JP2020169633A - Intake manifold - Google Patents

Abstract

To provide an intake manifold for suppressing an increase in the external size.SOLUTION: An intake manifold 10 includes a surge tank 21 for suppressing the pulsation of intake air, a plurality of branch intake passages 23 connected to the surge tank 21 for intake air to be distributed therein, and an EGR introduction part 30 for introducing EGR gas into the branch intake passages 23, the branch intake passages 23 being circularly curved to encircle the surge tank 21, the EGR introduction part 30 being located in a range encircled by the branch intake passages 23.SELECTED DRAWING: Figure 2

Description

The present invention relates to an intake manifold.

As shown in FIG. 7, the intake manifold 100 of Patent Document 1 includes a substantially rectangular parallelepiped box-shaped surge tank 110 that suppresses the pulsation of intake air. A throttle valve (not shown) is arranged on the intake upstream side of the surge tank 110. Four branch intake passages 120 are connected to the intake downstream side of the surge tank 110. Each of the four branch intake passages 120 extends in an arc shape so as to surround the surge tank 110. The downstream ends of the four branch intake passages 120 are connected to the cylinder heads of the engine, respectively. Further, an EGR introduction portion 130 for introducing EGR gas is connected to an end portion of the branch intake passage 120 on the downstream side in the intake flow direction. The EGR introduction portion 130 is attached to the branch intake passage 120 from the outside of the arc.

JP-A-2016-121544

In the intake manifold as described in Patent Document 1, since the EGR introduction portion is attached to the branch intake passage from the outside, the EGR introduction portion is in a state of protruding outward from the branch intake passage. Therefore, the outer dimensions of the intake manifold become larger by the amount that the attached EGR introduction portion projects.

In order to solve the above problems, the present invention presents a surge tank that suppresses the pulsation of intake air, a plurality of branch intake passages that are connected to the surge tank and through which intake air flows, and an EGR that introduces EGR gas into the branch intake passage. An intake manifold including an introduction portion, wherein the branch intake passage is curved in an arc shape so as to surround the surge tank, and the EGR introduction portion is within a range surrounded by the branch intake passage. Is located in.

According to the above configuration, since the EGR introduction portion is located inside the arc of the branch intake passage, the EGR introduction portion does not project outward from the branch intake passage. Therefore, it is possible to prevent the outer dimensions of the intake manifold from becoming large due to the presence of the EGR introduction portion.

According to the present invention, it is possible to suppress an increase in the outer size of the intake manifold.

Perspective view of the intake manifold. An exploded perspective view of the intake manifold. Top view of the state where the third piece and the fourth piece are assembled. Top view of the third piece. FIG. 5-5 is a sectional view taken along line 5-5 in FIG. 6-6 sectional view in FIG. Perspective view of a conventional intake manifold.

Hereinafter, an embodiment of the intake manifold of the internal combustion engine will be described with reference to the drawings. In the following description, the vertical direction in FIGS. 1 and 2 will be the vertical direction of the intake manifold 10.

As shown in FIG. 1, the intake manifold 10 is provided with a surge tank 21 for suppressing intake pulsation. The surge tank 21 has a substantially rectangular parallelepiped box shape.
An intake intake portion 22 for intake intake from the outside of the vehicle is connected to a wall portion on one side in the longitudinal direction of the surge tank 21. The intake introduction portion 22 has a substantially cylindrical shape. Although not shown, another intake pipe is connected to the upstream end of the intake introduction section 22, and external intake air flows into the surge tank 21 via the intake introduction section 22.

Three branch intake passages 23 through which intake air flows are connected to the wall portion on one side of the surge tank 21 in the lateral direction. The branch intake passages 23 are arranged in the longitudinal direction of the surge tank 21. Each branch intake passage 23 is curved so as to surround the surge tank 21 from the side surface on one side of the surge tank 21 in the lateral direction, through the upper side of the surge tank 21, and to the other side in the lateral direction of the surge tank 21. Is extending.

A part of the inner peripheral surface of each branch intake passage 23 is in contact with the upper surface of the surge tank 21. In this embodiment, the central portion of each branch intake passage 23 in the extending direction is in contact with the surge tank 21. Further, as will be described later, a part of the inner peripheral surface of each branch intake passage 23 and the upper surface of the surge tank 21 are integrated, and both are fixed to each other.

