JPH1162593A - Cylinder injection type spark ignition internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain satisfactory combustion with high efficiency even when a bore diameter is small. SOLUTION: In this type of spark ignition engine, a fuel injection valve 22 is operated for injecting fuel against intaken air flow 100 along a recession 16 guided thereby toward an ignition plug 90, when at least a piston 12 during compressive process almost reaches a top dead center. Fuel particles 102 injected from the fuel injection valve are decelerated by the intaken air flow guided by the recession 16. Time for atomization until ignition can be sufficiently secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct injection type spark ignition type internal combustion engine mounted on a vehicle, and more particularly to a direct injection gasoline engine having a small displacement.

[0002]

2. Related Background Art In recent years, in a spark ignition type internal combustion engine mounted on a vehicle, fuel is directly injected into a combustion chamber in place of a conventional intake pipe injection type in order to reduce harmful exhaust gas components and improve fuel efficiency. Various types of in-cylinder injection type gasoline engines have been proposed, and examples thereof are described in, for example, JP-A-4-166612 and JP-A-5-240044.
And Japanese Patent Application Laid-Open No. H08-035429.

In the cylinder injection gasoline engine disclosed in each of the above publications, a cavity (recess) is provided at the top of the piston, and a small amount of fuel is injected into the cavity, for example, from a fuel injection valve during a compression stroke. Even at the time of ignition, an air-fuel mixture having an air-fuel ratio close to the stoichiometric air-fuel ratio is generated around the ignition plug (ignition plug) by the intake air flow (swirl flow) flowing over the cavity in the same direction as the fuel injection direction. It is possible.

Therefore, in the cylinder injection gasoline engine, it is possible to ignite even at a lean air-fuel ratio as a whole and to realize stratified combustion with high combustion efficiency. It is possible to reduce the emission of harmful exhaust gas components such as CO) and hydrocarbons (HC), and to improve the fuel efficiency mainly during idling operation or low load driving.

[0005]

In the direct injection gasoline engine disclosed in each of the above publications, the fuel injection valve is arranged near the cylinder wall on the intake port side so as to inject fuel obliquely toward the combustion chamber. The ignition plug is disposed substantially at the center of the cylinder so as to be substantially upright facing the combustion chamber. The cavity at the top of the piston is formed so that the fuel injected from the fuel injection valve reaches the vicinity of the ignition plug together with the swirling flow according to the positions of the fuel injection valve and the spark plug.

However, such an arrangement of the fuel injection valve and the spark plug is good when the displacement of the engine is large and the bore diameter of the cylinder is relatively large, but the displacement of the engine is small and the bore of the cylinder is small. When the diameter is small, the distance from the fuel injection valve to the spark plug becomes shorter,
There is a problem that a sufficient atomization time cannot be obtained until the injected fuel reaches the spark plug, so that good combustion cannot be realized and the combustion efficiency is reduced.

In order to increase the atomization time, it is conceivable to lower the fuel injection pressure to lower the speed of the fuel particles in an engine having a small bore diameter. In view of fuel injection, it is not preferable to lower the fuel injection pressure. In addition, when the fuel injection pressure is reduced in this way, atomization of the fuel, that is, promotion of atomization of the fuel spray, is promoted. May be hindered.

The present invention has been made in view of the above circumstances, and has as its object the in-cylinder injection type spark capable of realizing good combustion with high combustion efficiency even when the bore diameter is small. It is to provide an ignition type internal combustion engine.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, the fuel injection valve is provided in the recess toward the spark plug at least when the piston is near the top dead center during the compression stroke. Is provided so as to inject fuel along the flow of the intake air guided by the recess, so that the velocity of the fuel particles injected from the fuel injection valve is pushed by the flow of the intake air guided by the recess. As a result, a sufficient atomization time is secured before the fuel reaches the spark plug. Therefore, even in an internal combustion engine having a small displacement and a small bore diameter, the fuel is sufficiently atomized and concentrated in the vicinity of the ignition plug while promoting the atomization of the fuel spray without lowering the fuel injection pressure. And stratified combustion with good and high combustion efficiency is realized.

