JPH03286128A - Air intake device for multiple cylinder engine - Google Patents

Abstract

PURPOSE:To increase an inertia effect by gathering independent air intake passages for respective cylinder groups and connecting them to gathered air intake passages for the cylinder groups, and providing at positions which are at an equal distance from the air intake ports of respective cylinders, connecting passages connecting independent air intake passages, and control valves at connecting passages. CONSTITUTION:A plurality of independent air intake passages 7 are brought together at every cylinder group GF, GR and connected to gathered air intake passages 8, 8, and respective connection holes 10 which are opened at positions that are at equal distance from air intake ports 6, are provided, and connection is made by means of connecting passages provided with opening/closing valves 11 at center portions. At an engine 1 low speed rotation sphere, opening/closing valves 11 are closed, and the gathered portion of mutually gathered air intake passages 8, 8 at every cylinder group GF, GR becomes the turning-over portion of air intake pressure waves, and resonance synchronization is generated, and air intake is supercharged due to this resonance effect. At an engine 1 high speed rotation sphere, opening/closing valves 11 are opened, and as respective cylinder groups GF, GR are connected by means of connecting passages 9, inertia synchronization that turns these connecting passages 9 into the turning-over portion of air intake pressure waves is generated, and the filling efficiency of air intake can be increase due to this inertia effect.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for a multi-cylinder engine, and particularly to one that supercharges intake air by utilizing dynamic effects.

(Prior art) In recent years, in order to improve the output performance of automobile engines,
It is known to utilize the inertia effect and resonance effect of the intake air within the intake system to increase its filling efficiency.

In supercharging based on the inertia effect of intake air, when the engine is in a predetermined rotation range (synchronous rotation range), the intake negative pressure wave generated at the intake port as the intake valve opens at the beginning of the intake stroke of each cylinder is used as an independent intake. Propagate at the speed of sound toward the upstream side in the passage,
This negative pressure wave is reversed into a positive pressure wave in a predetermined volume part (volume chamber), and this positive pressure wave is propagated downstream along the same path to reach the same intake port just before the intake valve closes. The positive pressure wave forces intake air into the combustion chamber, increasing its filling efficiency.

On the other hand, in supercharging using the resonance effect of intake air, multiple cylinders of the engine are divided into cylinders that are equally spaced on the intake stroke and grouped into multiple cylinder groups, and the independent intake passages of the multiple cylinders in each cylinder group are They are gathered into one collective intake passage (resonant intake passage) at the upstream end, and a pressure inversion section consisting of a volume part is provided at a predetermined position of this collective intake passage. By matching the phase of the basic intake pressure wave generated at the intake port of each cylinder in the cylinder group and the reflected pressure wave reversed at the pressure inversion section in the synchronized rotation range of the engine, the pressure inversion section and each cylinder are connected to each other. The pressure waves of the intake air that propagate back and forth between the cylinders are caused to resonate in the collective intake passage, and due to this resonance, the pressure vibrations that occur individually in each cylinder generate a resonance pressure wave with a large amplitude. is forced into the combustion chamber of the cylinder to increase charging efficiency.

Conventionally, as an intake device aiming at the above-mentioned inertial effect,
As shown in Publication No. 0-40724, an independent intake passage connected to each of a plurality of cylinders is divided into two passages, a first passage and a second passage, in parallel, and the passage length of the - passage is longer than the other passage. At the same time, the upstream ends of the first and second independent intake passages are each provided with independent and separate surge tanks (volume chambers).
There is a system in which inertia tuning of the intake air is performed in both the low-speed rotation range and the high-speed rotation range of the engine by connecting it to the engine.

(Problem to be solved by the invention) By the way, there is a structure in which the independent intake passages of each cylinder are gathered together and connected to a collective intake passage without using the surge tank as described above. Since the inflow of intake air is smooth, the intake resistance is reduced.

However, on the other hand, due to the relationship of smoothing the flow of intake air, the lengths of the independent intake passages may become unequal. Especially when the passage length of the independent intake passage is shortened to obtain an inertia effect in the engine's high speed range,
The problem is that the above-mentioned unequal passage lengths are relatively expanded, and a difference occurs in the inertia synchronized rotational speed between the cylinders, making it impossible to obtain a good inertia effect and deteriorating the distribution of the intake air charge between the cylinders. be.

The present invention has been made in view of the above, and its purpose is to improve intake air flow by connecting independent intake passages together by changing the inversion position of the intake pressure wave during inertia tuning. The objective is to obtain a good inertial effect while achieving a reduction in flow resistance.

(Means for Solving the Problem) In order to achieve the above object, the invention according to claim (1) includes a plurality of cylinder groups divided so that the intervals of the intake strokes are equal for resonance effect. In contrast, the independent intake passages of each cylinder group are communicated with each other by a communication passage at a predetermined position, and the communication passage is used as an inversion part of the intake pressure wave to perform inertial tuning of intake air in each cylinder group.

Specifically, the present invention provides for a multi-cylinder engine having a plurality of cylinders divided into a plurality of cylinder groups so that the intake strokes are equally spaced, the independent intake passages of each cylinder group are collectively assembled. It is characterized by providing a communication passage that connects to the collective intake passage of each cylinder group and communicates the independent intake passages of each cylinder group with each other at equal lengths from the intake port of each cylinder.

Further, in the invention according to claim (2), the collective intake passages between the cylinder groups are brought together, and not only the independent intake passages of each cylinder group but also the independent intake passages between the cylinder groups are communicated with each other by a communication passage. This communication passage is provided with an on-off valve that controls communication of the independent intake passages between the cylinder groups.

That is, the present invention has a plurality of cylinders divided into a plurality of cylinder groups so that the intake strokes are equally spaced, and the independent intake passages of each cylinder group are aggregated to form a collective intake passage for each cylinder group. The common intake passages between the cylinder groups are connected to each other, and the independent intake passages of each cylinder group and the independent intake passages between multiple cylinder groups are connected to each other by a communicating passage at a position of equal length from the intake port of each cylinder. The communication passage is provided with an on-off valve that controls communication of the independent intake passages between the cylinder groups.

(Function) With the above configuration, in the invention according to claim 11, the communication passage communicates the independent intake passages of each cylinder group at positions with equal lengths from the intake port, so that the communication passage At the time of inertia tuning, the pressure wave of the intake air becomes a volume part that reverses,
This allows an inertial effect to be obtained. Since the intake pressure waves are reversed in the communication passage in this way, the gathering part of the independent intake passages on the upstream side does not need to be the pressure wave reversal part, and the intake air flows smoothly from the collective intake passage to each independent intake passage. Therefore, it is possible to reduce the intake resistance and increase the inertial effect at the same time.

In the invention according to claim (2), since the collective intake passages between the cylinder groups are grouped together, a resonance effect can be obtained in which this grouped portion serves as a reversal portion of the intake pressure wave. At that time, if the inertia effect is obtained by communicating the intake passages of the cylinder groups in the high engine speed range higher than this resonance tuning speed,
The resonance effect between the cylinder groups causes a torque reduction effect. However, the independent intake passages between the cylinder groups are communicated by a communication passage, and an on-off valve is installed in this communication passage, so the on-off valve is controlled to close in the low engine speed range and open in the high engine speed range. Then, in the high-speed rotation range, the on-off valve is opened and the independent intake passages between the cylinder groups are communicated by the communication passages. Therefore, the resonance effect between the cylinder groups is suppressed, so that the inertia effect can be effectively utilized.

(Example) Embodiments of the present invention will be described below based on the drawings.

1 and 2 show a first embodiment of the invention.

In the figure, 1 is a DO having left and right banks BL and BR.
This engine 1 is an HC type V-type 1OH0 engine, and includes a cylinder block 2 having a V-shaped cross section, and left and right cylinder heads 3L assembled on the top surface of the cylinder block 2.
, 3R, and two pairs of cylinder head covers 41, 4R assembled on the upper surfaces of the cylinder heads 3L, 3R. The cylinder block 2 of the left bank BL (the one on the left in the figure) has six odd-numbered cylinders C+, C3, and Cs: first, third, fifth, seventh, ninth, and eleventh.

C7, Cg, and Cn, and the cylinder block 2 of the right bank BR (the one on the right in the figure) has six even-numbered cylinders C2, 2nd, 4th, 6th, 8th, 10th, and 12th. C
4, C6, Cs, CIO, and CI2 are formed in series in the bank length direction, and these cylinders C1 to C12 are, for example, 1st cylinder 01 - 12th cylinder C12 → 9th cylinder C9 - 4th cylinder.
Cylinder C4 - 5th cylinder C5 - 8th cylinder C8 - 11th cylinder C
11 - Node 2 cylinder C2 - 3rd cylinder C3 - 10th cylinder CID
The intake stroke proceeds in the order of - node 7 cylinder C7 - 6th cylinder 6.

