JPH09170526A - Intake device for internal combustion engine - Google Patents

Abstract

(57) Abstract: In an intake system for an internal combustion engine, fuel injected from an injector is prevented from adhering to a wall surface of an intake passage to form a wall flow. SOLUTION: An intake flow control valve 8 that throttles an intake passage according to operating conditions, and a guide groove 21 that is recessed in a groove shape with respect to an intake passage wall surface 20 and that allows intake air to pass when the intake flow control valve 8 is closed.
And an injector 3 that faces the guide groove 21 and injects fuel into the intake port 11.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an improvement of an intake system for an internal combustion engine.

[0002]

2. Description of the Related Art In an engine in which fuel injected from an injector into an intake passage is mixed with intake air and sucked into a combustion chamber, the fuel is injected from the injector in order to improve characteristics when the operating state changes transiently. It is required to prevent the fuel from adhering to the wall surface of the intake passage to form a wall flow.

FIG. 18 shows a conventional intake system for an internal combustion engine.
(See Japanese Utility Model Laid-Open No. 61-80365).

An auxiliary air passage 104 having one end opened near the fuel injection port of the injector 103 and the other end opened at the intake passage 101 upstream of the air flow control valve 102 is provided.

Due to the pressure difference generated before and after the air flow control valve 102, the auxiliary air, which is a part of the intake air, is guided to the fuel injected from the injector 103 through the auxiliary air passage 104, and the fuel sucked into the cylinder is discharged. It is designed to promote atomization.

Further, when the air flow control valve 102 is closed, the intake air flowing through the intake passage 101 is removed from the air flow control valve 1.
By being guided through the notch 02, the combustion chamber 1
The intake flow velocity is increased to generate an intake swirl flow in the combustion chamber.

[0007]

However, in such a conventional intake system for an internal combustion engine, the intake flow control valve 1 is operated when the intake flow control valve 102 is closed.
There is a problem that the fuel spray injected from the injector 103 is deflected by the high-speed air flow passing through the notch 02 and adheres to the upper part of the wall surface of the intake passage located in front of the injector 103 to easily become a wall flow. It was

When a wall flow of fuel occurs on the wall surface of the intake passage, the control responsiveness of the air-fuel ratio of the air-fuel mixture supplied to the combustion chamber deteriorates at the transition of changes in the fuel injection amount. Further, atomization of fuel may be hindered, which may lead to deterioration of emission and fuel efficiency.

Further, since the intake air is guided through both the cutout portion of the intake flow control valve 102 and the auxiliary air passage 104 during the operation in which the intake flow control valve 102 is closed, The intake air flow velocity passing through the notch is limited, and it is difficult to sufficiently increase the force of the swirl or tumble air flow generated in the combustion chamber.
As a result, the region where the air-fuel ratio of the air-fuel mixture can be made lean becomes narrow, which may lead to deterioration of fuel efficiency.

It is an object of the present invention to solve the above problems and prevent the fuel injected from the injector from adhering to the wall surface of the intake passage to form a wall flow in the intake system of the internal combustion engine.

[0011]

An intake system for an internal combustion engine according to claim 1, wherein an intake passage for guiding intake air into a combustion chamber, an intake flow control valve for narrowing the intake passage in accordance with operating conditions, and an intake passage wall surface. On the other hand, it is provided with a guide groove that is recessed in a groove shape and that allows intake air to pass when the intake flow control valve is closed, and an injector that faces the guide groove and injects fuel into the intake passage.

The intake system for an internal combustion engine according to claim 2 is
In the invention according to claim 1, a recess facing the injector is formed on the upstream side of the guide groove.

An intake system for an internal combustion engine according to claim 3 is
The invention according to claim 1 or 2, wherein two intake ports connected to the combustion chamber are formed by branching in a V shape.
Two guide grooves are formed in each intake port by branching in a V shape.

An intake system for an internal combustion engine according to claim 4 is
In the invention according to claim 3, the injector is faced with the guide groove branched into the V-shape, and the V-shaped guide groove is formed so as to sandwich the V-shape guide groove in each intake port.

An intake system for an internal combustion engine according to claim 5 is
In the invention according to claim 3, an injector is made to face the guide groove branched into the V-shape, and a cutout portion is formed in the intake flow control valve for allowing intake air to flow when the valve is closed. Formed offset to the side of the port.

An intake system for an internal combustion engine according to claim 6 is
The invention according to claim 1 or 2, wherein two intake ports connected to the combustion chamber are formed by branching in a V shape.
One guide groove is formed toward one intake port.

An intake system for an internal combustion engine according to claim 7 is
In the invention according to claim 6, a cutout portion is formed in the intake air flow control valve for passing intake air when the valve is closed, and the cutout portion is formed toward an intake port where the guide groove extends.

An intake system for an internal combustion engine according to claim 8 is
In the invention according to claim 6, a cutout portion that allows the intake air to pass therethrough is formed in the intake flow control valve, and the cutout portion is formed toward an intake port different from the intake port in which the guide groove extends.

An intake system for an internal combustion engine according to claim 9 is
In the invention according to claim 1 or 2, three intake ports connected to the combustion chamber are branched and formed, and one guide groove is linearly formed in the central intake port.

[0020]

In the intake system for an internal combustion engine according to claim 1, in an operating state in which the intake flow control valve is open, the intake flow control valve does not throttle the intake flow and mixes with the fuel spray injected from the injector. While being sucked into the combustion chamber, the air-fuel mixture is made uniform.

