JPH05187235A - Air intake device for engine - Google Patents

Abstract

PURPOSE:To improve a resonance effect by coupling an upper stream course to a common suction passage in the middle of an air intake passage, providing a manifold having its volume increased, arranging a branch air intake passage to supply air to each cylinder, further branching a second branch air intake passage having a first branch air intake passage, through which the branch air intake passage is coupled to an independent air intake passage, and an opening/closing valve, and re-joining together the branch air intake passages downstream. CONSTITUTION:A manifold 11 having its volume increased and the upper stream side of which is connected to a common air intake passage 12 is formed in an air intake passage 10. The manifold 11 is branched into branch passages 17A and 17B, which are used for a right bank 3A and a left bank 3B, respectively. Each of the branch passages 17A and 17B is branched into a first branch air intake passage 29 to which independent air intake passages 20 and 21 for absorbing air therethrough are connected and a second branch air intake passage 30 having an opening/closing valve 31. The first and second branch air intake passages 29 and 30 are intercommunicated with each other, downstream.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Japanese Patent Laid-Open Publication No. Sho 6-1994
As can be seen in JP-A-2-159728, an independent intake passage communicating with an intake port of each cylinder is partitioned into a first independent intake passage and a second independent intake passage, and an opening / closing valve is provided in the second independent intake passage. It is known that the opening / closing valve is closed to narrow the passage area of the independent intake passage to increase the flow velocity of intake air in the low engine speed region. Further, in recent engines, many have been designed to improve the volumetric efficiency, that is, the torque by the dynamic effect of intake air (Japanese Patent Laid-Open No. 2-1196).
19).

By the way, in an engine provided with the above-mentioned intake device, that is, in an engine in which the passage area of the independent intake passage is narrowed by closing the opening / closing valve provided in the independent intake passage, the independent intake passage of each cylinder is In an operating state in which the passage area is narrowed, more specifically, in the low rotation region in which the on-off valve is closed, at the same time, resonance supercharging (this resonance supercharging is one of the intake dynamic effects). If you try to use), there are the following problems.

[0004]

The upstream side intake passage of the independent intake passage has a large passage area in consideration of the case where the passage area of the independent intake passage is expanded (the opening / closing valve is opened). It is usually a passage. Therefore, the diameter of the upstream passage of the independent intake passage becomes too large as compared with the first independent intake passage, and the inlet opening of the first independent intake passage acts as a volume expansion portion, so that the resonance wave is generated. There is a problem that it is difficult to obtain a large resonance effect due to damping at the inlet opening of the first independent intake passage.

Therefore, an object of the present invention is to divide the independent intake passage communicating with the intake port of each cylinder into a first independent intake passage and a second independent intake passage, and to the second independent intake passage, An opening / closing valve that opens and closes the second independent intake passage is provided, and the opening / closing valve is closed on the premise of the intake system of the engine in which the passage area of the independent intake passage is narrowed by closing the opening / closing valve. The purpose of the present invention is to provide an intake system for an engine that achieves a large resonance effect.

[0006]

In order to achieve the above technical object, the first invention of the present invention has the following configuration. That is,

A collecting portion provided in the middle of the intake passage, as a first volume expanding portion, extending from the collecting portion to the upstream side, and a common intake passage for all cylinders, and branching from the collecting portion to extend to the downstream side. , A plurality of branch intake passages for supplying intake air to each cylinder group with equal intervals of intake air, wherein the branch intake passage is divided into a first branch intake passage and a second branch intake passage, At the 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 passage of each cylinder group, A second opening / closing valve for opening / closing the second branch intake passage is provided in the branch intake passage.

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

The collecting portion provided in the middle of the intake passage, the collecting portion as the first volume expanding portion, the common intake passage extending from the collecting portion to the upstream side for all cylinders, and the cylinders in each cylinder group in which the intake air is at equal intervals A first merging portion where the upstream ends of the first independent intake passages merge, and a second merging portion where the upstream ends of the second independent intake passages in each cylinder group where the intake air is evenly spaced merge. The second merging portion is in direct communication with the collecting portion, and the first merging portion is in communication with the collecting portion via a branch intake passage.

[0010]

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

Further, if the resonance effect is to be obtained at the same engine speed as in the conventional case, the resonance system has a narrow passage diameter, so that the passage for obtaining the natural frequency of the same air column is obtained. The required length (the total path length of the independent intake passage and the branch intake passage) can be shortened, 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 (F) of the inlet of the second independent intake passage.
s) and the average passage area (F) of the first branch intake passage,
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 slightly larger than Fp so as not to increase the intake resistance.

