JP5881413B2 - Air supply manifold for internal combustion engines - Google Patents

Description

  The present invention relates to an air supply manifold for an internal combustion engine having a plurality of cylinders.

  In general, some internal combustion engines employ a structure that generates a swirl in a combustion chamber in an intake process for the purpose of improving combustibility. 7 and 8 show an example of a supply manifold of a multi-cylinder internal combustion engine having this structure. In these drawings, the internal combustion engine has a cylinder row in which a plurality of cylinders 8 are linearly arranged at equal intervals. FIG. 8 shows only one of the plurality of cylinders 8 as a representative. The air supply manifold 11 of the internal combustion engine is provided with an air supply collecting pipe 12 along the longitudinal direction of the cylinder row, and a plurality of air supply ports 15 branched from the air supply collecting tube 12 are provided in each cylinder row. It is connected to the cylinder 8. A vortex chamber 14 formed around the axis of the air supply valve 16 (see FIG. 2B) is provided between the air supply port 15 and the cylinder 8. In this air supply manifold 11, the air supplied from the air supply inlet 121 of the air supply introducing pipe 13 into the air supply collecting pipe 12 forms a swirl in the vortex chamber 14 through each air supply port 15, When the air valve 16 is opened, it flows into the cylinder 8 and forms a swirl of the air-fuel mixture also in the cylinder 8. By forming the swirl in the cylinder 8 in this way, the air-fuel mixture can be stably burned even in lean combustion, so that it is possible to reduce the fuel consumption and pollution of the internal combustion engine.

  In such an air supply manifold 11, since the shape of each air supply port 15 is the same, the main flow of the air supplied from the air supply inlet 121 to the air supply collecting pipe 12 is as shown by the arrows in FIG. It follows the flow path and flows into the air supply port 15. At this time, the relative positional relationship between the position of the air supply inlet 121 and the air supply port 15 is different for each of the plurality of air supply ports 15. Variation occurs in the swirl formed in the chamber 14. Due to the variation in swirl, the combustion in each cylinder 8 also varies, and there is a problem that exhaust gas and fuel consumption of the internal combustion engine deteriorate.

  Therefore, in Patent Document 1, a position near the upstream side of the intake outlet of the farthest intake port so that the swirl ratio of the cylinder corresponding to the intake port farthest from the intake inlet is approximately the same as the swirl ratio of other cylinders. We have proposed an intake manifold with a convex part. In this intake manifold, the uniformity of the swirl ratio between the cylinders can be maintained by the convex portion.

  Further, as a related technique, Patent Document 2 describes an intake manifold in which an intake manifold and a plurality of cylinders are each connected by an air supply port. In this intake manifold, the supply port has a configuration in which a bent portion that protrudes toward the center of the cylinder is formed at the connection portion with the intake port inlet for generating the intake swirl. By this bent portion, the maximum flow velocity portion of the intake air can be directed toward the center of the cylinder, and the strength of the swirl can be made substantially uniform.

Japanese Patent No. 3871807 Japanese Patent No. 4249919

  By the way, in an air supply manifold having a vortex chamber as described above, it is usually difficult to provide a large volume vortex chamber due to space limitations around the cylinder head, and it is effective in a limited vortex chamber space. It is necessary to form a swirl. For this purpose, it is desirable to allow a large amount of air to flow into the swirl start portion.

  However, in the conventional air supply manifold 11 as shown in FIGS. 7 and 8, the air supply port 15 extends substantially perpendicularly from the air supply collecting pipe 12, so that the air supply port far from the air supply inlet 121 is used. On the 15th wall side, the flow velocity is faster. Accordingly, when the swirl start portion of the swirl is located on the air supply inlet side, a region where the flow velocity is high is a vortex chamber 14 as seen in the cross-sectional flow velocity distribution of the air supply port 15 at the vortex chamber inlet shown in FIG. It will be located at the turning center. In this way, when the supply air flow into the vortex chamber 14 is introduced, if the supply air flow goes to the swirl center, it does not contribute to the formation of the swirl but directly flows into the cylinder and flows into the swirl swirl start portion of the vortex chamber. The air flow rate decreased and swirl could not be formed effectively. Further, since the cross-sectional flow velocity distribution of the air supply port 15 differs depending on the distance between the air supply inlet and the air supply port, swirl variation occurs between the plurality of cylinders.

