JP6783166B2 - Internal combustion engine intake system - Google Patents

Description

The present invention relates to an intake device for an internal combustion engine.

The intake device of the internal combustion engine includes an EGR gas pipe for returning a part of the exhaust gas from the internal combustion engine to the intake system as EGR gas. For example, in the intake device of Patent Document 1, a plurality of independent intake passages communicating with each cylinder of a multi-cylinder engine, a collector in which a plurality of independent intake passages are assembled in a state of being close to each other, and a collector are connected to the upstream side of the collector. It is provided with a common intake passage and an EGR gas introduction pipe connected to the downstream side of the collector. Further, inside the collector, an umbrella-shaped body is arranged to prevent the fresh air introduced into the collector from the common intake passage and the EGR gas introduced into the collector from the introduction pipe from facing each other. According to this, since the fresh air and the EGR gas do not collide with each other in the collector due to the umbrella-shaped body, the fresh air and the EGR gas flow smoothly in the collector, and the fresh air and the EGR gas flow into each independent intake passage. It is evenly distributed.

Japanese Unexamined Patent Publication No. 9-88745

By the way, in an internal combustion engine having a first bank and a second bank, for example, a V-type internal combustion engine, in order to make the combustion state in each cylinder of the first bank and the second bank uniform, the first It is necessary to equalize the amount of EGR gas flowing toward the first bank and the second bank.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an intake device for an internal combustion engine capable of equalizing the amount of EGR gas flowing toward the first bank and the second bank. To provide.

The exhaust gas recirculation device of an internal combustion engine that solves the above-mentioned problems is an intake pipe in which two branch pipes for the first bank and the second bank are connected to one fresh air intake pipe through which fresh air flows through a branch portion. And an EGR gas pipe for introducing EGR gas into the intake pipe, which is an intake device of an internal combustion engine, wherein the EGR gas pipe is connected to the branch portion of the intake pipe, and the EGR gas pipe is connected to the branch portion of the intake pipe. Around the opening of the EGR gas pipe, a partition wall is arranged to partition the EGR gas reservoir in which the EGR gas flows in and flows out toward the first bank and the second bank, and the EGR gas reservoir is provided. In the effective cross-sectional area of the first bank flow path where the EGR gas in the chamber flows out toward the branch pipe for the first bank and in the second bank flow path where the EGR gas flows out toward the branch pipe for the second bank. The effective cross-sectional area of the EGR gas pipe is smaller than the cross-sectional area of the flow path at the opening of the EGR gas pipe, and the EGR gas storage chamber is provided with a protruding wall protruding from the partition wall, and the protruding wall protrudes. The tip is on the side opposite to the partition wall with respect to the virtual straight line connecting the first portion of the partition wall forming the first bank flow path and the second portion of the partition wall forming the second bank flow path. positioned.

Pulsation is generated by alternately inhaling fresh air and EGR gas in the first bank and the second bank, and this pulsation causes EGR between the branch pipe for the first bank and the branch pipe for the second bank. A flow of EGR gas is generated that attempts to cross the gas reservoir. At this time, the protruding tip of the protruding wall is opposite to the partition wall rather than the virtual straight line connecting the first portion of the partition wall forming the first bank flow path and the second portion of the partition wall forming the second bank flow path. Since it is located on the side, the EGR gas that is going to cross the EGR gas storage chamber between the branch pipe for the first bank and the branch pipe for the second bank can be blocked by the protruding wall. Therefore, the amount of EGR gas flowing out from the EGR gas storage chamber to the branch pipe for the first bank via the flow path for the first bank and for the second bank from the EGR gas storage chamber via the flow path for the second bank. It is possible to prevent a variation in the amount of EGR gas flowing out to the branch pipe of the above. As a result, the amount of EGR gas flowing toward the first bank and the second bank can be equalized.