The connection flange 24 projects from the outer peripheral surface of the end portion of each branch intake passage 23 opposite to the end portion connected to the surge tank 21. The connection flange 24 connects between the three branch intake passages 23. Each branch intake passage 23 is open at the end face of the connection flange 24. That is, in the branch intake passage 23, the surge tank 21 side is the intake upstream side, and the connection flange 24 side is the intake downstream side. Then, in the present embodiment, the surge tank 21, the intake intake portion 22, the branch intake passage 23, and the connection flange 24 constitute the intake manifold main body 20.

A connection port 25 for connecting an EGR pipe (not shown) is provided on the wall portion on the other side in the longitudinal direction of the surge tank 21. The connection port 25 has a substantially rhombus shape when viewed in a plan view. Bolt holes 26 for fixing the EGR pipe are recessed at both ends of the connection port 25 in the longitudinal direction. In the connection port 25, an EGR introduction opening 27 for inserting an EGR pipe is opened between the two bolt holes 26.

Further, as shown in FIG. 2, the intake manifold 10 is provided with an EGR introduction unit 30 for recirculating the EGR gas, which is the exhaust gas after combustion in the internal combustion engine, and introducing the EGR gas into each branch intake passage 23.

As shown in FIG. 3, the EGR introduction section 30 is composed of an EGR inflow section 40 into which the EGR gas flows in and a plurality of branch EGR passages 50 branched from the EGR inflow section 40 and connected to the branch intake passage 23. ing.

The first inflow portion 41 of the EGR inflow portion 40 has a circular tubular shape extending in the arrangement direction of the branch intake passage 23. One end of the first inflow portion 41 is connected to the EGR introduction opening 27. The other end of the first inflow portion 41 is located substantially in the center of the surge tank 21 in the arrangement direction of the branch intake passage 23.

A long, substantially square box-shaped second inflow portion 42 is connected to the other end of the first inflow portion 41. The second inflow portion 42 extends parallel to the longitudinal direction of the first inflow portion 41, and is arranged so as to be aligned with the first inflow portion 41. The substantially center of the second inflow portion 42 in the longitudinal direction is connected to the other end of the first inflow portion 41.

Two communication holes 42a are opened on the lower surface of the second inflow portion 42. One of the two communication holes 42a is arranged at one end of the second inflow portion 42 in the longitudinal direction, and the other one is arranged at the other end of the second inflow portion 42 in the longitudinal direction. There is. Further, the communication holes 42a are arranged between the adjacent branch intake passages 23 in the arrangement direction of the branch intake passages 23. That is, the communication holes 42a are arranged apart from each other in the arrangement direction of the branch intake passage 23.

A long, substantially square box-shaped third inflow portion 43 is connected below the lower surface of the second inflow portion 42. The third inflow portion 43 extends in the longitudinal direction of the first inflow portion 41. The length of the third inflow portion 43 in the longitudinal direction is substantially the entire length of the surge tank 21 in the longitudinal direction.

Two communication holes 43a are opened on the upper surface of the third inflow portion 43. The communication hole 43a has substantially the same inner diameter as the communication hole 42a of the second inflow portion 42. The two communication holes 43a are arranged so as to face each communication hole 42a of the second inflow portion 42.

As shown in FIG. 6, a cylindrical guide wall 43b extends downward from the opening edge of the communication hole 43a. The lower end of the guide wall 43b is located above the bottom surface inside the third inflow portion 43.

The two communication holes 42a and the two communication holes 43a communicate the internal space of the second inflow portion 42 and the internal space of the third inflow portion 43. That is, in the present embodiment, the second inflow portion 42 functions as an upstream inflow portion, the third inflow portion 43 functions as a downstream inflow portion, and the two communication holes 42a and the two communication holes 43a function as communication portions. ..

As shown in FIG. 4, three through holes 43c penetrate through the lower surface of the third inflow portion 43. The through hole 43c is arranged so as to be at the same position as each branch intake passage 23 in the arrangement direction of the branch intake passage 23.

