JP2003193847A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To intensify a tumble stream when a shutter valve is closed and to reduce intake flow resistance when the shutter valve is opened. <P>SOLUTION: An inner wall in a part P3 which is not closed by the shutter valve 51 in first branched passages 11-14 on the upstream side and an intake port 8 on the downstream side across the shutter valve 51 is formed like a substantially straight line. An inner wall in a part closed by the shutter valve 51 in the first branched passages 11-14 on the upstream side and the intake port 8 on the downstream side across the shutter valve 51 is formed so as to swell in the radial direction at an arrangement position of the shutter valve 51. A cross sectional area of a flow passage of the first branched passages 11-14, at the arrangement position of the shutter valve 51 is formed to be larger than a cross sectional area of a flow passage on the upstream side and the downstream side of the shutter valve 51. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for an engine that produces a tumble flow in a cylinder.

[0002]

2. Description of the Related Art Conventionally, a shutter valve is provided in the vicinity of a downstream end opening connected to an intake port in an independent intake passage for each cylinder to close a part of a flow passage section of the intake passage and A technique for strengthening the tumble flow generated in the above has been proposed (Japanese Patent Laid-Open No. 8-218881).

Further, there has been proposed a structure in which a large number of shutter valves are connected to each other and disposed near the downstream end opening of the intake passage (see Japanese Patent Laid-Open No. 8-240123).

[0004]

Due to the recent demand for both high output and low fuel consumption of an engine, it is necessary to strengthen the tumble flow generated in the cylinder. Further, since the intake passage needs to have a predetermined length or more in order to increase the intake air charging efficiency into the cylinder in the low speed operation state of the engine, the intake passage is curved downward from a higher position and is connected to the intake port. It will be composed. For this reason, the intake passage and the intake port cannot be laid out in a straight line, which becomes an intake flow resistance and hinders the generation of tumble.

The present invention has been made in view of the above problems, and an object thereof is to provide an intake system for an engine which can enhance the tumble flow when the shutter valve is closed and reduce the intake flow resistance when the shutter valve is opened. Is.

[0006]

In order to solve the above-mentioned problems and to achieve the object, an intake system for an engine according to the present invention is provided in an engine unit, and an intake port leading to a cylinder from an obliquely upper side and an obliquely upper direction. From the side to the intake port, and a shutter valve that is provided near the opening of the downstream end of the intake passage and closes a part of the flow passage cross section of the intake passage. In the intake device of the engine that generates the, the shutter valve and the inner walls of the upstream and downstream intake passages and intake ports of the intake valve that are not blocked by the shutter valve are formed in a substantially straight line, and the shutter valve and the upstream and downstream of the shutter valve. The inner wall of the portion of the intake passage and the intake port that is closed by the shutter valve is expanded in the radial direction at the position where the shutter valve is provided. Formed in the flow path cross-sectional area of the intake passage at the installation position of the shutter valve and greater than the upstream and downstream of the flow path cross-sectional area of the shutter valve.

Further, preferably, when viewed from one side in the cylinder row direction of the engine, an inclination angle of the intake passage in an obliquely upward direction is larger than an inclination angle of the intake port, and the inclination angle of the shutter valve is increased. An inner wall of an upper portion of the passage section of the intake passage that is not blocked by the shutter valve in the installation portion is formed in a substantially straight line, and the shutter valve of the passage section of the intake passage in the installation portion of the shutter valve is formed by the shutter valve. The inner wall of the lower portion to be closed is formed so as to bulge in the radial direction at the position where the shutter valve is arranged, and corresponds to the inner wall of the upper portion of the flow passage section of the intake passage of the shutter valve that is not closed by the shutter valve. I cut out a part.

Further, preferably, the intake port is branched from a collecting passage upstream thereof so as to communicate with each cylinder of the engine, the intake passage is extended from the collecting passage, and the collecting passage is arranged from an engine unit side. It is formed so as to be curved downward and to be curved from the side opposite to the engine unit of the collecting passage to the upper side of the collecting passage so as to surround the collecting passage.

Further, preferably, a valve guide for guiding the intake valve is provided by notching a portion corresponding to an inner wall of an upper portion of the flow passage section of the intake passage in the shutter valve which is not closed by the shutter valve. The inner wall of the upper portion of the intake port is formed flat in the section from the upstream to the downstream of the valve guide, and the flat portion narrows the flow passage area of the upper portion of the intake port where the valve guide is provided. ing.

Preferably, the intake port is branched into two and communicates with the inside of the cylinder, and the area of the flow passage downstream from the upstream end opening communicating with the intake passage in the intake port is narrowed. The cross section of the flow path up to the two intake ports is formed flat and rectangular in the upper part, the side face part and the lower part on the side between the two intake ports, and on the side between the two anti-intake ports which branch into the two. The side surface portion is formed in a round shape.

[0011]

As described above, according to the first aspect of the present invention, the shutter valve and the inner walls of the upstream and downstream intake passages and intake ports of the intake valve that are not blocked by the shutter valve are formed in a substantially linear shape. The shutter valve, the upstream and downstream intake passages, and the inner wall of the portion of the intake port that is closed by the shutter valve are formed so as to expand in the radial direction at the shutter valve installation position, and the intake passage at the shutter valve installation position The flow passage cross-sectional area of the shutter valve is made larger than the flow passage cross-sectional areas upstream and downstream of the shutter valve, so that the tumble flow is strengthened when the shutter valve is closed, while the intake flow resistance can be reduced when the shutter valve is opened. .

According to the second aspect of the present invention, when viewed from one side in the cylinder row direction of the engine, the angle of inclination of the intake passage obliquely upward is larger than the angle of inclination of the intake port, and the shutter valve The inner wall of the upper portion of the passage section of the intake passage that is not closed by the shutter valve is formed in a substantially linear shape, and is closed by the shutter valve of the passage section of the intake passage at the installation portion of The inner wall of the lower portion is formed so as to bulge in the radial direction at the position where the shutter valve is arranged, and the portion corresponding to the inner wall of the upper portion of the flow passage section of the intake passage of the shutter valve which is not blocked by the shutter valve is cut out. As a result, the tumble flow can be strengthened when the shutter valve is closed, while ensuring the intake passage length and improving the intake charging efficiency in the low speed operation state.

