JP2004316611A - Cooling device for exhaust gas from engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device for exhaust gas from an engine capable of obtaining desired muffling effect by promoting the heat exchange rate of an exhaust cooler. <P>SOLUTION: An exhaust cooler 1 comprising a cylindrical outer cylinder 1a with both ends closed, a plurality of small exhaust pipes 1b penetrating both closed ends of the outer cylinder 1a and protruding from both sides, a cooling water passage 1f formed around the small exhaust pipes 1b, an introduction port 1c and a discharge port 1d fixed while penetrating a side surface of the outer cylinder 1a with one end thereof facing the cooling water passage 1f is interposed in the middle of an exhaust passage to constitute parallel passages 4 comprising a first passage 4a via the small exhaust pipe 1b and a second passage 4b outside the exhaust cooler 1, a control valve 5 to open/close at least one passage of the parallel passages 4 is provided, and the exhaust cooler 1 is cooled by allowing traveling air of a vehicle to be blown thereagainst. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an engine exhaust cooling device that more effectively enhances the silencing effect of an exhaust silencer provided in an exhaust passage of an engine.
[0002]
[Prior art]
Conventionally, an exhaust cooling device is disposed upstream of an exhaust muffler provided in an exhaust passage, and cooling water is circulated through the exhaust cooling device to lower the exhaust temperature. The technology of an engine exhaust silencer for reducing engine noise is known (see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2002-70528 (Pages 1-3, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in the conventional invention, cooling water is circulated through the swirl tube group, and the swirl tube group is exposed to exhaust gas so as to take heat of the exhaust gas and exchange heat. The temperature of the spiral tube group itself as a cooler or the whole apparatus becomes high, and as a result, there is a problem that the exhaust gas is not sufficiently cooled and a desired noise reduction effect cannot be obtained.
[0005]
The present invention has been made in view of the above problems, and has an object of promoting a heat exchange rate of an exhaust cooler by applying a traveling wind of a vehicle to an exhaust cooler to cool the air. An object of the present invention is to provide an exhaust gas cooling device for an engine capable of obtaining a noise reduction effect.
[0006]
Further, in the exhaust gas cooling device for an engine of the present invention, it is an object to achieve an efficient heat exchange and a silencing effect of exhaust gas when an exhaust cooler is installed in a muffler.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, in an exhaust gas cooling device for an engine provided in an exhaust passage from an engine to cool exhaust gas, an exhaust cylinder having both ends closed and a cylindrical outer cylinder penetrating both closed ends of the outer cylinder. A plurality of small exhaust pipes protruding to both sides, a cooling water passage formed around the plurality of small exhaust pipes, and fixed through the side surface of the outer cylinder with one end facing the cooling water passage. An exhaust cooler having an introduction port and an exhaust port, which are provided in the middle of the exhaust passage, a first passage passing through a plurality of small exhaust pipes of the exhaust cooler, and a second passage outside the exhaust cooler. And a control valve that opens and closes at least one of the parallel passages is provided, and the exhaust cooler is air-cooled by applying a traveling wind of a vehicle to the exhaust cooler.
[0008]
According to a second aspect of the present invention, in the exhaust cooling system for an engine according to the first aspect, the exhaust cooler is covered with an insulator having a ventilation hole.
[0009]
According to a third aspect of the present invention, in the engine exhaust cooling device of the second aspect, a wind guide plate is provided on the insulator.
[0010]
According to a fourth aspect of the present invention, there is provided an exhaust gas cooling device for an engine provided in an exhaust passage from an engine to cool exhaust gas, wherein the cylindrical outer cylinder is closed at both ends, and both closed ends of the outer cylinder are penetrated. A plurality of small exhaust pipes protruding to both sides, a cooling water passage formed around the plurality of small exhaust pipes, and fixed through the side surface of the outer cylinder with one end facing the cooling water passage. An exhaust cooler having an introduction port and an exhaust port, which is provided in the middle of an exhaust passage in the muffler, a first passage passing through a plurality of small exhaust pipes of the exhaust cooler, and a first external passage outside the exhaust cooler. A parallel passage composed of two passages is provided, and a control valve for opening and closing at least one of the parallel passages is provided, and the exhaust air cooler is air-cooled by introducing a traveling wind of the vehicle into the muffler. .
