JPH10103066A - Engine intake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively improve combustion in an engine by improving the function of swirl control valves being fully closed of forming swirls and tumbles. SOLUTION: Swirl control valves(SCV) 15 are arranged in intake ports 4 having common parts 4c where two downstream port parts 4a and 4b branch off on the upstream side thereof. The SCV 15 is formed with an opening 150 partly notched in the circumference thereof, through which intake air is made to flow when the SCV 15 is fully closed. The SCV 15 is adapted to fully close at substantially right angles of 90 deg.±6 deg. at its valve face with respect to the axis of an upstream intake port part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake device for an engine provided with an intake flow control valve upstream of an intake port for generating a vortex in a combustion chamber.

[0002]

2. Description of the Related Art Conventionally, an engine in which an intake flow control valve (swirl control valve: SCV) is provided upstream of an intake port so that a vortex is generated in a combustion chamber when the intake flow control valve is closed. Various intake devices are known.

For example, Japanese Patent Application Laid-Open No. Hei 7-180559 discloses an arrangement in which an intake flow control valve is disposed upstream of an intake port having a common part whose downstream side is branched into two port parts, and an upper part of the intake flow control valve is provided on one side of the intake flow control valve. The valve is provided with an opening formed by partially cutting out the valve, and when the intake flow control valve is fully closed, a range of 20 to 30 degrees with respect to a cross section perpendicular to the intake passage center line (intake port axis). The swirl (horizontal vortex) and the tumble (vertical vortex) are generated in the combustion chamber by the intake air flowing downstream of the intake port through the opening when the intake flow control valve is fully closed. An intake device adapted to perform this operation is shown.

[0004] The swirl and tumble contribute to the improvement of the combustibility, and are particularly effective for improving the combustibility when performing lean burn by stratified combustion.

[0005]

Generally, the intake flow control valve of this type of intake device has a relatively large inclination angle (for example, about 20 °) with respect to a direction perpendicular to the intake port axis when the valve is fully closed. Even in the device disclosed in the above publication, the intake flow control valve is in the range of 20 to 30 ° with respect to a cross section perpendicular to the intake passage center line (intake port axis) when fully closed. It is inclined.

However, the inventor of the present invention has found that when the swirl and the tumble are generated by an intake flow control valve having an opening partly notched at the periphery, the swirl and the tumble are completely closed. The swirl and tumble generation effect tends to decrease as the inclination angle at the time increases.

The swirl and tumble in the fully closed state of the intake flow control valve are affected by the position and the opening area of the opening of the intake flow control valve. For example, even if the swirl and the tumble are strengthened simply by reducing the opening area, the intake air flow resistance is increased and the intake air amount cannot be sufficiently secured. The reduction margin is reduced. That is, in order to expand the lean burn region, it is necessary to secure a sufficient intake air amount so as to obtain a lean state even in a high load side region where a large amount of fuel is supplied, while the combustion in the lean burn state is required. In order to improve the performance, it is required to enhance the swirl and the tumble. However, conventionally, it has been difficult to strengthen the swirl and the tumble while preventing the intake air flow resistance from increasing.

The present invention has been made in view of the above circumstances, and has as its object to provide an intake system for an engine capable of enhancing a swirl and tumble generating function when the intake flow control valve is fully closed and effectively improving combustion performance. And

[0009]

The invention according to claim 1 is
On the upstream side of the intake port whose downstream end opens into the combustion chamber, an intake flow control valve is provided that generates vortex flow in the combustion chamber by controlling the intake flow. In the intake device of the engine, a cutout opening is provided so that the intake air flows through the opening when the intake flow control valve is fully closed, and the intake flow control valve is fully closed in a predetermined operation range. The angle of the valve face when the intake flow control valve is fully closed with respect to the axis of the intake port is 90 ° ± 6.
It is set to a substantially right angle state of °.

With this configuration, when the intake flow control valve is fully closed, swirl and tumble are generated in the combustion chamber by the intake air flowing through the opening to the downstream side. By being set to be substantially perpendicular to the axis of the upstream intake port when fully closed, the function of generating swirl and tumble is enhanced, and the combustibility is improved.