Here, the intake manifold described in Patent Document 1 can introduce the supply air to the swirl swirl start portion of the vortex chamber by providing a protrusion in the intake port. There is a problem in that pressure loss occurs in the air and affects the formation of swirl, and the intake efficiency deteriorates.
On the other hand, the intake manifold described in Patent Document 2 does not have a vortex chamber, but forms a swirl by an air supply port in which a bent portion is formed. Therefore, there is no disclosure about a configuration for effectively forming a swirl by a vortex chamber.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an air supply manifold capable of effectively forming a swirl and suppressing the swirl variation between a plurality of cylinders. And

  An air supply manifold according to the present invention is connected to an air supply collecting pipe disposed along a longitudinal direction of a cylinder row in which a plurality of cylinders are arranged at equal intervals, and a cylinder head side end of each cylinder. An air supply manifold of an internal combustion engine, comprising: a plurality of vortex chambers that form swirls in the cylinder; and a plurality of air supply ports that connect the vortex chambers and the air supply collecting pipe, respectively. Among the plurality of air supply ports, the air supply port where the swirl swirl start portion of the vortex chamber is located on the main flow generation start side of the air supply collecting pipe with respect to the swirl center of the vortex chamber is the center of the air supply port The axial line is arranged so as to be eccentric from the center position of the inlet cross section of the vortex chamber toward the main flow generation starting point.

  In the air supply manifold, the air supply flow flowing into the air supply port from the air supply collecting pipe has a higher flow velocity on the side of the air supply port farther from the main flow generation starting point than on the wall on the near side. On the other hand, in the air supply port where the swirl swirl start portion of the vortex chamber is located on the main flow generation start side with respect to the swirl chamber swivel center, the swirl swirl of the vortex chamber is closer to the wall surface side of the supply port near the main flow generation start point. Since the start site is located, it was difficult to form a swirl well. Therefore, in the present invention, in the air supply port where the swirl swirl start portion is located on the main flow generation start side, the central axis of the air supply port is decentered from the center position of the inlet cross section of the vortex chamber to the main flow generation start side. Therefore, the flow velocity flowing into the swirl turning start site becomes faster. As a result, the ability of the vortex chamber can be efficiently exhibited without wastefully losing pressure, and a swirl can be effectively formed. That is, by decentering the air supply port, the angle between the tangential direction of the vortex chamber flow path at the swirl start portion and the central axis of the air supply port becomes smaller or coincides, so Supply air can be introduced in the tangential direction, and a strong swirl can be formed. Further, in the present invention, a good swirl can be formed only by decentering the position of the air supply port without changing the positions of a plurality of cylinders arranged at equal intervals. There is no need to make significant changes. The main flow generation start point is a portion that is the start point of the main supply air flow in the supply air collecting pipe.

In the above air supply manifold, there are two or more air supply ports in which the central axis of the air supply port is decentered from the center of the inlet cross section of the vortex chamber toward the main flow generation start side. This air supply port preferably has a larger amount of eccentricity than the other air supply port located farther from the main flow generation starting point than the one air supply port.
This is because the flow velocity distribution in the air supply port becomes larger as it is closer to the main flow generation starting point, so that the eccentricity of the air supply port closer to the main flow generation starting point is made larger than the air supply port on the far side, so that The flow velocity distribution of the vortex chamber inlet cross section in the chamber can be made substantially uniform, and swirl variation in each cylinder can be suppressed.

Alternatively, in the air supply manifold, when there are two or more air supply ports in which the central axis of the air supply port is eccentric to the main flow generation start side from the center of the inlet cross section of the vortex chamber, the main flow It is preferable that the eccentric amount of the air supply port is set in inverse proportion to the distance between the generation starting point and a line passing through the swirling center of the vortex chamber and perpendicular to the air supply collecting pipe.
In this way, by adjusting the amount of eccentricity according to the distance between the main flow generation start point and the line passing through the swirling center of the vortex chamber and perpendicular to the air supply collecting pipe, the flow velocity distribution of the vortex chamber inlet cross section in a plurality of vortex chambers Can be made substantially uniform with high accuracy, and variations in swirl within each cylinder can be suppressed.