According to the second aspect of the invention, when the on-off valve provided in the independent intake passage is closed, intake is performed through the branch intake passage, while when the on-off valve is opened, the above 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 branch valve is opened, and the branch intake passage may be determined in consideration of only when the branch valve is closed. That is, is the passage area of the branch intake passage necessarily equal to the passage area of the first independent intake passage,
Alternatively, it suffices to have a slightly larger passage area. Therefore, also in the second invention, the first
It is possible to obtain the same effects as the invention.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1 denotes an engine body of an otto type. The engine body 1 is a bank 3A on the left and right on which three cylinders 2 whose ignition orders are not adjacent to each other are arranged.
3B is a V-type 6-cylinder engine in which V-types are arranged to each other. That is, this V-type 6-cylinder engine 1
In the above, the three cylinders 2 existing in one bank 3A are inhaled at equal intervals, and the three cylinders 2 existing in the other bank 3B are inhaled at equal intervals.

The engine body 1 has two intake ports 4, 5 and two exhaust ports 6, 7 in 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 main body 1 is a four-valve engine having 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. The intake air is supplied to the collecting portion 11 from one common intake passage 12, and the common intake passage 12 is supplied to the air cleaner (not shown) in order from the upstream side to the downstream side. , The compressor 13a of the exhaust turbocharger 13, the intercharger 14, the 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 for the right bank 3A, and the left branch intake passage 1
7B is for left bank 3B.

That is, the right branch intake passage 17A communicates 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 are provided.
The independent intake passage 8 generically referred to as B will be described below.

Each independent intake passage 8 is partitioned by a partition wall 19 into a first independent intake passage 20 and a second independent intake passage 21, and the first independent intake passage 20 communicates with the first intake port 4. The second independent intake passage 21 is communicated with the second intake port 5, and the second independent intake passage 21 is provided with, for example, a shutter valve 22 which is opened at high engine speed and closed at low engine 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.
, And electromagnetic actuators 24A and 24B are coupled to one ends of the common shafts 23A and 23B. Since such a shutter valve 22 is conventionally known, its description is omitted. In the figure, the code 2
5 is a fuel injection valve.

The left and right branch intake passages 17A and 17B are communicated with each other on the side opposite to the collecting portion 11 by a communication passage 26 serving as a volume expanding portion, 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
The effective passage length of 7 is shorter than the effective passage length of the branch intake passage 17 extending from the collecting portion 11 to each cylinder 2.

Further, the left and right branch intake passages 17A, 17B
Is partitioned into a first branch intake passage 29 located on the side of each bank 3A or 3B and a second branch intake passage 30 located on the center side of the bank by a partition wall 28 that extends almost fully in the longitudinal direction thereof. The independent intake passage 8 is communicated with the first branch intake passage 29, while the second branch intake passage 30 is provided with a second switching valve 31 which is an on-off valve.

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

Fp + Fs ≧ F ≧ Fp

The opening areas Fp and Fs mean the areas of the inlet ends of the first or second independent intake passages 20 and 21, and the inlet ends of these independent intake passages 20 and 21 (rapid R portions). 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 on the downstream side of the merged portion. The turbine 13b is connected to the compressor 13 via a shaft 13c. The turbine 13b is driven by the exhaust energy, and this rotation is caused by the compressor 13a.
To be supercharged.

In the exhaust passage 35, the turbine 13 is provided.
A bypass passage 36 for bypassing b is provided,
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, whereby the maximum boost pressure is regulated.

A control unit U is provided for switching the first switching valve 27 and the like in accordance with the engine speed.
The control unit U has a sensor 4 for detecting the engine speed.
A signal from 0 is input, and 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. The closed region of the shutter valve 22 (the second independent intake passage 21
(Closed) In this region, intake is performed using the first independent intake passage 20. That is, by closing the shutter valve 22, the passage area of the independent intake passage 8 is narrowed.

On the premise of the above, in the low speed region I in this region, both the first and second switching valves 27 and 31 are closed. That is, the branch intake passage 17 has its passage area reduced by closing the second switching valve 31. Therefore, each cylinder 2 has an independent intake passage 8 (first independent intake passage 20) whose passage area is narrowed.
And the branch intake passage 17 (first
It is communicated with the collecting portion 11 as the first volume expanding portion via the branch intake passage 29). And this first
Since 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 as described above, the resonance wave does not attenuate and passes through a long passage length. As a result, it is transmitted to the collecting portion 11, and a large resonance effect can be obtained in the low rotation range.

