KR950003737B1 - Stratified burning i.c. engine - Google Patents

Abstract

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Description

Layered Combustion Engine

1 is a schematic perspective view showing a layered combustion internal combustion engine as an embodiment of the present invention.

FIG. 2 is a schematic top view showing the main constitution of the intake port, and is a perspective view of FIG.

FIG. 3 is a schematic side view showing the main part structure of the combustion chamber, and is a perspective view of A 'in FIG.

4 is a schematic perspective view showing the piston top shape in detail.

FIG. 5 is a schematic partial cross-sectional view showing the structure of the intake port structure, and C-C cross-sectional view in FIG.

FIG. 6 is a schematic top view showing a configuration in a combustion chamber, and is a perspective A view in FIG.

FIG. 7 is a schematic diagram showing the configuration of an intake port structure, and A 'perspective view in FIG.

FIG. 8A is a schematic diagram showing the configuration of the intake port structure. FIG. 8A is a perspective view of FIG.

(B)-(g) are sectional drawing from S1-S1 cross section to S6-S6 cross section in FIG. 7, respectively.

FIG. 9 is a schematic diagram showing an intake port structure, taken along line B-B in FIG.

10 is a graph showing the effect of the intake port structure of the present invention.

11 is a graph showing the effect of the intake port structure of the present invention.

12 is a graph showing the effect of the intake port structure of the present invention.

13 is a graph showing the effect of the intake port structure of the present invention.

14 is a schematic perspective view showing the piston top shape in detail, and shows a modification of FIG.

FIG. 15 is a schematic perspective view showing the piston top shape in detail, and shows a modification of FIG.

16 is a graph showing the effect of the piston top shape of the present invention.

FIG. 17 is a schematic diagram showing the configuration of the intake port structure according to the present invention, showing a modification of FIG.

FIG. 18 is a schematic perspective view showing the configuration of a layered combustion internal combustion engine, and shows a modification of FIG.

FIG. 19 is a schematic partial sectional view showing the intake port structure of FIG. 18, showing a modification of FIG.

FIG. 20 is a schematic partial sectional view showing the intake port structure of FIG. 18, showing a modification of FIG.

FIG. 21 is a schematic partial sectional view showing the intake port structure of FIG. 18, showing a modification of FIG.

FIG. 22 is a schematic partial sectional view showing an intake port structure, and F-F sectional view of FIG.

FIG. 23 is a schematic perspective view showing the configuration of a layered combustion internal combustion engine, and shows a modification of FIG.

FIG. 24 is a schematic partial sectional view showing the structure of the intake port structure of FIG. 23, and an X-X sectional view of FIG.

FIG. 25 is a schematic partial cross-sectional view showing the structure of the intake port structure of FIG. 23, taken along the line V-V in FIG.

Fig. 26 is a schematic diagram showing the type of fuel injection in the intake port.

Fig. 27 is a schematic diagram showing a modification of the partition wall structure of the intake port structure of the present invention.

Fig. 28 is a schematic diagram showing a modification of the partition wall structure of the intake port structure of the present invention.

Fig. 29 is a schematic diagram showing a modification of the partition wall structure of the intake port structure of the present invention.

30 is a schematic diagram showing a modification of the partition wall structure of the intake port structure of the present invention.

FIG. 31 is a schematic diagram showing an intake passage structure of the present invention, showing a modification of FIG.

32 is a schematic diagram showing the intake passage structure of the present invention, and R1-R1 to R6-R6 cross section and G-G cross section of FIG.

FIG. 33 is a schematic diagram showing a modification of the intake passage structure of the present invention, and corresponds to FIG. 32 (c).

34 is a schematic perspective view of applying the present invention to another intake port structure having no partition wall.

35 is a schematic partial cross-sectional view and K-K cross-sectional view of the present invention applied to another intake port structure having no partition wall.

36 is a schematic top view of the present invention applied to another air intake port structure having no partition wall.

37 is a schematic perspective view showing a conventional layered combustion internal combustion engine.

38 is a schematic sectional view showing a conventional layered combustion internal combustion engine.

* Explanation of symbols for main parts of the drawings

11 spark plug 12 fuel supply means

21 partition wall 24 cylinder

26: piston 30: combustion chamber

34: piston top surface 35: recess

37: ridge 39: valve recess

46: intake air supply means 58: intake valve

60: cylinder head FC: virtual plane

L: Cylinder axis SF: Squishy

vf1, vf3, vf4: slope vf2: squishy part

The present invention relates in particular to a layered combustion internal combustion engine having a combustion chamber and an intake port structure suitable for layered combustion.

Background Art Conventionally, a layered combustion internal combustion engine has been known in which a dark mixture is formed in a combustion chamber for the purpose of low fuel consumption operation, and a ignition in the dark layer makes it possible to ignite a small air-fuel mixture as a whole.

As one of the laminar combustion internal combustion engines, for example, a laminar vertical vortex, ie, a laminar combustion internal combustion engine that generates tumble flow, as shown in Figs. It is already put to practical use.

37 and 38 show one cylinder structure of the two intake port type internal combustion engine. In the figure, reference numeral 322 denotes a cylinder block, 324 denotes a cylinder bore, 326 denotes a piston, 328 denotes a cylinder head, and 330 denotes a combustion chamber. 334 is an upper wall portion of the combustion chamber 330 and is formed in a pent roof shape having two slopes 330a and 330b. The intake ports 340 and 342 are respectively opened to the slope 330a of the combustion chamber 330, and the intake valves 358 are provided in both openings, respectively. Reference numeral 347 in the figure denotes an exhaust port communicating with the exhaust passage 360, and 359 denotes an exhaust valve.

The intake air flowing into the combustion chamber 330 from each of the intake ports 340 and 342 extends along the slope 330b of the cylinder bore 324 along the extension axis of the intake ports 340 and 342. It flows toward the inner wall surface, thereby producing a tumble such as indicated by arrows Fa and Fm in the combustion chamber 330, respectively.

38, the injector 312 is provided only in one intake port 342, and the spark plug 311 intakes the intake port part 342 equipped with this injector 312. As shown in FIG. It is disposed near the valve 358. For this reason, in the vicinity of the spark plug 311, the tumble flow Fm of the mixer by the fuel injected from the injector 312 and the intake | exhausted air is formed, and thereby the tumble flow Fm of the mixer and the air in the combustion chamber 330 are formed. The tumble flow of fa is a layered tumble flow is formed.

Therefore, since the air / fuel ratio of air and fuel in the combustion chamber 330 is large, that is, the combustion chamber 330 as a whole has a darker mixture than other parts around the spark plug 311 even when the fuel concentration is light and lean. A stable combustion state can be obtained.

However, by performing the layering in the combustion chamber more completely, lean burn with a higher air-fuel ratio becomes possible, and by making the tumble flow stronger, it becomes possible to perform the layering more completely.

An object of the present invention is to provide a layered combustion internal combustion engine that generates a stronger tumble flow in the same combustion chamber in order to perform the layering of the combustion chamber more completely, thereby enabling lean combustion with higher air-fuel ratio. It is. Also, in this type of combustion combustion internal combustion engine, minute disturbance is generated in the layered tumble flow immediately before the ignition timing, thereby increasing the combustion speed after ignition, thereby improving combustion efficiency and reducing HC. It is an object to provide a layered combustion internal combustion engine.

To this end, the vertical whirl-bed combustion internal combustion engine of the present invention is configured as an apparatus including the following features.

