JP2021113544A - Intake device of internal combustion engine - Google Patents

Abstract

To provide an intake device of an internal combustion engine which enables pressure loss of intake air to be reduced.SOLUTION: An intake device 100 comprises a surge tank 2, a plurality of intake ports 3, and an upstream-side port 4 including a curved cylindrical bent portion 40, and connected to an upstream side of the surge tank 2. An inner surface 5 extending from the inside of the bent portion 40 toward the inside of the surge tank 2 includes; a first projected inner surface 6 formed outside the bent portion 40, extending along an intake flow direction, and bulged in a projected manner to the outside at a flow passage cross section; two second projected inner surfaces 7 which are arranged inside the bent portion 40, and adjoin each other at both sides of the first projected inner surface 6 at the flow passage cross section, and bulged in a projected manner at the outside at the flow passage cross section; and a recessed inner surface 8 which is formed to be sandwiched by two second projected inner surfaces 7 at the inside of the bent portion 40, and at the flow passage cross section, and recessed in a concave manner in the flow passage cross section.SELECTED DRAWING: Figure 1

Description

The present invention relates to an intake device for an internal combustion engine, and more particularly to an intake device for an internal combustion engine including a surge tank and a plurality of intake ports.

Conventionally, an intake device for an internal combustion engine including a surge tank and a plurality of intake ports is known (see, for example, Patent Document 1).

Patent Document 1 discloses an intake manifold including a surge tank, a plurality of branch paths for branching intake air from the surge tank, and an introduction flow path portion for introducing intake air into the surge tank.

Japanese Unexamined Patent Publication No. 2013-53582

Here, in the field of the intake device of an internal combustion engine, it has been conventionally required to improve the output and fuel consumption of the internal combustion engine by reducing the pressure loss of the intake air. In Patent Document 1, the aim is to improve the distribution performance between cylinders by reducing the pressure loss of one intake port among the plurality of intake ports, but the pressure loss of the other intake ports is reduced. Nothing is disclosed about what to do.

The present invention has been made to solve the above problems, and one object of the present invention is to provide an intake device capable of effectively reducing the pressure loss of intake air. ..

As a result of diligent studies by the inventor of the present application in order to achieve the above object, the side having a large radius of curvature of the bent portion on the inner surface extending from the inside of the bent portion of the upstream port that supplies intake air to the surge tank to the inside of the surge tank. One first convex inner surface that is arranged on the outside and extends along the direction of the intake air flow and bulges outward in a cross section of the flow path, and on the inside where the radius of curvature of the bent portion is small. In addition, two second convex inner surfaces that are arranged adjacent to both sides of the first convex inner surface in the flow path cross section, extend along the intake flow direction, and bulge outward in the flow path cross section. One concave shape that is arranged inside the curved portion on the side where the radius of curvature is small and is sandwiched between two second convex inner surfaces in the cross section of the flow path, and is recessed inward in the cross section of the flow path. It was found that the pressure loss of the intake air can be reduced by providing the inner surface, and the present invention was conceived.

That is, the intake device of the internal combustion engine in one aspect of the present invention is arranged in series with the surge tank along the longitudinal direction which is the intake flow direction of the surge tank, and a plurality of intake ports connected to the surge tank. And an upstream port that includes a tubular bend that curves along the intake flow direction and is connected to the upstream of the surge tank, and the inner surface that extends from the inside of the bend to the inside of the surge tank is a bend. It is arranged on the outside where the radius of curvature of Two second units that are arranged inward on the side and adjacent to both sides of the first convex inner surface in the flow path cross section, extend along the intake flow direction, and bulge outward in the flow path cross section. It is arranged so as to be sandwiched between the two convex inner surfaces and the inner side where the radius of curvature of the bent portion is small, and between the two second convex inner surfaces in the flow path cross section, and is concave inward in the flow path cross section. Includes one concave inner surface, which is recessed in.

Based on the above findings, in the intake device of the internal combustion engine according to one aspect of the present invention, the inner surface extending from the inside of the bent portion of the upstream port to the inside of the surge tank is configured as described above to form the intake device. The interior can be divided into a plurality (three) paths of intake air inside the first convex inner surface and each inner air intake path of the two second convex inner surfaces. Therefore, it is possible to generate a plurality of intake air flows (laminar flow) along a plurality of paths inside the surge tank. In this case, as described above, since the curved portion and the inside of the surge tank are divided into three paths, the distances from the inlet of the intake port to each path (each layer flow) can be made different from each other, and each path can be made different. It is possible to change the ease of inflow of intake air from the air to the inlet of the intake port. For example, if the route is close to the inlet of the intake port, the air flows directly from the upstream side (upstream port side) of the inlet of the intake port. Therefore, the upstream side of the inlet of the intake port is dominated (occupied) by a path close to the inlet of the intake port. In this case, if the route is far from the inlet of the intake port, the air flows in from the downstream side of the inlet of the intake port, avoiding (bypassing) the inlet of the intake port that is already controlled (occupied). In addition, it is possible to inflow the intake air to the other (all) intake ports in the same manner. In this way, the intake device can inject intake air from the three divided paths into the inlet of the intake port from different directions. That is, the intake air can flow in from a relatively large range with respect to the inlet of the intake port. As a result, the intake air can be effectively flowed into the intake port. Further, by providing the concave inner surface, it is possible to suppress the separation of the intake air at the bent portion, and the intake air is effectively flowed through the three paths, and the flow of the plurality of intake air along the above-mentioned plurality of paths ( Laminar flow) can be effectively generated. As described above, the intake air can be effectively flowed into each intake port. Therefore, the pressure loss of the intake air can be effectively reduced as compared with a general intake device in which only one intake path is provided inside the inner surface of the surge tank as in the conventional case. This point has been confirmed by simulation by the inventor of the present application.

In the intake system of the internal combustion engine according to the above one aspect, preferably, the upstream port is connected to one end of the plurality of intake ports in the arrangement direction with respect to the surge tank, and one first convex inner surface and two second. One of the three biconvex inner surfaces is located at a position connected to the inlets of a plurality of intake ports, and one of the three first convex inner surfaces and the two second convex inner surfaces. The other one is located at a distance from the inlets of the most plurality of intake ports in one first convex inner surface and two second convex inner surfaces.

