WO2016181483A1 - Moteur à deux soupapes - Google Patents

Moteur à deux soupapes Download PDF

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Publication number
WO2016181483A1
WO2016181483A1 PCT/JP2015/063565 JP2015063565W WO2016181483A1 WO 2016181483 A1 WO2016181483 A1 WO 2016181483A1 JP 2015063565 W JP2015063565 W JP 2015063565W WO 2016181483 A1 WO2016181483 A1 WO 2016181483A1
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WO
WIPO (PCT)
Prior art keywords
ignition
center
intake
combustion chamber
viewed
Prior art date
Application number
PCT/JP2015/063565
Other languages
English (en)
Japanese (ja)
Inventor
隼人 田之倉
鈴木　実
真前 伊藤
洋平 岩城
Original Assignee
ヤマハ発動機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ヤマハ発動機株式会社 filed Critical ヤマハ発動機株式会社
Priority to EP15891808.6A priority Critical patent/EP3296551B1/fr
Priority to PCT/JP2015/063565 priority patent/WO2016181483A1/fr
Publication of WO2016181483A1 publication Critical patent/WO2016181483A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M35/00—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines
    • F02M35/16—Combustion-air cleaners, air intakes, intake silencers, or induction systems specially adapted for, or arranged on, internal-combustion engines characterised by use in vehicles
    • F02M35/162—Motorcycles; All-terrain vehicles, e.g. quads, snowmobiles; Small vehicles, e.g. forklifts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B31/00—Modifying induction systems for imparting a rotation to the charge in the cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/24—Cylinder heads
    • F02F1/42—Shape or arrangement of intake or exhaust channels in cylinder heads
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F3/00—Pistons 
    • F02F3/26—Pistons  having combustion chamber in piston head
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B2023/102—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder the spark plug being placed offset the cylinder centre axis
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B2023/106—Tumble flow, i.e. the axis of rotation of the main charge flow motion is horizontal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B2023/108—Swirl flow, i.e. the axis of rotation of the main charge flow motion is vertical

Definitions

  • the present invention relates to a two-valve engine.
  • Non-Patent Document 1 discloses an engine in which fuel efficiency is improved by strengthening a tumble flow that is a vortex of an air-fuel mixture in a combustion chamber.
  • the engine of Non-Patent Document 1 is a four-stroke engine for a small motorcycle and a two-valve engine.
  • a two-valve engine such as that shown in Non-Patent Document 1
  • the flow of the air-fuel mixture is strengthened by increasing the tumble flow, so the combustion of the air-fuel mixture becomes rapid. That is, the main combustion period in the expansion stroke, that is, the crank angle section in which a predetermined majority of fuel in the combustion chamber burns is shortened.
  • the pressure increase rate in the expansion stroke is increased. This brings the pressure-volume characteristic closer to the ideal state and increases work efficiency. Therefore, fuel consumption is improved.
  • Non-Patent Document 1 a roller bearing is adopted as the journal bearing that supports the crankshaft.
  • propagation of combustion noise is suppressed by improving the support rigidity of the crankshaft by roller bearings.
  • An object of the present invention is to provide a two-valve engine that improves fuel consumption and suppresses the generation of combustion noise.
  • the present invention adopts the following configuration in order to solve the above-described problems.
  • a two-valve engine The two-valve engine A crankshaft, A rolling bearing for supporting the crankshaft; A piston portion connected to the crankshaft; A cylinder head portion having one intake port that communicates with the intake passage and is opened and closed by an intake valve, and one exhaust port that communicates with the exhaust passage and is opened and closed by an exhaust valve, and accommodates the piston portion therein
  • a cylinder body portion having a cylinder bore, and a cylinder portion forming a combustion chamber together with the piston portion;
  • a fuel injection section for injecting fuel into the intake passage; Provided in one of the two regions defined by dividing the combustion chamber by a straight line passing through the center of the intake port and the center of the exhaust port when viewed in the direction of the central axis of the cylinder bore
  • an ignition part The piston part has a concave part that is recessed from the periphery on the top surface of the piston part, and the concave part is not provided with the ignition part when viewed in the direction of the central axis of the cylinder
  • An area where the region and the concave portion overlap is formed to be smaller than an area where the region where the ignition unit is provided and the concave portion are overlapped,
  • the intake passage is viewed in the direction of the central axis of the cylinder bore, the area where the area overlapping with the recess is small and the ignition part is not disposed is the center of the intake port. It is provided so as to be arranged on a straight line extending from the center line of the intake passage.
  • the piston portion is accommodated in a cylinder bore included in the cylinder body portion.
  • the cylinder head portion has one intake port communicating with the intake passage and one exhaust port communicating with the exhaust passage.
  • the intake port is opened and closed by an intake valve
  • the exhaust port is opened and closed by an exhaust valve.
  • the cylinder part forms a combustion chamber together with the piston part.
  • the ignition unit is not arranged on a straight line passing through the center of the intake port and the center of the exhaust port.
  • the ignition unit is provided in one of the two regions defined by dividing the combustion chamber by the straight line. Fuel is injected into the intake passage by the fuel injection unit.
  • the air-fuel mixture containing fuel enters the combustion chamber from the intake passage through the intake port as the piston moves.
  • the air-fuel mixture in the combustion chamber burns by ignition of the ignition unit.
  • a vortex of the air-fuel mixture is generated in the combustion chamber.
  • the intake passage is provided such that when viewed in the direction of the center axis of the cylinder bore, a straight line extending the center line of the intake passage from the center of the intake port passes through a region where no ignition portion is disposed. For this reason, the vortex of the air-fuel mixture in the combustion chamber has a swirl component around the central axis and a tumble component around a line perpendicular to the central axis. That is, a flow in which the swirl flow and the tumble flow are combined is generated in the combustion chamber.
  • tumble flow When viewed in the direction of the central axis, the main tumble flow of the air-fuel mixture entering the combustion chamber from the intake port (simply referred to as tumble flow) flows along a straight line extending from the intake port to the center line of the intake passage.
  • the direction of the tumble flow is not directed from the intake port to the exhaust port but is inclined.