In the present invention, the intake port has a common portion branching from the upstream port portion to two downstream port portions, and a rotary shaft extending in a direction in which the two downstream port portions are arranged upstream of the common portion. An intake air flow control valve that is rotatable from the fully closed state to the fully open state is provided at the center, and if the intake air flow valve is configured as described above (claim 2), the intake air flow control valve has a simple structure, Swirl generation and the like are performed favorably.

The shape of the opening of the intake flow control valve is as follows.
It is preferable to provide an opening which is notched in a vertical direction across the rotation axis at one side of the intake flow control valve corresponding to one of the downstream ports (claim 3). A swirl and a tumble are generated.

Furthermore, if an upper opening is provided above the intake air flow control valve and cut in parallel with the rotation axis and is continuous with the opening on one port side, the swirl and the tumble are provided. This is more advantageous due to the generation of air flow and reduction of intake air flow resistance.

An opening may be provided above the intake flow control valve.

According to a fourth aspect of the present invention, there is provided an opening of the intake flow control valve, and an injector for injecting fuel from above into the intake port is disposed in the intake port downstream of the intake flow control valve. If you do (claim 6),
This is advantageous for promoting the vaporization and atomization of the injected fuel.

Further, the intake port is formed in a straight shape at least from a position where the intake flow control valve is disposed to a downstream end of the common portion (claim 7), for example, from a position upstream of the intake flow control valve to a position near the intake valve. If the intake port is formed in a straight shape and the downstream end of the common portion is located above the peripheral portion of the combustion chamber (claim 8), swirl generation and the like are performed favorably.

In order to control the intake flow control valve, the intake flow control valve may be closed in an operation range on the low load side (claim 9). Thus, the swirl and tumble are strengthened, and the combustibility is enhanced, which is advantageous for stratified combustion and the like.

The intake flow control valve may be closed when the engine is cold (Claim 10), and in this case, the combustibility at the time of cold is enhanced.

The invention according to an eleventh aspect is directed to an intake port having a common portion branching from an upstream port portion to two downstream port portions, wherein the downstream ends of the two downstream port portions are open to the combustion chamber. An intake flow control valve is provided on the upstream side of the intake port, and a notch opening is provided in a part of a peripheral portion of the intake flow control valve. When the intake flow control valve is fully closed, the opening is sucked. In the intake system of the engine, in which the intake air flow control valve is fully closed in a predetermined operation range, the intake air flow control valve is notched vertically in one port side with a rotating shaft interposed therebetween. An opening is provided, and the intake port is formed in a straight shape at least from the location of the intake flow control valve to the downstream end of the common portion in the intake port.

According to this configuration, when the intake flow control valve is fully closed, swirl generation and the like are favorably performed by the intake flow passing through the opening located on one port side of the intake flow control valve.

In this configuration, the intake port is formed in a straight shape from a position upstream of the intake flow control valve to a position near the intake valve, and the downstream end of the common portion is located above the peripheral portion of the combustion chamber. (Claim 12), swirl and tumble generation and the like are performed favorably.

[0022]

Embodiments of the present invention will be described with reference to the drawings. 1 and 2 show the overall structure of an intake device according to one embodiment of the present invention. In these figures, an engine main body composed of a cylinder block 1, a cylinder head 2 and the like is provided with a plurality of cylinders, each of which has a combustion chamber 3 formed between a piston (not shown) and a lower surface of the cylinder head. The downstream end of the intake port 4 and the upstream end of the exhaust port 5 are open to the combustion chamber 3.

The intake port 4 is connected to the upstream port 2
It has a common portion 4c that branches into two downstream port portions 4a, 4b. Each of the openings of the downstream port portions 4a and 4b is opened and closed by the intake valve 6, respectively. The exhaust port 5 also has two upstream port portions 5a and 5b that open to the combustion chamber.
Each of the openings is opened and closed by an exhaust valve 7. An ignition plug 8 is provided at the center of the combustion chamber 3.