[0010] Even in an internal combustion engine having a large bore diameter, by injecting fuel in opposition to the flow of intake air, atomization of fuel spray is promoted while maintaining the speed of fuel particles constant. It is possible to further increase the fuel injection pressure as much as possible. In other words, by injecting the fuel in opposition to the flow of the intake air, even if the fuel injection pressure is increased, it is possible to prevent the fuel spray from adhering to the cylinder wall beyond the spark plug, and to prevent smoke. It is possible to realize stratified combustion with even higher combustion efficiency without occurrence of cracks.

According to the second aspect of the present invention, the position of the ignition plug and the shape of the intake port are the same as those of the conventional intake pipe injection type internal combustion engine, but the concave portion satisfactorily injects the intake air. Since the fuel injection valve is formed at the top of the piston so as to be able to be guided toward the valve and the fuel injection valve is appropriately disposed so as to be able to inject fuel in opposition to the flow of intake air along the concave portion, the displacement is small, and In a small internal combustion engine, an in-cylinder injection type spark ignition type internal combustion engine having high combustion efficiency can be easily realized without largely changing the structure of the cylinder head as compared with the conventional internal combustion engine.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, there is shown a longitudinal sectional view of a SOHC (single overhead camshaft) type direct injection gasoline engine according to the present invention mounted on a vehicle. Referring to FIG. 2, a rocker cover is removed. FIG. 1 is a top view of a direct injection gasoline engine in a state, and an SO according to the present invention will be described below with reference to FIGS.
The configuration of the HC type direct injection gasoline engine will be described in detail. The SOHC in-cylinder gasoline engine is, for example, a four-valve four-cylinder gasoline engine having a small displacement, and all four cylinders can perform fuel injection not only in the intake stroke but also in the compression stroke. Here, one of the four cylinders will be described as a representative.

As shown in FIG. 1, an SOHC type direct injection gasoline engine (hereinafter simply referred to as an engine) 1 has a cylinder head 4 and a rocker cover 6 on a cylinder block 2 in the same manner as a normal gasoline engine. Each of them is placed in order and fixed by a bolt or the like.
As shown in the figure, a piston 12 is inserted into a cylindrical cylinder 10 of the cylinder block 2. The piston 12 is connected to a crankshaft (not shown) via a connecting rod 14, and reciprocates by sliding in the cylinder 10 according to rotation of the crankshaft. The bore diameter of the cylinder 10 and the piston 12 is relatively small because the engine 1 has a small displacement.

On the top surface of the piston 12, a cavity (recess) 16 is formed. More specifically, the cavity 16 is formed by the cylinder 1 on the top surface of the piston 12.
0, that is, a portion on one side of a base surface (plane) including a cylinder axis X and a center line Y (see FIG. 2) of the engine 1 connecting the center axes of the respective cylinders is curved into a hemispherical shape. When the piston 12 is at the top dead center, one edge 16a of the cavity 16 is located near an injection portion (injection port) 22a of the fuel injection valve 22 described later, and the other edge 16b
Are formed in the vicinity of a spark generating portion 90a of a spark plug 90 described later.

On the other hand, the fuel injection valve (injector) 22 is provided in the cylinder head 4 by directly injecting fuel toward a combustion chamber 20 formed by being divided by the lower surface of the cylinder head 4 and the top surface of the piston 12. Is provided. More specifically, the fuel injection valve 22 is provided at a position corresponding to the vicinity of the outer peripheral wall of the cylinder 10 by the injection unit 22a.
0, and is attached to the cylinder head 4 with bolts 23 at a predetermined angle so that fuel can be injected obliquely to the cylinder axis X when viewed from the center line Y direction. . The predetermined angle is an angle at which fuel can be injected along the bottom surface of the cavity 16 when the piston 12 is near the top dead center. The allowable fuel injection pressure of the fuel injection valve 22 is set to a high pressure (e.g., during the compression stroke in which the pressure in the combustion chamber 20 becomes high). 50 kgf / cm ² or more).

A cam shaft 30 is rotatably supported on the cylinder head 4 along the center line Y. Specifically, the camshaft 30 includes a plurality of shaft support portions 32 formed between the cylinders and at both ends of the cylinder head 4.
The cylinder head 4 is rotatably supported by the cylinder head 4 while being held by cam caps 34 provided corresponding to the support portions 32. The cam cap 34 is fixed to the support 32 with a pair of bolts 38, 38, respectively.

