This invention relates to a device for direct injection of gasoline into a combustion system, such as, an internal combustion engine.

Such devices are known to the art and are commonly called fuel injectors based on gasoline direct injection (GDI) technology

This invention proposes a device as aforesaid which is capable of a plurality of switchable injection modes using a single device, the injection modes being selectively predetermined by a controller .to correspond to various air fuel spray patterns, such as, a stratified fuel distribution obtainable by a concentrated spray pattern from a central orifice in a nozzle; a homogeneous fuel distribution obtainable by a circumferential spray pattern from an array of orifices on the nozzle; and a combination of the two spray patterns for homogeneous fuel distribution at high power applications, to provide three alternative modes, from a single unit. It can be visualized that other spray patterns can be introduced to obtain corresponding modes as circumstances may require.

The device proposed herein is simple in its construction, effective in its operation and performance, contributing to ease and economy in use. Various other features of this invention will be apparent from its following description.

The device proposed herein will now be described with reference to the accompanying drawing which illustrates, by way of example, and not by way of limitation, one of various possible embodiments of this invention.

A fuel chamber F dispenses pressurized gasoline G into the combustion chamber of the said system, which, for example, is the cylinder of an internal combustion engine. A nozzle N is provided for the fuel chamber.

A first orifice set consisting of at least one central orifice Q provided at the tip of the nozzle N, communicates with the interior of the fuel chamber F and the interior of the cylinder of the said engine so that gasoline from within the chamber (which is under pressure) is capable of emerging as a spray from the orifice Q into the engine cylinder whenever the orifice Q is opened. The injection ceases when the orifice is closed.

A second orifice set consisting of a circumferential array of orifices R provided on the side wall of the nozzle N, communicates with the interior of the fuel chamber F and the cylinder of the interior of the said engine., so that gasoline from within the chamber (which is under pressure) is capable of emerging as a spray from the orifices R into the engine cylinder whenever the orifices R are opened. The injection ceases when the orifices are closed.

Regularly timed sprays from the orifices aforesaid are injected into the cylinder whenever the orifices are opened and closed. A controller is connected to means for selectively activating either or both the above mentioned sets to successively open and close the orifices, to periodically inject gasoline from the fuel chamber F into the cylinder of the engine. One of possible forms of such means consists of two solenoids T with spring-loaded stopper arms P which, when successively energized and de-energized, activate the stopper arms, reciprocatingly, to periodically open and close the corresponding orifices to inject gasoline from the chamber (which is under pressure) into the engine cylinder. The controller determines which set of orifices is to be opened and closed by the stopper arms, whether the Q set or the R set or both sets.

The timing of the injection is predetermined by the controller to obtain optimum combustion of the gasoline, at all load conditions of the said system. At part-load it would suffice to have the Q set operative for a low rate of injection of fuel; at full load it is necessary to have the R set operative to provide a higher rate of injection of fiiel; and at greater than full load, both Q and R sets are made operative.

It will be visualized that further sets of orifices can be provided with corresponding number of stopper arms for meeting given load requirements.

From the foregoing description it will be appreciated that various .other embodiments of the device proposed herein are possible without departing from the scope and ambit of this invention.

1. A device for direct injection of gasoline into a combustion system, comprising a fuel chamber for dispensing pressurized gasoline into the combustion chamber of the said system; a nozzle provided for the fuel chamber; a first orifice set consisting of at least one orifice provided for the nozzle for communication between the interior of the fuel chamber and the interior of the said combustion chamber; a second orifice set consisting of circumferential orifices provided for the nozzle, also for communication between the interior of the fuel chamber and the interior of the said combustion chamber; a controller connected to means for selectively activating either or both the above mentioned sets to successively open and close the orifices, to periodically inject gasoline from the fuel chamber into the said combustion chamber, the timing of the injection being predetermined by the controller to obtain optimum combustion of the gasoline in the combustion chamber, at all load conditions of the said system.

2.A device as claimed in Claim 1 wherein the first orifice set is provided at the tip of the nozzle.

3.A device as claimed in Claim 1 or Claim 2 wherein the second orifice set is provided on the side wall of the nozzle.

4. A device as claimed in any one of the preceding Claims wherein the means for selective activation by the controller consist of spring-loaded stopper arms accommodated within the fuel chamber with solenoids actuating the stopper arms reciprocatingly to successively open and close the orifices .

5. A device for direct injection of gasoline into a combustion system, substantially as herein described with reference to, and as illustrated in, the accompanying drawings.