JP2000130276A - Exhaust gas introducing device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas introducing device of an internal combustion engine capable preventing the thermal effect to an intake manifold, by sufficiently lowering the temperature of exhaust gas to be introduced from an exhaust gas recirculation passage of an EGR device into intake air. SOLUTION: In an exhaust gas introducing device 8, exhaust gas from an exhaust gas circulation passage is introduced from an inflow port 40 to an annular exhaust passage 36 in a wall part 34 of a cylindrical member 30, and the exhaust gas is discharged from an introducing port 38 into an intake passage 32 while circumferentially flowing in the exhaust passage 36. Since the exhaust passage 36 is formed into an annular shape, the front surface area is very wide. In theory, the exhaust passage 36 having the infinite length is circumferentially formed in the wall part 34 of the cylindrical member 30, and therefore, the heat of exhaust gas is sufficiently absorbed by the inner surface of the wall part 34. Since sufficiently cooled exhaust gas is introduced from the introducing port 38 into intake air, a downstream intake manifold 16 can be prevented from being thermally affected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas introduction device for an internal combustion engine that introduces exhaust gas from an exhaust gas recirculation path into intake air.

[0002]

2. Description of the Related Art An exhaust gas recirculation device (hereinafter, referred to as an EGR device) for guiding exhaust gas into intake air to reduce nitrogen oxides in exhaust gas of an internal combustion engine is known. This EGR
In the device, the exhaust is usually returned between the throttle body and the intake manifold to mix with the intake.

In recent years, studies have been made to form the intake manifold from a lightweight material such as a resin in order to reduce the weight of the internal combustion engine. However, when an EGR device is applied to such an intake manifold, since the exhaust gas is at a high temperature, if the intake manifold is formed of a material having low heat resistance such as a resin, the EGR device causes the exhaust gas to be located upstream of the intake manifold. The introduced high-temperature exhaust gas may come into contact with the inner surface of the intake manifold and cause thermal deterioration such as thermal deformation and melting of the intake manifold.

As a conventional technique for preventing this thermal deterioration, Japanese Patent Laid-Open Publication No. Hei 10-47170 discloses a technique in which cooling water is introduced into a cylindrical member for introducing exhaust gas to cool exhaust gas passing through the cylindrical member. Thus, the thermal influence on the intake manifold is reduced.

[0005]

However, in the above-mentioned prior art, since the exhaust path formed in the cylindrical member is the minimum necessary, the distance over which the exhaust flows in the cylindrical member is extremely short. Even if the cylindrical member is cooled, the exhaust gas flows out to the intake manifold as it exits the intake passage without being sufficiently cooled. For this reason, the temperature of the intake manifold may be increased by the heat of the exhaust gas, and the thermal effect on the intake manifold has not yet been eliminated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust gas introducing device for an internal combustion engine capable of sufficiently reducing the temperature of exhaust gas introduced into intake air from an exhaust gas recirculation path, thereby preventing thermal influence on an intake manifold. Things.

[0007]

According to a first aspect of the present invention, there is provided an exhaust gas introduction device for an internal combustion engine for introducing exhaust gas into an intake air from an exhaust gas recirculation passage, wherein the exhaust gas is introduced between a throttle body and an intake manifold. A tubular member interposed therebetween and guiding intake air from the throttle body side to the intake manifold side by an intake passage formed therein; and the intake passage in a wall of the tubular member surrounding the intake passage. An exhaust passage formed in an annular shape in the circumferential direction of the exhaust gas recirculation passage, and an inflow port provided in the cylindrical member for allowing the exhaust gas from the exhaust recirculation passage to flow into the exhaust passage. And an introduction port provided in the cylindrical member to introduce exhaust gas flowing in the exhaust flow path into the intake passage.

In the present exhaust gas introducing device, the exhaust gas from the exhaust gas recirculation path is first introduced from the inflow port into the annular exhaust flow path in the wall of the cylindrical member. The exhaust gas that enters the annular exhaust flow path
While flowing through the exhaust passage, the air exits from the inlet into the intake passage. Since the exhaust passage is formed in an annular shape, the exhaust surface has an extremely large surface area, and theoretically an infinitely long exhaust passage is formed in the wall of the cylindrical member. , Heat is sufficiently absorbed. Since the exhaust gas thus sufficiently cooled is introduced into the intake air from the inlet, it is possible to prevent the downstream intake manifold from being thermally affected.

According to a second aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, the wall portion is cooled by air or water. By cooling the wall of the tubular member by air cooling or water cooling, much heat can be taken from the exhaust gas. In particular, by cooling with water, more heat can be taken from the exhaust gas. Thus, the temperature of the exhaust gas introduced into the intake air can be sufficiently reduced, and the thermal effect on the intake manifold can be further reduced.

According to a third aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine according to the first or second aspect, the introduction port is annularly formed in an inner peripheral surface of the wall in a circumferential direction of the intake passage. And the exhaust guide direction is substantially the intake flow direction.

As described above, since the shape of the inlet for introducing the gas into the intake passage from the annular exhaust passage in the wall of the cylindrical member is annular, and since the exhaust guide direction is the intake flow direction, the shape of the inlet is different from that of the inlet. The exhaust blown out to the intake passage is sent to the intake manifold side so as to surround the intake air flowing from the throttle body side.

