JPH08312357A - Intercooler of internal combustion engine - Google Patents

Abstract

PURPOSE: To enable reduction of a sound pressure level of air-flow noise to be produced out of each intercooler by setting the passage length of each intake core passage so as to make the resonant frequency of a columnar vibration to be produced in each intake core passage, not accord with the characteristic frequency of an inlet system. CONSTITUTION: A core part 8 is provided with plural flat and enclosed-type tubes 12 conducting intake air, and a fresh air core passage 13 conducting the outside air to the outside of each tube 12, respectively. Each tube 12 is stacked in piles via plural pieces of corrugated platelike outer fins 18. In addition, plural pieces of intake core passages 11 conducting the intake air via an inner fin 15 are capillarily partitioned off on the inside of each tube 12. Each of these intake core passages 11 to be capillarily partitioned off via the inner fin 15 is formed in uniform passage length, and this passage length of each intake core passage 11 is optionally set up. With this constitution, the resonant frequency of columnar vibration to be produced in the intake core passages 11 is made so as not to accord with the characteristic frequency of an inlet system, whereby a sound pressure level of air-flow noise being generated is reduced to some extent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an intercooler designed to reduce noise generated from an intake system of an internal combustion engine.

[0002]

2. Description of the Related Art As an internal combustion engine having an intercooler in its intake system, there are, for example, those shown in FIGS. 8 and 9 (for example, Japanese Utility Model Publication No. 1-96530, Japanese Utility Model Publication No. 4-172).
No. 80, see).

In FIG. 8, 1 is an engine, and 2 is a turbocharger that supercharges intake air by utilizing pressure energy of exhaust gas of the engine 1.

Exhaust gas discharged from the cylinder of the engine 1 is introduced into the turbine 4 through the exhaust pipe 3. The turbine 4 rotates at high speed by the pressure energy of the exhaust gas, and rotationally drives the compressor 5 connected via the shaft.

The compressor 5 supercharges the air sucked from the intake pipe 6 in accordance with the number of revolutions of the air and supplies it to the cylinder of the engine 1 through the intake pipe 6.

An intercooler 7 is installed in the middle of an intake pipe 6 connecting the compressor 5 and the engine 1. Intercooler 7
Has a function of radiating the heat of the intake air whose temperature is increased by being compressed by the compressor 5 to the outside air. Organization 1
The intake air sent to the engine is cooled by the intercooler 7, so that knocking of the engine 1 is suppressed and intake charging efficiency is increased to achieve high output.

As shown in FIG. 9, the intercooler 7 includes a core portion 8 for promoting heat exchange between the intake air and the outside air, and an inlet tank for introducing intake air pumped from the compressor 5 to the core portion 8 as indicated by an arrow in the figure. 9 and an outlet tank 10 that collects the intake air that has passed through the core portion 8 and guides it to the engine 1 through the intake pipe 6.

As shown in FIG. 10, the core portion 8 is provided with a plurality of flat tube-shaped tubes 12 for guiding the intake air, and an outside air core passage 13 for guiding the outside air to the outside of each tube 12.

The tubes 12 are laminated via a plurality of corrugated plate-shaped outer fins 18. A heat dissipation area for the outside air flowing through the outside air core flow path 13 via the outer fins 18 is secured.

An inner fin 15 having a corrugated plate shape is provided inside each tube 12. Inside each tube 12, a plurality of intake core flow paths 11 for guiding intake air through the inner fins 15 are defined in a narrow path shape. An area in contact with the intake air flowing through the tube 12 via the inner fins 15 is secured, and heat exchange performed between the intake air and the outside air is promoted.

[0011]

By the way, the intake core passage 1 defined by a plurality of narrow passages through the inner fins 15 is formed.
In No. 1, since both ends thereof are pipelines open to the inlet tank 9 and the outlet tank 10, air column vibration occurs in the intake core flow passage 11.

