JPH04132829A - Intake device for engine - Google Patents

Abstract

PURPOSE:To install a communication path at a position of equal length from intake ports by providing the communication path extending in the direction of an row of cylinders for communicating independent intake paths with each other, between curved portions positioned outside and curved portions positioned inside. CONSTITUTION:In a straight-type four-cylinder engine 1, independent intake paths 5a-5d communicated with respective cylinders 2a-2d on one side are installed. The respective independent intake paths 5a-5d, after curving collect at one position on the upstream ends. In this case, the curve d portion 22, 23 of the respective independent intake paths 5a-5d, as viewed from the row of cylinders, deviate mutually inward and outward. A communication path 46 in the direction of the row of cylinders for communicating the independent intake paths 5a-5d with each other is installed between the curved portions 23 positioned outside and the curved portions 22 positioned inside. Consequently, the communication path 46 can be installed at a position of equal length from intake ports 3 of the respective independent intake paths 5a-5d.

Description

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

(Prior art) Recently, in order to improve the output torque of an engine, the filling efficiency of the intake air has been increased by supercharging the intake air supplied to the engine cylinders using dynamic effects such as the intake inertia effect. This is what is being done.

That is, in supercharging based on the intake inertia effect, when a negative pressure wave of intake air is generated at the intake port as the intake valve opens at the beginning of the intake stroke of each cylinder in a predetermined engine rotation range (tuned rotation range), This intake negative pressure wave is propagated at the speed of sound toward the upstream side within an independent intake passage connected to the intake port, and this negative pressure wave is reversed into a positive pressure wave in a predetermined volume portion (volume chamber). Furthermore, this positive pressure wave is propagated downstream along the same path at the speed of sound, reaching the intake port of the same cylinder at the end of the intake stroke just before the intake valve closes, and this positive pressure wave pushes the intake air into the combustion chamber. The filling efficiency is increased.

Generally, a surge tank is used as a gathering part to reverse the intake pressure waves, but in this surge tank, the length from the upstream passage to each independent intake passage, or the independent intake passage itself Since the length of each cylinder is different, there are problems such as the distribution of intake air and the effect of intake inertia to each cylinder are not uniform.

For this reason, conventionally, in Utility Model Application Publication No. 60-88062,
The upstream ends of the independent intake passages that communicate with each cylinder from one side of the engine are formed into a substantially truncated conical space, with the downstream end of the main intake passage at the small diameter end of the space, and the plurality of independent intake passages at the large diameter end. It has been proposed to connect the independent intake passages, respectively, and arrange the upstream end openings of the independent intake passages symmetrically with respect to an axis passing through the axis of the downstream end opening of the main intake passage. According to this, the distance from the downstream end opening of the main intake passage to the upstream end opening of each independent intake passage in the gathering part located in the center of the cylinder row direction of the engine is approximately equal for each independent intake passage, and each cylinder The distribution of intake air is made more uniform, and the intake flow path from the main intake passage to each cylinder is no longer sharply curved, reducing intake resistance.Furthermore, the upstream end openings of each independent intake passage are arranged close to each other. , each independent intake passage or another independent intake passage can be used as a volume chamber for the intake inertia effect, so that the size of the gathering part itself can be made compact.

(Problem to be Solved by the Invention) By the way, by connecting the independent intake passages with each other through a communication passage or the like at a position of equal length from the intake port in the middle of each independent intake passage, the inertia-tuned rotation range can be extended to a higher rotation range. In some cases, supercharging is performed by the intake inertia effect both in the existing inertia-tuned rotation range and in the existing inertia-tuned rotation range.

In that case, in order to make the intake system more compact, each independent intake passage is curved and the gathering part at its upstream end is placed above the engine. It becomes difficult to provide a communication passage that allows the independent intake passages to communicate with each other at a position that has the same length from the intake port in the middle of the independent intake passage.

The present invention has been made in view of this point, and its purpose is to shift the curved portion of each independent intake passage inward and outward when viewed from the direction of the cylinder row, and to utilize the inside and outside of the curved portion as appropriate. Accordingly, the communicating passages are provided at positions having the same length from the intake port of each independent intake passage.

(Means for Solving the Problem) In order to achieve the above object, the solution taken by the invention according to claim (1) is to provide an engine having a plurality of cylinders with independent communication with each cylinder from one side of the engine. The present invention is based on an engine intake system in which an intake passage is provided, and each of the independent intake passages is curved and then their upstream ends are gathered at one place. The curved portions of each of the independent intake passages are shifted inwardly and outwardly from each other when viewed from the direction of the cylinder row, and between the curved portion located on the outside and the curved portion located on the inside, the curved portion extends in the direction of the cylinder row and is independent. The structure is such that a communication passage is provided that allows the intake passages to communicate with each other.

Further, the solution proposed by the invention according to claim (2) is such that the gathering portion at the upstream end of each independent intake passage is located above the engine and on one side in the direction of the cylinder row. .

Further, the solution taken by the invention according to claim (3) is such that the gathering portion at the upstream end of each independent intake passage is located above the engine and approximately at the center in the direction of the cylinder row. .