In the intake device of the internal combustion engine, it is preferable that the surface of the inner surface of the intake pipe forming the EGR gas reservoir, which faces the protruding tip of the protruding wall, is recessed.
According to this, it becomes easier to secure the volume of the EGR gas storage chamber as compared with the case where the surface of the inner surface forming the EGR gas storage chamber in the intake pipe on the side facing the protruding tip of the protruding wall is a flat surface. be able to. As a result, a certain amount of EGR gas stored in the EGR gas storage chamber can be easily discharged to the branch pipe for the first bank via the flow path for the first bank, and is stored in the EGR gas storage chamber. A certain amount of EGR gas can be easily discharged to the branch pipe for the second bank through the flow path for the second bank.

In the intake device of the internal combustion engine, the partition wall may have a shape that is convex toward the opening of the fresh air intake pipe.
According to this, the flow of fresh air flowing into the branch portion can be smoothed, and the resistance of the new air flow can be reduced. Therefore, fresh air can be smoothly flowed to each branch pipe.

According to the present invention, the amount of EGR gas flowing toward the first bank and the second bank can be equalized.

The schematic diagram of the intake device of the internal combustion engine in an embodiment. Partial perspective view of the intake device. Partial perspective view of the intake device. Partial sectional view of the intake device. Partial sectional view of the intake device. FIG. 3 is a partial cross-sectional view of an intake device according to another embodiment. FIG. 3 is a partial cross-sectional view of an intake device according to another embodiment.

Hereinafter, an embodiment in which the intake device of the internal combustion engine is embodied will be described with reference to FIGS. 1 to 5. The internal combustion engine of this embodiment is a V-type 6-cylinder diesel engine, which is mounted on a vehicle.

As shown in FIG. 1, the intake device 10 includes an intake pipe 20 and an EGR gas pipe 30 for introducing EGR gas into the intake pipe 20. The intake pipe 20 has one fresh air intake pipe 21 through which fresh air flows, and two branch pipes 22 and 23 branching from the fresh air intake pipe 21. The two branch pipes 22 and 23 are connected to the fresh air intake pipe 21 via the branch portion 24.

The internal combustion engine 50 has a right bank 51 as a first bank and a left bank 52 as a second bank. The right bank 51 and the left bank 52 each have three cylinders. The branch pipe 22 is a branch pipe for the right bank 51, and the branch pipe 23 is a branch pipe for the left bank 52.

An exhaust pipe 55 through which the exhaust gas discharged from the internal combustion engine 50 flows is connected to the internal combustion engine 50. The exhaust pipe 55 has a right bank exhaust pipe 55a and a left bank exhaust pipe 55b. An EGR gas pipe 30 is connected to the exhaust pipe 55. The EGR gas pipe 30 has a right bank EGR gas pipe 31a connected in the middle of the right bank exhaust pipe 55a and a left bank EGR gas pipe 31b connected in the middle of the left bank exhaust pipe 55b. ing.

The right bank EGR gas pipe 31a and the left bank EGR gas pipe 31b meet downstream in the flow direction of the exhaust gas. The EGR gas pipe 30 has a merging EGR gas pipe 31d connected to a merging portion 31c of the right bank EGR gas pipe 31a and the left bank EGR gas pipe 31b. The end of the merging EGR gas pipe 31d opposite to the merging portion 31c is connected to the branch portion 24 of the intake pipe 20. Therefore, the EGR gas pipe 30 is connected to the branch portion 24 of the intake pipe 20.

An EGR valve 32 is provided in the merging EGR gas pipe 31d. Then, by adjusting the valve opening degree of the EGR valve 32, the amount of EGR gas introduced from the merging EGR gas pipe 31d to the intake pipe 20 is adjusted. Further, the EGR gas pipe 31a for the right bank is provided with an EGR cooler 33a. The EGR cooler 33a cools the EGR gas flowing in the right bank EGR gas pipe 31a. Further, the EGR gas pipe 31b for the left bank is provided with an EGR cooler 33b. The EGR cooler 33b cools the EGR gas flowing in the left bank EGR gas pipe 31b.

A diesel throttle 27 is provided on the intake upstream side of the branch portion 24 of the fresh air intake pipe 21. Then, by adjusting the valve opening degree of the diesel throttle 27, the amount of fresh air introduced into the branch portion 24 is adjusted.

