Mazda Motor Corporation

Toyo Kogyo Co., Ltd.

Toyo Kogo Co., Ltd.

Toshihiko Hattori

Mitsuo Hitomi

Junsou Sasaki

Kenji Kashiyama

Shunji Masuda

Mikihito Fujii

Naoyuki Yamagata

Masashi Marubara

Toshimitsu Tanaka

Noriyuki Iwata

Yasuhiro Yuzuriha

Akinori Yamashita

Hideo Kohara

Yuji Akagi

Hiroyuki Oda

Kazuhiko Ueda

Tadayoshi Kaide

Kouji Tarumoto

Tuyoshi Morishita

Toshio Yamada

Kazumasa Nomura

Yashuhumi Kawado

Kazuaki Umezawa

Seiichi Kakuwa

Ichiro Yamagata

An internal combustion engine with a supercharger with a piston arranged to be inserted into a cylinder so as to move in a reciprocating way, which has a bore size of the cylinder ranging from approximately 43 mm to 67 mm; a volume of a single chamber of the cylinder ranging from approximately 110 cc to 400 cc; a ratio of a stroke of the piston to the bore size of the cylinder being larger than 1; and a compression ratio of the engine being 9 or larger.

Internal combustion engine with supercharger

A spark ignition type reciprocating engine of a natural intake system with an ignition plug arranged to face a combustion chamber defined and delimited by a piston inserted into a cylinder so as to move in a reciprocating way, which has:

Reciprocating engine of a spark ignition type

An internal combustion engine of a spark ignition type is so arranged as to set an air-fuel ratio of a mixed fuel to become substantially stoichiometric in the range of from A/F=13 to A/F=16 at the time of running in a high load region and to recirculate exhaust gases into the intake system. For the internal combustion engine of a natural intake type, the compression ratio is preferably set to 11 or larger; for the internal combustion engine of a supercharging type, the compression ratio is preferably set to 9 or larger. The rate at which the exhaust gases are recirculated is preferably set to be constant or to become larger as the load of the engine becomes larger.

Engine of a spark ignition type

The supercharged internal combustion engine is so adapted as to set the air-fuel ratio to become a lean air-fuel ratio which is leaner than stoichiometric and lean enough to maximize improvements in a rate of consumption of fuel, for example, to the A/F ratio of 16, when the supercharger exists in such a supercharging region as demonstrating its sufficient degree of supercharging capability. When the air-fuel ratio is made lean in the supercharging region, exhaust gases are recirculated into the intake system of the engine, in addition to a mixed fuel. Preferably, the exhaust gases having lower temperatures are recirculated at the time of a high load of the engine in the supercharging region, while the exhaust gases having higher temperatures are recirculated at the time of a low load of the engine therein.

Supercharged internal combustion engine

Disclosed is an exhaust gas recirculation system for an engine having a high compression ratio or with a supercharger. An outside EGR duct connecting the exhaust system to the intake system is provided with a first control valve, which has a second outside EGR duct bypassing the first control valve. The second EGR duct has a second EGR control valve and a cooler. When the engine exists in an extremely low load state, the first and second control valves are closed to inhibit the outside EGR. In the light load state, the first control valve is opened while the second control valve is closed, thereby allowing recirculation of the EGR gases having high temperature and reducing the pumping loss. In the high load state, the first control valve is being closed while opening the second control valve, thereby increasing a recirculation ratio of EGR gases cooled by the cooler and performing both an improvement of anti-knocking performance and a decrease in pumping loss, as well as reducing the heat load of the exhaust system and within the engine.

Exhaust gas recirculation system for an internal combustion engine

The engine is provided with an auxiliary chamber having an auxiliary chamber port with an opening communicated with the combustion chamber. The auxiliary chamber port is arranged to be opened or closed with an auxiliary chamber valve. The timing of closing the auxiliary chamber valve is in between a final stage of compression stroke in which the temperature within the cylinder becomes higher and an initial stage of explosion stroke. On the other hand, the timing of opening the auxiliary chamber valve is in a middle stage of the compression stroke, thereby allowing the mixed fuel cooled in the auxiliary chamber to be replaced with a portion of the mixed fuel in the combustion chamber, thereby lowering the temperature within the cylinder.

Internal combustion engine

An intake system for a vehicle for delivering intake air through separate or discrete intake passages of the intake system into engine cylinders through discrete intake passages. A collector chamber and a resonator chamber connect with an upstream main intake passage and the discrete intake passages. The collector chamber communicates at one end with upstream ends of the discrete intake passages and at its another end, opposite to the one end, with the resonator chamber. The discrete intake passages are clustered or grouped together at their upstream ends and connected as a cluster to the collector chamber.

Intake system for multi-cylinder engine

An intake manifold for a multi cylinder internal combustion engine has a common upstream passage and individual downstream passages, leading individually to cylinders of the engine, respectively. These individual downstream passages are connected between a downstream end of the common upstream passage and the cylinders. Upstream end portions of the individual downstream passages are symmetrically located around a fuel injector, disposed downstream relative to the common upstream passage, and are joined together. At a center of the symmetrically joined upstream end portions of the individual downstream passages, fuel passages are provided to open independently into the upstream end portions so as to introduce fuel from the fuel injector into the individual downstream passages.

Intake manifold of intake system for multi-cylinder internal combustion

Discrete intake passages communicating with respective cylinders of a multiple-cylinder in-line engine are merged into an integrated chamber at their upstream ends. The integrated chamber is disposed above the engine and extends substantially horizontally. Each discrete intake passage extends from the engine body, bends upward toward the integrated chamber and is connected to the downstream side end face of the integrated chamber. The discrete intake passages for the cylinders which are positioned relatively near to the integrated chamber are connected to the downstream side end face of the integrated chamber at an upper portion of the end face and the discrete intake passages for the cylinders which are positioned relatively far from the integrated chamber are connected to the downstream side end face of the integrated chamber at a lower portion of the end face.

Intake system for engine

An engine has a plurality of cylinders and the cylinders are divided into first and second cylinder groups so that the cylinders in each cylinder group do not fire one after another. An intake system for the engine has a plurality of discrete intake passages extending from the respective cylinders of the engine and merge into a junction chamber, a common intake passage which opens to the atmosphere at its upstream end and communicates with the junction chamber at its downstream end, a first communicating passage which is connected to the discrete intake passages for the first cylinder group at their intermediate portions and communicates them with each other, and a second communicating passage which is connected to the discrete intake passages for the second cylinder group at their intermeidate portions and communicates them with each other.

Plural cylinders are grouped, for example, into two cylinder groups composed of plural cylinders having each inspiration stroke in an equal distance, and each of the grouped cylinder groups is communicated with a volume chamber. To this volume chamber is connected each of the independent air intake passages extending independently or separately from each of the corresponding cylinder. A first connecting portion is disposed to communicate the individual air intake passages for each of the cylinder groups with each other in a position spaced apart in an equal distance from an intake port. Further, a second connecting portion as a resonant passage is disposed to communicate one first connecting portion with the other connecting portion for each cylinder group.

Plural cylinders are divided into cylinder groups consisting of the cylinders each having an equal inspiration stroke. The cylinder groups are so disposed as to allow their inspiration strokes to be apart from each other in a direction parallel to a crank axis in which a crankshaft extends. On its side surface, the cylinder head has an opening for an intake port which is communicated with an individual intake passage. Each of plural individual intake passage is extended from the respective cylinders for each cylinder group in the direction extending or elongated over the cylinder head and merged together at that location into a merged intake passage. The merged intake passage is extended toward the intermediate position between the two cylinder groups and thereafter curved, followed by extending toward the side of one side surface of the cylinder head.

Intake piping structure for multi-cylinder engine

A multiple-cylinder engine has first and second groups of cylinders, the firing order being set so that the cylinders in each group do not fire one after another. An intake system for the engine has first and second groups of discrete intake passages which communicate with the respective cylinders in the first and second groups at their downstream ends and with first and second branch intake passage at their upstream ends. A circular passage communicates with the discrete intake passages at their intermediate portions so that all the discrete intake passages communicate with each other through the circular passage, and an on-off valve opens the circular passage when the engine speed is higher than a predetermined value and closes the same when the engine speed is not higher than the predetermined value. The length of each discrete intake passage is such that a first inertia tuning is obtained at a first engine speed lower than a maximum allowable engine so long as the discrete intake passages are not communicated with the circular passage, and the length of the part of each discrete intake passage downstream of the circular passage is such that a second inertia tuning is obtained at a second engine speed higher than the maximum allowable engine so long as the discrete intake passages are communicated with the circular passage.

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Hiroshima, Japan

Toshihiko Hattori