JP7404993B2 - Engine additive gas supply device - Google Patents

Description

The present invention relates to an additive gas supply device for an engine.

2. Description of the Related Art As a conventional engine additive gas supply device, one described in Patent Document 1 is known. The device described in Patent Document 1 includes an EGR device that recirculates a portion of exhaust gas to the intake path. This EGR device has a small-diameter intake hole for adjusting the flow rate of exhaust gas between the intake manifold and the EGR pipe, and by optimizing the cross-sectional area of the intake hole, multiple This reduces variations in the flow rate of recirculated gas distributed to the cylinders.

Japanese Patent Application Publication No. 2007-211698

However, in conventional engine additive gas supply devices, pressure loss increases due to the provision of small-diameter intake holes in the path of the circulating exhaust gas, and a large amount of exhaust gas cannot flow into the intake passage. There was a problem that the purification performance deteriorated.

The present invention has been made in view of the above-mentioned circumstances, and provides an engine intake device that can evenly distribute a large amount of additive gas to a plurality of intake passages without increasing pressure loss. The purpose is to

The present invention provides a plurality of intake pipes that are arranged in a row in a cylinder row direction and have an intake passage formed therein for supplying air to the engine, an additive gas intake port that takes in additive gas, and a plurality of intake pipes each communicating with the intake passage. An additive gas supply device for an engine, comprising an additive gas supply pipe having a plurality of communication passages and a plurality of branch pipe parts arranged upstream of the communication passages and from which additive gas is supplied from the additive gas intake port. The branch pipe section has a curved surface projecting into the branch pipe section and has a protrusion on its inner wall that projects toward the upstream end of the communication path, and the communication path in the branch pipe section The passage cross section on the upstream side is larger than the passage cross section of the communication passage.

As described above, according to the present invention described above, it is possible to provide an engine intake device that can evenly distribute a large amount of additive gas to a plurality of intake passages without increasing pressure loss.

FIG. 1 is a perspective view of an engine additive gas supply device according to an embodiment of the present invention. FIG. 2 is a plan view of an additional gas supply device for an engine according to an embodiment of the present invention. FIG. 3 is a plan view showing an internal passage of an engine additive gas supply device according to an embodiment of the present invention. FIG. 4 is a bottom view of the upper member of the additive gas supply pipe of the additive gas supply device for an engine according to an embodiment of the present invention. FIG. 5 is a cross-sectional view of the additive gas supply device for the engine shown in FIG. 2 taken along the line VV. FIG. 6 is a sectional view of the additive gas supply device for the engine shown in FIG. 2 taken along the line VI-VI. FIG. 7 is a sectional view of the additive gas supply device for the engine shown in FIG. 2 taken along the line VII-VII. FIG. 8 is a cross-sectional view of the additive gas supply device for the engine shown in FIG. 2 taken along the direction of arrows VIII-VIII.

An additive gas supply device for an engine according to an embodiment of the present invention includes a plurality of intake pipes that are arranged in line in the cylinder row direction and have intake passages formed therein for supplying air to the engine, and a plurality of intake pipes that take in the additive gas. An additive gas supply pipe having an additive gas intake port, a plurality of communication passages each communicating with an intake passage, and a plurality of branch pipe sections disposed upstream of the communication passage and from which additive gas is supplied from the additive gas intake port. The branch pipe section has a protrusion on its inner wall that protrudes toward the upstream end of the communication passage, and the branch pipe section has a passage cross section on the upstream side of the communication passage. , is characterized by being larger than the passage cross section of the communication passage. As a result, the engine additive gas supply device according to the embodiment of the present invention can evenly distribute a large amount of additive gas to the plurality of intake passages without increasing pressure loss.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An engine additive gas supply device according to an embodiment of the present invention will be described below with reference to the drawings. 1 to 8 are diagrams showing an additional gas supply device for an engine according to an embodiment of the present invention. In Figures 1 to 8, the up, down, front, back, left and right directions refer to the up, down, front, back, left and right directions of the engine additive gas supply system installed in the vehicle, the direction orthogonal to the front and back direction is the left and right direction, and the height direction is up and down. It is the direction.