In the operating state in which the intake flow control valve is closed, most of the intake air is collected in the guide groove, and the flow velocity of the intake air flowing through the guide groove is increased, so that atomization of the fuel spray injected from the injector is promoted. As well as
The fuel spray is prevented from adhering to the wall surface of the intake passage to form a wall flow.

Since the wall flow of the fuel is prevented from being generated on the wall surface of the intake passage in this way, the control response of the air-fuel ratio is improved during the transition in which the fuel injection amount changes. Further, since atomization of the fuel is promoted, the emission can be improved and the fuel consumption can be reduced.

Under the operating condition in which the intake flow control valve is closed, the high-speed intake flow collected in the guide groove causes a swirl flow in the combustion chamber. The swirling flow generated in the combustion chamber promotes the mixing of the fuel spray and the air, whereby good combustibility is obtained, and the lean burn region where the air-fuel ratio is diluted can be expanded.

In the intake system for an internal combustion engine according to a second aspect of the invention, fuel injected from the injector is injected to the upstream side of the guide groove through the recess, and the intake flow control valve closes the guide groove in an operating state in which the valve is closed. By joining with the flowing high-speed intake air flow, atomization of the fuel spray is promoted and the fuel spray is prevented from adhering to the wall surface of the intake passage to form a wall flow.

In the intake system for an internal combustion engine according to the present invention, since the guide groove branched into a V shape is formed in each intake port branched into a V shape, the intake flow control valve is closed. When the portion passes through the guide groove, a swirling flow swirling in the vertical direction is generated in the combustion chamber.

The swirling flow generated in the combustion chamber promotes the mixing of the fuel spray and the air, whereby good combustibility is obtained, and the lean burn region where the air-fuel ratio is diluted can be expanded. .

In the intake system for the internal combustion engine according to the fourth aspect, most of the intake air passes through the respective guide grooves in the operating state in which the intake flow control valve is closed. The fuel injected from the injector is injected into the inner guide groove and joins with the high-speed intake air flowing through the guide groove,
The atomization of the fuel spray is promoted, and the fuel spray is prevented from adhering to the wall surface of the intake passage and forming a wall flow.

Under the operating condition in which the intake flow control valve is closed, the high-speed intake flow collected in the inner guide groove is guided to the central portion of the combustion chamber, and swirls in the longitudinal direction in the central portion of the combustion chamber. Occur.

On the other hand, the fuel-free high-speed air flow passing through the outer guide groove swirls vertically in the side portion of the combustion chamber under the operating condition in which the intake flow control valve is closed.

Since the rich air-fuel mixture swirls in the central portion of the combustion chamber as the piston descends in this manner, fuel is collected near the spark plug as the piston rises, and stratification of the air-fuel mixture occurs. Is done. As a result, good flammability can be obtained, and the lean burn region can be expanded.

In the intake system for an internal combustion engine according to claim 5, most of the intake air passes through the guide groove and the cutout portion in the operating state in which the intake flow control valve is closed. The fuel injected from the injector is injected into the guide groove,
By merging with the high-speed intake air flow flowing through the guide groove, atomization of the fuel spray is promoted and the fuel spray is prevented from adhering to the wall surface of the intake passage to form a wall flow.

Under the operating condition in which the intake flow control valve is closed, the high-speed intake flow containing the fuel collected in the guide groove is guided to the central portion of the combustion chamber, and swirls vertically in the central portion of the combustion chamber. Create a flow. On the other hand, the fuel-free high-speed air flow passing through the notch swirls in the side portion of the combustion chamber.

Since the rich air-fuel mixture swirls in the central portion of the combustion chamber as the piston descends in this manner, fuel is collected near the spark plug as the piston rises, and stratification of the air-fuel mixture occurs. Is done. As a result, good flammability can be obtained, and the lean burn region can be expanded.

In the intake system for the internal combustion engine according to the sixth aspect, since one guide groove is formed in one intake port branched into a V shape, most of the intake air is generated in the operating state in which the intake flow control valve is closed. By passing through the guide groove, a swirling flow having a swirling component in the lateral direction is generated in the combustion chamber.

The swirling flow generated in the combustion chamber promotes the mixing of the fuel spray and the air, whereby good combustibility is obtained, and the lean burn region can be expanded.

In the intake system for the internal combustion engine according to the seventh aspect, since the notch is formed in the intake flow control valve toward the intake port where the guide groove extends, the intake flow control valve is operated in a closed operating state. Most of the gas passes through the guide groove and the notch and flows into the combustion chamber from the same intake port, so that the force of the swirling flow having a swirling component in the lateral direction generated in the combustion chamber is strengthened.

Since the swirling flow generated in the combustion chamber promotes the mixing of the fuel spray and the air, good combustibility can be obtained, and the lean burn region can be expanded.

In the intake system for the internal combustion engine according to the eighth aspect, since the notch is formed in the intake flow control valve toward the intake port different from the intake port in which the guide groove extends,
When the intake flow control valve is closed, most of the intake air passes through the guide groove and the notch and flows into the combustion chamber from different intake ports, causing a vertical swirling flow in the combustion chamber. It

The high-speed intake flow containing the fuel collected in the guide groove is sucked into the combustion chamber through one of the intake ports through the guide groove, and causes a swirling flow that vertically swirls in the combustion chamber. A high-velocity intake flow containing no fuel that has passed through the notch is sucked into the combustion chamber from the other intake port, and causes a swirling flow that vertically swirls in the combustion chamber.

As the piston descends in this manner, the rich air-fuel mixture swirls in the side portion of the combustion chamber. Therefore, by exposing the spark plug to the side portion of the combustion chamber, the piston rises. Along with this, the fuel is collected in the vicinity of the spark plug, and the mixture is stratified. As a result, good flammability can be obtained, and the lean burn region can be expanded.

In the intake system for an internal combustion engine according to a ninth aspect, the intake flow control valve has a structure in which three intake ports are formed by branching and one guide groove is linearly formed in the central intake port. Under the operating condition in which the valve is closed, the high-speed intake flow containing the fuel collected in the guide groove is linearly guided to the central portion of the combustion chamber. As a result, as the piston descends, the rich mixture swirls in the center of the combustion chamber, and as the piston rises, fuel is collected near the spark plug, and stratification of the mixture is performed. It is possible to expand the lean burn area.

[0042]

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

As shown in FIG. 2, the combustion chamber wall 18 of the cylinder head 10 is formed to be inclined in a pent roof shape.

As shown in FIG. 1, two intake ports 11 and two exhaust ports 19 are opened in the combustion chamber wall 18 so as to face each other with the spark plug interposed therebetween.

A boss portion 17 to which one spark plug is attached is formed in the cylinder head 10 so as to be surrounded by the openings of the two intake / exhaust ports 11 and 19.

In the cylinder head 10, a water jacket 25 is formed around the intake / exhaust ports 11, 19 and the spark plug boss 17. Water jacket 25
The heat of the combustion chamber wall 18 and the like is carried away by the cooling water that circulates.

A valve seat (not shown) is fitted in the opening of the intake port 11 with respect to the combustion chamber 1, and the intake port 11 is opened and closed in synchronization with the engine rotation by an intake valve seated on the valve seat.

As the intake valve is opened, the engine inhales intake air (mixture) from the intake port 11 into the combustion chamber 1, compresses this intake air with a piston, ignites and burns with an ignition plug, and exhausts the exhaust valve. Exhaust as each port is opened 1
9, and each of these steps is continuously repeated.

A throttle valve (not shown) is provided in the intake passage upstream of the intake port 11. The throttle valve opens and closes in conjunction with the accelerator pedal to adjust the intake air amount.

The injector 3 facing the intake port 11 is attached to the cylinder head 10. Fuel is injected from the injector 3 to the intake port 11.

The injector 3 is driven to open by a drive pulse signal output from a control device (not shown) in synchronization with engine rotation, and injects fuel adjusted to a predetermined pressure.

The cylinder head 10 has a partition wall 26 that partitions the two intake ports 11.

As shown in the BB cross section of FIG. 3, the intake flow control valve 8 is provided upstream of the partition wall 26 of the intake port 11.
Is interposed. The butterfly type intake flow control valve 8 is
It includes a valve body 15 and a valve shaft 16 that rotatably supports the valve body 15. The valve body 15 is formed in an elliptic plate shape similar to the cross-sectional shape of the intake port 11.

The intake flow control valve 8 has an actuator (not shown) connected to one end of a valve shaft 16 and is substantially orthogonal to the passage center line of the intake passage 2 from a fully opened position substantially parallel to the passage center line of the intake passage 2. It is driven to rotate over the fully closed position. A control device (not shown) controls the intake flow control valve 8 to be closed in a predetermined low speed and low load region according to the contents of a map preset according to the operating state of the engine.

Two guide grooves 21 are formed below the intake flow control valve 8 in the intake passage wall surface 20 of the cylinder head 10 along the intake flow direction. When the intake flow control valve 8 is closed, most of the intake air is linearly guided to the combustion chamber 1 through the guide grooves 21, so that an intake swirl flow is generated in the combustion chamber 1.

Each guide groove 21 extends linearly from the upstream side of the intake flow control valve 8 to the valve seat. Each guide groove 21 extends in a V shape so as to sandwich the partition wall 26.

Each guide groove 21 extends along the combustion chamber wall 18 and the valve face of the exhaust valve which are inclined in a pent roof type.

Each guide groove 21 is formed such that its center extension line is located closer to the center of the cylinder than the center line of each intake valve. Therefore, the intake air is guided linearly to the combustion chamber wall 18 through the respective guide grooves 21, so that an intake swirl flow (tumble) that swirls in the vertical direction in the central portion of the combustion chamber 1.
Occur.

As shown in the C-C sectional view of FIG. 3, each guide groove 21 has a substantially rectangular cross section. Each guide groove 2
1 is defined by a pair of side wall portions 31 extending in the vertical direction and a bottom wall surface 32 connecting the side wall portions 31.

A recess 22 facing the injector 3 is formed in the middle of the guide groove 21. The concave portion 22 is arranged at a bent portion where the inclination angle of the guide groove 21 changes. The recess 22 becomes gradually deeper from the middle of the guide groove 21 to the upstream side. The recess 22 defines a space through which the fuel spray injected from the injector 3 passes.

In the injector 3, the two fuel injection ports 33 are opened facing the recess 22. Center line O ₃ of each fuel injection port 33
₃ is arranged on each guide groove 21. The fuel spray injected from each fuel injection port 33 is adapted to diffuse along each guide groove 21 as shown by a two-dot chain line in FIG.

The configuration is as described above. Next, the operation will be described.