[0011]
According to a fifth aspect of the present invention, in the exhaust cooling system for an engine according to the fourth aspect, a ventilation hole is provided in a shell of the muffler, and the exhaust air cooler is air-cooled by introducing a traveling wind of the vehicle from the ventilation hole. And
[0012]
Function and effect of the present invention
According to the first aspect of the present invention, the exhaust cooler is interposed in the middle of the exhaust passage, and is connected to the first passage passing through the plurality of small exhaust pipes of the exhaust cooler and the second passage outside the exhaust cooler. And a control valve for opening and closing at least one of the parallel passages.
[0013]
Then, the exhaust cooler is air-cooled by being exposed to the traveling wind of the vehicle.
[0014]
Therefore, the exhaust cooler can improve the heat exchange rate by avoiding a temperature rise due to the exhaust gas, and as a result, can obtain a desired noise reduction effect.
[0015]
In addition, an increase in ambient temperature due to heat conduction of the exhaust cooler can be suppressed.
[0016]
Furthermore, by performing air cooling with the traveling wind of the vehicle, it is possible to cool the exhaust cooler without requiring a complicated device or extra cost, and without imposing a load on the exhaust cooler or the engine cooling system.
[0017]
Also, as compared with the conventional invention, at least one of the parallel passages is opened and closed by an exhaust control valve in accordance with the state of the engine and the like, and the flow rate of exhaust flowing through the exhaust cooler is controlled. Is suppressed, the radiator can be prevented from increasing in size, and a desired noise reduction effect by exhaust cooling can be obtained.
[0018]
According to the second aspect of the present invention, since the exhaust cooler is covered with the insulator having the ventilation hole, the exhaust air cooler can be air-cooled by introducing the traveling wind of the vehicle from the ventilation hole, and the periphery of the exhaust cooler can be cooled by the insulator. Can prevent heat damage.
[0019]
According to the third aspect of the present invention, since the air guide plate is provided on the insulator, the exhaust air cooler can be efficiently guided by the traveling wind to the ventilation holes of the insulator.
[0020]
According to the fourth aspect of the present invention, the exhaust cooler is interposed in the exhaust passage of the muffler, the first passage passing through a plurality of small exhaust pipes of the exhaust cooler, and the second passage outside the exhaust cooler. And a control valve for opening and closing at least one of the parallel passages.
[0021]
And since the exhaust air cooler is air-cooled by introducing the wind of the vehicle into the muffler, the heat exchange rate of the exhaust cooler can be greatly increased, and the exhaust temperature inside the muffler is reduced to reduce the volume, An excellent noise reduction effect can be obtained.
[0022]
Furthermore, the effect of reducing and expanding the exhaust gas passing through the small exhaust pipe is obtained, and the effect of reducing the muffler discharge noise is obtained.
[0023]
According to the fifth aspect of the present invention, since the exhaust air cooler is air-cooled by introducing the traveling wind of the vehicle from the ventilation hole of the muffler shell, the traveling wind of the vehicle can be reduced without the need for complicated devices or extra costs. It can be introduced inside to cool the exhaust cooler.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an exhaust gas cooling device for an engine of the present invention will be described.
[0025]
<Embodiment 1>
Hereinafter, Embodiment 1 of the present invention will be described.
[0026]
FIG. 1 is a side sectional view of an exhaust gas cooling device for an engine of the present invention, FIG. 2 is a sectional view taken along line S2-S2 of FIG. 1, and FIG. 3 is an operation explanatory diagram showing a state where an exhaust control valve is opened and closed.
[0027]
First, the overall configuration will be described.
[0028]
As shown in FIGS. 1 and 2, in the exhaust cooling system for an engine according to the present embodiment, an exhaust cooler 1 penetrates a cylindrical outer cylinder 1 a having both ends closed and both closed ends of the outer cylinder 1 a. And a plurality of small exhaust pipes 1b protruding to both sides, and an inlet port 1c and a discharge port 1d formed of a double pipe fixedly penetrating through one side and the other side of the outer cylinder 1a. I have.
[0029]
The exhaust cooler 1 configured as described above cuts off the middle of the exhaust pipe 2 constituting the exhaust passage of the engine, and fits and fixes each end of the split exhaust pipe 2 to the outer circumference of both ends of the outer cylinder 1a. A first passage 4a is formed as one of the parallel passages 4 passing through the small exhaust pipe 1b in the exhaust cooler 1, and between the plurality of small exhaust pipes 1b inside the outer cylinder 1a from the introduction port 1c to the discharge port 1d. A cooling water passage 1f is formed.
[0030]
Thus, an exhaust cooling water circuit is introduced into the exhaust cooler 1 from the engine cooling water circuit (not shown) by the introduction port 1c and returns to the engine cooling water circuit from the discharge port 1d.
[0031]
At both ends of the exhaust pipe 2, a bypass pipe 3 fixed so as to surround a part of the outer circumference of the exhaust pipe 2 is connected and fixed.
[0032]
A plurality of small holes 2a and 2b are respectively formed in the outer peripheral surfaces on the upstream side and the downstream side of the exhaust pipe 2, and the small holes on the downstream side pass through the exhaust passage of the bypass pipe 3 from the upstream small hole 2a. A second passage 4b is formed as the other of the parallel passages 4 extending from 2b to the exhaust pipe 2 on the downstream side again.
[0033]
The total cross-sectional area of the small holes 2a (2b), which is the minimum passage of the second passage 4b, is set to be equal to or larger than the cross-sectional area of the exhaust pipe 2 on the upstream side.
[0034]
An exhaust control valve (control valve) 5 for opening and closing the second passage 4b in the exhaust pipe 2 is provided downstream of the small hole 2a of the exhaust pipe 2 on the upstream side.
[0035]
Further, below the exhaust cooler 1, an insulator 10 fixed to a part of the outer periphery of the bypass pipe 3 is provided so as to cover the lower part of the exhaust cooler 1, and a plurality of ventilation A hole 11 and a baffle plate 12 are provided.
[0036]
Hereinafter, the operation and effect of the engine exhaust cooling device of the present invention will be described.
[0037]
The exhaust cooler 1 configured as described above closes the exhaust control valve 5 when the engine is running at a low speed, and transfers the entire amount of exhaust gas to the first exhaust passage 4a into the small exhaust pipe 1b of the exhaust cooler 1 as shown in FIG. Since the exhaust gas flows downstream through the small exhaust pipe 1b, the exhaust gas exchanges heat with the cooling water when passing through the small exhaust pipe 1b and is cooled to reduce the volume, thereby reducing the exhaust noise when being discharged to the atmosphere.
[0038]
Next, when the engine speed is high, the exhaust control valve 5 is driven to open the second passage 4b as shown in FIG.
[0039]
In this case, a part of the exhaust gas passes through the second passage 4b from the small hole 2a, so that the exhaust gas can be released to the atmosphere without increasing the pressure loss while performing heat exchange with the exhaust cooler 1, thereby increasing the pressure. The burden on the radiator can be reduced, and the size of the radiator can be avoided.
The opening of the exhaust control valve 5 is continuously adjusted according to the engine speed.
[0041]
Further, since the total area of the small holes 2a (2b) is set to be equal to or larger than the cross-sectional area of the exhaust pipe 2, the exhaust pressure is prevented from rising even at high engine speed where the exhaust flow rate is large. Does not degrade performance.
[0042]
As described above, since the insulator 10 is provided below the exhaust cooler 1, heat damage to the outside due to heat conduction of the exhaust cooler 1 is prevented, and at the same time, through the ventilation holes 11 of the insulator 10. After the traveling wind of the vehicle (indicated by a dashed arrow) is introduced and the exhaust cooler 1 is air-cooled, the exhaust cooler 1 escapes to the outside again.
[0043]
At this time, the air guide plate 12 receives the traveling wind of the vehicle and guides the wind to the ventilation holes 11.
[0044]
Therefore, in the exhaust cooling device for an engine of the present embodiment, the traveling wind guided by the baffle plate 12 is introduced from the ventilation hole 11 to air-cool the exhaust cooler 1, thereby flowing through the first passage 4 a. The heat exchange efficiency can be improved by cooling the exhaust gas to be cooled by both water cooling and air cooling, and as a result, a desired noise reduction effect can be obtained.