A part of the exhaust gas exhausted from the right bank 51 and flowing in the right bank exhaust pipe 55a flows in the right bank EGR gas pipe 31a and is exhausted from the left bank 52 and flows in the left bank exhaust pipe 55b. A part of the exhaust gas that flows flows in the EGR gas pipe 31b for the left bank. Then, the exhaust gas flowing in the right bank EGR gas pipe 31a and the exhaust gas flowing in the left bank EGR gas pipe 31b merge with the merging EGR gas pipe 31d via the merging portion 31c, and the merging EGR gas pipe It is introduced into the branch portion 24 of the intake pipe 20 via 31d.

As shown in FIGS. 2 and 3, the fresh air intake pipe 21, the branch pipes 22, 23, and the merging EGR gas pipe 31d are each circular tubular. The branch pipes 22 and 23 extend in directions separated from each other with respect to the branch portion 24, respectively. The fresh air intake pipe 21 extends in a direction orthogonal to the extending direction of the branch pipes 22 and 23 with respect to the branch portion 24. The merging EGR gas pipe 31d extends in a direction orthogonal to the branching portion 24 in the extending direction of the branching pipes 22 and 23 and also in the extending direction of the fresh air intake pipe 21.

As shown in FIG. 4, a partition wall 40 is arranged around the opening 30a of the EGR gas pipe 30 (merging EGR gas pipe 31d) in the intake pipe 20. The partition wall 40 has a top 43 arranged to face the opening 21a of the fresh air intake pipe 21 at the branch 24 of the intake pipe 20, and an oblique plate portion extending from the top 43 to both sides along the branch pipes 22 and 23. It has 41 and 42. Therefore, the partition wall 40 has a shape in which a flat plate-shaped long plate is bent from the top 43 as a base point. The partition wall 40 has a shape that is convex toward the opening 21a of the fresh air intake pipe 21. Both side edges of the partition wall 40 located in the lateral direction are continuous with the inner surface of the intake pipe 20.

The slanted plate portion 41 is formed as a wall extending in a downward slope in a direction in which the branch pipe 22 extends from the top 43 facing the central portion of the fresh air intake pipe 21 as a base point. The slanted plate portion 42 is formed as a wall extending in a downward slope in a direction in which the branch pipe 23 extends from the top 43. The inclination angles of both oblique plate portions 41 and 42 are the same. Further, the lengths of the oblique plate portions 41 and 42 in the extending direction are the same. It can be said that the top portion 43 is a connecting portion that connects the both oblique plate portions 41 and 42 to each other. The top 43 is formed in an arc shape that is convex toward the opening 21a of the fresh air intake pipe 21.

The partition wall 40 blocks the flow of EGR gas introduced into the branch portion 24 of the intake pipe 20 from the EGR gas pipe 30 to the fresh air intake pipe 21 side, and is introduced from the fresh air intake pipe 21 to the branch portion 24. Functions as a fresh air rectifying plate. That is, when fresh air is introduced from the fresh air intake pipe 21 to the branch portion 24, when the fresh air is taken in by the right bank 51, a flow C10 toward the branch pipe 22 is formed along the oblique plate portion 41. When the air is taken in by the left bank 52, the flow C11 toward the branch pipe 23 is formed along the oblique plate portion 42. In this way, the partition wall 40 functions as a straightening vane that smoothly guides the fresh air introduced from the fresh air intake pipe 21 to the branch portion 24 to the right bank 51 and the left bank 52.

The opening 30a of the EGR gas pipe 30 is located on the side of the intake pipe 20 opposite to the side of the top 43 of the partition wall 40 facing the fresh air intake pipe 21. Then, in the branch portion 24 of the intake pipe 20, the space surrounded by the partition wall 40 and the inner surface of the intake pipe 20 on the side opposite to the side facing the fresh air intake pipe 21 of the partition wall 40 becomes the EGR gas storage chamber R1. It has become. Therefore, the partition wall 40 partitions the EGR gas storage chamber R1.

