CN110863932B

CN110863932B - Air intake manifold

Info

Publication number: CN110863932B
Application number: CN201910789156.5A
Authority: CN
Inventors: 小林勇人; 向井康晴
Original assignee: Keihin Corp
Current assignee: Hitachi Astemo Ltd
Priority date: 2018-08-28
Filing date: 2019-08-26
Publication date: 2021-08-24
Anticipated expiration: 2039-08-26
Also published as: JP2020033892A; JP6534766B1; CN110863932A

Abstract

The present invention relates to an intake manifold. In an intake manifold (10), an inlet portion (12) for air introduction is connected to one end in the width direction of a surge tank (14). The inlet portion (12) is inclined with respect to the width direction of the surge tank (14) so as to be directed toward a bottom wall (24) of the surge tank (14), the bottom wall (24) facing a connection point between the first to third branch pipes (16, 18, 20) and the surge tank (14). The bottom wall (24) of the surge tank (14) includes a first step portion (34) that faces the first branch pipe (16) closest to the inlet portion (12) and that serves as a separation portion that partially separates air introduced from the inlet portion (12).

Description

Air intake manifold

Technical Field

The present invention relates to an intake manifold for supplying intake air to a plurality of cylinder chambers of an internal combustion engine.

Background

A typical multi-cylinder engine mounted in an automobile or the like is provided with an intake manifold provided between an intake port of a cylinder head and a throttle valve that adjusts an intake air amount. Intake air drawn into the intake manifold is distributed to the intake ports via branch pipes.

As disclosed in, for example, japanese patent laid-open publication No. 2018-044518, such an intake manifold includes: an air inlet for introducing intake air; a buffer tank connected to the air inlet; and a plurality of branch pipes branched from the buffer tank. The branch pipes are arranged in parallel in the longitudinal direction of the surge tank and extend in a direction substantially orthogonal to the extending direction of the air inlet.

The intake air introduced from the air inlet is distributed from the surge tank to the branch pipes and supplied to the cylinder chambers of the internal combustion engine.

Disclosure of Invention

In the above intake manifold, an extending direction of an air inlet for introducing intake air is substantially orthogonal to an extending direction of the plurality of branch pipes. Since the intake air introduced into the surge tank from the air inlet flows in the longitudinal direction of the surge tank, the intake air tends to flow more easily into the branch pipe farthest from the air inlet and, conversely, less easily into the branch pipe closest to the air inlet.

As a result, the amount of intake air flowing in the branch pipes of the intake manifold varies, and it is difficult to evenly distribute the intake air to each cylinder chamber of the internal combustion engine.

A general object of the present invention is to provide an intake manifold capable of reducing unevenness in the amount of air supplied to a plurality of branch pipes.

According to one aspect of the present invention, an intake manifold includes: an inlet portion into which air is introduced; a buffer tank connected with the inlet portion; and a plurality of branch pipes arranged in parallel in a width direction of the surge tank and connected with the surge tank to branch and supply air to the internal combustion engine, wherein the inlet portion is connected with one end in the width direction of the surge tank. The inlet portion is inclined with respect to the width direction of the surge tank so as to be directed toward a wall portion of the surge tank, the wall portion facing a connection point between the plurality of branch pipes and the surge tank. The wall portion includes a separation portion that faces a branch pipe, which is disposed closest to the inlet portion, among the plurality of branch pipes, and that partially separates air introduced from the inlet portion.

According to the present invention, the surge tank constituting the intake manifold is connected with the inlet portion for air introduction at one end of the surge tank, the one end being located at the end in the width direction, and the inlet portion is inclined with respect to the width direction of the surge tank so as to be directed toward the wall portion of the surge tank, the wall portion facing the connection point between the plurality of branch pipes and the surge tank. Further, the wall portion of the buffer tank includes a separation portion provided at a position facing a branch pipe disposed closest to the inlet portion among the plurality of branch pipes to partially separate the air introduced from the inlet portion.

Therefore, the air introduced into the surge tank from the inlet portion is guided to the wall portion of the surge tank that faces the connection point of the plurality of branch pipes, and the air that hits the wall portion is favorably guided to the plurality of branch pipes. In addition, the introduced air is partially separated from the air flow by the separation portion and is guided to the branch pipe disposed closest to the inlet portion.

As a result, when air is introduced into the surge tank from the inlet portion, the air is actively guided to the branch pipe closest to the inlet portion, while the air flowing to the branch pipe farthest from the inlet portion in the width direction is reduced, as compared with the case where the air flows more easily into the branch pipe farthest from the inlet portion and less easily into the branch pipe near the inlet portion. Accordingly, the air is substantially uniformly distributed to the plurality of branch pipes arranged in parallel and connected to the surge tank, thereby reducing unevenness in the amount of air supplied.

The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative examples.

Drawings

FIG. 1 is a cross-sectional view of an entire intake manifold according to one embodiment of the present invention;

FIG. 2 is a sectional view taken along line II-II in FIG. 1; and is

Fig. 3 is a sectional view taken along line III-III in fig. 1.

Detailed Description

The intake manifold 10 is a manifold capable of supplying intake air to cylinder chambers in a three-cylinder internal combustion engine. As shown in fig. 1 to 3, the intake manifold 10 is injection-molded in one piece using, for example, a resin material, and includes: a tubular inlet portion 12 connected to a throttle valve (not shown); a buffer tank 14 temporarily storing air introduced from the inlet portion 12; and a plurality of first, second, and

third branch pipes

16, 18, and 20 connected with a downstream portion of the surge tank 14 to guide air to respective cylinder chambers of an internal combustion engine (not shown).

The surge tank 14 is an elongated tank having a predetermined volume, which extends in the width direction (the direction of arrows a1 and a 2) of the intake manifold 10. One width end of the surge tank 14 is connected to the inlet portion 12. As shown in fig. 2, the surge tank 14 includes an upper wall 22 and a bottom wall (wall portion) 24, the upper wall 22 and the bottom wall (wall portion) 24 being disposed in parallel and separated from each other by a predetermined distance in the thickness direction (the direction of arrow B). The first, second and

third branch tubes

16, 18, 20 are connected to the surge tank 14 at a location between the upper wall 22 and the bottom wall 24.

The inlet portion 12 has a tubular shape in which an inlet passage 26 is formed, and the inlet portion 12 protrudes by a predetermined length in the width direction. One end of the inlet portion 12 is connected to one width end of the surge tank 14, and the other end includes a flange portion 28 connected to a throttle valve (not shown). The inlet passage 26 passes through the center of the flange portion 28.

As shown in fig. 1, the inlet portion 12 extending from one end to the other end is inclined at a predetermined angle toward the first branch pipe 16, the second branch pipe 18, and the third branch pipe 20 with respect to the width direction (the direction of arrows a1 and a 2) of the surge tank 14. Also, as shown in fig. 2, the inlet portion 12 is inclined toward the upper wall 22 (the direction of the arrow B1) at a predetermined angle with respect to the thickness direction (the direction of the arrow B) orthogonal to the width direction. That is, the inlet portion 12 is connected to one width end of the surge tank 14 to be inclined in a three-dimensional manner.

As shown in fig. 2, the inclination angle of the inlet portion 12 is set such that, when the center line L of the inlet passage 26 is elongated toward the surge tank 14, the center line L intersects the bottom wall 24 at a point near the middle portion (facing the second branch pipe 18) in the width direction of the surge tank 14. This causes the air supplied to the surge tank 14 via the inlet portion 12 to be guided toward the middle portion of the surge tank 14 in the width direction.

As shown in fig. 1, the inlet portion 12 has a first port 30 for recirculating a part of exhaust gas (EGR gas) discharged from an internal combustion engine (not shown) to an intake system, and a second port 32 for recirculating purge gas leaking from a combustion chamber of the internal combustion engine to the intake system. The inlet passage 26 and the exterior of the inlet portion 12 communicate with each other via a first port 30 and a second port 32. The first port 30 and the second port 32 are connected to a pipe (not shown) so that the EGR gas and the purge gas are supplied to the inlet passage 26 via the first port 30 and the second port 32, respectively.

As shown in fig. 3, the inlet portion 12 is provided in the surge tank 14 and the protruding regions of the first branch pipe 16, the second branch pipe 18, and the third branch pipe 20 when viewed in the width direction of the intake manifold 10 to reduce the size of the intake manifold 10.

As shown in fig. 2, the first step portion (separation portion) 34 is formed at one width end of the surge tank 14 at a position close to the downstream opening 26a of the inlet channel 26 and on the bottom wall 24 side (in the direction of the arrow B2) with respect to a virtual line L1, which is an inner peripheral surface of the inlet channel 26 that is elongated toward the surge tank 14 in the extending direction of the inlet channel 26.

The first step portion 34 is molded integrally with the surge tank 14, and is recessed by a predetermined depth in the thickness direction (the direction of arrow B2), for example, with respect to a virtual line L1 extending from the inlet passage 26. The first step portion 34 includes a bottom portion 36 and a connecting portion 38, the bottom portion 36 being substantially flush with the bottom wall 24 of the surge tank 14, the connecting portion 38 being connected to the downstream opening 26a of the inlet passage 26 and gently inclined to the bottom portion 36.

The connection point between the bottom 36 and the connection portion 38 of the first step portion 34 has an angular cross-section.

That is, at one width end of the surge tank 14, the inlet passage 26 is connected with the bottom wall 24 of the surge tank 14 unevenly in the extending direction of the inlet passage 26, but the connection point is a step in the thickness direction of the surge tank 14.

A second step portion (separation portion) 40 is formed between the first branch pipe 16 (described below) and the downstream opening 26a of the inlet passage 26 at one width end of the surge tank 14, and the second step portion (separation portion) 40 is recessed toward the inlet portion 12 (the direction of arrow a 1) by a predetermined depth in the width direction. That is, the side wall 42 is formed as a step at one end in the width direction (the direction of the arrow a 1) of the surge tank 14.

As shown in fig. 1 to 3, the first branch pipe 16, the second branch pipe 18, and the third branch pipe 20 are arranged in parallel in the width direction (the direction of arrows a1 and a 2) of the surge tank 14. The upstream end of the branch pipe (connection point) is connected to the side wall 42 of the surge tank 14 such that the opening faces the bottom wall 24, and the downstream end is connected to each cylinder chamber of the internal combustion engine (not shown). As shown in fig. 1, the first branch pipe 16 is connected to the surge tank 14 at one width end side (i.e., at the inlet portion 12 side) (in the direction of arrow a 1), the second branch pipe 18 is connected to the surge tank 14 at an intermediate portion in the width direction, and the third branch pipe 20 is connected to the surge tank 14 at the other width end side (in the direction of arrow a 2).

The intake manifold 10 according to the present embodiment of the invention is basically constructed as described above. Next, the operation and advantageous effects thereof will be described.

First, air whose flow rate is regulated by a throttle valve (not shown) is supplied to the inlet passage 26 of the inlet portion 12 of the intake manifold 10 shown in fig. 1, and flows into the surge tank 14 side along the inlet passage 26.

The air flowing along the inlet passage 26 is introduced into the surge tank 14 in a direction inclined with respect to the surge tank 14, and flows in the width direction within the surge tank 14 to be distributed to the first branch pipe 16, the second branch pipe 18, and the third branch pipe 20. The air supplied to the first branch pipe 16, the second branch pipe 18, and the third branch pipe 20 is supplied to the cylinder chamber of the internal combustion engine in sequence.

Generally, in a structure similar to the intake manifold 10 according to the present embodiment in which the inlet portion 12 for air introduction has an opening in the width direction (the direction of the arrow a 1) of the surge tank 14 and is connected at a position near the first branch pipe 16, the air supplied from the inlet portion 12 flows more easily into the third branch pipe 20 that is farthest from the inlet portion 12 in the width direction, and therefore the amount of air supplied to the third branch pipe 20 increases, since the air easily flows in the order of the third branch pipe 20, the second branch pipe 18, and the first branch pipe 16 as the pipes are closer to the inlet portion 12 in the width direction, the amount of air supplied to the first branch pipe 16, the second branch pipe 18, and the third branch pipe 20 tends to decrease in this order.

In contrast, as shown in fig. 2, the inlet portion 12 is inclined so as to be directed toward the middle of the surge tank 14 in the width direction. Therefore, the air supplied via the inlet passage 26 proceeds toward the area near the middle portion in the width direction of the surge tank 14, hits the bottom wall 24 at the area near the middle portion in the width direction, and flows toward the second branch pipe 18. This increases the amount of air supplied to the second branch tube 18, compared to the case where air flows more easily into the third branch tube 20, thereby reducing the amount of air supplied to the third branch tube 20.

The air introduced from the inlet passage 26 into the surge tank 14 is partially separated from the airflow and is diverted toward the first step portion 34 by means of the first step portion 34 provided on the bottom wall 24 side, and the diverted portion of the air is advantageously guided to the first branch pipe 16 disposed most upstream to face the first step portion 34. At the same time, the air from the inlet channel 26 is also partially separated from the air flow and diverted towards the first branch pipe 16 by means of the second step portion 40 facing the downstream opening 26a provided for the side wall 42, and the diverted portion is advantageously guided to the first branch pipe 16.

In this way, the air introduced from the inlet portion 12 can be partially separated from the airflow by the first and

second step portions

34 and 40 inside the surge tank 14 and actively guided to the first and

second branch tubes

16 and 18, as compared with the case where the air flows less easily into the first and

second branch tubes

16 and 18 than into the third branch tube 20.

Since the inlet portion 12 is directed toward the middle portion in the width direction of the surge tank 14, which faces the second branch pipe 18, and the first and

second step portions

34 and 40 are provided at one width end of the surge tank 14, air is actively directed to the first and

second branch pipes

16 and 18, and thus air flowing to the third branch pipe 20 is reduced, as compared with the case where air flows more easily into the third branch pipe 20 and less easily into the first and

second branch pipes

16 and 18. Thus, the air is substantially evenly distributed to the first, second and

third branch pipes

16, 18, 20 and supplied to the internal combustion engine.