As a result, the exhaust gas having a sufficient flow velocity vigorously flows on the inner wall surface side of the intake passage, and the intake air is enveloped in the center of the vigorously flowing exhaust gas. For this reason, the flow velocity of the entire intake air should be increased against the wall resistance of the intake passage as compared with a case where the intake air is simply flowing or a case where the exhaust gas simply flows perpendicular to the intake air flow as in the related art. Can be. Therefore, the volume efficiency of the internal combustion engine can be improved.

According to a fourth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine according to any one of the first to third aspects, the exhaust guiding direction of the inlet is substantially tangential to the annular exhaust flow path. It is characterized by being formed so that it becomes.

As described above, by making the direction of exhaust gas flowing into the annular exhaust flow path substantially tangential to the exhaust flow path, the exhaust gas can flow at high speed in the circumferential direction in the exhaust flow path. This makes it possible to eliminate exhaust gas stagnation in the exhaust flow path and to spread the exhaust gas throughout the exhaust flow path, so that sufficiently cooled exhaust gas can be introduced into the intake passage from the inlet.

According to a fifth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, the exhaust gas passage extends substantially in the axial direction of the tubular member. A spiral exhaust guide fin having a direction as an axis is formed.

Since such a spiral exhaust guide fin is formed in the exhaust passage, the exhaust can be guided and smoothly flow in the circumferential direction in the exhaust passage. It is possible to eliminate the stagnation of the exhaust gas in the inside and to spread the exhaust gas throughout the exhaust passage. In addition, since all the exhaust is moved along the exhaust guide fins, the cooling distance is forcibly extended. As a result, the exhaust gas sufficiently cooled can be introduced into the intake passage from the inlet.

According to a sixth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine according to any one of the first to fifth aspects, the wall portion includes an inner wall portion disposed inside the exhaust passage. And an outer wall portion disposed outside the exhaust passage.

By providing the inner wall portion and the outer wall portion as the wall portion of the tubular member in this manner, it is easy to form an exhaust passage in the wall portion in the circumferential direction of the intake passage. According to a seventh aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine according to the sixth aspect, a cooling fin is formed on an outer peripheral surface of the outer wall portion.

Since the cooling fins are formed on the outer peripheral surface as described above, the heat radiation area is increased, and the exhaust gas can be cooled more efficiently. According to an eighth aspect of the present invention, there is provided the exhaust gas introduction device for an internal combustion engine according to the sixth or seventh aspect, wherein a throttle body and an intake manifold are connected by the outer wall.

Since the throttle body and the intake manifold are connected by the outer wall as described above, the exhaust passage and the inlet can be easily formed.

According to a ninth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, the outer wall portion is deformable with respect to the configuration of the eighth aspect. If the outer wall portion connects the throttle body and the intake manifold and the outer wall portion is deformable, the vibration of the internal combustion engine from the intake manifold side is difficult to be transmitted to the throttle body side, thereby preventing vibration. Produces an effect.

According to a tenth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, the outer wall portion is formed in a bellows-like configuration in the ninth aspect. By forming the outer wall portion in a bellows shape, the outer wall portion can be flexibly deformed against vibration. For this reason, a high vibration prevention effect is produced.

According to an eleventh aspect of the present invention, there is provided the exhaust gas introduction device for an internal combustion engine, wherein a deposit caused by exhaust gas flowing backward in the intake passage upstream of the intake port is prevented. A deposit blocking portion is provided.

By providing the deposit blocking portion as described above, the intake air may flow backward depending on the type and operating state of the internal combustion engine, and the exhaust gas may flow upstream from the inlet to deposit deposits on the throttle body. The deposit component in the exhaust gas can be preferentially deposited at the deposit blocking portion. For this reason, deposit accumulation on the throttle body side can be suppressed.

According to a twelfth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine according to the eleventh aspect of the present invention, the deposit blocking portion is provided for a gasket disposed between the throttle body and the tubular member. It is characterized by being formed integrally.

By forming the deposit blocking portion as a part of the gasket, the number of parts is not increased, the manufacturing process can be simplified, and the manufacturing cost can be suppressed.

[0027]

[First Embodiment] FIG. 1 is a schematic structural view of a four-cylinder gasoline engine for driving a vehicle, incorporating an exhaust gas introducing device to which the above-described invention is applied. Here, the intake air (indicated by a dotted white arrow in the drawing) taken in from an air cleaner (not shown) is supplied to the intake pipe 2.
And is introduced into the throttle body 4.
In the throttle body 4, after the amount of intake air is adjusted by an internal throttle valve 6, the intake air flows into the exhaust introduction device 8.

Exhaust gas is introduced into the intake gas from the exhaust manifold 14 through the exhaust gas recirculation path 12 into the intake air in accordance with the operation state of the engine 10. Then, the intake air flows from the exhaust introduction device 8 into the intake manifold 16, and the engine 1
0 is introduced into each of the cylinders 10a, 10b, 10c, 10d.

In each of the cylinders 10a to 10d, a fuel injection valve (not shown) directly feeds the cylinders 10a to 1d.
A fuel-air mixture is formed by injecting fuel into 0d, and then the fuel-air mixture is ignited by a spark plug (not shown), thereby generating a rotational torque in the engine 10 and serving as a driving force for the vehicle.