In the operating state in which the intake flow control valve 8 is opened, the intake flow control valve 8 does not throttle the flow of intake air, and is mixed with the fuel spray injected from the injector 3 and is sucked into the combustion chamber 1. , The air-fuel mixture is made uniform.

When the intake flow control valve 8 is closed in a predetermined low speed and low load region, most of the intake air is collected in the guide groove 21, and the flow velocity of the intake air flowing in the guide groove 21 is, for example, 60 m / s.
And is raised. As shown in FIG. 4, the intake flow velocity is set to the guide groove 2
Increased along 1.

The fuel injected from the injector 3 is injected to the upstream side of the guide groove 21 via the recess 22 and joins with the high-speed intake air flow flowing in the guide groove 21,
The atomization of the fuel spray is promoted, and the fuel spray is prevented from adhering to the intake passage wall surface 20 and forming a wall flow.

Since the wall flow of the fuel is prevented from being generated on the wall surface 20 of the intake passage in this way, the control response of the air-fuel ratio of the air-fuel mixture supplied to the combustion chamber is improved during the transition in which the fuel injection amount changes. Further, since atomization of the fuel is promoted, the emission can be improved and the fuel consumption can be reduced.

Further, under the operating condition in which the intake flow control valve 8 is closed, the high-speed intake flow collected in the guide groove 21 is linearly guided to the central portion of the combustion chamber 1, and the combustion chamber inclined to the pent roof type. Upon hitting the wall 18 and the valve face of the exhaust valve, a swirling flow swirling in the longitudinal direction is generated in the combustion chamber 1, as indicated by the arrow in FIG. The swirling flow generated in the combustion chamber 1 promotes the mixing of the fuel spray and the air, whereby good combustibility is obtained, and the lean burn region where the air-fuel ratio is diluted can be expanded.

Since each guide groove 21 is formed so that its center extension line is located closer to the center side of the cylinder than the center line of each intake valve, under the operating conditions in which the intake flow control valve 8 is closed, The air-fuel mixture is vertically swirled in the center of the combustion chamber 1, and the fuel is collected near the spark plug as the piston rises, so that the air-fuel mixture is stratified. As a result, good combustibility can be obtained, and the lean burn region where the air-fuel ratio is diluted can be expanded.

Further, the guide groove 24 is formed in the cylinder head 1.
It can be integrally formed at the time of casting 0, and it is possible to improve productivity by eliminating the need for drilling.

Next, another embodiment shown in FIGS. 5 and 6 will be described. 1 and 3 are denoted by the same reference numerals.

A V-shaped guide groove 21 is formed below the intake flow control valve 8 along the partition wall 26 on the intake passage wall surface 20 of the intake port 11, and two V-shaped guide grooves 23 are V-shaped. Is formed along the outside of the guide groove 21.

The inner guide groove 21 is used for the intake flow control valve 8
Linearly extending from the upstream side of the valve seat over the valve seat.
The inner guide groove 21 is formed such that its center extension line is located closer to the center side of the cylinder than the center line of each intake valve.

A concave portion 22 facing the injector 3 is formed on the upstream side of the inner guide groove 21. The concave portion 22 is arranged at a bent portion where the inclination angle of the guide groove 21 changes.

The outer guide groove 23 is the inner guide groove 21.
Extends parallel to. The outer guide groove 23 extends linearly from the upstream side of the intake flow control valve 8 to the valve seat. The outer guide groove 23 is formed so that the extension line of the center thereof is located on the side of the cylinder more than the center line of each intake valve.

With the above construction, the operation will be described below.

In the operating state in which the intake flow control valve 8 is opened, the intake flow control valve 8 does not restrict the flow of intake air, and the intake air is sucked into the combustion chamber 1 while being mixed with the fuel spray injected from the injector 3. , The air-fuel mixture is made uniform.

When the intake flow control valve 8 is closed in a predetermined low speed and low load region, most of the intake air is introduced into the guide grooves 21 and 23.
Pass each. The fuel injected from the injector 3 is injected to the upstream side of the inner guide groove 21 via the recess 22 and joins with the high-speed intake air flow flowing in the guide groove 21, thereby promoting atomization of the fuel spray. The fuel spray is prevented from adhering to the intake passage wall surface 20 and forming a wall flow.

Under the operating condition in which the intake flow control valve 8 is closed, the high-speed intake flow collected in the inner guide groove 21 is linearly guided to the central portion of the combustion chamber 1, and the combustion chamber is inclined in a pent roof type. The wall 18 and the valve face of the exhaust valve impinge on the combustion chamber 1 to generate a swirling flow that swirls in the vertical direction.

The inner guide groove 21 is formed so that the extension line of the center thereof is located closer to the center of the cylinder than the center line of each intake valve, so that the intake flow control valve 8 is closed under operating conditions. The air-fuel mixture that has passed through the inner guide groove 21 swirls vertically in the center of the combustion chamber 1.

On the other hand, the outer guide groove 23 is formed such that the extension line of the center thereof is located on the side of the cylinder with respect to the center line of each intake valve, so that the intake flow control valve 8 is closed. The fuel-free air that has passed through the outer guide groove 23 under the condition swirls vertically in the lateral portion of the combustion chamber 1.

Since the rich air-fuel mixture swirls in the central portion of the combustion chamber 1 as the piston descends in this manner, fuel is collected near the spark plug as the piston rises, and the stratification of the air-fuel mixture occurs. Is done. As a result, good flammability can be obtained, and the lean burn region can be expanded.