There is a gap between the first end 40a, which is the end of the diagonal plate 41 of the partition wall 40 opposite to the top 43, and the inner surface of the intake pipe 20. This gap forms a right bank flow path C1 as a first bank flow path through which the EGR gas in the EGR gas storage chamber R1 flows out toward the branch pipe 22 for the right bank 51. Therefore, the first end portion 40a is the first portion of the partition wall 40 forming the right bank flow path C1.

There is a gap between the second end 40b, which is the end of the diagonal plate 42 of the partition wall 40 opposite to the top 43, and the inner surface of the intake pipe 20. This gap forms a left bank flow path C2 as a second bank flow path through which the EGR gas in the EGR gas storage chamber R1 flows out toward the branch pipe 23 for the left bank 52. Therefore, the second end portion 40b is the second portion of the partition wall 40 forming the left bank flow path C2.

As shown in FIGS. 4 and 5, the actual cross-sectional area S1 in the right bank flow path C1 and the actual cross-sectional area S2 in the left bank flow path C2 are flow cuts at the opening 30a of the EGR gas pipe 30. It is smaller than the area S3. Therefore, the effective cross-sectional area of the right bank flow path C1 and the effective cross-sectional area of the left bank flow path C2 are smaller than the flow path cross-sectional area S3 of the opening 30a of the EGR gas pipe 30.

As shown in FIG. 4, the EGR gas storage chamber R1 is provided with a protruding wall 44 protruding from the partition wall 40. The protruding wall 44 has a flat plate shape, and protrudes from a portion of the partition wall 40 on the top portion 43 opposite to the fresh air intake pipe 21. In the present embodiment, the protruding wall 44 is integrally formed with the partition wall 40. The protruding tip 44a of the protruding wall 44 is located on the opposite side of the partition wall 40 from the virtual straight line L1 connecting the first end portion 40a and the second end portion 40b of the partition wall 40. The partition wall 40 extends in a direction orthogonal to the virtual straight line L1. The protruding wall 44 overlaps the opening 30a in a direction extending with respect to the branch portion 24 of the merging EGR gas pipe 31d. Both side edges of the protruding wall 44 located in the lateral direction of the partition wall 40 are continuous with the inner surface of the intake pipe 20.

The inner surface 20a of the intake pipe 20 forming the EGR gas storage chamber R1 on the side facing the protruding tip 44a of the protruding wall 44 is recessed. The inner surface 20a of the intake pipe 20 is recessed around the protruding tip 44a so as to be separated from the protruding tip 44a of the protruding wall 44. The protruding tip 44a of the protruding wall 44 is located closer to the inner surface 20a of the intake pipe 20 than the opening 30a. The protruding tip 44a of the protruding wall 44 is separated from the inner surface 20a of the intake pipe 20. Therefore, the space on the right bank flow path C1 side of the protruding wall 44 in the EGR gas storage chamber R1 and the space on the left bank flow path C2 side of the protruding wall 44 in the EGR gas storage chamber R1 are the protruding wall 44. It communicates through a gap between the protruding tip 44a of the above and the inner surface 20a of the intake pipe 20.

Next, the operation of this embodiment will be described.
EGR gas flows into the EGR gas storage chamber R1 from the EGR gas pipe 30. Then, at the time of intake of the right bank 51, of the EGR gas stored in the EGR gas storage chamber R1, a certain amount of EGR gas flowing out from the right bank flow path C1 is introduced from the fresh air intake pipe 21 into the branch portion 24. It flows out to the branch pipe 22 and flows into the right bank 51 together with the fresh air. Further, at the time of intake of the left bank 52, a certain amount of EGR gas that flows out from the left bank flow path C2 out of the EGR gas stored in the EGR gas storage chamber R1 is introduced from the fresh air intake pipe 21 into the branch portion 24. It flows out to the branch pipe 23 and flows into the left bank 52 together with the fresh air.