Further, the solution taken by the invention according to claim (4) is that an engine having a plurality of cylinders is provided with independent intake passages communicating with each cylinder from one side thereof, and each independent intake passage is curved. The present invention is based on an engine intake system whose upstream ends are gathered at one location above the engine and approximately at the center in the cylinder row direction. Then, the curved portions of each of the independent intake passages are shifted inwardly and outwardly from each other when viewed from the direction of the cylinder row, and the curved portion located on the outside and the curved portion located on the inside are arranged substantially perpendicular to the direction of the cylinder row. The structure includes a communication passage extending in a direction in which the independent intake passages communicate with each other.

Furthermore, the solution taken by the invention according to claim (5) is:
A rotary valve is provided inside the communication passage for rotationally controlling communication between the communication passage and each independent intake passage and its interruption.

(Function) According to the above configuration, in the invention according to claim (1), the curved portion of each independent intake passage is arranged so that one The curved part of the passage is arranged on the outside when viewed from the direction of the cylinder row, and the curved part of the other independent intake passage is arranged on the inside when seen from the direction of the cylinder row, and the curved parts are shifted inwardly and outwardly from each other, and the curved part is located on the outside. A communication passage that extends in the direction of the cylinder row and communicates the independent intake passages with each other is provided between the inner intake passage and the inner curved portion. As a result, the distance between the communication passage and the intake port is increased by the distance from the intake port that is shorter in one independent intake passage. The distance from the intake port is made closer to the outside of the curved portion located on the inside and the other independent intake passage by the distance from the intake port. The communication passages are communicated with the inside of the curved portion located on the outside, and are provided at equal length positions from the intake ports of each independent intake passage.

In addition, as mentioned above, the communication path is connected to the curved part located on the outside,
Since the communication passage is provided extending in the direction of the cylinder row between the curved portion located on the inside, the communication passage is connected to each independent intake passage approximately orthogonally, and each independent intake passage is connected to one
This increases the rigidity and strength of the entire independent intake passage.

In addition, in the invention according to claim 2, since the gathering portion at the upstream end of each independent intake passage is provided above the engine and on one side in the cylinder row direction, the intake port of each independent intake passage In order to make the passage lengths of the cylinders equal in length, the curved part of the independent intake passage of the cylinder located near the collecting part should be placed on the inner side, which is closer to the intake port when viewed from the direction of the cylinder row, and relative to the collecting part. The curved portions of the independent intake passages of the cylinders located far away are arranged on the outer side, which is far from the intake port when viewed from the direction of the cylinder row, and the curved portions of the independent intake passages are shifted inwardly and outwardly from each other, and the above-mentioned gathering portion Between the curved part of the independent intake passage of the cylinder σ that is close to the cylinder σ, that is, the curved part that is located on the inside, and the curved part of the independent intake passage of the cylinder that is far from the gathering part, that is, the curved part that is located outside, there is a A communication passage is provided that extends from the intake passage to communicate the independent intake passages with each other.Thereby, in the independent intake passage of the cylinder near the gathering part, the communication passage is connected from the intake port to the extent that the distance from the intake port is short. The outside of the curve located on the inside and
In the independent intake passages of the cylinders that are far from the gathering part, the distance from the intake port is shortened by the distance from the intake port. A communication passage is provided at a position having the same length from the intake port of each independent intake passage, and communicating with the inside of the curved portion located on the outside.

In addition, as mentioned above, the communication path is connected to the curved part located on the outside,
Since the communication passage is provided extending in the direction of the cylinder row between the curved portion located on the inside, the communication passage is connected to each independent intake passage approximately orthogonally, and each independent intake passage is connected to one
This increases the rigidity and strength of the entire independent intake passage.

Further, in the invention according to claim (3), since the gathering portion at the upstream end of each independent intake passage is provided above the engine and approximately at the center in the cylinder row direction, the intake port of each independent intake passage In order to make the passage lengths from the cylinders to the same length, the curved part of the independent intake passage of the cylinder located far from the collecting part should be placed at a position close to or at a distance from the intake port when viewed from the direction of the cylinder row, relative to the collecting part. The curved portions of the independent intake passages of the cylinders located close to each other are arranged at positions far from the intake ports when viewed from the direction of the cylinder row, and the curved portions in the middle of each independent intake passage are shifted inwardly and outwardly from each other. Between the curved part of the independent intake passage of the cylinder far from the collecting part, that is, the curved part located on the inside, and the curved part of the independent intake passage of the cylinder near the collecting part, that is, the curved part located outside, A communication passage is provided that extends in the column direction and allows the independent intake passages to communicate with each other.

As a result, the communication passage is separated from the intake port by the distance from the intake port that is shorter in the independent intake passage of the cylinder that is far from the gathering part. The distance from the intake port is made closer to the outside of the curved portion located on the inside and the independent intake passage of the cylinder near the collecting portion, in proportion to the distance from the intake port that is greater. A communication passage is provided at a position having the same length from the intake port of each independent intake passage, and communicating with the inside of the curved portion located on the outside.