The exhaust gas after combustion is supplied to each of the cylinders 10a to 10d.
Are discharged from the exhaust manifold 14 as indicated by a dotted black arrow, collected in the exhaust manifold 14, and discharged to the outside via a three-way catalyst, a muffler, and the like (not shown). A part of the exhaust gas is returned to the exhaust gas introducing device 8 through the exhaust gas recirculation path 12 as necessary, as described above.

An exhaust gas recirculation valve (hereinafter, referred to as an EGR valve) 20 is disposed in the exhaust gas recirculation path 12. The opening degree of the EGR valve 20 is determined by an electronic control unit (hereinafter referred to as ECU) 22 which detects the operating state of the engine 10 using various sensors (not shown). (The ratio of exhaust gas during intake).

A part 12a of the exhaust gas recirculation path 12 also serves as a part of an intake detour circuit 24 that bypasses the throttle valve 6 for idle speed control. Idle speed control valve 2
When the engine 10 is in an idle state, the opening thereof is adjusted by the ECU 22 to control the number of revolutions of the engine 10 during idling.

The throttle body 4 and the exhaust gas introducing device 8 are made of metal (for example, aluminum or aluminum alloy is mainly used), and the intake manifold 16 is mainly made of resin. A metal gasket 5 is disposed between the flange 4a of the throttle body 4 and the upstream flange 7a of the exhaust gas introducing device 8, and the downstream flange 7b of the exhaust gas introducing device 8 and the flange 16a of the intake manifold 16 are arranged. The heat insulating packing 9 is disposed between the two.

Next, a detailed configuration of the exhaust gas introducing device 8 will be described. FIG. 2 shows a sectional configuration diagram of the exhaust gas introducing device 8. The exhaust gas introducing device 8 has a tubular member 30 that constitutes substantially the entirety. An intake passage 32 is formed at the center of the cylindrical member 30 and guides intake air from the throttle body 4 to flow toward the intake manifold 16.

In a wall portion 34 surrounding the intake passage 32,
Exhaust flow path 36 formed annularly in the circumferential direction of intake passage 32
Are formed. On the downstream side of the exhaust passage 36, an annular inlet 38 that is continuously open over the entire circumference of the intake passage 32 is formed. An inlet 40 is formed on the upstream side of the exhaust passage 36. A part 12a of the exhaust gas recirculation path 12 is connected to the inflow port 40 via a pipe member 8a provided on the outer peripheral surface of the tubular member 30. As a result, the exhaust gas from the exhaust gas recirculation path 12
From the exhaust passage 36.

Since the exhaust gas introducing device 8 is configured as described above, the ECU 22 is operated while the engine 10 is operating.
When the EGR valve 20 is opened by the control described above, a part of the exhaust gas of the engine 10 discharged to the exhaust manifold 14 flows into the exhaust flow path 36 from the inflow port 40 through the exhaust gas recirculation path 12. Since the exhaust passage 36 has an annular shape, the exhaust gas flows in the circumferential direction so as to wrap around the entire cylindrical member 30, flows in the exhaust passage 36, and finally, the entirety of the annular inlet 38. , Flows into the intake passage 32.

At this time, the downstream end portion 36 of the exhaust passage 36
a is formed in a direction that forms an acute angle with the inner peripheral surface of the intake passage 32 toward the downstream direction of the intake air. This allows
The exhaust guide direction by the downstream end portion 36a is substantially the flow direction of the intake air flowing through the intake passage 32.

Further, since the inlet 38 surrounds the entire circumference of the intake passage 32 in an annular shape, the exhaust gas flowing out of the inlet 38 into the intake passage 32 is centered on the intake air flowing from the throttle body 4 side. The air flows along the inner peripheral surface of the intake passage 32 so as to surround the intake air.

According to the first embodiment described above, the following effects can be obtained. (I). In the present exhaust gas introducing device 8, the exhaust gas from the exhaust gas recirculation path 12 is introduced from the inflow port 40 into the annular exhaust flow path 36 in the wall 34 of the tubular member 30. Annular exhaust passage 3
The exhaust gas that has entered 6 flows out of the inlet 38 into the intake passage 32 while flowing in the exhaust passage 36 in the circumferential direction. Since the exhaust passage 36 is formed in an annular shape, the exhaust passage 36 has a very large surface area, and theoretically, the exhaust passage 36 having an infinite length in the circumferential direction is formed in the wall portion 34 of the tubular member 30. As a result, the exhaust gas is sufficiently absorbed by the inner surface of the wall portion 34. Then, since the exhaust gas sufficiently cooled is introduced into the intake air from the inlet 38, it is possible to prevent the downstream intake manifold 16 from being thermally affected.

(B). Since the shape of the inlet 38 introduced from the annular exhaust passage 36 in the wall 34 of the cylindrical member 30 into the intake passage 32 is annular, and the exhaust guide direction is substantially the intake air flow direction, the inlet The exhaust gas blown out from 38 into the intake passage 32 is sent out to the intake manifold 16 side so as to surround the intake air flowing from the throttle body 4. As a result, exhaust gas having a sufficient flow velocity flows vigorously on the inner wall surface of the intake passage 32 as assist air, and the intake air is wrapped around the center of the vigorously flowing exhaust gas. Therefore, as shown in the flow velocity distribution in FIG. 3, the velocity of the intake air flowing from the exhaust introduction device 8 to the intake manifold 16 also increases at the inner wall portion of the intake passage 32, and the overall velocity of the intake air is high. Therefore, the flow velocity can be increased against the wall resistance of the intake passage 32 as compared with a case where the intake air is simply flowing or a case where the exhaust gas simply flows orthogonally to the intake flow as in the related art. Engine 1
0 can improve the volumetric efficiency.