Next, another embodiment shown in FIG. 7 will be described. The parts corresponding to those in FIG. 3 are designated by the same reference numerals.

As shown in the sectional view taken along the line BB of FIG. 7, the valve body 15 of the intake flow control valve 8 is formed in the shape of a plate having an oval shape similar to the cross-sectional shape of the passage of the intake port 11, and two of them are formed on the upper portion thereof. The cutout portion 14 is formed.

The upstream portion of the guide groove 21 is arranged on the passage center line of the intake port 11. The two notches 14 are formed offset from the guide groove 21 to the side of the intake port 11. The two cutouts 14 are formed symmetrically with the guide groove 21 in between. The two notches 14 are the guide grooves 2
It is formed as far as possible from 1.

Similar to the embodiment shown in FIG. 1, the structure of the cylinder head 10 has two guide grooves 21 below the intake flow control valve 8 in the intake passage wall surface 20 of the intake port 11 in a V shape along the intake flow direction. Is formed. Guide groove 21
A concave portion 22 facing the injector 3 is formed on the upstream side of the.

With the above construction, the operation will be described below.

In the operating state in which the intake flow control valve 8 is opened, the intake flow control valve 8 does not restrict the flow of intake air, and the intake air is sucked into the combustion chamber 1 while being mixed with the fuel spray injected from the injector 3. , The air-fuel mixture is made uniform.

When the intake flow control valve 8 is closed in a predetermined low speed and low load region, most of the intake air passes through the guide groove 21 and the notch portion 14, respectively.

The fuel injected from the injector 3 is injected to the upstream side of the guide groove 21 through the recess 22 and joins with the high-speed intake air flow flowing in the guide groove 21,
The atomization of the fuel spray is promoted, and the fuel spray is prevented from adhering to the intake passage wall surface 20 and forming a wall flow.

Under the operating condition in which the intake flow control valve 8 is closed, the high-speed intake flow collected in the guide groove 21 is linearly guided to the central portion of the combustion chamber 1, and the combustion chamber wall 18 inclined in the pent roof type is formed. And, a swirling flow swirling in the vertical direction is generated in the combustion chamber 1 by striking the valve face of the exhaust valve.

Since each guide groove 21 is formed so that the extension line of its center is located closer to the center of the cylinder than the center line of each intake valve, the guide groove 21 is guided under operating conditions in which the intake flow control valve 8 is closed. The air-fuel mixture that has passed through the groove 21 swirls vertically in the center of the combustion chamber 1. On the other hand, since the cutouts 14 are formed symmetrically with the guide groove 21 interposed therebetween, the intake air containing no fuel that has passed through the cutouts 14 swirls vertically in the lateral portion of the combustion chamber 1. . Since the rich mixture swirls in the center of the combustion chamber 1 as the piston descends in this manner, fuel is collected near the spark plug as the piston rises, and stratification of the mixture occurs. Be seen. As a result, good flammability can be obtained, and the lean burn region can be expanded.

Next, another embodiment shown in FIGS. 8 and 9 will be described. 1 and 3 are denoted by the same reference numerals.

The intake flow control valve 8 is provided on the wall surface 20 of the intake passage.
One guide groove 24 extending from below to the one intake port 11 is formed.

The guide groove 24 extends from the upstream side of the intake flow control valve 8 to the valve seat. The guide groove 24 extends linearly along the partition wall 26.

A concave portion 22 facing the injector 3 is formed in the middle of the guide groove 24. The recess 22 becomes gradually deeper from the middle of the guide groove 24 to the upstream side. The recess 22 defines a space through which the fuel spray injected from the injector 3 passes.

The operation is as described above. Next, the operation will be described.

In the operating state in which the intake flow control valve 8 is opened, the intake flow control valve 8 does not restrict the flow of intake air, and the intake air is sucked into the combustion chamber 1 while being mixed with the fuel spray injected from the injector 3. It

When the intake air flow control valve 8 is closed in a predetermined low speed and low load region, most of the intake air is collected in the guide groove 24, and passes through the guide groove 24 from one intake port 11 to the combustion chamber 1. A swirl flow having a component that is sucked and laterally swirled in the combustion chamber 1 is generated. The swirling flow generated in the combustion chamber 1 promotes the mixing of the fuel spray and the air, whereby good combustibility is obtained, and the lean burn region where the air-fuel ratio is diluted can be expanded.

The fuel injected from the injector 3 is injected to the upstream side of the guide groove 24 through the concave portion 22 and joins with the high-speed intake air flowing through the guide groove 24.
Even if the spray angle of the injector 3 is set to be large, the fuel spray moves toward the combustion chamber 1 along the guide groove 24, the atomization of the fuel spray is promoted, and the fuel spray adheres to the wall surface 20 of the intake passage to form a wall flow. Prevent becoming.

Next, another embodiment shown in FIG. 10 will be described. The parts corresponding to those in FIG. 9 are denoted by the same reference numerals.

As shown in the sectional view taken along the line BB of FIG. 10, the valve body 15 of the intake flow control valve 8 is formed in the shape of a plate having an oval shape similar to the cross-sectional shape of the passage of the intake port 11, and 1 is formed on the upper portion thereof.
Two notches 13 are formed.

In the structure of the cylinder head 10, as in the embodiment shown in FIG. 8, one guide groove 24 extending linearly from below the intake flow control valve 8 to one intake port 11 is formed in the intake passage wall surface 20. It A recess 22 is formed on the upstream side of the guide groove 24, the recess 22 facing the injector 3.