In addition, as mentioned above, the communication path is connected to the curved part located on the outside,
Since the communication passage is provided extending in the direction of the cylinder row between the curved portion located on the inside, the communication passage is connected to each independent intake passage approximately orthogonally, and each independent intake passage is connected to one
This increases the rigidity and strength of the entire independent intake passage.

Further, in the invention according to claim (4), the curved portion of each independent intake passage provided above the gathering part or the engine and approximately at the center in the direction of the cylinder row is connected to the intake port of each independent intake passage. In order to make the passage lengths from the cylinders to the same length, the curved part of the independent intake passage of the cylinder located far from the collecting part should be placed on the inner side, which is closer to the intake port when viewed from the direction of the cylinder row, relative to the collecting part. The curved portions of the independent intake passages of the cylinders that are located close to each other are arranged on the outer side far from the intake port when viewed from the direction of the cylinder row, and the curved portions are shifted inwardly and outwardly from each other, and are far from the above-mentioned gathering portion. Between the curved portion of the independent intake passage of the cylinder, that is, the curved portion located on the inside, and the curved portion of the independent intake passage of the cylinder, that is, the curved portion located on the outside, near the gathering portion, there is a curved portion that is approximately perpendicular to the cylinder row direction. A communication passage is provided which extends in the direction of the intake passage and connects the independent intake passages with each other. As a result, the communication passage has a curved part where the distance from the intake port is short in the independent intake passage of the cylinder far from the gathering part,
The independent intake passages of the cylinders that are close to the gathering part communicate with the curved parts that are farther away from the intake port, and the communication passages are provided at equal length positions from the intake port of each independent intake passage.

In addition, as mentioned above, the communication path connects to the curved part located far away,
Since the connecting passage is provided to extend in a direction perpendicular to the direction of the cylinder row between the adjacent curved parts, the communicating passage is connected to each independent intake passage approximately perpendicularly to the cylinder row direction.
Each independent intake passage becomes one rigid body, increasing the rigidity and strength of the entire independent intake passage.

Furthermore, in the invention according to claim (5), since the rotary valve that controls communication and disconnection between the communication passage and each independent intake passage by rotation is provided inside the communication passage, each independent intake passage can be separated by opening the pulp. The required smoothness can be made more compact than in the case where the intake passage is communicated within the volume chamber.

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

1 and 2 show a first embodiment in which the present invention is applied to an in-line four-cylinder engine. In the figure, 1 is the first to fourth
The engine is an in-line four-cylinder engine having four cylinders 2a to 2d, and the first to fourth cylinders 28 to 2d are arranged in series at equal intervals. These cylinders 2a to 2d are, for example, first cylinder 2a-third cylinder 2c-
The intake stroke progresses in the order of the second cylinder 2b to the fourth cylinder 2d.

4 is an intake passage that supplies intake air to each of the cylinders 2a to 2d, and the downstream end of this intake passage 4 is connected to each cylinder 2a, 2b, 2c.
, 2d, respectively.

5d, and a substantially truncated conical intake gathering portion 6 (gathering portion) connected to the upstream ends of the independent intake passages 5a, 5b, 5c, and 5d.
and a main intake passage 7 connected to the upstream end of the intake collecting section 6.
It is equipped with These are located on one side of the engine 1 (first
(lower side in the figure), and its upstream end is connected to an air cleaner (not shown). An air flow meter (not shown) for detecting the amount of intake air is provided in the main intake passage 7 on the downstream side of the air cleaner. Further, the upstream ends of each of the independent intake passages 5a, 5b, 5c, and 5d are gathered in an intake collecting portion 6 in close proximity to each other and communicated with a main intake passage 7.

The intake collecting section 6 has an upstream end 6a that opens at the downstream end of the main intake passage 7, and a cross-sectional area larger than the upstream end, and has an upstream end 6a that is open at the downstream end of the main intake passage 7, and has a cross-sectional area larger than the upstream end. The downstream end 6b is arranged in a substantially square shape and opens so that the upstream end surrounds the center axis 9 of the downstream end opening of the main intake passage 7, and the cross-sectional area from the upstream end 6a to the downstream end 6b is is increasing smoothly. The intake air collecting section 6 is located above the engine 1 and on one side (on the left side in FIG. 1) in the direction of the cylinder row.

Further, each of the independent intake passages 5a, 5b, and 5c.

5d, each independent intake passage 5a of the first cylinder 2a and the second cylinder 2b located near the intake collecting portion 6;
, 5b, these intake pipes 21 are horizontally extended in a direction away from the engine 1 side, then curved by bending to extend upward, and then bent again so as to extend horizontally toward one side in the cylinder row direction. The first part is curved due to processing.
A curved portion 22 is provided. On the other hand, the intake collecting section 6
The third cylinder 2C and the fourth cylinder 2 are located far away from each other.
These intake pipes 2 are connected to each independent intake passage 5c, 5d of d.
1 was extended horizontally in a direction away from the engine 1 side, and then bent by bending so that it drew a semicircular arc upward and extended horizontally toward one side in the direction of the cylinder row. A second curved portion 23 having a steeper curve than the first curved portion 22 is provided.