The intake manifold 10 connected to the engine body has an intake passage 12 for each cylinder connected to a surge tank 11, and these intake passages 12 are bent on the upstream side.
The downstream side extends linearly obliquely downward. The intake manifold 10 is connected to the cylinder head 2 with the downstream side of each intake passage 12 communicating with the intake port 4.

A swirl control valve 1 serving as an intake flow control valve for generating a vortex in the combustion chamber 3 by controlling the intake flow is provided upstream of the intake port 4.
5 (hereinafter, referred to as SCV15). The SCV 15 is located near the downstream end of the intake passage 12 and is rotatable from a fully closed state to a fully open state around a rotation shaft 16 extending in the cylinder row direction (the direction in which the two downstream port portions 4a and 4b are arranged). It has become.

The rotating shaft 16 is rotatably supported by a support 17 provided at the downstream end of the intake manifold 10 in a state of extending across the intake passages 12. One end is connected to an actuator 20 via a link 18 and a rod 19. The support portion 17 is provided with a stopper 21 that contacts the link 18 when the SCV 15 is fully closed, and a stopper 22 that contacts the link 18 when the SCV 15 is fully opened.

The SCV 15 is provided with an opening 150 in which a part of the periphery is cut out. In the present embodiment, as shown in FIG. 2 and also in FIG. 4, an opening 150 which is notched in a vertical direction with the rotation axis interposed therebetween is provided on one side corresponding to one downstream port. The size of the opening 150 is preferably set in a range of 0.3 to 0.5 times the intake passage area of the SCV arrangement portion.

The shape of the opening of the SCV 15 is not limited to that shown in FIG. 4, and for example, as shown in FIG.
In addition to the SCV 15, a narrow upper clearance (upper opening) 151 b which is cut out parallel to the rotation axis and continuous with the opening 151 a on one port side may be provided above the SCV 15. Alternatively, as shown in FIG. 6, an opening 152 is provided over the SCV 15 over the entire lateral direction, or as shown in FIG.
One provided with 53 is also conceivable. In FIGS. 4 to 7, hatched portions are openings.

FIG. 3 shows the fully closed state of the SCV 15.
As shown in this figure, the angle of the valve face when the SCV 15 is fully closed is
An axis (a dashed line in FIG. 3) of a portion extending from the downstream of the intake passage 12 to the upstream of the intake port 4 is substantially perpendicular to the axis, more specifically, sin6 ° = 0.1 (10%) is a tolerance of the SCV 15 when assembled. Considering this, the angle α of the valve face when the SCV 15 is fully closed with respect to the axis is set in a range of 90 ° ± 6 °.
The positions of the stoppers 21 and 22 are set so that the SCV 15 can be opened and closed between the fully closed state and the fully opened state in which the valve surface of the SCV 15 is substantially in the same direction as the axis.

Then, S by the actuator 20
The opening / closing operation of the CV 15 is controlled by a control unit (not shown) according to the operation state, and the SCV 15 is fully closed in a predetermined operation range. For example, the SCV 15 is fully closed in the low-load operation range. Alternatively, when the engine is cold, the SCV
15 is fully closed.

The intake passage 12 and the intake port 4
Is at least from the location of the SCV 15 to the common portion 4c.
Is formed straight up to a downstream end 4d (a position where the both downstream port portions 4a and 4b are completely separated). In the embodiment shown in the drawing, in particular, the intake port extends from a position upstream of the SCV 15 to a position near the intake valve 6. 4 is formed in a straight shape, and the downstream end 4 of the common portion 4c is formed.
d is located above the peripheral edge of the combustion chamber 3.

Above the downstream end of the intake passage 12,
An injector 23 for injecting fuel is provided. This injector 23 has an SCV1
Fuel is injected toward an intake valve 6 downstream of the intake port 4 from above.

According to the intake system of the present embodiment as described above, when the SCV 15 is fully closed in the low-load operation range, the intake air flowing downstream through the opening 150 of the SCV 15 causes the combustion chamber A swirl and a tumble are generated in 3. In this case, since the angle of the valve face when the SCV 15 is fully closed is substantially perpendicular to the axis R, the function of generating swirl and tumble is enhanced, and the combustibility is improved. In particular, the shape of the opening 150 as shown in FIG. 4 or the opening 15 as shown in FIG.
According to the shapes of 1a and 151b, swirl and tumble are more advantageously generated.

