JP2745868B2 - 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) in accordance with 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 providing a plurality of openings for the communication passages of each circulation groove.

[0012]

According to the present invention, there is provided a cylinder liner formed between a cylinder block and a cylinder liner fitted to the cylinder block along a circumferential direction of the cylinder liner. A plurality of annular passages formed in the axial direction, and first and second annular passages extending in the axial direction of the cylinder liner and provided to communicate between the plurality of annular passages at positions different from each other. Internal combustion having a communication passage, a refrigerant inlet for supplying refrigerant to the first communication passage, and a refrigerant outlet for discharging refrigerant passing through the plurality of annular passages and the second communication passage. In the cooling device of the engine, the refrigerant introduced from the refrigerant introduction port and passing through the first communication passage is not in at least the extending direction of the refrigerant introduction port in the plurality of annular passages, and of Is provided with a plurality of openings to the refrigerant inlet portion of the annular passage that is introduced is first diverted to a direction substantially orthogonal to the extending direction of the passage.

[0013]

In the present invention, at least a predetermined annular passage into which the refrigerant is first introduced in a direction substantially orthogonal to the extending direction of the first communication passage and the refrigerant is introduced, among the plurality of annular passages,
Since the refrigerant passing through the first communication passage is introduced through the plurality of openings, the refrigerant can be more positively introduced into the refrigerant introduction portion of the predetermined annular passage than in the related art.

[0014]

FIG. 1 is an enlarged sectional view of a main part of an embodiment of a cooling device for an internal combustion engine according to the present invention. 5, the same components as those of FIG. 5 are denoted by the same reference numerals, and the description thereof will be omitted. In the present embodiment, a hollow cylindrical spacer 11 having a structure as shown in FIG. 2 is fitted in a vertical groove 5 which is a first communication passage communicating with a refrigerant inlet 7.

The spacer 11 is, as shown in FIGS.
Opening 12 is provided which communicates with the refrigerant inlet port 7, and the first opening 13 rectangular communicating with the annular groove 3 _1, the annular groove 3
The second opening 14 _{1-14 3} rectangular three communicating with ₂
When, third opening 1 rectangular two communicating with the annular groove 3 ₃
5 is ₁ and 15 ₂ Togaotto s bored.

[0016] Here, the refrigerant annular groove 3 ₁ top of the annular groove 3 ₁ to 3 ₃ are introduced from the refrigerant inlet port 7, in a refrigerant passage that is introduced without being bent almost channel, wherein opening 13 is formed to have an inlet and an equivalent area of the annular groove 3 _1. Further, the second and subsequent annular groove 3 ₂ and 3 ₃ from the top with no annular groove on the extending direction of the refrigerant inlet 7, of which the annular groove 3 ₂ flutes 5 is introduced from the refrigerant inlet port 7 refrigerant through which, in the refrigerant passage is introduced is first diverted to a direction substantially orthogonal to the extending direction of the circumferential groove 5, also annular groove 3 ₃ refrigerant in a direction substantially perpendicular to the extending direction of the longitudinal grooves 2 This is the refrigerant passage that is divided and introduced first.

[0017] The annular groove 3 ₂ is communicated with the inner spacer 11 through an axial opening 14 _{1-14 3} 3 in drilled rectangular (extending direction of the longitudinal groove 5) of the spacer 11 You. The annular groove 3 ₃ above, the axial two (the longitudinal grooves extending direction of 5) drilled rectangular opening 1 of the spacer 11
5 through the ₁ and 15 ₂ is communicated with the inner spacer 11.

Next, the operation of the present embodiment will be described.
Refrigerant introduced into the refrigerant inlet 7 enters into the spacer 11 through the opening 12 of the spacer 11, while flowing into the annular groove 3 ₁ through the first opening 13 without being bent almost channel, some The inside of the spacer 11 is shown in FIGS.
It flows downward. In the course refrigerant which flows through the spacer 11 downward, the second opening 14 _{1-14 3} around with substantially bent at a right angle to the flow channel second opening 14 ₁ to 1
4 ₃ is introduced into the annular groove 3 ₂ through, and the third opening 1
5 ₁ and 15 third bent flow path at a substantially right angle in the vicinity of ₂
Through the opening 15 ₁ and 15 ₂ are introduced into the annular groove 3 _3.

The refrigerant introduced into each of the annular grooves 3 _{1 to} 3 ₃ and thereafter passes through the same path as the above-described conventional device, and is drawn out from the refrigerant outlet while cooling the wall of the cylinder liner 2. .

[0020] Here, a conventional annular groove 3 _2, 3 stagnation of the refrigerant that occurs in the _third refrigerant inlet portion, as indicated by c and d in FIG. 6, each of the annular grooves 3 ₂ by the inertia of the flow of the refrigerant, 3 _It does not occur at the bottom of ₃ but occurs at the top. Thus, according to this embodiment, since the upper portion of the annular groove 3 _2, 3 ₃ is adapted actively refrigerant through the opening 14 _1, 15 ₁ is introduced, the occurrence of stagnation is prevented . Thus, overheating due to stagnation can be prevented.

Further, in this embodiment, as the annular groove close to the cylinder head of the plurality of annular grooves, because the total cross-sectional area of the refrigerant is introduced through an opening which is large, the annular groove 3 ₁ to 3 ₄
Even when the respective cross-sectional areas are the same, the larger the flow rate of refrigerant flows in the annular groove closer to the cylinder head. Thereby, it is possible to distribute the flow rate between the annular grooves in accordance with the heat input distribution such that the temperature is higher as the wall surface of the cylinder liner 2 is closer to the cylinder head. it can.

Further, by changing the opening of the spacer 11,
Even if the same cylinder liner is used in another internal combustion engine, the wall vortex distribution can be optimized.