Furthermore, as shown in FIG. 3, each independent intake passage 5a of the first cylinder 2a and the second cylinder 2b.

5b communicates with the downstream end 6b of the intake air collecting section 6 above a horizontal line m passing through the central axis 9 of the main intake passage 7 and the common central axis 9 of the air intake collecting section 6. Further, each of the independent intake passages 5c and 5d of the third cylinder 2C and the fourth cylinder 2d is arranged with respect to the downstream end 6b of the intake collecting section 6, with respect to the horizontal line m passing through the central axis 9 of the above mentioned intake collecting section 6. It is connected to the bottom.

and each of the independent intake passages 5a, 5b, and 5c.

5d, the first one located near the intake collecting part 6
Each independent intake passage 5a, 5 of the cylinder 2a and the second cylinder 2b
a substantially intermediate portion of the first curved portion 22 at b, and a second curved portion 2 in each independent intake passage 5c, 5d of the third cylinder 2c and fourth cylinder 2d located far from the intake collecting portion 6;
3 is shifted in the inward and outward directions when viewed from diagonally above the fourth cylinder 2d in the cylinder row direction. Then, the outside (lower side in FIG. 1) of the substantially intermediate portion of the first curved portion 22 of each independent intake passage 5a, 5b of the first cylinder 2a and second cylinder 2b, which are close to the intake collecting portion 6, and the intake Each independent intake passage 5 of the third cylinder 2C and the fourth cylinder 2d which are far from the gathering part 6
A rotary valve 41 extending substantially parallel to the direction of the cylinder row is provided between the inner side (the upper side in FIG. 1) of the substantially intermediate portion of the second curved portion 23 of the second curved portions 23 and 5d.

The rotary valve 41 is connected to each independent intake passage 5a.

5b, 5c, 5d intake pipes 21. The first cylinder is integrally formed with... and is a cylinder at both ends. A cylindrical casing 42 extends substantially parallel to the direction of the cylinder row between the independent intake passages 5a and 56 of the fourth cylinders 2a and 2d, and inside the casing 42 are the independent intake passages 5a.

5b, 5c, and 5d, communicating holes 43 open at equal length positions from the intake port 3. It communicates through... Further, a closed cylindrical valve body 45 supported by a support shaft 44 is rotatably fitted into the casing 42, and a communication passage 46 is formed within the valve body 45. The outer peripheral wall of the valve body 45 has a plurality of valve holes 47 that communicate between the inside and outside of the valve body 45.・
... is opened, and this valve hole 47. . . are arranged parallel to the rotation axis of the valve body 45 and at positions corresponding to the communication holes 43. A lever 48 is attached to the support shaft 44, and this lever 48 is connected to an actuator 49.
By rotating the valve body 45 with the actuator 49, each valve hole 47 is connected to the corresponding communication port 4.
3 at the same time, the rotary valve 41 is opened, and the independent intake passages 5a, 5b, 5c, and 5d are simultaneously communicated via the communication passage 46 in the valve body 45, thereby connecting each cylinder 2a.

The volume chamber that serves as the inversion part of the intake pressure wave during inertial tuning at 2b, 2c, and 2d is switched to the intake air collecting section 6 or the communication path 46.

Therefore, in the above embodiment, each cylinder 2a, 2b, 2c
, 2d, respectively.
c and 5d are curved so as to extend above the engine 1 and to one side in the direction of the cylinder row, and are gathered together at the downstream end 6b of the intake collecting portion 6, without increasing the width of the engine 1 in the lateral direction. It is compactly arranged. In that case, the independent intake passages 5c and 5d of the third cylinder 2C and the fourth cylinder 2d, which are located far from the intake collecting part 6, 2 cylinder 2b
The lower part of the downstream end 6b of the intake collecting section 6, that is, the intake collecting part, is a thread path with a short vertical height that suppresses the upward extension by the length in the cylinder row direction compared to the independent intake passages 5a and 5b. Part 6
It communicates with the lower side of the horizontal line m passing through the central axis 9 of the. On the other hand, the independent intake passages 5a and 5b of the first cylinder 2a and the second cylinder 2b, which are close to the intake collecting part 6, are the same as those of the third cylinder 2C and the fourth cylinder 2d, which are far from the intake collecting part 6. A thread having a long vertical height and extending upward so as to wrap around above the horizontal line m passing through the central axis 9 of the intake collecting section 6 (downstream end 6b) by an amount shorter in the cylinder row direction than the passages 5c and 5d. A channel communicates with the upper side of the downstream end 6b. As a result, the independent intake passages 5a, 5b, 5c, 5
d intake pipe 21. ...The length of each cylinder 2a, 2b
, 2c, 2d are of equal length, and independent intake passages 5a, 5b
, 5c, and 5d can be made uniform, and supercharging can be effectively performed by the intake inertia effect.

In that case, each independent intake passage 5a, 5b, 5c.