With this configuration, the inlets of the intake ports of all of the plurality of paths (the intake path inside the first convex inner surface and the intake path inside each of the two second convex inner surfaces). Since the distances from the intake can be different from each other, the intake air can be taken in from a larger range with respect to the inlet of the intake port. As a result, the pressure loss of the intake air can be reduced more effectively.

In this case, preferably, each of the plurality of intake ports includes a funnel-shaped portion provided at the end connected to the surge tank, and three of one first convex inner surface and two second convex inner surfaces. The remaining one of the two is arranged along the funnel-shaped portion of the plurality of intake ports.

With this configuration, the remaining one path of the three of the one first convex inner surface and the two second convex inner surfaces is arranged along the funnel shape portion, so that the funnel shape portion has a path. Along with this, the intake air can be smoothly supplied to the intake port.

One of the three of the one first convex inner surface and the two second convex inner surfaces is arranged at a position connected to the inlets of a plurality of intake ports, and the other one is one first. In a configuration in which the convex inner surface and the two second convex inner surfaces are arranged apart from the inlets of the most plurality of intake ports, preferably in a direction orthogonal to the arrangement direction of the plurality of intake ports, 1 The other one of the three first convex inner surfaces and the two second convex inner surfaces is configured to gradually approach the inlet of the most downstream intake port as it goes downstream in the surge tank. Has been done.

With this configuration, the cross-sectional area of the flow path on the downstream side in the surge tank can be gradually reduced in accordance with the supply of intake air to the intake port on the upstream side, so that the pressure loss of the intake air is further effective. Can be reduced.

In this case, preferably, three of one first convex inner surface and two second convex inner surfaces in the flow path cross section where the most downstream intake port is located in a direction orthogonal to the arrangement direction of the plurality of intake ports. The other one of the three is better than the other one of the three, one first convex inner surface and two second convex inner surfaces in the flow path cross section where the most upstream intake port is located. It is located near the entrance of the intake port.

With this configuration, the other one path can be tilted so as to approach the inlet of the intake port on the downstream side, so that the intake air can be effectively supplied to the intake port on the downstream side.

In the intake device of the internal combustion engine according to the above one aspect, preferably, in the vicinity of the connection point between the surge tank and the bent portion, the cross-sectional area of the intake flow path is gradually expanded toward the downstream in the intake flow direction. It is configured.

With this configuration, it is possible to effectively reduce the pressure loss of the intake air due to the rapid expansion of the cross-sectional area of the flow path at the connection point between the surge tank and the bent portion.

The following configuration is also conceivable in the intake device of the internal combustion engine according to the above one aspect.

(Appendix 1)
That is, the intake air of the internal combustion engine having a configuration in which the remaining one of the three of the one first convex inner surface and the two second convex inner surfaces is arranged along the funnel-shaped portions of the plurality of intake ports. In the device, the first convex inner surface is arranged along the funnel-shaped portions of the plurality of intake ports, and one of the two second convex inner surfaces is connected to the inlets of the plurality of intake ports. The other of the two second convex inner surfaces is more distant from the inlets of the plurality of intake ports than one of the two second convex inner surfaces and the first convex inner surface. Have been placed.

With this configuration, it is possible to arrange the intake port so as to surround at least one first convex inner surface and one second convex inner surface, so that the intake port needs to be relatively long. In some models, the length of the intake port can be secured.

(Appendix 2)
Further, the intake air of the internal combustion engine having a configuration in which the remaining one of the three of the one first convex inner surface and the two second convex inner surfaces is arranged along the funnel-shaped portions of the plurality of intake ports. In the device, the first convex inner surface is arranged at a position connected to the inlets of the plurality of intake ports, and one of the two second convex inner surfaces is along the funnel-shaped portion of the plurality of intake ports. The other of the two second convex inner surfaces is more distant from the inlets of the plurality of intake ports than one of the two second convex inner surfaces and the first convex inner surface. Have been placed.

With this configuration, the intake port is connected from the side to the first convex inner surface arranged outside the bend, which is offset from the two second convex inner surfaces arranged inside the bend. Therefore, it is possible to suppress the size of the intake device in the height direction (the direction in which the two second convex inner surfaces and the first convex inner surface are aligned).

(Appendix 3)
Further, in the intake device of the internal combustion engine according to the above one aspect, each of the one first convex inner surface and the two second convex inner surfaces is circular, elliptical, oval, or rounded. It has a polygonal flow path cross section.

With this configuration, the pressure loss of the intake air can be more effectively reduced as compared with the case where each of the one first convex inner surface and the two second convex inner surfaces has a channel cross section having an angle. It can be reduced.

It is a front view which shows typically a part of the engine provided with the intake device by 1st Embodiment as a cross section. It is a side view of the intake device according to 1st Embodiment. The cross section of the intake device according to the first embodiment is shown in order from the upstream side in the intake flow direction, (A) is a cross-sectional view taken along the line 90-90 of FIG. 2, and (B) is 91 of FIG. It is a cross-sectional view taken along the line -91, (C) is a cross-sectional view taken along the line 92-92 of FIG. 2, and (D) is a cross-sectional view taken along the line 93-93 of FIG. It is a top view which showed only the inner surface of the intake device by 1st Embodiment. It is a front view which shows typically the intake device by 2nd Embodiment. It is a side view of the intake device according to 2nd Embodiment. The cross section of the intake device according to the second embodiment is shown in order from the upstream side in the intake flow direction, (A) is a cross-sectional view taken along the line 94-94 of FIG. 6, and (B) is 95 of FIG. It is a cross-sectional view taken along the line −95, (C) is a cross-sectional view taken along the line 96-96 of FIG. 6, and (D) is a cross-sectional view taken along the line 97-97 of FIG. It is a top view which showed only the inner surface of the intake device by 2nd Embodiment. It is sectional drawing of the intake device by 1st modification. It is sectional drawing of the intake device by 2nd modification. It is sectional drawing of the intake device by the 3rd modification. It is sectional drawing of the intake device by 4th modification. It is sectional drawing of the intake device by the 5th modification.

