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US 8,573,166 B2Granted
Spark ignition type internal combustion engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsYukihiro Nakasaka, Yoshihiro Sakayanagi, Hiroyuki Tanaka
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AssigneeToyota Jidosha Kabushiki Kaisha
InventorsYukihiro Nakasaka, Yoshihiro Sakayanagi, Hiroyuki Tanaka
Estimating the term…
An internal combustion engine which is provided with a variable compression ratio mechanism which can change a mechanical compression ratio and a variable valve timing mechanism which can control a closing timing of an intake valve. No-entry regions (X1, X2) are set for a combination of the mechanical compression ratio, the closing timing of the intake valve, and the intake air amount. Furthermore, a no-entry layer is set so as to surround the no-entry region (X2). When the demanded intake air amount is made to decrease and the operating point moves toward the no-entry region (X2), the operating point is prohibited from entering the no-entry layer whereby the operating point is blocked from entering the no-entry region (X2).
A spark ignition type internal combustion engine comprising a variable compression ratio mechanism which can change a mechanical compression ratio and a variable valve timing mechanism which can control a closing timing of an intake valve, wherein a no-entry region for a combination of a mechanical compression ratio, a closing timing of an intake valve and an intake air amount is set, an operating point showing the combination of the mechanical compression ratio, the closing timing of the intake valve and the intake air amount is prohibited from entering the no-entry region regardless of an operating state of the engine, the no-entry region has a broadest region at the time of a minimum intake air amount and gradually becomes smaller as the intake air amount increases, a no-entry layer is set which extends along an edge of the no-entry region at the time of the minimum intake air amount and which extends from the no-entry region toward an intake air amount increase side while surrounding the no-entry region as the intake air amount increases from the minimum intake air amount, said operating point is prohibited from entering the no-entry layer when the demanded intake air amount is made to decrease and said operating point moves toward the no-entry region, and thereby said operating point is blocked from entering the no-entry region.
Dependencies are inferred from the claim text.
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Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing: during engine operation
Varying compression ratio: by alteration of volume of compression space without changing piston stroke
Internal combustion engine [ICE] based vehicles: improving ICE efficiencies
Controlling combustion engines
About 3 years 3 months of term left · ends 28 Jan 2030 (estimated)
This is a 371 national phase application of PCT/JP2010/051543 filed 28 Jan. 2010, the contents of which are incorporated herein by reference.
The present invention relates to a spark ignition type internal combustion engine.
Known in the art is a spark ignition type internal combustion engine which is provided with a variable compression ratio mechanism which can change the mechanical compression ratio and a variable valve timing mechanism which can control a closing timing of an intake valve and which is designed to maintain an actual compression ratio substantially constant regardless of an engine load (see, for example, Patent Literature 1). In this internal combustion engine, as the engine load becomes higher, that is, as the demanded intake air amount becomes greater, the closing timing of the intake valve is advanced to approach intake bottom dead center. At this time, to maintain the actual compression ratio substantially constant, the mechanical compression ratio is made to drop as the demanded intake air amount becomes greater.
FIG. 1 is an overview of a spark ignition type internal combustion engine.
FIG. 2 is a disassembled perspective view of a variable compression ratio mechanism.
FIG. 3 is a side cross-sectional view of an internal combustion engine expressed schematically.
FIG. 1 is a side cross-sectional view of a spark ignition type internal combustion engine.
Referring to FIG. 1, 1 indicates a crankcase, 2 a cylinder block, 3 a cylinder head, 4 a piston, 5 a combustion chamber, 6 a spark plug which is arranged at a center of a top face of a combustion chamber 5, 7 an intake valve, 8 an intake port, 9 an exhaust valve, and 10 an exhaust port. Each intake port 8 is connected through an intake branch pipe 11 to a surge tank 12. At each intake branch pipe 11, a fuel injector 13 which injects fuel toward the corresponding intake port 8 is arranged. Note that, the fuel injectors 13 may also be arranged inside the combustion chambers 5 instead of being attached to the intake branch pipes 11.
The surge tank 12 is connected through an intake duct 14 to an air cleaner 15. Inside of the intake duct 14, a throttle valve 17 which is driven by an actuator 16 and an intake air amount detector 18 which uses for example a hot wire are arranged. On the other hand, each exhaust port 10 is connected through an exhaust manifold 19 to a catalytic converter 20 which holds a for example three-way catalyst. Inside the exhaust manifold 19, an air-fuel ratio sensor 21 is arranged.