One end of a circular tubular branch EGR passage 50 is connected to each of the three through holes 43c of the third inflow portion 43 from the outside of the third inflow portion 43. The other end of each branch EGR passage 50 is connected to the inner peripheral side of the arc of each branch intake passage 23 when viewed from the arrangement direction of the branch intake passage 23.

Further, as shown in FIG. 1, the other end of each branch EGR passage 50 is connected to an end portion on the intake downstream side of each branch intake passage 23, and in this embodiment, a portion immediately before the connection flange 24. That is, the other end of each branch EGR passage 50 is connected to the intake downstream side of each branch intake passage 23 with respect to the portion fixed to the upper surface of the surge tank 21.

The branch EGR passage 50 extends linearly. The branch EGR passage 50 is located closer to the branch intake passage 23 side of the branch EGR passage 50 on the intake downstream side of the branch intake passage 23. That is, as shown in FIG. 1, when viewed from the arrangement direction of the branch intake passages 23, the end of the branch EGR passage 50 on the branch intake passage 23 side is larger than the end of the branch EGR passage 50 on the surge tank 21 side. It is tilted so that it is located on the lower side.

Here, as shown in FIG. 2, the EGR inflow section 40 composed of the first inflow section 41, the second inflow section 42, and the third inflow section 43 is housed inside the surge tank 21. As shown in FIG. 6, the inside of the EGR inflow portion 40 is isolated from the space where the intake air is introduced inside the surge tank 21, and the gas cannot come and go.

As shown in FIG. 1, in the intake manifold 10, a virtual line segment connecting the lower end of the branch intake passage 23 and the lower end of the connection flange 24 when viewed from the arrangement direction of the branch intake passage 23 is a line segment. Let it be L. Then, when viewed from the arrangement direction of the branch intake passage 23, the range surrounded by the line segment L and the outer edge of the branch intake passage 23 is defined as the range R surrounded by the branch intake passage 23. At this time, since the EGR inflow portion 40 is arranged inside the surge tank 21, the EGR inflow portion 40 is arranged within the range R.

Further, as shown in FIG. 3, the branch EGR passage 50 is arranged between the surge tank 21 and the branch intake passage 23. Therefore, the branch EGR passage 50 is arranged within the range R. Therefore, the EGR introduction portion 30 composed of the EGR inflow portion 40 and the branch EGR passage 50 is arranged in the range R surrounded by the branch intake passage 23.

As shown in FIG. 2, the intake manifold 10 is composed of a plurality of pieces made of resin. Specifically, the intake manifold 10 is configured by integrating the first piece 11, the second piece 12, the third piece 13, and the fourth piece 14 by vibration welding.

The first piece 11 constitutes a part of the branch intake passage 23. Specifically, the first piece 11 constitutes substantially half of the outer peripheral side of the intermediate portion of the branch intake passage 23 in the extending direction. That is, the first piece 11 has a shape in which three semi-cylinders extending in an arc shape are arranged side by side.

The second piece 12 constitutes a part of the surge tank 21 and a part of the branch intake passage 23. Specifically, the second piece 12 constitutes substantially half of the upper side of the surge tank 21. Further, the second piece 12 constitutes substantially half of the inner peripheral side of the intermediate portion of the branch intake passage 23 in the extending direction. Further, in the second piece 12, a part of the inner peripheral surface of the branch intake passage 23 and the upper surface of the surge tank 21 are integrated. The second piece 12 constitutes an upper part of the second inflow portion 42 of the EGR inflow portion 40, that is, a lid portion of the second inflow portion 42. In addition, in FIG. 5 and FIG. 6, the portion of the EGR inflow portion 40 formed by the second piece 12 is virtually illustrated by a two-dot chain line.

As shown in FIG. 2, the third piece 13 constitutes a part of the surge tank 21, a part of the branch intake passage 23, a connection port 25, and a part of the EGR introduction portion 30. Specifically, the third piece 13 constitutes substantially half of the lower side of the surge tank 21 which is not composed of the second piece 12. Further, the third piece 13 constitutes an upstream portion and a downstream portion in the extension direction of the branch intake passage 23. Further, the third piece 13 constitutes a substantially half portion of the EGR inflow portion 40 on the lower side of the third inflow portion 43, and a branch EGR passage 50.