Hereinafter, embodiments will be described with reference to the drawings.

[First Embodiment]

The configuration of the intake device 101 of the engine 100 (an example of the “internal combustion engine” in the claims) according to the first embodiment will be described with reference to FIGS. 1 to 4.

(Engine configuration)
As shown in FIG. 1, the engine 100 for a vehicle (automobile) according to the first embodiment includes an engine main body 1 and an intake device 101. The engine 100 is an in-line multi (3) cylinder type engine. That is, the intake device 101 includes a plurality (three) intake ports 3 arranged in series.

The engine body 1 is provided with a combustion chamber 11, an intake valve 12 and an exhaust valve 13 that are periodically opened and closed. The engine body 1 reciprocates the piston P in a plurality of cylinders 14 extending in the vertical direction (only one is shown in FIG. 1) to adjust the intake air via the intake device 101 and expand the combustion chamber 11. By reducing the size, one cycle of intake, compression, expansion (combustion), and exhaust is continuously repeated.

Here, in each figure, the arrangement direction of the plurality of intake ports 3 (cylinder 14) is shown in the X direction. Of the X directions, the direction from the upstream side to the downstream side of the intake air flow direction in the surge tank 2 of the intake device 101 is indicated by the X2 direction, and the opposite direction is indicated by the X1 direction.

Further, in each figure, the vertical direction is shown by the Z direction. Of the Z directions, the upper part is indicated by the Z1 direction, and the lower part is indicated by the Z2 direction.

Further, in each figure, the directions orthogonal to the X direction and the Z direction are shown by the Y direction. One of the Y directions is indicated by the Y1 direction, and the other is indicated by the Y2 direction. The X direction and the Y direction are horizontal directions. In the description, the terms "downstream" and "upstream" mean "downstream" and "upstream" in the intake flow direction, respectively.

(Structure of intake device)
As shown in FIG. 1, the intake device 101 has one surge tank 2, a plurality of intake ports 3 (see FIG. 2) connected to the surge tank 2 from the downstream in the intake flow direction, and an intake flow to the surge tank 2. It includes one upstream port 4 connected from upstream in the direction.

<Surge tank configuration>
The surge tank 2 has a function of temporarily storing the intake air to level the intake air flowing into the plurality of intake ports 3 and evenly distribute the intake air. The surge tank 2 extends linearly in the X direction, which is the longitudinal direction. Further, the surge tank 2 takes in air from one first convex inner surface 6, two second convex inner surfaces 7 (70, 71), and one concave inner surface 8 when viewed from the X direction. Path (internal space) is formed in a clover shape (triangular shape). Details will be described later.

<Structure of intake port>
The plurality (three) intake ports 3 are arranged in series along the longitudinal direction (X direction), which is the intake flow direction of the surge tank 2. That is, the plurality (three) intake ports 3 are arranged so as to overlap each other when viewed from the X direction.

The plurality (three) intake ports 3 have an upstream end connected to the surge tank 2 from the lower side of the surge tank 2, and a downstream end connected to the engine body 1 via directly above the surge tank 2. It is connected. The plurality of intake ports 3 are curved so as to surround the surge tank 2 when viewed from the X direction.

Specifically, the plurality (three) intake ports 3 are connected to the Y2 direction side of the surge tank 2 from the Z2 direction side. The plurality of intake ports 3 are the lower side (Z2 direction side) of the surge tank 2 (one first convex inner surface 6 and two second convex inner surfaces 7) and the surge tank 2 when viewed from the X direction. The Y1 direction side and the upper side (Z1 direction side) of the surge tank 2 are curved so as to pass in order from upstream to downstream.

Each of the plurality (three) intake ports 3 includes a funnel-shaped portion 31. The funnel-shaped portion 31 is provided at an end portion on the upstream side in the intake flow direction connected to the surge tank 2. The funnel-shaped portion 31 is formed in a funnel shape so that the cross section of the intake flow path gradually decreases from the surge tank 2 toward the intake port 3. The funnel-shaped portion 31 has a function of reducing the pressure loss by preventing the cross section of the intake air passage from being suddenly reduced between the surge tank 2 and the intake port 3.

<Upstream port configuration>
As shown in FIG. 2, the upstream port 4 includes a tubular bent portion 40 curved along the intake flow direction and a perfect circular portion 41 connected to the bent portion 40 from the upstream in the intake flow direction. .. The perfect circle portion 41 has a cylindrical shape in which the cross section of the flow path is a perfect circle, and extends linearly.

The upstream port 4 (bent portion 40) is connected to the surge tank 2 at one end (end in the X1 direction) of the plurality of intake ports 3 in the arrangement direction.

<Structure of one first convex inner surface and two second convex inner surfaces>
As shown in FIG. 1, the inner surface 5 extending from the inside of the bent portion 40 to the inside of the surge tank 2 has one first convex inner surface 6 (“one first convex inner surface and one first convex inner surface” in the claims. An example of "the remaining one of the three of the two second convex inner surfaces") is included.

Further, the inner surface 5 has two second convex inner surfaces 7 (the second convex inner surface 70 on the Y2 direction side is "one first convex inner surface and two second convex inner surfaces" in the claims. An example of "one of the three inner surfaces", the second convex inner surface 71 on the Y1 direction side is the other of the three "one first convex inner surface and two second convex inner surfaces". An example of "one") is included.

Further, the inner surface 5 includes one concave inner surface 8. The one first convex inner surface 6, the two second convex inner surfaces 7, and the concave inner surface 8 are located downstream from the boundary 42 between the perfect circular portion 41 and the curved portion 40 in the intake flow direction. It is formed toward.

Further, the inner surface 5 is a lateral concave inner surface that is recessed inward in the cross section of the flow path in each of the one first convex inner surface 6 and the two second convex inner surfaces 7. Contains 8a.