Pulsation is generated by alternately inhaling fresh air and EGR gas in the right bank 51 and the left bank 52, and this pulsation causes a pulsation between the branch pipe 22 for the right bank 51 and the branch pipe 23 for the left bank 52. A flow of EGR gas is generated to cross the EGR gas reservoir R1. At this time, since the protruding tip 44a of the protruding wall 44 is located on the opposite side of the virtual straight line L1 connecting the first end 40a and the second end 40b of the partition wall 40 to the partition wall 40, the right bank 51 The EGR gas that intends to cross the EGR gas reservoir R1 between the branch pipe 22 for the left bank 52 and the branch pipe 23 for the left bank 52 is blocked by the protruding wall 44. Therefore, the amount of EGR gas flowing out from the EGR gas storage chamber R1 to the branch pipe 22 for the right bank 51 via the right bank flow path C1 and the left from the EGR gas storage chamber R1 via the left bank flow path C2. It is possible to prevent a variation in the amount of EGR gas flowing out to the branch pipe 23 for the bank 52. As a result, the amount of EGR gas flowing toward the right bank 51 and the left bank 52 is easily equalized.

In the above embodiment, the following effects can be obtained.
(1) The EGR gas storage chamber R1 is provided with a protruding wall 44 protruding from the partition wall 40. Since the protruding tip 44a of the protruding wall 44 is located on the side opposite to the partition wall 40 with respect to the virtual straight line L1, between the branch pipe 22 for the right bank 51 and the branch pipe 23 for the left bank 52. The EGR gas that is about to cross the EGR gas reservoir R1 can be blocked by the protruding wall 44. Therefore, the amount of EGR gas flowing out from the EGR gas storage chamber R1 to the branch pipe 22 for the right bank 51 via the right bank flow path C1 and the left from the EGR gas storage chamber R1 via the left bank flow path C2. It is possible to suppress the occurrence of variation in the amount of EGR gas flowing out to the branch pipe 23 for the bank 52. As a result, the amount of EGR gas flowing toward the right bank 51 and the left bank 52 can be equalized.

(2) The inner surface 20a of the intake pipe 20 is recessed. According to this, it is possible to easily secure the volume of the EGR gas storage chamber R1 as compared with the case where the inner surface 20a of the intake pipe 20 is a flat surface. As a result, a certain amount of EGR gas stored in the EGR gas storage chamber R1 can be easily discharged to the branch pipe 22 for the right bank 51 via the flow path C1 for the right bank, and the EGR gas can be easily discharged to the EGR gas storage chamber R1. A certain amount of the accumulated EGR gas can be easily discharged to the branch pipe 23 for the left bank 52 via the left bank flow path C2.

(3) The partition wall 40 has a shape that is convex toward the opening 21a of the fresh air intake pipe 21. According to this, the flow of fresh air flowing into the branch portion 24 can be smoothed, and the resistance of the new air flow can be reduced. Therefore, fresh air can be smoothly flowed to the branch pipes 22 and 23.

(4) Since the EGR gas is introduced into the branch portion 24 by connecting the merging EGR gas pipe 31d to the branch portion 24 of the intake pipe 20, the EGR gas pipe 30 is made to correspond to the branch pipes 22 and 23, respectively. The structure of the EGR gas pipe 30 can be simplified without the need for branching.

(5) By arranging the partition wall 40, it is possible to prevent the EGR gas from being blown back to the fresh air intake pipe 21. Therefore, it is possible to prevent the EGR gas from flowing into the fresh air intake pipe 21 and the EGR gas reaching the diesel throttle 27 to prevent impurities such as soot and unburned fuel from adhering to the diesel throttle 27. It is possible to avoid malfunction of the diesel throttle 27.

The above embodiment may be changed as follows.
○ As shown in FIG. 6, the partition wall 40 may not have a shape that is convex toward the opening 21a of the fresh air intake pipe 21, but may have a linear shape that extends toward the branch pipes 22 and 23, for example. In this case, the virtual straight line L1 connecting the first end portion 40a and the second end portion 40b of the partition wall 40 coincides with the surface of the partition wall 40 opposite to the side facing the fresh air intake pipe 21.