According to the third aspect of the present invention, the intake port is branched from the upstream collecting passage so as to communicate with each cylinder of the engine, and the intake passage is extended from the collecting passage.
The intake passage length is secured by curving from the engine unit side to the lower side of the collecting passage and curving from the engine unit side to the upper side of the collecting passage to surround the collecting passage. As a result, the tumble flow can be strengthened when the shutter valve is closed, while improving the intake charging efficiency in the low speed operation state.

According to the invention of claim 4, a valve guide for guiding the intake valve is formed by notching a portion corresponding to the inner wall of the upper portion of the flow passage cross section of the intake passage of the shutter valve which is not closed by the shutter valve. The inner wall of the upper portion of the intake port where is provided is formed flat in the section from the upstream to the downstream of the valve guide, and the flat portion narrows the flow passage area of the upper portion of the intake port where the valve guide is provided. By this, it is possible to suppress the attenuation of the flow due to the inner wall surface of the upper portion of the intake port.

According to the invention of claim 5, the number of intake ports is two.
The flow passage cross section from the upstream end opening communicating with the intake passage of the intake port to the portion where the flow passage area is narrowed down is divided into two. The upper part, the side part and the lower part are formed flat and rectangular in the inter-port side, and the side part is formed in the round shape in the anti-intake port side which is branched into two, so that the shutter is formed. When the valve is open, the intake flow velocity from the intake passage to each intake port is increased along the upper and lower parts of the flow passage cross section to ensure high output, and when the shutter valve is closed, the intake passage is opened from each intake port. It is possible to increase the intake flow velocity in the upper portion of the flow path cross section to strengthen the tumble flow and increase the intake charging efficiency.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The embodiment described below is an example of application to an intake device for an in-line four-cylinder engine for automobiles as a means for realizing the present invention, but the present invention is, for example, within a range not departing from the spirit of the invention. , The number of cylinders is not limited to 4 cylinders, V
The present invention can also be applied to a modified or modified version of the following embodiment so that it can be mounted on other engine types such as 6, V8, and horizontally opposed. [First Embodiment] First, an intake system for an engine according to a first embodiment of the present invention will be described.

In the following description, when viewed from the front of the engine of FIG. 1, the vertical direction of the plane of the drawing is the vertical direction of the vehicle body, the left-right direction is the vehicle width direction (cylinder row direction), the front-back direction is the front-back direction of the vehicle body, and similarly. In the plan view of the engine of FIG. 2, the front and back directions of the plane of the drawing are the vertical direction of the vehicle body, the left-right direction is the vehicle width direction (cylinder row direction), and the vertical direction is the vehicle front-back direction. One example is one horizontally placed in the width direction, but the present invention is not limited to this, and it goes without saying that the present invention is also applicable to one vertically placed in the front-rear direction of the vehicle body.

FIG. 1 is a front view of an engine air intake device of a first embodiment according to the present invention, FIG. 2 is a plan view of an engine air intake device of a first embodiment of the present invention, and FIG. 3 is related to the present invention. FIG. 4 is a right side view of the engine intake system of the first embodiment, and FIG. 4 is a left side view of the engine intake system of the first embodiment of the present invention, respectively, showing an in-line 4-cylinder engine 1 (hereinafter referred to as engine 1). The engine unit 2 has a cylinder block 2a and a cylinder head 2b, and four first to fourth cylinders 3A to 3D arranged in series in the cylinder block 2a from the right side to the left side of the drawing. And the cylinder head 2b defines an upper end portion of each of the cylinders 3A to 3D, and a top surface portion 3a having two intake ports 8 and two exhaust ports 9 communicating with the cylinders 3A to 3D is formed. Done There. Each intake port 8 is provided with an intake valve 5 that opens and closes a port opening 8a that communicates with each cylinder 3A to 3D, and a valve guide that operates coaxially with a tangent line that is in contact with the axis of the intake port 8 at the port opening 8a. You will be guided at 5a. Similar to each intake port 8, each exhaust port 9 is provided with an exhaust valve 6 that opens and closes a port opening 9a communicating with each cylinder 3A to 3D, and a tangent line that is in contact with the axis of the exhaust port 9 at the port opening 9a. It is guided by the valve guide 6a so as to operate coaxially with.

In each of the cylinders 3A to 3D, a combustion chamber is formed by the top surface portion 3a, the piston 4, two intake valves 5 and two exhaust valves 6. The intake port 8 has an upstream portion of 1
In the book, it branches toward two intake valves 5 on the way.
The engine unit 2 is provided with an intake device 7 for introducing intake air into each of the cylinders 3A to 3D on one front side in the front-rear direction of the vehicle body, and the intake air introduced from the intake device 7 is By opening the intake valve 5 via the intake port 8, the respective cylinders 3A to 3D have a predetermined timing (for example, 3
It is filled in the order of A → 3C → 3D → 3B). <Intake Device> Next, the intake device 7 will be described.

As shown in FIGS. 1 to 4, the intake device 7
Is an intake pipe 23, a surge tank (collecting passage) 10,
Four first branch passages 11 to 14 branched from the outer peripheral portion of the surge tank 10 and respectively connected to the intake ports 8 of the four cylinders 3A to 3D, and a first branched passage 11 branched from the outer peripheral portion of the surge tank 10 are provided. The second branch passages 15 to 18 communicating with the first branch passages 11 to 14 so as to short-circuit the first branch passages 11 to 14, the surge tank 10, and the first branch passages 11 to 14 or the second branch passage 15 And a rotary valve (variable intake mechanism) 20 capable of selectively changing a communication state with each other in accordance with an operating state of the engine. The surge tank 10 and the first and second branch passages 11 to 1
8 is integrally formed of a material such as synthetic resin.

The surge tank 10 is formed in a hollow cylindrical shape whose axis extends horizontally in the left-right direction, is arranged near one side of the engine unit 2 in the front-rear direction of the vehicle body, and has an intake pipe at the right end of the surge tank 10. A throttle body 24 is provided downstream of the intake pipe 23. The throttle body 24 has a built-in throttle valve 24a, and the opening degree of the throttle valve 24a changes according to the depression operation of an accelerator pedal or the operation of an electrically driven actuator, and the surge tank 10
The amount of intake air flowing in is adjusted. The length in the left-right direction of the surge tank 10 is formed to be shorter than the distance between the two intake ports 8 corresponding to the cylinders 3A and 3D at the left and right ends, respectively.

