1 to} 13 ₃ annular groove 14 vertical groove (first communication path) 15 vertical groove (second communication path) 16 refrigerant inlet 17 refrigerant outlet 18 ₁ to 18 ₃ , 21 ₁ to 21 ₃ , 31 _{1 to} 31 ₃ , 3
2 ₁ , 32 ₂ , 33 ₁ communication part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-167448 (JP, A) JP-A 63-168242 (JP, U) JP-A 54-66008 (JP, U) (58) Field (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 refrigerant passing through the communication path of the internal combustion engine, wherein openings of the plurality of annular paths with respect to the first communication path are provided.
A cooling device for an internal combustion engine, wherein a communication portion is provided in the vicinity to communicate between adjacent annular passages .