In the air supply manifold, of the plurality of air supply ports, an air supply port in which a swirl swirl start portion of the vortex chamber is located on a side opposite to the main flow generation start point with respect to the swirl center of the vortex chamber is It is preferable that the central axis of the air supply port is disposed so as to be eccentric from the center position of the inlet cross section of the vortex chamber toward the main flow generation starting point.
When the swirl swirl start part of the vortex chamber is located on the opposite side of the main flow generation start point with respect to the swirl center swirl center, the flow rate of the air supplied from the air supply port to the swirl swirl start part of the vortex chamber becomes excessive. In this case, the air supply port is arranged so that the central axis of the air supply port is decentered from the center position of the inlet cross section of the vortex chamber to the main flow generation start side. To do. Thereby, the air supply flow rate flowing into the swirl swirl start portion of the vortex chamber can be reduced, and the variation of the swirl in each cylinder can be further suppressed.

In the air supply manifold, the main flow generation starting point may be an air supply inlet of the air supply collecting pipe.
Alternatively, in the air supply manifold, the main flow generation starting point may be a position where the air supplied from the air supply inlet of the air supply collecting pipe collides with the wall surface of the air supply collecting pipe.

  In the present invention, in the air supply port where the swirl swirl start site is located on the main flow generation start side, the central axis of the air supply port is eccentric to the main flow generation start side from the center position of the inlet cross section of the vortex chamber. The flow velocity flowing into the swirl turning start site becomes faster. As a result, the ability of the vortex chamber can be efficiently exhibited without wastefully losing pressure, and a swirl can be effectively formed. That is, by decentering the air supply port, the angle between the tangential direction of the vortex chamber flow path at the swirl start portion and the central axis of the air supply port becomes smaller or coincides, so Supply air can be introduced in the tangential direction, and a strong swirl can be formed. Further, in the present invention, a good swirl can be formed only by decentering the position of the air supply port without changing the positions of a plurality of cylinders arranged at equal intervals. There is no need to make significant changes.

It is a top view of the air supply manifold which concerns on 1st Embodiment of this invention. (A) is a diagram in which the cross-sectional flow velocity distribution of the air supply port is superimposed on the cross section along line AA in FIG. 1, and (B) is a superposition of the cross-sectional flow velocity distribution of the air supply port on the cross sectional view along line BB in FIG. FIG. It is a top view of the air supply manifold which shows the 1st modification of 1st Embodiment. It is a top view of the air supply manifold which shows the 2nd modification of 1st Embodiment. It is a top view of the air supply manifold which shows the 3rd modification of 1st Embodiment. It is a top view of the air supply manifold which concerns on 2nd Embodiment of this invention. It is a top view of the conventional air supply manifold. It is a perspective view of the conventional air supply manifold.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

[First Embodiment]
FIG. 1 is a plan view of an air supply manifold according to the first embodiment of the present invention. In this embodiment, as an example, an air supply manifold 1 applied to an internal combustion engine having a cylinder row in which three cylinders (not shown) are arranged at equal intervals and in a straight line will be described. However, in the present embodiment, the number of cylinders of the internal combustion engine is not limited to three. For the sake of simplicity, the longitudinal direction of the cylinder row is referred to as the X direction, and each cylinder is referred to as the first cylinder, the second cylinder, and the third cylinder from the end in the X direction.

In FIG. 1, the air supply manifold 1 includes an air supply collecting pipe 2, a plurality of vortex chambers 4 (4 a to 4 c), and a plurality of air supply ports 5 (5 a to 5 c).
The air supply collecting pipe 2 is a long pipe line, and is arranged in the X direction along the cylinder row. An air supply introduction pipe 3 extending from the front side to the back side of the drawing is connected to the air supply collection pipe 2, and an air supply inlet 21 for introducing supply air from the supply air introduction pipe 3 to the supply air collection pipe 2 is supplied. It is provided in the internal space of the air collecting tube 2. In the figure, the air supply introduction path 21 is provided between the second air supply port 5b and the third air supply port 5c, and the air supply inlet 21 which is the main flow generation starting point is directed toward the wall surface of the air supply collecting pipe 2 on the cylinder side. Open.

  The vortex chamber 4 is provided at each cylinder head side end of each cylinder. The vortex chamber 4 and the cylinder communicate with each other, and the opening of the vortex chamber 4 to the cylinder is opened and closed by an air supply valve 6 shown in FIG. Here, FIG. 2A is a diagram in which the cross-sectional flow velocity distribution of the air supply port is superimposed and displayed on the cross section along the line AA in FIG. The vortex chamber 4 is configured to form a swirl around the axis of the air supply valve 6. Therefore, the swirl center 41 of the vortex chamber coincides with the axis of the air supply valve 6. In FIG. 1, the vortex chamber 4 is formed such that a swirl swirl start portion 42 is disposed on the air supply inlet 21 side. The first vortex chamber 4a provided in the first cylinder, the second vortex chamber 4b provided in the second cylinder, and the third vortex chamber 4c provided in the third cylinder are all in the same direction in the turning start portion 42. Are arranged so as to form a swirl in the same turning direction.