The upstream portion of the guide groove 24 is arranged on the passage center line of the intake port 11. The notch 13 is the guide groove 2
4 is formed to be offset to the side of the intake port 11 from 4. The notch portion 13 is the intake port 1 in which the guide groove 24 extends.
It is formed on the same side as 1. The notch 13 has a guide groove 24.
Is formed as far away as possible from.

With the above arrangement, the operation will be described.

In the operating state in which the intake flow control valve 8 is opened, the intake flow control valve 8 does not throttle the flow of intake air, and is mixed with the fuel spray injected from the injector 3 and is sucked into the combustion chamber 1. , The air-fuel mixture is made uniform.

When the intake flow control valve 8 is closed in a predetermined low speed and low load region, most of the intake air passes through the guide groove 24 and the notch portion 13, respectively.

The fuel injected from the injector 3 is injected to the upstream side of the guide groove 24 through the recess 24, and joins with the high-speed intake air flow flowing in the guide groove 24.
The atomization of the fuel spray is promoted, and the fuel spray is prevented from adhering to the intake passage wall surface 20 and forming a wall flow.

Under the operating conditions in which the intake flow control valve 8 is closed, the high-speed intake flow collected in the guide groove 24 becomes the guide groove 2
4 is sucked into the combustion chamber 1 from one of the intake ports 11 to generate a swirling flow having a lateral swirling component in the combustion chamber 1. The high-speed intake air flow passing through the notch portion 13 is also used as the guide groove 2.
4 is sucked into the combustion chamber 1 through the intake port 11 in which the swirl flow having a lateral swirling component is generated.

By thus strengthening the force of the swirl flow generated in the combustion chamber 1, mixing of the fuel spray and air is promoted, good combustibility is obtained, and the lean burn region can be expanded. .

Next, another embodiment shown in FIGS. 11 and 12 will be described. 1 and 3 are denoted by the same reference numerals.

In the cylinder head 10, two V-shaped intake ports 11 and one exhaust port 19 are formed.

The combustion chamber wall 18 has one intake port 11
The exhaust port 19 is open to face the other side, and the spark plug (not shown) faces the other intake port 11. A boss portion 17 to which an ignition plug is attached is formed in the cylinder head 10 adjacent to the exhaust port 19.

The intake flow control valve 8 is provided on the wall surface 20 of the intake passage.
One guide groove 24 extending from below to one intake port 11 is linearly formed. A recess 22 is formed on the upstream side of the guide groove 24, the recess 22 facing the injector 3.

As shown in the sectional view taken along the line BB of FIG. 12, the valve body 15 of the intake flow control valve 8 is formed in the shape of a plate having an oval shape similar to the cross-sectional shape of the passage of the intake port 11, and 1 is formed on the upper portion thereof.
Two notches 27 are formed.

The upstream portion of the guide groove 24 is arranged on the passage center line of the intake port 11. The notch 27 is the guide groove 2
4 is formed to be offset to the side of the intake port 11 from 4. The notch portion 27 is the intake port 1 through which the guide groove 24 extends.
It is formed on the side opposite to 1. The notch 27 is the guide groove 24.
Is formed as far away as possible from.

The structure is as described above. Next, the operation will be described.

In the operating state in which the intake flow control valve 8 is opened, the intake flow control valve 8 does not throttle the flow of intake air, and the intake air is sucked into the combustion chamber 1 while being mixed with the fuel spray injected from the injector 3. , The air-fuel mixture is made uniform.

When the intake flow control valve 8 is closed in a predetermined low speed and low load region, most of the intake air passes through the guide groove 24 and the cutout portion 27.

The fuel injected from the injector 3 is injected to the upstream side of the guide groove 24 through the recess 24, and joins with the high-speed intake air flow flowing in the guide groove 24.
The atomization of the fuel spray is promoted, and the fuel spray is prevented from adhering to the intake passage wall surface 20 and forming a wall flow.

In the operating state in which the intake flow control valve 8 is closed, substantially the same amount of intake air passes through the guide groove 24 and the cutout portion 27, respectively. The high-speed intake air flow containing the fuel collected in the guide groove 24 passes through the guide groove 24 and one intake port 11
Is sucked into the combustion chamber 1 to generate a swirling flow in the combustion chamber 1 which vertically swirls. A high-velocity intake flow containing no fuel passing through the cutout portion 27 flows from the other intake port 11 to the combustion chamber 1
And is swirled into the combustion chamber 1 in the vertical direction.

As the piston descends in this manner, the rich air-fuel mixture swirls in the side portion of the combustion chamber 1. Therefore, as the piston rises, fuel is collected in the vicinity of the spark plug. Stratification is performed. As a result, good combustibility can be obtained, and the lean burn region where the air-fuel ratio is diluted can be expanded.

Next, another embodiment shown in FIGS. 13 and 14 will be described. 1 and 3 are denoted by the same reference numerals.

Three intake ports 11 are formed in the cylinder head 10 in a branched manner, and two exhaust ports 19 are provided.
Are branched and formed. The spark plug faces the center of the combustion chamber 1.

Intake port 1 with one guide groove 28 at the center
1 is formed. The guide groove 11 is used for the intake flow control valve 8
Extends linearly from below to the valve seat. The guide groove 28 is formed such that its center is located at the center of the cylinder.

A concave portion 22 facing the injector 3 is formed on the upstream side of the inner guide groove 28. The recess 22 is arranged at a bent portion where the inclination angle of the guide groove 28 changes.