(C). The portion of the wall portion 34 of the tubular member 30 downstream of the inlet 38 is made of a metal having a sufficient mass in a solid state because the exhaust passage 36 does not exist. Therefore, the amount of heat can be more quickly removed from the exhaust gas introduced into the intake passage 32 from the inlet port 38, and the temperature of the intake air flowing toward the intake manifold 16 can be further reduced.

[Second Embodiment] FIG. 4 is a sectional view showing an exhaust gas introduction device 108 according to a second embodiment. This exhaust introduction device 1
08 differs from Embodiment 1 in that the cylindrical member 130
Is provided with cooling fins 130a on the outer peripheral surface of the fin. In addition, the wall part 1 downstream from the vicinity of the inlet 138
Although 34a is thinner than in the first embodiment, it may be formed as thick as in the first embodiment. Other configurations are the same as those of the first embodiment.

According to the second embodiment described above, the following effects can be obtained. (I). The same effects as (a) and (b) of the first embodiment can be obtained. (B). Since the cooling fins 130a are provided on the outer peripheral surface of the cylindrical member 130 on the outer peripheral surface of the cylindrical member 130, the wall portion 134 is cooled by air cooling. As a result, a large amount of heat can be removed from the exhaust gas flowing from the inflow port 140 and flowing in the exhaust passage 136 in the circumferential direction through the wall portion 134. In this way, the temperature of the exhaust gas introduced into the intake air flowing through the intake passage 132 can be reduced, and the thermal effect on the intake manifold 16 can be further reduced.

[Embodiment 3] FIG. 5 is a sectional view showing an exhaust gas introduction device 208 according to Embodiment 3. Also, AA in FIG.
FIG. 6 shows a sectional view. This exhaust gas introduction device 208 differs from the first embodiment in that the wall of the cylindrical member 230 is formed of three metal cylindrical members 234a, 234b, and 234c. The first cylindrical member 234a has a small diameter except for the flange portion 235a. The upstream side of the second cylindrical member 234b has a large diameter, and the downstream side has the same small diameter as the first cylindrical member 234a. Second
The large-diameter portion of the cylindrical member 234b houses the first cylindrical member 234a inside. Except for the flange portion 235c, the third cylindrical member 234c is formed to have the same large diameter as the large diameter portion of the second cylindrical member 234b.
The small diameter portion of b is stored.

The three cylindrical members 234a, 234b, and 234c combined as described above are such that the upstream end of the second cylindrical member 234b is brazed to the flange portion 235a of the first cylindrical member 234a, and the third cylindrical member 234c Is brazed to the downstream end of the large diameter portion of the second cylindrical member 234b, and the downstream end of the small diameter portion of the second cylindrical member 234b is brazed to the flange 235c of the third cylindrical member 234c. I have. This allows the three cylindrical members 234
a, 234b, and 234c are integrated into the cylindrical member 23.
0 is formed.

The downstream end of the first cylindrical member 234a is not connected to the second cylindrical member 234b, and the gap forms the inlet 238. Also, the first cylindrical member 2
A gap is provided between 34a and the large diameter portion of the second cylindrical member 234b to form an exhaust passage 236. In the exhaust passage 236, the spiral exhaust guide fins 24 are provided.
4 are arranged.

The spiral exhaust guide fins 244
7, is formed by brazing a tape-shaped metal plate to the outer peripheral surface of the first cylindrical member 234a, and is formed in a spiral shape with the axial direction of the cylindrical member 230 as an axis. .

Further, a watertight space is formed between the small diameter portion of the second cylindrical member 234b and the third cylindrical member 234c to form a water cooling chamber 250. The water cooling room 250 is provided with a water pipe 250.
The cooling water of the engine 10 is distributed and recirculated by a and 250b.

Further, the difference from the first embodiment is that the pipe member 208a through which the exhaust gas flows from the part 12a of the exhaust gas recirculation path 12 is, as shown in FIG.
Is formed on a plane orthogonal to the axis of the first cylindrical member 234a and tangentially to the peripheral surface. As a result, the inlet 240 is connected to the exhaust passage 236.
The momentum of the exhaust gas flowing from the pipe member 208a through the pipe becomes the circumferential speed inside the exhaust flow path 236 as it is, thereby producing a high-speed swirling flow of the exhaust gas.

The other structure is the same as that of the first embodiment. According to the third embodiment described above, the following effects can be obtained. (I). The same effects as (a) and (b) of the first embodiment can be obtained.

(B). Since the pipe member 208a is attached as described above, the direction of the exhaust gas flowing into the annular exhaust channel 236 can be made substantially tangential to the exhaust channel 236. As a result, the exhaust gas can be swirled in the circumferential direction at high speed in the exhaust flow channel 236, eliminating the stagnation of the exhaust gas in the exhaust flow channel 236, and allowing the sufficiently cooled exhaust gas to flow from the inlet 238. It can be introduced into the intake passage 232.