  • the tumble flow is directed from the center of the intake port through the region where the ignition unit is not disposed, of the two regions. Since the tumble flow rotates around a line perpendicular to the central axis, the oblique direction of the tumble flow is the same not only in the vicinity of the intake port but also in the vicinity of the ignition unit. That is, the direction of the tumble flow in the vicinity of the ignition part includes a component directed from the intake port to the exhaust port and a component directed from the ignition part to a region where the ignition part is not disposed. On the other hand, the swirl flow of the air-fuel mixture rotates around the central axis.
  • the swirl flow rotates around the central axis in a direction passing through the intake port, the exhaust port, and the ignition unit in this order.
  • the direction of the swirl flow around the ignition part is the direction from the exhaust port to the intake port.
  • the piston portion has a concave portion that is recessed from the periphery on the top surface of the piston portion. When viewed in the direction of the center axis of the cylinder bore, the area where the igniting part is not provided and the recessed part of the above two areas is larger than the area where the igniting part is provided and the recessed part is overlapped. small.
  • the region where the area overlapping the recess is small and the ignition unit is not disposed is disposed on a straight line extending from the center of the intake port to the center line of the intake passage. For this reason, the swirl flow caused by the air-fuel mixture entering the combustion chamber from the intake passage is more likely to be maintained centering on the region where the area overlapping the recess is larger than the area where the area overlapping the recess is small, that is, the region where the ignition unit is disposed. . For this reason, even when the piston moves to the top dead center, the swirl flow of the air-fuel mixture is easily maintained around the ignition unit.
  • a combined flow of the tumble flow and the swirl flow is generated in the combustion chamber.
  • the component directed from the intake port to the exhaust port is attenuated by the swirl flow in the opposite direction.
  • the air-fuel mixture around the ignition part flows from the area where the ignition part is arranged, toward the area where the ignition part is not arranged, of the above two areas.
  • the flame generated in the combustion chamber by ignition of the ignition unit proceeds along the flow of the air-fuel mixture itself.
  • the component of the tumble flow from the intake port to the exhaust port is reduced by the swirl flow.
  • the main combustion period in the expansion stroke is shortened.
  • the main combustion period in the expansion stroke is shortened even though it is possible to suppress the rapid progress of the flame toward the exhaust port at the early stage of combustion. Therefore, the fuel efficiency of the two-valve engine is improved. Therefore, according to the two-valve engine of the present invention, it is possible to suppress the generation of combustion noise while improving fuel efficiency.
  • the two-valve engine of (1) The intake passage is provided so as to form an arc that curves on the upstream side of the intake port when viewed in the direction of the central axis of the cylinder bore;
  • the ignition portion is provided outside the curved arc when viewed in the direction of the central axis of the cylinder bore.
  • the intake passage forms an arc that is curved on the upstream side of the intake port, and the ignition portion is provided outside the arc, so that the swirl flow of the air-fuel mixture that has passed through the intake passage is reduced. growing. For this reason, the swirl flow of the air-fuel mixture in the combustion chamber is easily maintained. Therefore, it is possible to further suppress the generation of combustion noise while further improving the fuel consumption.
  • the two-valve engine according to (1) or (2), The concave portion has a spherical shape.
  • the recess Since the recess has a spherical shape, the bottom of the combustion chamber spreads into a spherical shape. For this reason, the swirl flow of the air-fuel mixture in the combustion chamber is more easily maintained. Therefore, it is possible to further suppress the generation of combustion noise while further improving the fuel consumption.
  • the two-valve engine according to any one of (1) to (3),
  • the piston portion is provided in a region on the top surface opposite to the ignition portion across a straight line passing through the center of the intake port and the center of the exhaust port when viewed in the direction of the central axis of the cylinder bore. Having a convex portion.
  • the space corresponding to the region provided with the convex portion in the combustion chamber is narrowed, so that the progress of the flame is delayed.
  • the progress of the flame is delayed in a region opposite to the ignition portion when viewed in the direction of the central axis, and is a portion related to combustion after the combustion in the main combustion period is completed. In the region opposite to the ignition unit, an unburned state of the air-fuel mixture tends to occur.
  • the configuration of (4) since the progress of the flame is delayed, the high temperature state of the air-fuel mixture is maintained for a long time, so that the air-fuel mixture is sufficiently easily combusted. Therefore, it is possible to further improve the fuel consumption, further suppress the generation of combustion noise, and suppress the discharge of unburned air-fuel mixture from the two-valve engine.
  • a straight line extending the center line of the intake passage from the center of the intake port extends through a region where the ignition unit is not disposed.
  • the swirl flow of the air-fuel mixture is promoted. Therefore, it is possible to further suppress the generation of combustion noise while further improving the fuel consumption.
  • FIG. 1 is a longitudinal sectional view showing a schematic configuration of a two-valve engine according to an embodiment of the present invention. It is a longitudinal section in another direction which shows schematic structure of a 2 valve engine concerning one embodiment of the present invention. It is the expanded sectional view which expanded the combustion chamber vicinity of the engine shown in FIG. FIG. 3 is an enlarged cross-sectional view in which the vicinity of a combustion chamber of the engine shown in FIG. 2 is enlarged.
  • (A) is sectional drawing which shows the engine of the 1st reference example provided with the protrusion part for generation
  • B) is sectional drawing which shows the engine of the 2nd reference example provided with another protrusion part for generation
  • FIG. 3 is a perspective view of the internal structure of the cylinder head portion shown in FIGS. 1 and 2 when viewed from the central axis of the cylinder bore. It is a figure which shows a top surface when a piston part is seen in the direction of the center axis line of a cylinder bore. It is a figure which shows arrangement
  • a comparative example of the present embodiment it is a schematic diagram showing the flow of an air-fuel mixture in an engine in which a swirl flow is not substantially generated. It is a graph for demonstrating the combustion state of the air-fuel mixture in an engine.
  • the inventors of the present invention conducted intensive research in order to achieve both improvement in fuel consumption and reduction in combustion noise, and obtained the following knowledge.
  • Both fuel consumption and combustion noise are affected not only by the main combustion period but also by the degree of progress over time of combustion.
  • the impact that affects the combustion noise greatly depends on the pressure increase rate in the early stage of combustion. Therefore, if the increase rate of the combustion amount of the air-fuel mixture can be increased in the later stage of combustion while suppressing the increase rate of the combustion amount of the air-fuel mixture in the early stage of combustion, the main combustion period that contributes to fuel efficiency can be shortened, and An initial pressure increase rate can be suppressed.
  • the inventors have introduced a swirl flow into a combustion chamber of a two-valve engine in which a tumble flow is generated, and maintained a long swirl flow by a recess provided on the top surface of the piston portion, thereby improving fuel consumption and improving combustion noise.
  • the knowledge that can be suppressed Specifically, by introducing the swirl flow by devising the arrangement of the intake passage, the speed at which the air-fuel mixture around the ignition part in the combustion chamber flows to the exhaust port can be suppressed. As a result, the pressure increase rate in the initial stage of combustion can be suppressed.
  • the ignition section is devised to direct the tumble flow to the exhaust port at an angle, and by introducing the swirl flow, the igniting section is arranged by combining the tumble flow and swirl flow around the ignition section.
  • the area is directed to the area where the ignition part is not arranged. This increases the rate of increase in the amount of combustion of the air-fuel mixture in the later stage of combustion. As a result, the main combustion period can be shortened.
  • the present invention is based on the knowledge that it is possible to achieve both improvement in fuel consumption and reduction in combustion noise by introducing and maintaining a swirl flow with respect to the conventional design concept that employs a type of bearing having high support rigidity. It is a completed invention.
  • FIG. 1 and 2 are longitudinal sectional views showing a schematic configuration of a two-valve engine 1 according to an embodiment of the present invention.
  • X indicates the direction in which the rotation axis M of the crankshaft 2 extends.
  • Z indicates the direction in which the central axis C of the cylinder bore 42b extends (the direction in which the piston portion 5 reciprocates).
  • Y indicates a direction orthogonal to both the rotation axis direction X of the crankshaft 2 and the center axis direction Z of the cylinder bore 42b.
  • FIG. 1 is a longitudinal sectional view schematically showing the two-valve engine 1 when viewed from the direction Y.
  • FIG. 2 is a longitudinal sectional view schematically showing the two-valve engine 1 when viewed from the direction X. As shown in FIG.
  • a two-valve engine 1 (hereinafter also simply referred to as the engine 1) shown in FIGS. 1 and 2 is mounted on a straddle-type vehicle (not shown) represented by a motorcycle, for example.
  • the vehicle when the engine 1 is mounted on a vehicle, the vehicle is not limited to a straddle-type vehicle such as a motorcycle.
  • the vehicles include various types of vehicles such as automobiles and snowmobiles.
  • the number of wheels of the vehicle on which the engine 1 is mounted is not particularly limited.
  • the engine 1 may be mounted on a device or device (for example, a generator) other than the vehicle.
  • the engine 1 is a single-cylinder four-stroke engine.
  • the engine 1 includes a crankshaft 2, a crankcase part 3, a cylinder part 4, a piston part 5, a fuel injection part 6, an ignition part 7, an intake valve 8a, and an exhaust valve 8b.
  • an engine 1 mounted on a saddle-ride type vehicle (not shown) will be described.
  • the engine 1 is arranged in the saddle type vehicle so that the direction X substantially matches the width direction of the saddle type vehicle and the direction Y substantially matches the front-rear direction of the saddle type vehicle.
  • the direction X is also referred to as the width direction of the engine 1.
  • the direction Y is also referred to as the front-rear direction of the engine 1.
  • the posture in which the engine 1 is mounted on the vehicle is not limited to this embodiment.
  • the front-rear direction Y of the engine 1 is not limited to a direction parallel to the horizontal plane, and may be oblique to the horizontal plane. That is, the front-rear direction Y of the engine 1 may be oblique with respect to the front-rear direction of the saddle riding type vehicle.
  • the cylinder part 4 includes a cylinder head part 41 and a cylinder body part 42.
  • the crankcase portion 3, the cylinder body portion 42, and the cylinder head portion 41 are stacked in this order and fastened to each other. In FIG. 2, the crankcase portion 3 is not shown for ease of viewing the structure.
  • the engine 1 includes a bearing 31 that rotatably supports the crankshaft 2.
  • the bearing 31 is a rolling bearing.
  • the bearing 31 is a ball bearing, for example.
  • the crankshaft 2 is supported on the crankcase portion 3 by a bearing 31.
  • the crankcase portion 3 is composed of two case portions 3a divided in the width direction X as shown in FIG.
  • the crankcase portion 3 is configured by fastening the two case portions 3a in the width direction X.
  • Each of the two case portions 3a is formed with a support portion 3b for supporting the bearing 31.
  • a bearing 31 is fitted in the support portion 3b of each case portion 3a.
  • Each bearing 31 supports each journal of the crankshaft 2 extending in the width direction X.
  • a cylinder bore 42b is formed in the cylinder body portion 42.
  • the cylinder bore 42b is a space in the cylinder body portion 42, and has a cylindrical shape extending in the direction Z in this embodiment.
  • the piston part 5 is accommodated in the cylinder bore 42b.
  • the piston part 5 is disposed so as to be able to reciprocate in the direction Z.
  • the piston portion 5 is connected to the crankshaft 2 via a connecting rod 32.
  • One end of the connecting rod 32 is rotatably supported by the crankshaft 2, and the other end of the connecting rod 32 is rotatably supported by the piston portion 5.
  • the crankshaft 2 rotates.
  • the cylinder part 4 and the piston part 5 form a combustion chamber 4r.
  • the engine 1 of the present embodiment is an air-cooled engine, and heat radiation fins 41h and 42h are provided outside the cylinder head portion 41 and outside the cylinder body portion 42, respectively.
  • the cylinder head portion 41 is formed with one intake passage 41a and one exhaust passage 41e. Each of the intake passage 41a and the exhaust passage 41e continues to the combustion chamber 4r.
  • the cylinder head portion 41 has an intake port 41b and an exhaust port 41f.
  • the intake port 41b is an opening in the combustion chamber 4r of the intake passage 41a.
  • the exhaust port 41f is an opening in the combustion chamber 4r of the exhaust passage 41e.
  • the intake port 41b and the exhaust port 41f communicate with the intake passage 41a and the exhaust passage 41e, respectively.
  • the intake port 41b is opened and closed by the intake valve 8a.
  • the exhaust port 41f is opened and closed by an exhaust valve 8b.
  • the intake passage 41a is formed to extend upstream in the cylinder head portion 41 while bending from the intake port 41b of the combustion chamber 4r.
  • An end (upstream end) opposite to the intake port 41 b in the intake passage 41 a is open to the outer surface of the cylinder head portion 41.
  • the intake pipe 43 is connected to the end (upstream end) of the intake port 41b.
  • the exhaust passage 41e is formed so as to extend downstream in the cylinder head portion 41 while bending from the exhaust port 41f of the combustion chamber 4r.
  • the opposite end (downstream end) of the exhaust port 41f in the exhaust passage 41e opens to the outer surface of the cylinder head portion 41.
  • An exhaust pipe (not shown) is connected to the end (downstream end) of the exhaust port 41f.
  • the fuel injection part 6 is attached to the cylinder head part 41 so as to face the intake passage 41a.
  • the fuel injection unit 6 injects fuel into the intake passage 41a.
  • the fuel injection unit 6 injects fuel to a position upstream of the intake port 41b.
  • the fuel injection unit 6 creates an air-fuel mixture by injecting fuel into the outside air flowing through the intake passage 41a.
  • the air-fuel mixture contains air and fuel.
  • the air-fuel mixture is supplied to the combustion chamber 4r through the intake port 41b.
  • the cylinder head portion 41 is provided with a cam shaft 41s so as to be rotatable.
  • a cam 41t is provided on the cam shaft 41s.
  • the camshaft 41s and the cam 41t are integrated and rotate in conjunction with the rotation of the crankshaft 2.
  • the cylinder head part 41 is provided with an ignition part 7.
  • the ignition unit 7 is a part that ignites the air-fuel mixture in the combustion chamber 4r.
  • the ignition part 7 is a part exposed to the combustion chamber 4 r in the spark plug 70 attached to the cylinder head part 41.
  • the engine 1 of the present embodiment includes only one intake valve 8a and only one exhaust valve 8b with respect to one cylinder bore 42b. That is, only one intake passage 41a and only one exhaust passage 41e are connected to one combustion chamber 4r. One combustion chamber 4r has only one intake port 41b and only one exhaust port 41f.
  • the combustion chamber 4r has a non-squish region N on at least a part of the outer periphery of the combustion chamber 4r in the radial direction of the cylinder bore 42b.
  • the non-squish region N is a region where at least the cylinder head portion 41 of the cylinder head portion 41 and the piston portion 5 is not provided with a protruding portion for generating a squish effect.
  • the squish effect is that a part of the air-fuel mixture sandwiched between the top surface 5t of the piston part 5 and the cylinder head part 41 is pushed out as the piston part 5 rises, so that the flow of the air-fuel mixture flows into the combustion chamber 4r. This is the effect of forming turbulence and / or vortices.
  • FIG. 3 is an enlarged cross-sectional view in which the vicinity of the combustion chamber 4r of the engine 1 shown in FIG. 1 is enlarged.
  • FIG. 4 is an enlarged sectional view in which the vicinity of the combustion chamber 4r of the engine 1 shown in FIG. 2 is enlarged. 3 and 4, it is shown that the combustion chamber 4r has a non-squish region N on the outer periphery of the combustion chamber 4r in the radial direction of the cylinder bore 42b. In the non-squish region N, the cylinder head portion 41 is not provided with a protruding portion for generating a squish effect.
  • the cylinder head portion 41 and the piston portion 5 are not provided with protruding portions for generating a squish effect.
  • a step is not substantially provided at a portion where the upper surface of the cylinder head portion 41 and the inner peripheral surface of the cylinder body portion 42 are adjacent to each other.
  • the separation distance between the cylinder head portion 41 and the piston portion 5 in the central axis direction Z of the cylinder bore 42b is continuously increased from the outside to the inside in the radial direction of the cylinder bore 42b.
  • FIG. 5A is a cross-sectional view showing a first reference example engine provided with a protrusion for generating a squish effect.
  • FIG. 5B is a cross-sectional view showing an engine of a second reference example in which another protrusion is provided.
  • the engine 8 of the first reference example shown in FIG. 5 (A) is the engine disclosed in Patent Document 1.
  • the engine 8 of the first reference example shown in FIG. 5A has a squish region S on the outer periphery of the combustion chamber 84r in the radial direction.
  • the cylinder head portion 841 is provided with a protruding portion 849.
  • the piston portion 85 is provided with a protruding portion 859.
  • the protruding portion 849 of the cylinder head portion 841 is provided such that the separation distance between the cylinder head portion 841 and the piston portion 85 in the central axis direction is substantially maintained from the outer side to the inner side in the radial direction. .
  • the air-fuel mixture sandwiched between the piston portion 85 and the cylinder head portion 841 in the squish region S is increased in the radial direction as the piston portion 85 rises. Pushed inward. That is, the squish effect is generated in the engine 8 of the first reference example.
  • the engine 9 of the second reference example shown in FIG. 5B also has a squish region S on the outer periphery of the combustion chamber 94r in the radial direction.
  • the cylinder head portion 941 is provided with a protruding portion 949.
  • the projecting portion 949 of the cylinder head portion 941 is formed by a step provided in a portion where the upper surface of the cylinder head portion 941 and the inner peripheral surface of the cylinder body portion 942 are adjacent to each other.
  • the piston portion 985 is provided with a protruding portion 959.
  • the separation distance between the cylinder head portion 941 and the piston portion 95 in the central axis direction continuously decreases from the outside toward the inside in the radial direction. For this reason, in the engine 9 of the reference example shown in FIG. 5B, the air-fuel mixture sandwiched between the piston portion 95 and the cylinder head portion 941 in the squish region S Pushed inward. That is, the squish effect also occurs in the engine 9 of the second reference example.
  • the non-squish region N in the present embodiment is not provided with a protruding portion for generating a squish effect, such as the protruding portion 859 shown in FIG.
  • the step shown in FIG. 5B is not provided, and the protruding portion for generating the squish effect, such as the protruding portion 959 shown in FIG. Is not provided.
  • FIG. 6 is a perspective view of the internal structure of the cylinder head portion 41 shown in FIGS. 1 and 2 when viewed in the direction Z of the central axis C of the cylinder bore 42b.
  • FIG. 6 shows each part in the cylinder head part 41 when viewed from the cylinder head part 41 toward the crankshaft 2.
  • FIG. 6 also schematically shows valve support portions 81a and 81b that support the intake valve 8a and the exhaust valve 8b, respectively, and the fuel injection portion 6.
  • the engine 1 of this embodiment is a two-valve engine.
  • the combustion chamber 4r When viewed in the direction Z of the central axis C of the cylinder bore 42b, the combustion chamber 4r has a circular shape or a substantially circular shape.
  • one intake port 41b and one exhaust port 41f are arranged side by side.
  • the intake port 41b and the exhaust port 41f are arranged in the front-rear direction Y and spaced apart from each other.
  • the area of the exhaust port 41f is smaller than the area of the intake port 41b.
  • both the intake port 41b and the exhaust port 41f generally overlap the combustion chamber 4r.
  • the entire exhaust port 41f overlaps the intake port 41b in the front-rear direction Y.
  • the center 41g of the exhaust port 41f overlaps the intake port 41b in the front-rear direction Y.
  • the center 41c of the intake port 41b overlaps the exhaust port 41f in the front-rear direction Y.
  • the central axis C of the cylinder bore 42b is located between the intake port 41b and the exhaust port 41f in the front-rear direction Y.
  • the central axis C of the cylinder bore 42b overlaps both the intake port 41b and the exhaust port 41f in the front-rear direction Y.
  • the ignition unit 7 is disposed at a position away from the central axis C of the cylinder bore 42b.
  • the ignition unit 7 is arranged at a position away from the center of the combustion chamber 4r when viewed in the direction of the central axis C.
  • the igniter 7 is located in the front-rear direction Y between the center 41c of the intake port 41b and the center 41g of the exhaust port 41f.
  • the combustion chamber 4r is divided into two regions by a straight line D passing through the center 41c of the intake port 41b and the center 41g of the exhaust port 41f.
  • the ignition unit 7 is provided in one of the two regions. Of the two regions, a region where the ignition unit 7 is provided is referred to as an ignition unit region E. A region where the ignition unit 7 is not provided is referred to as a non-ignition unit region F.
  • the ignition part region E and the non-ignition part region F are defined by being divided by a straight line D.
  • the intake passage 41a in the engine 1 is directed obliquely with respect to the exhaust port 41f.
  • the center line P of the intake passage 41a extends to the center 41c of the intake port 41b.
  • a straight line Q extending the center line P of the intake passage 41a from the center 41c of the intake port 41b does not pass through the center 41g of the exhaust port 41f.
  • the straight line Q is a half straight line extending in the downstream direction from the center 41c of the intake port 41b toward the combustion chamber 4r.
  • the straight line Q is a straight line extending from the center 41c with the direction of the center line P of the intake passage 41a at the center 41c of the intake port 41b. Further, as described above, the combustion chamber 4r has the non-squish region N on at least a part of the outer periphery of the combustion chamber 4r in the radial direction of the cylinder bore 42b. When viewed in the direction of the central axis C, a straight line Q extending from the center 41c of the intake port 41b passes through the non-ignition part region F and the non-squish region N. That is, when viewed in the direction of the central axis C, the non-ignition part region F and the non-squish region N are arranged on the straight line Q.
  • the straight line Q when viewed in the direction of the central axis C, the straight line Q extends through the non-ignition part region F to the non-squish region N without overlapping the exhaust port 41f.
  • the intersection V between the outer edge of the combustion chamber 4r and the straight line Q is located forward (downstream) from the center 41c of the intake port 41b.
  • the intersection V is located forward (downstream) from the center axis C of the cylinder bore 42b.
  • the combustion chamber 4r has a non-squish region N over the entire non-ignition portion region F where the ignition portion 7 is not disposed at the outer periphery of the combustion chamber 4r. More specifically, the combustion chamber 4r has a non-squish region N on the entire outer periphery of the combustion chamber.
  • the intake passage 41a is inclined with respect to the exhaust port 41f.
  • the center line P of the intake passage 41a extending in the intake passage 41a to the center 41c of the intake port 41b passes through the ignition region E, but is not in the non-ignition region F. Do not pass over.
  • the intake passage 41a is provided so as to form an arc that curves on the upstream side of the intake port 41b when viewed in the direction of the central axis C of the cylinder bore 42b.
  • the ignition unit 7 is provided outside the arc.
  • the arc is not particularly limited, and examples thereof include an arc as a part of a perfect circle or a substantially perfect circle, and an arc as a part of an ellipse or a substantially ellipse.
  • the intake valve 8a and the exhaust valve 8b are supported by valve support portions 81a and 81b provided in the intake passage 41a and the exhaust passage 41e, and extend to the intake port 41b and the exhaust port 41f.
  • the opening direction G of the intake port 41b is the same as or substantially the same as the opening / closing direction of the intake valve 8a.
  • the opening direction G of the intake port 41b faces rearward (downstream) in the front-rear direction Y and faces downward in the direction Z (direction toward the piston portion 5).
  • FIG. 7 is a view showing the top surface 5t when the piston portion 5 is viewed in the direction of the central axis C of the cylinder bore 42b.
  • the shape of the piston portion 5 will be described with reference to FIGS. 3, 4, and 7.
  • the piston part 5 has a recessed part 5 c that is recessed from the periphery on the top surface 5 t of the piston part 5.
  • the recess 5c is circular when viewed in the direction of the central axis C of the cylinder bore 42b.
  • the recess 5c has a spherical shape.
  • valve recesses 5a and 5b for avoiding interference with the intake valve 8a and the exhaust valve 8b are also provided on the top surface 5t of the piston portion 5.
  • the valve recesses 5a and 5b are adjacent to the recess 5c. A part of the intake valve 8a and the exhaust valve 8b is received in the valve recesses 5a and 5b.
  • the recess 5c is a part different from the valve recesses 5a and 5b, and does not receive the intake valve 8a and the exhaust valve 8b.
  • the concave portion 5 c is unevenly distributed in the width direction X on the top surface 5 t of the piston portion 5. When viewed in the direction of the central axis C of the cylinder bore 42b, the area where the recess 5c and the ignition part region E overlap is larger than the area where the recess 5c and the non-ignition part region F overlap.
  • the concave portion 5c has a spherical shape such that the deepest portion of the concave portion 5c is disposed in the ignition portion region E.
  • the straight line Q extending from the center 41c of the intake port 41b passes through the non-ignition part region F where the area overlapping with the recess 5c is small and the ignition part 7 is not disposed. That is, when viewed in the direction of the central axis C, the non-ignition part region F in which the area overlapping with the recess 5c is small and the ignition part 7 is not disposed is disposed on the straight line Q.
  • a convex portion 5p is provided on the top surface 5t of the piston portion 5 (see FIG. 3).
  • the convex portion 5 p protrudes from the top surface 5 t of the piston portion 5 toward the cylinder head portion 41.
  • the convex portion 5p protrudes toward the cylinder head portion 41 from the outer peripheral portion of the top surface 5t in the radial direction of the cylinder bore 42b.
  • the protrusion 5p is disposed in the non-ignition part region F when viewed in the direction of the central axis C of the cylinder bore 42b.
  • the convex portion 5p and the concave portion 5c are arranged side by side in the width direction X.
  • the convex portion 5p is adjacent to the concave portion 5c.
  • the convex portion 5p has an arc shape in contact with the edge of the circular concave portion 5c when viewed in the direction of the central axis C of the cylinder bore 42b.
  • the vortex of the air-fuel mixture in the combustion chamber 4r has a swirl component around the central axis C and a tumble component around a line perpendicular to the central axis C. That is, a flow in which the swirl flow and the tumble flow are combined is generated in the combustion chamber.
  • the air-fuel mixture in the intake passage 41a flows radially from an annular gap generated in the intake port 41b by the operation of the intake valve 8a.
  • the flow of the air-fuel mixture in the portion close to the outer periphery of the combustion chamber 4r in the annular gap around the intake valve 8a is the inner wall of the outer periphery of the combustion chamber 4r.
  • the flow rate of the air-fuel mixture in the portion near the outer periphery of the combustion chamber 4r is smaller than the flow rate of the air-fuel mixture in the portion near the center of the combustion chamber 4r. Therefore, as a whole, the air-fuel mixture tends to move toward the center of the combustion chamber 4r after entering the combustion chamber 4r from the intake port 41b when viewed in the direction of the central axis C. Furthermore, the air-fuel mixture has inertia and viscosity. The direction of the flow of the air-fuel mixture when the air-fuel mixture passes through the intake passage 41a and enters the combustion chamber 4r is affected by the direction and shape of the intake passage 41a.
  • FIG. 8 is a diagram showing the arrangement of main parts and the flow of the air-fuel mixture in the combustion chamber 4r of the engine 1.
  • Three arrows T1 to T3 in FIG. 8 schematically show the direction of the tumble flow.
  • Arrows T1 to T3 indicate the flow of the air-fuel mixture in the space near the cylinder head portion 41 in the combustion chamber 4r formed between the piston portion 5 and the cylinder head portion 41.
  • the tumble flow (T1 to T3) is a flow that goes around a line R that intersects the central axis C.
  • a straight line Q obtained by extending the center line P of the intake passage 41a from the center 41c of the intake port 41b is the non-ignition part region F and the non-squish region N where the ignition part 7 is not disposed. Pass through. For this reason, the main part of the air-fuel mixture that has entered the combustion chamber 4r from the intake port 41b flows in the direction of the straight line Q extending the center line P of the intake passage 41a from the intake port 41b or a direction close to the direction of the straight line Q. That is, the tumble flow (T1 to T3) is generated in a direction substantially along a straight line Q extending from the center line P of the intake passage 41a from the intake port 41b.
  • the tumble flow (T1 to T3) does not go from the intake port 41b to the exhaust port 41f, but is inclined to the direction from the intake port 41b to the exhaust port 41f.
  • the tumble flow (T1 to T3) is generated in the direction passing through the non-ignition part region F from the center 41c of the intake port 41b.
  • the direction (T3) of the tumble flow in the vicinity of the ignition unit 7 is a component from the intake port 41b to the exhaust port 41f, that is, a component in the front-rear direction Y, and a component from the ignition unit 7 to the non-ignition part region F. That is, it includes a component in the width direction X.
  • the swirl flow of the air-fuel mixture is a flow that rotates around the central axis C.
  • Three arrows S1 to S3 in FIG. 8 schematically indicate the direction of the swirl flow.
  • a straight line Q obtained by extending the center line P of the intake passage 41a from the center 41c of the intake port 41b is the non-ignition part region F and the non-squish region N where the ignition part 7 is not disposed. Pass through.
  • the main part of the air-fuel mixture that has entered the combustion chamber 4r from the intake port 41b flows in the direction of the straight line Q extending the center line P of the intake passage 41a from the intake port 41b or a direction close to the direction of the straight line Q.
  • the swirl flow (S1 to S3) rotates around the central axis C in the direction passing through the intake port 41b, the exhaust port 41f, and the ignition unit 7 in this order (clockwise in FIG. 8).
  • the intake passage 41a is provided so as to form an arc that curves on the upstream side of the intake port 41b when viewed in the direction of the central axis C of the cylinder bore 42b.
  • the igniter 7 is provided outside the arc that curves when viewed in the direction of the central axis C of the cylinder bore 42b. For this reason, the swirl flow of the air-fuel mixture passing through the intake passage 41a is strengthened. Further, in this embodiment, when viewed in the direction of the central axis C, the straight line Q passes through the non-ignition part region F where the ignition part 7 is not disposed and does not overlap the exhaust port 41f. N extends. That is, the intake passage 41a is further inclined with respect to the exhaust port 41f as compared with a configuration in which, for example, the straight line Q overlaps with the exhaust port 41f. Thereby, the swirl flow of the air-fuel mixture passing through the intake passage 41a is further strengthened. For this reason, the swirl flow is easily maintained in the combustion chamber 4r.
  • the direction S3 of the swirl flow around the ignition unit 7 is substantially the same as the direction from the exhaust port 41f to the intake port 41b.
  • the combustion chamber 4r has a non-squish region N on at least a part of the outer periphery of the combustion chamber 4r in the radial direction of the cylinder bore 42b.
  • the non-squish region N is a region where at least the cylinder head portion of the cylinder head portion and the piston portion is not provided with a protruding portion for generating a squish effect.
  • the intake passage 41a When viewed in the direction of the central axis C, the intake passage 41a is provided such that the non-squish region N is arranged on a straight line Q extending from the center 41c of the intake port 41b to the center line P of the intake passage 41a. Yes.
  • the air-fuel mixture that has entered the combustion chamber 4r from the intake port 41b mainly occurs in a direction along a straight line Q extending the center line P of the intake passage 41a. For this reason, the flow of the air-fuel mixture entering the combustion chamber 4r from the intake port 41b is directed to the non-squish region N.
  • a recess 5 c is provided on the top surface 5 t of the piston portion 5.
  • the area where the recess 5c and the ignition part region E overlap is larger than the area where the recess 5c and the non-ignition part region F where no ignition part is provided.
  • a wide space constituting the combustion chamber 4r is secured around the ignition part 7 as shown in FIG.
  • the straight line Q extending from the center 41c of the intake port 41b passes through the non-ignition part region F in which the area overlapping with the recess 5c is small and the ignition part 7 is not disposed.
  • Combustion starts when the air-fuel mixture in the combustion chamber 4r is ignited by the ignition unit 7.
  • the flame generated by ignition tends to travel and spread along the flow of the air-fuel mixture itself.
  • the component in the same direction as the direction from the intake port 41b to the exhaust port 41f in the tumble flow T3 is attenuated by the swirl flow S3. Therefore, the flow of the air-fuel mixture around the ignition part 7 becomes gentle. For this reason, in the initial stage of combustion, it is possible to prevent the flame generated by ignition from proceeding rapidly toward the exhaust port 41f.
  • FIG. 9 is a schematic diagram showing the flow of air-fuel mixture in an engine in which a swirl flow does not substantially occur as a comparative example of the present embodiment.
  • the fluidity of the air-fuel mixture is likely to deteriorate in the entire combustion chamber. Further, when the squish region is provided, there is a possibility that the fuel in the air-fuel mixture tends to be unburned.
  • the engine 1 in the present embodiment it is possible to prevent the flame generated by the ignition from proceeding rapidly toward the exhaust port 41 f at the initial stage of combustion. Therefore, a rapid pressure increase in the initial stage of combustion is suppressed, and the generation of combustion noise is suppressed. For this reason, even if, for example, a ball bearing with low support rigidity is adopted as the bearing 31 that supports the crankshaft 2, combustion noise is suppressed. Further, in the engine 1, as shown by an arrow U in FIG. 8, the air-fuel mixture around the ignition unit 7 is changed from the ignition unit region E where the ignition unit 7 is arranged to the non-ignition unit region where the ignition unit 7 is not arranged.
  • the flame generated in the ignition unit 7 tends to spread quickly from the periphery of the ignition unit 7 to the entire combustion chamber 4r. Therefore, the time for the flame to spread in the main region of the combustion chamber 4r is shortened. That is, the main combustion period in the expansion stroke is shortened.
  • FIG. 10 is a graph for explaining the combustion state of the air-fuel mixture in the engine.
  • the vertical axis of the graph of FIG. 10 is the heat generation rate dQ / d ⁇ , and the horizontal axis is the rotation angle ⁇ of the crankshaft 2.
  • H1 schematically shows the characteristics of the heat generation rate in the engine 1
  • H9 schematically shows the characteristics of the heat generation rate in the comparative example shown in FIG.
  • the main combustion period J is expressed as a crank angle from the time when 10% of the heat generated in one cycle is generated to the time when 90% of the generated heat is generated. According to the engine 1 of the present embodiment, it is possible to suppress the rapid progress of the flame toward the exhaust port at the initial stage of combustion. For this reason, compared with the case of the heat generation rate H9 of the comparative example, the peak value of the heat generation rate H1 is suppressed, and the rate of increase of the heat generation rate H1 is suppressed. Furthermore, according to the engine 1 of the present embodiment, the main combustion period J is shortened because the flame tends to spread quickly from the periphery of the ignition unit 7 to the entire combustion chamber 4r. Therefore, fuel consumption is improved. Thus, according to the engine 1 of the present embodiment, it is possible to suppress the generation of combustion noise while improving fuel efficiency.
  • the intake passage 41a is provided so as to form an arc that curves on the upstream side of the intake port 41b when viewed in the direction of the central axis C of the cylinder bore 42b.
  • the ignition part 7 is provided in the outer side of the curved arc.
  • the recess 5c ensures a wide space that constitutes the combustion chamber 4r around the ignition unit 7 even when the piston unit 5 moves to near the top dead center. For this reason, even when the piston part 5 moves to the top dead center, the swirl flow of the air-fuel mixture around the ignition part 7 is easily maintained. Further, the situation where the air-fuel mixture around the ignition part 7 is cooled by the piston part 5 is suppressed. In addition, since the bottom of the combustion chamber 4r is expanded spherically by the spherical recess 5c, the swirl flow of the air-fuel mixture in the combustion chamber is more easily maintained. Therefore, it is possible to further suppress the generation of combustion noise while further improving the fuel consumption.
  • a part of the space of the combustion chamber 4r is narrowed by the convex portion 5p provided on the top surface 5t of the piston portion 5.
  • the space narrowed by the convex portion 5p is a space that overlaps the convex portion 5p when viewed in the direction of the central axis of the cylinder bore, and is a space in the non-ignition portion region F that is separated from the ignition portion 7. In the space away from the ignition unit 7, the unburned state of the air-fuel mixture tends to occur.
  • a straight line Q extending the center line P of the intake passage 41a passes through the non-ignition part region F where the ignition part 7 is not disposed, and the exhaust port
  • the example which extends without overlapping with 41f was demonstrated.
  • the present invention is not limited to this.
  • a straight line obtained by extending the center line of the intake passage may extend so as to overlap the exhaust port.
  • the example in which the convex part 5p was provided in the top surface 5t of the piston part 5 was demonstrated.
  • the present invention is not limited to this.
  • the top surface of the piston portion does not have to be provided with a convex portion.
  • the concave portion 5c provided on the top surface 5t of the piston portion 5 has a spherical shape.
  • the present invention is not limited to this.
  • the concave portion may have a flat bottom surface.
  • the recessed part does not need to be provided in the top surface of the piston part.
  • the intake passage 41a is provided so as to form an arc that curves on the upstream side of the intake port 41b when viewed in the direction of the central axis C of the cylinder bore 42b.
  • the present invention is not limited to this. For example, it may extend linearly on the upstream side of the intake port 41b.
  • the example of the engine 1 including one cylinder bore 42b, one intake valve 8a, and one exhaust valve 8b has been described.
  • the present invention is not limited to this.
  • the two-valve engine of the present invention includes only two valves for one cylinder bore.
  • the number of cylinders of the two-valve engine of the present invention is not particularly limited.
  • the two-valve engine of the present invention may be, for example, a two-valve engine that has two cylinder bores and is provided with only two valves for each of the two cylinder bores.
  • An example of such an engine is a V-type 2-cylinder engine.
  • a V-type two-cylinder engine can be assembled by inserting a bearing into a hole formed in, for example, a crankcase portion. That is, it is not necessary to divide the crankcase portion at the position of the hole for inserting the bearing. Therefore, the V-type 2-cylinder engine is suitable for a rolling bearing.
  • the engine of the present invention may have, for example, a roller bearing as a journal bearing for the crankshaft.
  • the engine of this invention may have a sliding bearing, for example.
  • the present invention is not limited to the above-described example, and for example, the following configuration (6) or (7) can be adopted. Examples of the following (6) or (7) include the above-described embodiments.
  • the two-valve engine when viewed in the direction of the central axis of the cylinder bore, is defined by two regions defined by dividing the recess by a straight line extending the center line of the intake passage from the center of the intake port. A region having a large area is provided so as to overlap the ignition portion.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)

Abstract

La présente invention concerne un moteur à deux soupapes dans lequel l'économie de carburant peut être améliorée tout en supprimant également le bruit de combustion. Ce moteur à deux soupapes comprend : un vilebrequin ; un palier à roulement ; une partie de piston ; une partie de cylindre comprenant une culasse de cylindre qui comporte un orifice d'admission et un orifice d'échappement, et un corps de cylindre qui comporte un alésage de cylindre, ladite partie de cylindre formant une chambre de combustion conjointement avec la partie de piston ; une partie d'injection de carburant ; et une partie d'allumage prévue sur une zone parmi deux zones définies en divisant la chambre de combustion au moyen d'une ligne droite passant à travers le centre de l'orifice d'admission et le centre de l'orifice d'échappement. La partie de piston comporte un évidement dans une face supérieure de celle-ci. La superficie où l'évidement chevauche une zone où la partie d'allumage n'est pas fournie est plus petite que la superficie où l'évidement chevauche une zone où la partie d'allumage est fournie. Un passage d'admission est fourni de telle sorte qu'une zone dans laquelle la partie d'allumage n'est pas disposée et qui a une petite superficie de chevauchement avec l'évidement est placée au-dessus d'une ligne droite qui est une extension de l'axe central du passage d'admission à partir du centre de l'orifice d'admission.
PCT/JP2015/063565 2015-05-12 2015-05-12 Moteur à deux soupapes WO2016181483A1 (fr)

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EP15891808.6A EP3296551B1 (fr) 2015-05-12 2015-05-12 Moteur à deux soupapes
PCT/JP2015/063565 WO2016181483A1 (fr) 2015-05-12 2015-05-12 Moteur à deux soupapes

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58154823U (ja) * 1982-04-09 1983-10-17 日産自動車株式会社 内燃機関の燃焼室形状
JPH1150907A (ja) * 1997-08-01 1999-02-23 Honda Motor Co Ltd 内燃機関のピストン
JP2004278634A (ja) * 2003-03-14 2004-10-07 Honda Motor Co Ltd 自動二輪車のクランクシャフト支持軸受における打音防止構造
JP2007146815A (ja) * 2005-11-30 2007-06-14 Honda Motor Co Ltd 内燃機関
JP2015001154A (ja) * 2013-06-13 2015-01-05 本田技研工業株式会社 内燃機関のクランクシャフト軸受構造
JP2015063926A (ja) * 2013-09-25 2015-04-09 本田技研工業株式会社 内燃機関の燃焼室構造

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1184314A (fr) * 1957-10-14 1959-07-20 Moteur à combustion interne avec piston et culasse à surfaces galbées
JPS54145808A (en) * 1978-05-04 1979-11-14 Nissan Motor Co Ltd Reciprocating spark ignition internal combustion engine
JPS5820369B2 (ja) * 1978-07-20 1983-04-22 トヨタ自動車株式会社 内燃機関の燃焼室構造
AT400740B (de) * 1986-12-19 1996-03-25 Avl Verbrennungskraft Messtech Hubkolben-viertakt-brennkraftmaschine
JP2815592B2 (ja) * 1988-11-29 1998-10-27 マツダ株式会社 エンジンの燃焼室
SE519767C2 (sv) * 1997-11-26 2003-04-08 Volvo Car Corp Förbränningssystem
US8997724B2 (en) * 2013-02-25 2015-04-07 Kubota Corporation Spark-ignition engine

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58154823U (ja) * 1982-04-09 1983-10-17 日産自動車株式会社 内燃機関の燃焼室形状
JPH1150907A (ja) * 1997-08-01 1999-02-23 Honda Motor Co Ltd 内燃機関のピストン
JP2004278634A (ja) * 2003-03-14 2004-10-07 Honda Motor Co Ltd 自動二輪車のクランクシャフト支持軸受における打音防止構造
JP2007146815A (ja) * 2005-11-30 2007-06-14 Honda Motor Co Ltd 内燃機関
JP2015001154A (ja) * 2013-06-13 2015-01-05 本田技研工業株式会社 内燃機関のクランクシャフト軸受構造
JP2015063926A (ja) * 2013-09-25 2015-04-09 本田技研工業株式会社 内燃機関の燃焼室構造

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3296551A4 *

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EP3296551A4 (fr) 2018-03-21
EP3296551B1 (fr) 2020-10-21
EP3296551A1 (fr) 2018-03-21

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