The fourth piece 14 constitutes the first inflow portion 41 of the EGR inflow portions 40. Further, the fourth piece 14 constitutes a lower portion of the second inflow portion 42 that is not composed of the second piece 12, that is, a portion other than the lid. Further, the fourth piece 14 constitutes substantially half of the upper side of the third inflow portion 43.

By fixing the fourth piece 14 inside the surge tank 21 portion of the third piece 13, the third inflow portion 43 of the EGR inflow portion 40 is partitioned. Then, by fixing the second piece 12 to the third piece 13 while the fourth piece 14 is fixed, the surge tank 21 is partitioned and the second inflow portion 42 of the EGR inflow portion 40 becomes. It is partitioned.

Next, the operation of this embodiment will be described.
When the internal combustion engine is being driven, intake air from the outside enters the surge tank 21 via the intake air introduction unit 22, and then flows through each branch intake passage 23. At this time, since the branch intake passage 23 is curved in an arc shape, a centrifugal force acts on the intake air flowing through the branch intake passage 23. Therefore, the intake air flowing through the branch intake passage 23 tends to flow on the outer peripheral side of the arc in the branch intake passage 23.

On the other hand, as shown in FIG. 3, the EGR gas introduced from the EGR introduction opening 27 flows from one end to the other end of the first inflow portion 41 of the EGR inflow portion 40. Next, as shown in FIG. 5, the EGR gas flowing through the first inflow section 41 flows from the first inflow section 41 into the second inflow section 42. Then, the EGR gas that has flowed into the second inflow portion 42 flows toward both ends of the second inflow portion 42, respectively. Next, as shown in FIG. 6, the EGR gas flowing through the second inflow portion 42 flows into the third inflow portion 43 through the communication hole 42a, the communication hole 43a, and the guide wall 43b. That is, the EGR gas flows into the third inflow section 43 from the two communication sections. Then, as shown in FIG. 5, the EGR gas that has flowed into the third inflow portion 43 flows into each branch EGR passage 50 through the three through holes 43c. Then, the EGR gas is introduced from each branch EGR passage 50 into each branch intake passage 23. At this time, the intake air flows through the inner peripheral side of the arc in the branch intake passage 23.

Next, the effect of this embodiment will be described.
(1) In the present embodiment, since the EGR introduction section 30 is located inside the arc of the branch intake passage 23, the EGR introduction section 30 does not project outward from the branch intake passage 23. Therefore, it is possible to prevent the outer dimensions of the intake manifold 10 from becoming large due to the presence of the EGR introduction portion 30. Specifically, the outer dimensions of the intake manifold 10 are the same as the outer dimensions of the intake manifold main body 20. Therefore, it is possible to prevent the outer dimensions of the intake manifold 10 from becoming larger than the outer dimensions of the intake manifold main body 20.

(2) In the present embodiment, the EGR inflow portion 40 of the EGR introduction portion 30 is arranged inside the surge tank 21. Therefore, it is not necessary to secure a space for arranging the EGR inflow portion 40 between the branch intake passage 23 and the surge tank 21. Therefore, when the EGR introduction portion 30 is arranged inside the arc of the branch intake passage 23, it is possible to prevent the outer dimensions of the branch intake passage 23 from becoming large. Further, the inside of the surge tank 21 has a relatively large space. Therefore, even if the EGR inflow portion 40 is arranged inside the surge tank 21, the function of the surge tank 21 is not easily hindered.

(3) In the present embodiment, the EGR gas is introduced on the inner peripheral side of the arc in the branch intake passage 23. On the other hand, in the branch intake passage 23, as described above, the intake air tends to circulate on the outer peripheral side of the arc. Therefore, the flow of intake air that easily flows on the outer peripheral side of the arc in the branch intake passage 23 is less likely to be obstructed by the flow of EGR gas introduced.

