Internal-combustion engines – Charge forming device – Gaseous fuel and air mixer
Patent
1997-11-10
1999-03-30
Moulis, Thomas N.
Internal-combustion engines
Charge forming device
Gaseous fuel and air mixer
F02M 2104
Patent
active
058875743
DESCRIPTION:
BRIEF SUMMARY
FIELD OF INVENTION
This invention relates to a system for injection of liquid fuel into an internal combustion engine and more particularly to injection of a low boiling point liquid into such engines.
The invention is particularly directed towards the injection of Liquefied Petroleum Gas (LPG) or Compressed Natural Gas (CNG) into internal combustion engines.
BACKGROUND OF THE INVENTION
A problem with such fuels when used in a liquid state is that because of their very low boiling point they will tend to vaporise in fuel lines unless a sufficient pressure over the vapour pressure at any expected temperature is provided.
In Australian Patent No. 647561 a fuel injection system is disclosed in which liquid LPG is injected into an inlet manifold adjacent to the engine. This region of the engine can get very hot and as such even with excess flow of fuel there can be a problem with vaporisation of fuel. It is desirable therefore that easily vaporisable fuels are injected some distance away from the engine.
It is an object of this invention to provide a fuel injection system for such fuels and in one particular embodiment to modify an internal combustion engine fuelling system adapted to operate on injected petrol so that it can also operate on LPG or CNG liquid injection.
The invention, however, is not particularly directed to this adaptation but is generally directed to a modified fuel injection system.
BRIEF DESCRIPTION OF THE INVENTION
In one form therefore the invention is said to reside in a fuel injection system for injecting liquid LPG or CNG into an air inlet duct of an internal combustion engine, the fuel injection system including an adaptor ring which is adapted to be mounted into the air intake duct for the engine upstream or downstream of the throttle valve in the inlet duct so as to allow air flow therethrough, at least one pod mounted into the adaptor ring, each pod including a fuel inlet, a fuel outlet and a hollow space within the pod into which the fuel inlet and fuel outlet open and a liquid fuel injector sealably mounted into the or each pod, liquid fuel supply lines to the pod and from the pod and means to allow fuel to enter the injector from the hollow space within the pod to be injected therefrom into the inlet duct and an injector control arrangement acting upon engine parameters and demand parameters to control the or each injector to inject liquid fuel into the engine as required.
It will be noted that in this embodiment the LPG or CNG is injected into the inlet manifold near the throttle valve which is at some distance from the actual engine. This has two particular advantages.
First of all the region of injection is not such a hot part of the engine compartment as the engine block so that the injectors and the fuel lines can be placed further away from the engine and therefore do not get so much heating and avoid the heat soak conditions which may cause vaporisation.
A second advantage is that by injecting the fuel some distance from the engine and allowing it to flow past the throttle valve along the inlet manifolds to the various inlet valves of the engine a greater time is allowed for full vaporisation of the fuel which in turn will allow better combustion.
A third advantage is that there is considerable simplicity of installation of such a system where it is not necessary to modify the inlet manifold to any great extent nor touch other injectors such as petrol injectors already existing on the engine. It is only necessary to mount the adaptor ring into the air intake duct either before or after the throttle valve.
It will be noted that such a system can be fitted to an engine at the time of manufacture or may be fitted later.
The or each pod may comprise a body having a top, a bottom, at least one side and an aperture extending through the body from the top to the bottom, the fuel inlet and the fuel outlet being on the side of the pod and the aperture defining the hollow space within the pod into which the fuel inlet and fuel outlet open, the opening of the aperture at the
REFERENCES:
patent: 5291869 (1994-03-01), Bennett
Energy Research and Development Corporation
Moulis Thomas N.
LandOfFree
Liquid fuel injection system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid fuel injection system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid fuel injection system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1205753