A Schnuerle scavenging two-stroke engine is provided that can keep combustion stability in a wide rotation speed range while suppressing blow-by. The engine of the present invention is a Schnuerle scavenging two-stroke engine (2). A scavenging passage (14(in1)) related to at least one scavenging port (16(in1)) has, at its upper end portion (14a(in1)), an intake-side wall surface (204). The intake-side wall surface (204) defines a first flow direction (42) of scavenging gas discharged from the scavenging port (16(in1)) at a height level of the scavenging port (16(in1)). The upper end portion (14a(in1)) of the scavenging passage (14(in1)) related to the scavenging port (16(in1)) has a guide portion (50) defining a second flow direction (44) of scavenging gas discharged from the scavenging port (16(in1)). The second flow direction (44) is deflected to the intake side from the first flow direction (42) at the height level of the scavenging port (16(in1)).

A Schnuerle scavenging two-stroke engine is provided that can keep combustion stability in a wide rotation speed range while suppressing blow-by. The engine of the present invention is a Schnuerle scavenging two-stroke engine (2). A scavenging passage (14(in1)) related to at least one scavenging port (16(in1)) has, at its upper end portion (14a(in1)), an intake-side wall surface (204). The intake-side wall surface (204) defines a first flow direction (42) of scavenging gas discharged from the scavenging port (16(in1)) at a height level of the scavenging port (16(in1)). The upper end portion (14a(in1)) of the scavenging passage (14(in1)) related to the scavenging port (16(in1)) has a guide portion (50) defining a second flow direction (44) of scavenging gas discharged from the scavenging port (16(in1)). The second flow direction (44) is deflected to the intake side from the first flow direction (42) at the height level of the scavenging port (16(in1)).

A buoyant hydrodynamic pump is disclosed that can float on a surface of a body of water over which waves tend to pass. The pump incorporates an open-bottomed tube with a constriction. The tube partially encloses a substantial volume of water with which the tube's constriction interacts, creating and/or amplifying oscillations therein in response to wave action. Wave-driven oscillations result in periodic upward ejections of portions of the water inside the tube that can be collected in a reservoir that is at least partially positioned above the mean water level of the body of water, or pressurized by compressed air or gas, or both. Water within such a reservoir may return to the body of water via a turbine, thereby generating electrical power (making the device a wave engine), or else the device's pumping action can be used for other purposes such as water circulation, propulsion, or cloud seeding.

An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode. Operation of the engine includes determining a combustion pressure parameter for each cylinder. Fueling for each cylinder is controlled responsive to a target state for the combustion pressure parameter for the corresponding cylinder. An end-of-injection timing and a corresponding spark ignition timing for each cylinder are controlled responsive to a target mass-burn-fraction point for an engine operating point.

A method for managing the mass of fuel injected into the cylinder of an internal combustion engine fed by direct injection. The pressure and the pressure drop per unit of time are monitored (13) during the starting phase. If the pressure becomes too low (7), or if it drops too quickly (9), the mass of fuel injected on each cycle is adjusted (15) in order to maintain a high fuel pressure in the injector (37). The method can be applied, for example, in the event of low-temperature starting using any type of fuel, for example pure or mixed ethanol.

A gas injector for injecting a gaseous fuel directly into a combustion chamber of an internal combustion engine includes a valve-closing element for releasing and sealing a through opening at a sealing seat; a shielding element, which is situated at an end of the valve-closing element on a side of the combustion chamber and which shields the valve-closing element and the sealing seat with respect to the combustion chamber; and a cooling ring having a first contact area designed for direct contact with the shielding element and a second contact area designed for direct contact with a component of the internal combustion engine, in particular with a cylinder head.

A two-stroke engine piston (1) is disclosed comprising a piston top (3), a mantle surface (5), a stratified scavenging channel (7) in the mantle surface (5), and a weight reduction space (9) arranged between the piston top (3) and the stratified scavenging channel (7). The weight reduction space (9) has a largest first axial extent (a1) at the mantle surface (5) and a second axial extent (a2) radially inside the mantle surface (5), and wherein the second axial extent (a2) is greater than the largest first axial extent (a1). The present disclosure further relates to an engine (30), a hand-held tool (40), and a method of manufacturing an engine piston (1).

A two-stroke engine piston (1) is disclosed comprising a piston top (3), a mantle surface (5), a stratified scavenging channel (7) in the mantle surface (5), and a weight reduction space (9) arranged between the piston top (3) and the stratified scavenging channel (7). The weight reduction space (9) has a largest first axial extent (a1) at the mantle surface (5) and a second axial extent (a2) radially inside the mantle surface (5), and wherein the second axial extent (a2) is greater than the largest first axial extent (a1). The present disclosure further relates to an engine (30), a hand-held tool (40), and a method of manufacturing an engine piston (1).

The invention relates to a control device applied to a cylinder injection type of the engine (10). The control device carries out a fuel injection while changing a penetration force of the injected fuel by changing a maximum value of a lift amount of the valve body (22) of the injector (20). Further, the control device controls an ignition timing on the basis of the engine operation state. The control device changes an end timing of a preceding injection carried out immediately before the ignition timing such that a time period between the end timing of the preceding injection and the ignition timing under a state where a first value is set as the maximum value of the valve body lift amount in the preceding injection, is longer than a time period between the end timing of the preceding injection and the ignition timing under a state that a second value larger than the first value is set as the maximum value of the valve body lift amount in the preceding injection.

A direct fuel injection internal combustion engine having an injector for directly injecting fuel into a combustion chamber thereof is provided. The engine is configured so that a tumble flow is generated in the combustion chamber. A fuel injection by the injector can be performed in a first injection mode and a second injection mode, the first injection mode being a mode in which the fuel injection is completed after the tumble flow is generated, and the second injection mode being a mode in which the fuel injection is completed before the tumble flow is generated. The fuel injection of the first injection mode is performed before completion of the warming-up of the engine, and the fuel injection of the second injection mode is performed after completion of the warming-up of the engine.