(C). Since the spiral exhaust guide fins 244 are formed in the exhaust flow passage 236 as described above, the exhaust can be guided and smoothly flow in the circumferential direction in the exhaust flow passage 236. Road 236
The stagnation of exhaust gas inside can be more effectively eliminated. In addition, since all the exhaust is moved along the exhaust guide fins 244, the cooling distance is forcibly extended. Therefore, exhaust gas that has been sufficiently cooled can be introduced from the inlet 238 into the intake passage 232.

(D). Further, the inner peripheral surface of the cylindrical member 230 on the downstream side of the inlet 238 is forcibly cooled by the water cooling chamber 250, so that the exhaust gas is cooled more strongly than in the case of air cooling. Further, since the intake manifold 16 side is cooled by the water cooling chamber 250, the adverse effect of the conduction heat on the adjacent intake manifold 16 side can be sufficiently prevented.

(E). Since the exhaust guide fins 244 are made of metal, the second
Since the heat of the exhaust gas can be discharged to the cylindrical member 234b side, the temperature of the exhaust gas can be reduced more quickly.

(F). The exhaust introduction device 208 includes (a)
(E), as described in (e), exhibits extremely high cooling performance. Therefore, instead of the heat insulating packing 9, an inexpensive ordinary O is provided between the tubular member 230 and the intake manifold 16.
A ring can be used, and manufacturing cost can be reduced.

[Embodiment 4] FIG. 8 is a sectional view showing an exhaust gas introduction device 308 according to Embodiment 4. This exhaust introduction device 3
08 differs from Embodiment 1 in that the cylindrical member 330
Is composed of three metal wall portions 334a, 334b, 334c. Of these, the inner wall portion 334a has a small diameter except for the flange portion 335a. Auxiliary wall 3
34b, the upstream side has a large diameter, and the downstream side has an inner wall portion 33.
It is formed in the same small diameter as 4a. The large-diameter portion of the auxiliary wall portion 334b accommodates a part of the inner wall portion 334a on the downstream side. The outer wall portion 334c is formed in a bellows shape, and covers both the inner wall portion 334a and the auxiliary wall portion 334b. Ring-shaped flange portions 335b and 335c are brazed to both ends of the outer wall portion 334c, respectively.

In the three wall portions 334a, 334b, and 334c combined as described above, the flange portion 335b at the upstream end of the outer wall portion 334c is brazed to the flange portion 335a of the inner wall portion 334a. Further, the upstream end of the auxiliary wall portion 334b is brazed to the inside of the outer wall portion 334c. As a result, the three walls 334a, 334
b and 334c are integrated to form the wall of the tubular member 330.

The downstream end of the inner wall portion 334a is not connected to the auxiliary wall portion 334b, and the gap is
38 are formed. The inner wall 334a and the outer wall 3
34c, and between the inner wall portion 334a and the auxiliary wall portion 334.
A gap is provided between the large-diameter portion b and the exhaust passage 33.
6 are formed.

A pipe member 308a is connected to the outer wall portion 334c, and the exhaust gas recirculation path 1 is connected through the pipe member 308a.
Exhaust gas is introduced into the exhaust passage 336 from a part 12a of the second part 2a. Therefore, the exhaust gas flowing from the pipe member 308a flows through the exhaust flow path 336 and flows from the inlet 338 to the intake passage 3.
32.

The other structure is the same as that of the first embodiment. According to the fourth embodiment described above, the following effects can be obtained. (I). The same effects as (a) and (b) of the first embodiment can be obtained.

(B). The wall 334a of the cylindrical member 330,
In 334b and 334c, the outermost outer wall 334c is formed of a bellows-shaped metal plate. For this reason, the heat radiation area to the outside world is large and the cooling capacity is high. Thus, sufficiently cooled exhaust gas can be introduced from the inlet 338 into the intake passage 332.

(C). In the exhaust gas introduction device 308, only the outer wall portion 334c connects the throttle body 4 and the intake manifold 16. The outer wall portion 334c has a bellows shape and is not rigid but deformable, so that a floating structure is formed. Therefore, it is difficult to transmit the vibration of the engine 10 to the outside, and it is possible to produce an anti-vibration effect.

[Fifth Embodiment] FIG. 9 is a sectional view showing an exhaust gas introduction device 408 according to a fifth embodiment. This exhaust introduction device 4
08 is different from the fourth embodiment in that the flange portion 435a of the inner wall portion 434a and the flange portion 4a of the throttle body 4
Are different in the shape of the metal gasket 405 disposed therebetween. Other configurations are the same as those of the fourth embodiment.

As shown in FIG. 10, the metal gasket 405 includes a ring-shaped gasket portion 405a and a deposit blocking portion 4 arranged in a ring shape around the center hole of the gasket portion 405a.
05b. The gasket portion 405a is sandwiched between the flange portion 4a of the throttle body 4 and the flange portion 435a of the inner wall portion 434a, and the deposit blocking portion 405b protrudes from the inner peripheral surface of the intake passage 432.

The deposit blocking portion 405b is a metal net such as a punching metal and is made of a member having a large surface area. According to the fifth embodiment described above, the following effects can be obtained.

