Title of Invention

A FUEL INJECTION SYSTEM FOR A MOTOR VEHICLE

Abstract

A fuel injection system for motor vehicle comprises a fuel pump for connection to a source of electric power,fuel tank and regulator;an inject5or for connection to a controller and to the fuel pump through a fuel line,characterised in that a non-return valve is provided in the fuel line;an airtight chamber made of a an elastic material is also provided in the fuel line between the non-return valve and the injector,said chamber having air under pressure entrapped therein such entrapped air supplying the requisite pressure to force the fuel in the line through the injector and start the engine.

Full Text

This invention relates to a fuel injection system for motor vehicles, particularly, though not exclusively, for two wheeler and three wheeler motor vehicles. Fuel injection systems are increasingly being used in internal combustion engines to replace the carburettor mainly in order to comply with emission norms as well as to achieve better fuel economy The known fuel injection system requires a power source e.g. a battery or generator to work the fuel pump for increasing the fuel pressure. If the battery is run down the fuel pump cannot create sufficient pressure at the injector and the vehicle cannot be started. On the other hand if the system is designed to work without a battery it has to use a high power generator, to generate the required output during kick starting, which is expensive. The object of this invention is to propose a fuel injection system which can be operated, even when the battery is run down, and without use of a high power generator. Once the engine starts, the generator of the vehicle provides the necessary power to the fuel pump to run the engine. Various features of the fuel injection system proposed herein will be apparent from the following description given hereunder. The fuel injection system for a motor vehicle, according to this invention, comprises a fuel pump for connection to a source of electric power, fuel tank and regulator; an injector for connection to a controller and to the fuel pump through a fuel line, characterised in that a nonreturn valve is provided in the fuel line; an air-tight chamber m ade of an elastic material is also provided in the fuel line between the non-return valve and the injector, said chamber having air under pressure entrapped therein, such entrapped air supplying the requisite pressure to force the fuel in the fuel line through the injector and start the engine. This invention will now be described with reference to the single Figure in the accompanying drawings which illustrates, by way of example, and not by way of limitation, one of various possible embodiments of the fuel injection system proposed herein. A fuel pump F is connected to a source of electric power P, usually a battery and generator, or a generator, a fuel tank T and fuel pressure regulator R. The fuel from the tank T is pumped by the fuel pump F, through a fuel line L, to an injector I whence the fuel passes on to the controller C to the engine. The regulator R sends fuel, pumped by the fuel pump F, exceeding a given pressure value, back to the fuel tank T. According to the above mentioned arrangement, whenever the battery is run down, and the engine is OFF, there is no sufficient power to operate the fuel pump F. In the absence of a battery, the power from the magneto (generator) obtained by kick starting the vehicle may not also be sufficient to operate the fuel pump. Consequently the engine cannot be started. To meet such a situation, this invention proposes a nonreturn valve V in the fuel line L, which allows fuel from the fuel pump F, into the fuel line L, along the direction of the arrow A, to the injector I, but which prevents the flow of fuel in the other direction, that is to say, along the direction of the arrow B. This invention also proposes an air-tight chamber E in the fuel line L. The chamber is made of an elastic material such as rubber, elastomer. Pressurised air is entrapped in the chamber E. In addition to providing the requisite pressure on the fuel in the fuel line, during starting (by reason of the elasticity of the chamber wall) the chamber does not permit the air within it to be sucked out through the injector, during suction strokes of the engine, since the chamber £ is hermetically sealed. Now, when the engine is OFF and required to be started, with the battery in run down condition, although the fuel pump F does not build up the requisite pressure in the fuel line L, the pressure of the entrapped air in the chamber E supplies the requisite pressure (by reason of the elasticity of the chamber wall) to force the fuel G in the fuel line L through the injector I and start the engine. When the engine is OFF the pressure of the entrapped air is retained inside the chamber £ since the fuel in the fuel line L is prevented from leaving the fuel line in the direction of the arrow B and, at the same time, is also prevented from leaving the fuel line in the direction of the arrow A by the injector I. Once started, the generator of the vehicle takes over to operate the fuel pump F and run the engine in the normal way, and the chamber E regains the pressure of the entrapped air. In the event that the engine is sought to be kick started, even when there is no fuel in the fuel line, there is no possibility of the entrapped air in the chamber £ being sucked out through the injector, during every suction stroke of the engine, because the said chamber ia sealed all around. The terms and expressions herein are of description and not of limitation, inasmuch as various other embodiments of the fuel injection system proposed herein are possible without departing from the scope and ambit of this invention. We Claim: 1. A fuel injection system for a motor vehicle, comprising a fuel pump for connection to a source of electric power, fuel tank and regulator; an injector for connection to a controller and to the fuel pump through a fuel line, characterised in that a n on -return valve is provided in the fuel line; an air-tight chamber made of an elastic material is also provided in the fuel line between the non-return valve and the injector, said chamber having air under pressure entrapped therein, such entrapped air supplying the requisite pressure to force the fuel in the fuel line through the injector and start the engine. 2. A fuel injection system for a motor vehicle as claimed in Claim 1 wherein the source of electric power is a battery. 3.A fuel injection system for a motor vehicle as claim ed in any one of the preceding Claims wherein the source of electric power is a generator. 4.A fuel injection system for a motor vehicle substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

Documents:

722-che-2004-abstract.pdf

722-che-2004-claims duplicate.pdf

722-che-2004-claims original.pdf

722-che-2004-correspondnece-others.pdf

722-che-2004-correspondnece-po.pdf

722-che-2004-description(complete) duplicate.pdf

722-che-2004-description(complete) original.pdf

722-che-2004-drawings.pdf

722-che-2004-form 1.pdf

722-che-2004-form 26.pdf