In this embodiment, the six cylinders C1 to C12 of each bank BL and BR are divided into two cylinder groups GF and GR, front and rear, for each three cylinders so that the intake strokes are equally spaced from each other. There are said to be four cylinder groups in total.

Bank BL of each of the above cylinder heads 3L and 3R.

There are intake valves 5 for each cylinder C1 to C12 on the side between BR.
Intake ports 6 communicating through the intake ports 6 are opened, and each intake port 6 is connected to a downstream end of an independent intake passage 7, respectively. Each independent intake passage 7 goes upward and then curves to form the cylinder head 3 of the corresponding bank BL, BR.
L and 3R extend upward, and their upstream ends are connected to the downstream ends of collective intake passages 8.8 for each cylinder group GF and GR, respectively. Specifically, three independent intake passages 7, 7° for each cylinder group GF, GR...
Of these, the independent intake passage 7 at the center (inside) of the front and rear ends converges with the independent intake passage 7 at the front and rear ends of the cylinder row (the front end for the front cylinder group GF, and the rear end for the rear cylinder group GR). The gathering part is on the center side of the cylinder row (front cylinder group GF
The collective intake passage 8
It is connected to the. With such a connection structure, the independent intake passages 7 of each cylinder group CF and GR branch smoothly from the collective intake passage 8, thereby reducing intake resistance.

The collective intake passages 8, 8 for each of the cylinder groups GF and GR have a portion extending from the downstream end toward the upstream side horizontally toward the center of the cylinder row, and are gathered together there. The upstream end of the collective intake passage 8 extends between the banks BL and BR, and then curves toward the rear above the intake port 6, and the upstream end is connected to a throttle body (not shown).

The independent intake passages 7, 7. A communication path 9 extending parallel to the cylinder row is provided below the cylinders.

This communication passage 9 includes three independent intake passages 7.7. for each cylinder group GF and GR. Communication hole 10°10, respectively.
The communication holes 10 communicate with each other through the intake port 6.
The communicating passage 9 connects three independent intake passages 7, 7 . . . for each cylinder group GF, GR.・・・
- They communicate with each other at positions where they are of equal length from the intake port 6. The communication path 9 is connected to both cylinder groups GF and G.
Independent intake passage between R 7, 7. It also communicates with...
An on-off valve 11 for opening and closing the communication passage 9 is disposed in the center thereof, and this on-off valve 11 is set to close in a low speed rotation range of the engine 1 and open in a high speed rotation range.

In the figure, 21 is an exhaust port that is opened and closed by an exhaust valve 22, and 23 is an injector.

Next, the operation of the above embodiment will be explained.

The on-off valve 11 of the communication passage 9 is controlled to open or close depending on the rotation range of the engine 1, and when the engine 1 is in the low-speed rotation range, the on-off valve 11 is closed. In this state, cylinder groups GF, GR
The collective portion of each intake passage 8.8 becomes an inversion part of the intake pressure wave, causing resonance tuning, and the intake air is supercharged by this resonance effect.

On the other hand, when the engine 1 reaches a high speed range, the on-off valve 1
1 is opened. Independent intake passage 7 for each cylinder group GF, GR
,7. ... Since they are communicated with each other by a communication passage 9 at positions of equal length from the intake port 6, inertial synchronization occurs in which the communication passage 9 serves as an inversion part of the intake pressure wave, and this inertial effect causes the intake air to fill up. Efficiency can be increased. In this high-speed rotation range, the collective intake passage 8 between the cylinder groups GF and GR is
．． A torque reduction effect is likely to occur due to the resonance effect caused by the gathering portion of cylinders 8, but the communication passage 9 is opened by opening the on-off valve 11, and the independent intake passages 7 and 7 between the cylinder groups GF and GR are communicated with each other. Therefore, this communication suppresses the resonance effect described above, thereby making it possible to obtain a good inertial effect.

Therefore, by communicating the independent intake passages 7, 7 of the cylinder groups GF, GF2 with the communication passage 9 at positions of equal length from the intake port 6, the communication passage 9 can be used to prevent the reversal of the intake pressure wave during inertial tuning. Therefore, the gathering part of the collective intake passages 8, 8 on the upstream side does not need to be a pressure wave reversal part, and in each cylinder group GF, GR, the intake air flows from the collective intake passage 8 to the independent intake passage 7. ,7. ... can be set to flow smoothly, thereby achieving both a reduction in intake resistance and an increase in inertia effect.