Further, a pair of intake ports 44 are formed in the cylinder head 4. Specifically, a pair of intake ports 40 are formed on the lower surface of the cylinder head 4 at one side of the base surface.
The lower ends (one ends) of the pair of intake ports 40,
At 40, the cylinder head 4 is opened so as to face the combustion chamber 20, while each upper end (the other end) is opened at the side surface of the cylinder head 4 in the same manner as a normal intake pipe injection type internal combustion engine. That is, the intake ports 44 are arranged so that the intake air can flow into the combustion chamber 20 toward the base surface.

The cylinder head 4 is also formed with a pair of exhaust ports 46,46. For more information,
A pair of exhaust ports 42, 42 are formed on the lower surface of the cylinder head 4 at the other side of the base surface, and one end of each of the exhaust ports 46, 46 has one end thereof.
2, the other end is also open on the side surface of the cylinder head 4 while opening toward the combustion chamber 20.

The intake ports 40, 40 are provided with a pair of intake valves 50, 50 for opening and closing the communication between the intake ports 44, 44 and the combustion chamber 20, while the exhaust port 4 is provided.
A pair of exhaust valves 52, 52 for communicating and shutting off the exhaust ports 46, 46 and the combustion chamber 20 are provided in the exhaust ports 2, 42. As shown in the figure, the intake valves 50, 50 and the exhaust valves 52, 52 also have a cylinder axis X, based on the positional relationship between the intake ports 44, 44 and the exhaust ports 46, 46.
And the base surface including the center line Y is provided on the cylinder head 4. Specifically, these intake valves 5
0, 50 and the exhaust valves 52, 52 each have a predetermined angle with respect to the base surface when viewed from the center line Y direction, that is, the intake valves 50, 50 and the exhaust valves 52, 52 As shown in FIG. 1, the cylinder head 4 extends so as to be separated from each other.

Incidentally, the intake valves 50, 50 and the exhaust valves 52, 52 are not special, but are similar to those normally used in an internal combustion engine. Therefore, the spring seats 54, 54 and the spring seats 5 are respectively provided on the heads of the intake valves 50, 50 and the exhaust valves 52, 52.
6, 56 are provided, and these spring seats 5
Coil springs 6, 54, and spring seats 56, 56 and the cylinder head 4, the intake valves 50, 50 and the exhaust valves 52, 52 are fitted around the coil springs 6, respectively.
0, 60 and coil springs 62, 62 are contracted. Therefore, usually, the intake valves 50, 50 and the exhaust valves 52, 5
Reference numeral 2 denotes a state in which the intake ports 40, 40 and the exhaust ports 42, 42 are closed by being urged by the coil springs 60, 60 and the coil springs 62, 62. Reference numerals 64 and 66 in FIG. 1 denote valve guides for the intake valve 50 and the exhaust valve 52, respectively.
50, the exhaust valves 52, 52 can be slid smoothly along the valve guides 64, 66 at the above-mentioned predetermined angle and can be opened and closed well.

The camshaft 30 has a pair of cam portions 30a, 30a and a cam portion 30b corresponding to the intake valves 50, 50 and the exhaust valves 52, 52, respectively.
Are formed. Then, these cam portions 30a, 30
and a T-shaped rocker arm 70 is provided between the cam portion 30b and the exhaust valves 52, 50a.
A rocker arm 72 having a Y-shape is provided between the arm 52 and the rocker arm 52.

More specifically, as shown in FIG. 2, a rocker shaft 74 and a rocker shaft 76 are supported by the cam cap 34 in parallel with the camshaft 30.
The rocker arm 70 and the rocker arm 72 are swingably supported by the rocker shaft 74 and the rocker shaft 76, respectively. As for the rocker arm 70, a pair of rollers 80, 80 provided at one end of the rocker arm 70 contact the cam portions 30a, 30a, respectively, and a pair of valve adjusters 8 provided at the other end.
The distal ends of the intake valves 4 and 84 are disposed so as to abut against the heads of the intake valves 50 and 50, respectively. In addition, rocker arm 7
With respect to 2, the roller 82 provided at one end of the rocker arm 72 is in contact with the cam portion 30b, while the tips of a pair of valve adjusters 86 provided at the other end are the heads of the exhaust valves 52, 52. The parts are arranged so as to abut each other.