The first branch passages 11 to 14 are connected to the outer peripheral portion of the surge tank 10 at the first upstream end opening 11a to.
14a and the first pipe portions 11b to 11b extending in a straight line from the first upstream end openings 11a to 14a while extending obliquely upward to the engine unit 2 side and curving downward of the surge tank 10.
14b, second pipe portions 11c to 14c that linearly extend above the surge tank 10 while curving toward the engine unit 2 side below the surge tank 10, and bend toward the engine unit 2 side above the surge tank 10. To the intake port 8 that extends to the side of the engine 1
5 and the third pipe portions 11d to 14d connected to each other.

Further, the first pipe portions 11b to 14b that are curved from above the surge tank 10 and extend downward in the first branch passages 11 to 14 are formed so as to be arranged in a substantially planar shape in the cylinder row direction on the engine unit 2 side. Has been done.

Second pipe portions 11c to 14c extending upward from below the surge tank 10 in the first branch passages 11 to 14.
Are arranged in a substantially planar shape in the cylinder row direction on the side opposite to the engine unit 2 and are located at both ends of the cylinder row in the cylinder row direction.
The lower end positions P1 of the c and 14c are the second pipe portions 12c and 13c located at the center in the cylinder row direction when viewed from one side in the cylinder row direction.
Is arranged at a position higher than the lower end position P2.

The second branch passages 15 to 18 are connected to the outer peripheral portion of the surge tank 10 and have a second upstream end opening 15a to.
It slightly extends in a direction obliquely upward from 18a in a direction away from the engine unit 2, and joins in the middle of the straight line portion of the second pipe portions 11c to 14c of the first branch passages 11 to 14.

The first branch passages 11 to 14 are arranged so as to surround most of the outer circumference of the surge tank 10 (about 4/5), and the anti-engine unit 2 is provided in the second branch passages 15 to 18.
On the side, the second pipe parts 11c to 14c are connected to the surge tank 1
It is continuous linearly from the bottom of 0 to the top.

From the surge tank 10 to each of the four cylinders 3A ...
In order to make the passage length to the 3D intake port 8 equal,
First branch passage 1 corresponding to the two central cylinders 3B, 3C
Reference numerals 2 and 13 are first cylinders corresponding to the cylinders 3A and 3D at the left and right ends.
The surge tank 10 is arranged so as to extend downward from the branch passages 11 and 14 and curve upward to surround most of the outer circumference of the surge tank 10.

The first upstream end openings 11a to 14a are formed near the top of the outer peripheral portion of the surge tank 10. Of these four first upstream end openings 11a to 14a, the two first cylinders 3A and 3B on the right side correspond to the two first cylinders 3A and 3B.
The upstream end openings 11a and 12a are the second cylinder 3B from the right.
Corresponding to the second upstream end opening 16a and the surge tank 10
The two first upstream end opening / closing portions 13a, 14a corresponding to the two left cylinders 3C, 3D, which are formed on substantially the same circumference in the outer peripheral portion, correspond to the second cylinder 3C from the left. The second upstream end opening 17a and the outer peripheral portion of the surge tank 10 are formed on substantially the same circumference.

FIG. 5 shows the I-I of the intake system of the engine of FIG.
A cross-sectional view is shown showing the two first upstream end openings 11a on the right side,
The center line of 12a branches from one point on the outer circumference of the surge tank 10 and extends to form two first upstream end openings 11a, 12
a is formed so as to partially overlap in the substantially same circumferential direction. The two first upstream end openings 13a and 14a on the left side are formed similarly to the right side. That is, the four first upstream end openings 11a to 14a are formed close to each other in the vicinity of the central portion in the left-right direction of the surge tank 10, and from the throttle valve 24a to the four first upstream end openings 11a to 14a. The passage lengths are almost equal.

The second upstream end openings 15a to 18a of the second branch passages 15 to 18 are arranged side by side in the cylinder row direction with respect to the outer peripheral portion of the surge tank 10.

The four second upstream end openings 15a to 18a are arranged close to each other in the left-right direction so that the difference in passage length from the throttle valve 24a to the four second upstream end openings 15a to 18a becomes small. As described above, the length of the surge tank 10 in the left-right direction is shorter than the distance between the two intake ports 8 corresponding to the cylinders 3 at the left and right ends, respectively. 15
The difference in passage length from a to 18a is also small.

In the above structure, the first branch passages 11 to 1
4 is set to an intake pipe length that is tuned to the intake characteristic in the low and middle rotation range of the engine, and the first branch passage shorted by the second branch passages 15 to 18 is tuned to the intake inertia characteristic in the maximum rotation range of the engine. It is set to the intake length.

FIG. 10 is a development view of the rotary valve,
A cylinder in the intake port 8 in which the length L2 between the both ends 15a and 18a in the cylinder row direction of the second upstream end openings 15a to 18a is open to one side of the engine unit 2 and arranged side by side in the cylinder row direction. Length L3 between both ends in the row direction
It is set shorter.

Further, both end portions 11a, 14a and 12a of the first upstream end opening portions 11a to 14a in the cylinder row direction,
The length L1 between 13a is the second upstream end opening 15a-18.
It is set to be shorter than the length L2 between both ends 15a and 18a in the cylinder row direction of a.

The first upstream end openings 11a, 12a and 13a, 14 formed by partially overlapping each other.
“A” is arranged on substantially the same circumference with respect to the second upstream end openings 16a, 17a located in the middle in the cylinder row direction. <Variable intake mechanism> As shown in FIG.
The first upstream end openings 11a to 14a and the second upstream end openings 15a to 18a are respectively connected to the outer peripheral portion of the surge tank 10 so as to communicate with the internal space 22 of the surge tank 10, and four openings 10a and 10b, respectively. Are formed. In addition, inside the surge tank 10, the first upstream end openings 11a to 14a and the second upstream end openings 15a to 18a that overlap each other are provided.
Surge tank 1 to selectively open and close either
A rotary valve 20 is mounted which is rotatable around its axis 10c along the inner peripheral portion of 0.