These operations will be specifically described with reference to FIGS. The swirl ratios shown in FIGS. 11 to 14 and 16 and the tumble ratios shown in FIGS. 13 and 15 all mean a swirl ratio and a tumble ratio by an impulse meter. In the following description, the set angle of the SCV 15 when the SCV 15 is fully closed means a tilt angle of the SCV 15 from this state, assuming that a state perpendicular to the axis of the intake port upstream portion is 0 °.

FIG. 8 shows an SC having an opening 150 on one side.
In an intake device in which V15 (see FIG. 4) is provided upstream of the intake port 4 as shown in FIGS. 1 and 2, the intake flow rate passing through half the area of the intake port 4 on the side where the opening 150 is located. At various positions downstream of the SCV 15 (S
(Distance from CV15). Data A1 in the figure is for the case where the opening area ratio of the SCV 15 to the intake port cross-sectional area is 31.5% and the set angle is 0 °. Data A2 is for the case where the opening area ratio is 50% and the set angle. Is set to 0 °, data B1 is obtained when the opening area ratio is set to 31.5% and the set angle is set to 20 °, and data B2 is set when the opening area ratio is set to 50% and the set angle is set. Is set to 20 °.

As shown in this figure, when the set angle is 20 °, the intake air flow passing through the half area is relatively small.
In particular, the flow rate decreases toward the downstream side. In comparison,
When the set angle is 0 °, the intake flow rate passing through the half area increases. This data shows that when the set angle is 20 °, the flow of intake air is easily dispersed to the other half of the intake port, whereas when the set angle is 0 °, the opening 150
Indicates that a large amount of intake air flows to one half of the intake port where the air intake port is located. In this manner, when the set angle is set to 0 °, an intake air flow biased toward one half of the intake port is obtained, so that the swirl generating action is enhanced. . If the common portion 4c is set at a position where the intake flow rate becomes maximum, the swirl generating action is enhanced.

FIG. 9 shows simulation data obtained by examining the flow of intake air in the intake port 4 when the set angle of the SCV 15 is set to 0 °. FIG.
Are the same simulation data when the set angle of is set to 20 °. In these figures, (a) shows the distribution of the intake flow in the horizontal plane at a height of 7 mm above the center of the intake port, and (b) shows the intake flow in the horizontal plane at the height of the center of the intake port. (C) shows the distribution of the intake air flow in the horizontal plane at a height of 7 mm below the center of the intake port. In these figures, the intake flow is represented by a vector (arrow), and the longer and denser the arrow, the stronger the intake flow.

FIG. 1 with the setting angle of the SCV 15 set to 20 °
According to the data of 0, the intake air is the opening 150 of the SCV15.
As a result, the flow toward the downstream side (the right side in the drawing) and the flow toward the lower side of the intake port and toward the shielding side (the lower side in the drawing) having no opening 150 also occur, and the intake flow Data B in FIG. 8
1 and B2 are also shown in the data of FIG. This tendency occurs because when the SCV 15 is tilted when fully closed, the airflow having a component in an oblique direction along the SCV 15 easily passes around the side without the opening 150 after passing through the opening 150. It is.

On the other hand, the set angle of the SCV 15 is 0 °.
According to the data shown in FIG. 9, (a), (b), and (c)
At each height position shown in FIG. 8, the state in which the airflow passing through the opening 150 of the SCV 15 is biased to one side of the intake port 4 is maintained for a relatively long distance, and the data A1 and A2 in FIG. This tendency is also shown in FIG. That is, if the set angle of the SCV 15 is set to 0 °, the oblique component of the airflow decreases, and the airflow that has passed through the opening 150 tends to go straight downstream.