First, the configuration will be explained. In FIG. 2, the engine 1 includes an engine main body 1A. An intake manifold 20 is provided on the rear side of the engine body 1A. The intake manifold 20 distributes air that has passed through an air cleaner (not shown) to a plurality of intake ports of the engine body 1A. The engine 1 ignites and burns a mixture of air and fuel taken in from an intake port using an ignition plug (not shown), and discharges the burned exhaust gas from an exhaust outlet.

1 and 2, the intake manifold 20 includes a diverging portion 22 that branches from a surge tank (not shown) and has a downstream end connected to the engine main body 1A. , 24, 25. Intake passages 23A, 24A, and 25A that supply air to the engine 1 are formed inside the intake pipes 23, 24, and 25. The plurality of intake pipes 23, 24, 25 are arranged in parallel with each other along the cylinder row direction. A head side flange portion 26 is provided at the end of the intake pipes 23, 24, and 25 on the side of the engine body 1A, and the head side flange portion 26 is connected to the engine body 1A. The head side flange portion 26 extends in the cylinder row direction.

The intake manifold 20 is provided with an additive gas supply pipe 30 that introduces exhaust gas as an additive gas into the air flowing through the intake pipes 23, 24, and 25. The additive gas supply pipe 30 is provided on the upper surface of the intake manifold 20, and distributes and supplies additive gas introduced from an exhaust pipe (not shown) to each of the intake pipes 23, 24, and 25 of the intake manifold 20. The additive gas supply pipe 30 first branches into two routes: a route to the intake pipe 23 and another route, and then the other route branches into two routes: a route to the intake pipe 24 and a route to the intake pipe 25. It has a structure. In this way, the additional gas supply pipe 30 has a structure similar to a tournament table.

In FIG. 3, the additive gas supply pipe 30 has an additive gas intake port 38 at its upstream end to take in the additive gas. A flange portion 38A is provided around the additive gas intake port 38, and a pipe (not shown) for supplying additive gas is connected to the flange portion 38A.

The additive gas supply pipe 30 includes a first pipe part 31 extending from the additive gas intake port 38 in the cylinder row direction, and a second pipe part 32 extending from the downstream end of the first pipe part 31 in a cross direction intersecting the cylinder row direction. , a first branch pipe part 34 and a second branch pipe part 35 extending from the downstream end of the second pipe part 32 in opposite directions in the cylinder row direction. The first tube portion 31 and the second tube portion 32 are joined at a generally right angle at the joint portion 30A. The first branch pipe section 34 and the second branch pipe section 35 are bifurcated from a branch section 30C on the downstream end side of the second pipe section 32.

The additive gas supply pipe 30 includes a third pipe section 33 connected to the downstream end of the second branch pipe section 35, and a third branch pipe section 36 and a fourth branch pipe section 36 extending in opposite directions from the downstream end of the third pipe section 33. It has a branch pipe section 37. The second branch pipe portion 35 and the third pipe portion 33 are joined at a generally right angle at the joint portion 30B. The third branch pipe section 36 and the fourth branch pipe section 37 are bifurcated from the branch section 30D on the downstream end side of the third pipe section 33.

The first tube portion 31 and the second tube portion 32 have internal passages 31A and 32A formed in a straight line, respectively. The additive gas supply pipe 30 is made up of upper and lower members joined together. The internal passage 33A of the third pipe part 33, the internal passage 34A of the first branch pipe 34, the internal passage 35A of the second branch pipe 35, the internal passage 36A of the third branch pipe 36, and the internal passage 37A of the fourth branch pipe 37 are also It is formed in a straight line. FIG. 3 shows only the lower part of the additive gas supply pipe 30 so that the internal passages 31A, 32A, etc. can be visually observed.