FIG. 6 is a perspective view of the rotary valve. The rotary valve 20 made of synthetic resin has a hollow cylindrical outer wall 20a extending in the left-right direction over the entire length and an end wall 20b closing the left end of the surge tank 10. And are integrally formed. The rotation of the rotary valve 20 causes the four openings 20d formed in the outer wall 20a in the direction of the axis 10c and the openings 10a and 10b formed in the outer peripheral portion of the surge tank 10 to communicate with each other. The end openings 11a to 14a and the second upstream end opening 15a to
Either 18a is selectively opened and closed.

The four openings 20d are formed by overlapping each other with the first upstream end openings 11a, 12a.
And the first upstream end opening 12a (13a) and the second upstream end opening, which are formed to have a width in the cylinder column direction and a length in the radial direction larger than the opening areas of 13a and 14a and are formed on substantially the same circumference. The first upstream end opening 11a is formed to have a radial length larger than the separation distance from the 16a (17a), and when the engine speed to be described later is between a low speed side operating state and a high speed side operating state. 14a and the second upstream end opening 15
Both a-18a form a partially open transient.

A pivot shaft portion 20c is provided at the center of the end wall portion 20b.
Is provided so that the pivot shaft portion 20c is rotatably supported.

The structure of the rotary valve 20 is not limited to the structure of the above embodiment, and various structures can be adopted.

As shown in FIGS. 1 and 2, a diaphragm type actuator 21 for rotationally driving the rotary valve 20 is disposed on the left side of the surge tank 10, and an output portion of the actuator 21 is a pivot shaft portion 20c. Are linked to. The actuator 21 has a general structure in which the negative pressure of the intake system introduced from the intake pipe by the negative pressure introduction pipe is applied to the diaphragm to drive the output section.

As shown in FIG. 7, in an operating state where the engine speed is low, the opening 20d of the rotary valve 20 is located at the first upstream end openings 11a to 14a, and the internal space 22 of the surge tank 10 is located. And communicate with the second
The upstream end openings 15a-18a are closed.

On the other hand, as shown in FIG. 8, when the engine speed is in the high-speed operating state, the opening 20d of the rotary valve 20 is located at the second upstream end openings 15a to 18a, and the inside of the surge tank 10 is located. It communicates with the space 22 and closes the first upstream end openings 11a to 14a.

Further, as shown in FIG. 9, the opening portion 20d of the rotary valve 20 is located between the first upstream end opening portion 1 and the operating state where the engine speed is low speed side and high speed side.
1a to 14a and the second upstream end openings 15a to 18a, and are in a transitional state in which they are both open.

Next, the operation of the intake device 7 will be described.

When the engine 1 is operating on the low speed side (operating state on the low speed rotation side), as shown in FIG. 7, the rotary valve 20 is rotationally driven by the actuator 21 as necessary, and the inside of the surge tank 10 is driven. The space 22 and the first upstream end openings 11a to 14a communicate with each other, and the second upstream end openings 15a to 18a are kept closed by the rotary valve 20. At this time, the intake air enters the intake port 8 from the surge tank 10 through the first upstream end openings 11a to 14a, the first pipe parts 11b to 14b, the second pipe parts 11c to 14c, and the third pipe parts 11d to 14d. Since it is filled and the passage length from the surge tank 10 to the intake port 8 becomes long, the intake filling efficiency in the low speed side operating state is enhanced by the inertial effect.

Further, the second pipe portions 11c to 14 in which the second branch passages 15 to 18 merge with the first branch passages 11 to 14, respectively.
Since c is continuous in a straight line, the passage resistance at this confluence portion becomes small, and it is possible to prevent the intake charge efficiency from decreasing.

On the other hand, when the engine 1 is operating at a high speed (operating state on the high speed rotation side), as shown in FIG. 8, the rotary valve 20 is rotationally driven by the actuator 21 as necessary, and the surge tank 10 is rotated. Interior space 22
And the second upstream end openings 15a to 18a are communicated with each other, and the first upstream end openings 11a to 14a are held closed by the rotary valve 20. At this time, intake air is filled in the intake port 8 from the surge tank 10 through the second upstream end openings 15a to 18a and the second pipe portions 11c to 14c, and the passage length from the surge tank 10 to the intake port 8 is increased. Is shortened, the intake charging efficiency is increased in the high-speed side operating state due to the inertial effect.

Further, when the engine 1 switches from the low-speed side operating state to the high-speed side operating state, as shown in FIG. 9, the rotary valve 20 is rotationally driven by the actuator 21 as necessary, as shown in FIG. End opening 11a
˜14a and the second upstream end openings 15a to 18a are both partially opened. At this time, the first upstream end openings 11a to 14a and the second upstream end openings 15a to 18a.
The sum of the areas of the open parts of a is the first upstream end opening 11
By setting the opening areas of a to 14a to be equal to or larger than the opening areas of the second upstream end openings 15a to 18a, the intake outflow resistance is reduced and the intake charging efficiency is prevented from decreasing. Can be suppressed to

According to the engine intake device 7 of the first embodiment described above, the following effects can be obtained.

A) When switching from the low speed side operating state to the high speed side operating state, the rotary valve 20 is provided with the first upstream end openings 11a to 14a and the second upstream end openings 15a to 15a.
18a, which is a transitional state in which the intake air outflow area is equal to or larger than the intake air outflow area in the low speed side operating state and the high speed side operating state. As a result, the intake charging efficiency at the time of switching can be minimized.

B) First upstream end openings 11a, 14a and 1
Since 2a and 13a are radially overlapped on the outer circumference of the surge tank 10 and are formed close to the center in the left-right direction, they are arranged so as to surround most of the outer circumference of the surge tank 10. The intake device 7 can be made compact while ensuring the length of the first branch passages 11 to 14 required to obtain the inertial effect in the low speed operation state, which is also advantageous in terms of installation space.