① It is disposed on one side of the virtual plane including the combustion chamber defined by the upper surface of the piston and the lower cylinder head which are inserted into the same cylinder as the inner surface of the cylinder, the spark plug provided on the inner surface of the combustion chamber, and the cylinder axis on the lower surface of the cylinder head. And a plurality of intake openings each opened and closed by an intake valve, the intake air being spaced along the cylinder head lower surface from the intake opening so as to generate a tumble flow parallel to each other and substantially in the same direction in the combustion chamber. Supplying fuel to intake supply means for introducing intake air from one side of the virtual plane to the other, and intake air generating a tumble flow at a position corresponding to the ignition plug in the intake supply means; Fuel holes that present a layered tumble flow in the combustion chamber To a means and promote the tumble flow of the layer-is characterized in that with at least one surface is the top surface of the piston along the flow direction of the tumble flow.

(2) The said inclined surface of said (1) is characterized in that it is formed in the said piston top surface, and is set by the slope of the said virtual plane side of the ridge part which has the top in at least one of the said virtual plane.

(3) The said piston top surface is provided with the recessed part adjacent to the said gas phase plane side of the said raised part, The said recessed part is characterized by having the surface smoothly continuous with the said sloped surface of the said raised part.

(4) The squishy part according to the above (1), which generates a squish in cooperation with the ceiling of the combustion chamber near the compression stroke top dead center of the piston, at a portion farther from the imaginary plane than the upper end surface of the top surface of the piston. It is characterized by having.

(5) In the above (2), the ridge has a top only on one side of the virtual plane.

(6) The above-mentioned (2) is characterized in that the ridge has its top only on the other side of the virtual plane.

(7) The ridge portion (2) is characterized in that the ridge has its top on each of the one side and the other side of the virtual plane.

(8) The cross section between the plane parallel to the virtual plane and the slope is characterized in that the straight line is substantially straight line.

(9) The valve recess is provided at a part farther from the imaginary plane than the upper end of the slope at the ridge to avoid interference between the piston top surface and the intake valve for opening and closing the intake opening. Characterize

(9) In the above (9), the portion farther from the imaginary plane than the slope at the ridge portion generates squish in cooperation with the ceiling of the combustion chamber near the compression stroke top dead center of the piston.

사 characterized in that the slope is formed by the surface of the recess formed on the top of the piston.

(2) one side of the imaginary plane including the combustion chamber defined by the inner surface of the cylinder and the upper surface of the piston and the lower cylinder head inserted in the cylinder, the spark plug provided on the inner surface of the combustion chamber, and the cylinder axis on the lower surface of the cylinder head. It has two intake flow openings which are opened and closed by two intake valves, and along the cylinder head lower surface from the intake opening so as to generate a tumble flow which is parallel to each other in the whole of the combustion chamber and in the same direction by intake air. An intake port for introducing intake air from the one side of the imaginary plane to the other, a plurality of intake ports formed extending from the upper inner surface of the intake port toward the lower inner surface, and partitioning the intake port into a plurality and paralleling the tumble flows with each other; At least one partition wall partitioned by flow of gas and the ceiling center of the combustion chamber Fueling for generating a tumble flow at the positions corresponding to the discharged spark plug inlet, thereby characterized in that it includes a fuel supply means for the presence of the tumble flow of the layer-in the combustion chamber in the intake process.

(3) The said slope is formed by the slope of the said virtual plane side of the ridge part provided in the said piston top surface, and having the top in at least one of the said virtual plane.

(3) The said piston top surface is provided with the recessed part adjacent to the said virtual plane side of the said raised part, The said recessed part is characterized by having the surface which is smoothly continuous with the said slope of the said raised part.

(B) having a squishy portion in cooperation with the ceiling of the combustion chamber in the vicinity of the compression stroke top dead center of the piston at a portion farther from the imaginary plane than the upper slope on the top surface of the piston It features.

The cross section between the plane parallel to the virtual plane and the slope is characterized in that the straight line is substantially straight.

A valve recess is provided in a part farther from the imaginary plane than the upper end of the slope in the ridge to avoid interference between the piston top surface and the intake valve for opening and closing the intake opening. do.

The said distant part from the said imaginary plane rather than the said slope in the said ridge part produces squish in cooperation with the ceiling of the said combustion chamber near the compression stroke top dead center of the said piston.

The said slope is formed by the surface of the recessed part formed in the said piston top surface.

It is disposed on one side of the imaginary plane including the combustion chamber defined by the inner surface of the cylinder and the upper and lower cylinder heads inserted into the cylinder, the ignition plug provided on the inner surface of the combustion chamber, and the cylinder axis on the lower surface of the cylinder head. Each of the plurality of intake openings opened and closed by the intake valves, the intake air being substantially parallel to each other in the combustion chamber and generating a tumble flow in the same direction and along the cylinder head lower surface from the intake opening; An intake port for introducing intake air from the one side of the plane to the other and an intake port for generating a tumble flow at a position corresponding to the spark plug disposed on the ceiling of the combustion chamber, thereby supplying fuel to the combustion in the intake stroke It is equipped with a fuel supply means which makes a floor tumble flow exist indoors. And that is characterized.

remind The said slope is formed by the slope of the said virtual plane side of the ridge part which is provided in the said piston top surface, and has the top in at least one of the said virtual plane.

remind The said piston top surface is provided with the recessed part adjacent to the said virtual plane side of the said raised part, The said recessed part is characterized by having the surface smoothly continuous with the said inclined surface of the said raised part.

remind The squish portion which generates squish in cooperation with the ceiling of the said combustion chamber near the compression stroke top dead center of the said piston in the part which is far from the said virtual plane rather than the said slope equivalent part in the said piston top surface. It is done.

remind The intersection line between the plane parallel to the virtual plane and the slope is characterized in that it is substantially straight.

remind The valve recess is provided in a portion farther from the imaginary plane than the upper end of the slope in the ridge to avoid interference between the piston top surface and the intake valve for opening and closing the intake opening. .

remind The said distant part from the said virtual plane rather than the said slope in the said ridge part produces squish in cooperation with the ceiling of the said combustion chamber near the compression stroke top dead center of the said piston.

remind The said inclined surface is formed by the surface of the recessed part formed in the said piston top surface.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

A first embodiment of the present invention will be described with reference to FIGS.

First, the schematic configuration of the layered combustion internal combustion engine of the first embodiment will be described using FIG. In each cylinder of the internal combustion engine, the combustion chamber 30 is formed by the cylinder bore 24 formed in the cylinder block 22, the piston 26, and the cylinder head 28.

The intake port 46 communicates with the combustion chamber 30. Specifically, the intake port 46 is divided into two portions by the branch portion 46C, and the intake port 46 has two intake ports 46A and 46B respectively opened in the combustion chamber 30. It is. Intake valves 58 for opening and closing the intake openings are arranged at the intake openings of the intake ports 46A and 46B to the combustion chamber 30, respectively. Moreover, the exhaust port 47 to the combustion chamber 30 is connected. In detail, the exhaust port 47 is a size port having two exhaust ports 47A and 47B, which are two minutes in the middle and open in the combustion chamber 30, respectively. Exhaust valves (not shown) are disposed in the openings of each exhaust port to the combustion chamber 30, respectively. In addition, each of the intake ports 46A and 46B is opened in the combustion chamber 30 on one side of the virtual plane FC including the cylinder axis L, and each of the exhaust ports 47A and 47B is different from the virtual plane FC. Is opened in the combustion chamber 30 from the side. The ceiling of the combustion chamber 30, which is determined by the lower surface 60 of the cylinder head 28, is formed in a pen loop shape having two slopes 60a and 60b so as to have a top on the virtual plane FC. have. In the center of the ceiling of the combustion chamber 30, an ignition plug 11 as an ignition means is provided.

In the upstream portion of the branch 46C in the intake port 46, an injector 12 as fuel injection means described in detail later is mounted. The fuel is injected by the injector 12 from the vicinity of the branch portion 46C of the intake port 46 toward the downstream side.