Therefore, when the camshaft 30 rotates,
The rocker arm 70 and the rocker arm 72 swing around the rocker shafts 74 and 76 according to the shapes of the cam portions 30a and 30a and the cam portion 30b.
0, 50 and the exhaust valves 52, 52 are coil springs 6
0, 60, the opening / closing operation is performed against the urging force of the coil springs 62, 62.

The cylinder head 4 has a combustion chamber 20.
The ignition plug (ignition plug) 90 is disposed so as to project the spark generating portion 90a substantially at the center of the combustion chamber 20, that is, at the ignition position where the air-fuel mixture in the combustion chamber 20 can be burned most effectively. More specifically, as shown in FIG.
It is attached to the cylinder head 4 at a predetermined angle with respect to the cylinder axis X when viewed from the center line Y direction. The predetermined angle is such that the ignition plug 90 is connected to the exhaust valves 52, 52, the camshaft 30, and the rocker shaft. It is set at an angle that allows it to be inserted and attached through the space 76. That is, FIG.
Referring to FIG. 2, a straight tube, that is, a guide tube 94 is provided, which functions as an insertion guide for the ignition plug 90 and prevents lubricating oil scattered in the cylinder head 4 from adhering to the ignition plug 90. A guide tube 94 is inserted between the exhaust valves 52, 52, the camshaft 30 and the rocker shaft 76 at the above-mentioned predetermined angle, and is fixed to a member of the cylinder head 4. In addition,
As described above, since the rocker arm 72 has a Y-shape, the guide tube 94 includes a pair of arm portions 73, 73.
Are arranged without interference with the rocker arm 72.
The upper end of the guide tube 94 is detachably fitted to the rocker cover 6 via an oil seal 96.

FIG. 3 shows the operation and effect of the SOHC type direct injection gasoline engine constructed as described above.
This will be described with reference to FIG. Here, a case where the fuel is injected in the compression stroke will be described. In the intake stroke, when intake is performed through intake ports 44, 44 as the piston 12 descends, the intake air flows into the combustion chamber 20 toward the base surface including the cylinder axis X.

Thereafter, the process proceeds to the compression stroke, in which the piston 12
Rises, the intake air is wound up with the rise. At this time, the intake air flows along the curved bottom surface of the cavity 16 provided on the top surface of the piston 12 and substantially from the center of the combustion chamber 20, that is, from the base surface side, as indicated by an arrow in FIG. It flows toward the injection part 22a of the valve 22. Then, the intake air is swirled in the cavity 16 as a flow that swirls in the cylinder 10 in the vertical direction, that is, a vortex positive tumble flow 100.

When the piston 12 reaches the vicinity of the top dead center, as shown in FIG. 3, fuel flows from the fuel injection valve 22 along the curved bottom surface of the cavity 16 and in the forward tumble flow 100.
The fuel is mixed with the intake air in the cavity 16 to become a fuel spray 102 and reaches the spark generating portion 90 a of the spark plug 90. By the way, in this way, the fuel flows in the opposite direction to the normal tumble flow 100,
In other words, when injected so as to oppose the flow of intake air,
The outflow velocity of the injected fuel particles is reduced by the forward tumble flow 100. That is, when the fuel is injected from the fuel injection valve 22 at a predetermined fuel pressure, when the fuel particles reach the distance after a predetermined time, the fuel is injected without tumbling, or the fuel is injected along the reverse tumble flow as in the related art. It will be shorter than the case.

That is, referring to FIG. 4, when the tumble flow is a reverse tumble flow (broken line), a forward tumble flow (solid line), and no tumble flow (dashed line), the fuel particle outflow velocity V from the fuel injection point S is measured. The time change is shown, and the fuel movement distance D at the outflow velocity V is also shown. As shown in the figure, the fuel is injected in the opposite direction to the forward tumble flow. Then, the degree of decrease in the fuel particle outflow velocity V is made larger than when the fuel is injected along the reverse tumble flow, and therefore, the movement distance D of the injected fuel particles is made smaller as a whole. For example, the fuel injected after a lapse of t1 from the fuel injection time S moves the distance D2 when injected along the reverse tumble flow, but on the other hand, when injected against the forward tumble flow. Moves only the distance D1.