[0045]
In addition, the insulator 10 can prevent a rise in ambient temperature due to heat conduction of the exhaust cooler 1.
[0046]
<Embodiment 2>
Hereinafter, Embodiment 2 of the present invention will be described.
[0047]
In the exhaust cooling system for an engine according to the present embodiment, the exhaust cooler 1 is the same as that of the above-described embodiment, and therefore, the same components are denoted by the same reference numerals, and description thereof is omitted.
[0048]
FIG. 4 is a side sectional view of a muffler to which the exhaust gas cooling device for an engine according to the present embodiment is applied, and FIG. 5 is an operation explanatory view showing a state in which an exhaust control valve is opened and closed.
[0049]
As shown in FIG. 4, in the exhaust gas cooling device for an engine according to the present embodiment, the inside of the shell 21 of the muffler 20 is formed by partition walls 22 and 23 so as to be separated into first to third chambers 24 to 26 in order from the upstream side. A first passage 40a is formed by disposing an exhaust pipe 27 from the engine side (not shown) across the first to third chambers 24 to 26c.
[0050]
Further, the exhaust pipe 27 is divided by the second chamber 25, and the exhaust cooler 1 is interposed here.
[0051]
Further, a small hole 20a is formed at a position corresponding to the first chamber 24 of the exhaust pipe 27, while a small hole 20b is formed at a position corresponding to the third chamber 26.
[0052]
A second passage 40b is formed above the exhaust pipe 27 by disposing a bypass pipe 30 communicating with the outside in the first to third chambers 24 to 26.
[0053]
An exhaust control valve 50 is provided at a position corresponding to the first chamber 24 of the bypass pipe 30, while a small hole 20 c is formed at a position corresponding to the third chamber 26.
[0054]
The total area of the small holes 20a and 20b and the total area of the small holes 20c are set to be equal to or larger than the sectional areas of the exhaust pipe 27 and the bypass pipe 30, respectively.
[0055]
Further, the shell 21 is provided with a plurality of ventilation holes 34 on the first passage 40a side and a plurality of ventilation holes 35 on the second passage 40b side.
[0056]
Hereinafter, the function and effect of the exhaust gas cooling device for an engine according to the present embodiment will be described.
[0057]
The exhaust cooler 1 configured as described above closes the exhaust control valve 50 when the engine is running at a low speed, and as shown in FIG. 5A, the entire amount of exhaust gas flows from the first passage 40a to the small exhaust pipe 1b of the exhaust cooler 1. After passing through the small exhaust pipe 1b, the exhaust gas is discharged to the atmosphere through the small holes 20c of the bypass pipe 30, so that the exhaust gas exchanges heat with the cooling water when passing through the small exhaust pipe 1b, and is cooled to reduce the volume. As a result, exhaust noise when emitted to the atmosphere is reduced.
[0058]
Next, when the engine rotates at a high speed, the exhaust control valve 50 is driven to open the second passage 40b as shown in FIG. 5B.
[0059]
In this case, since a part of the exhaust gas passes through the second passage 40b from the small hole 20a, the exhaust gas is released to the atmosphere while exchanging heat with the exhaust cooler 1 without increasing the pressure loss of the exhaust gas. The load on the radiator can be reduced, and the radiator can be prevented from becoming larger.
[0060]
The traveling wind of the vehicle (indicated by a broken line arrow) passes through the ventilation holes 34 of the shell 21 to the ventilation holes 35, whereby the traveling wind of the vehicle is introduced into the muffler 20, and the exhaust cooler 1 is air-cooled. You.
[0061]
At this time, the bypass pipe 30 is also air-cooled together with the exhaust cooler 1 by the traveling wind.
[0062]
Therefore, in the exhaust cooling system for an engine according to the present embodiment, the exhaust air cooler 1 and the bypass pipe 30 are both cooled by introducing the traveling wind of the vehicle into the muffler 20 so that the first passage 40a and the second A decrease in the volume of the exhaust gas in the passage 40b due to a decrease in the temperature of the exhaust gas can be promoted.
[0063]
Further, since the exhaust gas repeatedly shrinks and expands when passing through the small holes 20a to 20c, the effect of reducing the exhaust sound due to the shrinking / expanding effect is obtained.
