Internal-combustion engines – Charge forming device – Fuel injection system
Reexamination Certificate
1996-02-27
2004-02-10
Miller, Carl S. (Department: 3747)
Internal-combustion engines
Charge forming device
Fuel injection system
C123S469000
Reexamination Certificate
active
06688288
ABSTRACT:
This invention relates to engines and engine propelled vehicles and particularly to relatively small multi-cylinder engines such as those commonly used in personal watercraft such as jet skis and jet boats. It is envisaged that the invention is equally applicable to other “personal-type” small engined vehicles such as snow-mobiles and small all-terrain vehicles.
As a result of the increasing concern in regard to air pollution by exhaust gases from internal combustion engines, legislation is beginning to be introduced or made more stringent in some countries relating to the level of emissions contained in exhaust gases from the engines of a range of relatively small vehicles. This is in addition to the existing legislation relating to the emissions from cars and trucks and like large vehicles.
Further, having regard to the size and weight of the engine of small vehicles, it is important to design such engines so as to occupy the smallest possible space within the vehicle and, as a consequence, reduce the overall size and weight of the vehicle. At the same time, such engines must be able to develop a relatively high power output in order to obtain a level of performance acceptable to the purchasing public.
In order to achieve relatively high power outputs together with low exhaust emissions, it has in some cases been necessary to avoid the use of the more conventional carburettor or manifold injected engines and to adopt a direct injected engine in order to achieve these desired high power outputs and low exhaust emissions. However, such engines typically require additional componentry which can result in an increase in the space requirement of the engine within the vehicle and thus it is important to obtain an engine layout which is relatively compact.
It is therefore the object of the present invention to provide an engine particularly suitable for use in small vehicles including personal watercraft which is of minimum physical dimensions and an acceptable manufacturing cost.
With this object in view there is provided, according to one aspect of the invention, an in-line multi-cylinder internal combustion engine having on one side of the cylinder block an air induction system and on the opposite side an exhaust system, each extending generally in the direction of the length of the engine and both said systems extending beyond the plane of a cylinder head of the engine, a fuel rail extending in the direction of the length of the engine and mounted on the cylinder head to be located between the air induction system and said exhaust system, said fuel rail overlying and being in fuel transfer communication with respective fuel injection units located in the cylinder head, and each said fuel injector communicating with a respective cylinder of the engine.
Preferably, a spark plug is mounted in each cylinder to enter the cylinder at a level below the top of the fuel rail and to project from the cylinder head to one side of the fuel rail. The spark plugs may be arranged in the cylinder head at a location between the engine exhaust system and the fuel rail. Conveniently, the fuel rail is configured so as to provide sufficient clearance on the exhaust system side thereof, when mounted on the cylinder head, to enable the spark plugs to be appropriately arranged within the cylinder head on the exhaust system side thereof. Alternatively, for different engine configurations, the fuel rail may be configured to allow for appropriate location of the spark plugs on the air inlet side of the engine.
Preferably, the fuel injector units are of the type wherein the fuel is entrained in a compressed gas for delivery to the engine, and the fuel rail includes both a passage for the conveyance of fuel and a further passage for the conveyance of the gas, normally air. Preferably, the fuel rail also has incorporated thereon a fuel pressure regulator and a gas pressure regulator. These regulators are conveniently mounted on the fuel rail on the side thereof remote from the spark plugs. More particularly, the regulators are arranged on the fuel rail at a location immediately adjacent the air induction system.
Conveniently, the fuel rail is configured such that when mounted on the cylinder head, the regulators mounted thereon are located adjacent the air induction system such that sufficient clearance is provided on the exhaust side of the cylinder head for the spark plugs to be arranged therein. In this regard, the air induction system may be able to be slightly angled so as to enable the appropriate location of the fuel rail on the cylinder head. Alternatively, for an alternative location of the spark plugs, the exhaust system may be able to be slightly angled for similar reasons.
Preferably, the fuel rail is arranged such that an air inlet thereto is located at an opposite side to a fuel inlet thereto. Conveniently, the air and fuel inlets are arranged at opposing ends of the length of the rail with the air inlet being located adjacent that end of the engine where a drive-shaft projects from the cylinder block. It is however to be noted that other arrangements for the location of the fuel and air inlets on the rail are possible such as, both at the same end on the length thereof. Preferably, the fuel inlet is arranged to correspond with that end of the engine adjacent which a fuel pump is located.
Preferably, the air induction system is configured to comprise one air flow control means for regulating the amount of air to each of the cylinders of the engine. Whilst it is possible to provide an individual air flow control means for each cylinder of the engine, each housed in an individual air conduit of the air induction system as is well known, for example, personal watercraft engines, the provision of a single air flow control means enables significant simplification of the air induction system. This in turn reduces the component cost thereof as well as contributing to a reduced overall size, weight and complexity of the engine.
Where the engine is of the type incorporating a fuel injector unit which delivers the fuel entrained in a gas to a combustion chamber of the respective cylinders, it is also necessary to provide an on-board source of compressed gas, typically air, for this purpose. The preferred source of compressed air is typically from an engine driven compressor. Conveniently, the compressor is driven by the engine via a portion of the engine crankshaft the projects from one end of the engine via a pulley or gear mounted thereon or on the drive-shaft coupled thereto, or by an appropriately provided surface of a coupling between the crankshaft and drive-shaft of the compressor. Accordingly, it is preferable to locate such a compressor on the engine such that it corresponds to an end of the engine wherein it is possible to conveniently couple the drive-shaft of the compressor to the engine crankshaft or a drive-shaft connected thereto. Some engines may have a camshaft to effect operation of the valves of the engine, and/or a balance shaft and the compressor may be suitably coupled to the camshaft or balance shaft to be driven thereby.
In an engine constructed so that a portion of the exhaust system projects beyond the upper extremity of the engine block at the end where the drive-shaft is located, and is adjacent an upper end of the engine block or the cylinder head thereof, it is preferable for the compressor to be mounted below the level of that portion of the exhaust system so that the compressor does not increase the overall size or length of the engine. Further, it is appropriate for the delivery port of the compressor to be located in the upper portion of the compressor when mounted so that the length of the conduit carrying the air to the fuel rail is minimised. That is, it is preferable to mount the compressor at that end of the engine which corresponds to the end where the drive-shaft thereof is located and also so as to correspond with the air inlet of the fuel rail. In this way, the length of the air line connecting the compressor delivery port and the air inlet to the rail is kept
Gulvin Paul Thomas
Houston Rodney Alexander
McNiff Martin Peter
Shawcross David
Miller Carl S.
Orbital Engine Company (Australia) PTY Limited
Rothwell Figg Ernst & Manbeck P.C.
LandOfFree
Internal combustion engines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Internal combustion engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Internal combustion engines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3349056