An engine system of the present disclosure includes an engine configured to drive a plurality of pistons by burning a mixture of air and gas, an air supply pipe through which the air supplied to the engine flows, a supercharger configured to compress the air flowing through the air supply pipe, a gas supply pipe through which the gas supplied to the engine flows, and a mixer configured to mix the air that has passed through the supercharger and the gas. The mixer has a venturi tube shape in which a cross-sectional area of a flow path decreases and expands in a flow direction of the air that has passed through the supercharger, and the gas supply pipe is connected to a portion of the mixer where the cross-sectional area of the flow path in the mixer is decreased.

An engine system of the present disclosure includes an engine configured to drive a plurality of pistons by burning a mixture of air and gas, an air supply pipe through which the air supplied to the engine flows, a supercharger configured to compress the air flowing through the air supply pipe, a gas supply pipe through which the gas supplied to the engine flows, and a mixer configured to mix the air that has passed through the supercharger and the gas. The mixer has a venturi tube shape in which a cross-sectional area of a flow path decreases and expands in a flow direction of the air that has passed through the supercharger, and the gas supply pipe is connected to a portion of the mixer where the cross-sectional area of the flow path in the mixer is decreased.

An engine includes a combustion chamber, a cylinder head, an intake valve, a partition wall plate, and a tumble valve. The cylinder head includes an intake port that communicates with the combustion chamber. The intake valve includes a head configured to open and close an open end of the intake port. The partition wall plate partitions the intake port into first and second passages. The tumble valve is configured to open and close either one of the first passage and the second passage. A cross sectional shape of the partition wall plate is defined on a basis of a shape of a gap that is surrounded by a contour of the head and a contour of the open end, as viewed in a reference direction. The reference direction is a direction from a reference point in the intake port to a gap between the open end and the head.

An engine includes a combustion chamber, a cylinder head, an intake valve, a partition wall plate, and a tumble valve. The cylinder head includes an intake port that communicates with the combustion chamber. The intake valve includes a head configured to open and close an open end of the intake port. The partition wall plate partitions the intake port into first and second passages. The tumble valve is configured to open and close either one of the first passage and the second passage. A cross sectional shape of the partition wall plate is defined on a basis of a shape of a gap that is surrounded by a contour of the head and a contour of the open end, as viewed in a reference direction. The reference direction is a direction from a reference point in the intake port to a gap between the open end and the head.

An internal combustion engine for use with hydrogen fuel, the engine having at least one cylinder assembly which includes a combustion chamber having a cylinder, a cylinder head and a reciprocating piston assembly, the cylinder defining a cylinder longitudinal axis; a fuel injector for injecting fuel into the combustion chamber, the fuel injector defining an injector longitudinal axis; and a fuel flow director, wherein the fuel flow director is located in the fuel flow path between an outlet of the fuel injector and the combustion chamber. The fuel injector is oriented such that the injector longitudinal axis extends at a first angle; and the fuel flow director is configured to direct fuel flow into the combustion chamber at a second angle, different to the first angle.

A valve system that includes a housing defining an intake port, a cylinder port and a valve bore; wherein the intake port defining a valve seat portion at an interface between the intake port and the cylinder port. The valve system also includes a valve to control fluid communication between the intake port and the cylinder port. The valve includes a valve stem disposed within the valve bore and extending into the cylinder port and extending out of the housing, the valve stem having an open face exposed to atmospheric pressure and a valve head coupled to the valve stem comprising a first face and an opposing second face. A diameter of the valve stem is selected to control a closing force on the first face of the valve head.

A valve system that includes a housing defining an intake port, a cylinder port and a valve bore; wherein the intake port defining a valve seat portion at an interface between the intake port and the cylinder port. The valve system also includes a valve to control fluid communication between the intake port and the cylinder port. The valve includes a valve stem disposed within the valve bore and extending into the cylinder port and extending out of the housing, the valve stem having an open face exposed to atmospheric pressure and a valve head coupled to the valve stem comprising a first face and an opposing second face. A diameter of the valve stem is selected to control a closing force on the first face of the valve head.

Among multiple scavenging passages 14 included in a cylinder, a scavenging passage connected to at least one scavenging port 16 constitutes a variable scavenging passage 14(ch). An upper end portion of the variable scavenging passage 14(ch) has a guide surface 50 defining a discharge direction of a scavenging gas discharged from a variable scavenging port 16(ch) connected thereto on a horizontal plane. The guide surface 50 includes at least a first guide portion 50(H) defining a first discharge direction of the scavenging gas and a second guide portion 50(L) defining a second discharge direction of the scavenging gas. The discharge direction of the scavenging gas is changed from the first discharge direction to the second discharge direction on the horizontal plane by the first and second guide portions 50(H) and 50(L) in the scavenging stroke.

An air intake device includes: an air intake valve provided so as to change intake air by rotation of a rotation shaft; an actuator which is a driving source for rotating and driving the rotation shaft of the air intake valve; a first link member rotatable by a predetermined operation angle about the rotation shaft; a second link member rotatably connected to the first link member; a connection member which connects the first link member and the second link member so as to be rotatable to each other; and a biasing member whose one side end is engaged to the first link member and whose other side end is engaged to the second link member or the connection member to bias the first link member and the second link member or the connection member so that rattling between the first link member and the second link member is suppressed.

An air intake device includes: an air intake valve provided so as to change intake air by rotation of a rotation shaft; an actuator which is a driving source for rotating and driving the rotation shaft of the air intake valve; a first link member rotatable by a predetermined operation angle about the rotation shaft; a second link member rotatably connected to the first link member; a connection member which connects the first link member and the second link member so as to be rotatable to each other; and a biasing member whose one side end is engaged to the first link member and whose other side end is engaged to the second link member or the connection member to bias the first link member and the second link member or the connection member so that rattling between the first link member and the second link member is suppressed.