(Other Embodiments) FIG. 3 shows a second embodiment. In addition, in each of the following examples,
The same parts as in FIGS. 1 and 2 are given the same reference numerals, and detailed explanation thereof will be omitted.

In this embodiment, the intake stroke is, for example, first cylinder C]-third cylinder
4 in the order of cylinder C3 - 4th cylinder C4 - 2nd cylinder C2
In an in-line four-cylinder engine 1 having four cylinders C1 to C4, the first and second cylinders C1 and C2 form a front cylinder group GF, and the third and fourth cylinders C, C4 form a rear cylinder group GR. Divided into two cylinder groups GF and GR, each cylinder group G
The independent intake passages 7, 7 of F and GR are gathered together and connected to a collective intake passage 8 for each cylinder group GF, GR, and both of these collective intake passages 8.8 are assembled. In addition, each cylinder group GF
, GR's independent intake passages 7, 7 have the same length from the intake port 6 to the upstream end gathering portion, and are communicated with each other by a communication passage 9 at the upstream end gathering portion.

In this embodiment, an independent intake passage 7 between the cylinder groups GF and GR
．． 7 or the communication path 9 at the gathering part which is of equal length from the intake port 6
Therefore, even if the distances to the collective portion of the collective intake passages 8, 8 are unequal for each of the cylinders C1 to C4, this effect can be eliminated.

In the third embodiment shown in FIG. 4, the intake stroke is, for example, first cylinder C1 - fifth cylinder C5 - third cylinder c3 - sixth cylinder C6 -
Six cylinders C in the order of 2nd cylinder C2 → 4th cylinder C4
1 to C6, the first
~3rd cylinder C]~C3 is the front cylinder group GF, and the 4th cylinder~
The sixth cylinders C4 to C6 constitute a rear cylinder group GR and are divided into two cylinder groups GF and GR. In addition, each cylinder group GF
.

GR independent intake passage 7,7. ... are gathered together and connected to a collective intake passage 8 for each cylinder group GF, GR, and these collective intake passages 8, 8 are assembled. The independent intake passages 7, 7°, . . . of each cylinder group CF, GR are communicated with each other by a communication passage 9 at portions having equal lengths from the intake port 6.

Therefore, in this embodiment as well, the independent intake passages 7, 7 between the cylinder groups GF and GR are communicated with each other by the communication passage 9 at the portions having the same length from the intake port 6, so that the same effect as in the second embodiment is achieved. effect can be obtained.

FIG. 5 shows a fourth embodiment, in which a collective intake passage 8.8 between cylinder groups GF and GR is communicated.

That is, in this embodiment, in the same intake system as in the third embodiment, the collective intake passages 8.8 of the cylinder groups GF and GR are
The distance from the downstream end to the upstream gathering part is relatively long;
These two collective intake passages 8, 8 are communicated with each other by a communication passage 12 for the collective intake passage 8 at a portion having the same length from the downstream end.

Further, as in the first embodiment, the independent intake passages 7.7 between the cylinder groups CF and GR are communicated with each other by a communication passage 9 provided with an on-off valve 11 for variable resonance.

Therefore, in this embodiment, in addition to being able to achieve the same effects as in the first embodiment, the cylinder groups GF, G
Since the common intake passage 8.8 of R is communicated with the communication passage 12 at a position of equal length from the downstream end, the cylinder groups GF, G
The resonance effect between R can be balanced.

FIG. 6 shows a fifth embodiment, in which the series 6
In the cylinder engine 1, the passage lengths of the collective intake passages 8, 8 of both cylinder groups GFGR to the collective part are made equal lengths, and this embodiment also provides the same effect as the third embodiment.

FIGS. 7 and 8 show a sixth embodiment. This example is
The invention is applied to a V-type six-cylinder engine 1 having six cylinders C1 to C6, the first to sixth cylinders, whose intake strokes are performed in the order of cylinder numbers, and the left bank BL has the first, third, and fifth cylinders. Three odd-numbered cylinders C+, C3, and C5 are formed in the right bank BR, and three even-numbered cylinders C::, Ca, and C6 are formed in the right bank BR, respectively.
The six cylinders C1 to C6 are grouped into two cylinder groups GL and GR for each bank BL and BR. Each cylinder C1~
The intake port 6 of C6 opens between banks BL and BR,
independent intake passages 7, 7 . connected to each intake port 6;・
... is the left bank BL after crossing between cylinder groups GL and GR
It extends upward and is connected there to the collective intake passages 8, 8 for each cylinder group GL, GR. The two collective intake passages 8, 8 are on the left bank B, converge in the upper part, and then extend rearward.