With the above arrangement, the operation will be described below.

In the operating state in which the intake flow control valve 8 is open, the intake flow control valve 8 does not throttle the flow of intake air, and is sucked into the combustion chamber 1 while being mixed with the fuel spray injected from the injector 3. , The air-fuel mixture is made uniform.

When the intake flow control valve 8 is closed in a predetermined low speed and low load range, most of the intake air passes through the guide groove 28. The fuel injected from the injector 3 is injected to the upstream side of the guide groove 28 via the recess 22 and joins with the high-speed intake air flow flowing in the guide groove 28, whereby atomization of the fuel spray is promoted and The spray is prevented from adhering to the wall surface 20 of the intake passage and forming a wall flow.

Under the operating condition in which the intake flow control valve 8 is closed, the high-speed intake flow collected in the guide groove 28 is linearly guided to the central portion of the combustion chamber 1, and the combustion chamber wall 18 inclined to the pent roof type is formed. And, a swirling flow swirling in the vertical direction is generated in the combustion chamber 1 by striking the valve face of the exhaust valve.

Since the rich air-fuel mixture swirls in the central portion of the combustion chamber 1 as the piston descends in this manner, fuel is collected near the spark plug as the piston ascends. Is done. As a result, good flammability can be obtained, and the lean burn region can be expanded.

Next, another embodiment shown in FIGS. 15, 16 and 17 will be described. In this embodiment, the present invention is applied to an engine in which the injector 3 is provided above the intake port 11. The parts corresponding to those in FIGS. 1, 2 and 3 are designated by the same reference numerals.

Two intake ports 11 and two exhaust ports 19 are opened in the combustion chamber wall 18 so as to face each other with the spark plug interposed therebetween.

The intake flow control valve 8 is provided on the wall surface 20 of the intake passage.
Two guide grooves 29 are formed in the upper part of the drawing along the intake air flow direction. When the intake flow control valve 8 is closed, most of the intake air is linearly guided to the combustion chamber 1 through the respective guide grooves 29, so that an intake swirl flow is generated in the combustion chamber 1.

Each guide groove 29 extends linearly from the upstream side of the intake flow control valve 8 to the valve seat. Each guide groove 29 extends in a V shape so as to sandwich the partition wall 26.

Each guide groove 29 is formed such that its center extension line is located closer to the center of the cylinder than the center line of each intake valve.

A concave portion 22 facing the injector 3 is formed in the middle of the guide groove 29.

With the above arrangement, the operation will be described.

In the operating state in which the intake flow control valve 8 is opened, the intake flow control valve 8 does not restrict the flow of intake air, and the intake air is sucked into the combustion chamber 1 while being mixed with the fuel spray injected from the injector 3. , The air-fuel mixture is made uniform.

When the intake flow control valve 8 is closed in a predetermined low speed and low load region, most of the intake air is collected in the guide groove 29, and the fuel injected from the injector 3 is guided in the guide groove 29.
By merging with the high-speed intake air flow flowing through, the atomization of the fuel spray is promoted and the fuel spray is prevented from adhering to the intake passage wall surface 20 and forming a wall flow.

Under the operating condition that the intake flow control valve 8 is closed, the high-speed intake flow collected in the guide groove 29 is linearly guided to the central portion of the combustion chamber 1 and is vertically introduced into the combustion chamber 1. A swirling flow is generated. The swirling flow generated in the combustion chamber 1 promotes the mixing of the fuel spray and the air, whereby good combustibility is obtained, and the lean burn region where the air-fuel ratio is diluted can be expanded.

[0141]

As described above, in the intake system for the internal combustion engine according to the first aspect of the present invention, in the operating state in which the intake flow control valve is closed, the fuel spray injected from the injector by the intake flow velocity flowing through the guide groove is injected. Atomization is promoted, and fuel spray is prevented from adhering to the wall surface of the intake passage to form a wall flow, improving the air-fuel ratio control response during transients, improving emissions, and reducing fuel consumption. Be peeled off.

The intake system for an internal combustion engine according to claim 2 is
In the operating state in which the intake flow control valve is closed, the fuel injected from the injector through the recess to the upstream side of the guide groove merges with the high-speed intake flow flowing in the guide groove,
The atomization of the fuel spray is promoted, and the fuel spray is prevented from adhering to the wall surface of the intake passage to form a wall flow, and good combustibility is obtained.

An intake system for an internal combustion engine according to claim 3 is
Since a V-shaped guide groove is formed in each intake port that is V-shaped, most of the intake air swirls vertically in the combustion chamber when the intake flow control valve is closed and most of the intake air passes through the guide groove. A swirling flow is generated, and good combustibility is obtained.

An intake system for an internal combustion engine according to claim 4 is
Under operating conditions where the intake flow control valve is closed, the high-speed air flow containing no fuel that has passed through the outer guide groove swirls vertically in the side part of the combustion chamber, creating a rich mixture in the center part of the combustion chamber. Because of the turning, the air-fuel mixture is stratified and the lean burn region where the air-fuel ratio is diluted can be expanded.

The intake system for an internal combustion engine according to claim 5 is
In the operating state where the intake flow control valve is closed, the high-speed intake flow containing the fuel collected in the guide groove creates a swirling flow that vertically swirls in the center of the combustion chamber, while the fuel that has passed through the notch Since a high-speed air flow that does not include a swirl flow that vertically swirls in the side portion of the combustion chamber, stratification of the air-fuel mixture is performed, and the lean burn region can be expanded.