The air supply ports 5 a to 5 c are substantially straight flow paths that connect the plurality of vortex chambers 4 a to 4 c and the air supply collecting pipe 2, respectively. In the drawing, the central axes of the air supply ports 5a to 5c are indicated by two-dot chain lines 1 to m.
In the air supply manifold 1, the air supplied from the air supply introduction pipe 3 to the air supply collecting pipe 2 flows into the air supply ports 5a to 5c through the air supply collecting pipe 2, and the air supply ports 5a to 5c. It further flows into the vortex chambers 4a to 4c from 5c. Then, the supply air is supplied into the cylinder while forming swirls in the vortex chambers 4a to 4c.

In the present embodiment, the air supply port 5 further has the following configuration.
Of the plurality of air supply ports 5, the swirl swirl start portions 42 of the vortex chambers 4 a and 4 b are located on the air supply inlet 21 side of the air supply collecting pipe 2 with respect to the swivel center 41. The air supply port 5b is arranged so that the central axes 1 and m of the air supply ports 5a and 5b are eccentric to the air supply inlet 21 side from the center positions C and D of the inlet cross sections 43a and 43b of the vortex chambers 4a and 4b. ing. The third air supply port 5c, in which the swirl swirl start portion 42 of the vortex chamber 4c is located on the opposite side of the air supply inlet 21 of the air supply collecting pipe 2 with respect to the swivel center 41, is similar to the conventional art. The central axis n of the port 5c and the central position E of the inlet cross section 43c of the vortex chamber 4 are arranged so as to substantially coincide. In the first air supply port 5a and the second air supply port 5b, the contours represented by dotted lines in the drawing indicate the air supply ports in the prior art.

  Here, in the air supply manifold 11 having the conventional configuration shown in FIG. 7 described above, the air supply flow flowing into the air supply port 15 from the air supply collecting pipe 12 is directed toward the wall surface of the air supply port 15 farther from the air supply inlet 121. The flow velocity is faster than the wall on the near side. That is, as shown in FIG. 2B, in the flow velocity distribution of the air supply port cross section, a region having a high flow velocity is formed on the side of the air supply port wall far from the air supply inlet 121. Here, FIG. 2B is a diagram in which the cross-sectional flow velocity distribution of the air supply port 15 is superimposed on the cross-sectional view taken along the line BB in FIG. In contrast, in the air supply port 15 where the swirl swirl start portion 142 of the vortex chamber 14 is located on the air supply inlet 121 side with respect to the swirl center 141 of the vortex chamber 14, the air supply port wall surface close to the air supply inlet 121. Since the swirl swirl start portion 142 of the vortex chamber 14 is located on the side, it is difficult to form the swirl well.

  Therefore, in the present embodiment, in the first supply port 5a and the second supply port 5b in which the swirl turning start portion 42 is located on the supply inlet 21 side, the central axes l and m of the supply ports 5a and 5b are The center positions C and E of the inlet cross section 43 of the vortex chambers 4a and 4b are eccentric from the air supply inlet 21 side. As a result, as shown in FIG. 2A, in the flow velocity distribution of the air supply port cross section, the region where the flow velocity is fast moves to the swirl turning start portion 42 side, and the flow velocity flowing into the swirl turning start portion 42 increases. Therefore, the capability of the vortex chamber 4 can be efficiently exhibited without wastefully losing pressure, and a swirl can be effectively formed. That is, as shown in FIG. 1, by decentering the first air supply port 5a, the angle θ between the tangential direction T of the vortex chamber flow path at the swirl start portion 42 and the central axis l of the air supply port 5a is reduced. Therefore, the air supply can flow in from the air supply port 5a in the direction substantially tangential to the vortex chamber 4a, and a strong swirl can be formed. Further, in the present embodiment, it is possible to form a good swirl by simply decentering the position of the air supply port 5 without changing the positions of a plurality of cylinders arranged at equal intervals. There is no need to change the design significantly.