The end portions 16 of the inner fins 15 are arranged side by side with the open end portions 17 of the tubes 12, and the intake core flow passages 11 defined by the inner fins 15 in the form of pipes all have uniform passage lengths. Therefore, when the resonance frequency of the air column vibration generated in each intake core flow passage 11 matches with the solid frequency of the intake system configured by the intake manifold or the like, the resonance occurs and the high frequency air flow from each intake core flow passage 11 resonates. Sound is generated and becomes noise leaking to the outside of the intercooler 1.

As a countermeasure against this, it is necessary to provide a sound insulating material 11 that covers the outside of the inlet tank 9 and the outlet tank 10 or increase the wall thickness of the inlet tank 9 and the outlet tank 10, resulting in an increase in weight.

An object of the present invention is to solve the above problems and reduce the noise generated from the intercooler of the internal combustion engine.

[0015]

An intercooler for an internal combustion engine according to a first aspect of the present invention passes through an inlet tank for introducing intake air pumped from a supercharger and the intake air introduced into the inlet tank to a cooling medium. Multiple intake core channels that promote heat dissipation of
In an intercooler of an internal combustion engine, which comprises an outlet tank that collects the intake air that has passed through each intake core flow path and guides it to the engine,
The passage length of each intake core passage is set so that the resonance frequency of the air column vibration generated in each intake core passage does not match the natural frequency of the intake system.

According to a second aspect of the present invention, in the intercooler for an internal combustion engine according to the first aspect of the invention, each intake core passage is provided with corrugated inner fins inside a flat tubular tube. The inner fin is defined and the end of the inner fin is arranged inside the tube with a predetermined offset amount L with respect to the open end of the tube.

An intercooler for an internal combustion engine according to a third aspect of the present invention includes an inlet tank into which intake air pumped from a supercharger is introduced, and a plurality of intake tanks that pass the intake air and promote heat dissipation to a cooling medium. In an intercooler of an internal combustion engine that includes an intake core flow path and an outlet tank that collects intake air that has passed through each intake core flow path to an engine, a resonance frequency of air column vibration generated in each intake core flow path Differentiate from each other.

The intercooler for an internal combustion engine according to a fourth aspect is the intercooler according to the third aspect, wherein a plurality of corrugated plates are formed inside the plurality of flat tubular tubes for the intake core passages. The inner fins are defined by the inner fins, and the lengths of the respective inner fins in the intake core flow path direction are different from each other.

According to a fifth aspect of the present invention, in the intercooler for an internal combustion engine according to the third aspect, a plurality of corrugated plates are formed inside the plurality of flat tubular tubes for the intake core passages. The tubes are defined by inner fins, and the lengths of the tubes in the intake core flow path direction are different from each other.

[0020]

In the intercooler for an internal combustion engine according to claim 1, when each intake core flow path is viewed as a pipe line whose both ends are open, the resonance frequency of the air column vibration generated in each intake core flow path is It depends on the passage length or passage cross-sectional area of the core passage.

Therefore, by arbitrarily setting the passage length of each intake core passage of the intercooler, it is possible to avoid that the resonance frequency of the air column vibration generated in each intake core passage coincides with the natural frequency of the intake system. Therefore, the sound pressure level of the air flow sound generated from the intercooler can be reduced.

In the intercooler for an internal combustion engine according to a second aspect, the intake core flow passage has a structure in which the end portion of the inner fin is arranged inside the tube with a predetermined offset amount L with respect to the opening end portion of the tube. It is possible to arbitrarily set the passage length of the intake air passage, avoiding that the resonance frequency of the air column vibration generated in each intake core passage matches the natural frequency of the intake system, and the sound pressure of the air flow sound generated from the intercooler. The level can be reduced.

Further, since the structure is such that the length of the inner fins is adjusted to reduce the sound pressure level of the air flow noise generated from the intercooler, it is not necessary to change the outer dimensions of the intercooler in accordance with the engine having a different displacement. You can increase productivity.

In the intercooler of the internal combustion engine according to the third aspect, when each intake core passage is viewed as a pipe line whose both ends are open, the resonance frequency of the air column vibration generated in each intake core passage is It depends on the passage length or passage cross-sectional area of the core passage.

