JP3115078B2 - Engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for an engine.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No.
As disclosed in JP-A-2-159728, an independent intake passage connected to the intake port of each cylinder is divided into a first independent intake passage and a second independent intake passage, and an open / close valve is provided in the second independent intake passage. It is known that the opening / closing valve is closed to reduce the passage area of the independent intake passage, thereby increasing the flow rate of intake air in a low engine speed region. Further, in recent engines, many of them are designed to improve the volumetric efficiency, that is, to increase the torque by a dynamic effect of intake air (JP-A-2-1196).
No. 19).

Incidentally, in an engine having the above-described intake device, that is, an engine in which the passage area of the independent intake passage is reduced by closing an on-off valve provided in the independent intake passage, the independent intake passage of each cylinder is provided. More specifically, in an operation state in which the passage area is reduced, more specifically, in the low rotation region where the on-off valve is closed, resonance supercharging is simultaneously performed. ) Has the following problems.

[0004]

The intake passage upstream of the independent intake passage has a large passage area in consideration of a case where the passage area of the independent intake passage is enlarged (the on-off valve is opened). Usually, it is a passage. For this reason, the diameter of the upstream passage of the independent intake passage is too large compared to that of the first independent intake passage, and the inlet opening of the first independent intake passage acts as a volume expanding portion, so that a resonance wave is generated. There is a problem in that attenuation occurs at the entrance opening of the first independent intake passage, and it is difficult to obtain a large resonance effect.

Accordingly, an object of the present invention is to separate an independent intake passage leading to an intake port of each cylinder into a first independent intake passage and a second independent intake passage, and the second independent intake passage includes An opening / closing valve for opening and closing the second independent intake passage is provided, and a region where the opening / closing valve is closed on the premise of an engine intake device in which the opening / closing valve is closed to reduce the passage area of the independent intake passage. It is an object of the present invention to provide an intake device for an engine which can obtain a large resonance effect.

[0006]

Means for Solving the Problems In order to achieve the above technical object, the first aspect of the present invention has the following configuration. That is,

[0009] A collecting portion provided in the middle of the intake passage, serving as a first volume expanding portion, extending upstream from the collecting portion, extending in common to all cylinders, and branching from the collecting portion and extending downstream. A plurality of branch intake passages for supplying intake air to each cylinder group in which intake air is equally spaced, wherein the branch intake passage is divided into a first branch intake passage and a second branch intake passage, At a downstream end of the intake passage, the first branch intake passage and the second branch intake passage communicate with each other, and the first branch intake passage communicates with the independent intake passages of the cylinder groups, and the second branch intake passage communicates with the second intake passage. The branch intake passage is provided with a second on-off valve for opening and closing the second branch intake passage.

[0008] The second aspect of the present invention has the following configuration. That is,

[0009] A collecting portion, which is provided in the middle of the intake passage, serves as a first volume expansion portion, extends upstream from the collecting portion, and has a common intake passage for all cylinders. A first junction where the upstream ends of the first independent intake passages are joined; and a second junction where the upstream ends of the second independent intake passages in each cylinder group where the intake air is equally spaced are joined. The second junction is directly connected to the junction, and the first junction is connected to the junction via a branch intake passage.

[0010]

According to the first aspect, the on-off valve provided in the independent intake passage and the second valve provided in the branch intake passage are provided.
By closing both the open / close valve, the passage area of the branch intake passage can be reduced in correspondence with the independent intake passage having a reduced passage area. Therefore, the resonance wave is propagated to the collecting portion through the first branch intake passage without being attenuated at the rear portion of the first independent intake passage at the entrance opening, and a large resonance effect can be obtained.

If the resonance effect is to be obtained at the same engine speed as in the prior art, the resonance system has a small passage diameter. The required length (the total length of the independent intake passage and the branch intake passage) can be reduced, and the intake device can be made compact.

Here, the area (Fp) of the inlet opening of the first independent intake passage and the area (Fp) of the inlet opening of the second independent intake passage are described.
s) and the average passage area (F) of the first branch intake passage are:
It is desirable that Fp + Fs ≧ F ≧ Fp. That is, if the above Fp and F are substantially the same, the resonance wave propagates sufficiently upstream. More preferably, F is preferably slightly larger than Fp so as not to increase the intake resistance.

