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US 6,871,843 B2Granted
Carburetor with idle fuel supply arrangement
AssigneeWalbro Japan, Inc.
InventorsTakashi Abei, Hidenori Sasaki, Masao Suzuki
Life of this patent
Estimating the term…
Abstract
An idle fuel supply device for a carburetor has an idle air passage that communicates with an air intake passage and a fuel chamber. A passage extending from a fuel metering chamber is connected to the fuel chamber preferably via a fuel adjusting needle valve. A low speed fuel nozzle hole communicates the fuel chamber with the air intake passage in the vicinity of a throttle valve when in its idle position. A passage communicates with the fuel chamber and the idle air passage, so that fuel and air may mix in at least a portion of the idle air passage.
Claims16
A carburetor, comprising:
- a body having an air intake passage and a fuel chamber formed therein, the fuel chamber being in communication with a supply of liquid fuel;
- a throttle valve disposed at least in part in the air intake passage and being movable to and away from an idle position wherein the throttle valve controls at least in part the air flow through the air intake passage to support idle operation of an engine;
- at least one low speed fuel nozzle communicating with a supply of liquid fuel and the air intake passage upstream of the throttle valve when the throttle valve is in its idle position;
- and
- a separate idle air passage formed in the body in communication at one end with the air intake passage upstream of the throttle valve at least when the throttle valve is in its idle position, the idle air passage communicates at its other end with the air intake passage downstream of the throttle valve at least when the throttle valve is in its idle position, and the idle air passage communicates with the fuel chamber between the ends of the idle air passage so that liquid fuel from the fuel chamber will be atomized in a flow of air in the idle air passage to discharge a fuel and air mixture from the idle air passage into the air intake passage downstream of the throttle valve when in its idle position and to the engine at least during idle operation of the engine.
2 more elements
A carburetor, comprising:
- a body having an air intake passage and a fuel chamber formed therein, the fuel chamber being in communication with a supply of fuel;
- a throttle valve disposed at least in part in the air intake passage and being movable to and away from an idle position wherein the throttle valve controls at least in part the air flow through the air intake passage to support idle operation of an engine;
- an idle air passage formed in the body in communication at one end with the air intake passage upstream of the throttle valve at least when the throttle valve is in its idle position and an choke valve when in its closed position, the idle air passage communicates at its other end with the air intake passage downstream of the throttle valve at least when the throttle valve is in its idle position, and the idle air passage communicates with the fuel chamber between the ends of the idle air passage so that liquid fuel from the fuel chamber will be atomized in a flow of air in the idle air passage to discharge a fuel and air mixture from the idle air passage into the air intake passage downstream of the throttle valve when in its idle position and to the engine at least during idle operation of the engine;
- an air passage formed in the body in communication with the air intake passage and the idle air passage;
- a fuel reservoir in which a supply of fuel is received;
- and
- a low speed fuel supply pipe in communication at one end with the fuel reservoir and at its other end with said air passage whereby fuel may flow from the fuel reservoir, through the low speed fuel supply pipe, to the air passage, to the idle air passage, and then into the air intake passage.
4 more elements
Dependencies are inferred from the claim text.