And an independent intake passage 7.7 between the cylinder groups GL and GR.
In this case, the intersection between cylinder groups GL and GR is intake port 6.
The length is equal from 9 to 9, and one communication path 9 is formed at this intersection.
are connected to each other.

Therefore, in this embodiment, even if the cylinder groups GL and GR are grouped into cylinders C1 to c6 for each bank BL and BR, the independent intake passage 7 between both cylinder groups GL and GR is provided by one communication passage 9. There is an advantage that .7 can be communicated.

FIGS. 9 and 10 show a seventh embodiment, which has the same configuration as the sixth embodiment, but includes both cylinder groups GL.

The independent intake passages 7, 7 of the GR do not intersect between the banks BL, BR, and extend substantially parallel to the left bank B and upward. The independent intake passages 7, 7 of both cylinder groups GL, G communicate with each other through a rectangular annular communication passage 9 at positions having the same length from the intake port 6. The rest of the structure is the same as that of the sixth embodiment, and therefore this embodiment can also provide the same effects.

(Effect of the invention) As explained above, according to the invention claimed in claim (1),
A plurality of cylinders are divided into cylinders with different intake strokes, and the cylinders of each cylinder group are connected to a collective intake passage for each cylinder group via an independent intake passage, and the independent intake passages of each cylinder group are connected to each other from the intake boat. By providing communicating passages that communicate at equal length positions, it is possible to obtain an inertial effect by using the communicating passage as a volume part in which the intake pressure wave is reversed during inertia tuning, so that independent intake passages and collective intake passages can be The connecting portion with the air intake can be set so that the intake air flows smoothly, thereby achieving both a reduction in intake resistance and an increase in the inertia effect.

Further, according to the invention according to claim (2), the collective intake passages between the cylinder groups are brought together, and the communication passages communicate not only the independent intake passages of each cylinder group but also the independent intake passages between the cylinder groups. By installing an on-off valve in the communication passage to control the communication of the independent intake passages between the cylinder groups, in the synchronized rotation range of the inertial effect, the gathering part of the collective intake passage between the cylinder groups is reversed by the intake pressure wave. Due to the resonance effect, the torque reduction effect can be suppressed, and the inertia effect can be effectively utilized.

[Brief explanation of drawings]

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a plan view of an engine and an intake system, and FIG. 2 is a longitudinal sectional view thereof. FIG. 3 is a schematic plan view of the engine and intake system in the second embodiment. Figures 4 to 6 are respectively 3 to 6.
FIG. 3 is a diagram corresponding to FIG. 3 showing a fifth embodiment; FIG. 7 is a view corresponding to FIG. 3 showing the sixth embodiment, and FIG. 8 is a schematic front view of the same engine and intake system. FIG. 9 shows the third embodiment of the seventh embodiment.
FIG. 10 is a diagram equivalent to FIG. 8. 1...Engine BL, BR...Bank C1 to CI2...Cylinder GF, GR, GL...Cylinder group 6...Intake port 7...Independent intake passage 8...Common intake passage 9 ...Communication path 11...Opening/closing valve

Claims (2)

[Claims] (1) In a multi-cylinder engine that has a plurality of cylinders divided into a plurality of cylinder groups so that the intake strokes are equally spaced, the independent intake passages of each cylinder group are grouped together to form a collective intake passage for each cylinder group. What is claimed is: 1. An intake system for a multi-cylinder engine, characterized in that a communication passage is provided which connects the independent intake passages of each cylinder group to each other at a position of equal length from the intake port of each cylinder. (2) In a multi-cylinder engine that has a plurality of cylinders divided into a plurality of cylinder groups so that the intake strokes are equally spaced, the independent intake passages of each cylinder group are grouped together to form a collective intake passage for each cylinder group. The common intake passages between the cylinder groups are connected to each other, and the independent intake passages of each cylinder group and the independent intake passages between the cylinder groups are communicated with each other by communication passages at positions of equal length from the intake port of each cylinder. An intake system for a multi-cylinder engine, characterized in that the communication passage is provided with an on-off valve that controls communication between independent intake passages between cylinder groups.