(4) In the present embodiment, the connection flange 24 is fixed to the cylinder head. Therefore, the intake manifold 10 is in a state of being cantilevered by a fixed portion of the connection flange 24 with respect to the cylinder head. In this case, if the branch EGR passage 50 is not connected to the intake downstream side of the surge tank 21 and the branch intake passage 23 fixed to the surge tank 21, it is fixed to the surge tank 21 in the branch intake passage 23. The part on the downstream side of the intake air is more likely to bend than the part where the intake is made, and the entire intake manifold is likely to vibrate. According to the above configuration, a portion of the branch intake passage on the downstream side of the intake air than the portion fixed to the surge tank is connected to the surge tank via the branch EGR passage. Therefore, the branch EGR passage functions like a beam connecting the surge tank and the branch EGR passage, and contributes to the improvement of the rigidity of the intake manifold.

(5) In the present embodiment, the branch EGR passage 50 is inclined so that the branch intake passage 23 side of the branch EGR passage 50 is located on the intake downstream side of the branch intake passage 23. The direction in which the EGR gas flows into the branch intake passage 23 tends to follow the direction in which the intake air flowing through the branch intake passage 23 flows. Therefore, the introduced EGR gas is less likely to obstruct the flow of intake air.

(6) In the present embodiment, the EGR gas that has flowed into the second inflow section 42 flows into the third inflow section 43 through a plurality of routes. By allowing the EGR gas to flow into the third inflow section 43 from the plurality of paths in this way, the amount of EGR gas flowing into the third inflow section 43 and the branch EGR passage 50 on the downstream side thereof can be made uniform.

(7) In the present embodiment, the linear branch EGR passage 50 is connected to the end of the branch intake passage 23 on the intake downstream side. Therefore, the distance through which the EGR gas flows in the branch intake passage 23 is short. As a result, since the EGR gas is unlikely to accumulate in the branch intake passage 23, the influence of heat on the branch intake passage 23 can be suppressed even if the EGR gas has a high temperature.

(8) In the present embodiment, the first inflow portion 41 extends from the EGR introduction opening 27 that opens on the surface on one end side in the arrangement direction of the branch intake passage 23 to substantially the center in the arrangement direction of the branch intake passage 23. Therefore, the EGR gas can flow to substantially the center in the longitudinal direction of the second inflow portion 42. Then, the EGR gas flows in two hands at the second inflow section 42, and then flows into each branch EGR passage 50 from the third inflow section 43. Therefore, when distributing the EGR gas to the three branch intake passages 23, the momentum of the flow of the EGR gas is weakened by dividing the EGR gas into two hands, and it is possible to suppress the variation in the amount introduced into the three branch intake passages 23. ..

(9) In the present embodiment, the other end of the first inflow portion 41 is connected to the second inflow portion 42. Therefore, the flow of EGR gas flowing through the first inflow portion 41 tends to weaken by colliding with the wall portion on the other end side of the first inflow portion 41. Therefore, in the second inflow portion 42, the momentum of the flow of the EGR gas is weakened, so that the amount of the EGR gas flowing out from the two communication holes 42a is easily equalized.

The above embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
The position of the EGR inflow portion 40 does not have to be inside the surge tank 21. For example, it may be outside the surge tank 21 and between the surge tank 21 and the branch intake passage 23. At least, the EGR inflow portion 40 and the branch EGR passage 50 may be located within the range R surrounded by the branch intake passage 23.

The end of the branch EGR passage 50 on the branch intake passage 23 side does not have to be connected to the inner peripheral side of the arc of the branch intake passage 23. For example, one end of the branch EGR passage 50 is connected to the EGR inflow portion 40, the branch EGR passage 50 extends through the inside of the branch intake passage 23, and the other end of the branch intake passage 23 is the branch intake passage 23. It may be open to the inside. At least, the branch EGR passage 50 may be located inside the range R surrounded by the branch intake passage 23.

The connection position of the branch EGR passage 50 with respect to the branch intake passage 23 is not limited to the example of the above embodiment. For example, the branch EGR passage 50 may be connected to the intake upstream side of the branch intake passage 23, which is fixed to the surge tank 21.

The extension direction of the branch EGR passage 50 is not limited to the example of the above embodiment. For example, the branch EGR passage 50 may be curved in the middle. The branch EGR passage 50 may be connected so as to be orthogonal to the branch intake passage 23. Further, the branch EGR passage 50 may extend so as to be located on the intake upstream flow side of the branch intake passage 23 toward the branch intake passage 23 side of the branch EGR passage 50.

