Walbro Engine Management, L.l.c.

Walbro Japan, Inc.

Yoshiaki Douyama

Ronald H Roche

Kevin L Israelson

Shinichi Ohgane

Kerry E Grifka

Edward J Talaski

Teruhiko Tobinai

Jun Takano

Joseph M Graham

Toshimasa Takahashi

Tamio Aihara

Harunori Seki

Kerry E Griffka

A scavenging valve assembly is used in a carburetor. The valve assembly includes a throttle valve and a rotary air valve. The throttle valve opens and closes an air-fuel passage. The rotary air valve opens and closes an air passage and has one or more air bore(s). When the rotary air valve begins to rotate, airflow travels through the bore(s) and the size of an opening area that airflow travels through continuously increases in size.

Layered scavenging carburetor

A fuel delivery system for a combustion engine has a fuel tank which defines an access hole preferably communicating through either the top wall or bottom wall of the tank. An associated top or bottom flange, both having a fuel channel for flowing fuel out of the tank, sealably covers the access hole. A fuel pump module is located in the fuel chamber of the tank and has a universal, structural, pod which engages either the top or bottom flange while preferably maintaining an axial upright position. The pod defines an axially extending first bore for housing a fuel pump and preferably an electric pump motor and a second bore defined by a cylindrical inner face and spaced radially outward from the first chamber for housing a reversible filter cartridge of the module. The pod also has a fuel discharge nozzle which generally defines a counter bore that communicates axially with the second bore. Fuel flows into the pump through an inlet defined by the pod and pressurized fuel flows from the pump and into the second bore via a fuel passage preferably defined by the pod. The filter cartridge preferably has a filter element generally spaced from the pod within the second bore for filtration efficiency by a primary end retainer and an opposite secondary end retainer. The end retainers generally seal to the pod within the second bore thus flowing all of the pressurized fuel from the fuel passage and through the filter element before being discharged from the second bore as supply fuel and/or bypass fuel. Preferably, filtered fuel flows through the primary end retainer as system supply fuel to a combustion engine and the remaining filtered fuel flows through the secondary end retainer as bypass fuel back into the fuel tank chamber.

Integrated fuel delivery system

A scavenging carburetor having an improved relationship between scavenging air flow and fuel-and-air flow to an engine over its range of operating conditions. The carburetor has a butterfly throttle valve and a plug-type scavenging valve. Levers are attached to support shafts of the valves and are connected to each other by a connecting rod so as to synchronize movement of the valves. Because of the different opening angle versus open area properties of the two valves, the supply of the scavenging air is minimized over a low speed range of the engine so as to achieve a stable low speed operation and a stable acceleration from idle conditions and a relatively large amount of scavenging air is supplied over a high speed range of the engine for the given amount of fuel-and-air mixture that is supplied. Therefore, the fuel-and-air mixture supply and scavenging air supply is better matched to the requirements of a particular engine than was possible with conventional combinations of valves.

Scavenging carburetor

A fluid pump includes an electric motor with a casing and a drive shaft extending from the casing, a pumping element coupled to the drive shaft for rotation with the shaft to take in fluid and discharge it under pressure. The fuel pump casing may be sealed and a housing coupled to the casing may provide the inlet and outlet passages for fluid flow to and from the pumping element. The housing may be received in or communicated with other housing or module assemblies to provide a wide array of fuel pump assemblies. The pumping element may include one or more gear rotors, a turbine pumping element, or other pumping element, as desired.

Fluid pump assembly

A low cost bypass pressure regulator preferably for a returnless fuel system supplying liquid fuel to a fuel injector of the combustion engine. The pressure regulator preferably has a valve head disposed at least in part in a valve chamber defined by a circumferentially continuous inner surface carried by a valve body and which transitions radially outward with respect to a center axis and in a downstream direction. The valve head preferably tapers radially inward from a downstream peripheral outer edge of the head. In a closed position, the valve head engages a seat carried by the body with the peripheral outer edge downstream of the seat and radially spaced from and fitted closely to the valve chamber continuous inner surface thus defining a close fit region therebetween. As the valve head opens, the flow cross-section enlarges which reduces or eliminates oscillation of the valve head.

Bypass pressure regulator

A rotary throttle valve carburetor includes a body having a fuel and air mixing passage and a throttle valve movable between idle and wide open positions. A valve bore is increasingly aligned with the fuel and air mixing passage as the throttle valve is moved from idle toward its wide open position. A fuel metering needle is responsive to movement of the throttle valve so that the needle moves relative to the body in response to movement of the throttle valve. A fuel nozzle extends into the valve bore, is associated with the fuel metering needle, and has a fuel ejection passage with an effective flow area controlled by movement of the fuel metering needle relative to the fuel nozzle and includes a portion with a cross-sectional area that gradually increases in the direction of fuel metering needle movement corresponding to throttle valve movement toward its wide open position.

Rotary throttle valve carburetor

A limiter cap assembly of a carburetor for a two cycle engine restricts maximum and minimum fuel amounts. The limiter cap assembly has a first cap engaged telescopically to the end of a low speed needle valve and a second cap engaged telescopically to the end of a high speed needle valve. The first and second caps are identical, each having a first tab and a second tab. The first tab sets the maximum fuel amount by contacting the adjacent cap and the second tab sets the minimum fuel amount by also engaging the adjacent cap. The first and second tabs are axially spaced apart so as not to obstruct rotation of the adjacent cap via the adjacent tabs. A housing having a lid encompasses the first and second caps. The caps each have a plurality of projections which engage an inner edge of the lid, thereby, provisionally staging the caps to the carburetor while final needle valve adjustments are made.

Growing community of inventors

Shiroishi, Japan

Yoshiaki Douyama