The first convex inner surface 6 is arranged on the outer side (generally the lower side (Z2 direction side)) on which the radius of curvature of the bent portion 40 is large, and extends along the intake air flow direction. The first convex inner surface 6 bulges outward in the cross section of the flow path (see FIG. 3).

The two second convex inner surfaces 7 are on the inner side (generally the upper side (Z1 direction side)) on which the radius of curvature of the bent portion 40 is small, and on both sides of the first convex inner surface 6 in the flow path cross section. It is arranged adjacent to (Y1 direction side and Y2 direction side) and extends along the intake flow direction. The two second convex inner surfaces 7 bulge outward in the cross section of the flow path (see FIG. 3).

One concave inner surface 8 is arranged inside the curved portion 40 on the side where the radius of curvature is small, and is sandwiched between two second convex inner surfaces 7 in the cross section of the flow path (see FIG. 3). ). One concave inner surface 8 is recessed inward in the cross section of the flow path. As an example, one concave inner surface 8 is provided in a range from the bent portion 40 to the vicinity of the middle of the surge tank 2 in the X direction (see FIG. 2).

Therefore, the inner surface 5 extending from the inside of the bent portion 40 to the inside of the surge tank 2 is formed by one first convex inner surface 6, two second convex inner surfaces 7, and one concave inner surface 8. , It is formed in a clover shape (triangular shape).

Specifically, in a predetermined flow path cross section, one first convex inner surface 6 has an arc shape that bulges downward (Z2 direction side). Further, in a predetermined flow path cross section, one of the two second convex inner surfaces 7 (hereinafter referred to as the second convex inner surface 70) has an arc shape bulging in the Y2 direction side. Further, in a predetermined flow path cross section, the other of the two second convex inner surfaces 7 (hereinafter referred to as the second convex inner surface 71) has an arc shape bulging in the Y1 direction. The two second convex inner surfaces 7 are composed of one second convex inner surface 70 that swells in the Y2 direction and one second convex inner surface 71 that swells in the Y1 direction.

Each of the one first convex inner surface 6 and the two second convex inner surfaces 7 has a circular (arc-shaped) flow path cross section.

In a predetermined flow path cross section, on the downstream side of the upstream port 4 and inside the surge tank 2, a circular path 6a (space) along the first convex inner surface 6 and a second convex inner surface 70 are formed. A clover-shaped intake path is formed by a circular path 70a (space) along the circular path 70a (space) and a circular path 71a (space) along the second convex inner surface 71.

Here, in each figure, the center line of the route 6a is indicated by α, the center line of the route 70a is indicated by β, and the center line of the route 71a is indicated by γ.

The path 6a, the path 70a, and the path 71a may be arranged so as to overlap each other or may be arranged independently without overlapping each other, depending on the position in the intake flow direction. If the overlap of the paths 6a, 70a and 71a is large, the total flow path cross-sectional area is small, and if the mutual overlap is small, the total flow path cross-sectional area is large. The flow path cross-sectional areas of the respective paths (path 6a, path 70a and path 71a) are (omitted) equal.

In a predetermined flow path cross section, the two second convex inner surfaces 7 are arranged at substantially the same height position as each other. In a predetermined flow path cross section, one first convex inner surface 6 is arranged below the two second convex inner surfaces 7 and is arranged directly below one concave inner surface 8. ..

Here, as shown in FIG. 3, the intake device 101 increases the cross-sectional area of the intake flow path toward the downstream in the intake flow direction in the vicinity of the connection point between the surge tank 2 and the bent portion 40 of the upstream port 4. It is configured to expand gradually. The expansion of the cross-sectional area of the flow path of the intake air (change in the cross-sectional shape of the flow path from the perfect circle) is started from the boundary 42 (or the vicinity of the boundary 42) between the curved portion 40 and the perfect circle portion 41 of the upstream port 4. NS.

As an example, the cross-sectional area of the intake air passage is along the circular path 6a (center line α) along the first convex inner surface 6 and the second convex inner surface 70 described above. The circular path 70a (center line β) and the circular path 71a (center line γ) along the second convex inner surface 71 are gradually separated from each other toward the downstream in the intake flow direction. Enlarged by.

Further, the intake device 101 is configured to continue expanding the cross-sectional area of the flow path of the intake air to the vicinity of the most upstream intake port 3 in the X direction. The intake device 101 is configured to gradually reduce the cross-sectional area of the intake flow path toward the downstream side in the intake flow direction on the downstream side of the vicinity of the most upstream intake port 3 in the X direction. There is.

As an example, the cross-sectional area of the intake flow path is the second convex inner surface 71 with respect to the circular path 70a (center line β) along the second convex inner surface 70 described above. The circular path 71a (center line γ) along the line is reduced by gradually approaching the downstream in the intake flow direction (see FIG. 4).

As shown in FIG. 4, one first convex inner surface 6 is arranged along the funnel-shaped portion 31 of the plurality (three) intake ports 3. The first convex inner surface 6 (center line α) extends linearly in the X direction in the surge tank 2.

One of the two second convex inner surfaces 7 (the second convex inner surface 70 on the Y2 direction side) is arranged at a position connected to the inlets 32 of the plurality of intake ports 3. The second convex inner surface 70 is arranged at a position overlapping with the inlets 32 of the plurality of intake ports 3 when viewed from the upper side (Z1 direction). That is, the second convex inner surface 70 is arranged near the inlet 32 of the most plurality of intake ports 3 among the three of the one first convex inner surface 6 and the two second convex inner surfaces 7. ing. The second convex inner surface 70 (center line β) extends linearly in the X direction in the surge tank 2.

The other of the two second convex inner surfaces (the second convex inner surface 71 on the Y1 direction side) is one of the two second convex inner surfaces 7 (the second convex inner surface on the Y2 direction side). The surface 70) and the first convex inner surface 6 are arranged so as to be separated from the inlets 32 of the plurality of intake ports 3. The second convex inner surface 71 (center line γ) is slightly located in the surge tank 2 in the Surge tank 2 so that the downstream side is located closer to the Y2 direction when viewed from the upper side (Z1 direction side). It extends linearly in the direction of inclination.