C) The length of the surge tank 10 in the left-right direction is made shorter than the distance between the two intake ports 8 corresponding to the cylinders 3A, 3D at the left and right ends, respectively, and the four first upstream end openings 11a ... Of the 14a, the two first upstream end openings 11a, 12a on the right side and the two first upstream end openings 13a, 14a on the left side are formed so as to partially overlap each other in the outer peripheral portion of the surge tank 10, and The two first
Since the upstream end openings 11a and 12a and the two left first upstream end openings 13a and 14a are also close to each other, the throttle valve 24a to the first upstream end openings 11a to 14a.
To the first branch passage 11
-14 and the second branch passages 15-18 are unified in natural frequency, and the charging efficiency can be made uniform.

Further, the two first branch passages 12 and 13 corresponding to the two central cylinders 3B and 3C are provided at the two left and right ends.
The first branch passages 11 and 14 corresponding to the three cylinders 3A and 3D
Since it curves further downward than the above, the passage lengths from the surge tank 10 to the intake port 8 in the four first branch passages 11 to 14 are substantially equal in the low speed side operating state. Therefore, in the four first branch passages 11 to 14, the passage lengths from the throttle valve 24a to the intake port 8 become substantially equal, and the difference in the frequency of pressure pulsation due to the difference in the passage lengths also becomes small. The unpleasant sound caused by the noise can be minimized in the low-speed operation state in which the noise of the engine 1 is small and the unpleasant sound has a large influence on the outside.

Further, the four second upstream end openings 15a-1
Since 8a is also formed close to the outer peripheral portion of the surge tank 10, the difference in passage length from the throttle valve 24a to the intake port 8 in the second branch passages 15 to 18 is small even in the high speed side operating state. Therefore, it is possible to suppress the unpleasant noise even in the high-speed operation state. In addition, since the volume of the surge tank 10 can be reduced, the response can be improved.

D) Since the rotary valve 20 is rotatably mounted on the surge tank 10, a space for disposing the rotary valve 20 is almost unnecessary,
The intake device 7 can be made compact.

E) Since the second branch passages 15a to 18a are continuously joined linearly with the second pipe portions 11c to 14c of the first branch passages 11a to 14a, in the low speed side operating state. The passage resistance in the merging portion can be reduced, and the intake charging efficiency can be prevented from decreasing.
Further, since the third pipe portions 11d to 14d are also smoothly curved, it is possible to prevent the passage resistance from decreasing even in the high-speed side operating state, and to prevent the intake charging efficiency from decreasing.

F) The lower end positions P1 of the first branch passages 11 and 14 corresponding to the cylinders 3A and 3D at both ends in the cylinder row direction, when viewed from one side in the cylinder row direction, are the cylinders 3B and 3C at the center in the cylinder row direction.
By arranging the second branch passages 12 and 13 at a position higher than the lower end position P2 of the second branch passages 13 and 13, the passage lengths from the surge tank 10 to the respective cylinders are made substantially equal to each other, and the inertia effect is obtained in the low speed side operating region. Therefore, the torque can be improved. Further, since step spaces are formed at both ends in the cylinder row direction below the first branch passages 11 and 14, auxiliary machinery can be arranged in these spaces. [Second Embodiment] Next, an intake device for an engine according to a second embodiment of the present invention will be described.

The same elements as those in the first embodiment are designated by the same reference numerals and their description will be omitted. However, in the second embodiment,
A configuration in which the second branch passages 15 to 18 and the rotary valve 20 of the first embodiment are omitted can also be applied.

FIG. 11 is a front view of the engine air intake system of the second embodiment according to the present invention, FIG. 12 is a plan view of the engine air intake system of the second embodiment of the present invention, and FIG. 13 is related to the present invention. The right side view of the intake device of the engine of the second embodiment,
FIG. 14 is a sectional view taken along the line II-II of FIG. 13, and FIG. 15 is a view of the engine air intake device of the second embodiment according to the present invention seen from the engine unit side, respectively, and an engine air intake device 27 of the second embodiment is shown. The first branch passages 31 to 34 are provided so as to surround the surge tank 10 as in the first embodiment, and the first branch passages 31 to 34 are connected to the outer peripheral portion of the surge tank 10 at the first upstream end. Openings 31a to 34a
And the first pipe portions 31b to 34b that extend obliquely upward from the first upstream end openings 31a to 34a toward the engine unit 2 side and are curved and linearly extend downward of the surge tank 10.
And second pipe portions 31c to 34c linearly extending above the surge tank 10 while curving toward the engine unit 2 side below the surge tank 10, and curving toward the engine unit 2 side above the surge tank 10. Extension engine 1
The third pipe portions 31d to 34d are connected to the intake port 8 opening on the side surface of the casing via the mounting flange 25.

As in the first embodiment, the second branch passages 15 to 18 are provided, and the second upstream end openings 15a to 18a connected to the outer peripheral portion of the surge tank 10 are away from the engine unit 2. To the second pipe portion 31c of the first branch passages 31 to 34 while curving obliquely upward to
It joins in the middle of the straight part of ~ 34c.

Second pipe portions 31c to 34c extending upward from below the surge tank 10 in the first branch passages 31 to 34.
Are arranged in a substantially planar shape in the cylinder row direction on the side opposite to the engine unit 2 and are located at both ends of the cylinder row in the cylinder row direction.
The lower end positions P1 of the c and 34c are the second pipe portions 32c and 33c located at the center in the cylinder row direction when viewed from one side in the cylinder row direction.
Is arranged at a position higher than the lower end position P2.

Further, the first pipe portions 31b to 34b, which are curved from above the surge tank 10 and extend downward in the first branch passages 31 to 34, are formed so as to be arranged substantially in the cylinder row direction on the engine unit 2 side. Has been done.

Of the first branch passages 31 to 34, the branch passages 31 and 34 located at both ends in the cylinder row direction have the first pipe portions 31b and 34b after branching from the surge tank 10 located at the center in the cylinder row direction. The first branch passages 32 and 33 are curved at a position higher than the first pipe portions 32b and 33b, and spread to both sides of the first branch passages 32 and 33 located in the center in the cylinder column direction and extend below the surge tank 10. .

Further, the first branch passages 31 and 34 corresponding to the cylinders 3A and 3D at both ends in the cylinder row direction overlap each other in the cylinder row direction and branch upward from the surge tank 10 to form the first branch passage.
Extending to the cylinders 3A and 3D via the common branch passage 30A,
The first branch passages 32 and 33 corresponding to the cylinders 3B and 3C at the center in the cylinder row direction overlap each other in the cylinder row direction and branch downward from the surge tank 10 to form the second common branch passage 30B.
To the cylinders 3B and 3C.