○ As shown in FIG. 7, the EGR gas pipe 30 has a branch portion 24 such that the opening 30a of the EGR gas pipe 30 is located at a portion of the branch portion 24 facing the opening 21a of the fresh air intake pipe 21. It may be connected to.

○ In the embodiment, the right bank flow path C1 may not be formed by the first end 40a of the partition wall 40. For example, the first end 40a side of the partition wall 40 is bent and formed by the bent portion. The right bank flow path C1 may be formed. Further, the left bank flow path C2 may not be formed by the second end 40b of the partition wall 40. For example, the second end 40b side of the partition wall 40 is bent and formed by the bent portion for the left bank. The flow path C2 may be formed.

○ In the embodiment, both side edges of the partition wall 40 located in the lateral direction may be separated from the inner surface of the intake pipe 20.
○ In the embodiment, both side edges of the protruding wall 44 located in the lateral direction of the partition wall 40 may be separated from the inner surface of the intake pipe 20.

○ In the embodiment, the protruding wall 44 may be a member different from the partition wall 40, or the protruding wall 44 may be attached to the partition wall 40.
○ In the embodiment, the fresh air intake pipe 21 may extend in a direction obliquely intersecting with the branch portion 24 in the direction in which the branch pipes 22 and 23 extend.

○ In the embodiment, the merging EGR gas pipe 31d may extend in a direction obliquely intersecting with the branch portion 24 in the direction in which the fresh air intake pipe 21 extends.
○ In the embodiment, the internal combustion engine 50 is a V-type 6-cylinder diesel engine, but the internal combustion engine is not limited to this, and is, for example, an internal combustion engine having a first bank and a second bank such as a boxer engine and a W-type engine. You may.

○ In the embodiment, the internal combustion engine 50 may be a non-diesel engine, for example, a gasoline engine. The number of cylinders in the first bank and the second bank is not particularly limited.

10 ... Intake device, 20 ... Intake pipe, 20a ... Inner surface, 21 ... Fresh air intake pipe, 21a ... Opening, 22, 23 ... Branch pipe, 24 ... Branch, 30 ... EGR gas pipe, 30a ... Opening, 40 ... partition wall, 40a ... first end portion which is the first part, 40b ... second end part which is the second part, 44 ... protruding wall, 44a ... protruding tip, 50 ... internal combustion engine, 51 ... right as the first bank Bank, 52 ... Left bank as the second bank, C1 ... Right bank flow path as the first bank flow path, C2 ... Left bank flow path as the second bank flow path, L1 ... Virtual straight line, R1 … EGR gas reservoir.

Claims (2)

An intake pipe in which two branch pipes for the first bank and the second bank are connected to one fresh air intake pipe through which fresh air flows via a branch portion.
An intake device for an internal combustion engine including an EGR gas pipe for introducing EGR gas into the intake pipe.
The EGR gas pipe is connected to the branch portion of the intake pipe,
A partition wall is arranged around the opening of the EGR gas pipe in the intake pipe to partition the EGR gas storage chamber in which the EGR gas flows in and flows out toward the first bank and the second bank. ,
The effective cross-sectional area in the flow path for the first bank where the EGR gas in the EGR gas reservoir flows out toward the branch pipe for the first bank and the second bank outflowing toward the branch pipe for the second bank. The effective cross-sectional area in the flow path is smaller than the cross-sectional area of the flow path at the opening of the EGR gas pipe.
The EGR gas storage chamber is provided with a protruding wall protruding from the partition wall.
The protruding tip of the protruding wall is more than a virtual straight line connecting the first portion of the partition wall forming the first bank flow path and the second portion of the partition wall forming the second bank flow path. located on the opposite side of the,
An intake device for an internal combustion engine, characterized in that the surface of the inner surface of the intake pipe forming the EGR gas reservoir, which faces the protruding tip of the protruding wall, is recessed . The intake device for an internal combustion engine according to claim 1, wherein the partition wall has a shape that is convex toward an opening of a fresh air intake pipe.

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