5d is provided above the engine and on one side in the cylinder row direction, and each independent intake passage 5a, 5
In order to make the lengths of the passages from the intake ports 3 of the intake ports 3 of the intake ports 3, 5c, and 5d of The approximately intermediate position of the first curved portion 22 is located on the inside where the distance from the intake port 3 is close when viewed from the cylinder row direction, and the third cylinder 2C and the fourth cylinder 2d, which are located far away from the intake collecting portion 6, are separated from each other. Approximately intermediate positions of the second curved portions 23 of the intake passages 5c and 5d are arranged on the outer side, which is far from the intake port 3 when viewed from the cylinder row direction, so that the independent intake passages 5a, 5b, 5c
. The curved portion 22, that is, the approximately intermediate position 22 of the first curved portion located on the inside, and the third cylinder 2c that is far from the intake collecting portion 6
and the second of each independent intake passage 5c, 5d of the fourth cylinder 2d.
Each independent intake passage 5 extends in the direction of the cylinder row between the curved portion 23, that is, the approximately intermediate position of the second curved portion 23 located on the outside.
A communication path 46 is formed that allows communication and isolation between a, 5b, 5c, and 5d by rotation of the rotary valve 41 (valve body 45). As a result, in each of the independent intake passages 5g and 5b of the first and second cylinders 2a and 2b, which are close to the intake collecting portion 6, the communication passage 46 has a distance from the intake port 3 corresponding to the short distance from the intake port 3. The first curved part 2 where is released
2 and the independent intake passages 5c and 5d of the third cylinder 2C and the fourth cylinder 2d, which are far from the intake collecting part 6, are made closer in distance from the intake port 3 by the distance from the intake port 3. communicates with the inside of the second curved portion 23,
A rotary valve 41 that switches the volume chamber, which is the inversion part of the intake pressure wave during inertia tuning, to the intake collecting part 6 or the communication passage 46.
Each independent intake passage 5a, 5b, 5c.

It can be easily provided at a position with the same length from the intake port 3 as compared to the intake port 5d.

Further, as described above, since the communication passage 46 is provided extending in the cylinder row direction between the first curved part 22 located on the inside and the second curved part 23 located on the outside, the rotary valve 41 (Communication passage 46) includes each independent intake passage 5a, 5b,
They are connected substantially perpendicularly to 5c and 5d.

Moreover, the rotary valve 41 is formed by bending. The first curved portion 22 has a gentle curve with not much difference in wall thickness on the outside compared to the inside (independent intake passages 5a of the first cylinder 2a and second cylinder 2b that are close to the intake collecting portion 6,
The outer side of the intake pipe 21 where the first curved part 22) of 5b is located, and the second part with a sharp bend where the inner wall thickness is thicker than the outer side.
It is connected so as to straddle the inside of the curved portion 23 (the second curved portion 23 of each independent intake passage 5c, 5d of the third cylinder 2C and fourth cylinder 2d, which are far from the intake collecting portion 6). Become.

As a result, each independent intake passage 5a, 5b, 5c.

Each independent intake passage 5a has a rotary valve 41 extending and connected in a direction perpendicular to 5d.

5b, 5c, and 5d become one rigid body, and the independent intake passage 5
It is possible to increase the rigidity and strength of the entire parts a, 5b, 5c, and 5d.

Furthermore, as described above, the communication passage 46 and each independent intake passage 5a,
Since the rotary valve that controls communication with 5b, 5c, and 5d by rotation is installed inside the communication passage, the required space is more compact than when the valve is opened to communicate each independent intake passage within the volume chamber. It can be made into something.

Moreover, as described above, the independent intake passages 5a and 5b of the first cylinder 2a and the second cylinder 2b, which are close to the intake collecting part 6, communicate with each other below the horizontal line m passing through the central axis 9 of the intake collecting part 6. independent intake passages 5a, 5b (intake collecting section 6
The independent intake passages 5c of the third cylinder 2C and the fourth cylinder 2d which are far from each other.

5d), and is connected by a long yarn path with a vertical height that extends upward so as to wrap around above the horizontal line m passing through the central axis p of the intake collecting part 6.
In the independent intake passages 5a, 5b of the first cylinder 2a and the second cylinder 2b, which are close to each other, the sharp curvature of the intake pipes 21, 21 themselves is relaxed, and intake resistance can be reduced.

(Other Embodiments) FIGS. 4 and 5 show a second embodiment. The same parts as in FIG. 1 are given the same reference numerals and detailed explanations are omitted. This is applied to engine 1.

That is, in this embodiment, the intake air collecting section 6 is located above the engine 1 and at the center in the cylinder row direction. Moreover, each independent intake passage 5a.

These intake pipes 21 are connected from the engine 1 side to the independent intake passages 5b, 5c of the second cylinder 2b and third cylinder 2c, which are located close to the intake collecting portion 6 among the intake passages 5b, 5c, and 5d. A first curved portion 22 is provided which extends horizontally in the direction of separation, then curves and extends upward, and then curves again so as to extend obliquely upward toward the center in the direction of the cylinder row. On the other hand, these intake pipes 21 are connected to the independent intake passages 5a and 5d of the first cylinder 2a and the fourth cylinder 2d, which are located far from the intake collecting part 6, in the engine 1.
It was extended horizontally in a direction away from the side, then curved and extended upward, and then curved again so as to extend diagonally upward toward the center of the cylinder row direction. A second curved portion 23 having a steeper curve than the first curved portion 22 is provided. The first curved portion 22 and the second curved portion 23 are such that the first curved portion 22 is the second curved portion 23 when viewed from the cylinder row direction.
They are provided on the outside, which is farther away from the intake port 3, and are offset from each other in the inner and outer directions.