At the outer peripheral portion of the surge tank 10, there is a first common opening 30a which opens toward the first upstream end openings 31a and 34a corresponding to the cylinders 3A and 3D at both ends in the cylinder row direction.
And a second common opening 30b opening toward the first upstream end openings 32a, 33a corresponding to the cylinders 3B, 3C at the center of the cylinder row direction are formed, and the first and second common branch passages 3 are formed.
Intake air is introduced into each of the first branch passages 11 to 14 via 0A and 30B.

The first upstream end openings 31a to 34a are formed near the top of the outer peripheral portion of the surge tank 10. Of these four first upstream end openings 31a to 34a, the first upstream end openings 31a and 34a corresponding to the cylinders 3A and 3D at both ends in the cylinder row direction are close to each other in the cylinder row direction and are located in the center of the cylinder row direction. Cylinder 3 which is located in the center of the cylinder row
The first upstream end openings 32a and 33a corresponding to B and 3C are located closer to the surge tank 1 than the first upstream end openings 31a and 34a.
No. 1 that extends below 0 and is located at the center in the cylinder row direction
The upstream end openings 32a and 33a and the outer peripheral portion of the surge tank 10 overlap each other on substantially the same circumference, and the common branch passage 3
Forming 0. That is, the four first upstream end openings 3
1a to 34a are formed close to each other in the vicinity of the center of the surge tank 10 in the left-right direction, and the passage lengths from the throttle valve 24a to the four first upstream end openings 31a to 34a are substantially equal.

As shown in FIGS. 14 and 15, at least the first upstream end openings 31a and 34a of the first branch passages 31 and 34 corresponding to the cylinders 3A and 3D at both ends in the cylinder row direction and the cylinder at the center in the cylinder row direction. The first upstream end openings 32a, 33a of the first branch passages 32, 33 corresponding to 3B, 3C are inclined in the intake flow direction S1 of the surge tank 10 and surround the surge tank 10 in a spiral shape. Further, the flow passage cross-sectional shape of the first branch passages 31 to 34 is formed into a substantially parallelogram inclined in the intake flow direction of the surge tank 10.

Other than that, the configuration of the rotary valve and the like is the same.

According to the engine intake device 27 of the second embodiment described above, the following effects can be obtained in addition to the effects of the first embodiment.

A) The lower end position P1 of the first branch passages 31 and 34 corresponding to the cylinders 3A and 3D at both ends in the cylinder row direction, when viewed from one side in the cylinder row direction, is the cylinders 3B and 3C at the center in the cylinder row direction.
By arranging the second branch passages 32 and 33 at a position higher than the lower end position P2 of the second branch passages 33, the passage lengths from the surge tank 10 to the respective cylinders are made substantially equal to each other while the inertia effect is obtained in the low speed side operating region. Therefore, the torque can be improved. Further, as shown in FIG. 16 showing the front view of the engine 1, the engine can be downsized, and the first branch passages 31, 3
Since stepped spaces SP are formed at both ends of the lower four cylinders in the cylinder row direction, auxiliary equipment such as the starter motor 41 and the compressor 42 of the air conditioner can be arranged in this space SP.

Incidentally, in FIG. 16, the engine unit 2
Is a cylinder block 2a, a cylinder head 2b,
The head cover 2c and the oil pan 2d are provided, and the starter motor 41 meshes with the flywheel 43 to rotationally drive the crankshaft. An oil filter 44 is provided below the starter motor 41.

B) By forming the first branch passages 31 to 34 so as to be arranged in a substantially planar shape in the cylinder row direction on the engine unit 2 side and the non-engine unit 2 side, the size of the engine in the front-rear direction can be reduced, Further, as shown in FIG. 17 showing a right side view of the engine 1, a radiator unit 45 including a radiator and an electric fan arranged in the front of the engine room, and the engine unit 2 are arranged between the radiator unit 45 and the engine unit 2 in the front-rear direction of the vehicle body. A space for arrangement can be secured.

(C) At least the cylinders 3 at both ends in the cylinder row direction
First upstream end openings 31a and 34a of the first branch passages 31 and 34 corresponding to A and 3D, and a cylinder 3B at the center in the cylinder row direction,
Since the first upstream end openings 32a and 33a of the first branch passages 32 and 33 corresponding to 3C are inclined in the intake flow direction S1 of the surge tank 10, the first branch passages 31 from the surge tank 10 are separated from each other. It is possible to reduce the intake flow resistance to ~ 34.

(D) Since the flow passage cross-sectional shape of the first branch passages 31 to 34 is formed into a substantially parallelogram inclined in the intake air flow direction of the surge tank 10, the intake air is made to flow along the inner wall of the passage. , The secondary flow that becomes a spiral component due to the reflection of the intake air on the inner wall of the passage can be suppressed, the intake pressure loss can be reduced, and the average flow coefficient (Cf) can be increased. [Third Embodiment] Next, as an engine intake device according to a third embodiment of the present invention, the structure of the intake port 8 of the cylinder head 2b and the first part near the connecting portion with the intake port 8 will be described.
The structure of the branch passages 11 to 14 will be described.

The same elements as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. However, in the third embodiment,
It can be applied to a combination with the intake device of the first or second embodiment or a combination with other different intake device configurations, and the second branch passages 15 to 18 and the rotary valve 20 of the first embodiment can be applied. The omitted configuration can also be applied.

FIG. 18 is a sectional view in the lateral direction of the engine showing the intake system for an engine according to the third embodiment of the present invention, FIG. 19 is an external view of a shutter valve, and FIG. 20 is a second embodiment of the present invention. 21 is a plan view of the intake system of the engine of FIG. 21, FIG. 21 is a sectional view inside the passage when the shutter valve is opened, FIG. 22 is a sectional view inside the passage when the shutter valve is closed, and FIG.
XI-XXI sectional view, FIG. 24 shows IV-IV sectional view of FIG. 21, and FIG. 25 shows VV sectional view of FIG. 21, respectively, and the intake device 37 of the engine of the third embodiment has four cylinders 3A to.
The intake port 8 and the third pipe portions 11d to 1d of the first branch passages 11 to 14 connected to the intake port 8 obliquely upward from 3D.
4d extends to the upstream side. The upstream side of the first branch passages 11 to 14 (not shown) has the same structure as that of FIGS. 1 to 5.

