JP2583529B2 - Engine intake system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an intake device for a multi-cylinder engine,
The present invention relates to a system in which intake air supercharging is performed by causing a resonance phenomenon of intake air in an intake system.

(Prior Art) Conventionally, there have been known various ones in which the filling efficiency is increased by a dynamic effect of intake air taken into a combustion chamber in a cylinder of an engine to increase the output torque of the engine. As one example, in Japanese Patent Publication No. Sho 60-14169, for example, an intake passage in a multi-cylinder engine is connected to cylinder groups in which cylinders in which the intake order (ignition order) is not continuous are the same. Divided into two intake passages, each of which is constituted by an enlarged chamber to which a branch section upstream end of the intake manifold is connected, and a resonance intake passage connected to the enlarged chamber,
The upstream end of the resonance intake passage is communicated with the upstream collecting chamber,
A switching device for switching the two intake passages to a communication state or a communication cutoff state is provided in the enlarged chamber, and when the communication between the intake passages is cut off by the switching device, a negative pressure wave generated in the intake stroke of each cylinder is provided. Is reflected in the upstream collecting chamber and inverted to a positive pressure wave, and the inverted positive pressure wave exerts an inertial supercharging effect of intake air in a relatively low rotation range, while allowing each intake passage to communicate with each other. In such a case, the reverse reflection position of the intake pressure wave is brought closer to the intake port, the natural frequency of the intake pressure vibration is increased, and an inertia supercharging effect is obtained in a high-speed rotation range.

Japanese Patent Application Laid-Open No. 59-565 discloses that when the intake air of a V-type engine is supercharged due to its resonance phenomenon, as a specific structure, an outer wall having a space inside is provided between left and right banks of the engine. A plenum-type intake manifold comprising a plurality of ram pipe-type intake pipes arranged to extend annularly along the outer wall in the space of the outer wall in a substantially vertical plane and having a downstream end communicating with each intake port. By placing
It is disclosed that the intake air is supercharged by a compact intake manifold.

(Problems to be Solved by the Invention) By the way, in order to make the intake system of the engine compact, unlike the above-described conventional example, for example, each intake port of two cylinder groups in which cylinders in which the intake order is not continuous is the same group, It is connected to a common resonance annular intake passage without an expansion chamber, and this annular intake passage communicates with a portion communicating with the intake port of each cylinder of one cylinder group and an intake port of each cylinder of the other cylinder group. Each part is 2
The two-way communication path between the two cylinder groups is formed to be sufficiently larger than the length between the intake ports of adjacent cylinders of the same cylinder group. Thereby, the positive pressure pressure wave generated in the vicinity of the intake port at the end of the intake stroke of each cylinder of the cylinder group is caused to substantially travel around the resonance annular passage so as to act on the intake port of another cylinder of the same cylinder group, It is conceivable to effectively reduce the size of the intake air by eliminating the need for an expanded chamber while effectively exhibiting the dynamic effect of the intake air.

In such a case, for example, a plurality of cylinders of the engine are connected to a resonance intake passage having no expansion chamber, and an upstream end of the resonance intake passage is connected to a pressure reversing unit, so that intake of the intake air in the resonance intake passage is performed. The following advantages are obtained as compared with the case where the intake air is supercharged using the resonance phenomenon.

That is, in the latter case, the propagation state of the pressure wave in the resonance state of the intake air differs due to the variation in the distance from each cylinder to the pressure reversing section, and the intake charge amount differs between the cylinders. Along with the influence of the dynamic pressure of the intake air flowing into the intake passage, the amount of intake air charged in the most upstream cylinder near the pressure reversal section becomes larger than that in the downstream cylinder far from the intake supply passage, and therefore, The air-fuel ratio in the side cylinder is excessively leaned toward the lean side, and knocking may occur. In contrast,
In the former case, the positive pressure wave of the intake air generated in each cylinder of each cylinder group goes around the annular intake passage and acts on the other cylinders, so that the distribution of intake air to each cylinder in the resonance region is good. , Knocking can be suppressed.