(A). Fourth Embodiment (A)-
The same effect as (c) is obtained. (B). Depending on the type and operating state of the engine 10, the intake air may flow backward in the intake passage 432. In such a case, the exhaust gas introduced into the intake passage 432 from the inlet 438 may reach the throttle body 4 side. If the exhaust gas reaches the respective parts of the throttle body 4 directly, deposits may occur, and it may be difficult for the ECU 22 to control the opening degree of the throttle valve 6 with the configuration shown in FIG.

In the fifth embodiment, the exhaust gas flowing backward from the inlet 438 along the inner peripheral surface of the intake passage 432 once passes through the deposit blocking portion 405b. During this passage, the deposit component in the exhaust gas becomes
Attaches to 5b. For this reason, adhesion of the deposit to the throttle valve 6 is suppressed, and the opening control operation of the throttle valve 6 can be maintained normally.

It should be noted that the deposit blocking portion 405b is only in the vicinity of the intake passage 432, and has a net shape, so that it has little effect on the intake efficiency. (C). The deposit blocking portion 405b is formed integrally with the gasket portion 405a. The deposit prevention portion 405b can be easily manufactured by punching the periphery of the center hole of the ring-shaped metal plate into a net shape, and the number of components is not increased, and the manufacturing process can be simplified, so that the manufacturing cost can be suppressed.

[Other Embodiments] In the first to fifth embodiments, an example of a gasoline engine has been described, but a diesel engine can be similarly applied.

In the second embodiment, instead of air cooling, a water cooling chamber may be provided as shown in the third embodiment to perform water cooling. In the third embodiment, the spiral exhaust guide fins 244 are fixed to the outer peripheral surface of the first cylindrical member 234a by brazing, but may be fixed to the inner peripheral surface of the second cylindrical member 234b. By doing so, the exhaust guide fins 2
The heat conduction from 44 to the second cylindrical member 234b is performed quickly, and the temperature of the exhaust gas can be reduced more quickly. Further, the spiral exhaust guide fins 244 are fixed in a state where they are tilted to the downstream side, but may be formed in a state where they are tilted to the upstream side. Further, the exhaust guide fins 244 have a spiral state in the same direction as the right-hand thread, but may have a spiral state in the same direction as the left-hand thread.

In the third embodiment, the spiral exhaust guide fins 244 are not used, and the pipe member 208a
May be set to be substantially tangential to the exhaust flow path 236. Conversely, the pipe member 208a may be attached in the same manner as in the first and second embodiments, and only the spiral exhaust guide fin 244 may be used.

In the first to fifth embodiments, the part 12a of the exhaust gas recirculation path 12 is provided with the intake bypass circuit 2 for idle speed control that bypasses the throttle valve 6.
4 also serves as a part, but the exhaust gas recirculation path may be formed independently. Incidentally, in order to improve the output torque of the engine 10 when the throttle valve 6 is fully opened, the idle speed control valve 26 may be opened so that the intake air is blown out from the inlet as assist air at a high speed to increase the volumetric efficiency. .

In the first to fifth embodiments, the inlets are all formed in a continuous annular shape. However, the partial circumferential inlets and the spot-like inlets are annularly arranged in the circumferential direction of the intake passage. May be done.

The engine 1 is opened when the EGR valve 20 is opened.
0 when the engine is rotating at medium load and the throttle valve 6
When the valve is fully opened, the EGR valve 20 is closed. However, as described in each of the first to fifth embodiments, the exhaust gas blown out from the inlet into the intake passage serves as assist air to increase the speed of intake air to increase volumetric efficiency. The control for opening the EGR valve 20 may be performed by the ECU 22 even when the valve 6 is fully opened.

In the fifth embodiment, a metal net is used as the deposit blocking portion 405b. Besides this,
As a configuration in which the deposit is preferentially attached to prevent the deposit from being deposited on the throttle valve 6 side, for example, a metal gasket 505 shown in FIG. 11 may be provided. In FIG. 11, a large number of protrusions 50
5c are arranged on the periphery of the center hole. When the projection 505c comes into contact with the exhaust gas flowing backward, a deposit component in the exhaust gas adheres. For this reason, adhesion of the deposit to the throttle valve 6 is suppressed, and the opening control operation of the throttle valve 6 can be maintained normally. The protrusion 505c protrudes only around the intake passage, and since there is a gap between the protrusions 505c, the protrusion 505c hardly affects the intake efficiency. Further, the production cost can be suppressed by press production or the like. The projection may be a thinner needle-like projection or a hairy flexible projection.

Although the embodiments of the present invention have been described above, the embodiments of the present invention include the following various technical items in addition to the technical items described in the claims. It should be noted that it has.

(1). The exhaust gas introduction device for an internal combustion engine according to any one of claims 1 to 12, wherein the idle speed control valve also serves as an intake port for intake air supplied bypassing the throttle valve.

[0078]

According to the first aspect of the present invention, the exhaust gas from the exhaust gas recirculation path is first introduced from the inflow port into the annular exhaust flow path in the wall of the tubular member.
Exhaust gas that has entered the annular exhaust flow path flows out of the inlet into the intake passage while flowing through the exhaust flow path. Since the exhaust passage is formed in an annular shape, the exhaust surface has an extremely large surface area, and theoretically an infinitely long exhaust passage is formed in the wall of the cylindrical member. , Heat is sufficiently absorbed. Since the exhaust gas thus sufficiently cooled is introduced into the intake air from the inlet, it is possible to prevent the downstream intake manifold from being thermally affected.