Further, the passages 11 to 1 are provided in the first branch passages 11 to 14 (third pipe portions 11d to 14d) near the downstream end openings 11e to 14e connected to the intake port 8.
The shutter valve 51 that closes a part of the cross section of the flow passage of No. 4 to generate the tumble flow in the cylinder 3 has the first branch passages 11 to 14
Is rotatably supported by a shaft 52 that passes through the axis of and crosses the approximate center of the flow path cross section.

As shown in FIG. 19, the shutter valve 51 includes a lower half portion 51a which closes the flow passage cross section of the first branch passages 11 to 14 below the shaft 52 when fully closed, and a flow above the shaft 52 when fully closed. A lower half portion 51b is formed by cutting out a portion above the shaft 52 so as not to block the road cross section (bent in the downstream direction around the middle of the flow path cross section).

The first branch passages 11 to 14 on the upstream side of the shutter valve 51 and the portion P of the intake port 8 on the downstream side which is not closed by the shutter valve 51.
The inner wall of No. 3 is formed in a substantially linear shape as compared with the conventional structure (dotted line portion P3 ′ in FIG. 18), and the first branch passages 11 to 14 on the upstream side and the intake port 8 on the downstream side sandwich the shutter valve 51. The part closed by the shutter valve 51 (see FIG.
8 is formed so as to bulge in the radial direction at the position where the shutter valve 51 is arranged, and the flow passage cross-sectional area of the first branch passages 11 to 14 at the position where the shutter valve 51 is arranged is defined by the shutter. It is formed to have a larger cross-sectional area of the flow path upstream and downstream of the valve 51.

Also, when viewed from one side of the engine in the cylinder row direction (the front and back direction of the paper surface in FIG. 18), the inclination angle θ2 of the first branch passages 11 to 14 is an upwardly inclined angle θ2.
Is larger than the inclination angle θ1 of.

The inner wall of the upper portion of the intake port 8 in which the valve guide 5a is disposed has a conventional structure in a section from upstream to downstream of the valve guide 5a (dotted line portion P in FIG. 18).
5 '), it is formed flat, and this flat portion P
5 is formed so as to reduce the flow passage area in the upper portion of the intake port 8 where the valve guide 5a is provided.

Further, the flow passage cross section from the vicinity of the branch portion in each intake port 8a, which branches into two and communicates with each of the cylinders 3A to 3D, to the throat portion P6 where the flow passage area on the downstream side is narrowed is 2 The upper portion 8b, the side surface portion 8c, and the lower portion 8c on the side between the intake ports 8a that branch into two are formed in a flat and rectangular shape as compared with the conventional structure (dotted line portion 8a 'in FIG. 23). Anti-intake port 8 branching into
The side surface portion 8e is formed into a round shape on the intermediate side.

The cross-sectional shape of the intake port 8 in the section from the upstream to the downstream of the valve guide 5a is such that the inner wall of the upper portion is substantially linear and the inner wall of the lower portion is inflated, and the first branch passages 11 to 14 are formed. The present invention can be applied by appropriately combining with the constitution in the vicinity of the connecting portion, but it is preferable to combine both constitutions.

According to the engine intake system of the third embodiment described above, the following effects can be obtained.

A) As shown in FIG. 19, the shutter valve 51 is notched at a portion above the shaft 52 so as not to close the flow passage cross section above the first branch passages 11 to 14 when fully closed, and the shutter valve 51 is not shown. By forming the first branch passages 11 to 14 on the upstream side and the inner wall of the portion P3 of the intake port 8 on the downstream side which is not closed by the shutter valve 51 so as to be substantially linear with 51 therebetween, the intake flow resistance is reduced. When the shutter valve 51 is closed, the tumble flow can be strengthened by the intake flow along the inner wall above the passage, while the shutter valve 5
1, the inner walls of the first branch passages 11 to 14 on the upstream side and the portion of the intake port 8 on the downstream side that is closed by the shutter valve 51 are formed so as to bulge in the radial direction at the position where the shutter valve 51 is disposed. Since the flow passage cross-sectional areas of the first branch passages 11 to 14 at the arrangement position of the shutter valve 51 are formed larger than the flow passage cross-sectional areas of the upstream and downstream of the shutter valve 51, when the shutter valve 51 is opened. The tumble flow becomes weak and flow resistance can be reduced. With this configuration, an engine with low fuel consumption and high output can be obtained.

B) First branch passages 11 to 1 formed so as to surround the surge tank 10 in order to increase the passage length.
In 4, the tumble flow can be strengthened when the shutter valve 51 is closed while ensuring a high output when the shutter valve 51 is opened.

C) The inner wall of the upper portion of the intake port 8 in which the valve guide 5a is arranged is formed flat in the section from the upstream side to the downstream side of the valve guide 5a. Since it is formed so as to reduce the flow passage area of the upper portion of the intake port 8 provided, it is possible to suppress the attenuation of the flow due to the inner wall surface of the upper portion of the intake port 8.

D) Further, the cylinders 3A to 3A are branched into two cylinders.
The cross section of the flow passage from the vicinity of the branch portion of each intake port 8 communicating with D to the throat portion P6 at the downstream side where the flow passage area is narrowed has an upper portion 8b on the side between the two intake ports 8 branching. , Side portion 8c and lower portion 8d
Is formed into a flat and rectangular shape, and the side surface portion 8e is formed into a round shape on the side between the non-intake ports 8 that branch into the two, so that when the shutter valve 51 is opened, as shown in FIG. 25, while increasing the intake flow velocity along the upper portion 8b and the lower portion 8d of the flow passage section from the first branch passages 11 to 14 to each intake port 8 to secure high output, FIG.
As shown in FIG. 5, when the shutter valve 51 is closed, the intake flow velocity in the upper portion 8b of the flow passage section from the first branch passages 11 to 14 to each intake port 8 is increased to strengthen the tumble flow and enhance the intake charging efficiency. be able to.