The intake system for an internal combustion engine according to claim 6 is
Due to the structure in which one guide groove is formed in one intake port branched into a V shape, a swirl flow having a swirl component in the lateral direction is generated in the combustion chamber in the operating state in which the intake flow control valve is closed, which is good. Good flammability is obtained.

The intake system for an internal combustion engine according to claim 7 is:
The guide groove extends for the same intake port,
Due to the structure in which the cutout part formed in the intake flow control valve is directed, most of the intake air passes through the guide groove and the cutout part in the operating state with the intake flow control valve closed, and from the same intake port to the combustion chamber. By the inflow, the force of the swirling flow having a swirling component in the lateral direction generated in the combustion chamber is strengthened, and good combustibility is obtained.

An intake system for an internal combustion engine according to claim 8 is
Since the guide groove extends to one intake port and the notch formed in the intake flow control valve is directed to the other intake port, the rich mixture swirls in the side part of the combustion chamber, The fuel mixture is collected in the vicinity of the spark plug facing the side portion of the combustion chamber, and the air-fuel mixture is stratified, so that the lean burn region can be expanded.

An intake system for an internal combustion engine according to claim 9 is
With the structure in which three intake ports are branched and one guide groove is linearly formed in the central intake port, the air-fuel mixture is stratified and the lean burn region can be expanded.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of an engine showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the same engine.

FIG. 3 is a line AA, line BB, line CC of FIG.
Sectional drawing which follows each DD line.

FIG. 4 is a flow velocity distribution diagram of intake air.

FIG. 5 is a plan cross-sectional view of an engine showing another embodiment.

FIG. 6 is a line AA, line BB, line CC of FIG.
Sectional drawing which follows each DD line.

FIG. 7 is a line AA in FIG. 1 showing still another embodiment,
Sectional drawing which follows each of BB line, CC line, and D-D line.

FIG. 8 is a plan sectional view of an engine showing still another embodiment.

9 is a line AA, line BB, line CC in FIG.
Sectional drawing which follows each DD line.

FIG. 10 is a sectional view taken along line AA of FIG. 8 showing still another embodiment.
Sectional drawing which follows each of a line, a BB line, a CC line, and a D-D line.

FIG. 11 is a plan sectional view of an engine showing still another embodiment.

FIG. 12 is a line AA, a line BB, and a line CC in FIG.
Sectional drawing which follows each of a line and DD line.

FIG. 13 is a plan sectional view of an engine showing still another embodiment.

14 is a line AA, a line BB, and a line CC in FIG.
Sectional drawing which follows each of a line and DD line.

FIG. 15 is a plan cross-sectional view of an engine showing still another embodiment.

FIG. 16 is a cross-sectional view of the same engine.

17 is a line AA, a line BB, and a line CC in FIG.
Sectional drawing which follows each of a line and DD line.

FIG. 18 is a cross-sectional view of an engine showing a conventional example.

[Explanation of symbols]

 1 Combustion Chamber 3 Injector 4 Piston 8 Intake Flow Control Valve 10 Cylinder Head 11 Intake Port 13 Notch 14 Notch 18 Combustion Chamber Wall 20 Intake Passage Wall 21 Guide Groove 22 Recess 23 Guide Groove 24 Guide Groove 27 Notch 28 Guide groove 29 Guide groove

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F02M 69/04 F02M 69/04 R 69/00 350W

Claims (9)

[Claims] Claim: What is claimed is: 1. An intake passage for guiding intake air to a combustion chamber, an intake flow control valve for narrowing the intake passage according to operating conditions, and a groove recessed in a wall surface of the intake passage for intake air when the intake flow control valve is closed. An intake device for an internal combustion engine, comprising: a guide groove that passes through; and an injector that faces the guide groove and injects fuel into an intake passage. 2. The intake system for an internal combustion engine according to claim 1, wherein a recess facing the injector is formed on the upstream side of the guide groove. 3. The two intake ports connected to the combustion chamber are formed by branching in a V shape, and the two guide grooves are formed by branching in a V shape in each intake port. Alternatively, the intake device for an internal combustion engine according to item 2. 4. An injector is made to face the V-shaped branched guide groove, and a V-shaped guide groove is formed so as to sandwich the V-shaped guide groove in each intake port. An intake system for an internal combustion engine as described. 5. An injector is made to face the V-shaped branched guide groove, and a cutout portion is formed in the intake flow control valve for passing intake air when the valve is closed. The cutout portion is located on the side of the intake port with respect to the guide groove. The intake system for an internal combustion engine according to claim 3, wherein the intake system is formed by offsetting. 6. The method according to claim 1 or 2, wherein two intake ports connected to the combustion chamber are formed by branching in a V shape, and one guide groove is formed toward one intake port. An intake system for an internal combustion engine as described. 7. The intake flow control valve according to claim 6, wherein a cutout portion for allowing intake air to pass through when the valve is closed is formed, and the cutout portion is formed toward an intake port where a guide groove extends. Intake device for internal combustion engine. 8. The intake flow control valve is formed with a cutout portion through which intake air is passed when the intake valve is closed, and the cutout portion is formed toward an intake port different from an intake port through which the guide groove extends. Item 7. An intake device for an internal combustion engine according to item 6. 9. The method according to claim 1, wherein three intake ports connected to the combustion chamber are formed in a branched manner, and one guide groove is linearly formed in the central intake port. Intake device for internal combustion engine.