According to the second aspect of the present invention, when the on-off valve provided in the independent intake passage is closed, air is taken in through the branch intake passage. On the other hand, when the on-off valve is opened, In addition to intake using the branch intake passage (first independent intake passage), intake is also performed directly from the collecting portion to the second independent intake passage.

Therefore, it is not necessary to consider the intake air when the on-off valve is opened, but to determine the passage area of the branch intake passage only when the on-off valve is closed. That is, the passage area of the branch intake passage is necessarily the same as the passage area of the first independent intake passage,
Alternatively, it is only necessary to have a slightly larger passage area. Therefore, in the second invention as well, the first
The same operation and effect as those of the invention can be obtained.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes an Otto type engine main body. The engine main body 1 includes left and right banks 3A in which three cylinders 2 not adjacent to each other in ignition order are arranged.
3B are V-type 6-cylinder engines arranged in a V-type with each other. That is, the V-type six-cylinder engine 1
In the above, three cylinders 2 present in one bank 3A take air at equal intervals, and three cylinders 2 present in another bank 3B take air at equal intervals.

The engine body 1 has two intake ports 4, 5 and two exhaust ports 6, 7 for each cylinder 2.
These ports 4 to 7 are opened and closed at a known timing in synchronization with the engine output shaft by two intake valves or two exhaust valves (not shown). That is, the engine body 1 is a four-valve engine provided with two intake valves and two exhaust valves for each cylinder 2.

The intake passage 10 for supplying intake air to each of the banks 3A and 3B has a collecting portion 11 as a first volume expanding portion in the middle thereof. Air is supplied to the collecting portion 11 from one common intake passage 12. The common intake passage 12 is provided with an air cleaner (not shown) in order from the upstream side to the downstream side. , Compressor 13a of exhaust turbo-type supercharger 13, intercooler 14, throttle valve 1
5 are provided.

In the intake passage 10, the collecting portion 1
1 is branched into two branch intake passages 17A and 17B, both extending in the engine output axis direction. The right branch intake passage 17A is used for the right bank 3A, and the left branch intake passage 1A is used for the right bank 3A.
7B is for the left bank 3B.

That is, the right branch intake passage 17A is communicated with each cylinder 2 of the right bank 3A via the independent intake passage 18A. Similarly, the left branch intake passage 17B communicates with each cylinder 2 of the left bank 3B via an independent intake passage 8B. The left and right independent intake passages 8A and 8B have the same configuration, and the left and right independent intake passages 8A and 8B have the same configuration.
The independent intake passage 8 collectively referred to as B will be described below.

Each independent intake passage 8 is divided into a first independent intake passage 20 and a second independent intake passage 21 by a partition wall 19, and the first independent intake passage 20 is communicated with the first intake port 4. The second independent intake passage 21 is communicated with the second intake port 5. The second independent intake passage 21 is provided with, for example, a shutter valve 22 which is opened when the engine is running at a high speed and closed when the engine is running at a low speed. . The shutter valves 22A arranged in the right bank 3A and the shutter valves 22B arranged in the left bank 3B respectively have common shafts 23A and 23B.
The electromagnetic actuators 24A and 24B are connected to one ends of the common shafts 23A and 23B. Since such a shutter valve 22 is conventionally known, further description is omitted. In the figure, reference numeral 2
5 is a fuel injection valve.

The left and right branch intake passages 17A and 17B are communicated with each other by a communication passage 26 as a volume expanding portion on the opposite side to the collecting portion 11, and the communication passage 26 has a first opening / closing valve. A switching valve 27 is provided.
Here, the branch intake passage 1 from the communication passage 26 to each cylinder 2
7 is shorter than the effective passage length of the branch intake passage 17 extending from the collecting portion 11 to each cylinder 2.

The left and right branch intake passages 17A, 17B
Are divided into a first branch intake passage 29 located on each bank 3A or 3B side and a second branch intake passage 30 located on the bank center side by a partition wall 28 extending almost completely in the longitudinal direction, respectively. The independent intake passage 8 communicates with the first branch intake passage 29, while a second switching valve 31 composed of an open / close valve is provided in the second branch intake passage 30.

Here, the area of the opening on the inlet side of the first independent intake passage 20 is represented by "Fp", and the area of the opening on the inlet side of the second independent intake passage 21 is represented by "Fs". The average of the effective passage area of the one-branch intake passage 29 is "F".
When expressed by, the following relationship is obtained.

