JP3920077B2 - Air cooler for internal combustion engine with supercharger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of an air cooler to which pressurized air is supplied from a supercharger.
[0002]
[Prior art]
FIG. 7 is a longitudinal plan view of a conventional air cooler 200 for a supercharged internal combustion engine. In the air cooler 200, a plurality of fins 91 are penetrated by a plurality of cooling pipes 90 to form a cooling space between the cooling pipes 90 and the fins 91. A chamber 98 and a chamber 99 partitioned by a partition 89 are formed on the left end side of the cooling pipe 90, a cooling water supply pipe 92 is connected to the chamber 98, and a drain pipe 94 is connected to the chamber 99. Has been. The cooling water supplied from the cooling water supply pipe 92 passes through the cooling pipe 90 communicating with the chamber 98 to reach the chamber 93 (the chamber formed on the right end side of the cooling pipe 90), and further communicates with the chamber 99 from the chamber 93. The cooling water heated through the cooling pipe 90 is drained from the drain pipe 94 through the chamber 99.
[0003]
The high-temperature pressurized air that has entered the air cooler 200 from the inlet 95 is cooled when passing through a fine space formed by the fins 91 and the cooling pipe 90, and travels from the outlet 96 to the engine through the chamber 97. . By the way, the air is cooled until it enters from the inlet 95 and exits from the outlet 96, but the fins 91, the cooling pipes 90, and the like become resistance and a pressure loss occurs. Further, the volume of the cooled air is reduced, and a pressure difference is generated between the inlet 95 and the outlet 96, so that it is difficult to ensure the amount of air supplied as the engine output increases.
[0004]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide an air cooler that can reduce a pressure difference between an air inlet and an outlet.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 includes a plurality of cooling pipes 27 and cooling fins 28 through which cooling water passes, and a cooling space between the cooling pipes 27 and the cooling fins 28. In the air cooler for cooling the pressurized supply air by passing the pressurized air supplied from the supercharger, so as to reduce the pressure loss of the pressurized air flowing through the cooling fine space, The inlet area of the air inlet 21 connected to the supercharger is set larger than the outlet area of the air outlet 22, and the air circulation area gradually decreases from the air inlet 21 to the air outlet 22. It is formed as follows .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment of Invention of Claim 1)
FIG. 1 is a longitudinal plan view of an air cooler 100 according to the invention of claim 1. 2 is a cross-sectional view taken along the line II-II in FIG. Further, FIG. 5 is an air flow path diagram of the internal combustion engine provided with the air cooler 100.
[0007]
As shown in FIG. 5, the intake air is pressurized by the compressor 50 (supercharger), the pressurized air is supplied to the air cooler 100, and the air cooled by the air cooler 100 is supplied to the engine 60. This contributes to combustion, and exhaust air (exhaust gas) is discharged from the engine 60. The turbine 70 is driven by the exhaust gas, and the air taken in by the compressor 50 is compressed.
[0008]
As shown in FIG. 1, in the air cooler 100, a large number of fins 28 are arranged in parallel to the air flow direction, and a plurality of cooling pipes 27 pass through the fins 28. Both ends of the cooling pipe 27 are fixed to the air passage wall 29 via the side plates 18 and 19.
[0009]
A housing 23 is fixed to the left side of the air passage wall 29 in FIG. 1, and a housing 24 is fixed to the right side. A chamber 30 is formed between the side plate 18 and the housing 23, and a chamber 31 is formed between the side plate 19 and the housing 24.
[0010]
Further, a cooling water supply pipe 25 is connected to the housing 23, and a drain pipe 26 is connected to the housing 24. Cooling water at a low temperature (for example, about 30 ° C.) is supplied from the cooling water supply pipe 25 to the chamber 30, the cooling water passes through the cooling pipe 27 to reach the chamber 31, and the raised cooling water passes through the drain pipe 26 from the chamber 31. After that, it is discharged to the outside.
[0011]
The air inlet 21 of the air cooler 100 is supplied with high-temperature (for example, 200 ° C. to 250 ° C.) pressurized air from a supercharger (compressor 50), and the compressed air is fine between the cooling pipe 27 and the fins 28. It flows into the space, is cooled to about 50 ° C., and flows out from the air discharge port 22 to the engine 60 (FIG. 5).
[0012]
Incidentally, the flow path width x ₁ of the air inlet 21 shown in FIG. 2 passage width y ₁ of _(inlet area) and an air outlet 22 _(the outlet area), the direction of channel width x ₁ of the air inlet 21 The air inlet 21 and the air outlet 22 are smoothly connected so that the flow path width is gradually narrowed.
[0013]
The volume of the hot pressurized air decreases as it cools, and in addition, the fins 28, the cooling pipes 27, etc. act as resistances and are depressurized as they approach the air outlet 22. The flow path widths x ₁ and y ₁ take this pressure reduction into consideration, and the engine 60 is designed so that the pressure difference between the air pressure of the hot pressurized air at the air inlet 21 and the air pressure of the low temperature air at the air outlet 22 is minimized. It is arbitrarily set according to the driving mode and driving environment in FIG.
[0014]
The temperature of the pressurized air as the compression ratio is improved supercharger (compressor 50) is so increased, increasing the channel width x _{1 (inlet} area) to the flow path width y _{1 (exit} area) . It is preferable to set the difference larger for a small engine that requires high output.
[0015]
(Reference example)
FIG. 3 is a longitudinal plan view of the air cooler 110 showing a reference example . In the air cooler 110, a plurality of cooling pipes 14 pass through a large number of fins 15, and both ends of the cooling pipe 14 are fixed to the air passage wall 16 via copper plate members 17 and 32.
[0016]
Housings 5 and 6 are provided outside the plate members 32 and 17, and are respectively fixed to the air passage wall 16. A chamber 11 is formed between the plate member 32 and the housing 5. The housing 6 is provided with a partition 3, which abuts against a plate member 17, and a chamber 9 and a chamber 10 are formed between the plate member 17 and the housing 6.
[0017]
The housing 4 is fixed to the right end of the air passage wall 16. A chamber 12 surrounded by the housing 4 is formed on the right side of a large number of fine spaces formed by the cooling pipes 14 and the fins 15.
[0018]
The air flow path surrounded by the air passage wall 16 is partitioned by a partition 13, and pressurized air from the compressor 50 (supercharger) shown in FIG. A supplied air inlet 1 is formed. Further, an air discharge port 2 communicating with the engine 60 is formed at the left end below the partition 13 as viewed in FIG.
[0019]
The high-temperature pressurized air flowing in from the air inlet 1 passes through the fine space formed by the cooling pipe 14 and the fins 15 above the partition 13 and enters the chamber 12, and from the chamber 12 below the partition 13. The cooled air flows through the fine space formed by the cooling pipes 14 and the fins 15 from the air outlet 2 to the engine 60 (FIG. 5).
[0020]
A cooling water supply pipe 7 that communicates with the chamber 9 is connected to the housing 6, and a drain pipe 8 that communicates with the chamber 10 is connected to the housing 6. Cooling water having a low temperature (for example, 30 ° C.) is supplied from the cooling water supply pipe 7 into the chamber 9, and the cooling water flows into the chamber 11 through the cooling pipe 14 communicating with the chamber 9. The cooling water 14 is connected to the chamber 10 through the cooling pipe 14 communicating therewith, and the heated cooling water is discharged from the drain pipe 8.
[0021]
The flow path widths x ₂ and y ₂ described below are different from the flow path widths x ₁ and y _{1 in} FIG. 2 (x ₁ and y ₁ cannot be shown in FIG. ₁ and y ₁ are shown in FIG. 2 which is a cross-sectional view of FIG. 1), but here the same term “channel width” is used. The same applies to channel widths x ₃ and y ₃ described later.
[0022]
As shown in FIG. 3, the flow path width x ₂ and channel width y ₂ of the air outlet 2 in the air inlet 1 is not coincident, who channel width x ₂ of the air inlet 1 increases Is set to The air inlet 1 is converted into an area ratio so that the pressure difference between the hot pressurized air flowing into the air cooler 110 from the air inlet 1 and the low-temperature air discharged from the air outlet 2 is reduced. Is set to 1.3 times the area of the air discharge port 2, for example.
[0023]
Since the appropriate ratio of the area ratio varies depending on how the internal combustion engine is operated and the operating environment, the appropriate area ratio is different between internal combustion engines of the same type as well as different types of internal combustion engines. It is preferable to set an appropriate area ratio by investigating various conditions in advance.
[0024]
FIG. 4 is a longitudinal plan view of an air cooler 120 showing another reference example . The basic structure is the same as that of the air cooler 110 in FIG. 3, but in the air cooler 110, the air traveling direction is changed once in the middle (in the chamber 12), but in the air cooler 120 (in the chamber) 48 and 49) change twice. Other configurations of the air cooler 120 are basically the same as those of the air cooler 110.
[0025]
Cooling water is supplied from the cooling water supply pipe 40 into the chamber 52, and the low-temperature cooling water in the chamber 52 passes through the cooling pipe 43 communicating with the chamber 52 and flows into the chamber 53. The cooling water in the chamber 53 flows into the chamber 54 through the cooling pipe 43 communicating with the chamber 54, and the cooling water whose temperature has been raised is drained from the drain pipe 51 to the outside.
[0026]
In FIG. 4, the high-temperature pressurized air that has flowed from the air inlet 41 having the flow path width x ₃ flows into the chamber 48 while being cooled through the fine space between the cooling pipe 43 and the fins 44. Since pressurized air is sent into the chamber 48 later, the air that has been slightly cooled in the chamber 48 passes through a fine space between the fin 44 and the cooling pipe 43 within the range of the flow path width z. Reach chamber 49. The air in the chamber 49 is cooled more than the air in the chamber 48.
[0027]
The air in chamber 49 flows through the minute space between the fins 44 cooling pipe 43 which is within the range of the channel width y ₃ to the engine 60 through the air outlet 42 (FIG. 5). The air at the air outlet 42 is further cooled than the air in the chamber 49.
[0028]
Here, the flow path is such that the air pressure of the pressurized air at the air inlet 41, the air pressure in the chambers 48 and 49, and the air pressure at the air outlet 42 substantially coincide (ideally perfectly coincide). The widths x ₃ , z and y ₃ (that is, the flow path area ratio) are set.
[0029]
The air cooler 120 has higher air resistance than the air cooler 100 (FIG. 1) and the air cooler 110 (FIG. 3). Therefore, the area ratio of each flow path is set in consideration of the air resistance. Is preferred.
[0030]
The above air coolers 100, 110 and 120 can be used by being installed in an internal combustion engine provided with a supercharger (compressor 50) shown in FIG. 5, but a part of the exhaust gas shown in FIG. It can also be installed and used in an EGR type internal combustion engine that recycles. 6 includes an air cooler for cooling the exhaust air in addition to FIG. 5. The air coolers 100, 110, and 120 shown in FIGS. 1, 3, and 4 are also applied to this air cooler. be able to.
[0031]
【The invention's effect】
According to the first aspect of the present invention, since the ratio of the air inlet area to the outlet area is set so as to reduce the pressure loss, the air compression efficiency of the supercharger (compressor 50) can be improved. It can cope with high output well.
[0032]
Since the cooling effect can be improved, the outlet temperature is reduced to about 50 ° C. even when the compression ratio of the supercharger (compressor 50) is improved and the temperature of the pressurized air is increased as the output of the engine 60 is increased. Can be set.
[0034]
The air cooler 100 according to the present invention can be configured by modifying the existing internal combustion engine as well as the existing internal combustion engine, and the compression efficiency of the supercharger (compressor 50) can be improved. It is possible to cope with a high output of 60.
[Brief description of the drawings]
FIG. 1 is a longitudinal plan view of an embodiment of an air cooler according to the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a longitudinal plan view of an air cooler showing a reference example .
FIG. 4 is a longitudinal plan view of an air cooler showing a reference example .
FIG. 5 is an air flow path diagram of the internal combustion engine.
FIG. 6 is an air flow path diagram of an internal combustion engine using EGR.
FIG. 7 is a longitudinal plan view of a conventional air cooler of a supercharged internal combustion engine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air inlet 2 Air outlet 3 Partition 4-6 Housing 7 Cooling water supply pipe 8 Drain pipe 9-12 Chamber 13 Partition 14 Cooling pipe 15 Fin 16 Air passage wall 21 Air inlet 22 Air outlet 23, 24 Housing 25 Cooling water supply pipe 26 Drain pipe 27 Cooling pipe 28 Fin 29 Air passage wall 30, 31 chamber 40 Cooling water supply pipe 41 Air inlet 42 Air outlet 43 Cooling pipe 44 Fin 45 Air passage wall 46, 47 Housing 48, 49 Chamber 50 Compressor (supercharger)
51 Drain pipe 52-54 Chamber 55 Partition 60 Engine
100 air cooler

Claims (1)

A plurality of cooling pipes 27 and cooling fins 28 through which cooling water passes are built in, and pressurized air supplied from a supercharger is passed through a fine cooling space between the cooling pipes 27 and the cooling fins 28. In the air cooler for cooling the pressurized supply air,
While setting the inlet area of the air inlet 21 connected to the supercharger to be larger than the outlet area of the air outlet 22 so as to reduce the pressure loss of the pressurized air flowing through the cooling fine space , An air cooler for an internal combustion engine with a supercharger, wherein the air flow area is gradually reduced from the air inlet 21 to the air outlet 22 .

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