Referring to FIG. 3, for example, the distance D1
Is equal to the area of the OSA'-A region (shaded area) in the figure when the fuel amount reaches the reverse tumble flow, while it is O- in the figure when the fuel amount reaches the forward tumble flow. The area is indicated by the area of the SB′-B area (shaded area). Comparing these areas, the area of the OSB'-B area (shaded area) is smaller than the area of the OSA'-A area (shaded area), that is, the tumble flow. It can be seen that the amount of fuel traveling the distance D1 is smaller when the flow is a normal tumble flow than when the flow is a reverse tumble flow.

This means that the distance D1 is equal to the fuel injection valve 2
Assuming that the distance is from the second injection portion 22a to the spark generation portion 90a of the ignition plug 90 located substantially at the center of the combustion chamber 20, when the fuel is injected in opposition to the positive tumble flow, a certain amount This means that even if an amount of fuel is injected, it takes more time until the fuel reaches the vicinity of the spark generating portion 90a as compared with the case where the fuel is injected along the reverse tumble flow. That is, it is shown that the fuel atomization time can be increased by injecting the fuel in opposition to the normal tumble flow.

Accordingly, even when the engine 1 has a small displacement and a small bore diameter, and the distance from the injection part 22a to the spark generation part 90a is as short as the distance D1, for example, the correctness is obtained as described above. By injecting the fuel in opposition to the tumble flow 100, it is possible to obtain a sufficient atomization time until the fuel reaches the spark generating portion 90a, and to sufficiently spray the fuel near the spark generating portion 90a during ignition. This makes it possible to obtain good combustion by allowing the fuel spray 102 to be present.

When the fuel reaches the spark generating portion 90a of the spark plug 90 in a state where the fuel is substantially confined in the cavity 16 and layered, even if the fuel injection amount is small, that is, the air-fuel ratio as a whole is Is lean
Even in the vicinity of the spark generating portion 90a, the air-fuel ratio is set to a relatively high (stoichiometric air-fuel ratio or rich) state. Therefore, when the piston 12 is further moved to the vicinity of the top dead center thereafter, the ignition is performed by the spark plug 90. However, the ignitability is good around the spark generating portion 90a,
Therefore, extremely good and efficient combustion, that is, stratified combustion is realized without occurrence of misfire (lean misfire) or the like. The operation and effect of stratified combustion are known, and a detailed description thereof is omitted here.

As described above, the direct injection gasoline engine according to the present invention has the cavity 16 on the upper surface of the piston 12 and
Is generated, and fuel is injected from the fuel injection valve 22 so as to face the positive tumble flow 100. Therefore, even in the case of an internal combustion engine having a small displacement and a small bore diameter, when the fuel is injected in the compression stroke, the time for atomizing the fuel is sufficiently secured and the ignition plug 90
The fuel spray 102 in the appropriate atomized state having a high air-fuel ratio can be suitably concentrated around the fuel cell, and stratified combustion can be realized extremely favorably without misfire or the like. As a result, in an internal combustion engine with a small displacement and a small bore diameter, the generation of harmful exhaust gas components such as hydrocarbons (HC) and carbon monoxide (CO) is suppressed to a low level, and the high combustion efficiency of the cylinder is improved. An internal injection gasoline engine can be realized.

In the direct injection gasoline engine according to the present invention, the position of the ignition plug 90 and the intake ports 44, 4
4 is made similar to that of a conventional intake pipe injection type internal combustion engine. Therefore, without largely changing the structure of the cylinder head 4 from the conventional one,
A direct injection gasoline engine with high combustion efficiency can be easily realized while reducing costs.

In the above embodiment, the SOHC type direct injection gasoline engine has been described. However, the valve operating mechanism may be of any type, for example, a DOHC type direct injection gasoline engine having a small displacement and a small bore diameter. However, the present invention can be applied favorably. In addition, the present invention is not limited to an internal combustion engine having a small bore, but may be applied to an internal combustion engine having a large bore. In this case,
By injecting fuel from the fuel injection valve so as to face the normal tumble flow, it is possible to increase the fuel injection pressure and promote atomization of the fuel spray. That is, when the fuel injection pressure is increased,
There is a risk that the speed of the fuel particles may increase and the fuel spray may adhere to the cylinder wall beyond the ignition plug. However, if the fuel is injected against the positive tumble flow, the speed of the fuel particles may be reduced. Is maintained at a constant speed, such adhesion of fuel spray can be prevented, and stratified combustion with higher combustion efficiency can be realized without generation of smoke or the like.