Therefore, in the direction orthogonal to the arrangement direction (X direction) of the plurality of intake ports 3, the second convex inner surface 71 is the inlet 32 of the most downstream intake port 3 as it goes downstream in the surge tank 2. It is configured to gradually approach (Y2 direction side).

Further, in the direction orthogonal to the arrangement direction (X direction) of the plurality of intake ports 3, the most upstream intake port 3 is located on the second convex inner surface 71 in the flow path cross section where the most downstream intake port 3 is located. It is arranged closer to the inlet 32 of the intake port 3 than the second convex inner surface 71 in the cross section of the flow path.

<About the inflow of intake air from the surge tank to the intake port>
With reference to FIG. 4, the inflow of intake air from the surge tank 2 (each of the path 6a, the path 70a, and the path 71a) into the plurality (three) intake ports 3 will be described.

First, the inflow of intake air from the circular path 70a along the second convex inner surface 70 to the most upstream intake port 3 will be described.

As described above, since the second convex inner surface 70 is arranged at a position connected to the inlets 32 of the plurality of intake ports 3, the intake air from the path 70a is viewed from the upper side (Z1 direction side). , Directly flows into the inlet 32 of the intake port 3 from the upstream side (X1 direction side) of the inlet 32 of the intake port 3. Specifically, the intake air from the path 70a flows in from the range R1 to the inlet 32 of the intake port 3. Therefore, the upstream side (X1 direction side) (range R1) of the inlet 32 of the intake port 3 is dominated (occupied) by the intake air from the path 70a, and it becomes difficult for the intake air to flow in from the other routes 6a and 71a (omitted). It will not flow in). Similarly, the intake air flows into the other two intake ports 3 on the downstream side from the path 70a.

Next, the inflow of intake air from the circular path 6a along the first convex inner surface 6 to the most upstream intake port 3 will be described.

As described above, since the first convex inner surface 6 is arranged closer to the inlet 32 of the intake port 3 than the second convex inner surface 71, the intake air from the path 6a is already controlled. Avoiding R1, it flows into the inlet 32 of the intake port 3 from the range R2 located adjacent to the downstream side of the range R1. That is, the intake air from the path 6a flows into the inlet 32 of the intake port 3 from the Y1 direction side of the inlet 32 of the intake port 3 when viewed from the upper side (Z1 direction side). Therefore, the Y1 direction side (range R2) of the inlet 32 of the intake port 3 is dominated by the intake air from the path 6a (occupied by the intake air from the path 6a). Similarly, the intake air flows into the other two intake ports 3 on the downstream side from the path 6a.

Next, the inflow of intake air from the circular path 71a along the second convex inner surface 71 to the most upstream intake port 3 will be described.

As described above, since the second convex inner surface 71 is arranged farthest from the inlet 32 of the intake port 3, the intake from the path 71a avoids the already controlled range R1 and range R2. , From the range R3 located adjacent to the downstream side of the range R2, flows into the inlet 32 of the intake port 3. That is, the intake air from the path 71a bypasses the Y1 direction side of the inlet 32 of the intake port 3 when viewed from the upper side (Z1 direction side), and is downstream side (X2 direction side) of the inlet 32 of the intake port 3. ), It flows into the inlet 32 of the intake port 3. Similarly, the intake air flows into the other two intake ports 3 on the downstream side from the path 71a.

As described above, the intake device 101 has three intake paths 6a inside the first convex inner surface 6 and intake paths 70a and 71a inside the second convex inner surface 7 (70 and 71). The two intake paths allow the intake air to flow into the inlet 32 of the intake port 3 from different directions. Therefore, the intake device 101 is configured to allow intake air to flow in from a relatively large range with respect to the inlet 32 of the intake port 3. Therefore, the intake device 101 can effectively reduce the pressure loss of the intake air. This point has been confirmed by a simulation performed by the inventor of the present application.

(Effect of the first embodiment)
In the first embodiment, the following effects can be obtained.

In the first embodiment, the inner surface 5 extending from the inside of the bent portion 40 of the upstream port 4 to the inside of the surge tank 2 is configured as described above, whereby the inside of the intake device 101 is formed with the first convex inner surface. It can be divided into a plurality (three) paths of the inner intake path 6a of 6 and the inner intake paths 70a and 71a of the two second convex inner surfaces 7. Therefore, it is possible to generate a plurality of intake air flows (laminar flows) along a plurality of paths inside the surge tank 2. In this case, as described above, since the inside of the bent portion 40 and the surge tank 2 is divided into three paths, it is possible to make the distances from the inlet 32 of the intake port 3 to each path (each layer flow) different from each other. Therefore, the ease of inflow of intake air from each route to the inlet 32 of the intake port 3 can be changed. For example, if the route is close to the inlet 32 of the intake port 3, the air directly flows in from the upstream side (upstream port 4 side) of the inlet 32 of the intake port 3. Therefore, the upstream side of the inlet 32 of the intake port 3 is occupied (dominated) by a path close to the inlet 32 of the intake port 3. In this case, if the route is far from the inlet 32 of the intake port 3, the intake port 3 avoids (bypasses) the already occupied inlet 32 of the intake port 3 and flows in from the downstream side of the inlet 32 of the intake port 3. In addition, it is possible to inflow the intake air to the other (all) intake ports 3 in the same manner. In this way, the intake device 101 can inflow intake air into the inlet 32 of the intake port 3 from different directions from the three divided paths. That is, the intake air can flow in from a relatively large range with respect to the inlet 32 of the intake port 3. As a result, the intake air can be effectively flowed into the intake port 3. Further, by providing the concave inner surface 8, it is possible to suppress the separation of the intake air at the bent portion 40, and the intake air is effectively flowed through the three paths to receive the plurality of intake air along the above-mentioned plurality of paths. A flow (laminar flow) can be effectively generated. As described above, the intake air can be effectively flowed into each intake port 3. Therefore, the pressure loss of the intake air can be effectively reduced as compared with a general intake device in which only one intake path is provided inside the inner surface of the surge tank as in the conventional case.