Further, in the high rotation range 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.
Through the branch intake passage 17 (first branch intake passage 29) having a shorter effective passage length as a whole, it is communicated with the communication passage 26 as the second volume expanding portion. Therefore, the resonance wave is propagated to the communication portion 26 through the short passage length, and a large resonance effect can be obtained in the high rotation range in the area.

Opening area of the shutter valve 22 (second independent intake air)
In the low speed range III in the region, the first switching valve 27 is opened and the second switching valve 31 is closed in the low speed region III in the region. On the other hand, in the high speed region IV in this region, both the first switching valve 27 and the second switching valve 31 are opened. As a result, in the intake passage 10, branch intake passages 17A and 17B, and a collecting portion 11 that connects the upstream ends of these passages 17A and 17B to each other,
A loop-shaped intake system is formed by the communication passage 26 that connects the downstream end of the passage 17A and the downstream end of the passage 17B to each other. And, this loop-shaped intake system 17A,
A resonance effect will be obtained by 17B, 11, and 26.

Second Embodiment FIG. 3 shows a second embodiment . In the description of this embodiment, the same elements as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted. Is omitted, and the characteristic part 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 passages.

First, the second independent intake passage 21 will be described. The inlet openings of the second independent intake passages 21 of each bank 3A or 3B are merged, and the merged portion 45 is formed.
The upstream side of is directly communicated with the collecting portion 11.

On the other hand, the first independent intake passage 20 will be described. The inlet openings of the first independent intake passages 20 of each bank 3A or 3B are joined together, and the joining portion 46 is joined.
Is communicated with 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 a direction away from the gathering portion 11, then reverses downward by approximately 180 degrees and approaches the vicinity of the gathering portion 11 before reaching the joining portion 46. It is shaped to communicate.

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 through the communication passage 2 at the above-mentioned 180-degree inverted position.
6, the first switching valve 2 is connected to the communication passage 26.
7 are provided. In the present embodiment, when the shutter valve 22 and the first switching valve 27 are both closed,
A resonance system is formed by the independent intake passage 8 (first independent intake passage 20) having a narrowed passage area and the elongated first branched intake passage 29.

When the shutter valve 22 is closed and the first switching valve 27 is opened, the length dimension of the resonance system having the communication passage 26 as the volume expanding portion, that is, the first branch intake passage 29 is substantially the same. A half resonance system will be formed.

The first switching valve 2 in the second embodiment
An example of opening / closing control of No. 7 is shown in FIG.

Although not shown in the drawing, a second communication passage is provided to connect the merging portion 46 of the first independent intake passage 20 and the merging portion 45 of the second independent intake passage 21 to each other. An on-off valve may be provided in the passage and the on-off valve may be opened at high engine speed.

While the embodiment of the present invention has been described above by taking a six-cylinder engine having three cylinders as one group, the present invention is not limited to one having three cylinders as one group. 8
In addition to the cylinder engine and the in-line four-cylinder, the intake system may be configured by grouping two cylinders or four cylinders with equal intake intervals.

[0043]

As is apparent from the above description, according to the present invention, 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. If the resonance effect is to be obtained when the engine speed is the same as the conventional one, the intake device can be made compact.

[Brief description of drawings]

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

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

FIG. 3 is a development 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.

[Simple explanation 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 Collecting Part 12 Common Intake Passage 17 Branch Intake Passage 19 Partition Wall 20 1st Independent Intake Passage 21 2nd Independent Intake Passage 22 Shutter valve (open / close valve) 26 Communication passage 27 First switching valve (opening / closing valve for opening / closing communication passage) 29 First branch intake passage 30 Second branch intake passage 31 Second switching valve (Opening / closing second branch intake passage) Opening / closing valve) 45 Confluence part (second independent intake passage) 46 Confluence part (first independent intake passage)

Claims (15)

[Claims] 1. An independent intake passage communicating with an intake port of each cylinder is partitioned 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. In an intake system for an engine, which is provided with a first opening / closing valve for opening and closing and narrows the passage area of the independent intake passage by closing the first opening / closing valve, a first opening / closing valve is provided in the middle of the intake passage, A converging part as an expanding part, a common intake passage extending from the converging part to the upstream side, and a common intake passage for all cylinders, and a branch extending from the converging part to the downstream side, and the intake air is supplied to each cylinder group at equal intervals. A plurality of branch intake passages, 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. Communication with the second branch intake passage The first branch intake passage communicates with the independent intake passage of each cylinder group, and the second branch intake passage is provided with a second opening / closing valve that opens and closes the second branch intake passage. , An engine intake device characterized by the above. 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 substantially completely in the extending direction.
An intake device for an engine, which is divided into a branch intake passage, and the first branch intake passage and the second branch intake passage are communicated with each other at a downstream end of the branch intake passage. 3. The engine according to claim 2, wherein one bank and the other bank of the engine are V
V-type engine arranged in a mold, one cylinder group having intakes arranged at equal intervals is arranged in the one bank, and another cylinder group having intakes arranged at equal intervals is arranged in the other bank. Two branch intake passages are provided, the first branch intake passage in one branch intake passage communicates with the one cylinder group, and the second branch intake passage in another branch intake passage includes the other branch intake passage. An air intake device for an engine, which is in communication with a cylinder group of. 4. The engine according to claim 3, wherein the two branch intake passages are arranged in a V bank central space sandwiched between the one bank and the other bank, and these two branch intake passages are provided in the engine. An intake system for an engine, wherein the intake system extends in the output shaft direction. 5. The area (Fp) of an inlet opening of the first independent intake passage according to claim 1,
An area (Fs) of the inlet opening of the second independent intake passage,
The intake device for an engine, wherein the average passage area (F) of the first branch intake passage has a relationship of Fp + Fs ≧ F ≧ Fp. 6. The branch intake passage according to claim 1, wherein the branch intake passages are communicated with each other at their downstream ends via a communication passage serving as a second volume expanding portion, and the communication passage is opened and closed with respect to the communication passage. An intake system for an engine, comprising a third opening / closing valve. 7. An independent intake passage communicating with an intake port of each cylinder is partitioned 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. In an intake device for an engine, which is provided with an on-off valve for opening and closing and narrows the passage area of the independent intake passage by closing the on-off valve, it is provided in the middle of the intake passage and serves as a first volume expanding portion. A converging part, a common intake passage extending from the converging part to the upstream side for all cylinders, and a first converging part in which the upstream ends of the first independent intake passages in each cylinder group in which the intakes are equally spaced, A second merging portion, in which the upstream ends of the second independent intake passages in each cylinder group in which intake air is evenly spaced, merges, the second merging portion is directly communicated with the collecting portion, and The merging part is connected to the collecting part via the branch intake passage. An intake device for an engine, which is in communication with each other. 8. The engine according to claim 7, wherein one bank and the other bank are mutually V
V-type engine arranged in a mold, one cylinder group having intakes arranged at equal intervals is arranged in the one bank, and another cylinder group having intakes arranged at equal intervals is arranged in the other bank. Two branch intake passages are provided, and one branch intake passage has a downstream end communicated with the first merging portion in the one cylinder group and an upstream end communicated with the collecting portion, and the like. The intake device for an engine, wherein the downstream end of the branch intake passage is communicated with the first merging portion in the other cylinder group, and the 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 system for an engine according to claim 9, wherein the two branched intake passages extend in the engine output shaft direction. 11. The two branch intake passages according to claim 10, wherein the two branch intake passages extend in a direction away from the collecting portion and are then inverted by about 180 degrees so as to communicate with the first merging portion in the vicinity of the collecting portion. The intake system for the engine is characterized by the fact that 12. The area (Fp) of an inlet opening of the first independent intake passage according to claim 7,
An area (Fs) of the inlet opening of the second independent intake passage,
An intake device for an engine, wherein the 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 passages in another cylinder group form a communication passage as a second volume expansion part in the middle thereof. An intake device for an engine, characterized in that a second opening / closing valve, which is communicated via the second opening / closing valve for opening / closing the communication passage, is provided in 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 part in the middle thereof. A second opening / closing valve that is communicated via the opening / closing valve and that opens / closes the communication passage, and the communication passage is arranged at an inverted portion of the branch intake passage. The intake system of the engine. 15. The method according to claim 7, wherein the first merging portion and the second merging portion are communicated with each other through a second communication passage, and the second communication passage is opened and closed with the second communication passage. An intake system for an engine, comprising a third opening / closing valve.