As described above, in the present embodiment, the inlet portion 12 (inlet passage 26) into which air is introduced from the outside is connected to one width end of the surge tank 14 constituting the intake manifold 10, and is inclined at a predetermined angle with respect to the width direction of the surge tank 14 such that the inlet passage 26 is directed to the area of the bottom wall 24 near the middle portion in the width direction of the surge tank 14. Further, the bottom wall 24 is provided with a first step portion 34 facing the first branch tube 16 closest to the inlet channel 26.

With this structure, the air introduced into the surge tank 14 via the inlet passage 26 of the inlet portion 12 flows toward and hits a region of the bottom wall 24 near the middle portion in the width direction of the surge tank 14, and the air hitting the bottom wall 24 is favorably guided to the second branch pipe 18 disposed at the middle in the width direction. In addition, the air supplied from the inlet passage 26 is partially separated from the air flow by the first step portion 34, and the separated portion of the air is advantageously guided to the first branch pipe 16 facing the first step portion 34.

Since the inlet portion 12 for air introduction is directed toward the middle portion of the surge tank 14 in the width direction and the first step portion 34 is provided at one width end of the surge tank 14, air is actively directed to the first branch pipe 16 and the second branch pipe 18, and thus air flowing toward the third branch pipe 20 is reduced, as compared with a case where air flows more easily into the third branch pipe 20 and less easily into the first branch pipe 16 and the second branch pipe 18. Therefore, the air is substantially uniformly distributed to the first branch pipe 16, the second branch pipe 18, and the third branch pipe 20, and the unevenness in the amount of supplied air is reduced.

Further, the side wall 42 of the surge tank 14 is provided with a second step portion 40, and this second step portion 40 is recessed in the width direction (the direction of arrow a 1) at a position facing the downstream opening 26a of the inlet passage 26. This allows the air introduced into the surge tank 14 from the inlet passage 26 to be partially separated from the air flow and to be directed to the adjacent first branch pipe 16. Therefore, providing the second step portion 40 in addition to the first step portion 34 provided for the bottom wall 24 of the surge tank 14 enables more air to be guided to the first branch pipe 16, thereby further reducing the unevenness in the amount of air supplied to the first, second, and

third branch pipes

16, 18, and 20.

Further, in the case where the EGR gas and the purge gas are supplied to the inlet passage 26 via the first port 30 and the second port 32 provided for the inlet portion 12, the EGR gas and the purge gas are supplied to the surge tank 14 together with the air flowing into the inlet passage 26 and hit the bottom wall 24 of the surge tank 14, whereby the EGR gas and the purge gas can be favorably agitated to be favorably mixed with the air.

Further, the flow rate of the air separated from the air flow by the first step portion 34 and guided to the first branch pipe 16 and the flow rate of the air sent to the second branch pipe 18 and the third branch pipe 20 can be favorably adjusted in a balanced manner by appropriately adjusting the depth of the first step portion 34 in the thickness direction (the direction of the arrow B).

Also, the first and

second step portions

34 and 40 are recessed to have an angular cross-section with respect to the bottom wall 24 and the side wall 42 of the surge tank 14. This increases the effect of separating air from the airflow by means of the first and

second step portions

34, 40.

The intake manifold according to the invention is not particularly limited to the above-described embodiments, and of course, various structures may be adopted without departing from the scope of the invention.

Claims

1. An intake manifold (10) comprising:

an inlet portion (12) into which air is introduced;

a buffer tank (14) connected to the inlet portion; and

a plurality of branch pipes (16, 18, 20) arranged in parallel in a width direction of the surge tank and connected with the surge tank to branch and supply air to an internal combustion engine,

wherein the inlet portion is connected to one end of the buffer tank in the width direction,

wherein:

the inlet portion is inclined with respect to the width direction of the surge tank so as to be directed toward a wall portion (24) of the surge tank, the wall portion facing a connection point between the plurality of branch pipes and the surge tank; and is

The wall portion includes a separation portion (34) that faces a branch pipe (16) that is disposed closest to the inlet portion among the plurality of branch pipes and partially separates air introduced from the inlet portion,

the inlet portion is formed obliquely such that a center line of an inlet passage formed inside the inlet portion is directed to a wall portion at a center in a width direction of the surge tank, and the separation portion is provided at a position closer to the wall portion side than a virtual line extending to the surge tank along an inner peripheral surface closer to the wall portion side of the inlet passage,

the inlet portion is formed with a port that supplies gas from the internal combustion engine into an inlet passage.

2. The intake manifold according to claim 1, wherein the separation portion is in the form of a step recessed in the wall portion of the surge tank in a direction in which the inlet portion is inclined.

3. An intake manifold according to claim 1 or 2, wherein the split portion has an angular cross-section.

4. The intake manifold according to claim 1, wherein the surge tank includes another divided portion (40) that is recessed in the width direction and faces the branch pipe disposed closest to the inlet portion.