A communication passage 34B communicating with the intake passage 23A of the intake pipe 23 is provided at the downstream end of the first branch pipe portion 34. A communication passage 36B communicating with the intake passage 24A of the intake pipe 24 is provided at the downstream end of the third branch pipe portion 36. A communication passage 37B communicating with the intake passage 25A of the intake pipe 25 is provided at the downstream end of the fourth branch pipe portion 37. The first branch pipe section 34, the second branch pipe section 35, the third branch pipe section 36, and the fourth branch pipe section 37 are located on the upstream side in the flow direction of the additive gas when viewed from the communication passages 34B, 36B, and 37B. It is located in

In FIG. 4, the inner walls of the first branch pipe section 34, the third branch pipe section 36, and the fourth branch pipe section 37 are provided with protrusions 34C, 36C, and 37C. The protrusions 34C, 36C, and 37C protrude toward the upstream ends of the communication passages 34B, 36B, and 37B.

In this embodiment, protrusions 34C, 36C, and 37C are provided at the upper portions of the first branch pipe section 34, the third branch pipe section 36, and the fourth branch pipe section 37, and the first branch pipe section 34, the third branch pipe section 37, and The upstream ends of the communication passages 34B, 36B, and 37B are located at the lower portions of the section 36 and the fourth branch pipe section 37, and the protrusions 34C, 36C, and 37C protrude downward.

In FIGS. 3 and 4, the first branch pipe section 34, the third branch pipe section 36, and the fourth branch pipe section 37 are formed in a cylindrical shape. Further, the second branch pipe section 35, the first pipe section 31, the second pipe section 32, and the third pipe section 33 are also formed in a cylindrical shape.

In FIG. 8, a passage cross section S1 on the upstream side of the communication passage 37B in the fourth branch pipe portion 37 is larger than a passage cross section S2 of the communication passage 37B.

As shown in FIGS. 4 and 8, the protrusion 37C has a curved surface centered on the central axis C1 extending in the cylinder row direction. The center axis C2 of the fourth branch pipe portion 37 extends obliquely with respect to the cylinder row direction (center axis C1). The protrusion 37C protrudes toward the central axis C2 of the fourth branch pipe portion 37. As shown in FIG. 8, in a cross section of the fourth branch pipe portion 37 perpendicular to the cylinder row direction, the curved surface forming the protrusion 37C protrudes to the vicinity of the central axis C2.

The curved surface of the protrusion 37C extends in the cylinder row direction at a predetermined cross section (see FIGS. 6, 7, and 8) orthogonal to the cylinder row direction (center axis C1). Further, as shown in FIGS. 6, 7, and 8, the amount of protrusion of the protrusion 37C increases toward the downstream side of the fourth branch pipe portion 37. Note that no protrusion 37C is formed at the upstream end of the fourth branch pipe portion 37 (see FIG. 5). The protrusions 34C and 36C of the first branch pipe part 34 and the third branch pipe part 36 are also configured similarly to the protrusion 37C of the fourth branch pipe part 37.

As explained above, in this embodiment, the first branch pipe section 34, the third branch pipe section 36, and the fourth branch pipe section 37 have inner walls protruding toward the upstream ends of the communication passages 34B, 36B, and 37B. It has protrusions 34C, 36C, and 37C. Further, a passage cross section S1 on the upstream side of the communication passage 37B in the fourth branch pipe portion 37 is larger than a passage cross section S2 of the communication passage 37B.

Thereby, the additive gas flowing through the first branch pipe section 34, the third branch pipe section 36, and the fourth branch pipe section 37 can be guided by the protrusions 34C, 36C, and 37C so as to be sent into the communication paths 34B, 36B, and 37B, The additive gas can be uniformly distributed to the intake passages 23A, 24A, 25A of the intake pipes 23, 24, 25. Further, since the passage cross section S1 on the upstream side of the communication passage 37B in the fourth branch pipe portion 37 is made larger than the passage cross section S2 of the communication passage 37B, the influence of pressure loss due to the provision of the protrusion 37C is reduced. be able to. As a result, a large amount of additive gas can be evenly distributed to the plurality of intake passages without increasing pressure loss.