  Further, it is preferable that the second air supply port 5b close to the air supply inlet 21 has a larger amount of eccentricity than the first air supply port 5a located farther from the air supply inlet 21. This is because the flow velocity distribution in the air supply ports 5a and 5b becomes larger as it is closer to the air supply inlet 21, so that the second air supply port 5b on the side closer to the air supply inlet 21 is made closer to the first air supply port 5a on the far side. By increasing the amount of eccentricity, the flow velocity distribution of the vortex chamber inlet cross-section 43 in the plurality of vortex chambers 4a to 4c can be made substantially uniform, and swirl variation in each cylinder can be suppressed.

Furthermore, the eccentricity of the air supply port 5 is inversely proportional to the distance between the air supply inlet 21 and the lines Q and R orthogonal to the axis of the air supply collecting pipe 2 through the swirl centers 41 of the vortex chambers 4a and 4b. An amount may be set. That is, since the distance d1 between the air supply inlet 21 and the line Q passing through the vortex chamber 4a is larger than the distance d2 between the air supply inlet 21 and the line R passing through the vortex chamber 4b, the eccentric amount of the first air supply port 5a is The eccentric amount of the second air supply port 5b is made smaller.
In this way, the eccentricity of the air supply ports 5a and 5b is adjusted according to the distance between the air supply inlet 21 and the line passing through the swivel center 41 of the vortex chambers 4a and 4b and perpendicular to the axis of the air supply collecting pipe 2. As a result, the flow velocity distribution at the vortex chamber inlet cross section in the plurality of vortex chambers 4a and 4b can be made substantially uniform with high accuracy, and variation in swirl in each cylinder can be suppressed.

  In the above-described embodiment, the case where the supply air introduction pipe 3 and the supply air inlet 21 are provided between the second supply air port 5b and the third supply air port 5c is shown as an example. The position of the air supply inlet 21 is not limited to this, and may be configured as shown in FIG. 3 or FIG.

  FIG. 3 is a plan view of an air supply manifold showing a first modification of the present embodiment. The air supply manifold 1 has a structure in which an air supply introduction pipe 3 is provided between a first air supply port 5a and a second air supply port 5b. In this case, only the first air supply port 5a has the swirl turning start portion 42 positioned on the air supply inlet 21 side. Therefore, the central axis 1 of the first air supply port 5a is decentered toward the X-direction air supply inlet 21 with respect to the center position C from the inlet cross section 43a of the vortex chamber 4a.

  FIG. 4 is a plan view of an air supply manifold showing a second modification of the present embodiment. The air supply manifold 1 has a structure in which the air supply introduction pipe 3 is provided on the end side of the air supply collecting pipe 2 from the third air supply port 5c. In this case, the swirl turning start portion 42 is positioned on the supply air inlet 21 side in all of the first supply port 5a to the third supply port 5c. Accordingly, all of the first supply port 5a to the third supply port 5c are decentered toward the X-direction supply inlet 21 side.

  In the present embodiment, the case where the main flow generation start point is the supply inlet 21 of the supply air collection pipe 2 has been described. However, the present invention is not limited to this, and the main flow generation start point is the supply air supply pipe 2 of the supply air collection pipe 2. It is good also as a position where the supply air introduced from the air inlet 21 collides with the wall surface of the supply air collecting pipe 2. In particular, as shown in the third modification of FIG. 5, when the direction of the air flow introduced from the air supply inlet 21 is inclined with respect to the longitudinal direction of the air supply collecting pipe 2, A point G that extends from the center in the inflow direction and intersects the opposite end face of the air supply collecting pipe 2 is preferably a main flow generation starting point.

[Second Embodiment]
Next, an air supply manifold according to the second embodiment will be described with reference to FIG. Here, FIG. 6 is a plan view of an air supply manifold according to the second embodiment of the present invention.
The air supply manifold 1 ′ of the present embodiment is the same as the air supply manifold 1 of the first embodiment already described, except for the position change of the air supply ports 5 ′ (5a ′ to 5c ′) and the air supply introduction pipe 3 ′. It is the same composition. Therefore, here, the same reference numerals are given to members common to the first embodiment, and the description thereof is omitted, and the description will focus on parts different from the first embodiment.

