EP0639709A1

EP0639709A1 - Fluid mixture control valve; carburettor

Info

Publication number: EP0639709A1
Application number: EP93670004A
Authority: EP
Inventors: Silvestre Dias Antunes
Original assignee: INSTITUTO DE SOLDADURA E QUALIDADE
Current assignee: INSTITUTO DE SOLDADURA E QUALIDADE
Priority date: 1993-07-23
Filing date: 1993-07-23
Publication date: 1995-02-22
Also published as: WO1995003486A1; AU7240394A

Abstract

Problems posed by liquid or gas fuels combustion pollution, requires that at any instant a better primary air-fuel mixture is needed. A non adequated excess-air factor will be the source for an incomplete combustion with formation of pollutants. In order to solve these problems a fluid mixture control valve that can be used as part of a carburettor as been invented.

The mixture valve invented, it is a mixture control valve controlling mixture of a fluid α on a second fluid β, and, it is composed by a set of two calibrated orifices [4] and [5], on a cilindrical tube [2], obturated by the rotative cilindrical pistons [1] and [3]. The fluid α flow (liquid ou gas) injected, will be dependent of angular position of the two pistons [1] and [3], and so, it will be a function of two independent control parameters.

As an application, it is also, patented, a carburettor for internal combustion engines, using the mixture valve [6] on primary-air flow condut (fluid β), controlling the fuel flow (fluid α). Mixture valve it is actuated by two cams [7] and [8], controlled respectively by butterfly valve [11] and by air-flow sensor [7].

Description

The invention relates to a mixture control valve controlling a fluid α flow (liquid or gas), in order to mix it with a second fluid β (liquid or gas), with or without state transition of any of the fluids. The control valve acts as a mixture control of fluid α flow with fluid β flow. An application, it is on controlling the primary air-fuel mixture, in combustion systems and/or in carburation systems on internal combustion engines, acting as a carburettor.
The mixture valve represented in exploded perspective in figure 1, and, sectionned in figure 2, it is constituted by a set of two calibrated orifices [4] and [5], on a cilindrical tube [2], the orifices are obturated by two rotative cilindrical pistons [1] and [3]. The pistons have a rotative displacement inside tube [2] and the profile cutted together with their displacement defines the pressure drop coefficient of each one of the sets rotative piston-orifice. So total pressure drop coefficient will be a function of angular position of the two pistons [1] and [3]. And the mixture control will be a function of those two independent parameters.
If cilinder [2] is placed on fluid β flow (liquid or gas), where we intend to control mixture with a second fluid α (liquid or gas) flow, it will be injected by mixture valve. Fluid α will be introduced at constant pressure, by an adequated tube on orifice [4], and comming out to mixture with fluid β (liquid or gas) on orifice [5]. The fluid α (liquid or gas) flow injected, will be a function of the angular position of the two pistons [1] and [3], and, will be a function of two independent parameters. So actuation on pistons will be mechanical, automated, motorized, and so on.
A typical application for the mixture valve corresponds to it's use on controlling the primary air-fuel mixture, in combustion systems and/or in carburation systems acting as a carburettor. So the fuel α flow will be controled on mixture with primary air β flow (see figures 3 and 4) in order to obtain a mixture α+β almost ideal in transients (during acceleration or desacceleration of internal combustion engines). One of the pistons will be actuated by engine accelerator [12], simulthaneously with butterfly valve [11], and the second piston will be actuated by sensor plate [7] measuring primary air flow, so we have a carburettor, that will provide at any instant an ideal primary air-fuel almost ideal (excess-air factor λ∼constant). So a better specific consumation so as less carbon monoxide and less hidrocarbonets will be present on exhaust gas. Exhaust gas will present a more homogeneous and regular composition.
On figures 3 and 4 we represent side vues of the carburettor, where mixture valve [10], placed on primary air flow (fluid β) controls fuel flow injected (fluid α), and it is actuated by two cams [9] and [6], one controlled by butterfly valve [11] and the second controlled by air-flow sensor [7].
The two cams [9] and [6] displacement are compensated by ressorts, not represented in figures, but acting in order to compensate acelerator force, so as air-flow force on air-flow sensor.

Claims

Mixture control valve controlling the mixture of two fluids, function of two independent control parameters. This is a mixture valve controlling the fluid α flow in a second fluid β flow, it is composed by a set of two calibrated orifices [4] and [5], on a cillindrical tube [2], obturated by two cillindrical rotative pistons [1] and [3]. The fluid α flow (liquid ou gas) injected, will be dependent from angular position of the rotative pistons [1] and [3], so it will be a function of two independent control parameters..
Control parameters will be the angular displacement of the cilindical pistons.
Internal combustion engine carburettor, based on an application of the mixture control valve [10] in claim 1. Mechanical control, based on two cams [9] and [6] will provide a primary air-fuel factor almost ideal, in transients (acceleration--desacceleration), cam [9] will be actuated simulaneously with butterfly valve [11] and cam [6] will be actuated by the air flow sensor [7].