[0064]
Therefore, as compared with the related art, it is possible to achieve both efficient heat exchange of the exhaust gas and a silencing effect when the exhaust cooler is installed in the muffler.
[0065]
The embodiment of the present invention has been described above. However, the specific configuration of the present invention is not limited to the present embodiment, and the present invention is applicable even if there is a design change without departing from the gist of the invention. include.
[0066]
For example, the shapes, the number of installations, and the installation positions of the air guide plate and the ventilation holes can be appropriately set.
[0067]
Also, the installation position and type of the exhaust control valve can be set as appropriate.
[0068]
Further, as shown in FIG. 6, it is naturally conceivable to form the cut-and-raised portion 50 in the ventilation hole to smoothly introduce the traveling wind.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an exhaust gas cooling device for an engine according to a first embodiment of the present invention.
FIG. 2 is a sectional view taken along line S2-S2 of FIG.
FIG. 3 is an operation explanatory view showing an open / closed state of the exhaust control valve according to the embodiment.
FIG. 4 is a side sectional view of a muffler to which an exhaust gas cooling device for an engine according to a second embodiment of the present invention is applied.
FIG. 5 is an operation explanatory view showing an open / closed state of the exhaust control valve of the present embodiment.
FIG. 6 is a diagram illustrating another example of a ventilation hole.
[Explanation of symbols]
Reference Signs List 1 exhaust cooler 1a outer cylinder 1b small exhaust pipe 1c introduction port 1d discharge port 1f cooling water passage 2 exhaust pipe 2a, 2b small hole 3 bypass pipe 4 parallel passage 4a first passage 4b second passage 5 exhaust control valve 10 insulator 11 ventilation Hole 12 Wind guide plate 20 Muffler 21 Shell 22, 23 Partition wall 24 First chamber 25 Second chamber 26 Third chamber 20a, 20b, 20c Small hole 30 Bypass pipe 34, 35 Vent hole 40a First passage 40b Second passage 50 Exhaust Control valve

Claims (5)

In an engine exhaust cooling device provided in an exhaust passage from an engine to cool exhaust gas,
A cylindrical outer cylinder with both ends closed,
A plurality of small exhaust pipes penetrating both closed ends of the outer cylinder and projecting to both sides;
A cooling water passage formed around the plurality of small exhaust pipes;
An introduction port and a discharge port fixedly penetrating the side surface of the outer cylinder with one end facing the cooling water passage;
An exhaust cooler provided with is provided in the middle of the exhaust passage,
A control valve is provided for forming a parallel passage including a first passage passing through a plurality of small exhaust pipes of the exhaust cooler and a second passage outside the exhaust cooler, and opening and closing at least one of the parallel passages. ,
An exhaust cooling system for an engine, wherein the exhaust cooler is air-cooled by applying a traveling wind of a vehicle. The exhaust gas cooling device for an engine according to claim 1,
An exhaust cooling device for an engine, wherein the exhaust cooler is covered with an insulator having a ventilation hole. The exhaust gas cooling device for an engine according to claim 2,
An exhaust cooling device for an engine, wherein a wind guide plate is provided on the insulator. In an engine exhaust cooling device provided in an exhaust passage from an engine to cool exhaust gas,
A cylindrical outer cylinder with both ends closed,
A plurality of small exhaust pipes penetrating both closed ends of the outer cylinder and projecting to both sides;
A cooling water passage formed around the plurality of small exhaust pipes;
An introduction port and a discharge port fixedly penetrating the side surface of the outer cylinder with one end facing the cooling water passage;
An exhaust cooler with is installed in the exhaust passage in the muffler,
A control valve for forming a parallel passage including a first passage passing through a plurality of small exhaust pipes of the exhaust cooler and a second passage outside the exhaust cooler, and providing at least one of the parallel passages with a control valve is provided. ,
An exhaust cooling system for an engine, wherein a running wind of a vehicle is introduced into the muffler to air-cool an exhaust cooler. The exhaust gas cooling device for an engine according to claim 4,
An exhaust cooling system for an engine, wherein a ventilation hole is provided in a shell of the muffler, and an exhaust cooler is air-cooled by introducing a traveling wind of a vehicle from the ventilation hole.

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