Further, each independent intake passage 5b, 5c of the second cylinder 2b and third cylinder 2C is connected to the downstream end 6b of the intake collecting section 6.
However, it is communicated above the horizontal line m passing through the central axis 11+. Further, the independent intake passages 5a and 5d of the first cylinder 2a and the fourth cylinder 2d are communicated with the downstream end 6b of the intake collecting portion 6 below the horizontal line m. A first curved portion in each of the independent intake passages 5b, 5c of the second cylinder 2b and third cylinder 2C, which are located close to the intake collecting portion 6, among the independent intake passages 5a, 5b, 5c, and 5d. 22, that is, a substantially middle portion of the first curved portion 22 located on the outside, and a second curved portion in each independent intake passage 5a, 5d of the first cylinder 2a and fourth cylinder 2d located far from the intake collecting portion 6. 23, that is, the substantially middle portion of the second curved portion 23 located on the inner side is shifted in the inward and outward directions when viewed from the cylinder row direction.

A rotary valve 41 extending substantially parallel to the cylinder row direction is provided between a substantially middle portion of the first curved portion 22 located on the outside and a substantially middle portion of the second curved portion 23 located on the inside. There is.

Therefore, in this embodiment, each independent intake passage 5a, 5
The intake collecting portions 6 of the intake passages 5a, 5c, and 5d are provided above the engine and approximately in the center in the cylinder row direction, and the passage lengths from the intake ports 3 of the independent intake passages 5a, 5b, 5c, and 5d are made equal. In order to increase the length, each independent intake passage 5 of the first cylinder 2a and the fourth cylinder 2d is located far from the intake collecting part 6.
The approximately middle portion of the second curved portion 23 at points a and 5d is located on the outside far from the intake port 3 when viewed from the cylinder row direction, and the second cylinder 2b and the third cylinder located close to the intake collecting portion 6. 2c, each independent intake passage 5b.

Approximately middle portions of the first curved portions 22 in the independent intake passages 5a, 5b, 5c, and 5d are provided on the inner side nearer to the intake ports when viewed from the cylinder row direction, and the first and second curved portions 22. 23 or so, they were brushing each other in and out,
The first cylinder 2a and the fourth cylinder far from the intake collecting part 6
The outside of the substantially intermediate portion of the second curved portion 23 in each independent intake passage 5a, 5d of the cylinder 2d, and each independent intake passage 5 of the second cylinder 2b and third cylinder 2C close to the intake collecting portion 6.
Each independent intake passage 5a, 5b extends in the direction of the cylinder row between the inner side of the substantially intermediate portion of the first curved portion 22 in b, 5c.
, 5c, and 5d are provided with a rotary valve 41 for communicating and cutting off communication with each other.

As a result, the rotary valve 41 has a distance from the intake port in each of the independent intake passages 5a and 5d of the first cylinder 2a and the fourth cylinder 2d, which are far from the intake collecting portion 6, to the extent that the distance from the intake port 3 is short. The outer side of the substantially intermediate portion of the first curved portion 22 that is separated from the intake air collecting portion 6 and the independent intake passages 5b and 5c of the second cylinder 2b and the third cylinder 2C, which are closer to the intake collecting portion 6, are separated from each other due to the large distance from the intake port 3. The independent intake passages 5a, 5b, 5c, and the inside of the substantially intermediate portion of the second curved portion 23, which are closer to each other from the intake port 3, communicate with each other.
The communication passage 46 can be easily provided at a position having the same length from the intake port 3 of 5d.

Further, as described above, the rotary valve 41
The outer side of the substantially intermediate portion of the first curved portion 22 in each independent intake passage 5a, 5d of the first cylinder 2a and the fourth cylinder 1J2d which are far from
Each independent intake passage 5a extends in the cylinder row direction between the independent intake passages 5b and 5c of the third cylinder 2c and the inside of the substantially intermediate portion of the second curved portion 23.

5b, 5c, and 5d are the respective independent intake passages 5a, 5b +
The rotary valve 41 orthogonal to 5 c * 5 d forms one rigid body, and the independent intake passage 5 a
, 5b, 5c, and 5d can be similarly increased in overall rigidity.

Further, FIGS. 6 and 7 show a third embodiment, which is also applied to an in-line four-cylinder engine 1.

That is, in this embodiment, the intake air collecting section 6 is located above the engine 1 and at the center in the cylinder row direction, and the rotary valve 41 is arranged in a direction substantially perpendicular to the cylinder row direction. In addition, each independent intake passage 5a, 5
b, 5c, and 5d, the independent intake passages 5b of the second cylinder 2b and the third cylinder 2C are located close to the intake collecting portion 6.

