JP2649371B2 - Engine intake system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake device for an engine that performs supercharging by utilizing natural vibration of an intake system.

(Prior Art) Conventionally, an intake device that uses a pressure fluctuation generated in an intake passage between cylinders of a multi-cylinder engine to increase a pressure in an intake port portion in the latter half of an intake stroke to obtain a supercharging effect has been proposed. Various proposals have been made. One of the dynamic effects of this intake is inertial supercharging. In the inertial supercharging, a negative pressure wave from a cylinder in an intake stroke is inverted to a positive pressure wave by an intake expansion section, and supercharging is performed by an intake pushing action by the positive pressure wave.

As another thing of this dynamic effect of intake, Japanese Patent Publication No. 60-14
As shown in Japanese Patent Publication No. 169, there is resonance supercharging. This resonance supercharging is caused by the first cylinder in which the intake strokes are not adjacent to each other.
The cylinder group is divided into a cylinder group and a second cylinder group. Each cylinder of the first cylinder group is communicated with the first collecting passage via a branch intake pipe, and each cylinder of the second cylinder group is respectively divided via a branch intake pipe. It is communicated with the second collecting passage. The two collecting passages are connected to a common collecting part via independent resonance tubes. With such a configuration, the air column in the resonance pipe is vibrated due to the pressure wave generated by the periodic opening and closing of the intake port, and the vibration in the resonance pipe is caused by the first and second vibrations.
The air in the collecting passage and in the branch intake pipe are vibrated. Then, when the resonance of the vibration occurs, the amplitude of the pressure vibration becomes maximum, and a large supercharging is performed.

(Problems to be Solved by the Invention) On the other hand, in an in-line four-cylinder engine, 1-4 cylinders and 2 cylinders
The intake system is divided into two by three cylinders, and a collective passage for 1-4 cylinders and a collective passage for 2-3 cylinders are provided. It is conceivable to obtain a high resonance supercharging effect in a state in which a resonance intake passage having no air intake is formed and the attenuation of the pressure wave by the intake enlargement portion is eliminated.

In order to provide such an intake device, it is common to set an independent intake passage directly connected to each cylinder to be relatively long so as to obtain an inertia effect in a practical range. On the other hand, since the length of the independent intake passage becomes an obstacle, in the present invention, while the length of the independent intake passage is reduced, the intake dynamic effect is obtained by optimizing the length of the upstream collecting passage and the like. Such a resonance intake passage is set to constitute a compact intake system.

Further, when a compact intake system is configured with the inline four-cylinder engine as described above, if the four cylinders are directly assembled, the intake pressure oscillation is smoothed due to the overlap and the dynamic effect cannot be sufficiently utilized. Although the intake system is divided into two by the 1-4 cylinder and the 2-3 cylinder, if the intake passage is connected to each cylinder as it is in response to the shortened intake passage, the intake to the 1-4 cylinders on both sides is made. The intake passage length for the 2-3 cylinders on the center side is shorter than the passage length,
Since the length of the intake system for each cylinder is non-uniform, the natural frequency corresponding to each cylinder is different, and the volume efficiency due to the resonance effect is non-uniform. Along with this, there are problems such as an increase in output loss and a decrease in knocking resistance due to the occurrence of engine vibration and emission measures caused by the cylinder difference in the air-fuel ratio being set corresponding to the cylinder with the worst conditions. .

Furthermore, since two collecting passages are formed in the intake manifold, when the intake manifold is attached to the cylinder head due to its arrangement, there is a possibility that the intake manifold may interfere with a tool and impair attachment.

Therefore, in view of the above circumstances, the present invention reduces the inter-cylinder difference by equalizing the length of the intake system for each cylinder to obtain a high supercharging effect by configuring a compact intake system without an intake expansion section, An object of the present invention is to provide an intake device for an engine in which volume efficiency is equalized and mountability of a cylinder head is ensured.