Therefore, by making the passage lengths of the intake core passages of the intercooler different from each other, the resonance frequencies of the air column vibrations generated in the intake core passages are different from each other, and are equal to the natural frequency of the intake system. It is possible to suppress a sudden increase in the sound pressure level of the airflow sound generated from the intercooler.

In the intercooler for an internal combustion engine according to a fourth aspect of the present invention, by adjusting the length of each inner fin to make the passage lengths of the intake core flow paths different from each other, the intercooler can cope with engines having different displacements, etc. Productivity can be improved without changing the cross-sectional shape of the inner fins or the outer dimensions of the intercooler.

In the intercooler for an internal combustion engine according to a fifth aspect, the structure in which the lengths of the tubes are adjusted to make the passage lengths of the intake core passages different from each other is provided, so that the engines corresponding to different displacements can be accommodated. Productivity can be improved without changing the cross-sectional shape of the inner fins or the outer dimensions of the intercooler.

[0028]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 2, reference numeral 7 denotes an intercooler for cooling intake air sent from a compressor (compressor) of a turbocharger (not shown) to each cylinder of the engine.

The intercooler 7 has a function of radiating the heat of the intake air whose temperature has risen due to being compressed by the compressor to the outside air. By cooling the intake air sent to the engine by the intercooler 7, it is possible to improve the intake charging efficiency while suppressing knocking of the engine and to achieve high output.

The intercooler 7 includes a core portion 8 for promoting heat exchange between intake air and the outside air (cooling medium), an inlet tank 9 for introducing intake air pumped from the compressor 5 to the core portion 8 as indicated by an arrow in the figure, An outlet tank 10 that collects the intake air that has passed through the core portion 8 and guides it to the engine 1 through the intake pipe 6 is provided.

As shown in FIG. 1, the core portion 8 is provided with a plurality of flat tube-shaped tubes 12 for guiding intake air and an outside air core passage 13 for guiding outside air to the outside of each tube 12.

The tubes 12 are laminated via a plurality of corrugated plate-shaped outer fins 18. A heat dissipation area for the outside air flowing through the outside air core flow path 13 via the outer fins 18 is secured.

Inside each tube 12, corrugated plate-shaped inner fins 15 are provided, and inside each tube 12, a plurality of intake core flow paths 11 for guiding intake air through the inner fins 15 are provided.
Is defined as a narrow path. An area in contact with the intake air flowing through the tube 12 via the inner fins 15 is secured, and heat exchange performed between the intake air and the outside air is promoted.

By the way, since the intake core flow passage 11 defined by a plurality of narrow passages through the inner fins 15 is a pipe passage having both ends open to the inlet tank 9 and the outlet tank 10, respectively. Air column vibration occurs in the intake core flow path 11.

However, the end portion 1 of the inner fin 15
Reference numeral 6 indicates the intake core flow passages 1 that are lined up with the open end portions 17 of the tubes 12 and are formed in a tubular shape through the inner fins 15.
Since all 1 have uniform passage lengths, resonance occurs when the resonance frequency of the air column vibration generated in each intake core flow passage 11 matches the solid frequency of the intake system, and The airflow noise is generated, and the noise leaks to the outside of the intercooler 1.

In response to this, the present invention provides the inner fin 1
By setting the passage length of each of the intake core passages 11 defined in a pipe shape via 5, the intake core passages 11
The resonance frequency of the air column vibration that occurs in the cylinder should not match the natural frequency of the intake system.

In this embodiment, one end 16 of each inner fin 15 is positioned inside the one opening end 17 of each tube 12. Therefore, one end of the intake core flow passage 11 defined by a plurality of narrow passages through the inner fins 15 is open to the outlet tank 10, and the other end is between the open end portions 17 of the tubes 12. It becomes a pipeline opened to the inlet tank 9 through the inlet space 19 defined in the above.

One end portion 16 of each inner fin 15 is located inward from the one opening end portion 17 of each tube 12 with a constant offset amount L.

With the above construction, the operation will be described below.

When each intake core passage 11 is a pipe whose both ends are open, the resonance frequency f of the air column vibration generated in the intake core passage 11 is shown.
(KHz) is expressed by the following equation.

[0042]

[Equation 1]

Here, C is the speed of sound, l is the length of the conduit (m), r is the radius of the conduit (m), and k is the open end correction value.

From the above equation (1), the resonance frequency of the air column vibration generated in each intake core passage 11 depends on the length of each intake core passage 11 corresponding to the pipe length l. Therefore, each tube opening end 17 of each inner fin end 16 is
It is possible to avoid that the resonance frequency of the air column vibration generated in each intake core passage 11 coincides with the natural frequency of the intake system by adjusting the pipe length 1 by arbitrarily setting the offset amount L with respect to .

Specifically, the sound velocity C = 331 + 0.6 × 2
5 (° C) = 346 m / s ² , length of each intake core passage 11 = 160 × 10 ⁻³ (m), pipe radius r = 1,28
When × 10 ⁻³ (m) and the open end correction value k = 1.22, the resonance frequency f of the air column vibration generated in each intake core passage 11 is calculated by the following equation.

[0046]

[Equation 2]

In this case, the fifth-order resonance frequency f generated in each intake core passage 11 is f = 0.923 × 5 = 4.6.
When the natural frequency of the intake system approximates to 1 kHz,
Airflow noise generated from the intercooler 7 increases sharply.

To deal with this, as one embodiment, the offset amount L of each inner fin end 16 with respect to each tube opening end 17 is set to 7.5 mm. in this case,
Resonance frequency f of air column vibration generated in each intake core flow path 11
Is calculated by the following equation.

[0049]

(Equation 3)

In this case, the fifth-order resonance frequency f generated in each intake core passage 11 is f = 0.96 × 5 = 4.8.
It becomes 0 kHz and 0.2 k with respect to the natural frequency of the intake system.
It is possible to suppress the generation of airflow noise from the intercooler 7 due to the frequency difference of Hz.

FIG. 3 is a characteristic diagram showing the result of analyzing the sound pressure level of noise generated from the intake system of the engine. As shown by hatching in the figure, it is possible to prevent the sound pressure level of the noise generated from the intake system from rapidly increasing in a specific high frequency range due to the airflow noise generated in the intercooler 7.

As described above, the structure of adjusting the length of the inner fin 15 to reduce the sound pressure level of the airflow sound generated from the intercooler 7 changes the cross-sectional shape of the inner fin 15 and the length of the tube 12. Therefore, it is not necessary to change the outer size of the intercooler 7 according to the engine having a different displacement or the like, and the productivity can be improved.

Next, another embodiment shown in FIG. 4 will be described. The parts corresponding to those in FIG. 2 and the like are designated by the same reference numerals.

By making the passage lengths of the intake core flow passages 11 defined in the form of pipes through the inner fins 15 different from each other, the resonance frequencies of the air column vibrations generated in the intake core flow passages 11 are set to different values. Different for each tube 12.

One end portion 16 of each of the inner fins 15 is positioned inside the one opening end portion 17 of each tube 12. One end 16 of each inner fin 15 is connected to each tube 12
The offset amounts L with respect to the one opening end 17 are different from each other.

In this case, by making the passage lengths of the intake core passages 11 of the intercooler 7 different from each other, the resonance frequencies of the air column vibrations generated in the intake core passages 11 are made different, and the natural vibration of the intake system is made different. It is possible to suppress a sudden increase in the sound pressure level of the airflow sound generated from the intercooler 7 in agreement with the number.

As described above, the structure of adjusting the length of the inner fin 15 to reduce the sound pressure level of the airflow sound generated from the intercooler 7 changes the cross-sectional shape of the inner fin 15 and the length of the tube 12. Therefore, it is not necessary to change the outer size of the intercooler 7 according to the engine having a different displacement or the like, and the productivity can be improved.

Next, another embodiment shown in FIG. 5 will be described. The parts corresponding to those in FIG. 2 and the like are designated by the same reference numerals.

One end portion 16 of each inner fin 15 is formed to be inclined with respect to the passage direction of the intake core flow passage 11. Therefore, each tube 12 at one end 16 of each inner fin 15
The offset amount L with respect to the one opening end 17 gradually changes.

Also in this case, by making the passage lengths of the intake core flow passages 11 of the intercooler 7 different from each other, the resonance frequencies of the air column vibrations generated in the intake core flow passages 11 are different from each other, and the intake system has a unique resonance frequency. It is possible to suppress a sudden increase in the sound pressure level of the airflow sound generated from the intercooler 7 that coincides with the frequency.

As described above, the structure in which the length of the inner fin 15 is adjusted to reduce the sound pressure level of the airflow sound generated from the intercooler 7 changes the cross-sectional shape of the inner fin 15 or the length of the tube 12. Therefore, it is not necessary to change the outer size of the intercooler 7 according to the engine having a different displacement or the like, and the productivity can be improved.

Next, another embodiment shown in FIG. 6 will be described. The parts corresponding to those in FIG. 2 and the like are designated by the same reference numerals.

The lengths of the tubes 12 are made different from each other, and the passage lengths of the intake core passages 11 of the intercooler 7 are made different from each other.

Connect the end 17 of each tube 12 to the inlet tank 9
The amount of protrusion is increased stepwise.

The inner fins provided in each tube 12 are also different according to the length of each tube 12.

Also in this case, by making the passage lengths of the intake core passages 11 of the intercooler 7 different from each other, the resonance frequencies of the air column vibrations generated in the intake core passages 11 are different from each other, and the characteristic of the intake system is different. It is possible to suppress a sudden increase in the sound pressure level of the airflow sound generated from the intercooler 7 that coincides with the frequency.

As described above, the structure in which the length of each tube 12 is adjusted to reduce the sound pressure level of the air flow sound generated from the intercooler 7 allows the inner fin 15 to have a cross-sectional shape corresponding to an engine having a different displacement. Since there is no need to change or change the outer dimensions of the intercooler 7, productivity can be improved.

Next, another embodiment shown in FIG. 7 will be described. The parts corresponding to those in FIG. 2 and the like are designated by the same reference numerals.

In this embodiment, there is provided a perforated tube type tube 22 in which each intake core channel 11 is integrally formed.

One end 27 of each tube 22 is inclined with respect to the passage direction of the intake core flow passage 11. Therefore, the passage lengths of the intake core passages 11 opening side by side in the tubes 22 change stepwise.

Also in this case, by making the passage lengths of the intake core passages 11 of the intercooler 7 different from each other, the resonance frequencies of the air column vibrations generated in the intake core passages 11 are different from each other, and the characteristic of the intake system is different. It is possible to suppress a sudden increase in the sound pressure level of the airflow sound generated from the intercooler 7 that coincides with the frequency.

Further, the cross-sectional shape of the corrugated inner fin 15 is changed so that each intake core passage 1 of the intercooler 7 is changed.
By making the passage cross-sectional areas of 1 different from each other, the resonance frequency of the air column vibration generated in each intake core flow path 11 is different, and the sound of the air flow sound generated from the intercooler 7 in agreement with the natural frequency of the intake system is generated. It is also possible to suppress a rapid increase in pressure level.

However, in this case, if the cross-sectional shape of the inner fin 15 is changed corresponding to the engine having a different displacement, the outer dimensions of the intercooler 7 may be changed, and the productivity may be deteriorated.

[0074]

As described above, in the intercooler for an internal combustion engine according to claim 1, each intake core is arranged so that the resonance frequency of the air column vibration generated in the intake core passage does not match the natural frequency of the intake system. By setting the passage length of the flow passage, it is possible to reduce the sound pressure level of the air flow sound generated from each intercooler.