However, on the other hand, compared to the latter case, in order to exhibit a good supercharging effect at the same engine speed,
It is necessary to set the length of the intake passage long. Therefore, especially when obtaining a supercharging effect up to the low-speed rotation range of the engine, the intake system becomes extremely large, which is contrary to the original purpose of making the intake system compact.

The present invention has been made in view of the above points, and an object of the present invention is to improve the structure of the above-described resonance intake passage to form a resonance annular intake passage so that a resonance passage having a long passage length is formed. An object of the present invention is to enable the annular intake passage to be formed by a compact intake system, thereby achieving both the compactness of the intake system of the engine and the suppression of occurrence of knocking due to uneven intake air-fuel ratio in the resonance region.

(Means for Solving the Problems) In order to achieve this object, a solution taken in the present invention is to divide the resonance intake passage into two along the length direction of the passage, and form the resonance intake passage formed by the division. By making the two passages communicate with each other at the end, one continuous annular intake passage for resonance is obtained.

Specifically, the present invention, as described above, a plurality of cylinders,
The cylinders are divided into two cylinder groups so that the intake sequence is not continuous and the intake strokes are equally spaced. Each cylinder group is provided with a resonance intake passage that is continuous, and resonance is tuned in the resonance intake passage. As an intake device for a supercharged engine, the resonance intake passage is divided into first and second intake passages extending along the length of the passage. Then, all the cylinders of the two cylinder groups are connected to the first intake passage so that intake air is supplied to each cylinder through the first intake passage.

Further, a communication path is provided at a downstream end portion of the first intake passage in the intake air flow direction, the communication passage communicating one end of the second intake passage.

(Operation) According to the above configuration, in the present invention, the resonance intake passage is divided into the first and second intake passages in the passage length direction, and the downstream end of the first intake passage in the intake passage direction. Since each of the portions is provided with a communication passage communicating with one end of the second intake passage, one continuous annular ring formed of the first and second intake passages and the communication passage is provided in the resonance intake passage. An intake passage is formed. During the operation of the engine, the intake air is supercharged in resonance in the one annular intake passage.

In this way, since the resonance intake passage is divided to form one long annular intake passage, the annular intake passage can be formed compact without increasing the size of the intake system.

Further, since the intake air is resonantly tuned by the annular intake passage, the distribution of the intake air to each cylinder is improved, and the occurrence of knocking of the engine can be suppressed.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows the overall structure of an intake system for an engine according to a first embodiment of the present invention, where 1 is a first to sixth units arranged in a V-shape.
In the fuel injection type V-type six-cylinder engine having the six cylinders 2a to 2f, the ignition order of the six cylinders 2a to 2f is set in the order of the first cylinder 2a to the sixth cylinder 2f according to the cylinder number. I have. The six cylinders 2a to 2f are three cylinders of the first, third and fifth cylinders 2a, 2c and 2e whose ignition order is not continuous, and three cylinders of the second, fourth and sixth cylinders 2b, 2d and 2f. Each of the three cylinders 2a, 2c, and 2e is formed in one bank 1a arranged in the V-shape of the engine 1 in order, and the other cylinder group of the other cylinder group is formed. The three cylinders 2b, 2d, 2f are sequentially formed in the other bank 1a.

Each of the cylinders 2a to 2f includes an intake port 3 and an exhaust port (not shown), and an intake passage 4 such as a surge tank is connected to each of the intake ports 3. This intake passage 4
Are composed of independent intake passages 5, 5,..., A resonance intake passage 6 and an intake supply passage 7. The resonance intake passage 6 includes a pair of communication passages 6a, 6a which are closed at a downstream end and extend linearly, and an upstream communication passage 6a which connects respective upstream ends of the communication passages 6a, 6a.
The upstream ends of three independent intake passages 5, 5,... Corresponding to the cylinders 2a, 2c, 2e (or 2b, 2d, 2f) of each cylinder group are connected to the communication passages 6a, 6a, respectively. ing.

Further, the downstream end of the intake supply passage 7 is connected to the central portion, that is, the upstream end of the upstream communication passage 6 b of the resonance intake passage 6, and the upstream end of the intake supply passage 7 is connected to the air cleaner 8. The air flow meter 9
Further, a throttle valve 10 is disposed downstream of the throttle valve.

A partition wall 11 is provided in the resonance intake passage 6. The partition wall 11 is connected from the vicinity of the connection to the first cylinder 2a located on the most downstream side of one of the cylinder groups in one of the communication passages 6a of the resonance intake passage 6 through the upstream communication passage 6b through the other communication passage. In 6a, it extends to the vicinity of the connection to the second cylinder 2b located on the most downstream side of the other cylinder group,
The partitioning wall 11 divides the resonance intake passage 6 into an outer first intake passage 12 and an inner second intake passage 13 extending along the length of the resonance intake passage 6. The upstream end of each independent intake passage 5 is connected to 12.

Further, at the downstream end of the partition wall 11, that is, in the vicinity of the connecting portion to the first and second cylinders 2a, 2b on the most downstream side of each cylinder group in both communication passages 6a, 6a of the resonance intake passage 6,
Communication passages 14, 14 are formed to connect both downstream ends of the first intake passage 12 in the intake air flow direction to corresponding ends of the second intake passage 13, respectively. Therefore, with this structure,
The first and second intake passages 1 are provided in the resonance intake passage 6.
One continuous annular intake passage 15 composed of 2,13 and two communication passages 14,14 is formed.

Therefore, in the above embodiment, the partition wall 11 is provided in the resonance intake passage 6, and the partition wall 11 causes the resonance intake passage 6 to extend in the length direction of the resonance first intake passage 12 and the inside of the first intake passage 12. Communication passages 14, 14 are formed at the downstream end of the partition wall 11 to communicate the ends of the first and second intake passages 12, 13. And the first and second intake passages 12, 13 and 2
Since one continuous annular intake passage 15 is formed by the two communication passages 14, 14, during operation of the engine 1, the intake air is resonated and supercharged in the one annular intake passage 15 formed above. You. That is, each cylinder 2a of the engine 1
A positive pressure wave of intake air generated at the end of the intake stroke of each of the cylinders 2a to 2f near the intake port 3 of 2f is applied to the first and second intake passages.
After propagating through the resonance annular intake passage 15 by propagating through the resonance intake passages 12 and 13, respectively, the intake air is in a resonance-tuned state in which it acts on the intake ports 3 of the other cylinders 2a to 2f of the same cylinder group. And the output torque of the engine 1 increases.

In that case, as described above, the inside of the resonance intake passage 6 is partitioned by the partition wall.
The first and second intake passages 12 and 13 are formed by dividing the first and second intake passages 12 and 13 by the communication passages 14 and 14. Since the intake passage 15 is formed, the size of the intake system is not increased, so that the resonance annular intake passage 15 can be formed with a compact intake system.

In addition, since the intake air is resonantly tuned by the annular intake passage 15, the distribution of the intake air to each of the cylinders 2a to 2f is improved, and the occurrence of knocking of the engine 1 can be suppressed.

FIG. 2 shows a second embodiment of the present invention (note that the same parts as those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted). In this case, one annular intake passage having a long length is formed.

That is, in this embodiment, each cylinder 2a to
The intake passage 4 'connected to the intake port 3 of 2f and having no volume expansion chamber such as a surge tank is provided with independent intake passages 5, 5,.
And the first annular intake passage 16 for resonance and the intake supply passage 7. The annular annular intake passage 16 for resonance includes an independent intake passage 5 for each of the cylinders 2a to 2f in the two cylinder groups.
5, two communication paths 16a, 16a connected to the
An upstream communication passage 16b which communicates with ends of the fifth and sixth cylinders 2e and 2f on the side of 16a and extends in one direction, and an intermediate portion to which a downstream end of the intake supply passage 7 is connected; Communication passage 16a, 1
A downstream communication passage 16c which communicates with the ends of the first and second cylinders 2a and 2b of 6a and extends in the other direction.