Fp + Fs ≧ F ≧ Fp

The opening areas Fp, Fs mean the areas of the inlet ends of the first or second independent intake passages 20, 21, and the inlet ends of these independent intake passages 20, 21 (a sharp R portion). Is excluded.

On the other hand, the exhaust passages 35 connected to the exhaust ports 6 and 7 are finally merged into one, and the turbine 13b of the supercharger 13 is disposed downstream of the merged portion. The turbine 13b is connected to the compressor 13 via a shaft 13c. The turbine 13b is driven by exhaust energy, and this rotation is performed by the compressor 13a.
To be supercharged.

The exhaust passage 35 is provided with the turbine 13
b, a bypass passage 36 is provided to bypass b.
A waist gate valve 37 is provided for the bypass passage 36.
Are arranged. The waist gate valve 37 is opened and closed by a conventionally known diaphragm type actuator 38 so that the maximum supercharging pressure is regulated.

A control unit U is provided for switching the first switching valve 27 and the like according to the engine speed.
The control unit U has a sensor 4 for detecting the engine speed.
The control unit U controls the actuator 24 for the shutter valve 22, the actuator 42 for the first switching valve 27, and the actuator 43 for the second switching valve 31. A signal (open / close signal) is output.

An example of control of the first and second switching valves 27 and 31
Will be described with reference to FIG.Closed area of the shutter valve 22 (the second independent intake passage 21
Closed) In this region, intake air using the first independent intake passage 20 is provided.
Have been done. That is, closing the shutter valve 22
Therefore, the independent intake passage 8 has a reduced passage area.
It has become.

On the premise of the above, both the first and second switching valves 27 and 31 are closed in the low speed region I in the region. That is, the passage area of the branch intake passage 17 is reduced by closing the second switching valve 31. Therefore, each cylinder 2 has an independent intake passage 8 (first independent intake passage 20) having a reduced passage area.
And the branch intake passage 17 having a long effective passage length (first
Through the branch intake passage 29), it is communicated with the collecting portion 11 as the first volume expansion portion. And this first
As described above, the passage area F of the branch intake passage 29 is set to a value close to the area Fp of the inlet opening of the first independent intake passage 20, so that the resonance wave is not attenuated and passes through a long passage length. Therefore, a large resonance effect can be obtained in a low rotation range.

In the high rotation region II in the closed region of the shutter valve 22, the first switching valve 27 is opened and the second switching valve 31 is closed. That is, the communication passage 26 is opened, and each cylinder 2 is connected to the first independent intake passage 20.
As a whole, the communication passage 26 communicates with the communication passage 26 as the second volume expansion portion via the branch intake passage 17 (first branch intake passage 29) having a short effective passage length. Therefore, the resonance wave propagates to the communication portion 26 via a short passage length, and a large resonance effect can be obtained in a high rotation region in the region.

The opening area of the shutter valve 22 (second independent intake
(The passage 21 is open.) In the low speed region III in this region, the first switching valve 27 is opened and the second switching valve 31 is closed, as in the region II. On the other hand, in the high speed range IV in this region, the first switching valve 27 and the second switching valve 31 are both opened. Thus, the intake passage 10 includes branch intake passages 17A and 17B, and a collecting portion 11 that connects the upstream end of the passage 17A and the upstream end of the passage 17B to each other.
The communication path 26 that connects the downstream end of the passage 17A and the downstream end of the passage 17B to each other forms a loop-shaped intake system. And this loop-shaped intake system 17A,
17B, 11, and 26 provide a resonance effect.

Second Embodiment FIG. 3 shows a second embodiment . In the description of the present embodiment, the same elements as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted. Are omitted, and the features of the present embodiment will be described below.

Each of the first independent intake passages 20 and each of the second independent intake passages 21 of the right bank 3A or the left bank 3B are connected to the collecting portion 11 by independent paths.

First, the second independent intake passage 21 will be described. The entrance opening of each second independent intake passage 21 of each bank 3A or 3B is merged.
Is directly communicated with the collecting part 11.

On the other hand, the first independent intake passage 20 will be described. The first independent intake passage 20 of each bank 3A or 3B has its inlet opening merged.
Is connected to the collecting portion 11 via a first branch intake passage 29 extending in the engine output axis direction.