In the exhaust gas introduction device for an internal combustion engine according to the second aspect, a large amount of heat is exhausted by cooling the wall of the cylindrical member by air cooling or water cooling with respect to the configuration of the first aspect. Can be taken from. In particular, by cooling with water, more heat can be taken from the exhaust gas. Thus, the temperature of the exhaust gas introduced into the intake air can be sufficiently reduced, and the thermal effect on the intake manifold can be further reduced.

In the exhaust gas introduction device for an internal combustion engine according to the third aspect, the shape of the introduction port for introducing the gas into the intake passage from the annular exhaust passage in the wall of the cylindrical member is annular, and the exhaust guiding direction is Since the flow direction is the intake air, the exhaust gas blown out from the inlet into the intake passage is sent to the intake manifold side so as to surround the intake air flowing from the throttle body side. This allows
Exhaust gas having a sufficient flow velocity vigorously flows on the inner wall surface side of the intake passage, and the intake air is enveloped in the center of the vigorously flowing exhaust gas. For this reason, the flow velocity of the entire intake air should be increased against the wall resistance of the intake passage as compared with a case where the intake air is simply flowing or a case where the exhaust gas simply flows perpendicular to the intake air flow as in the related art. Can be. Therefore, the volume efficiency of the internal combustion engine can be improved.

According to a fourth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, the direction of exhaust flowing into the annular exhaust flow path is substantially the same as that of any one of the first to third aspects. By making it tangential, the exhaust can flow at high speed in the circumferential direction in the exhaust flow path, eliminating exhaust gas stagnation in the exhaust flow path, and allowing the exhaust to spread throughout the exhaust flow path. The cooled exhaust gas can be introduced into the intake passage from the introduction port.

According to a fifth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, a spiral exhaust guide fin is formed in the exhaust flow path, as compared with any one of the first to fourth aspects. In addition, the exhaust gas can be guided to smoothly flow in the circumferential direction in the exhaust flow channel, and the exhaust gas can be spread throughout the exhaust flow channel without stagnation in the exhaust flow channel. In addition, since all the exhaust is moved along the exhaust guide fins, the cooling distance is forcibly extended. As a result, the exhaust gas sufficiently cooled can be introduced into the intake passage from the inlet.

According to a sixth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, an inner wall and an outer wall are provided as the wall of the tubular member. I have. Therefore, it is possible to easily form the exhaust passage in the wall portion in the circumferential direction of the intake passage in an annular shape.

According to a seventh aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, cooling fins are formed on the outer peripheral surface of the structure of the sixth aspect. As a result, the heat radiation area increases, and the exhaust gas can be cooled more efficiently.

According to an eighth aspect of the present invention, the throttle body and the intake manifold are connected to each other by an outer wall portion. Thus, the exhaust passage and the inlet can be easily formed.

[0086] In the exhaust gas introduction device for an internal combustion engine according to the ninth aspect, the outer wall portion is deformable with respect to the configuration according to the eighth aspect. If the outer wall portion connects the throttle body and the intake manifold and the outer wall portion is deformable, the vibration of the internal combustion engine from the intake manifold side is difficult to be transmitted to the throttle body side, thereby preventing vibration. Produces an effect.

According to a tenth aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine, the outer wall portion is formed in a bellows-like shape in the structure of the ninth aspect. This allows the outer wall to be flexibly deformed against vibration. For this reason, a high vibration prevention effect is produced.

According to an eleventh aspect of the present invention, in the exhaust gas introduction device for an internal combustion engine according to any one of the first to tenth aspects, in the intake passage, upstream of the introduction port,
A deposit blocking portion is provided to prevent deposits due to exhaust gas flowing backward. By providing the deposit blocking portion in this manner, when there is a possibility that the exhaust gas flowing backward flows upstream from the inlet and deposits on the throttle body, the deposit component in the exhaust gas is preferentially removed by the deposit blocking portion. Can be deposited. For this reason, deposit accumulation on the throttle body side can be suppressed.

According to a twelfth aspect of the present invention, in addition to the configuration of the eleventh aspect, the deposit blocking portion is formed as a part of a gasket. As a result, the number of components does not increase, the manufacturing process can be simplified, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a gasoline engine for driving an automobile as a first embodiment.

FIG. 2 is a cross-sectional configuration diagram of the exhaust gas introduction device according to the first embodiment.

FIG. 3 is an explanatory diagram of a flow velocity distribution of intake air in the exhaust gas introduction device according to the first embodiment.

FIG. 4 is a sectional configuration diagram of an exhaust gas introduction device according to a second embodiment.

FIG. 5 is a cross-sectional configuration diagram of an exhaust gas introduction device according to a third embodiment.

FIG. 6 is a sectional view taken along the line AA of FIG. 5;

FIG. 7 is an explanatory diagram showing an arrangement state of exhaust guide fins in a third embodiment.

FIG. 8 is a cross-sectional configuration diagram of an exhaust gas introduction device according to a fourth embodiment.