Further, in the above-described embodiment, the fuel injection valve 22 is configured to inject fuel opposite to the forward tumble flow. However, the invention is not limited to this, and the intake port 44 may be provided with the upright port extending substantially along the cylinder axis X. As a result, a reverse tumble flow is generated in the combustion chamber 20 in a direction opposite to the forward tumble flow, and the spark plug 90 and the fuel injection valve 22 are disposed so as to be opposite to each other. You may comprise so that fuel may be injected opposing a tumble flow. Also according to this, the same effect as in the above embodiment can be obtained.

[0037]

As described above in detail, according to the in-cylinder injection spark ignition type internal combustion engine of the first aspect of the present invention, the velocity of the fuel particles injected from the fuel injection valve during the compression stroke. Can be decelerated by the flow of the intake air which is opposed to the fuel injection direction and guided by the concave portion, and a sufficient atomization time can be secured until the fuel reaches the ignition plug. Therefore, even in an internal combustion engine having a small displacement and a small bore diameter, the fuel is sufficiently atomized and concentrated in the vicinity of the ignition plug while promoting the atomization of the fuel spray without lowering the fuel injection pressure. And good stratified combustion with high combustion efficiency can be realized.

Further, even in an internal combustion engine having a large bore diameter, it is possible to increase the fuel injection pressure without generating smoke or the like to promote the atomization of fuel spray, thereby realizing stratified combustion with higher combustion efficiency. can do. According to the in-cylinder injection type spark ignition type internal combustion engine of the second aspect, in an internal combustion engine having a small displacement and a small bore diameter, the structure of the cylinder head can be easily changed without greatly changing the structure of the conventional cylinder head. An in-cylinder injection spark ignition internal combustion engine with high combustion efficiency can be realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a direct injection gasoline engine according to the present invention.

FIG. 2 is a top view of the direct injection gasoline engine shown in FIG. 1 with a rocker cover removed.

FIG. 3 is a diagram illustrating the operation of the direct injection gasoline engine according to the present invention.

FIG. 4 is a diagram showing a time change of the outflow velocity V of the fuel particles injected from the fuel injection valve in relation to the tumble flow, and is a view for explaining the effect of the present invention.

[Explanation of symbols]

 Reference Signs List 1 engine (SOHC type direct injection gasoline engine) 4 cylinder head 10 cylinder 12 piston 16 cavity (recess) 20 combustion chamber 22 fuel injection valve 22a injection part (injection port) 44 intake port 46 exhaust port 50 intake valve 52 exhaust valve 90 ignition Plug (ignition plug) 90a Spark generator

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Koujiro Okada 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Tomo Yokoyama 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Automotive Industry Co., Ltd.

Claims (2)

[Claims] A piston inserted into a cylinder; a combustion chamber formed between an upper surface of the piston and a lower surface of a cylinder head; and a spark plug provided on the cylinder head so as to face the combustion chamber. A fuel injection valve provided in the cylinder head for directly injecting fuel into the combustion chamber; and an intake port formed in the cylinder head so that one end is open to the combustion chamber, for taking air into the combustion chamber. And a recess formed on an upper surface of the piston, for guiding intake air flowing into the combustion chamber from the intake port, and guiding fuel injected by the fuel injection valve to the vicinity of the spark plug. A valve is provided for the flow of intake air along and along the recess towards the spark plug at least when the piston is near top dead center during the compression stroke. An in-cylinder injection spark ignition type internal combustion engine characterized by injecting fuel so as to face the engine. 2. The ignition plug is disposed so as to face substantially the center of the combustion chamber, and the intake port has one end on one side of a plane including a cylinder axis along a central axis of the cylinder. The other end is opened to the combustion chamber and the other end is opened to a side surface of the cylinder head, and is formed so that intake air can flow into the combustion chamber toward the plane. The recess is disposed to face the combustion chamber at a position opposite to the plane with one end of the intake port interposed therebetween, and the recess is directed toward the plane at least when the piston is near top dead center during a compression stroke. The in-cylinder injection spark ignition type internal combustion engine according to claim 1, wherein the intake air thus introduced is guided toward the fuel injection valve.