AU669362B2

AU669362B2 - Improvement to carburettors

Info

Publication number: AU669362B2
Application number: AU39945/93A
Authority: AU
Inventors: E A De Silva Wijeyeratne
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-06-01
Filing date: 1993-06-01
Publication date: 1996-06-06
Anticipated expiration: 2013-06-01
Also published as: AU3994593A

Description

P/00/011 mIlso Rogulation 3.2

AUSTRALIA

Patents Act 1990 r 1k

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "IMPROVEMENT TO CARBURETTORS" The following statement is a full description of this invention, including the best method of performing it known to me:- Field of the Invention SThis Invention relates to improvement of Carburettors for use in n.. I Background and Problems with the 'Prior Art' t o. I Due to lack of desired efficiency of Carburettors, manufacturers are now changing tc other devices for supplying Internal combustion are expensive, complicated and more difficult to service.

At present Carburettors of conventional design have only one Mainjet per Venturi, where the Mainjet is connected by a Main passage to a Main nozzle opening into the Venturi which supplies a spray of fuel that mixes with air in the Venturi to provide the engine with a mixture of fuel and air.

In addition, the fuel spray supplied by the Main nozzle also contains air bubbles provided by the airbleed opening into the Main fuel passage.

Having a single Mainjet for each Venturi is disadvantageous because Mainjet sizes get larger as engines require more fuel for increased engine outputs and as the Carburettor Mainjet size gets larger the Main nozzln fed by the Mainjet and opening into the Venturi and supplying the Venturi with fuel does not provide a fine spray of fuel that is desired but instead supplies fuel in larger particles or droplets which would be present in the fuel/air mixture provided to the engine resulting in a higher fuel consumption and a greater level of pollution from exhaust gases.

Statement of the Essential Features of the Invention The objective of this Invention is to overcorra the problem of unatomised fuel being mixed with air in each Venturi of a Carburettor with Throat controlled by Throttle valve downstream of the Venturi.

This is achieved by terminating the use of a single Mainjet currently used with a single Main passage and single Main nozzle that opens into each Venturi and replacing the jingle Mainjet with two or more smaller Mainjets of equal size to supply metered fuel to each Venturi.

:Ff Here two or more Mainjets are used for each Venturi and each Mainjet is connected by a separate Main passage with Airbleed to a separate Main

S

nozzle opening into the Venturi and due to its smaller size each Mainjet would permit a more efficient spray of atomised fuel from each of the Main nozzles, which mixes with air and forms a uniform fuel/air mixture for a more complete conmbustion process in the engine.

As a result of the Improvement there is greater efficiency by lesser Fuel consumption leading to a greatly reduced level of Pollution from exhaust gases and in addition a Carburettor with such improvements would be a much cheaper solution for car manufacturers rather than a fuel injection system particularily in the economy car range.

To assist with understanding the Invention, reference will now be made to descriptions in Examples to DESCRIPTION OF EXAMPLES OF THE INVENTION EXAMPLE (1) Improvement to a Carburettor having the following:- 2- Venturis 2- Throats 2- Throttle Valves The Improvements are as follows:- 2- Mainjets of equal size (for Venturi No.l fed by fuel from fuel bowl) 2- Main fuel passageswith Airbleed (for Venturi No.l, and each Main fuel passage connecting one Mainjet to one Main fuel nozzle) 2- Main fuel nozzles (opening into Venturi No.l) 2- Mainjets of equal size (for Venturi No.2 fed by fuel from fuel bowl) 2- Main fuel passages with Airbleed (for Venturi No.2, and each Main fuel passage connecting one Mainjet to one Main fuel nozzle) 2- Main fuel nozzles (opening into Venturi No.2)

NOTE

Items in equal quantities but a minimum of two of each of (f) Items g in equal quantities but a minimum of two of each of 9 (i) Quantities of Items may vary from those of Items (h) further described in Example and Example EXAMPLE (2) Improvement to a Carburettor having the following:- 2- Venturis 2- Throats 2- Throttle Valves The Improvements are as follows:- 3- Mainjets of equal size (for Venturi No.1 fed by fuel from fuel bowl) 3- Main fuel passages with Airbleed (for Venturi No.l, and each Main fuel passage connecting one Mainjet to one Main fuel nozzle.) 3- Main fuel nozzles (opening into Venturi No.l) 2- Mainjets of equal size (for Venturi No.2 fed by fuel from fuel bowl) 2- Main fuel passages with Airbleed (for Venturi No.2, and each Main fuel passage connecting one Mainjet to one Main fuel nozzle) 2- Main fuel nozzles (opening into Venturi No.2) EXAMPLE (3) Improvement to a Carburettor having the following:- 2- Venturis 2- Throats 2- Throttle Valves 20 The Improvements are as follows:- 2- Mainjets of equal size (for Venturi No.1 fed by fuel from fuel bowl) 2- Main fuel passages with Airbleed (for Venturi No.1, and each Main fuel passage connecting one Mainjet to one Main fuel nozzle) 2- Main fuel nozzles (opening into Venturi No.1) 3- Mainjets of equal size (for Venturi No.2 fed by fuel from fuel bowl) 3- Main fuel passages with Airbleed (for Venturi No.2, and each Main fuel passage connecting one Mainjet to one Main fuel nozzle) 3- Main fuel nozzles (opening into Venturi No.2) 5 EXAMPLE (4) Improvement to a Carburettor having the following:- 1- Venturi 1- Throat 1- Throttle Valve The Improvements are as follows:- 2- Mainjets of equal size (fed by fuel from fuel Bowl) 2- Main fuel passages with Airbleed (and each Main fuel passage connecting one mainjet to one Main fuel nozzle) 2- Main fuel nozzles (opening into Venturi)

NOTE

Items in equal quantities but a minimum of 2 of each of further described in Example EXAMPLE Improvement to a Carburettor having the following:- 1- Venturi "W 1- Throat 1- Throttle Valve The Improvements are as follows:- 3- Mainjets of equal size (fed by fuel from fuel Bowl) 3- Main fuel passages with Airbleed (and each Main fuel passage connecting one mainjet to one Main fuel nozzle) 3- Main fuel nozzles (opening into Venturi)

Claims

1. A carburettor for an internal combustion engine, the carburettor comprising a float chamber in fluid communication with at least one venturi characterised in that the float chamber has a plurality of equally sized main jets each coupled to a separate main nozzle discharging into the venturi, each main nozzle being connected to each main jet by a separate main passage.

2. A carburettor according to claim 1 characterised in that three main nozzles are provided in the venturi coupled to three equally sized main jets in the float chamber via separate main fuel passages.

3. A carburettor according to either claim 1 or claim 2 characterised in that the float chamber is in fluid communication with two venturis, each venturi having a plurality of main nozzles.

4. A carburettor according to claim 1 substantially as described herein with reference to the examples. DATED THIS 4TH DAY OF APRIL 1996. E A DE SILVA WIJEYERATNE By its Patent Attorneys: GRIFFITH HACK CO Fellows Institute of Patent Attorneys of Australia stalf/aelkeep/specY39945.93-1 4.4.96 ABSTRACT An Improvement to Carburettors is disclosed. The Improvement consists of having Two or more Mainjets for each Venturi of the Carburettor where each Mainjet would provide metered fuel through a separate Main Passage having an Airbleed and each Main Passage would be connected to a separate Main Nozzle opening into the Venturi. Each Mainjet would be of equal size and enable a spray of atomised fuel from each of the Main Nozzles to combine with air in the Venturi to supply the required fuel/air mixture for the engine. An Improvement to Carburettors as described in Examples to of the Complete specification. 0 *o0 *i