(Means for Solving the Problems) In order to achieve the above object, an intake device of the present invention is an intake device for a four-cylinder engine configured with a resonance intake passage without an intake intake portion, wherein an intake port of a first cylinder is provided. And a first collective passage extending and communicating the intake port of the fourth cylinder in the cylinder arrangement direction and a second collective passage extending and communicating the intake port of the second cylinder and the intake port of the third cylinder in the cylinder arrangement direction. Prepared,
A first intake supply passage and a second intake supply passage for supplying intake air to the first and second collective passages, respectively, wherein the first collective passage is disposed outside the second collective passage when viewed from the side of the engine.
An intake supply passage is communicated with each of the collective passages, an upstream opening of the first intake supply passage is set at the same height as the first collective passage, and the second intake supply passage is curved upward or downward halfway, The upstream opening is formed so as to be set at one of the upper and lower sides of the upstream opening of the first intake supply passage.

(Operation) In the intake device for an engine as described above, the first collective passage extending from the side of the engine to the intake port of the 1-4 cylinder and extending and communicating in the cylinder arrangement direction is connected to the intake port of the 2-3 cylinder. While being arranged outside the second collective passage extending and communicating in the arrangement direction, the upstream opening of the first intake supply passage for supplying intake air to the first collective passage is set at the same height as the first collective passage, A second intake supply passage that supplies intake air to the second collective passage is curved upward or downward in the middle of the second intake supply passage, and its upstream opening is set to one of the upper and lower sides of the upstream opening of the first intake supply passage; By making the length of the intake passage of the second intake supply passage for the three cylinders longer than that of the first intake supply passage, the difference in length between the cylinder groups is reduced, the volume efficiency is equalized, and the resonance effect can be used effectively, Reduction of engine vibration and emission set loss, In addition to improving knock resistance, the intake device is compactly configured to obtain good attachment to the cylinder head.

(Embodiments) Each embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 shows a schematic passage configuration of an intake device of this embodiment.

First to fourth cylinders 1a to 1d are arranged in series in the engine body 1, and an intake passage 3 for supplying intake air to each of the cylinders 1a to 1d.
Is a first group of independent intake passages 4a, 4d to 1-4 cylinders
A collective passage 5 and a second collective passage 6 for collecting the independent intake passages 4b and 4c to the 2-3 cylinders are provided, and an upstream first intake supply passage 7 is connected to the first collective passage 5, The second intake passage 8 on the upstream side is connected to the two collecting passages 6. The first and second intake supply passages 7 and 8 are joined at a branch portion 9 serving as a pressure reversal portion on the upstream side, and further connected to an intake air amount sensor 10 and an air cleaner 11 on the upstream side to provide a resonance intake without an intake enlargement portion. The passage 3 is configured. The two intake supply passages 7,
In the middle of 8, throttle valves 12, 13 are interposed.

In this basic structure, each of the independent intake passages 4a to 4d is formed to be short, and a large intake section such as a surge tank is eliminated to constitute a compact intake system.
The attenuation of the pressure wave in the volume part in the propagation of the pressure wave is reduced to enhance the output improvement effect at the tuning point.

The specific structure is shown in FIG. 2 and FIG. The engine body 1 is composed of a cylinder block 15, a cylinder head 16 fastened to an upper portion thereof, and an oil pan 17 at a lower portion.
A head cover 18 is mounted on an upper portion of the cylinder head 16.

On the side surface of the cylinder head 16, the first to fourth cylinders 1a to 1a
The intake ports 2a to 2d of 1d are opened, and the intake ports 2a to 2d are opened.
An intake manifold 20 is connected to 2d. In the intake manifold 20, independent intake passages 4a to 4d communicating with the intake ports 2a to 2d of the cylinders 1a to 1d are provided on a downstream flange 20a attached to the cylinder head 16.
A first collecting passage 5 for collecting the independent intake passage 4a of the first cylinder 1a and the independent intake passage 4d of the fourth cylinder 1d;
A second collecting passage 6 is provided for collecting the independent intake passage 4b of the first cylinder 1b and the independent intake passage 4c of the third cylinder 1c.

The second collecting passage 6 is formed to be short in a curved shape to the side of the opening of the intake ports 2b and 2c, and the first collecting passage 5 is at the same height as the second collecting passage 6 and is similarly formed on the outside thereof. It is curved and formed long. In addition, the first collecting passage 5
The first intake supply passage 7 on the upstream side is connected to the curved portion on the fourth cylinder 1d side, and the first intake supply passage 7 is at the same height as the first collective passage 5, that is, on the side of the intake opening, It is formed to extend to the left (referred to as rear) in the cylinder arrangement direction, and opens to the upstream flange 20b. On the other hand, the second collecting passage 6
A second intake supply passage 8 on the upstream side is connected to the lower part of the center, and the second intake supply passage 8 is curved downward and outward from the second collecting passage 6 to be lower than the first intake supply passage 7. From the upstream flange 20b.
It is open up and down.

The intake manifold 20 is connected to a downstream flange.
The boss 20c formed above and below the 20a is mounted on the cylinder head 16 by applying a mounting bolt. The fastening of the mounting boss portion 20c is performed with good workability by using tools from the upper and lower sides of both the collective passages 5, 6 and the first intake supply passage 7.

In the above intake passage structure, the upstream flange
The length of the first intake supply passage 7 and the first collective passage 5 from 20b to the first cylinder 1a, the length of the second cylinder 1b and the third
The curved shape of the second intake supply passage 8 leading to the cylinder 1c and the second
The passage length of the collecting passage 6 is set to be substantially equal. In particular, the second intake supply passage 8 is connected to the center of the second collective passage 6 so that the passage lengths to the second and third cylinders 1b and 1c are equal.

Note that, for the fourth cylinder 1d, the actual intake distance is shorter than the other cylinders 1b to 1d due to the relationship with the connection position of the first intake supply passage 7 with respect to the first collective passage 5. 1
In order to flow into the fourth cylinder 1d with respect to the flow of air in the intake supply passage 7, the angle changes abruptly, so that resistance to the flow into the fourth cylinder 1d occurs, and the air smoothly flows into the first cylinder 1a. In this way, the volume efficiency is equalized by reducing the difference between the inflow amounts of the 1-4 cylinders. The fourth cylinder 1d
The connection between the first collective passage 5 and the first intake supply passage 7 may be made at right angles without being curved as shown in FIG. 3, but the radius R of the connecting portion to the fourth cylinder 1d is Is made smaller on the upstream side to provide resistance.

According to the intake device of the present example, it is possible to reduce the difference in the passage length between the cylinders and to secure the output improving effect by the good dynamic effect in each of the cylinders 1a to 1d by the resonance intake passage 3 having no intake expansion portion. it can. That is, the intake ports of each cylinder 1a to 1d
The negative pressure waves generated in 2a to 2d propagate upstream through the respective collective passages 5, 6 and the intake supply passages 7, 8 and are reversed at the confluence, and a positive pressure acts at the end of the intake stroke, so that the intake port pressure is reduced. Rises to obtain a supercharging effect, but since there is no intake expansion part in the propagation of this pressure wave, the attenuation of the pressure wave is small and the dynamic effect is increased by the high pressure amplitude at the tuning point, and Equalize the passage length to reduce the difference in volume efficiency due to the dynamic effect of each cylinder, reduce vibration due to torque difference between cylinders, reduce emission set loss due to air-fuel ratio difference, and improve knock resistance. Can be done.

Although not specifically shown in the above embodiment, a throttle body having a throttle valve is connected to the upstream flange 20b of the intake manifold 20 (see FIG. 5). The throttle body is disposed, for example, above the cylinder head 16, and can reduce the overall height of the engine as compared with this structure.

Embodiment 2 The front structure of the engine of this embodiment is shown in FIG. In this example, the upstream second intake supply passage 22 connected to the second collecting passage 6 for the second cylinder 1b and the third cylinder 1c is connected from above. The connection position is a position from the center toward the third cylinder 1c. Other configurations are the same as in the previous example, and the same structures are denoted by the same reference numerals.

The reason why the second intake supply passage 22 is connected to the second collecting passage 6 from the upper side or the lower side as in the previous example is to avoid interference with the surrounding auxiliary equipment in accordance with the positional relationship with the peripheral accessories. There is no difference in obtaining a dynamic effect.

Embodiment 3 FIG. 5 shows a schematic plan configuration of the engine of this embodiment. In this example, the second intake supply passage 22 connected to the second collective passage 6 for the second cylinder 1b and the third cylinder 1c is configured to be connected from above, and the first and second intake supply passages are connected.
The portion near the upstream flange 20b of the upstream end portion of 7,22 is
It is bent toward the engine body 1. The throttle body 23 is connected to the upstream flange 20b,
The intake passage 24 further upstream from the throttle body 23 is
A rear portion of the engine body 1 is formed in a substantially inverted S-shape and is connected to the intake air amount sensor 10. The passages for the first and fourth cylinders arranged vertically just before the intake air amount sensor 10 are provided. The passages for the second and third cylinders are configured to merge.

In addition, a passage indicated by a chain line is a first collective passage 5 and a second
5 shows an example of forming a communication path 25 connecting the downstream ends of the collective path 6.

Fourth Embodiment This embodiment is shown in FIGS. 6 and 7, and the basic structure of the intake passage 3 is the same as that of the first embodiment. And
A downstream end of the first collecting passage 5 that collects the independent intake passages 4a and 4d of the 1-4 cylinders and a downstream end of the second collecting passage 6 that collects the independent intake passages 4b and 4c of the 2-3 cylinder communicate with each other. Communicated by 27. The communication passage 27 is connected to the first collective passage 5 from the cylinder arrangement direction (front), and is bent inward and upward in a U-shape from the connection portion for the first collective passage 5 in the cylinder arrangement direction. Is formed to extend rearward, and the second
It is connected to the downstream side of the collecting passage 6. Other configurations are the same as those of the first embodiment, and the same components are denoted by the same reference numerals.

In this example, the connection of the communication passage 27 increases the volume of the pressure propagation by the communication between the first collecting passage 5 and the second collecting passage 6, and the tuning point for obtaining the resonance effect shifts to the high engine speed side. I do. The downstream portion of the intake passage is a communication passage 27.
And the cylinder 1a is located downstream of the intake like the first cylinder 1a and the second cylinder 1b, and the intake amount tends to decrease under the influence of the lean air due to the intake of the upstream cylinders 1c and 1d. , 1b, the intake air flows through the communication passage 27, and the intake air amount can be made uniform.

When the pressure wave generated in the first collecting passage 5 propagates to the pressure inverting portion 9 on the upstream side, for example, the pressure propagation by the communication passage 27 as described above propagates through the first collecting passage 5 to the upstream side as it is. In addition to the above, the communication passage from the first collective passage 5
When the second intake passage 8 is connected to the second collecting passage 6 from below, the communication passage 27 is connected to the second collecting passage 6 from above. The pressure wave transmitted from the communication passage 27 to the second collective passage 6 propagates to the second intake supply passage 8 on the upstream side as it is,
This has the effect of reducing the attenuation of the pressure wave passing through the communication passage 27. That is, the communication path 27 is connected so that the propagation direction of the pressure wave propagating through the communication path 27 is not changed as much as possible, and the attenuation of the pressure wave is reduced to obtain a high supercharging effect. It is changed according to the shape of the intake manifold 20.

Although not adopted in this example, an on-off valve that opens and closes in accordance with the engine speed is interposed in the communication passage 27, and the tuning point is set to the low speed side in the closed state, and opened to shift to the high speed side. A plurality of tuning points may be used to expand the torque increase range.

Embodiment 5 This embodiment is shown in FIG. 8 and FIG. 9, in which a communication passage 28 connecting the downstream side of the first collecting passage 5 for the 1-4 cylinder and the second collecting passage 6 for the 2-3 cylinder is taken in. Manifold 20
This is an example in which it is formed inside.

At first, the intake manifold 20 includes a first collecting passage 5 that collects the independent intake passages 4a and 4d of 1-4 cylinders and a second collecting passage 6 that collects the independent intake passages 4b and 4c of 2-3 cylinders. ,
The first cylinder 1a and the fourth cylinder 1d are formed so as to be in communication with each other, and the communication on the fourth cylinder 1d is closed by the formation of the closing member 29, while the communication on the first cylinder 1a is provided with an on-off valve. The communication path 28 is provided with a communication path 30 interposed therebetween so as to openably and closably communicate the downstream side of the first collection path 5 and the downstream side of the second collection path 6. The on-off valve 30 is opened and closed by an actuator 31 so as to close at a low speed and open at a high speed according to the engine speed.

In this example, the volume of the communication passage 28 can be reduced, and when the on-off valve 30 is closed, the on-off valve 30
The attenuation of the pressure wave due to the formation of the communication path 28 is small, and the output improving effect at the tuning point is large. Further, since the volume of the communication passage 28 is small, responsiveness is good and a more compact intake system can be configured.

When the on-off valve 30 is closed, the intake downstream cylinder 1
A small-diameter always-open communication passage may be provided in parallel in order to ensure the introduction of intake air to the a and 1b through the communication passage 28.

Embodiment 6 This embodiment is shown in FIGS. 10 and 11 and relates to a structure for installing a communication passage.

Similarly to the second embodiment, the first intake supply passage 7 is connected from the first collective passage 5 for 1-4 cylinders in the cylinder arrangement direction,
A second intake supply passage 22 is connected in the cylinder arrangement direction so as to curve upward from the second collective passage 6 for 2-3 cylinders.

A communication passage 34 that communicates the downstream end of the first collective passage 5 and the second collective passage 6 extends upward from the upper portion of the downstream end of the first collective passage 5 located below, and , It bends and extends in the cylinder arrangement direction, further bends forward in a U-shape, bends downward, is connected to the downstream end of the second collecting passage 6 from above, and has a predetermined length. Other configurations are the same as those of the first embodiment, and the same structures are denoted by the same reference numerals.

In the present example, the communication path 34 is formed to be long in relation to the speed range in which the tuning point is to be obtained, and the communication path 34 is mainly for supplying the pressure wave of the intake air. Since the amount of air flowing through the communication passage 34 is small, foreign matters such as oil and fuel mixed into the intake air easily accumulate in the communication passage 34, and in order to prevent a decrease in the passage area and a change in dynamic characteristics, It is arranged above the first and second collecting passages 5, 6 so as to prevent foreign matters and the like accumulated at the bottom of the collecting passage from flowing in.

Also, in the communication passages 27 and 28 shown in the fourth and fifth embodiments, it is preferable that at least the bottom of the communication passage is formed to be higher than the bottom of the collecting passages 5 and 6.

Embodiment 7 This embodiment is shown in FIGS. 12 to 14, and is an example in which the communication passage is formed compactly when the communication passage is formed long in terms of its performance.

The communication passage 36 connected to the downstream end of the first collecting passage 5 from above extends upward, then curves toward the cylinder head 16 at the upper part of the cylinder head 16 and extends into the head cover 18. It is arranged along the outer periphery, protrudes laterally from the head cover 18 above the second collecting passage 6, curves downward, and is connected to the downstream end of the second collecting passage 6 from above. It is. Other configurations are the same as in the previous example, and the same structures are denoted by the same reference numerals.

In the structure of the present example, the communication path 36 can be disposed compactly by utilizing the extra space in the head cover 18.

Eighth Embodiment This embodiment is shown in FIGS. 15 and 16 and is an example in which a long communication path is arranged compactly as in the previous example.

The communication passage 38 connected from above to the downstream end of the first collecting passage 5 extends upward and then extends forward in the cylinder arrangement direction,
It bends at the front of the cylinder head 16 and extends along the front surface of the cylinder head 16, curves in a U-shape on the opposite side, then further bends in the cylinder arrangement direction, and curves downward above the second collecting passage 6. And is connected to the downstream end of the second collecting passage 6 from above. The communication passage 38 on the front side of the cylinder head 16 is covered by a timing bell cover (not shown). Other configurations are the same as in the previous example, and the same structures are denoted by the same reference numerals.

In the structure of the present example, the communication path 38 can be disposed compactly by utilizing the extra space in the belt cover on the front side of the cylinder head 16.