Further, in this embodiment, the first branch pipe section 34, the third branch pipe section 36, and the fourth branch pipe section 37 are formed in a cylindrical shape. Further, the protrusion 37C has a curved surface that protrudes toward the central axis C2 of the fourth branch pipe portion 37. In a cross section perpendicular to the cylinder row direction, the curved surface forming the protrusion 37C protrudes to the vicinity of the central axis C2.

Thereby, by increasing the curved surface of the protrusion 37C toward the downstream side of the fourth branch pipe portion 37 and increasing the amount of protrusion, it is possible to enhance the effect of feeding the additive gas into the communication path 37B. Similarly, in the communication passages 34B and 36B, the curved surfaces of the protrusions 34C and 36C are made larger toward the downstream side of the first branch pipe section 34 and the third branch pipe section 36, thereby increasing the effect of feeding the additive gas. I can do it. In addition, while increasing the curved surface, the passage cross section S1 of the immediately upstream portion of the communication passages 34B, 36B, and 37B in the first branch pipe part 34, the third branch pipe part 36, and the fourth branch pipe part 37 is changed to the passage cross section S2 of the communication passage. It can be made larger more reliably.

Furthermore, in this embodiment, the central axis C2 of the fourth branch pipe portion 37 extends obliquely with respect to the cylinder row direction. The curved surface of the protrusion 37C extends in the cylinder row direction with a predetermined cross section perpendicular to the cylinder row direction. The amount of protrusion of the protrusion 37C increases toward the downstream side of the fourth branch pipe portion 37.

As a result, the amount of protrusion of the protrusion 37C gradually increases toward the downstream side of the fourth branch pipe section 37, so that the passage cross section of the fourth branch pipe section 37 can be changed gradually, and the additive gas can be smoothly distributed. can be guided to the communication path 37B.

Although embodiments of the invention have been disclosed, it will be apparent that modifications may be made by one skilled in the art without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

1... Engine, 1A... Engine body, 20... Intake manifold, 23, 24, 25... Intake pipe, 23A, 24A, 25A... Intake passage, 30... Additive gas supply pipe , 34...First branch pipe part (branch pipe part), 34B...Communication path, 34C...Protrusion, 36...Third branch pipe part (branch pipe part), 36B...Connection Passage, 36C...Protrusion, 37...Fourth branch pipe section (branch pipe section), 37B...Communication passage, 37C...Protrusion, 38...Additional gas intake port, C2.. .Central axis, S1...passage cross section, S2...passage cross section

Claims (3)

a plurality of intake pipes arranged in the direction of the cylinder rows and each having an intake passage formed therein for supplying air to the engine;
an additive gas intake port that takes in additive gas; a plurality of communication passages each communicating with the intake passage; and a plurality of branch pipe portions disposed upstream of the communication passage and to which the additive gas is supplied from the additive gas intake port. An additive gas supply device for an engine equipped with an additive gas supply pipe having,
The branch pipe section has a protrusion on its inner wall that is made of a curved surface that protrudes into the interior of the branch pipe section and that protrudes toward the upstream end of the communication path,
An additive gas supply device for an engine, wherein a passage cross section on an upstream side of the communication passage in the branch pipe portion is larger than a passage cross section of the communication passage. The branch pipe portion is formed in a cylindrical shape ,
The engine according to claim 1, wherein in a cross section of the branch pipe section perpendicular to the cylinder row direction, the curved surface forming the protrusion protrudes to the vicinity of a central axis of the branch pipe section. Additive gas supply device. The central axis of the branch pipe portion extends obliquely with respect to the cylinder row direction,
The curved surface has a predetermined cross-sectional shape in a cross section perpendicular to the cylinder row direction , and extends in the cylinder row direction with the predetermined cross-sectional shape ,
3. The additive gas supply device for an engine according to claim 2, wherein the amount of protrusion of the protrusion increases toward the downstream side of the branch pipe portion.

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