[Brief description of drawings]

FIG. 1 is a front view of an intake device for an engine according to a first embodiment of the present invention.

FIG. 2 is a plan view of the intake device for the engine according to the first embodiment of the present invention.

FIG. 3 is a right side view of the intake device for the engine according to the first embodiment of the present invention.

FIG. 4 is a left side view of the intake device for the engine according to the first embodiment of the present invention.

5 is a cross-sectional view taken along the line I-I of FIG.

FIG. 6 is a perspective view of a rotary valve.

FIG. 7 is an enlarged view of a main part of FIG. 5 (low-speed side operating state).

FIG. 8 is an enlarged view of a main part of FIG. 5 (high-speed side operation state).

9 is an enlarged view of a main part (transient state) of FIG.

FIG. 10 is a development view of a rotary valve.

FIG. 11 is a front view of an intake device for an engine according to a second embodiment of the present invention.

FIG. 12 is a plan view of an intake device for an engine according to a second embodiment of the present invention.

FIG. 13 is a right side view of an intake device for an engine according to a second embodiment of the present invention.

14 is a sectional view taken along line II-II of FIG.

FIG. 15 is a view of an intake device for an engine according to a second embodiment of the present invention as viewed from the engine unit side.

FIG. 16 is a front view of an engine equipped with an intake system for an engine according to a second embodiment of the present invention.

FIG. 17 is a right side view of an engine equipped with an engine air intake system according to a second embodiment of the present invention.

FIG. 18 is a cross-sectional view in the lateral direction of the engine showing an intake device for an engine according to a third embodiment of the present invention.

FIG. 19 is an external view of a shutter valve.

FIG. 20 is a plan view of an intake device for an engine according to a second embodiment of the present invention.

FIG. 21 is a sectional view of the inside of the passage when the shutter valve is opened.

FIG. 22 is a sectional view of the inside of the passage when the shutter valve is closed.

23 is a sectional view taken along the line III-III in FIG.

FIG. 24 is a sectional view taken along the line IV-IV in FIG. 21.

25 is a cross-sectional view taken along line VV of FIG.

FIG. 26 is a vertical sectional view of a conventional intake device.

FIG. 27 is a diagram illustrating the operation of the conventional intake device.

[Explanation of symbols]

1 engine 2 engine units 2a cylinder block 2b cylinder head 2c head cover 2d oil pan 3A-3D cylinder 5 intake valve 6 exhaust valve 7,27,37 Intake device 8,8a intake port 9,9a Exhaust port 10 surge tank 10a, 10b, 30a, 30b openings 11-14, 31-34 First branch passage 11a-14a, 31a-34a 1st upstream end opening part 15-18 Second branch passage 15a to 18a Second upstream end opening 20 rotary valve 23 Intake pipe 24 Throttle body 24a throttle valve 30 common branch passages 41 Starter motor 42 Air conditioner compressor 43 flywheel 44 oil pan 45 radiator unit 51 shutter valve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02F 1/42 F02F 1/42 F K F02M 35/104 F02M 35/10 102Q 102H 102Y (72) Inventor flat Shimoyuki Shimochi, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Taka Takashi, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture F-term (Reference) 3G023 AA01 AB01 AD06 AF01 3G024 AA01 AA09 AA17 DA08 DA17 DA18

Claims (5)

[Claims] 1. An intake port which is provided in an engine unit and which communicates with a cylinder from an obliquely upper side, an intake passage which is connected to the intake port from an obliquely upper side, and which is provided in the vicinity of a downstream end opening of the intake passage, A shutter valve that closes a part of a cross section of the flow path of the intake passage, and an intake device of an engine that generates a tumble flow in a cylinder, wherein the shutter valve and the shutters in the upstream and downstream intake passages and intake ports The inner wall of the portion that is not closed by the valve is formed in a substantially linear shape, and the inner wall of the portion that is closed by the shutter valve in the shutter valve and its upstream and downstream intake passages and intake ports has a diameter at the installation position of the shutter valve. Direction, the flow passage cross-sectional area of the intake passage at the shutter valve installation position is An intake device for an engine, characterized in that it is made larger than the cross-sectional area of the flow passage upstream and downstream of the turn valve. 2. When viewed from one side in the cylinder row direction of the engine, an inclination angle of the intake passage to an obliquely upper side is larger than an inclination angle of the intake port, and a portion where the shutter valve is disposed. An inner wall of an upper portion of the flow passage cross section of the intake passage that is not closed by the shutter valve is formed in a substantially linear shape, and is closed by the shutter valve of the flow passage cross section of the intake passage in the installation position of the shutter valve. The inner wall of the lower portion is formed so as to bulge in the radial direction at the position where the shutter valve is arranged, and the portion corresponding to the inner wall of the upper portion of the flow passage cross section of the intake passage in the shutter valve that is not blocked by the shutter valve is cut. The intake device for an engine according to claim 1, wherein the intake device is lacking. 3. The intake port branches from a collecting passage upstream of the intake port so as to communicate with each cylinder of the engine,
The intake passage is formed to extend from the collecting passage, curve downward from the engine unit side to the collecting passage, and curve from the engine unit side of the collecting passage to the collecting passage above to surround the collecting passage. The intake system for an engine according to claim 2, wherein: 4. The intake air provided with a valve guide for guiding the intake valve, which is formed by cutting out a portion corresponding to an inner wall of an upper portion of the shutter valve, which is not blocked by the shutter valve, in a flow passage cross section of the intake passage. The inner wall of the upper part of the port is formed flat in the section from the upstream to the downstream of the valve guide, and the flat part narrows the flow passage area of the upper part of the intake port where the valve guide is provided. The intake system for an engine according to claim 1, wherein: 5. The flow from the upstream end opening of the intake port, which is branched into two and communicates with the inside of the cylinder, and which communicates with the intake passage in the intake port, to a portion where the flow passage area downstream thereof is narrowed. The road section has a flat and rectangular upper portion, a side surface portion, and a lower portion on the side between the intake ports that branch into the two, and the side portion on the side between the anti-intake ports that branch into the two. The intake device for an engine according to claim 1, wherein the intake device is formed in a round shape.