In the first embodiment, as described above, the upstream port 4 is connected to one end of the plurality of intake ports 3 in the arrangement direction with respect to the surge tank 2, and "one first convex inner surface 6 and two. "One of the three of the second convex inner surface 7" is arranged at a position connected to the inlets 32 of the plurality of intake ports 3, and "one first convex inner surface 6 and two second convex". "The other one of the three of the inner surface 7" is separated from the inlet 32 of the most plurality of intake ports 3 in the one first convex inner surface 6 and the two second convex inner surfaces 7. Is arranged. As a result, the intake ports of all of the plurality of paths (the intake path 6a inside the first convex inner surface 6 and the intake paths 70a, 71a inside each of the two second convex inner surfaces 7). Since the distances from the inlet 32 of 3 can be made different from each other, the intake air can flow in from a larger range to the inlet 32 of the intake port 3. As a result, the pressure loss of the intake air can be reduced more effectively.

In the first embodiment, as described above, each of the plurality of intake ports 3 includes a funnel-shaped portion 31 provided at an end connected to the surge tank 2, and "one first convex inner surface 6 and The "remaining one of the three of the two second convex inner surfaces 7" is arranged along the funnel-shaped portion 31 of the plurality of intake ports 3. As a result, the path 6a of "the remaining one of the three of the one first convex inner surface 6 and the two second convex inner surfaces 7" is arranged along the funnel shape portion 31, and thus the funnel. The intake air can be smoothly supplied to the intake port 3 along the shape portion 31.

In the first embodiment, as described above, in the direction orthogonal to the arrangement direction of the plurality of intake ports 3, "one of the first convex inner surface 6 and the two second convex inner surfaces 7" The other one (path 71a) is configured to gradually approach the inlet 32 of the most downstream intake port 3 as it goes downstream in the surge tank 2. As a result, the cross-sectional area of the flow path on the downstream side in the surge tank 2 can be gradually reduced in accordance with the supply of intake air to the intake port 3 on the upstream side, so that the pressure loss of the intake air can be further effectively reduced. Can be reduced.

In the first embodiment, as described above, in the direction orthogonal to the arrangement direction of the plurality of intake ports 3, "one first convex inner surface 6 and 2 in the flow path cross section where the most downstream intake port 3 is located". The "other one of the three of the two second convex inner surfaces 7" is "one first convex inner surface 6 and two second convex inner surfaces in the flow path cross section where the most upstream intake port 3 is located". It is located closer to the inlet 32 of the intake port 3 than "the other one of the three on the inner surface 7." As a result, the other path 71a can be tilted so as to approach the inlet 32 of the intake port 3 on the downstream side, so that the intake air can be effectively supplied to the intake port 3 on the downstream side.

In the first embodiment, as described above, in the vicinity of the connection point between the surge tank 2 and the bent portion 40, the cross-sectional area of the intake air passage is gradually expanded toward the downstream in the intake air flow direction. ing. As a result, the pressure loss of the intake air due to the rapid expansion of the cross-sectional area of the flow path at the connection point between the surge tank 2 and the bent portion 40 can be effectively reduced.

In the first embodiment, as described above, the first convex inner surface 6 is arranged along the funnel-shaped portion 31 of the plurality of intake ports 3, and one of the two second convex inner surfaces 7 ( The second convex inner surface 70) is arranged at a position connected to the inlets 32 of the plurality of intake ports 3, and the other of the two second convex inner surfaces 7 (second convex inner surface 71) is It is arranged so as to be separated from the inlets 32 of the plurality of intake ports 3 by one of the two second convex inner surfaces 7 and the first convex inner surface 6. This makes it possible to arrange the intake port 3 so as to surround at least one first convex inner surface 6 and one second convex inner surface 71, so that the intake port 3 needs to be relatively long. In some models, the length of the intake port 3 can be secured.

In the first embodiment, as described above, each of the one first convex inner surface 6 and the two second convex inner surfaces 7 has a circular (arc-shaped) flow path cross section. As a result, the pressure loss of the intake air is more effectively reduced as compared with the case where each of the one first convex inner surface 6 and the two second convex inner surfaces 7 has a channel cross section having an angle. be able to.

[Second Embodiment]
The second embodiment will be described with reference to FIGS. 5 to 8. This second embodiment is different from the first embodiment in which a plurality of intake ports 3 are connected to the second convex inner surface 7, and the present invention relates to an example in which a plurality of intake ports 3 are connected to the first convex inner surface 206. explain. In the figure, the same configurations as those in the first embodiment are designated by the same reference numerals.

As shown in FIGS. 5 and 6, the intake device 201 according to the second embodiment includes one surge tank 202, a plurality of intake ports 3 connected to the surge tank 202 from the downstream in the intake flow direction, and a surge tank 202. It is provided with one upstream port 4 connected from the upstream in the intake flow direction.

As shown in FIG. 7, the inner surface 205 extending from the inside of the bent portion 40 of the intake device 201 to the inside of the surge tank 202 has one first convex inner surface 206 (“one first convex” in the claims. It includes an example of "one of three of the inner surface of the shape and the two second convex inner surfaces").

Further, the inner surface 205 has two second convex inner surfaces 207 (the second convex inner surface 270 on the Y1 direction side is claimed as "one first convex inner surface and two second convex inner surfaces". An example of "another one of the three inner surfaces", the second convex inner surface 271 on the Y2 direction side is "one of the first convex inner surface and two second convex inner surfaces". An example of "the remaining one") is included.

Further, the inner surface 205 includes one concave inner surface 8.

The two second convex inner surfaces 207 are composed of one second convex inner surface 270 that swells in the Y2 direction and one second convex inner surface 271 that swells in the Y1 direction.

As shown in FIG. 8, one first convex inner surface 206 is arranged at a position connected to the inlets 32 of a plurality (three) intake ports 3. The inlets 32 of the plurality of intake ports 3 are connected to the first convex inner surface 206 from the side (Y1 direction side) of one first convex inner surface 206. The first convex inner surface 206 (center line α) extends linearly in the X direction in the surge tank 202.