As shown in FIG. 1 and FIG. 2, the axial center lines 1A, 1B of each intake port 46A, 46B become a straight line parallel to each other. In other words, each of the intake ports 46A and 46B has a straight directional determination portion parallel to each other. The intake air from each of the intake ports 46A and 46B flows into the combustion chamber 30 in a state parallel to each other.

The intake air introduced into the combustion chamber from each of the intake ports 46A and 46B in the intake stroke is formed along the slope 60b of the lower surface 60 of the cylinder head 28 forming the ceiling of the combustion chamber. The intake air flows to the other side, and the intake air descends along the inner surface of the cylinder bore 24 and flows to the piston upper surface 35, and the intake air rises along the inner surface of the cylinder bore 24, whereby the cylinder head 28 Flows to the slope 60a of the lower surface 60, whereby the combustion chamber 30 generates vertical swirls (tumble flow) almost entirely.

In each of the intake ports 46A and 46B, partition walls 21 extending in the longitudinal direction are substantially formed along the axis lines 1A and 1B, respectively. Each partition wall 21 divides each intake port 46A and 46B into the central passage 4 and the outer side passage 5. The injector 12 is configured to inject fuel toward the central passage 4 which generates a tumble flow at a position corresponding to the spark plug 11.

By the above structure, in the intake stroke, the tumble flow Fm containing fuel and the tumble flow Fa containing no fuel are produced | generated in the combustion chamber 30 in layer form. It is also important that the tumble flows Fm and Fa are substantially parallel to each other and in the same direction, whereby the layered tumble flows Fm and Fa may exist in the combustion chamber 30 even in the compression stroke.

In addition, in this embodiment, each structure has a characteristic, respectively, and it demonstrates in order below.

First, the top face shape of the piston 26 is demonstrated. The piston 26 is provided with the raised part 37 in each top surface 34, as shown to FIG. 1, FIG. 3, and FIG. The top of the ridge 37 is located on the intake opening side of the intake port 46 of the virtual plane FC on the top surface 34. The slope vf1 on the imaginary plane FC side of the raised portion 37 is configured to smoothly continue to the top surface 34 of the piston 26. Moreover, the slope vf1 of the ridge 37 is comprised so that the cross section parallel to the virtual plane FC may become a straight line parallel to the reference surface of the top surface 34 of the piston 26. That is, the slope vf1 of the ridge 37 is mixed with each other when the tumble flow Fm, Fa changes from the top surface 34 of the piston 26 toward the inner surface of the cylinder bore 24 in the intake stroke. It is comprised so that the layer formation may be kept clean.

Moreover, when the piston 26 is near the top dead center of the compression stroke, the outer slope vf2 of the ridge 37 generates squishy SF in cooperation with the ceiling of the combustion chamber 30, thereby causing the tumble flow Fm, Fa. It is configured so that minute disturbances occur.

Moreover, as shown in FIG. 1, FIG. 3, and FIG. 4, the valve reset 39 which prevents interference with the intake valve 57 is provided in the outer slope vf2 of the ridge 37. As shown in FIG. . Thereby, even if the intake valve 57 opens the valve at the overlapping point at the top dead center, the piston 26 can maintain the top dead center position with a high compression ratio without interfering with the intake valve 57.

In addition, in FIG. 3, illustration of the partition wall 21 is abbreviate | omitted for convenience of description.

Next, the partition wall 21 provided in the above-mentioned intake ports 46A and 46B will be described. As shown in FIG. 5, each partition wall 21 has a downstream end portion 21b of the intake ports 46A and 46B extending near the intake valve 58. As shown in FIG. In detail, the downstream end portion 21b of each partition wall 21 is provided in the valve head portion 56 of the intake valve 58 or in the stem portion 57 that crosses the intake ports 46A and 46B. It is secured and formed with these reasons so as not to contact. For this reason, it is formed so that there is no influence on the operation | movement of the intake valve 58. FIG. Moreover, each partition wall 21 is the center line 45A of each flow line 45 of each intake port 46A, 46B, and the axial center line 1A, 1B of the intake port parts 46A, 46B. It is formed along. As a result, the intake air flowing into the intake port 46 flows into the combustion chamber 30 in a more rectified state. Here, since the intake port portions 46A and 46B are substantially parallel to each other, these partition walls 21 and 21 are also disposed substantially parallel to each other. 2 and 6, the upstream end portion 21A and the downstream end portion 21B of the partition wall 21 are formed in a convex curved surface so that the rectifying effect of the mode intake air flow is improved. The formation of the upstream side 21A and the downstream end portion 21B in this manner is aimed at the effect of reducing the flow resistance by rectifying the intake air flow, and at the same time, considering the manufacturing effect of the partition wall 21. That is, when the partition wall end portions 21A and 21B are formed in a convex curved surface, for example, when the intake port 46 is cast, the mold corresponding to the partition wall end portions 21A and 21B ( The core) can be easily removed, and casting can be performed reliably and easily.

Next, the arrangement of the injector 12 and the relationship between the injector 12 and the partition wall 21 will be described with reference to FIGS. 1, 3, 5, and 6.

As shown in FIG. 6, the partition wall 21 separates each of the intake ports 46A and 46B into a central passage 4 and a lateral passage 5. As shown in FIG. 1, FIG. 3, and FIG. 6, the injector 12 as fuel injection means is arrange | positioned upstream of the branch part 46C in the two intake ports 46. As shown in FIG. In addition, this injector 12 is adapted to inject fuel into two intake ports 46A and 46B downstream in accordance with the intake stroke. Reference numeral 6 in Figs. 5 and 6 denotes the axis of the injector and indicates the center line of the injection range.

That is, as shown in the injection axis | shaft 6 of FIG. 5, FIG. 6, the fuel injected from the upper surface part of the intake port is made to intake in the combustion chamber 30 through the center passage 4, and a side passage Only air is sucked into the combustion chamber 30 from (5).

As a result, the flow branched into the central passage 4 and the lateral passage 5 in the intake ports 46A and 46B is rectified by the partition wall 21 while maintaining the separated state from each other. It is supposed to flow in the form of layers inside. Therefore, by the partition wall 21, when the flow of intake air flows into the combustion chamber 30 as shown in FIG. 6, only Fm and air, which are Fm and air, which follow a mixer in which fuel is mixed with air, The tumble flow of the state which isolate | separated into three layers (a total of three flows of the central passage 4 and the both side passages 5), ie, the layered state, is formed.

Next, the thickness of the valve stem 57 and the thickness of the partition wall 21 will be described with reference to FIGS. 2 and 6.

As shown in FIGS. 2 and 6, the center line of the partition wall 21 and the center line of the valve stem 57 are located on the same plane, and the thickness of the partition wall 21 is the diameter of the valve stem 57. It is formed thinner. In other words, the surface 21a of the partition wall 21 toward the center passage 4 has a shape that is more biased toward the side passage 5 than the surface of the valve stem 57 toward the center passage 4.

As a result, as shown in FIG. 6, the fuel spray in the mixed air stream along the inner surface 21a of the partition wall 21 is guided to the inner surface of the valve stem, and along the arrow P shown in FIG. 11), this fuel spray is concentrated on the spark plug (11).

Next, the cross-sectional shape of the intake port 46 in the intake air flow direction will be described with reference to FIGS. 7 and 8.

