A fuel feed unit has a base body with an intake channel section, into which a fuel opening opens. A partition wall section divides the intake channel section into a mixture channel and an air channel. The wall section has a recess in which the throttle flap at least partially lies in an end position. The wall section has, upstream of the recess, a continuous surface facing the mixture channel and which has lateral sections adjacent to the channel wall and a middle section running between the lateral sections. The lateral sections have, upstream of the throttle flap, a separation edge for the flow. In the end position, the side of the throttle flap facing the mixture channel defines a reference plane which divides the unit into a first region and a second region. The lateral sections extend, at least directly upstream of the recess, into the second region.

In at least some implementations, a method of forming a diaphragm for a liquid pump, includes clamping a substantially planar piece of material about a periphery, and plastically deforming the piece of material inboard of the clamped periphery. In at least some implementations, the material is plastically deformed by pressing a forming member against the material, or the material is plastically deformed by applying a fluid under pressure against the material.

[Problem] To provide a carburettor assembly which suppresses dripping of fuel from a nozzle to an air-fuel mixing passage during idling.

[Solution] The carburettor assembly comprises: a fuel chamber 12 for storing a fuel for supply to an air-fuel mixing passage 11; a nozzle 13 which comprises a check valve 13a and discharges the fuel to the air-fuel mixing passage 11, the nozzle 13 being arranged at a position in the air-fuel mixing passage 11 in which the fuel drops naturally; a plurality of holes 14 for discharging the fuel to the air-fuel mixing passage 11 during idling, at a position in an air-fuel mixture flow downstream from a position of the nozzle 13 in the air-fuel mixing passage 11; a fuel passage 15 for connecting the fuel chamber 12 and the nozzle 13 and also connecting the fuel chamber 12 and the plurality of holes 14; and a resistor 25 which is arranged in the fuel passage 15 between the fuel chamber 12 and the nozzle 13, and thereby forms resistance against a fuel flow directed to the nozzle 13.

In at least some implementations, a carburetor includes a body, a fuel pump diaphragm and a pressure pulse passage. The fuel pump diaphragm is carried by the body and defines in part a fuel chamber on one side of the fuel pump diaphragm and a pressure pulse chamber on the other side of the fuel pump diaphragm. The pressure pulse passage communicates the pressure pulse chamber with a pressure pulse source to provide pressure pulses in the pressure pulse chamber to actuate the fuel pump diaphragm. The pressure pulse passage includes an inlet communicating with a passage in which pressure pulses are present and the inlet is spaced from a surface defining the passage in which pressure pulses are present.

A carburettor for supplying gaseous fuels in internal combustion engines, comprises a main body in which there are defined an intake section, a first pressure reduction section, a second pressure reduction section connected to the first section, a supply section connected to the second pressure reduction section, a Venturi device connected to the supply section, wherein the Venturi device forms a central portion of the carburettor, the first pressure reduction section and the supply section extending on opposite sides of the Venturi device, the second supply section being interposed between the first pressure reduction section and the supply section and wherein the supply section further comprises an actuating device that can to allow passage of gas through a third connecting conduit towards the third chamber.

A carburettor for supplying gaseous fuels in internal combustion engines, comprises a main body in which there are defined an intake section, a first pressure reduction section, a second pressure reduction section connected to the first section, a supply section connected to the second pressure reduction section, a Venturi device connected to the supply section, wherein the Venturi device forms a central portion of the carburettor, the first pressure reduction section and the supply section extending on opposite sides of the Venturi device, the second supply section being interposed between the first pressure reduction section and the supply section and wherein the supply section further comprises an actuating device that can to allow passage of gas through a third connecting conduit towards the third chamber.

The invention concerns a method for controlling the fuel supply to an internal combustion engine at start-up, the engine having a fuel supply system. The invention also concerns a carburetor having a fuel supply system including a main fuel path connecting a diaphragm controlled regulating chamber to a main outlet in the region of the venturi section, the main fuel path including an actively controlled fuel valve, and an idling fuel path branching off from the main fuel path downstream of the valve and ending in at least one idling outlet in the region of a throttle valve, the fuel supply system further including a start fuel line starting upstream or downstream of the fuel valve and ending in at least one start fuel outlet to the intake channel.

The invention concerns a method for controlling the fuel supply to an internal combustion engine at start-up, the engine having a fuel supply system. The invention also concerns a carburetor having a fuel supply system including a main fuel path connecting a diaphragm controlled regulating chamber to a main outlet in the region of the venturi section, the main fuel path including an actively controlled fuel valve, and an idling fuel path branching off from the main fuel path downstream of the valve and ending in at least one idling outlet in the region of a throttle valve, the fuel supply system further including a start fuel line starting upstream or downstream of the fuel valve and ending in at least one start fuel outlet to the intake channel.

An air supply device (1) of a stratified scavenging two-cycle engine includes: a mixture passage (40) that penetrates a carburetor (2) and an insulator (3), the mixture passage being provided by a carburetor-side mixture passage (8) and an insulator-side mixture passage (21); a air passage (41) that is provided by a carburetor-side air passage (9) and an insulator-side air passage (22); a throttle valve (13) provided in a single bore (4) of the carburetor (2), the throttle valve(13) being provided by a butterfly valve that rotates in conjunction with a throttle operation; and a flow rate regulator (28) provided inside the air passage (41), the flow-rate regulator (28) bulging inward in the air passage (41). At least a part of a periphery of a valve body (17) of the throttle valve is close to the flow-rate regulator (28) until the valve body (17) is rotated from an initial position corresponding to an idling speed at a predetermined rotation angle.

An air supply device (1) of a stratified scavenging two-cycle engine includes: a mixture passage (40) that penetrates a carburetor (2) and an insulator (3), the mixture passage being provided by a carburetor-side mixture passage (8) and an insulator-side mixture passage (21); a air passage (41) that is provided by a carburetor-side air passage (9) and an insulator-side air passage (22); a throttle valve (13) provided in a single bore (4) of the carburetor (2), the throttle valve(13) being provided by a butterfly valve that rotates in conjunction with a throttle operation; and a flow rate regulator (28) provided inside the air passage (41), the flow-rate regulator (28) bulging inward in the air passage (41). At least a part of a periphery of a valve body (17) of the throttle valve is close to the flow-rate regulator (28) until the valve body (17) is rotated from an initial position corresponding to an idling speed at a predetermined rotation angle.