FIG. 9 is a cross-sectional configuration diagram of an exhaust gas introduction device according to a fifth embodiment.

FIG. 10 is a front view of a metal gasket according to a fifth embodiment.

FIG. 11 is a front view of a metal gasket according to another embodiment.

[Explanation of symbols]

2 ... intake pipe, 4 ... throttle body, 4a ... flange, 5 ... metal gasket, 6 ... throttle valve, 7
a: Upstream flange, 7b: Downstream flange, 8 ...
Exhaust gas introduction device, 8a: pipe member, 9: heat insulating packing, 10
... Engine, 10a, 10b, 10c, 10d ... Cylinder, 12 ... Exhaust recirculation path, 12a ... Part of exhaust recirculation path, 1
4: Exhaust manifold, 16: Intake manifold, 16a: Flange, 18: Surge tank,
Reference Signs List 20: exhaust gas recirculation valve (EGR valve), 22: electronic control unit (ECU), 24: intake detour, 26: idle speed control valve, 30: tubular member, 3
2 ... intake passage, 34 ... wall, 36 ... exhaust passage, 36a ...
Downstream end, 38 ... inlet, 40 ... inlet, 108 ...
Exhaust gas introduction device, 130: cylindrical member, 130a: cooling fin, 132: intake passage, 134: wall, 134a
Downstream wall portion, 136: exhaust passage, 138: introduction port, 140: inlet, 208: exhaust introduction device, 208a
... pipe member, 230 ... cylindrical member, 232 ... intake passage, 23
4a: first cylindrical member, 234b: second cylindrical member, 234
c: third cylindrical member, 235a: flange portion, 235c
... Flange part, 236 ... Exhaust flow path, 238 ... Inlet, 2
40 inflow port, 244 exhaust exhaust fin, 250 water cooling chamber, 250a, 250b water pipe, 308 exhaust exhaust device, 308a pipe member, 330 tubular member, 332 intake passage, 334a inner wall, 334b: auxiliary wall portion, 33
4c: outer wall portion, 335a: flange portion, 335b, 3
35c: Flange portion, 336: Exhaust flow path, 338: Inlet, 405: Metal gasket, 405a: Gasket portion, 405b: Deposit blocking portion, 408: Exhaust introduction device, 432: Intake passage, 434a: Inner wall portion, 435a
... Flange part, 438 ... Inlet, 505 ... Metal gasket, 505c ... Protrusion.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Natsuhiko Katahira 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3G062 CA06 ED04 ED10 GA02 GA10 GA12 GA23

Claims (12)

[Claims] 1. An exhaust introduction device for an internal combustion engine for introducing exhaust gas into intake air from an exhaust gas recirculation passage, wherein the throttle body is interposed between a throttle body and an intake manifold and formed by an intake passage formed therein. A tubular member that guides intake air from the intake side to the intake manifold side, and is formed annularly in a circumferential direction of the intake passage in a wall portion of the cylindrical member that surrounds the intake passage, and exhausts the exhaust gas from the exhaust gas recirculation passage. An exhaust flow path for flowing, an inflow port provided in the tubular member for allowing exhaust gas from the exhaust gas recirculation path to flow into the exhaust flow path, and flowing in the exhaust flow path provided for the cylindrical member An exhaust introduction device for an internal combustion engine, comprising: an introduction port for introducing exhaust gas into the intake passage. 2. The exhaust gas introduction device for an internal combustion engine according to claim 1, wherein the wall is cooled by air cooling or water cooling. 3. The intake port is formed in an annular shape in the circumferential direction of the intake passage on the inner peripheral surface of the wall, and the exhaust guide direction is substantially the intake flow direction. The exhaust gas introduction device for an internal combustion engine according to claim 1 or 2, wherein: 4. The internal combustion engine according to claim 1, wherein the exhaust guide direction of the inflow port is formed so as to be substantially tangential to the annular exhaust flow path. Exhaust introduction device. 5. A spiral exhaust guide fin having an axis extending substantially in the axial direction of the tubular member is formed in the exhaust flow path.
5. The exhaust gas introduction device for an internal combustion engine according to any one of 4. 6. The device according to claim 1, wherein the wall portion includes an inner wall portion disposed inside the exhaust passage and an outer wall portion disposed outside the exhaust passage. 6. The exhaust gas introduction device for an internal combustion engine according to any one of 5. 7. The exhaust gas introduction device for an internal combustion engine according to claim 6, wherein cooling fins are formed on an outer peripheral surface of the outer wall portion. 8. The exhaust gas introduction device for an internal combustion engine according to claim 6, wherein a throttle body and an intake manifold are connected by the outer wall. 9. The exhaust gas introduction device for an internal combustion engine according to claim 8, wherein the outer wall portion is deformable. 10. The exhaust gas introduction device for an internal combustion engine according to claim 9, wherein the outer wall portion is formed in a bellows shape. 11. The internal combustion engine according to claim 1, further comprising a deposit blocking portion for blocking a deposit due to exhaust gas flowing backward in the intake passage upstream of the inlet. Exhaust introduction device. 12. The exhaust gas introduction of an internal combustion engine according to claim 11, wherein the deposit blocking portion is formed integrally with a gasket disposed between the throttle body and the cylindrical member. apparatus.