5C, and approximately the middle of the second curved portion 23 in each independent intake passage 5a, 5d of the first cylinder 2a and fourth cylinder 2d, which are located far from the intake collecting part 6. The portion is shifted in the inward and outward directions when viewed from the cylinder row direction. Each independent intake passage 5b, 5c of the second cylinder 2b and third cylinder 2C close to the intake collecting portion 6
and the approximate middle portion of the second curved portion 23 of each independent intake passage 5a, 5d of the first cylinder 2a and the fourth cylinder 2d which are far from the intake collecting portion 6. A rotary valve 41 extending in a direction substantially perpendicular to the direction of the cylinder row is provided between them.

Therefore, in this embodiment, each independent intake passage 5a
5b, 5c, and 5d are provided above the engine and approximately at the center in the cylinder row direction, and the passage lengths from the intake port 3 of each independent intake passage 5a, 5b, 5c, and 5d are made equal. In order to increase the length, approximately the middle portion of the second curved portion 23 in each independent intake passage 5a, 5d of the first cylinder 2a and fourth cylinder 2d, which are located far from the intake collecting portion 6, is on the outside, which is far from the intake port 3.
Each independent intake passage 5b of the second cylinder 2b and the third cylinder 2c is located close to the intake collecting part 6.

Approximately middle portions of the first curved portion 22 at 5c are arranged on the inner side near the intake ports when viewed from the cylinder row direction, forming independent intake passages 5a and 5b.

The first and second curved portions 22 and 23 of 5c and 5d are shifted inwardly and outwardly from each other, and the first cylinder 2 is far away from the intake collecting portion 6.
a substantially intermediate portion of the second curved portion 23 in each independent intake passage 5a, 5d of the fourth cylinder 2d, and each independent intake passage 5b of the second cylinder 2b and third cylinder 2c close to the intake collecting portion 6; A rotary valve 41 that extends in a direction perpendicular to the direction of the cylinder row and connects and disconnects the independent intake passages 5a, 5b, 5c, and 5d with each other is provided between the first curved portion 22 and the substantially middle portion of the first curved portion 22 at the first curved portion 5c. ing.

As a result, the rotary valve 41 becomes closer to the independent intake passages 5a and 5d of the first cylinder 2a and the fourth cylinder 2d, which are far from the intake collecting portion 6, or the intake port 3. A substantially middle portion of the first curved portion 22 located on the inside, and a second cylinder 2b and a third cylinder 2c close to the intake collecting portion 6
The distance from the intake port 3 is large for each of the independent intake passages 5b and 5c. Each independent intake passage 5a communicates with a substantially middle portion of the second curved portion 23 located on the outside.

The communication passages 46 can be easily provided at positions of equal length from the intake ports 3 of 5b, 5c, and 5d.

Further, as described above, the rotary valve 41
Approximately intermediate portions of the first curved portions 22 in the independent intake passages 5a and 5d of the first cylinder 2a and the fourth cylinder 2d, which are far from the air, and the second cylinder 2b and the third cylinder 2c, which are near the intake collecting portion 6. The independent intake passages 5g, 5b are provided to extend in the cylinder row direction between the substantially intermediate portion of the second curved portion 23 in each of the independent intake passages 5b, 5c.

5c, 5d are the respective independent intake passages 5a, 5b,
The rotary valve 41 orthogonal to 5c and 5d forms one rigid body, and the independent intake passages 5a, 5b, 5c
, 5a as a whole can be increased in rigidity and strength.

In the third embodiment, the rotary valve 41 is arranged extending in a substantially horizontal direction, but as shown in FIG. 51 into the intake air collection section 6, in which case each independent intake passage 5a, 5b
, 5c, and 5d are communicated with each other, the intake air in the intake air gathering portion 6 is supplied into the communication path 46 through the communication pipe 51, thereby achieving higher output. Moreover, each independent intake passage 5a,
5b, 5c, 5d are the respective independent intake passages 5a, 5b, 5
The rotary valve 41 that is orthogonal to the air intake passages 5a, 5d, and the communication pipe 51 connected to the intake air collecting portion 6 form a substantially triangular rigid body, which makes the overall rigidity and strength of the independent air intake passages 5a, 5b, 5c, and 5a more effective. can be improved.

Further, each of the above embodiments is an example applied to an in-line four-cylinder engine 1, but it can also be applied to an in-line engine having a plurality of cylinders. For example, in the case of an in-line 6-cylinder engine, the cylinders located far from and near the intake collecting section are divided into three cylinders each, and the curved portion of each independent intake passage for each of these three cylinders is viewed from the cylinder row direction. In addition to displacing the cylinders to far or near positions, the cylinders are divided into two cylinders each, and the curved portions of the independent intake passages for each of these two cylinders are shifted to far, near, or intermediate positions when viewed from the direction of the cylinder row. It is also possible to do so.