And each cylinder of the cylinder group that does not communicate in the intake order
In the vicinity of the intake ports 3 of the cylinders 2a to 2f, pressure oscillations of the intake air which become positive pressure at the end of the intake stroke of each of the cylinders 2a to 2f are generated, and the pressure waves of the pressure oscillations are transmitted to the upstream and downstream communication passages 16b, 16c After the first annular intake passage 16 is made to travel substantially once by propagating in two directions different from each other, the other cylinders in the same cylinder group
By acting on the intake ports 3a to 2f, the intake air is resonated and supercharged.

In the first annular intake passage 16, a partition wall 11 extending from near the downstream end of one communication passage 16a to near the downstream end of the other communication passage 16a via the upstream communication passage 16b is formed. First and second intake passages by wall 11
12, 13 are formed, and communication paths 14, 14 are formed at the downstream end portion of the partition wall 11, and by this structure,
First and second intake passages in the first resonance intake passage 16
A second resonance annular intake passage 17 is formed, which is constituted by 12, 13 and two communication passages 14, 14.

Further, a pair of shutter valves 18 each composed of a butterfly valve which opens and closes in synchronization with each other is provided near the connection end with the communication passages 16a, 16a in the downstream communication passage 16c in the first resonance annular intake passage 16. , 18 are provided. The opening and closing of these shutter valves 18 and 18 are controlled in accordance with the engine speed, and are adjusted so as to be closed when the engine speed is low and open when the engine speed is high.

Therefore, in this embodiment, in the low-speed rotation range of the engine 1, the shutter valves 18, 18 are closed and the first
The annular intake passage 16 for resonance is closed halfway. In this state, the structure is the same as that of the first embodiment, and the intake air is resonated in the second resonance annular intake passage 17 composed of the first and second intake passages 12 and 13 and the communication passages 14 and 14. Supercharged in tune.

On the other hand, in the high-speed rotation range of the engine 1, the shutter valves 18, 18 are opened to open the first annular intake passage 16. In this state, the intake air is supercharged in resonance with the opened first annular intake passage 16.

Therefore, in the case of this embodiment, in addition to the same effects as those of the first embodiment, the engine 1
There is an advantage that the intake air can be resonantly supercharged over a wide rotation range from a low rotation speed range to a high speed rotation range to increase the output torque.

It is needless to say that the present invention can be applied to engines other than the V-type six-cylinder as in the above embodiments.

(Effects of the Invention) As described above, according to the present invention, when a resonance intake passage is connected to a cylinder of an engine and intake air is supercharged by resonance tuning of intake air in the resonance intake passage,
The above-described resonance intake passage is divided into two along the passage length direction, and the two passages formed by the division are communicated with each other at a downstream end to form one continuous resonance annular intake passage. With this configuration, one long resonance annular intake passage can be formed compactly without increasing the size of the intake system, and the distribution characteristic of intake air to each cylinder can be improved by the resonance characteristics of intake air by the annular intake passage. In other words, the occurrence of knocking of the engine can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing the overall configuration of the first embodiment of the present invention, and FIG. 2 is a schematic plan view showing the overall configuration of the second embodiment. DESCRIPTION OF SYMBOLS 1 ... Engine, 2a-2f ... Cylinder, 6 ... Resonance intake passage, 11 ... Partition wall, 12 ... First intake passage, 13 ... Second
.., A communication passage, 15... A resonance annular intake passage, 16... A first resonance annular intake passage, 17... A second resonance annular intake passage.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-56-52522 (JP, A) JP-A-60-159828 (JP, U) JP-A-58-81318 (JP, U)

Claims (1)

(57) [Claims] A plurality of cylinders are divided into two cylinder groups such that the intake sequence is not continuous and the intake strokes are equally spaced, and a plurality of cylinders are provided with a resonance intake passage connected to each cylinder group. What is claimed is: 1. An intake system for an engine, wherein intake air is resonantly tuned and supercharged in a resonance intake passage, wherein the first and second two intake airs extend along the resonance intake passage in a length direction of the passage. All the cylinders of the two cylinder groups are connected to the first intake passage, and the first intake passage supplies intake air to each of the cylinders. An intake device for an engine, wherein a communication passage communicating with one end of the second intake passage is provided at a downstream end portion of the intake passage in an intake flow direction.