Title of Invention

A FUEL INJECTION SYSTEM FOR A MOTOR VEHICLE

Abstract

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 an on-return valve is provided in the fuel line; and an accumulator is also provided in the fuel line, between the non-return valve and the injector, the accumulator storing air entrapped under pressure exerted by the fuel in the fuel line.

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 is 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 •.creuiDg tk. feel pre.»r«. If A. battery » r». down me 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 fnel pump to rati 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 die fuel pump through a fuel line, characterised in that a non¬return valve is provided in the fuel line; and an accumulator is also provided in the fuel line between the non-retain valve and the injector, the accumulator storing air entrapped under pressure exerted by the fuel in the fuel line. 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 Imitation, 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 die fuel tank T. According to die 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 pomp. Consequently the engine caanot be started unless the magneto is of high capacity for enabling requisite power generation at low speeds. To meet such a situation, this invention proposes a non¬return 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, bat which prevents the flow of feel in the other direction, that is to any. along the direction of the arrow B. This invention also proposes an accumulator E in the fuel line L. Air is entrapped in the accumulator at M by the fuel G in the fuel line L. This entrapped air is under pressure from the fuel Q in the fuel late I, during normal running of the engine. Now, when the enghte 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 preisure in the fuel line L, the pressure of the entrapped air at M in the accumulator supplies the requisite pressure 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 at M is retained inside the accumulator E since the fuel in the fuel line I 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 hi the direction of (he arrow A by the iajector I Onoe started, the generator of the vehicle takes over to operate the fuel pump F and run the engine m the normal way. The terms and expressions herein are of deicription 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 non-return valve is provided in the fuel line; an accumulator is also provided in the fuel line between the non-return valve and the injector, the accumulator storing air entrapped underpressure exerted by the fuel in the fuel line. 2.A fuel injection system for a motor vehicle as claim ed in Claim 1 wherein the source of electric power is a battery. 3. A fuel injection system for a motor vehicle as claimed in Claim 1 or Claim 2 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. Dated this 11nth day of March 2004

Documents:

0235-che-2004-abstract.pdf

0235-che-2004-correspondnece-others.pdf

0235-che-2004-correspondnece-po.pdf

0235-che-2004-drawings.pdf

0235-che-2004-form 1.pdf

0235-che-2004-form 26.pdf

0235-che-2004-form 3.pdf

235-che-2004-claims duplicate.pdf

235-che-2004-claims original.pdf

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

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

235-che-2004-form 19.pdf