The flow path configuration for equalizing the amount of EGR gas introduced into each branch EGR passage 50 in the EGR inflow section 40 is not limited to the example of the above embodiment. For example, the amount of EGR gas flowing into each branch EGR passage 50 may be equalized by adjusting the position and size of each hole.

The shape of the EGR inflow portion 40 can be any shape as long as the EGR gas can flow into the branched EGR passage 50. For example, the EGR inflow section 40 may have an integral box shape with no distinction such as a first inflow section 41, a second inflow section 42, and a third inflow section 43. Further, the EGR inflow portion 40 may have a shape having four or more inflow portions (spaces).

The position of the EGR introduction opening 27 is not limited to the example of the above embodiment. For example, it may be a side surface on one end side in the longitudinal direction of the surge tank 21, or may be a lower surface of the surge tank 21. In this case, the shape of the first inflow portion 41 may be appropriately changed according to the position of the EGR introduction opening 27. Further, the pipe portion may extend from the surge tank 21 and the opening at the tip of the pipe portion may function as the EGR introduction opening 27.

The configuration of the EGR introduction unit 30 is not limited to the example of the above embodiment. For example, when one end of three pipes is connected to the EGR introduction opening 27 and the other end of each pipe is connected to each branch intake passage 23, the three pipes function as the EGR introduction unit 30. In this case, the three pipes may be arranged in the range R surrounded by the branch intake passage 23.

-In the above embodiment, the case where the number of branch intake passages 23 is three is illustrated, but the number of branch intake passages 23 may be appropriately changed according to the number of cylinders in the internal combustion engine. When the branch intake passage 23 is changed, the number of branch EGR passages 50 may also be changed.

10 ... Intake manifold, 11 ... 1st piece, 12 ... 2nd piece, 13 ... 3rd piece, 14 ... 4th piece, 20 ... Intake manifold body, 21 ... Surge tank, 22 ... Intake introduction part, 23 ... Branch intake Passage, 24 ... connection flange, 25 ... connection port, 26 ... bolt hole, 27 ... EGR introduction opening, 26 ... connection part, 30 ... EGR introduction part, 40 ... EGR inflow part, 41 ... first inflow part, 42 ... first 2 Inflow part, 42a ... Communication hole, 43 ... Third inflow part, 43a ... Communication hole, 43b ... Guide wall, 43c ... Through hole, 50 ... Branch EGR passage.

Claims (6)

A surge tank that suppresses the pulsation of intake air,
A plurality of branch intake passages connected to the surge tank and through which intake air flows,
An EGR introduction section that introduces EGR gas into the branch intake passage,
It is an intake manifold equipped with
The branch intake passage is curved in an arc shape so as to surround the surge tank.
The EGR introduction portion is an intake manifold located within a range surrounded by the branch intake passage. The EGR introduction section includes an EGR inflow section into which the EGR gas flows, and a plurality of branch EGR passages that branch off from the EGR inflow section and are connected to the branch intake passage.
The intake manifold according to claim 1, wherein at least the EGR inflow portion of the EGR introduction portion is arranged inside the surge tank. The intake manifold according to claim 2, wherein the branch EGR passage extends from the surge tank and is connected to the inner peripheral side of the arc of the branch intake passage. The branch intake passage is a part of the extension direction different from the upstream end of the branch intake passage, and is fixed to the surge tank.
The intake manifold according to claim 3, wherein the branch EGR passage is connected to the intake downstream side of the branch intake passage fixed to the surge tank. The intake manifold according to claim 3 or 4, wherein the branch EGR passage is located closer to the branch intake passage side of the branch EGR passage on the intake downstream side of the branch intake passage. The EGR inflow section is
An upstream inflow portion extending in the arrangement direction of the branch intake passage and
A downstream inflow portion extending in the arrangement direction of the branch intake passage and connecting to the branch EGR passage,
A plurality of communication portions that communicate the internal space of the upstream side inflow portion and the internal space of the downstream side inflow portion are provided.
The intake manifold according to any one of claims 2 to 5, wherein the plurality of communication portions are arranged apart from each other in the arrangement direction of the branch intake passage.