  The air supply manifold 1 'according to the present embodiment includes an air supply collecting pipe 2', a plurality of vortex chambers 4 '(4a' to 4c '), and a plurality of air supply ports 5' (5a 'to 5c'). Consists of In the air supply manifold 1 ′, the swirl swirl start portion 42 ′ of the vortex chamber 4 ′ is located on the side opposite to the air supply inlet 21 ′ with respect to the swivel center 41 ′ of the vortex chamber 4 ′. In the case of such a configuration, there is a possibility that the air supply flow rate flowing from the air supply port 5 ′ into the swirl swirl start portion 42 ′ of the vortex chamber 4 ′ becomes excessive. Accordingly, the central axes l ′ and m ′ of the first air supply port 5a ′ and the second air supply port 5b ′ are set at the air supply inlet 42 from the center positions C ′ and D ′ of the inlet cross sections of the vortex chambers 4a ′ and 4b ′. The air supply ports 5a and 5b 'are eccentric so as to be eccentric to the side. In FIG. 6, only the first air supply port 5a ′ and the second air supply port 5b ′ are configured to be eccentric. However, it is needless to say that the third air supply port 5c ′ may also be eccentric. .

Further, in the above-described air supply manifold 1 ′, when the first air supply port 5a ′ and the second air supply port 5b ′ are decentered, the air supply collects through the air supply inlet 21 ′ and the vortex chambers 4a ′ and 4b ′. It is preferable that the eccentricity of the air supply ports 5a ′ and 5b ′ is set in inverse proportion to the distance from a line (not shown) orthogonal to the axis of the tube 2 ′.
In this way, by adjusting the amount of eccentricity according to the distance between the air supply inlet 21 ′ and the line passing through the vortex chambers 4a ′ and 4b ′ and perpendicular to the axis of the air supply collecting pipe 2 ′, a plurality of vortex chambers are obtained. The flow velocity distribution at the vortex chamber inlet cross section at 4a ′ and 4b ′ can be made substantially uniform with high accuracy, and the swirl variation in each cylinder can be suppressed.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to this, In the range which does not deviate from the summary of this invention, you may combine the above-mentioned 1st Embodiment and 2nd Embodiment suitably. However, it goes without saying that various improvements and modifications may be made.

1, 1 'air supply manifold 2, 2' air supply collecting pipe 3, 3 'air supply introduction pipe 4, 4a to 4c, 4', 4a 'to 4c' vortex chamber 5, 5a to 5c, 5 ', 5a' -5c 'supply port 6, 6' supply valve 8 cylinder 21, 21 'supply inlet 41, 41' turning center 42, 42 'swirl turning start part 43a-43c, 43a'-43c' vortex chamber inlet cross section

Claims (7)

An air supply collecting pipe arranged along the longitudinal direction of a cylinder row in which a plurality of cylinders are arranged at equal intervals and a cylinder head side end of each cylinder are connected to form a swirl in the cylinder. An air supply manifold of an internal combustion engine comprising a plurality of vortex chambers and a plurality of air supply ports that connect the vortex chambers and the air supply collecting pipe, respectively.
Among the plurality of air supply ports, the air supply port where the swirl swirl start portion of the vortex chamber is located on the main flow generation start side of the air supply collecting pipe with respect to the swirl center of the vortex chamber is the supply port. An air supply manifold, wherein a central axis is arranged so as to be eccentric from a center position of an inlet cross section of the vortex chamber toward the main flow generation starting point. When there are two or more air supply ports in which the central axis of the air supply port is eccentric from the center of the inlet cross section of the vortex chamber to the main flow generation start side,
2. The air supply according to claim 1, wherein the one eccentric supply port has an eccentric amount larger than that of another supply port located farther from the main flow generation start point than the one supply port. Manifold. When there are two or more air supply ports in which the central axis of the air supply port is eccentric from the center of the inlet cross section of the vortex chamber to the main flow generation start side,
The eccentric amount of the air supply port is set in inverse proportion to the distance between the main flow generation starting point and a line passing through the swirling center of the vortex chamber and orthogonal to the air supply collecting pipe. Item 2. An air supply manifold according to Item 1.   Among the plurality of air supply ports, the air supply port in which the swirl swirl start portion of the vortex chamber is located on the opposite side of the swirl center of the swirl chamber from the main flow generation start point is a central axis of the air supply port 4. The air supply manifold according to claim 1, wherein the air supply manifold is arranged so as to be eccentric from a center position of an inlet cross section of the vortex chamber toward the main flow generation starting point. 5.   The air supply manifold according to any one of claims 1 to 4, wherein the main flow generation starting point is an air supply inlet of the air supply collecting pipe.   5. The main flow generation start point is a position at which supply air introduced from a supply inlet of the supply air collection pipe collides with a wall surface of the supply air collection pipe. Air supply manifold. An air supply manifold according to any one of claims 1 to 6,
An internal combustion engine comprising: a plurality of cylinders respectively connected to the plurality of vortex chambers of the air supply manifold.