Next, another embodiment of the present invention will be described. FIG. 3 is a structural sectional view of an example of a cooling device for an internal combustion engine proposed by the present inventor in Japanese Patent Application No. 3-135147 to which another embodiment of the present invention is applied. In the figure, the same components as those of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. 3, the longitudinal grooves 21 communicating the annular grooves 3 ₁ to 3 ₄ (not shown) in the axial direction of the cylinder liner 2 is a longitudinal groove 6 180
° formed at a distance.

A water jacket 23 and a water jacket 23 are provided on the cylinder head 22 located on the upper surface of the cylinder block 1.
A combustion chamber 24, passages 25 and 26, etc. are formed.
Further, the annular groove 3 ₁ located closest to the cylinder head 22 side.
A coolant inlet 27 is provided in the cylinder head 22 so as to extend the vertical groove 21 further in the cylinder head direction and communicate with the extending portion of the vertical groove 21.
The coolant inlet 27 is also connected to the water jacket 23.

According to the proposed device having such a structure, the refrigerant (here, cooling water) introduced into the refrigerant inlet 27 through the water jacket 23 flows through the vertical groove 21 in the downward direction (I direction) in FIG. with, and flows along the way is branched into each of the annular passage by an annular groove 3 ₁ to 3 _4. The refrigerant flows in the annular passage in the direction indicated by II in the drawing along the outer peripheral surface of the cylinder liner 2 while absorbing the heat of the wall surface of the cylinder liner 2 and then flows into the vertical groove 6.

The refrigerant flowing into the vertical groove 6 through each of the annular passages is joined by the vertical groove 6 as shown by III in FIG. 3 and proceeds upward in the figure, and thereafter is guided to the refrigerant outlet 8. Leaked.

According to the proposed device, the cylinder
Annular groove 3 located on the pad 22 side₁To cylinder
The refrigerant is introduced from the refrigerant introduction port 27 located on the side of the pad 22.
The annular groove 3₁Is in the direction in which the refrigerant inlet 27 extends.
Not the other annular groove 3_Two~ 3 _FourAs in the case of the refrigerant 21
Is introduced by being diverted in a direction substantially perpendicular to the extending direction of the
Medium passage, in which the refrigerant is divided first.
Refrigerant passage.

Another embodiment of the present invention applied to such a proposed device is shown in FIG.
A hollow cylindrical spacer 3 similar to the spacer 11 is provided therein.
Reference numeral 1 denotes a fitted structure. Here, the spacer 31 has four rectangular openings 32 _{1 to} 32 ₄ formed in the axial direction.
Communicates with the annular groove 3 ₁ through. The spacer 31 has a rectangular opening 32 ₁ formed by three holes in the axial direction.
To 32 ₃ is communicated with the annular groove 3 ₂ via, in communication with the annular groove 3 ₃ through the axial two to drilled rectangular openings 34 _1, 43 _2.

Thus, according to the present embodiment, the refrigerant introduced from the refrigerant inlet 27 is supplied to the inside from the upper part of the spacer 31 and flows through the spacer 31 downward in FIG. through the openings 321 _to 323 ₄ are distributed in an annular groove 3 _1, the opening of the spacer 31 33 _to 333
₃ through distributed into the annular groove 3 _2, it is further distributed through the apertures 34 _1, 34 ₂ of the spacer 31 to the annular groove 3 _3.
At this time, no spacer 31, when only the vertical grooves 21, the largest stagnation easily occurs annular groove 3 ₁ of the refrigerant introduction section, the openings 321 _to 323 ₄ of the spacer 31, also actively thereon Since the refrigerant is introduced into the air, the generation of stagnation can be prevented. The occurrence of stagnation can be prevented in the same manner even additional annular groove 3 _2, 3 _3.

Also in the case of the present embodiment, the larger the flow rate of the refrigerant can be made to flow in the annular groove closer to the cylinder head 22 side, so that cooling corresponding to the heat input distribution of the cylinder liner 2 can be performed.

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 is prevented by providing a spacer communicating with the refrigerant introduction port and providing a plurality of openings communicating with each annular groove in the spacer.

[0032]

As described above, according to the present invention, the refrigerant is positively introduced into the refrigerant introduction portion of the annular passage in which stagnation is likely to occur in the refrigerant flow path, thereby preventing stagnation. Can prevent boiling caused by stagnation,
It has features such as being able to prevent overheating beforehand.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of an embodiment of a cooling device for an internal combustion engine according to the present invention.

FIG. 2 is a perspective view of one embodiment of a spacer which is a main part in FIG.

FIG. 3 is a structural cross-sectional view of an example of a cooling device for an internal combustion engine, filed by the present inventors, to which another embodiment of the present invention is applied.

FIG. 4 is an enlarged sectional view of a main part of another embodiment of a cooling device for an internal combustion engine according to 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]

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Cylinder liner 3 _{1 to} 3 ₄ Annular groove 5 Vertical groove (first communication path) 6 Vertical groove (second communication path) 7 Refrigerant inlet 8 Refrigerant outlet 11 Spacer 12, 13, 14 ₁ to 14 ₃ , 15 ₁ , 15 ₂ , 32 ₁
To 32 _4, 33 _to 333, 34 _1, 34 ₂ opening

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 a second communication passage extending in the axial direction of the cylinder liner and provided so as 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 that has passed through the communication path of the internal combustion engine, wherein the refrigerant that passes through the first communication path introduced from the refrigerant introduction port has at least the plurality of annular paths. A plurality of openings formed in a refrigerant introduction portion of an annular passage which is first introduced in a direction not extending in the direction in which the refrigerant introduction port extends and substantially perpendicular to the direction in which the first communication passage extends. A cooling device for an internal combustion engine, comprising: