GB2059502A

GB2059502A - Gauze Atomiser for Carburetted Mixture

Info

Publication number: GB2059502A
Application number: GB8022661A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-09-25
Filing date: 1980-07-10
Publication date: 1981-04-23
Also published as: GB2059502B

Abstract

A cylindrical sleeve 21 of fine mesh gauze is fitted at the base of a carburettor to project into the intake manifold. The sleeve may have a domed solid bottom end plate 23 and/or a transverse fine mesh gauze wall 24 with a diametrically extending depression 26. <IMAGE>

Description

SPECIFICATION Fuel Economy Device for a Petrol Engine Background to the Invention This invention relates to a fuel economy device for a petrol engine.

In a conventional petrol engine, as fitted in a motor vehicle, disadvantageous fuel wastage is caused by the drawing into the induction manifold of fuel which remains in liquid particle or globule form. Generally, this leads to increased use of the choke when starting and, during normal running when the accelerator pedal is depressed, the suction into the induction manifold of a greater quantity of fuel than that which is actually needed to power the engine, since the fuel drawn into the manifold in liquid form is not vapourised until hitting the manifold base, in consequence of which it is largely wasted.

It is an object of the present invention to minimise or overcome the above-stated problem of fuel wastage.

According to the invention, there is provided a fuel economy device for a petrol engine which comprises a hollow element having a wall of fine mesh gauze, and means for mounting said element at the base of the carburettor with said element projecting into the induction manifold in use to receive into its interior the fuel/air flow exiting from the carburettor and to transmit into the induction manifold through its gauze wall only fuel which is in finely atomised or vapourised form.

When this device is fitted to the engine of a motor vehicle, the liquid fuel particles or globules exiting from the carburettor tend to adhere to the fine mesh gauze wall, on the interior of the hollow element, until being blown through by the prevailing suction action. In the process of being blown through the fine mesh gauze, these liquid particles or globules are broken up into finely atomised form. Thus, substantially only fuel in finely atomised or vapourised form is fed to the induction ports.

In a preferred practical embodiment, the hollow element comprises a cylindrical gauze sleeve having the mounting means at or adjacent its upper end and a closed, solid bottom end.

While such a simple cylindrical sleeve is capable of effecting some fuel saving, the efficiency of the device is markedly improved when the sleeve has a transverse wall of fine mesh gauze intermediate its top and bottom ends, and when the solid bottom end of the gauze sleeve is domed towards the interior of said sleeve. The transverse gauze wall preferably has a diametrical depression, which may conveniently have a cross-section normal to its length in the shape of a truncated cone.

The mounting means preferably comprises a peripheral flange at the upper end of the sleeve.

This flange may be apertured to enable mounting of the device with the usual carburettor mounting bolts.

In the Accompanying Drawings Figure 1 is a schematic diagram of a typical carburettor intake system in a motor vehicle; Figure 2 shows the intake system modified by inclusion of the fuel economy device of this invention; Figure 3 shows the fuel economy device in axial section; Figure 4 is a plan view of a transverse wall in the device; and Figure 5 is a plan view of a solid base wall in the device.

Figure 6 illustrates an alternative form of the device shown in Figures 3-5.

Description of Embodiment Referring to Figure 1, the reference 10 designates a carburettor body having a base 11 fixed by bolts 12 to an induction manifold 13. The arrow 14 indicates the prevailing air suction in operation, and the arrows 1 5 indicate the fuel/air flow exiting from the carburettor 10 into the induction manifold 1 3. Usually, this fuel/air flow will contain fuel in the form of liquid particles or globules which are liable to bewasted. Ideally, the induction manifold 13 would supply only finely atomised or vapourised fuel to the induction ports. The arrows 1 6 represent the fuel/air supply to these induction ports.

Figure 2 shows the same carburettor intake system fitted with the device 20 of this invention, which comprises a cylindrical sleeve 21 of fine mesh gauze having at its upper end a peripheral flange 22 by which the sleeve is mounted in position. The cylindrical gauze sleeve 21, when mounted in position, projects into the induction manifold, and in no way interferes with the action of the carburettor butterfly throttle (not shown) which is opened and closed by use of the accelerator pedal. The arrows 17 represent the flow of fuel/air mixture through the device 20.

The device 20 is shown in more detail in Figures 3 to 5. The cylindrical gauze sleeve 21 has a closed, solid bottom end 23 remote from its upper end mounting flange 22. This solid base of the sleeve is domed upwardly as shown in Figure 3; the exact form of the doming will be clear from Figure 5. The device also has a transverse wall 24 of fine mesh gauze intermediate the top and bottom ends of the sleeve 21, which transverse wall has a diametrical depression 26. The form and shape of this depression 26 will be clear from Figures 3 and 4.

The relative dimensioning of the device as shown in the drawings has little significance, as the device will be manufactured in a shape and size specifically to suit the carburettor intake system of each particular model of motor vehicle.

Furthermore, the device may be made of any convenient material which is not subject to heat deterioration.

In operation, fuel wastage is avoided because the device permits substantially only finely atomised or vapourised fuel to be fed to the induction ports. In particular, it is to be noted that any liquid fuel particles or globules which penetrate to the lower side of the transverse gauze wall 24 or reform below said wall will fall on to and then run off the domed solid base 23 to the edge thereof, thereby to be atomised and vapourized when blown through the cylindrical gauze sleeve 21.

The effectiveness of the device has been tested on Ford and Skoda vehicles. A Ford Cortina car, with a 1 500 c.c. engine and standard carburettor, was tested over a period which included urban and longer distance motoring, both without the fuel economy device and with it, and improvements in fuel economy of the order of 8 to 12% for urban driving and 10 to 15% for longer distance motoring were attained with the device fitted. This fuel saving was the combined result of less choke demand when starting, especially in urban use, and less accelerator pressure demand to maintain vehicle speed, especially in longer distance motoring. The device was also found to give the benefit of more even running and smoother acceleration during driving. A skoda car, with an engine of slightly smaller capacity and a square based carburettor, showed similar results, with very marked reduction in choke demand when the economy device was fitted. In both cases, adjustment of the slow running idling condition was necessary when the fuel economy device was added.

Various modifications of the described embodiment are possible within the scope of the invention, especially as to the shape and form of the hollow gauze-walled element.

Referring to Figure 6, an alternative form of the device involves elongating the trough/diametrical depression 26 in which event the domed base 23 may be dispensed with.

Claims

1. A fuel economy device for a petrol engine which comprises a hollow element having a wall of fine mesh gauze, and means for mounting said element at the base of the carburettor with said element projecting into the induction manifold in use to receive into its interior the fuel/air flow exiting from the carburettor and to transmit into the induction manifold through its gauze wall only fuel which is in finely atomised or vapourised form.

2. A device according to claim 1 , wherein said hollow element comprises a cylindrical gauze sleeve having the mounting means at or adjacent its upper end and a closed, solid bottom end.

3. A device according to claim 2, wherein the sleeve includes a solid bottom end which is domed towards the interior of said sleeve.

4. A device according to claim 2 or claim 3, wherein said cylindrical gauze sleeve has a transverse wall of fine mesh gauze intermediate its top and bottom ends.

5. A device according to claim 4, wherein said transverse gauze wall has a diametrical depression.

6. A device according to claim 5, wherein said diametrical depression has a cross-section normal to its length in the shape of a truncated cone.

7. A device according to any of claims 2 to 6, wherein said mounting means comprises a peripheral flange at the upper end of the sleeve.

8. A fuel economy device substantially as described with reference to the accompanying drawings.

9. A petrol-engined motor vehicle fitted with the fuel economy device of any of claims 1 to 8.