The set angle of the SCV 15 is set to 0 °, and the intake port 4 is moved to a position near the intake valve 6 (at least to the downstream end 4d of the common portion 4c).
SCV1 by forming straight up to
5, the intake air passing through the opening 150 is linearly distributed to one side in a state of being unevenly distributed to one side, and mainly flows to one downstream port portion 4a.
Flows into the combustion chamber 3 and the swirl is favorably generated.

FIGS. 11A, 11B and 11C show the relationship between the cross-sectional area of the passage in the port (the opening area of the SCV 15) and the swirl ratio, the relation between the cross-sectional area of the passage in the port and the average flow coefficient, and the swirl ratio. And C1 and D1 and E1 are SCV in these figures.
When the set angle of No. 15 is 0 °, C2, D2 and E2 are SC
When the set angle of V15 is 10 °, C3, D3, and E3 indicate the cases where the set angle of SCV15 is 20 °. The larger the average flow coefficient is, the smaller the intake air flow resistance is.

As shown in FIG. 11A, the swirl ratio depends on the cross-sectional area of the passage in the port, and varies depending on the set angle of the SCV 15. When the set angle is 0 °, the swirl ratio becomes the largest. On the other hand, as shown in FIG.
The average flow coefficient depends on the cross-sectional area of the passage in the port,
It does not change depending on the set angle of SCV15. Therefore,
As shown in FIG. 11C, when the set angle of the SCV 15 is set to 0 °, the swirl ratio becomes larger even with the same average flow coefficient as compared with the case where the SCV 15 is inclined.

FIGS. 12 (a) and 12 (b) show the swirl ratio and the average flow coefficient with the set angle of the SCV 15 on the horizontal axis using the cross-sectional area of the passage in the port as a parameter. When the cross-sectional area is 265 mm ² , F2 and G2 indicate the case where the cross-sectional area of the passage in the port is 300 mm ² , and F3 and G3 indicate the case where the cross-sectional area of the passage in the port is 395 mm ² . To 0
It is understood that the swirl ratio can be increased without decreasing the average flow coefficient by setting the angle to °.

Next, the relationship between the shape of the opening of the SCV 15 and the swirl ratio and the tumble ratio will be described with reference to FIGS.

FIG. 13 shows the swirl ratio (S1) and the tumble ratio (T1) when the SCV 15 is taken as the lateral opening 150 as shown in FIG. Tumble ratio when opening 152 (T2)
7 shows a swirl ratio (S3) and a tumble ratio (T3) when the upper opening 153 is as shown in FIG. 7, and an average flow coefficient (Cf). The upper opening 152
The swirl ratio in this case is not shown because it is extremely small. The average flow coefficient (Cf) is hardly affected by the shape of the opening of the SCV 15 and mainly depends on the opening area.

FIG. 14 shows the relationship between the average flow coefficient and the swirl ratio when the side opening 150 as shown in FIG.
1) and the upper opening 152 as shown in FIG.
2) and a case (H3) where the upper opening 153 is formed as shown in FIG. 7.

FIGS. 15A, 15B and 15C show the relationship between the distance δ from the center of the intake port to the center of the opening of the SCV 15 and the tumble ratio.
And the relationship between the ratio (A / δ) of the area A and the distance δ (A / δ) and the tumble ratio, respectively, and the relationship between T11 and T11 in the figure. , T
21 and T31 are data when the side opening 150 is used as shown in FIG. 4, and T12, T22 and T32 are data when the upper opening 152 is used as shown in FIG.

As shown in FIGS. 13 and 14, of the three of the side opening 150, the upper opening 152, and the upper opening 153, the side opening 150 can maximize the swirl ratio. This is because the airflow on one downstream port 4a side can be strengthened.

Furthermore, as shown in FIGS. 13 and 15, the tumble ratio can be increased by forming the side opening 150. This is because, when the side opening 150 is used, the distance from the center of the intake port is longer than in the case where the upper opening 152 is used. When the air flows into the upper opening 152, the intake air flow is diverted to the downstream ports 4a and 4b, so that the flow velocity tends to decrease. This is because the flow rate can be easily maintained.

