|Title of Invention||
A TWIN BARREL CARBURETOR SYSTEM FOR PETROL ENGINE
|Abstract||The invention relates to a twin barrel carburetor system for petrol engines. it consists of two main orifices to meter the fuel flow and two venturis for allowing the air to pass through the carburetor systemThe invention is charactrised in that a primary air pressuring duct and a secondary air pressurizing duct being provided in the path of air flow befor the venturi of the twin barrel carburetor system.The aforesaid air ducts are intended to neutralise acute pressure drop created at high speeds of the petrol engines.|
This invention in general relates to internal combustion engines. This invention in particular relates to a twin barrel carburetor system for petrol engines. These systems supply air and petrol mixture required for combustion in petrol engines.
Hitherto known Twin barrel Carburetor Systems comprise a venturi for generating fuel flow and an orifice to allow fuel to the venturi. The problem associated to prior art Twin barrel Carburetor System is that the air pressure drop at the venturi is non-uniform with respect to flow rate of air resulting in fuel flow not being in proportion to air flow.
This results in high rate of fuel consumption at part throttle (part load) operation of petrol engine.
The primary object of the present invention is to overcome this drawback associated with known Twin Barrel Carburetor Systems.
Another object of the invention is to have a uniform and constant air fuel ratio at all throttle positions of engine operations.
Yet another object of the invention is to develop a Twin Barrel Carburetor System which would give constant rate of flow of fuel in proportion to airflow effecting higher power development as compared to conventional system.
Yet another object is to develop a Twin Barrel Carburetor System which will be economical in fuel consumption and easily adaptable to any usual petrol engine.
In an embodiment of the invention by providing air ducts before the venturi, uniform pressure drop with respect to the flow rate of air is effectively achieved resulting in constant fuel flow in proportion to air.
The problem associated with choking of air at air ducts is obviated by providing grooves or slits in the pressurizing duct, which gives substantial improvement in the pressurizing effect thereby avoiding chocking of air.
The air pressurizing ducts are provided near the venturi thereby achieving uniform pressure drop with respect of rate of flow of air.
The Twin Barrel Carburetor System is mounted on the inlet manifold of a petrol engine.
Various other objects of the invention will be apparent from the ensuing description.
A twin Barrel Carburetor System for petrol engines comprising of two main orifices for metering the fuel flow and two Venturis for allowing the air to pass through the carburetor system characterized in that a primary air pressurizing duct and a secondary air pressurizing duct being provided in the path of air flow before the venturi of the Twin Barrel Carburetor system.
The invention will now be described with reference to the accompanying drawings where in the figure is as follows :
Fig 1. : Shows a sectional view of a Twin Barrel Carburetor system having air ducts, according to this invention.
Under normal working condition of the internal combustion Engine, when the speed of the engine is increased there is a corresponding drop in pressure at the Venturis. This results in that the engine draws more fuel (petrol) from the fuel tank at high speed. This results in uneconomical fuel consumption at high speed. The introduction of air duct and the placement of this air duct above the Venturis over comes this problem.
Basically a Twin barrel carburetor system consists of two main orifices with a flow nozzle leading upto the venturi to meter the fuel flow (8) & (9) and two Venturis (11) & (12) for allowing air to pass through the twin barrel carburetor system (13) Twin barrel carburetor system (13) always operates under negative pressure i.e., less than atmospherics pressure. The air ducts placed before the Venturis pressurizes the air that is passing through it to relatively higher side than the negative pressure (pressure drop) existing at the Venturis of the twin barrel carburetor system, effecting similarly both at primary circuit and secondary circuits of the twin barrel carburetor system, thus reducing the acute pressure drop created due to the high speed of the engine. As shown in fig. 1 of the drawing two air ducts (14) & (15) are placed above the Venturis (11) & (12) along the path of the main Air flow (10).