FIG. 7 is a cross-sectional view of the intake port 46 in the intake air flow direction, and FIG. 8 is a view showing cross-sectional shapes S1-S1 to S6-S6, respectively, in cross sections orthogonal thereto. As shown in FIGS. 8 (a) to 8 (g), the intake port 46 has the upper half 46A-1 and the lower half 46A- as the upper half 46A-1 faces the downstream side. 2), It is relatively wider than 46B-2, and is formed. As a result, the intake air flow from the intake ports 46A and 46B easily forms a tumble flow in the combustion chamber 30. The intake ports 46 branch to the size pots at the cross section S3-S3 in FIG. 8 (f) to form intake ports 46A and 46B. The port shape also shows the shape of an inverted triangle. In addition, the intake ports 46A and 46B show a cross-sectional shape of an inverted triangle toward the downstream side, whereby the tumble flow is enhanced.

That is, by expanding the upper half portion 46-1 in each cross section of the intake port 46 wider than the lower half portion 46-2, the upper half portion 46-1 is placed on the intake port 46. Flow rate and flow rate are larger than the lower half. On the other hand, when the intake valve 58 is opened, there is a component a of the flow that increases the tumble flows Fa and Fm and a component b of the flow that suppresses the tumble flows Fa and Fm, as shown in FIG. . Therefore, the flow rate and the flow rate of the upper half of the intake port 46 become larger than the lower half, so that the tumble flows Fa and Fm can be made stronger. In addition, the component a of the flow is the same as the direction of the tumble flows Fa and Fm, so the flow resistance to the component a of the flow is very small, so that the flow rate as a whole can be greatly increased.

In addition, as shown in Figs. 8A to 8G, partition walls 21 are provided in the intake port 46 over almost the entire length. The partition wall 21 is provided from the intake port lower wall surface 7 to the intake port side wall surface 8 so as to divide the inside of the intake port portions 46A and 46B in two directions. It can be seen that the flow of intake air flows into the central passage 4 and the side passage 15 from the intake air flowing into the intake port portions 46A and 46B.

That is, as shown in Fig. 8A, two intake port portions 46A and 46B are formed as one intake passage near the cylinder head side 28A (Fig. 7) on the uppermost side. Immediately after this, the partition wall 21 branches the flow of intake air into the side passage 5 of the central passage 4. As shown in Figs. 8B and 8D, the central passage 4 is gradually divided into two minutes, and downstream of the cross section S4-S4 shown in Fig. 8E, the intake air is completely reduced. Minutes. The intake air flow divided in this manner flows into the combustion chamber 30 by the intake valve 58, respectively.

The intake port 46 will be described in more detail with reference to FIGS. 7, 8, and 9.

As shown in FIG. 7, the intake port 46 is oriented to the intake air flow to generate a tumble flow in the combustion chamber 30. Thus, the intake port 46 has a substantially straight shape. On the other hand, due to the structure of the cylinder head, the direction of the axis of the intake openings opened and closed by the intake valve 58 and the intake air flow cannot be the same. For this reason, the downstream ends of the intake ports 46A and 46B are connected to the intake opening through a curved portion having a large curvature. The actual flow cross-sectional area at this curved portion is the smallest as is apparent in FIGS. 8 (f) and 8 (g), in particular with the presence of the valve stem 57, not shown stem guide and partition wall 21, The real distribution area is severely reduced.

For this reason, the width | variety of the inner diameter of this curved part in the intake port 46A, 46B, the copper intake port 46A, 46B is the largest, and the intake opening through which each intake valve 58 is interposed. A bulging portion 13 set larger than this is formed. As a result, it is possible to prevent a decrease in the actual flow cross-sectional area at the curved portion and to secure a sufficient flow rate and flow rate.

In addition, since the convex part 13 is mainly formed in the upper half part 46A-1, 46B-1 of each intake port 46A, 46B, as shown in FIG. The flow rates and flow rates of the 46A-1) and 46B-1 can be made larger than the lower half portions 46A-2 and 46B-2, and the tumble flows Fa and Fm are more effectively generated.

Since the layered combustion internal combustion engine according to the first embodiment of the present invention is configured as described above, the intake air flowing into the combustion chamber 30 from each of the intake ports 46A and 46B in the suction stroke is the combustion chamber 30. ), The tumble flow Fm of the mixer and the tumble flow Fa of air are generated in the form of layers. Subsequently, even when entering the compression stroke, the layered tumble flows Fm and Fa exist, but as they near the compression stroke top dead center, each tumble flow Fm and Fa starts to collapse. However, in the vicinity of the spark plug 11 in the combustion chamber 30, a dark mixer still exists, and in this state, ignition is performed by the spark plug 11. The subsequent explosive stroke and exhaust stroke are exactly the same as the internal combustion engine of a conventional layered combustion internal combustion engine.

As a result, as the entire combustion chamber 30 is a mixer having less fuel than the theoretical fuel ratio, a mixer having a concentration sufficient for ignition exists near the ignition plug 11, so that the engine can be operated without degrading ignition.

In particular, in the present embodiment, the concave portion 35 and the ridge portion 37 are formed on the top surface 34 of the piston 26 to generate stronger tumble flows Fm and Fa, thereby creating a more complete layered tumble. The flows Fm and Fa can be obtained. Thereby, ignition and combustion sufficiently stable can be obtained even if the air-fuel ratio of the entire mixer in the combustion chamber 30 is made smaller.

In addition, the external slope vf 2 of the ridge 37 of the piston 26 causes fine disturbance to the mixer by Squishy SF generated near the top dead center of the compression stroke in cooperation with the ceiling of the combustion chamber 30. Since it produces | generates, the combustion speed after ignition is improved. In addition, since this squishy SF has an adverse effect when it is too strong, it is important to make the space | interval of the outer slope vf2 and the ceiling of the combustion chamber 30 at the time of piston top dead center adjusted suitably. Moreover, when the valve reset 39 is provided in the outer slope vf2 of the ridge 37, and the piston 26 reaches top dead center, even if the intake valve 57 is opened by the valve overlap, it is the outer side. It is comprised so that interference of the slope vf2 and the intake valve 57 may be avoided. For this reason, the top dead center of the piston 26 can be made higher, a compression ratio can be raised, and combustion efficiency can be improved.

That is, as shown in the graph of FIG. 10, the partition wall 21 is provided in the intake ports 46A and 46B to promote the layering of the mixer, so that the engine can be operated by a thinner mixer. The horizontal axis of the figure is the air-fuel ratio (A / F), and an ordinate is the NO _X emissions and Pi (indicated mean effective pressure) fluctuation rate. Lines a and c show the characteristics of the engine provided with the partition wall 21 on the intake port, and lines b and d have an intake port for a normal tumble flow without the partition wall 21. Indicate the characteristics of an institution. Lines a and b are for NO _x emissions, and lines c and d are for Pi variability.

As shown in FIG. 10, in the engine provided with the partition wall 21 (see line a), the value of A / F is thinner than the engine (see line b) using a normal tumble flow. NO _x emissions peak. In addition, it is possible to also reduce the peak value itself of the NO _X emissions. That is, because the tumble flow in the combustion chamber 30 is accelerated in layering, the A / F in which the NO _x emission peaks compared to the conventional engine moves toward the lean side.

In addition, the lines c and d show the relationship between the A / F and Pi variability. Here, the Pi fluctuation rate is used as a criterion for judging combustion stability of the engine. If the Pi fluctuation rate is too high, combustion of the engine is not stabilized and an unpleasant operation state accompanied by torque fluctuation is achieved. In addition, the reference line e in the figure is generally the Pi variation rate of the combustion stability limit that can be operated in the absence of discomfort.

As shown in this figure, in the engine (see line C) provided with the partition wall 21 with respect to the limit of Pi variation rate at which a stable combustion state is obtained in the cylinder, the engine using a normal tumble flow (see line) In addition, the engine can be operated at a lean A / F, and the amount of NO _x emitted at this time can be greatly reduced. That is, it shows that stable combustion state can be obtained even in thinner A / F, and the A / F of a combustion system can be improved.

Therefore, this structure can realize an engine that is very low fuel consumption and emits little NO _x .

Moreover, since the thickness of the partition wall 21 is smaller than the diameter of the valve stem 47, and the center line of the partition wall 21 and the center line of the valve stem 57 are located on the same plane, the partition wall 21 The central notification side wall is biased toward the side passage 5 than the central passage side wall of the valve stem 57, and the fuel spray in the mixed air stream along the partition wall 21 in the central passage 4 is connected to the valve stem 57. Guided to the inner surface of the c), it is directed in the direction of the spark plug 11, and the fuel spray in the mixer is concentrated near the spark plug 11, so that the ignition is performed well, and the lean limit can be further extended.

In particular, in the present embodiment, as shown in Figs. 7 and 9, in the present structure, the upper half portions 46A-1, (the upper half of the cross section of the substantially inverted triangle of the intake ports 46A and 46B) ( Since 46B-1) is large enough, the strong tumble flow in the combustion chamber 30 and the flow rate coefficient at the time of full engine opening can be ensured.

In the present embodiment, the bulging portions 13 are formed at the curved portions where the most effective flow cross-sectional areas of the intake ports 46A and 46B are small, and the flow resistance is downstream of the valve stem 57. Since the partition wall 21 to be provided is not provided, the strong tumble flow in the combustion chamber 30 and the flow coefficient at the time of full engine opening can be ensured more effectively.

Moreover, the structure which does not provide the partition wall 21 downstream of the valve stem 57 in the intake ports 46A and 46B has a big advantage in manufacturing method as demonstrated below. That is, if the partition wall 21 is provided downstream of the valve stem 57, it is necessary to drill the part corresponding to the valve stem 57 in the partition wall after casting of the partition wall, Due to its thinness, there is a risk of cracking during drilling, and there is a partition wall on one support downstream of the valve stem 57 in the intake ports 46A and 46B, which is undesirable in terms of strength. This occurs. However, in the present embodiment, since the partition wall 21 does not exist on the downstream side of the valve stem 57 as described above, inconveniences such as the outside can be avoided at all. It is also confirmed that there is almost no effect on the layering even if the partition wall 21 downstream of the valve stem 57 is not provided, which can provide a great advantage in manufacturing.

Here, FIG. 11 shows the relationship between the port area and the average tumble ratio (rotational speed of the tumble flow / engine rotational speed) and the average flow coefficient (flow rate as a whole). Here, line a indicates the relationship between the port area and the average tumble ratio, and line b indicates the relationship between the port area and the average flow coefficient, and the mark indicates the cross section of the intake ports 46A and 46B. The average flow coefficient of the engine provided with the intake port with the upper half portion 46A-1 and 46B-1 large enough to be displayed.

Indicates the average tumble ratio of the engine provided with the intake port of the normal tumble flow, and indicates the upper half portions 46A-1 and 46B- in the intake ports 46A and 46B. Since 1) is sufficiently enlarged to secure the port cross-sectional area, as shown in the figure, both the average tumble ratio and the average flow coefficient can be improved.

As a result, the relationship between the tumble ratio and the flow rate coefficient is as shown in FIG. In FIG. 12,? Indicates an engine using a conventional tumble flow, and ☆ indicates a partition wall 21. However, the partition wall 21 provides a cross-sectional area within the intake port portions 46A and 46B. This declining engine, the symbol (*), is an engine having the present structure, in which the upper half portions 46A-1 and 46B-1 of the cross sections of the intake ports 46A and 46B are sufficiently large. That is, as shown in FIG. 12, only by providing the partition walls 21 in the intake ports 46A and 46B, the flow coefficient decreases even when promoting the layering of the intake air, resulting in a complete opening performance. It is inconvenient to lower. Here, as indicated by ★, the tumble ratio and the flow rate coefficient can be improved by sufficiently increasing the upper half portions 46A-1 and 46B-1 of the cross-sectional areas of the intake ports 46A and 46B. In this way, it is possible to compensate for the reduction in the cross-sectional area of the intake ports 46A and 46B by providing the partition wall 21, and to secure the strong tumble flow in the combustion chamber 30 and the full opening performance of the engine. It can be.

Fig. 13 shows the rotational torque and output of the engine, in which the lines a and c show the characteristics of the engine having the present structure, and the lines b and d show the conventional intake port structure. It is a graph which shows the characteristic of the equipped engine. First, the lines a and b show the relationship between the rotational speed of the engine and the torque. However, these two curves are hardly different from each other. It shows that it is realized.

The lines c and d show the relationship between the rotational speed of the engine and the output. However, the lines c and d are similar to the torque characteristics described above. Indicates that the engine and output can be obtained.

Therefore, as shown in FIG. 13, the engine having this structure can realize an internal combustion engine with torque and output characteristics equivalent to those of the conventional engine, as a result of the increase in the tumble ratio and the flow rate coefficient of the intake ports 46A and 46B. Can be.

Thus, the partition wall 21 is provided in the intake port 46, and sufficient upper half 46A-1 and 46B-1 of the substantially triangular cross section of the intake port 46A and 46B is sufficient. by large torque and output at the same time in both a stable combustion state by one lean mixture than a conventional internal combustion engine, without reducing all of the conventional internal combustion engine it can be reduced also nO _X. At the same time, fuel economy can be improved.

Next, the modified example regarding the shape of the piston upper surface is demonstrated using FIG. 14 and FIG.

The engine of FIGS. 1 and 3 of the first embodiment had a piston 26 having recesses 35 and ridges 37 as shown in FIGS. 4A and 4B. Instead, the piston 26a as shown in Figs. 14A and 14B is employed.

The piston 26a of FIGS. 14A and 14B has a recess 35 and a ridge 37a on its upper surface. The top of the ridge 37a is located on the intake opening side of the intake port 46 of the virtual plane FC on the top surface 34. The slope vf3 on the imaginary plane FC side of the raised portion 37a is configured to smoothly continue to the upper surface of the piston 26a. The slope vf3 is a shape which is perpendicular to the virtual plane FC and symmetrical with respect to the plane including the cylinder axis.

In the modifications of Figs. 14A and 14B, since the slope vf3 is concave as described above, the tumble flows Fa and Fm are oriented so as to follow the cylinder bore inner wall surface from the upper surface of the piston 26a. When changing, move them all to the center of the tumble flow Fm. However, since the slope vf3 is symmetrical as described above, the layered state of the tumble flows Fa and Fm does not collapse.

The following modified example employs the piston 26b as shown in Figs. 15A and 15B.

Piston 26b of FIG. 15 (a), (b) has the recessed part 36 and the raised part 37b in the upper surface. The top of the double raised portion 37b is located on the intake opening side of the intake port 46 of the virtual plane FC on the top surface 34. On the other hand, the recessed part 36 is located adjacent to the virtual plane FC in the top surface 34. As shown in FIG. The slope vf4 on the virtual plane FC side of the raised portion 37b is configured such that the upper surface of the concave portion 35 has a straight line parallel to the reference upper surface of the piston 26b.

In the modifications of Figs. 15A and 15B, since the concave portion 35 is formed together with the ridge portion 37b, the tumble flows Fa and Fm are applied to the piston 26b from the inner wall of the cylinder bore. When changing the direction along the top surface, the layered state of the tumble flows Fa and Fm is kept cleaner.

Here, in FIG. 16, the characteristic of the engine in which the conventional piston upper surface is parallel is N line, the characteristic of the engine E of the piston upper surface which has the inner wall vf1 of FIG. 1 is A line, and the recessed part 35 of FIG. And the characteristic of the engine of the piston upper surface which has the inside wall vf4 is shown by the C line. In this case it was shown in turn to the combustion stability and, output shown as, NO _X Reduction rate. In this test, the air-fuel ratio is changed by changing the amount of air with a constant amount of fuel. In this case, the difference in the city output indicates the difference in fuel economy.

The lean marginal fuel ratio improved from type A to 1 and type C to 2 as compared to the standard type. As a result, NO _X is reduced in the lean revealed in 50% of type A, type C and 16%.

Next, a modification of the partition wall 21 in the intake ports 46A and 46B will be described using FIG. 17. In this modification, instead of the partition wall 21, the partition wall 21Q is provided only in the substantially lower half of the intake ports 46A and 46B. However, as described above, the injector 12 is disposed upstream from the branch portion 46C of the intake port 46 from the intake port upper surface downward. Since the fuel tends to collect on the lower side of the intake port, the tumble flow Fa and Fm by the central passage 4 and the side passage 5 can be obtained even when the fuel is installed only on the relatively lower side of the intake port like the partition wall 12Q. Layering is sufficiently possible.

Next, a modification of the relationship between the arrangement and the direction of the injector 12 and the partition wall 21 will be described using FIGS. 18 to 25.

As shown in the axial direction 6 of the injector 12 of FIG. 18 and FIG. 19, the injector 12 is downstream from these intake ports 46A and 46B from the lower side of the intake port 46. As shown in FIG. Inject fuel at an angle upwards. The fuel injected obliquely upward is intaken into the combustion chamber 30 through the central passage 4 in the intake ports 46 and the intake ports 46A and 46B.

In FIG. 20, instead of the partition wall 21 in FIG. 19, the partition wall 21 is arranged from the upper side of the intake port, and the partition wall 21C is provided only in the upper half. According to these modified examples shown in FIGS. 19 and 20, fuel is injected along the injector injection axis 6 toward the upper inner wall 8 and the tumble flow of the mixer formed near the spark plug 11. In Fm, the flow side of the tumble flow center outside the spark plug 11 is thicker than the flow inside the tumble flow center of this tumble flow Fm. Therefore, lean burn can be more stably established.

As shown in FIG. 21 and FIG. 22, the partition wall 21 is provided in the upper half of the intake port 46, the intake port 46A, 46B. Only this upper half is to be divided into two minutes from side to side. In addition, along the lower edge of the partition wall 21C, an approximately horizontal partition wall 21F as an auxiliary wall is formed so that the air intake port 46, the air intake ports 46A, and 46B are divided up and down. It is installed. Therefore, the partition walls 21F allow the upper half portions 46A-1, 46B-1 and the lower half portions 46-2, 46A-2 and 46B to enter the intake ports 46A and 46B. -2) partitions. In addition, the upper half 46A-1 and 46B-1 are divided into 21 minutes by the partition wall into the center side (ignition plug side) passage | route and the side (ignition plug opposite side) passage 5 for 2 minutes. And the injector 12 is comprised so that fuel may be inject | poured into the upper part rather than the partition wall 21F in the center passage 4 of each intake port 46A, 46B. As a result, the outside of the tumble flow Fm of the mixer becomes a mixer having a high fuel concentration, which concentrates near the spark plug 11. This enables a stable combustion state even with a lean fuel.

23 to 25 are provided with auxiliary partition walls 21G in place of the auxiliary partition walls 21F shown in FIGS. 21 and 22. However, the injector 12 is disposed on the upper surface of the intake port 46 and also upstream of the branch portion 46C as in the first embodiment. The upstream end of the partition wall 21G is provided up to the position of the injector 12 in the vicinity of the partition wall 21C in the vertical direction. The horizontal partition wall 21 prevents the fuel injected from the inlet 12 from diffusing downward in the intake port 46. That is, in the upstream side of the branch part 46C of the intake port 46, the center passage 4 of the longitudinal cross section like FIG. 24 is formed in the upper part in the intake port 46, for example. That is, the inside of the intake port 46 becomes two minutes to the side passage 5 of the center passage 4. Further, downstream from the branching portion 46C, the central passage 4 is formed above the reference plane 3 in each of the intake ports 46A and 46B. As a result, the fuel injected toward the lower side of the intake ports 46A and 46B is prevented from entering the side passage 5 by the horizontal partition wall 21G provided in the intake ports 46A and 46B. . The injected fuel flows into the central passage 4 of the upper half portions 46A-1 and 46B-1, and only air flows into the side passage 5. In addition, since the partition wall 21G extends from the upstream side to the downstream side from the excretion position of the injector 12, the fuel is reliably placed in the upper half portions 46A-1 and 46B-1 of the intake ports 46A and 46B. Can flow into the central passage 4, so that the outside of the tumble flow Fm of the mixer becomes a high fuel concentration mixer, which concentrates near the spark plug 11. As a result, the mixer can reliably ignite and combust in the combustion chamber 30, thereby enabling a stable combustion state even with a lean fuel than before.

Next, a modification of the injection of the injector 12 will be described using Figs. 26A to 26D.

(a) is to inject fuel toward the branch portion 46C of the size-type intake port 46. After actively impinging the fuel on the branch portion 46C, the diffused fuel is injected into the intake port 46A. Into the central passage 4 in the 46B). The branch portion 46C of the intake port 46 has an aggressive collision surface that is substantially orthogonal to the injection direction of the injector 12, and diffuses the fuel collided with the collision surface.

(b) is a type in which the injector 12 provided with two fuel injection holes is used, and the flow of two fuel injected from each fuel injection hole is respectively centered in the intake port 46A and 46B. Enter the passage directly. In this case, the branched portion 46C of the intake port 46 is formed in a curved shape to reduce the intake resistance of the intake air streams.

(c) is a type of injecting fuel directly into the central passage 4 so that the fuel injection hole uses one injector 12 so that no fuel adheres to the partition walls 21 and 21. . In this case, the branch portion 46C of the intake port 46 is formed at an acute angle so that the fuel can be sucked smoothly with the intake air.

Contrary to the above (c), (d) is a type of actively injecting fuel over the partition walls 21 and 21 toward the wide angle. In this case, the branch 46C of the intake port 46 is rounded in the same curved shape as in the above (b) in order to reduce the resistance.

In addition, (a)-(d) mentioned above is a modification of the injection | pouring with respect to the injector 12, and the excretion position and the injection axis | shaft 6 of the injector 12 are all the same as 1st Example.

Next, a modification of the arrangement of the arrangement of the valve stem 57 and the partition wall 21 will be described using FIGS. 26 to 29.

As described above, in the first embodiment of the present invention, the partition wall 21 as shown in FIG. 6 is formed to be narrow. This biases the inner surface 121a of the partition wall 21 to the side passage 5 from the inner surface of the valve stem 57. Thereby, the effect of concentrating the fuel spray of the mixer flow along the surface 121a of the partition wall 21 near the ignition plug 11 in the direction as indicated by P in FIG. 6 is obtained.

The arrangement shown in FIG. 27 makes the side passage 5 more comfortable with the inner surface of the partition wall 121A than the inner surface of the valve stem 57 for the purpose of obtaining the same effect as the first embodiment. The center line itself of the partition wall 21 is also biased with the axis of the valve stem 57.

The arrangements shown in Figs. 28 and 29 can be considered. The upstream and middle portions of the partition walls 121B and 121C are biased outward from the shaft center of the valve stem 57. Then, the ignition means side partition walls (inner wall surface) 122a and 123a in the downstream portions 122 and 123 of the partition walls 121B and 121C ignite the intake air on the ignition means side 4. It is inclined toward the center toward the plug 11. In this case, the intake air flows more smoothly toward the spark plug 11, which can further promote lean burn of the engine, and is very effective for a laminar combustion engine. In addition, in the example shown in FIG. 28, only the inner wall surface 122a of the partition wall 121B is bent, and the outer wall surface of the partition wall 121B is planar. In addition, in the example shown in FIG. 29, the thickness of the partition wall 121C is set substantially constant over its entire length, and the outer wall surface is bent together with the inner wall surface 122a of the partition wall 121B.

In this manner, at least the inner surface 21a of the partition wall 21 is biased slightly to the opposite side of the spark plug than the inner surface of the valve stem 57, or the inner wall surface 21a of the downstream end of the partition wall 21 itself. By inclining the spark plug toward the spark plug, the centralization of the fuel spray in the mixer flowing along the inner wall surface of the partition wall 21 toward the spark plug can be realized. The concentration of the mixer toward the spark plug is adjusted according to the setting of the inclined state of the inner wall surfaces 122a and 123a and the inclined state of the inner wall surfaces 21a and 121a, for example. Can be.

Next, as a modification of the partition wall structure with respect to the direction of the intake air flow flowing into the intake port 46, a description will be given using FIGS. 30 to 31. FIG.

In Example 1, the inner wall and outer wall of the partition wall 21 are set substantially parallel. This simplifies the shape in consideration of the manufacturing point. In consideration of preventing the intake air flowing into the intake ports 46A and 46B and preventing disturbance of the intake air in the portion of the valve stem 57, as shown in FIG. 30, the partition wall It is preferable to form the thickness of (21) thinner toward the upstream of the valve stem 57, and to form very thin at the upper end. Moreover, as it approaches the downstream valve stem 57, it is preferable to form so that it may become thickness substantially equal to the outer diameter of the valve stem 57 gradually. In this way, the flow of intake air can flow smoothly into the combustion chamber 30 without being disturbed by the partition wall 21 and the valve stem 57.

Next, modification examples of the intake manifold 14 connected to the upstream side of the intake port 46 and the same intake port 46 will be described using FIGS. 31 to 33.

As described above, in the first embodiment of the present invention, the upper half portions 46A-1 and 46B-1 of the intake port portions 46A and 46B are lower than the lower half portions 46A-2 and 46B-2. It is widening. However, by further improving the shape of the intake manifold connected to the upstream side of the intake port 46, stronger tumble flows Fa and Fm can be obtained in the combustion chamber 30.

In FIG. 31, reference numeral 14 denotes an intake manifold fixed to the side surface 28A of the cylinder head 28 and connected to an upstream end of the intake port 46. As shown in FIG. In addition, the cross-sectional shape of each part of the intake port 46 and the intake manifold 14 is comprised as shown in FIG. That is, in this intake manifold 14, the intake air flows smoothly into each of the intake ports 46A and 46B (i.e., does not lower the speed of the intake air). As shown in the figure, the cross-sectional shape is gradually changed from the upstream to the downstream, and the intake port 46A is provided at the lowest downstream side (Fig. 32 (c)) connected to the intake passage portions 14A and 14B. Each cross-sectional shape with the intake manifold 14 of the head 46B is formed to substantially match.

That is, in this intake manifold 14, the two intake passage portions 14A and 14B, as in the cross-sectional shape of each intake passage portion 46A and 46B, move upward in the lower half. The portions 14A-1 and 14B-1 are formed to have an eccentric shape that is relatively wider than the lower half portions 14A-2 and 14B-2.

As a result, the intake air is eccentric from the two intake passages 14A and 14B in the intake manifold 14 to the upper half portions 14A-1 and 14B-1 so that the intake port ( Since it flows into 46A and 46B, it is made to further promote formation of the tumble flow in each intake port 46A and 46B.

In the first embodiment, a partition wall is provided only in the intake port. However, as shown in FIG. 33, the intake manifold 14 has two intake passage portions 14A and 14B in the left and right directions for two minutes. It is also possible to provide partition walls 15 and 15. The partition wall 15 is provided from the upper end to the lower end of each of the intake passage portions 14A and 14B, whereby the central passage 4 of the intake air flows in the intake passage portions 14A and 14B, respectively. It is made for 2 minutes by the side passage 5 'of'). The partition wall 15 is provided upstream of the downstream end of the intake manifold 14, that is, near the joining surface with the intake ports 46A and 46B, and the intake manifold 14 is provided by the partition wall 15. And the intake airflow port 46A separates the intake air into the side passages 5 and 5 'of the central passages 4 and 4'. As a result, the intake air branched into the side passages 5 and 5 'of the central passages 4 and 4' is completely separated from the mixer and air, and the layering of the tumble flows Fa and Fm in the combustion chamber 30 is achieved. I can strengthen it.

Next, a second embodiment of the present invention applied to an engine having a plurality of intake ports having no partition wall in the intake port will be described with reference to FIGS. 34 to 36.

34 shows the layered combustion internal combustion engine according to the second embodiment, except for the shape of the top surface of the piston 26 and the shapes of the intake ports 46A and 46B. It is basically the same structure as the layered combustion internal combustion engine shown in FIG.

And the shape of the top surface of the piston 26 can employ | adopt the shape shown in FIG. 1, FIG. 4, or the shape shown in FIG. As shown in FIGS. 34 and 35, the cross-sectional shapes of the intake ports 46A and 46B have a substantially inverted triangle shape in which the upper half portion is wider than the lower cut portion. In addition, the intake ports 46A and 46B generally have a substantially straight shape, and are largely curved near the intake opening end to the combustion chamber 30. As shown in FIG. 36, a convex portion having an inner diameter larger than that of the intake openings of the intake ports 46A and 46B is mainly formed in the curved portion as shown in FIG.

As a result, from the intake port 46A, the mixer flows into the combustion chamber 30 while forming a sufficient tumble flow of air from the intake port 46B for lean combustion, and also ensuring a sufficient intake flow rate. It is possible to improve the combustion stability, the combustion efficiency, and the output, compared to the lean combustion internal combustion engine.

Further, in all the above embodiments, the tumble flow Fm of the mixer and the tumble flow Fa of air are generated in the combustion chamber 30. However, the present invention is not limited to this, and for example, it is also possible to provide fuel to the tumble flow Fa so as to generate the tumble flow Fa 'having an air-fuel ratio smaller than the tumble flow Fm instead of the tumble flow Fa of air. .

Claims (27)

Ignition provided in the combustion chamber 30 defined by the inner surface of the cylinder 24 and the upper surface 34 and the cylinder head lower surface 60 of the piston 26 inserted in the cylinder 24 and the inner surface of the combustion chamber 30. A plurality of intake openings disposed on one side of the virtual plane FC including the plug 11 and the cylinder axis L on the cylinder head lower surface 60 and opened and closed by the intake valves 58 and 58 respectively. And from one side of the imaginary plane FC along the cylinder head lower surface 60 from the intake opening so as to generate a tumble flow parallel to one another and substantially in the same direction within the combustion chamber 30 by intake air. The fuel is supplied to the intake air supply means 46 for introducing the intake air to the other side, and the intake air generating a tumble flow at a position corresponding to the spark plug 11 in the intake air supply means 46, whereby Said kite in administration And a fuel supply means 12 for presenting the layered tumble flow in the chamber 30, and along the flow direction of the tumble flow on the top surface 34 of the piston to promote the layered tumble flow. A layered combustion internal combustion engine characterized by having at least one slope (vf1). 2. The virtual plane FC of claim 1, wherein the slope vf1 is formed on the piston top surface 34, and the ridge 37 has its top on at least one of the virtual plane FC. A layered combustion internal combustion engine, characterized in that determined by the side of the side. 3. The piston top (34) according to claim 2, wherein the piston top (34) has a recess (35) adjacent to the virtual plane (FC) side of the ridge (37), and the recess (35) is the ridge ( 37) A layered combustion internal combustion engine characterized by having a surface smoothly continuous with the slope (vf4). 2. The ceiling of the combustion chamber (30) according to claim 1, wherein a compression stroke top dead center of the piston (26) is located near a portion farther from the virtual plane (FC) than the sloped end portion of the piston top surface (34). Layered combustion internal combustion engine, characterized in that it has a squash portion (vf2) for generating a squash (SF) in cooperation with the cylinder head lower surface (60) constituting. 3. The layered combustion internal combustion engine according to claim 2, wherein said raised portion (37) has its top only on said one side of said virtual plane (FC). 3. The layered combustion internal combustion engine according to claim 2, wherein the ridge (37) has its top only on the other side of the virtual plane (FC). 3. The layered combustion internal combustion engine according to claim 2, wherein the ridges (37) have their tops on each of the one side and the other side of the virtual plane FC. 3. The layered combustion internal combustion engine according to claim 2, wherein the intersection of the plane parallel to the virtual plane FC and the slope vf1.vfa is approximately straight. 3. The virtual plane FC according to claim 2, wherein in order to avoid interference between the piston top surface 34 and the intake valves 58 and 58 for opening and closing the intake openings, the imaginary plane FC is used. The layered combustion internal combustion engine, characterized in that the valve reset (39) is provided at a portion far from the. 10. The combustion chamber (30) according to claim 9, wherein said portion farther from said imaginary plane (FC) than said slopes (vf1, vf3, vf4) in said ridge (37) is near the compression stroke top dead center of said piston. A squamous combustion internal combustion engine, characterized in that to generate a squash (SF) in cooperation with the cylinder head lower surface (60) constituting the ceiling of the. The layered combustion internal combustion engine according to claim 1, wherein said slope (vf4) is formed by a surface of a recess (35) formed in said piston top surface (34). Ignition provided in the combustion chamber 30 defined by the inner surface of the cylinder 24 and the upper surface 34 and the cylinder head lower surface 60 of the piston 26 inserted in the cylinder 24 and the inner surface of the combustion chamber 30. It has two intake openings opened and closed by two intake valves 58 and 58 on one side of the virtual plane FC including the plug 11 and the cylinder axis L in the cylinder head lower surface 60. Intake air from one side of the virtual plane FC along the cylinder head lower surface 60 from the intake opening to the other in the combustion chamber 30 is substantially parallel to each other and generates a tumble flow in the same direction. An intake intake port 46 for introducing intake air, and is formed extending from the upper inner surface 8 of the intake port 46 toward the lower inner surface 7 and partitions the intake port 46 into a plurality; To divide the tumble stream into a plurality of parallel flows The fuel is supplied to at least one partition wall 21 and an intake air generating a tumble flow at a position corresponding to the spark plug 11 disposed at the ceiling center of the combustion chamber 30, thereby providing the fuel in the intake process. A layered combustion internal combustion engine comprising: a fuel supply means (12) for presenting a layered tumble flow in a combustion chamber (30). 13. The virtual plane FC of the ridge 37 according to claim 12, wherein the slope vf1 is formed on the piston top surface 34 and has its top on at least one side of the virtual plane FC. A layered combustion internal combustion engine, characterized in that determined by the upper surface of the side. 14. The piston top (34) according to claim 13, wherein the piston top surface (34) has a recess (35) adjacent to the virtual plane (FC) side of the ridge (37), and the recess (35) is the ridge ( 37) A layered combustion internal combustion engine characterized by having a surface smoothly continuous with the slope (vf4). 15. The ceiling of the combustion chamber 30 according to claim 13, which is formed near the compression stroke top dead center of the piston at a portion farther from the imaginary plane FC than the upper sloped end of the piston top surface 34. And a squash portion (vf2) for generating squash SF in cooperation with the cylinder head lower surface (60). 14. The layered combustion internal combustion engine according to claim 13, wherein the intersection of the plane parallel to the virtual plane FC and the slope (vf1. Vf4) is substantially straight. The virtual plane FC according to claim 13, wherein in order to avoid interference between the piston top surface 34 and the intake valves 58 and 58 for opening and closing the intake openings, the virtual plane FC is formed from the upper end of the slope in the ridge 37. The layered combustion internal combustion engine, characterized in that the valve reset (39) is provided at a portion far from the. 14. The combustion chamber (30) according to claim 13, wherein said portion of said ridge (37) farther from said imaginary plane (FC) than said slopes (vf1, vf3, vf4) is near the compression stroke top dead center of said piston. A squamous combustion internal combustion engine, characterized in that to generate a squash (SF) in cooperation with the cylinder head lower surface (60) constituting the ceiling of the. 14. The layered combustion internal combustion engine according to claim 13, wherein said slope (vf4) is formed by a surface of a recess (35) formed in said piston top surface (34). Ignition provided in the combustion chamber 30 defined by the inner surface of the cylinder 24 and the upper surface 34 and the cylinder head lower surface 60 of the piston 26 fitted in the same cylinder 24, and the ignition provided in the inner surface of the said combustion chamber 30. A plurality of intake openings disposed on one side of the virtual plane FC including the plug 11 and the cylinder axis L on the cylinder head lower surface 60 and opened and closed by the intake valves 58 and 58 respectively. The virtual plane FC along the cylinder head lower surface 60 from the intake opening so as to generate a tumble flow parallel to one another and substantially in the same direction in the combustion chamber 30 by intake air. Intake fuel 46 that flows intake air from one side to the other, and intake fuel that generates a tumble flow at a position corresponding to an ignition plug disposed on the cylinder head lower surface 60 constituting the ceiling of the combustion chamber 30. Supply, thereby absorbing In the stroke the combustion chamber 30, a layer-burn internal combustion engine, characterized in that a fuel supply means (12) to present the tumble flow of the layer-within. 21. The virtual plane FC of claim 20, wherein the slope vf1 is formed on the piston top surface 34 and has a normal shape on at least one side of the virtual plane FC. A layered combustion internal combustion engine, characterized in that determined by the side of the side. 22. The method according to claim 21, wherein the piston top surface 34 has a recessed portion 35 adjacent to the virtual plane FC side of the raised portion 37, the recessed portion 35 being the raised portion ( 37. The layered combustion internal combustion engine, characterized in that it has a smoothly continuous surface with said slope (vf4). 22. The ceiling of the combustion chamber (30) according to claim 21, wherein the ceiling of the combustion chamber (30) is positioned near the compression stroke top dead center of the piston (26) at a portion farther from the imaginary plane (FC) than the upper end surface of the top surface (34) of the piston. And a squash portion (vf2) for generating squash SF in cooperation with the cylinder head lower surface (60) to be configured. 22. The layered combustion internal combustion engine according to claim 21, wherein the intersection of the plane parallel to the virtual plane FC and the slope vf1.vf4 is substantially straight. 22. The virtual plane FC according to claim 21, in order to avoid interference between the piston top surface 34 and the intake valves 58 and 58 that open and close the intake openings. The layered combustion internal combustion engine, characterized in that the valve recess (39) is provided at a portion far from the. 22. The combustion chamber as set forth in claim 21, wherein said portion farther from said imaginary plane (FC) than said slopes (vf1, vf3, vf4) in said ridge (37) is near said compression stroke top dead center of said piston (26). A squamous combustion internal combustion engine characterized by generating squash (SF) in cooperation with a cylinder head lower surface (60) constituting the ceiling of (30). A layered combustion internal combustion engine as set forth in claim 21, wherein said slope (vf4) is formed by a surface of a recess (35) formed in said piston top surface (34).