One of the two second convex inner surfaces 207 (the second convex inner surface 271 on the Y1 direction side) is arranged along the funnel-shaped portion 31 of the plurality of intake ports 3. The second convex inner surface 271 (center line γ) extends linearly in the X direction in the surge tank 202.

The other of the two second convex inner surfaces 207 (the second convex inner surface 270 on the Y2 direction side) is one of the first convex inner surface 206 and the two second convex inner surfaces 207 (the second convex inner surface 207). It is arranged more away from the inlets 32 of the plurality of intake ports 3 than the second convex inner surface 271). The second convex inner surface 270 (center line β) is slightly located in the surge tank 202 in the surge tank 202 so that the downstream side is located closer to the Y1 direction when viewed from the upper side (Z1 direction side). It extends linearly in the direction of inclination.

Therefore, in the direction orthogonal to the arrangement direction (X direction) of the plurality of intake ports 3, the other of the two second convex inner surfaces 207 (the second convex inner surface 270 on the Y2 direction side) is surged. It is configured to gradually approach the inlet 32 (Y1 direction side) of the most downstream intake port 3 as it goes downstream in the tank 202.

Further, in the direction orthogonal to the arrangement direction (X direction) of the plurality of intake ports 3, the most upstream intake port 3 is located on the second convex inner surface 270 in the flow path cross section where the most downstream intake port 3 is located. It is arranged closer to the inlet 32 of the intake port 3 than the second convex inner surface 270 in the flow path cross section.

<About the inflow of intake air from the surge tank to the intake port>
With reference to FIG. 8, the inflow of intake air from the surge tank 202 (each of the path 206a, the path 270a, and the path 271a) into the plurality (three) intake ports 3 will be described.

First, the inflow of intake air from the circular path 206a along the first convex inner surface 206 to the most upstream intake port 3 will be described.

As described above, since the first convex inner surface 206 is arranged at a position connected to the inlets 32 of the plurality of intake ports 3, the intake air from the path 206a is viewed from the upper side (Z1 direction side). , Directly flows into the inlet 32 of the intake port 3 from the upstream side (X1 direction side) of the inlet 32 of the intake port 3. Specifically, the intake air from the path 206a flows in from the range R10 to the inlet 32 of the intake port 3. Similarly, the intake air flows into the other two intake ports 3 on the downstream side from the path 206a.

Next, the inflow of intake air from the circular path 271a along the second convex inner surface 271 to the most upstream intake port 3 will be described.

As described above, since the second convex inner surface 271 is arranged closer to the inlet 32 of the intake port 3 than the second convex inner surface 270, the intake air from the path 271a is already dominated (occupied). It flows into the inlet 32 of the intake port 3 from the range R20 located adjacent to the downstream side of the range R10, avoiding the range R10. That is, the intake air from the path 271a flows into the inlet 32 of the intake port 3 from the Y1 direction side of the inlet 32 of the intake port 3 when viewed from the upper side (Z1 direction side). Therefore, the Y1 direction side (range R20) of the inlet 32 of the intake port 3 is dominated (occupied) by the intake air from the path 271a. Similarly, the intake air flows into the other two intake ports 3 on the downstream side from the path 271a.

Next, the inflow of intake air from the circular path 270a along the second convex inner surface 270 to the most upstream intake port 3 will be described.

As described above, since the second convex inner surface 270 is arranged farthest from the inlet 32 of the intake port 3, the intake from the path 270a avoids the already dominated ranges R10 and R20. , From the range R30 located adjacent to the downstream side of the range R20, flows into the inlet 32 of the intake port 3. That is, the intake air from the path 270a bypasses the Y2 direction side of the inlet 32 of the intake port 3 when viewed from the upper side (Z1 direction side), and is downstream of the inlet 32 of the intake port 3 (X2 direction side). ), It flows into the inlet 32 of the intake port 3. Similarly, the intake air flows into the other two intake ports 3 on the downstream side from the path 270a.

As described above, the intake device 201 includes the intake path 206a inside the first convex inner surface 206 and the intake paths 270a and 271a inside the two second convex inner surfaces 207 (270 and 271). The three intake paths of the above allow intake air to flow into the inlet 32 of the intake port 3 from different directions. Therefore, the intake device 201 is configured to allow intake air to flow in from a relatively large range with respect to the inlet 32 of the intake port 3. Therefore, the intake device 201 can effectively reduce the pressure loss of the intake air. This point has been confirmed by a simulation performed by the inventor of the present application.

Other configurations of the second embodiment are the same as those of the first embodiment.

(Effect of the second embodiment)
In the second embodiment, the following effects can be obtained.

In the second embodiment, the inner surface 205 extending from the inside of the bent portion 40 of the upstream port 4 to the inside of the surge tank 202 is configured as described above, thereby as in the conventional case, as in the first embodiment. Compared with a general intake device in which only one intake path is provided inside the inner surface of the surge tank, the pressure loss of the intake can be effectively reduced.

In the second embodiment, as described above, the first convex inner surface 206 is arranged at a position connected to the inlets 32 of the plurality of intake ports 3, and is one of the two second convex inner surfaces 207. (Second convex inner surface 271) is arranged along the funnel-shaped portion 31 of the plurality of intake ports 3, and the other of the two second convex inner surfaces 207 (second convex inner surface 270) is It is arranged so as to be separated from the inlets 32 of the plurality of intake ports 3 by one of the two second convex inner surfaces 207 and the first convex inner surface 206. As a result, the intake port 3 is connected from the side to the first convex inner surface 206 arranged outside the bent portion 40, which is offset from the two second convex inner surfaces 207 arranged inside the bent portion 40. Therefore, it is possible to suppress the size of the intake device 201 in the height direction (the alignment direction (Z direction) of the two second convex inner surfaces 207 and the first convex inner surface 206). can.

Other effects of the second embodiment are the same as those of the first embodiment.

(Modification example)
It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiment, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims.

For example, in the first and second embodiments, as shown in FIGS. 3 and 7, an example is shown in which the inner surfaces 5 and 205 include a laterally concave inner surface 8a. Is not limited to this. In the present invention, as in the first modification of the first embodiment shown in FIG. 9, the inner surface 305 does not include the laterally concave inner surface 8a, and the inner surface 305 is the first convex inner surface 6 and the first convex inner surface 6. It may include a flat surface 8b connecting the biconvex inner surface 7.

