Mazda Motor Corporation

Matsushita Electric Industrial Co., Ltd.

Noriyuki Iwata

Naoyuki Yamagata

Tatsuya Uesugi

Mitsuo Hitomi

Shunji Masuda

Kenji Kashiyama

Osamu Sado

Junsou Sasaki

Toshiaki Nishimoto

Takayoshi Hayashi

Kazumasa Nomura

Takashi Yohso

Masahisa Yamakawa

Toshihiko Hattori

Kazuhiko Ueda

Kazuhiko Hashimoto

Keiji Araki

Tatsuya Fujikawa

Junichi Okita

Kouichi Hatamura

Ichiro Hirose

Toshimitsu Tanaka

Taketoshi Yamauchi

Ryoji Abe

Kouji Asanomi

Yoshiyuki Shinya

Kouji Sumida

Tadayoshi Kaide

Hidefumi Fujimoto

Taiji Matsubara

Masahiro Choshi

Toru Shiraishi

Tomohisa Handa

Shigeyuki Hirashita

Kouichi Hashiyama

Kazuaki Umezawa

Kazuki Makimura

A spark-ignition gasoline engine having at least a spark plug, the engine including an engine body having a geometrical compression ratio set at 14 or more, and an intake valve and an exhaust valve provided, respectively, in intake and exhaust ports connected to each of a plurality of cylinders of the engine body. The intake and exhaust valves are adapted to open and close corresponding respective ones of the intake and exhaust ports. The engine further includes an operation-state detector adapted to detect an operation state of the engine body and a control system adapted, based on detection of the operation-state detector, to perform at least an adjustment control of an ignition timing of the spark plug, the control system being operable, when an engine operation zone is a high-load operation zone including a wide open throttle region within at least a low speed range, to retard the ignition timing to a point within a predetermined stroke range just after a top dead center of a compression stroke.

Spark-ignition gasoline engine

Disclosed is a spark-ignition gasoline engine, which comprises control means operable, when an engine operation zone is a high-load operation zone including a WOT region within at least a low speed range, to adjust a closing timing of an intake valve in such a manner as to maintain an effective compression ratio at 13 or more, and retard an ignition timing to a point within a predetermined stroke range just after a top dead center of a compression stroke, wherein the effective compression ratio is calculated based on an intake-valve closing timing defined by a valve lift amount of 1 mm. The present invention can provide a spark-ignition gasoline engine having both a low-cost performance and a high engine-power performance even in a high-load operation zone (particularly WOT region) in a low speed range.

For the purpose of improving the fuel efficiency by lean combustion and enhancing the fuel efficiency improvement effects by performing compression ignition efficiently in some cylinders, a multi-cylinder spark ignition engine is constructed such that exhaust gas, that is exhausted from preceding cylindersA,D on the exhaust stroke side among pairs of cylinders whose exhaust stroke and intake stroke overlap in a low load, low rotational speed region, is directly introduced through an inter-cylinder gas passageinto following cylindersB,C on the intake stroke side and only gas exhausted from the following cylindersB,C is fed to an exhaust passage, which is provided with a three-way catalyst. Combustion controller is provided that controls the combustion of each of the cylinders such that combustion is conducted by forced ignition in a condition in which the air/fuel ratio is a lean air/fuel ratio which is larger by a prescribed amount than the stoichiometric air/fuel ratio in the preceding cylindersA,D and, in the following cylindersB,C, fuel is supplied to burnt gas of lean air/fuel ratio introduced from the preceding cylindersA,D and combustion is conducted by compression ignition.

Spark ignition engine control device

A throttle device is arranged in the midstream of an individual passage consisting of a low-speed individual intake passage and a high-speed individual intake passage on the downstream of a surge tank. A valve body is rotatably provided in the throttle valve device. The inside of the valve body is formed with an in-valve low-speed passage and an in-valve high-speed passage that are adjacently placed with respect to the rotational axis of the valve body. The intake air supply is performed through only the low-speed individual passage when the opening of the valve body is equal to or less than a predetermined value, and through both the low-speed individual intake passage and high-speed individual intake passage when the opening of the body is larger than the predetermined value.

Air intake system for multi-cylinder engine

V-type engine has intake and exhaust valves for each cylinder, the intake valve being inclined at an angle relative to a center line of each cylinder bore larger than an angle relative to the center line at which the exhaust valve is inclined, and having a length between an intake valve face and an intake cam longer than a length between an exhaust valve face and an exhaust cam of the exhaust valve.

V-type engine

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

A cam shaft support device for an engine includes a cam carrier. A plurality of bearings are integrally formed with the cam carrier so as to rotatively support two cam shafts installed on a cylinder head. Each of the bearings are provided with a slit on a lower portion thereof so as to reduce the sliding resistance between the bearings and the cam shafts.

Cam shaft support apparatus for an engine

An apparatus for driving devices which are operated by, or 'supplementary' to, a V-type internal combustion engine, having a crankshaft and overhead camshafts, includes a camshaft drive mechanism for rotatably connecting the camshafts to the crankshaft so that the camshafts are 'timely' driven. A supplementary device drive mechanism rotatably connects supplementary devices independently of the overhead camshafts to the crankshaft. The crankshaft is provided with a transmission gear train for transmitting rotation of the camshafts to the camshaft drive mechanism and the supplementary device drive mechanism.

Apparatus for driving various devices by internal combustion engine

The support structure for cam shafts including an intake cam shaft and an exhaust cam shaft, a pair of intake cams per a cylinder formed side by side on the intake cam shaft, a pair of exhaust cams per a cylinder formed side by side on the exhaust cam shaft and having longer interval therebetween than that of the intake cams, a cam cap forming an upper portion of the support structure for the cam shafts and an upper wall portion of a plug hole for inserting the ignition plug, a cam carrier forming a lower portion of the support structure for the cam shafts and a lower wall portion of the plug hole, and fasteners for fastening the cam cap to an engine block. The fasteners are disposed both at longitudinally opposite sides of the pair of intake cams and between the pair of the exhaust cams.

Support structure for cam shafts

An engine with a row of cylinders is provided with two intake ports and intake valves and two exhaust ports and exhaust valves for each cylinder. The intake ports are arranged on one side of a center line of the row of cylinders, adjacent to each other, and side by side in a direction parallel to the cylinder row. The exhaust ports are arranged on another side of the center line, adjacent to each other, and side by side in the direction parallel to the cylinder row so that their centers are located at a distance apart which is larger than a distance at which centers of the intake ports are separated. The cylinder is formed with a 'squish' surface between the exhaust ports which provides a squish area between the cylinder head and piston. This produces a squish or compressed flow of the air-fuel mixture to the exhaust ports in the combustion chamber.

Cylinder head structure of an internal combustion engine

An exhaust gas recirculation system of an engine equipped with a supercharger has an exhaust gas circulation passage for circulating exhaust gas into an intake system from an exhaust system, and a return passage for returning exhaust gas introduced into the exhaust gas circulation passage to the exhaust system. The exhaust gas circulation passage is made available to the exhaust gas when the engine operates within a specified area of engine operating conditions in which supercharging is to be effected. The return passage is made available to the exhaust gas when the engine operates within an area, other than the specified area, of engine operating conditions.

Exhaust gas recirculation system

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

A valve driving mechanism for a double overhead camshaft engine includes a camshaft drive mechanism, including a camshaft sprocket for transmitting engine output from a crankshaft of the engine to one of intake and exhaust camshafts. A valve timing varying mechanism is driven so as to vary a valve timing of, for example, a set of intake valves relative to a valve timing of a set of exhaust valves. The valve timing varying mechanism includes a first helical gear, mounted on the exhaust camshaft for rotation, a second helical gear, in mesh with the first helical gear, which is rigidly secured to the intake camshaft, and a cylindrical sliding element, mounted on the exhaust camshaft for axial displacement. The cylindrical sliding element operationally couples the exhaust camshaft to the camshaft drive mechanism so as to cause a relative rotational displacement therebetween when the cylindrical sliding element undergoes axial displacement with respect to the exhaust camshaft.

Valve driving mechanism for double overhead camshaft engine

A multi-valve internal combustion engine has a plurality of intake valves, and the same number of intake ports as there are intake valves, for each engine cylinder. One of the intake ports forms a helical passage, opening into a center of a combustion chamber of the engine at the location of a spark plug, which is disposed adjacent an intake valve located in the center intake port. In addition to a fuel injector disposed in one of the intake ports, a secondary fuel injector, energized so as to inject fuel when the engine operates at lower loads, is preferably disposed adjacent the intake valve located in the one intake port.

Multi-valve internal combustion engine

A cylinder head for a double overhead camshaft engine, with a plurality of intake valves and a plurality of exhaust valves for each cylinder, is covered by a cylinder head cover to support, for rotation, intake and exhaust camshafts. A hermetically sealed chamber, formed between the cylinder head and head cover as an oil jacket, is divided into two chambers, enclosing major parts of the intake and exhaust camshafts, respectively, which are in communication with each other near first ends of the chambers. An outlet hole is formed in the cylinder head cover so as to permit blow-by gas to flow out of the chamber. A cover, covering a gear train for operationally coupling the intake and exhaust camshafts, is bolted to one end of the head cover at several points around the gear train and to the cylinder head.

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Hiroshima, Japan

Noriyuki Iwata