Here, the first branch intake passage 29 once extends in the direction away from the gathering portion 11, then is turned downward by almost 180 degrees and approaches the vicinity of the gathering portion 11, and then joins the merging portion 46. It has a shape that allows communication.

The first branch intake passage 29 for the right bank 3A and the second branch intake passage 29B for the left bank 3B are connected to each other by the communication passage
The first switching valve 2 is connected to the communication passage 26 through the communication passage 26.
7 are provided. In the present embodiment, when both the shutter valve 22 and the first switching valve 27 are closed,
A resonance system is formed by the independent intake passage 8 (first independent intake passage 20) having a reduced passage area and the elongated first branch intake passage 29.

When the shutter valve 22 is closed and the first switching valve 27 is opened, the length of the resonance system having the communication passage 26 as a volume expansion portion, that is, the length of the first branch intake passage 29 is reduced. A halved resonance system is formed.

The first switching valve 2 in the second embodiment
FIG. 4 shows an example of the opening / closing control of No. 7.

Although not shown, a second communication path is provided for connecting the junction 46 of the first independent intake passage 20 and the junction 45 of the second independent intake passage 21. An on-off valve may be provided in the passage, and the on-off valve may be opened at the time of high engine speed.

Although the embodiment of the present invention has been described by taking a six-cylinder engine having three cylinders as one group as an example, the present invention is not limited to one having three cylinders as one group. 8
For an in-cylinder engine and an in-line four-cylinder engine, the intake system may be configured with a group of two or four cylinders in which intake air is equally spaced.

[0043]

As is apparent from the above description, according to the present invention, in the operating region where the opening / closing valve provided in the second independent intake passage is closed to reduce the passage area of the independent intake passage connected to the intake port. , A large resonance effect can be obtained. Assuming that the resonance effect is obtained at the same engine rotation speed as in the related art, the intake device can be made compact.

[Brief description of the drawings]

FIG. 1 is a development view of an intake device according to a first embodiment.

FIG. 2 is a diagram showing an example of opening and closing control of first and second switching valves in the first embodiment.

FIG. 3 is an expanded view of an intake device according to a second embodiment.

FIG. 4 is a diagram showing an example of opening / closing control of a first switching valve in a second embodiment.

[Brief description of reference numerals]

DESCRIPTION OF SYMBOLS 1 Engine main body 2 Cylinder 3A One bank 3B Other bank 4, 5 Intake port 8 Independent intake passage 10 Intake passage 11 Assembly part 12 Common intake passage 17 Branch intake passage 19 Partition wall 20 First independent intake passage 21 Second independent intake passage Passage 22 Shutter valve (open / close valve) 26 Communication passage 27 First switching valve (open / close valve for opening / closing communication passage) 29 First branch intake passage 30 Second branch intake passage 31 Second switching valve (Open / close second branch intake passage) Opening / closing valve) 45 Merging part (second independent intake passage) 46 Merging part (first independent intake passage)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02B 27/02 F02M 35/104 F02M 35/108 F02M 35/116

Claims (15)