(Effects of the Invention) As described above, according to the invention according to claim (1), the cylinders are shifted inwardly and outwardly from each other when viewed from the direction of the cylinder row so that they are gathered above the engine. A communication path extending in the direction of the air section row so that the curved part located on the outside and the curved part located on the inside are brought closer to each other by the distance from the intake port and separated by the distance from the intake port by the short distance. A communication passage can be provided extending in the direction of the cylinder row at a position having the same length from the intake port of each independent intake passage. In addition, each independent intake passage becomes one rigid body due to the communicating passage substantially orthogonal to each independent intake passage, and the rigidity and strength of the entire independent intake passage can be increased.

Further, according to the invention according to claim (2), the positions are shifted from each other when viewed from the cylinder row direction so that they are gathered above the engine and on the blade side in the cylinder row direction. The curved portion located on the outside and the curved portion located on the inside are provided with a communication path extending in the direction of the cylinder row so that the curved portion located on the outside and the curved portion located on the inside are brought closer to each other as the distance from the intake port is greater and separated as much as the distance from the intake port is short. It is possible to provide communication passages that communicate with each other and extend in the direction of the cylinder row at equal length positions from the intake port of each independent intake passage. In addition, each independent intake passage becomes one rigid body due to the communicating passage substantially orthogonal to each independent intake passage, and the rigidity and strength of the entire independent intake passage can be increased.

Further, according to the invention according to claim (3), the curved portions located above the engine and approximately at the center in the direction of the cylinder row (-) are located at different positions from each other when viewed from the direction of the cylinder row so as to be clustered. and the curved portion located on the inner side are brought closer to each other by the distance from the intake port and separated by the distance from the intake port by the distance, and communicate with each other by a communication lens extending in the direction of the cylinder row. It is possible to provide communication passages extending in the direction of the cylinder rows at equal length positions from the intake ports of the independent intake passages.Moreover, each independent intake passage can be connected to a It becomes a rigid body and can increase the rigidity and strength of the entire independent intake passage.

Further, according to the invention according to claim (4), the positions are shifted from each other when viewed from the cylinder row direction so that they are gathered above the engine and approximately at the center in the cylinder row direction. The curved portion located on the outside and the curved portion located on the inside are arranged perpendicularly to the direction of the cylinder row so that the curved portion located on the outside and the curved portion located on the inside are brought closer to each other as the distance from the intake port is longer and separated as much as the distance from the intake port is short. The communication passages can be provided at positions having the same length from the intake port of each independent intake passage and perpendicular to the direction of the cylinder row. In addition, each independent intake passage becomes one rigid body due to the communicating passage substantially orthogonal to each independent intake passage, and the rigidity and strength of the entire independent intake passage can be increased.

Furthermore, according to the invention according to claim (5), since the rotary valve is provided inside the communication passage, the space required for providing the rotary valve can be made compact.

[Brief explanation of drawings]

1 to 3 show a first embodiment of the present invention.
2 is a plan view of the engine and the intake system, FIG. 2 is a front view related to FIG. 1, and FIG. 3 is an explanatory diagram showing the state of communication of each independent intake passage with the intake collecting section. 4 and 5 show the second embodiment, and FIG. 4 is a diagram equivalent to FIG.
FIG. 5 is a side view related to FIG. 4. 6 and 7 show the third embodiment, with FIG. 6 being a diagram corresponding to FIG. 2, and FIG. 7 being a diagram corresponding to FIG. 5. Further, FIG. 8 is a diagram corresponding to FIG. 5 showing a modified example. 1... Engine 2a-2d... Cylinder 5a-5d... Independent intake passage 6... Intake gathering part (collecting part) 22.23... Curved part 41... Rotary valve 46... Communication path and 1 other person

Claims (5)

[Claims] (1) An engine having a plurality of cylinders is provided with independent intake passages that communicate with each cylinder from one side of the engine, and each independent intake passage is curved and then its upstream ends are gathered in one place. In the engine intake system, the curved portions of each of the independent intake passages are offset from each other inwardly and outwardly when viewed from the direction of the cylinder row, and there is a gap between the curved portion located on the outside and the curved portion located on the inside. An intake system for an engine, characterized in that a communication passage is provided that extends in the direction of a cylinder row and allows independent intake passages to communicate with each other. (2) The engine intake system according to claim 1, wherein the gathering portion at the upstream end of each independent intake passage is located above the engine and on one side in the cylinder row direction. (3) The engine intake system according to claim 1, wherein the gathering portion at the upstream end of each independent intake passage is located above the engine and approximately at the center in the cylinder row direction. (4) An engine having a plurality of cylinders is provided with an independent intake passage that communicates with each cylinder from one side of the engine, and each independent intake passage is curved so that its upstream end is above the engine and in the direction of the cylinder row. In an engine intake system configured to gather at one location approximately in the center, the curved portions of the independent intake passages are offset from each other inwardly and outwardly when viewed from the cylinder row direction, and the curved portions located on the outside; An intake system for an engine, characterized in that a communication passage is provided between the curved part located on the inside and extends in a direction substantially perpendicular to the direction of the cylinder row, and allows the independent intake passages to communicate with each other. (5) The engine according to claim (1) or claim (4), wherein the communication passage has a rotary valve therein that controls communication between the communication passage and each independent intake passage and its interruption by rotation. intake device.