FIG. 16 shows a side opening 151 as shown in FIG.
4A and the upper clearance 151b, the relationship between the width of the upper clearance 151b, the swirl ratio, and the average flow coefficient is shown. As shown in this figure, if the upper clearance 151b is relatively small, such as up to about 2 mm, the swirl ratio hardly decreases and the average flow coefficient increases. Therefore, the swirl can be strengthened while reducing the intake resistance.

According to the data shown in FIGS. 13 to 16, in order to enhance the swirl and tumble while avoiding an increase in the intake air flow resistance, the SCV 15 is provided with a side opening 150 as shown in FIG. It is preferable to provide the side opening 151a and the upper clearance 151b.

As shown in FIGS. 1 and 2, the SCV 15
In the case where an injector 23 for injecting fuel from the upper part is provided in the intake port 4 located downstream of the SCV, if the SCV 15 is provided with an upper clearance 151b as shown in FIG. 5 or an upper opening 152 as shown in FIG. It is possible to promote the vaporization and atomization of the injected fuel by the intake flow passing through the upper side of the port 4.

The control of the SCV 15 may be such that the SCV 15 is closed when the engine is cold. In this case, the combustion chamber is improved when the engine is cold by accelerating the vaporization and atomization of the fuel. Is done.

[0054]

According to the present invention, an intake flow control valve is provided with an opening having a part cut off at a peripheral portion so that the intake air flows through the opening when the intake flow control valve is fully closed.
Since the angle of the valve surface when the intake flow control valve is fully closed with respect to the axis of the upstream intake port is set to a substantially right angle of 90 ° ± 6 °, when the intake flow control valve is fully closed, the intake flow resistance is reduced. It is possible to effectively generate swirls and tumbles while avoiding an increase.

In particular, the intake port has a common portion that branches from an upstream port portion to two downstream port portions, and an intake flow control valve is provided upstream of the common portion, and one downstream port of the intake flow control valve is provided. If one side portion corresponding to the portion is provided with an opening notched in the vertical direction across the rotation axis, the swirl and tumble generation function can be enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an intake device according to an embodiment of the present invention.

FIG. 2 is a partially cutaway schematic plan view showing the intake device.

FIG. 3 is an enlarged sectional view of an intake flow control valve arrangement portion.

FIG. 4 is a diagram showing a first example of an opening of an intake flow control valve.

FIG. 5 is a diagram showing a second example of the opening of the intake flow control valve.

FIG. 6 is a view showing a third example of the opening of the intake flow control valve.

FIG. 7 is a view showing a fourth example of the opening of the intake flow control valve.

FIG. 8 is a diagram showing a flow rate of intake air flowing on one half side of an intake port at each part downstream of the intake flow control valve.

FIGS. 9A, 9B, and 9C show the flow of intake air at various height positions in the intake port, and show a case where the set angle of the intake flow control valve is set to 0 °. is there.

10 (a), (b) and (c) show the flow of intake air at various height positions in an intake port, and are diagrams showing a case where a set angle of an intake flow control valve is set to 20 °. FIG. is there.

11 (a) shows the relationship between the cross-sectional area of the passage in the port and the swirl ratio, FIG. 11 (b) shows the relation between the cross-sectional area of the passage in the port and the average flow coefficient, and FIG. 11 (c) shows the relation between the swirl ratio and the average flow coefficient FIG. 4 is a diagram showing a relationship between the set angle of the intake flow control valve as a parameter.

FIG. 12 (a) shows the relationship between the set angle of the intake flow control valve and the swirl ratio, and FIG. 12 (b) shows the relationship between the set angle and the average flow coefficient, using the port cross-sectional area as a parameter. FIG.

FIG. 13 is a diagram showing data obtained by examining the relationship between the opening area of the intake flow control valve and the swirl ratio, the tumble ratio, and the average flow coefficient by variously changing the shape of the opening of the intake flow control valve.

FIG. 14 is a diagram showing data obtained by examining the relationship between the swirl ratio and the average flow coefficient by variously changing the shape of the opening of the intake flow control valve.