Ninth Embodiment This embodiment is shown in FIG. 17 and is an example in which the natural frequencies of the cylinders 1a to 1d are made uniform.

The basic structure is the same as that of FIG.
The first to fourth cylinders 1a to 1d are arranged in series, and an intake passage 3 for supplying intake air to each of the cylinders 1a to 1d has a first intake passage 4a and 4d for collecting independent intake passages 4a and 4d to the 1-4 cylinders. Meeting passages 5 and 2
And a second collecting passage 6 for collecting the independent intake passages 4b and 4c to the third cylinder, and a first intake supply passage 7 on the upstream side of the first collecting passage 5 is provided on the upstream side of the second collecting passage 6. The second intake supply passages 8 are respectively connected. The first collecting passage 5 is disposed outside the second collecting passage 6, and the second intake supply passage 8 is connected to the second collecting passage 6 from below or above.

The first and second intake supply passages 7 and 8 are joined at a branch portion 9 serving as a pressure reversal portion on the upstream side, and further connected to an intake air amount sensor 10 and an air cleaner 11 on the upstream side to provide a resonance intake without an intake enlargement portion. The passage 3 is formed. Throttle valves 12, 13 are interposed in the middle of the intake passages 7, 8.
In addition, a communication passage 40 that connects the downstream end of the first collecting passage 5 and the downstream end of the second collecting passage 6 to each other is connected, and an on-off valve 41 that opens at high speed is provided in the middle of the communication passage 40. Have been.

Further, a first auxiliary communication passage 42 that connects the independent intake passage 4a to the first cylinder 1a and the independent intake passage 4b to the second cylinder 1b, and an independent intake passage 4a and a third
A second auxiliary communication passage 43 that communicates the independent intake passage 4c with the cylinder 1c is provided.

In the intake system of the present example, the length of the independent intake passages 4a to 4d for each of the cylinders 1a to 1d is set to be short, so that the inertial effect is not obtained in the engine rotation range by itself, and a branch portion serving as a pressure reversal portion is provided. Since the passage length from the cylinder 9 becomes shorter in the fourth cylinder 1d, the pressure reversal at the branch 9 is prevented by the intake preceding cylinder (1).
In the case of utilizing the positive pressure generated from the latter half of the intake stroke (in the order of -3-4-2 cylinders), the pressure propagation path from the 3 → 4 cylinder and the 4 → 2 cylinder is shortened and becomes uneven. ing.

That is, by forming the first and second auxiliary communication passages 42 and 43, the equivalent pipe length in the pressure propagation to the 1 → 3 cylinder and the 2 → 1 cylinder is shortened, and the intake system for each of the cylinders 1a to 1d is substantially reduced. This is to equalize the natural frequency. At this time, the diameters and lengths of the first and second auxiliary communication passages 42 and 43 are set according to the tuning engine speed, the shape of each part, and the like, but detailed calculation formulas are omitted.

By equalizing the natural frequencies of the cylinders 1a to 1d as described above, each cylinder in a compact intake system without an intake expansion section
By making the volume efficiencies 1a to 1d uniform, it is possible to further reduce engine vibration, reduce emission set loss, and improve knock resistance.

Embodiment 10 This embodiment is shown in FIG. 18 and is a modification for making the natural frequencies of the cylinders 1a to 1d uniform.

This example is different from the ninth embodiment in that the number of auxiliary communication passages is two, but one auxiliary communication passage 45 is divided into the independent intake passage 4a of the first cylinder 1a and the second collective passage 6 for 2-3 cylinders. To obtain a similar equalization. Others are formed similarly to the previous example.

In each of the above embodiments, in order to equalize the natural frequency of each of the cylinders 1a to 1d, an independent intake passage for each of the cylinders is used.
Whether the diameter or length of 4a-4d is adjusted to increase the equivalent pipe length for the fourth cylinder, or the opening / closing timing of the intake valve is adjusted to reduce the intake valve opening angle of the fourth cylinder, The diameter of the passage for the fourth cylinder may be set to be small by adjusting the diameter of the collective passage near the intake section to each cylinder.

(Effect of the Invention) According to the present invention as described above, the first collective passage extending from the side of the engine to the intake port of the 1-4 cylinder and extending and communicating with the intake port of the cylinder is viewed from the engine side. Is arranged outside the second collective passage extending in the cylinder arrangement direction and communicating therewith, and the upstream opening of the first intake supply passage for supplying intake air to the first collective passage is set at the same height as the first collective passage. On the other hand, the middle of the second intake supply passage for supplying intake air to the second collective passage is curved upward or downward, and the upstream opening thereof is set at one of the upper and lower sides of the upstream opening of the first intake supply passage. Thereby, the length of the intake passage of the second intake supply passage for the 2-3 cylinders can be made longer than that of the first intake supply passage, the difference in length between the cylinder groups is reduced, the volume efficiency is equalized, and the resonance effect is effective. Available for engine vibration, emission set In addition to reducing the loss and improving the knock resistance, the intake device can be configured compactly, and good attachment to the cylinder head can be ensured.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an intake device of an engine according to a first embodiment of the present invention, FIG. 2 is a front view showing a specific engine structure of the first embodiment, and FIG. FIG. 4 is a front view of the engine according to the second embodiment, FIG. 5 is a plan view of the main part of an intake passage portion of the engine according to the third embodiment, FIG. FIG. 7 is a plan view of a main part of an intake passage portion of the engine in FIG. 8, FIG. 8 is a front view of the engine in the fifth embodiment, and FIG. 9 is an intake passage portion of the engine. FIG. 10 is a front view of the engine in the sixth embodiment, FIG. 11 is a sectional side view of the main part of the engine, FIG. 12 is a front view of the engine in the seventh embodiment, FIG. Fig. 13 is a side view of the engine, and Fig. 14 is a flat view of the head cover of the engine. FIG. 15, FIG. 15 is a front view of the engine in the eighth embodiment, FIG. 16 is a side view of the engine, FIG. 17 is a schematic configuration diagram of an intake device of the engine in the ninth embodiment, FIG. FIG. 16 is a schematic configuration diagram of an intake device for an engine in a tenth embodiment. DESCRIPTION OF SYMBOLS 1 ... Engine body, 1a-1d ... Cylinder 3, ... Intake passage, 4a-4d ... Independent intake passage, 5 ... First collective passage, 6
... Second collective passage, 7, 8, 22... Intake supply passage, 16... Cylinder head, 20... Intake manifold.

Claims (7)

(57) [Claims] An intake device for a four-cylinder engine comprising a resonance intake passage having no intake expansion portion, wherein an intake port of a first cylinder and an intake port of a fourth cylinder extend and communicate with each other in a cylinder arrangement direction. A first collective passage, a second collective passage extending in the cylinder arrangement direction and communicating the intake port of the second cylinder and the intake port of the third cylinder, and the first collective passage is a second collective passage viewed from the side of the engine. A first intake supply passage and a second intake supply passage which are arranged outside the collective passage and supply intake air to the first collective passage and the second collective passage, respectively, are communicated with each collective passage; The upstream opening is set at the same height as the first collecting passage, and the second intake supply passage is curved upward or downward in the middle, and the upstream opening is located above or below the upstream opening of the first intake supply passage. Characteristically set to one side The intake system of the engine. 2. The engine according to claim 1, wherein both the first intake supply passage and the second intake supply passage extend in the cylinder arrangement direction, and an upstream opening opens to the side of the engine body. Engine intake device. 3. The intake device for an engine according to claim 1, further comprising a communication passage that connects a downstream end of the first collecting passage and a downstream end of the second collecting passage to each other. 4. The intake system for an engine according to claim 3, wherein an on-off valve that opens and closes in response to a predetermined signal is provided in the communication path. 5. The intake system for an engine according to claim 3, further comprising an auxiliary communication passage for uniformizing a pressure propagation path between the cylinders. 6. The intake system for an engine according to claim 5, wherein two auxiliary communication paths are provided. 7. An intake system for an engine according to claim 3, wherein said communication passage is provided in a head cover.