Mazda Motor Corporation

Mazda Motor Corporat Ion

Toshiaki Nishimoto

Masahisa Yamakawa

Mitsuo Hitomi

Takashi Youso

Keiji Araki

Masanori Hashimoto

Takayoshi Hayashi

Tatsuya Fujikawa

Kouji Asanomi

Noriyuki Iwata

Kouji Shishime

Taketoshi Yamauchi

Hisashi Okazawa

Junsou Sasaki

Takafumi Nishio

Hirokazu Matsuura

Takahiro Yamamoto

Kouji Sumida

Naoya Watanabe

Hiroaki Abe

Takashi Yohso

Kazuhiro Nagatsu

Tomomi Watanabe

Yasushi Nakahara

Hiroki Morimoto

Naohiro Yamaguchi

Hiroshi Takahashi

Yoshiyuki Shinya

Masatoshi Hidaka

Akira Tsuda

Naoya Matsuo

Yohei Suzuki

Mikinori Ohashi

Takaya Okugawa

Kiyotaka Sato

Yoshiteru Nakayama

A control device for an engineincluding cylinders, and configured to perform a reduced-cylinder operation by idling some of cylinders. The control device includes a hydraulic valve-stopping mechanismwhich closes the intake and exhaust valvesof the cylinders in response to establishment of the reduced-cylinder operation execution condition, a hydraulic variable valve timing mechanismcapable of changing a phase of the exhaust valveof the engine, and an ECUwhich controls the valve-stopping mechanismand the hydraulic variable valve timing mechanism. In response to establishment of the reduced-cylinder operation execution condition, the ECUallows the hydraulic variable valve timing mechanismto execute the phase change to the exhaust valve, and subsequently allows the valve-stopping mechanismto bring the intake and exhaust valvesof the cylinders into closed state.

Control device for engine

A controller increases an actual oil pressure up to a transient oil pressure (an actuating oil pressure) and then supplies oil adjusted to have the transient oil pressure (the actuating oil pressure) to valve stopping mechanisms to actuate the valve stopping mechanisms. The controller, when actuating the valve stopping mechanisms, starts increase in an intake filling amount when the actual oil pressure increases up to a predetermined determination value set at the transient oil pressure (the actuating oil pressure) or lower.

Device and method for controlling engine

The number of advance chambers is larger than the number of retard chambers in an intake variable valve timing (VVT), whereas the number of retard chambers is larger than the number of advance chambers in an exhaust VVT. Accordingly, with limitation of an oil pressure that can be used by the VVTs, a pumping loss in a transition period in which a valve overlap amount is changed by advancing or retarding a valve timing can be reduced.

Engine with variable valve timing mechanism

A hydraulic control system for an engine having a plurality of cylinders includes: valve stop mechanisms that switch the engine from all-cylinder operation to cylinder cut-off operation; a VVT that can change the timing to open and close valvesduring all-cylinder operation and cylinder cut-off operation; an oil pump that supplies oil to hydraulically operated devices including the valve stop mechanisms and the VVT through a hydraulic path; and a control device. The control device controls a maintaining oil pressure, which is required to maintain the operated state of the valve stop mechanisms during cylinder cut-off operation, so that the maintaining oil pressure is set to a high value in a high oil viscosity region.

Hydraulic control system for engine

A hydraulic supply device for a valve stopping mechanism includes: a specific hydraulic oil supply passage which constantly supplies hydraulic oil, a valve stopping mechanism incorporated in a cylinder head, and configured to stop at least one of an intake valve and an exhaust valve, a valve stopping oil passage which supplies hydraulic oil to the valve stopping mechanism, a control valve which controls the supply of hydraulic oil to the valve stopping oil passage, and a communication oil passage which communicates between the valve stopping oil passage and the specific hydraulic oil supply passage, and provided with a restrictor therebetween. The specific hydraulic oil supply passage is connected to an oil supply portion for a portion to be lubricated or for a portion to be cooled in the engine at a position downstream of a connection position with respect to the communication oil passage in an oil supply direction.

Hydraulic supply device for valve stopping mechanism

The invention relates to a control device for a multi-cylinder engine provided with an oil pump, a hydraulically operated valve characteristic control device which changes valve characteristics of at least one of an intake valve and an exhaust valve; and a hydraulically operated valve stop device which stops at least one of the intake valve and the exhaust valve when a reduced cylinder operation is performed. The control device for a multi-cylinder engine is provided with a valve control unit which operates the valve stop device after an operation of the valve characteristic control device is completed when the valve characteristic control device is operated at a time of request for the reduced cylinder operation.

Control device for multi-cylinder engine

A control device of a multi-cylinder engine is provided. The device includes first and second auxiliary components. The first auxiliary component generates energy. The device includes an angular speed variation detecting device for detecting an angular speed variation of a crankshaft, and an auxiliary component control device for controlling drive loads of the first and second auxiliary components. When an engine load is low and the angular speed variation exceeds a predetermined threshold, the auxiliary component control device increases a total drive load of the auxiliary components. Here, if the drive load of the first auxiliary component is increasable, the drive load of the first auxiliary component is increased, and when this increase amount is insufficient, the drive load of the second auxiliary component is increased, whereas if the drive load of the first auxiliary component is not increasable, the drive load of the second auxiliary component is increased.

Method and device for controlling multi-cylinder engine

A control device of a multi-cylinder engine is provided. The control device includes an auxiliary component and a valve stopping device having a locking mechanism for stopping an operation of at least one of intake and exhaust valves of a specific cylinder of the multi-cylinder engine according to an engine operating state. The control device includes an angular speed variation detecting device for detecting an angular speed variation of a crankshaft, an auxiliary component control device for controlling a drive load of the auxiliary component. In an all-cylinder operation, when an engine load is lower than a predetermined value and the detected angular speed variation exceeds a predetermined threshold, the auxiliary component control device performs an auxiliary component drive load increase control in which the drive load of the auxiliary component is increased to reduce the angular speed variation to be lower than the predetermined threshold.

Control device of multi-cylinder engine

Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine, and a supercharger which supercharges air into the combustion chamber. One example method comprises, injecting fuel into the combustion chamber multiple times so that a first part of the fuel is self ignited and a last part of the fuel being injected during the compression stroke or later in a cylinder cycle when a desired torque of said internal combustion engine system is in a first range; and increasing a pressure of air which the supercharger charges into the combustion chamber as amount of fuel injected into the combustion chamber during a cylinder cycle increases when the desired torque is in the first range.

Supercharged direct fuel injection engine

Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, and a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine. One example method comprises, when a desired torque for the internal combustion engine system is in a first range, injecting a first stage fuel into the combustion chamber so that it ends during a middle stage of a compression stroke at the latest in a cylinder cycle; determining combustion of the first stage fuel initiated by its compression self-ignition; and injecting a second stage fuel into the combustion chamber in a period when the determined combustion of the first stage fuel continues at a timing determined so as to cause combustion of the second stage fuel with its compression self-ignition.

Control of direct fuel injection engine

Disclosed is a supercharged direct-injection engine, which comprises a supercharging device () for compressing intake air, and an injectorfor directly injecting fuel into a combustion chamber. In the engine, an excess air factor &#x3bb; as a ratio of an actual air-fuel ratio to a stoichiometric air-fuel ratio, at least in an engine warmed-up mode, is set to 2 or more in the entire engine-load region. Further, compressed self-ignited combustion is performed in a low engine-load region, and a supercharging amount by the supercharging device () is increased along with an increase in engine load in a high engine-load region to allow the excess air factor &#x3bb; to be kept at 2 or more. The engine of the present invention can effectively reduce NOx emission, while improving fuel economy.

Supercharged direct-injection engine

A multi-hole injector directly injects fuel into a combustion chamber. Intake air is introduced into the combustion chamber through intake ports to provide tumble flow in the combustion chamber. A cavity is formed in a part of the top surface of a piston which is eccentric to the exhaust side. In the intake stroke, fuel injection ends in a downstroke of a piston. When the crank angle is 100 degrees after the top dead center in the intake stroke at which the fuel injection ends, a most downward lower spray collides with a part of the top surface of the piston which ranges on the intake side from the edge on the exhaust side of the cavity. A most upward upper spray does not come into contact with a spark plug. Thus, the fuel injection can enhance the tumble flow to promote homogeneous dispersion of fuel-air mixture in the combustion chamber.

Internal combustion engine of spark-ignition direct-injection type and fuel injecting method thereof

Disclosed is an internal combustion engine (A), which has a valve overlap period (T) during which an intake valve () and an exhaust valve () are opened, and a geometric compression ratio of 13.0 or greater. The engine (A) is designed to satisfy, at a center timing (Tc) of the valve overlap period (T), a conditional expression: S&#x2267;Swhere Sis a cross-sectional area of a combustion chamber () taken along any selected one of a plurality of mutually parallel hypothetical cutting-planes (IP) each of which extends parallel to a linear reciprocating direction (dor d) of at least one of the intake and exhaust valves () and passes through a valve head (or) of the at least one of the valves (), and Sis an effective opening area defined between the valve head (or) and a corresponding valve seat (or) in a region on an outward side of the combustion chamber () relative to the selected hypothetical cutting-plane (IP). The present invention can reliably improve combusted-gas scavenging efficiency and intake-air charging efficiency.

Internal combustion engine

Disclosed is a direct-injection spark-ignition engine designed to promote catalyst activation during cold engine operation. A fuel injection timing for a fuel injection period in an compression stroke (second fuel injection period F2) is set to allow a first fuel spray Ga injected from a first spray holeto enter a cavityin a piston crown surface, and allow a second fuel spray Gb to impinge against a region of the piston crown surfacelocated closer to an injector than the cavity, so as to cause the second fuel spray Gb having a lowered penetration force due to the impingement to be pulled toward the cavityby a negative pressure generated in the cavityas a result of passing of the first fuel spray Ga therethrough. The direct-injection spark-ignition engine can maximally hold an injected fuel spray around a spark plug to reliably stabilize a combustion state in a combustion mode for promoting catalyst activation during cold engine operation, while enhancing combustion efficiency in a homogenous combustion mode during normal engine operation.

Direct-injection spark-ignition engine

A system and method of controlling an internal combustion engine are provided. The method may include closing said intake valve at a timing in a first range, which is before a maximum charge closing timing with which an amount of air inducted into said cylinder from said air intake passage would be maximized at a given engine speed, during a cylinder cycle when a desired amount of air to be inducted into said cylinder is less than or equal to a predetermined air amount at the given engine speed. The method may further include closing said intake valve at a timing in a second range, which is after said maximum charge closing timing and separated from said first range during a cylinder cycle, when a desired amount of air to be inducted into said cylinder is greater than said predetermined air amount at the given engine speed.

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Hiroshima, Japan

Toshiaki Nishimoto