Further, in the first and second embodiments, an example is shown in which the inner surface includes a first convex inner surface and a second convex inner surface having a circular shape (arc shape), but the present invention is limited to this. do not have. In the present invention, as in the second modification of the first embodiment shown in FIG. 10, the first convex inner surface 406 having an inner surface 405 having a rounded rectangular shape (may be another shape such as an ellipse). And may include a second convex inner surface 407.

Further, in the first and second embodiments, an example is shown in which the inner surfaces include a first convex inner surface and a second convex inner surface having the same shape as each other, but the present invention is not limited to this. In the present invention, as in the third modification of the first embodiment shown in FIG. 11, the inner surface 505 may include a first convex inner surface 6 and a second convex inner surface 507 having different shapes from each other. .. The first convex inner surface 6 is formed in a circular shape (arc shape), and the second convex inner surface 507 is formed in a rounded rectangular shape. In this case, the flow path cross-sectional area of the inner path of the first convex inner surface 6 is smaller than the flow path cross-sectional area of the inner path of the second convex inner surface 507. Although not shown, on the contrary, the first convex inner surface may be formed in a rounded rectangular shape, and the second convex inner surface may be formed in a circular shape (arc shape).

Further, in the first and second embodiments, an example in which the inner path of the first convex inner surface and the inner path of the second convex inner surface are equalized has been shown. The present invention is not limited to this. In the present invention, as in the fourth modification of the first embodiment shown in FIG. 12, the flow path cross-sectional area of the path 606a inside the first convex inner surface 606 is set to the inside of the second convex inner surface 7. The flow path cross-sectional areas may be different from each other by making the flow path cross-sectional area of the path 7a larger than the flow path cross-sectional area.

Further, in the first and second embodiments, an example is shown in which the inner surface includes the first convex inner surface having a circular shape (arc shape), but the present invention is not limited to this. In the present invention, the inner surface 705 may include the first convex inner surface 706 which is oval (or elliptical) as in the fifth modification of the first embodiment shown in FIG. In this case, the longitudinal direction of the first convex inner surface 706 is the alignment direction (Y direction) of the two second convex inner surfaces 7. Further, in this case, the flow path cross-sectional area of the inner path of the first convex inner surface 706 is larger than the flow path cross-sectional area of the inner path of the second convex inner surface 7.

Further, in the first and second embodiments, an example including three intake ports has been shown, but the present invention is not limited to this. In the present invention, two or four or more intake ports may be provided.

Further, the arrangement of the three inner surfaces (one first convex inner surface and two second convex inner surfaces) with respect to the inlets of the plurality of intake ports is limited to the configurations shown in the first and second embodiments. do not have. In the present invention, any of the three inner surfaces (one first convex inner surface and two second convex inner surfaces) may be arranged at positions connected to the inlets of the plurality of intake ports. Further, any of the three inner surfaces (one first convex inner surface and two second convex inner surfaces) may be arranged apart from the inlets of the most plurality of intake ports. Further, the connection direction of the intake port may be any direction.

2,202 Surge tank 3 Intake port 4 Upstream port 5,205,305,405,505,705 Inner surface 6,206,406,606,706 First convex inner surface 7,207,407,507 Second convex Inner surface 8 Concave inner surface 31 Funnel shape 32 (intake port) inlet 40 Bend 100 Engine (internal combustion engine)
101, 201

Claims (6)

With a surge tank
A plurality of intake ports arranged in series along the longitudinal direction, which is the intake flow direction of the surge tank, and connected to the surge tank.
It includes an upstream port that includes a tubular bend that curves along the intake flow direction and is connected upstream of the surge tank.
The inner surface extending from the inside of the bent portion to the inside of the surge tank is
One first convex inner surface that is arranged on the outside where the radius of curvature of the bent portion is large, extends along the intake flow direction, and bulges outward in the cross section of the flow path.
It is arranged inside the bent portion on the side where the radius of curvature is small and adjacent to both sides of the first convex inner surface in the cross section of the flow path, extends along the intake flow direction, and is outside in the cross section of the flow path. Two second convex inner surfaces that bulge in the direction,
It is arranged inside the bent portion on the side where the radius of curvature is small and is sandwiched between the two second convex inner surfaces in the cross section of the flow path, and is recessed inward in the cross section of the flow path. Intake device, including one concave inner surface. The upstream port is connected to the surge tank at one end in the arrangement direction of the plurality of intake ports.
One of the three of the one first convex inner surface and the two second convex inner surfaces is arranged at a position connected to the inlets of the plurality of intake ports.
The other one of the three of the one first convex inner surface and the two second convex inner surfaces is the one first convex inner surface and the two second convex inner surfaces. The intake device according to claim 1, wherein the intake device is arranged so as to be separated from the inlets of the plurality of intake ports. Each of the plurality of intake ports includes a funnel-shaped portion provided at an end connected to the surge tank.
Claim that the remaining one of the three of the one first convex inner surface and the two second convex inner surfaces is arranged along the funnel-shaped portion of the plurality of intake ports. 2. The intake device according to 2. In the direction orthogonal to the arrangement direction of the plurality of intake ports, the other one of the three of the one first convex inner surface and the two second convex inner surfaces is in the surge tank. The intake device according to claim 2 or 3, which is configured to gradually approach the inlet of the intake port at the most downstream as it goes downstream. Three of the one first convex inner surface and the two second convex inner surfaces in the flow path cross section where the most downstream intake port is located in a direction orthogonal to the arrangement direction of the plurality of intake ports. The other one of them is the other one of the three of the one first convex inner surface and the two second convex inner surfaces in the flow path cross section where the most upstream intake port is located. The intake device according to claim 4, which is arranged closer to the inlet of the intake port. Any of claims 1 to 5, which is configured to gradually increase the cross-sectional area of the intake air passage toward the downstream side in the intake air flow direction in the vicinity of the connection point between the surge tank and the bent portion. The intake device according to item 1.

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