According to fig. 1 of the drawing the twin barrel carburetor system (13) comprises Venturis (11) & (12) for allowing air (16) to flow in to the twin barrel carburetor system. The twin barrel carburetor system further has two orifices (8) &(9) with nozzle leading to the Venturis to allow flow of fuel to the Venturis (11) & (12). Air pressuring ducts (14) & (15) are provided in the path of air (16). These ducts are provided before the Venturis (11) &(12) of twin barrel carburetor system (13). The aforesaid air ducts have slits or grooves (17). The twin barrel carburetor system (13) is fitted to the inlet manifold (18) of petrol engine (19). When the petrol engine is made to run, the twin barrel carburetor system starts from a closed throttle position (20) by opening the butterfly throttle valve (6) at the primary circuit (5) shown in open position (21) increased flow of air and fuel mixture takes place.
On opening the butterfly throttle valve (6) the twin barrel carburetor system begins to operate. After a certain suction pressure created by the engine (19) in the increased load or speed the secondary circuits (4) begins to operate when the depression chamber pulls the butterfly throttle valve (2) to open at the secondary circuit. Thus both primary circuit (5) and secondary circuit (4) starts functioning. The main air flow is divided when the primary and secondary circuits (5) &(4) are simultaneously working. The air ducts (14) &(15) pressurize part of the main air flow at the ventures (8) &(9). This enables generation of constant fuel flow (22) in proportion to air.
Therefore air pressurising duct (14) pressurizes the air flow at venturi (11) and air pressurizing duct (15) pressurizes further stream of air at venturi(12) under high air intake condition of the petrol engine thereby securing uniform air fuel mixture (23). This results in higher fuel efficiency compared to conventional twin barrel carburetor systems. Grooves or slits (17) are provided in air pressurizing ducts (14) & (15) giving substantial improvements in the air pressurizing effect thereby avoiding choking of air. Air ducts (14) & (15) are fastened to Venturis (11) & (12) along the main air flow (10).
The air duct is funnel shaped having slits / grooves on it. These slits/grooves are of varying dimensions. This varying dimension is to ensure to offset the choking of air. This is shown in Fig. 1. of the drawing.
It has been found that the flow rate of fuel at the venturi of the twin barrel carburetor system can be maintained constant in proportion to air flow if the pressure drop across the venturi is maintained uniform with respect to flow rate of air.
It has been experimentally verified that by maintaining the fuel flow constant in proportion to the air flow, the relatively high consumption of fuel due to increasing pressure drop at the Venturis during the part throttle operation of the petrol engine is nullified.
Further the emission of carbon-monoxide from the engine exhaust is reduced if chemically correct (stoichiometric) mixture level of fuel and air is maintained.
It has been verified experimentally that the air ducts are provided in the path of the air flow, the pressure drop across the Venturis is uniformly maintained with respect to the flow rate of air securing constant ratio of air-fuel mixture, resulting in higher fuel efficiency than obtained through conventional twin barrel carburetor systems.
The main advantages of the invention is that a uniform homogenous air fuel mixture is obtained.
Other advantages are as follows: -
(i) Less emission of carbon monoxide compared to conventional system.
(ii) Fuel economy at all speeds and loads of the engine.
(iii) The invented Twin Barrel Carburetor system is applicable to petrol engines in automobiles, generating sets, marine engines and propeller air craft reciprocating piston engines.
1. A twin Barrel Carburetor System for petrol engines comprising of
two main orifices for metering the fuel flow and two Venturis for
allowing the air to pass through the carburetor system characterized
in that a primary air pressurizing duct and a secondary air
pressurizing duct being provided in the path of air flow before the
venturi of the Twin Barrel Carburetor system.
2. A twin Barrel Carburetor system for petrol engines as claimed in
claim 1 where in grooves of slits are provided in the air pressurizing
3. A Twin Barrel Carburetor system for petrol engine as claimed in any
of the preceding claims wherein the air pressurizing ducts are
provided near the venturi.
4. A Twin Barrel Carburetor system for petrol engines substantially as
herein before described and illustrated by way accompanying
|Indian Patent Application Number||424/MAS/1999|
|PG Journal Number||26/2007|
|Date of Filing||16-Apr-1999|
|Name of Patentee||SHRI. SOMENA HALLI VENKATASESHACHAR JANARDAN|
|Applicant Address||# 980,12-A CROSS,35th MAIN, 1st PHASE, J.P.NAGAR, BANGALORE 560 078|
|PCT International Classification Number||F02B003/00|
|PCT International Application Number||N/A|
|PCT International Filing date|