In the intercooler for an internal combustion engine according to a second aspect of the present invention, the intake core flow passage has a structure in which the end of the inner fin is arranged inside the tube with a predetermined offset amount L with respect to the open end of the tube. The passage length can be set arbitrarily, and it is possible to implement it without the need to change the outer dimensions of the intercooler according to the engine having different displacement, etc., and the productivity can be improved.

In the intercooler for an internal combustion engine according to a third aspect of the present invention, the resonance frequencies of the air column vibrations generated in the intake core passages are different by making the passage lengths of the intake core passages of the intercooler different from each other. It is possible to suppress a sudden increase in the sound pressure level of the air flow sound generated from the intercooler in agreement with the natural frequency of the intake system.

An intercooler for an internal combustion engine according to a fourth aspect of the invention has a structure in which the lengths of the inner fins are adjusted to make the passage lengths of the intake core flow paths different from each other. It can be implemented without changing the cross-sectional shape of the inner fins or the outer dimensions of the intercooler.
You can increase productivity.

The intercooler for an internal combustion engine according to a fifth aspect of the invention has a structure in which the lengths of the tubes are adjusted to make the passage lengths of the intake core flow paths different from each other. The productivity can be improved without changing the cross-sectional shape of the inner fins or the outer dimensions of the intercooler.

[Brief description of drawings]

FIG. 1 is a perspective view of a core portion showing an embodiment of the present invention.

FIG. 2 is a plan view of the intercooler.

FIG. 3 is a characteristic diagram showing a result of analyzing the sound pressure level of noise similarly generated from the intake system of the engine.

FIG. 4 is a plan view of an intercooler showing another embodiment.

FIG. 5 is a side view of an intercooler showing yet another embodiment.

FIG. 6 is a plan view of an intercooler showing still another embodiment.

FIG. 7 is a side view of an intercooler showing yet another embodiment.

FIG. 8 is a system diagram of an engine showing a conventional example.

FIG. 9 is a perspective view of the intercooler.

10 is a sectional view showing a portion A of FIG.

[Explanation of symbols]

 7 Intercooler 8 Core part 9 Inlet tank 10 Outlet tank 11 Intake core flow path 12 Tube 13 Outside air core flow path 15 Inner fin 16 Inner fin end 17 Tube opening end 18 Outer fin 19 Inlet space

Claims (5)

[Claims] 1. An inlet tank for introducing intake air pumped from a supercharger, a plurality of intake core passages for allowing intake air introduced into the inlet tank to radiate heat to a cooling medium, and each intake core flow. In an intercooler of an internal combustion engine that includes an outlet tank that collects the intake air that has passed through the passage and guides it to the engine, make sure that the resonance frequency of the air column vibration that occurs in each of the intake core flow paths does not match the natural frequency of the intake system. An intercooler for an internal combustion engine, characterized in that a passage length of each intake core passage is set. 2. Each of the intake core flow paths is defined inside a flat tube having a corrugated plate-like inner fin, and the end of the inner fin is connected to the open end of the tube. The intercooler for an internal combustion engine according to claim 1, wherein the intercooler is arranged inside the interior with a predetermined offset amount L. 3. An inlet tank into which intake air pressure-fed from a supercharger is introduced, a plurality of intake core flow passages that allow the intake air introduced into the inlet tank to pass therethrough to radiate heat to a cooling medium, and each intake core. In an intercooler of an internal combustion engine including: an outlet tank that collects intake air that has passed through the flow path and guides it to the engine, the resonance frequencies of air column vibrations that occur in the intake core flow paths are different from each other. Intercooler for internal combustion engine. 4. The intake core flow passages are defined by a plurality of flat tubular tubes through a plurality of corrugated inner fins, and the length of each inner fin in the intake core flow passage direction is defined. 4. The intercooler for an internal combustion engine according to claim 3, wherein the intercoolers are different from each other. 5. The length of each intake core passage in the intake core passage direction is defined by a plurality of flat tubular tubes through a plurality of corrugated inner fins. 4. The intercooler for an internal combustion engine according to claim 3, wherein the intercoolers are different from each other.