(57) [Claims] An independent intake passage connected to an intake port of each cylinder is divided into a first independent intake passage and a second independent intake passage, and the second independent intake passage is provided with the second independent intake passage. A first opening / closing valve that opens and closes, wherein the passage area of the independent intake passage is reduced by closing the first opening / closing valve; A collecting portion as an expanding portion; a common intake passage extending to the upstream side from the collecting portion, for all cylinders; and a branch extending from the collecting portion to the downstream side to supply intake air to each cylinder group in which intake air is equally spaced. A plurality of branch intake passages, wherein the branch intake passage is divided into a first branch intake passage and a second branch intake passage, and the first branch intake passage is provided at a downstream end of the branch intake passage. The second branch intake passage communicates with each other The first branch intake passage communicates with the independent intake passages of the cylinder groups, and the second branch intake passage is provided with a second on-off valve for opening and closing the second branch intake passage. An intake device for an engine, characterized in that: 2. The first branch intake passage and the second branch intake passage according to claim 1, wherein the branch intake passage is formed by a partition wall extending almost completely in a direction in which the branch intake passage extends.
An intake device for an engine, wherein the intake device is divided into a branch intake passage, and the first branch intake passage and the second branch intake passage communicate with each other at a downstream end of the branch intake passage. 3. The engine according to claim 2, wherein one bank and another bank are connected to each other by V
The engine is a V-type engine arranged in a mold, and one cylinder group in which intake air is equally spaced is arranged in the one bank, and another cylinder group in which intake air is equally spaced is arranged in the other bank. The two branch intake passages are provided, the first branch intake passage in one branch intake passage is communicated with the one cylinder group, and the second branch intake passage in another branch intake passage is connected to the other branch intake passage. An intake device for an engine, which is in communication with a group of cylinders. 4. The engine according to claim 3, wherein the two branch intake passages are arranged in a central space of a V bank sandwiched between the one bank and the other bank, and the two branch intake passages are provided for an engine. An intake device for an engine, which extends in a direction of an output shaft. 5. The method according to claim 1, wherein an area (Fp) of an inlet opening of the first independent intake passage is;
The area (Fs) of the entrance opening of the second independent intake passage;
An intake system for an engine, wherein an average passage area (F) of the first branch intake passage has a relationship of Fp + Fs ≧ F ≧ Fp. 6. The communication system according to claim 1, wherein the branch intake passages communicate with each other at a downstream end thereof through a communication passage as a second volume expanding portion, and the communication passage opens and closes the communication passage. An intake device for an engine, wherein a third on-off valve is provided. 7. An independent intake passage connected to an intake port of each cylinder is divided into a first independent intake passage and a second independent intake passage, and the second independent intake passage is provided with the second independent intake passage. An on-off valve for opening and closing is provided, and the opening area of the independent intake passage is reduced by closing the on-off valve. A collecting portion, a common intake passage extending to the upstream side from the collecting portion, for all cylinders, and a first merging portion where the upstream end of the first independent intake passage in each cylinder group in which intake air is equally spaced is merged; A second merging portion where the upstream end of the second independent intake passage in each cylinder group in which intake air is equally spaced is merged, wherein the second merging portion is directly communicated with the collecting portion; The junction is connected to the junction via the branch intake passage. An intake device for an engine, which is in communication with the engine. 8. The engine according to claim 7, wherein one bank and another bank are connected to each other by V
The engine is a V-type engine arranged in a mold, and one cylinder group in which intake air is equally spaced is arranged in the one bank, and another cylinder group in which intake air is equally spaced is arranged in the other bank. The two branch intake passages are provided, and one of the branch intake passages has a downstream end that communicates with the first junction in the one cylinder group, an upstream end that communicates with the collecting part, An intake device for an engine, wherein a downstream end of the branch intake passage is communicated with the first junction in the other cylinder group, and an upstream end is communicated with the collecting portion. 9. The intake air for an engine according to claim 8, wherein the two branch intake passages are arranged in a V-bank central space sandwiched between the one bank and the other bank. apparatus. 10. The intake device for an engine according to claim 9, wherein the two branch intake passages extend in an engine output axis direction. 11. The two-branch intake passage according to claim 10, wherein the two branch intake passages extend in a direction away from the gathering portion and are then turned substantially 180 degrees to communicate with the first junction near the gathering portion. An air intake system for an engine. 12. The air conditioner according to claim 7, wherein an area (Fp) of an inlet opening of the first independent intake passage is;
The area (Fs) of the entrance opening of the second independent intake passage;
An intake device for an engine, wherein an average passage area (F) of the branch intake passage has a relationship of Fp + Fs ≧ F ≧ Fp. 13. The branch intake passage according to claim 7, wherein the branch intake passage in one cylinder group and the branch intake passage in another cylinder group form a communication passage as a second volume expansion portion in the middle thereof. An intake device for an engine, wherein a second on-off valve is provided in the communication passage for opening and closing the communication passage. 14. The branch intake passage according to claim 11, wherein the branch intake passage in one cylinder group and the branch intake passages in another cylinder group form a communication passage as a second volume expansion section in the middle thereof. A second on-off valve that opens and closes the communication passage is disposed in the communication passage, and the communication passage is disposed at a location where the branch intake passage reverses. Engine intake system to be used. 15. The device according to claim 7, wherein the first junction and the second junction are communicated via a second communication path, and the second communication path opens and closes the second communication path. An intake device for an engine, wherein a third on-off valve is provided.