FIG. 15 (a) shows the relationship between the distance from the port center to the opening and the swirl ratio, FIG. 15 (b) shows the relationship between the value obtained by multiplying the distance by the opening area and the swirl ratio, and FIG. ) Indicates the relationship between the ratio of the opening area and the distance and the swirl ratio,
It is a figure which shows the data examined by changing the shape of the opening part of an intake flow control valve variously, respectively.

FIG. 16 is a diagram showing the relationship between the upper clearance and the swirl ratio when an upper clearance is provided in the intake flow control valve.

[Explanation of symbols]

 Reference Signs List 3 Combustion chamber 4 Intake port 4a, 4b Downstream port part 4c Common part 6 Intake valve 10 Intake manifold 15 SCV 150, 151a, 151b, 152, 153 Opening 16 Rotating shaft 23 Injector

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02M 69/00 360 F02M 69/00 350P 350W (72) Inventor Masanori Nakamura 3-1, Fuchu-cho, Shinchu, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Mikiko Fujii 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Masakazu Matsumoto 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Invention Person Toshihide Yamamoto 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Osamu Aoki 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (12)

[Claims] 1. An intake flow control valve that generates a vortex in a combustion chamber by controlling intake flow is provided upstream of an intake port having a downstream end opening to a combustion chamber. The engine is provided with an opening in which a part of the intake flow control valve is provided so that the intake air flows through the opening when the intake flow control valve is fully closed, and the intake flow control valve is fully closed in a predetermined operation range. An intake device for an engine, wherein an angle of a valve surface of the intake flow control valve with respect to an axis of an upstream intake port portion when the intake flow control valve is fully closed is set to a substantially right angle of 90 ° ± 6 °. 2. The intake port has a common portion branching from an upstream port portion to two downstream port portions, and is arranged upstream of the common portion around a rotation shaft extending in a direction in which the two downstream port portions are arranged. 2. The intake system for an engine according to claim 1, further comprising an intake flow control valve rotatable from a fully closed state to a fully opened state. 3. The engine according to claim 2, wherein the intake flow control valve has an opening which is notched in a vertical direction with a rotation shaft interposed therebetween, at one side corresponding to the one downstream port. Intake device. 4. The engine according to claim 3, wherein an upper opening is provided above the intake flow control valve, the upper opening being cut out in parallel with the rotation axis and continuing to the opening on one port side. Intake device. 5. The intake system for an engine according to claim 1, wherein an opening is provided above the intake flow control valve. 6. An intake port downstream of an intake flow control valve,
6. An intake system for an engine according to claim 4, wherein an injector for injecting fuel from an upper portion into the intake port is arranged. 7. The intake device for an engine according to claim 3, wherein the intake port is formed in a straight shape at least from a position where the intake flow control valve is disposed to a downstream end of the common portion. 8. The intake port is formed in a straight shape from a position upstream of the intake flow control valve to a position near the intake valve, and is arranged such that a downstream end of the common portion is located above a peripheral portion of the combustion chamber. The intake device for an engine according to claim 7, wherein 9. The intake system for an engine according to claim 3, wherein the intake flow control valve is closed in an operation range on a low load side. 10. The intake flow control valve is closed when the engine is cold.
An intake device for an engine according to any one of the above. 11. An intake port having a common portion branching from an upstream port portion to two downstream port portions, wherein downstream ends of the both downstream port portions are open to a combustion chamber,
An intake flow control valve is provided on the upstream side of the intake port, and a cut-out opening is provided in a part of a peripheral portion of the intake flow control valve so that the intake air flows through the opening when the intake flow control valve is fully closed. In the intake device for an engine, wherein the intake flow control valve is fully closed in a predetermined operation range, an opening notched in a vertical direction across a rotation axis on one port side of the intake flow control valve. And a straight intake port extending at least from the location of the intake flow control valve to the downstream end of the common portion in the intake port. 12. The intake port is formed in a straight shape from a position upstream of the intake flow control valve to a position near the intake valve, and is arranged such that a downstream end of the common portion is located above a peripheral portion of the combustion chamber. The air intake system for an engine according to claim 11, wherein: