An intake system for an internal combustion engine has at least one inlet channel through which air can flow and by which the air flowing through the inlet channel is to be conducted into at least one combustion chamber of the internal combustion engine. The inlet channel is, on the bottom side thereof, of flat form at least in one length region, wherein the flat bottom side extends as far as a tumble edge by which a tumbling flow of the air flowing into the combustion chamber can be effected.

An engine control device controls control amounts of a variable valve mechanism and a spark plug, the control amounts in a homogeneous lean operation region set in a first load region are different from that in a non-lean operation region which is a stoichiometric or rich operation region set in a second load region higher than the first load region. The control device performs control, in other operation region set in a third load region between the first and second load region, so that an air-fuel ratio of the internal combustion engine is equal to that of non-lean operation region, the control amount of the variable valve mechanism is equal to that of homogeneous lean operation region and the control amount of the spark plug is equal to that of the non-lean operation region in accordance with an operation amount of an accelerator pedal.

In a drive force transmission device, a shock-absorbable rubber is placed between a driving-side rotatable body and a driven-side rotatable body. A bridge portion is placed at a deep side of a holding recess of the shock-absorbable rubber and connects between a primary damper portion and a secondary damper portion. At least one cut part penetrates through the bridge portion in an axial direction of the shock-absorbable body and extends in a radial direction of the shock-absorbable body.

A gasoline-diesel complex combustion engine may include a cylinder including a cylinder body in which a combustion chamber is formed to generate a driving power by combusting a gasoline fuel and a diesel fuel and a cylinder head formed to cover an upper portion of the cylinder body, a pair of intake ports formed in the cylinder head, a pair of exhaust ports formed in the cylinder head, a diesel injector disposed in a center of the cylinder head, a pair of spark plugs disposed on opposite sides of the diesel injector, a first intake pipe and a second intake pipe mounted in the intake ports, an exhaust pipe mounted in the exhaust ports, a pair of intake valves disposed in the first and second intake pipes, and a gasoline injector disposed in the first and second intake pipes to inject the gasoline fuel into the combustion chamber.

An apparatus and a method control an internal-combustion engine with a fuel injection valve for injecting fuel into an inlet port. In fuel injection control, injection field pressure at injection start timing is estimated from engine rotation speed and injection starting timing of the fuel injection valve. Since flow rate of the fuel injection valve fluctuates when a fuel accumulating space between a valve body and injection holes of the fuel injection valve changes by injection field pressure, a correction value to correct flow rate fluctuations is calculated based on injection field pressure at injection start timing. Fuel injection by the fuel injection valve is controlled by setting the result of adding the correction value to an injection pulse width calculated from intake air flow, engine rotation speed, etc., to final injection pulse width. Air-fuel ratio error is thereby reduced even when injection field pressure at injection timing changes.

A combustion chamber for an opposed-piston engine includes a squish zone defined between circumferential peripheral areas of opposing end surfaces of the pistons, a cavity defined by one or more bowls in the end surfaces, and at least one injection port that extends radially through the squish zone into the cavity. The cavity has a cross-sectional shape that imposes a tumbling motion on air flowing from the squish zone into the cavity.

An intake port of an internal combustion engine is connected to a combustion chamber and includes a connecting portion having a passage cross-sectional area that increases as the connecting portion approaches the combustion chamber, and an upstream portion connected to an upstream end of the connecting portion. The connecting portion is provided at its downstream end with a valve seat with which an umbrella part of an intake valve is brought into contact. At least one recess extending in an extending direction of the intake port and included in the connecting portion and the upstream portion is provided at least at one of two portions, the two portions located on both sides in an extending direction of an output shaft, of a peripheral surface of the intake port.

A valve body unit (11) in which a plurality of valve bodies (17) which open and close intake passages (10) are attached on a rotational shaft (16) is inserted into inner sides of housing passages (28) of a housing (12) and, thereafter, a holder (13) is mounted in the housing (12) to rotatably support the valve body unit (11). A flange (14) is fixed onto an upper surface of the housing (12) on the holder (13) by means of a vibration welding and the holder (13) is retained with this flange (14) and the housing (12).

The present invention provides an intake control device that appropriately restricts the flow of intake air when a valve body is set to a restriction position while the valve body is smoothly operated. The valve body is configured such that it is supported so as to be capable of swinging with respect to a sleeve, and when the valve body is set to the restriction position, a main valve portion of the valve body is lifted upward from a bottom plate, and a secondary valve portion of the valve body is sunk into an accommodating space of the bottom plate. In the accommodating space, a stepped portion that allows outward displacement from an inner surface of the sleeve is formed, and a seal portion that is brought closer to the stepped portion when the valve body is set to the restriction position is formed in the secondary valve portion.

Provided is a control device of an engine that can certainly suppress and avoid pre-ignition. A control device of an engine is an engine control device for controlling the behavior of fuel that is directly injected into a combustion chamber of a cylinder by a tumble flow, and it has an injector that directly injects the fuel into the combustion chamber, an intake port that generates the tumble flow in the combustion chamber, and an ECU that injects the fuel from the injector at a plurality of injection timings including an intake-stroke-early-half injection timing that is set at an early half of the intake stroke of the cylinder, when an operating state of the engine is in a high-load, low-rotation range.