FORM2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
PROVISIONAL SPECIFICATION
(See section 10; rule 13)

. Title of the invention. -

MULTI CYLINDER AUTOMOTIVE DIRECT INJECTION DIESEL ENGINE ASSEMBLY

2. Applicant(s)
(a) NAME :
(b) NATIONALITY
(c) ADDRESS:

Greaves Cotton Ltd.,
An Indian Company
Light Engines Group, J-2, MIDC Chikalthana, Aurangabad-431 210.

3. PREAMBLE TO THE DESCRIPTION
The following specification describes the invention


FIELD OF THE INVENTION
The present invention rej.ates to a multi cylinder automotive direct injection diesel engine assembly. More particularly, the invention is concerned about a two cylinder four stroke automotive direction injection diesel engine meant mainly for small commercial vehicles wherein the direct ignition engine would provide improved power transmission efficiency. In more particular, the invention is concerned about a two cylinder four stroke automotive direct injection engine assembly having feature of even firing at the time of fuel injection in the combustion chamber. The engine of the present invention also finds it:.* application in gensets, tractors, marine and pumpsets. Also the direct ignition IC engine of the present invention finds its application in large commercial vehicles (LCV).
BACKGROUND AND THE PRIOR ART
Most of automotive diesel engines are four-stroke cycle engine, with a compression heating ignition system, rather than needing a separate ignition system. This variation is calLed the diesel cycle. In the diesel cycle, diesel fuel is injected directly into the cylinder so that combustion occurs at constant pressure. The piston movement in four stroke cycle are explained below.
1. Intake(suction stroke)
2. Compression stroke
3. power (expansion stroke)
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4. Exhaust stroke
A?, their name impli es, operation of a four stroke internal combustion engines have 4 basic steps that repeat with every two revolutions of the engine:
Intake
Combustible mixtures in impinged in the combustion chamber.
Compression
The mixtures is placed under pressure.
Combustion/Expansion
The mixture is burnt almost invariably. The hot mixture is expanded, pressing on and moving parts of the engine and
performing usefu1 work.
Exhaust
The cooled combustion products are exhausted into the atmosphere
Al] internal combust ion engines depend on the exothermic chemical process of combustion reaction of a fuel, typically with oxygen from the air and the diesel fuel is injected through injection system. The combustion process typically results in the production of a great quantity of heat, as well as the production of steam and carbon dioxide and other chemicals at very high temperature. The temperature reached is determined by the chemical makeup of the fuel and oxidizers. The most common modern fuels are made up of hydrocarbon and are derived mostly from aromatic
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compounds (petroleum). Diesel engine runs with air mixed with diese] fuel.
Diesel Ignition Process
DJ eseJ engi nes rely solely on heat and pressure created by the engine in its compression process for ignition. The compress!on level that occurs is usually twice or more than a gasoline engine. Diesel engines will take in air only, and shortly before peak compression, a small quantity of d.iesel fuel is sprayed into the cylinder via a fuel injector that allows the fuel to instantly ignite.
Diesel engines advantages
• They burn less fuel than a gasoline engine performing the same work, due to the engine's high efficiency and diesel fuel's higher energy density than gasoline,
• They have no high-tension electrical ignition system resulting in high reliability.
• The life of a diesel engine is generally about twice as long as that of a gasoline engine due to the increased strength of parts used, also because diesel fuel has better lubrication properties than gasoline.
• Diesel fuel is considered safer than gasoline in many applications.
• They generate less heat in cooling and exhaust.
• The carbon monoxide content of the exhaust is minimal

Commonly two cylinder 1C engines are used for small commercial vehicles (SCV) and such two cylinder engine of TATA ACE lor SCVs are available in the market. TATA ACE engine is an indirect injection internal combustion engine having pre-combustion chamber rated at 3200 rpm maximum engine speed. One of biggest disadvantages of this type of indirect injection engine is inferior fuel consumption compared to direct injection engine of the same capacity. This engine is also having less torque and power and thereby will have less acceleration and poor output efficiency.
US6,082,327 teaches a direct-injection spark-ignition four-stroke internal-combustion engine which includes a combustion chamber delimited by a piston, a cylinder and a cylinder head, an intake pipe associated with an intake valve, an exhaust pipe with which an exhaust valve cooperates, an ignition element and a fuel injection element. The fuel injection element is situated close to the ignition element, in the same half of the cylinder head as the exhaust valve, the half cylinder itself being placed toward the front of the vehicle. Fuel injection element can be placed below the ignition element.
US7,188,589 teaches in a direct injection internal combustion engine, a fuel injection valve of adjacent cylinders are inclined at different angles from each other in directions perpendicular to a cylinder arrangement oirection in which the cylinders are arranged. Besides, the fuel injection valve and the spark plug of at least one of the cylinders are inclined at different angles from each
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other in directions parallel to the cylinder arrangement drection.
US 7,234,4 31 teaches a direct-injection internal combustion engine and a combustion method therefore in which fuel injection timing of a fuel injection valve is so configured that (a) the fuel inverted from a cavity in a crown portion of a piston reaches proximity to the discharge electrode portion of a spark plug later than the time of ignition or (fc<) fuel :i nj ect ion by the fuel injection valve is completed at approximately the same time of ignition. There is no risk of rich combustion at the discharge electrode portion due to the mixed fuel-air mass having a high fuel density, and consequently problems such as wear on the spark plug or smoke generation can be avoided.
US5117793 describes fuel injection system and method for a fuel inj ected engine of the multi cylinder type for minimizing variations in crankshaft speed due to variations in individual cylinder to cylinder firing. These variations ate compensated for by changing the fuel injection and specifically the duration of the fuel injection. The engine speed is measured for each cylinder either by the time required to reach top dead center from a predetermined angle, the time to reach bottom dead center from a predetermined angle, or from the average speed.
US4499876 describes method and apparatus for controlling the injection of fuel into an internal combustion engine having a plurality of unit injectors which are each controllable separately for each cylinder of the engine. The occurrence of a malfunction in the fuel injection of
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each of the injectors is discriminated in accordance with the engine operating condition detected by sensors whereby when the presence of a malfunction in the injector of any one of the cylinders is discriminated, the operation of the engine is not. stopped but the operation is continued in a fciult mode of operation so that the injection of fuel from the maIfunction.ing injector is stopped and the injection of fuel from the injector of at least one of the other cylinders is stopped or its number of events of injection is decreased from the standpoint of balance in the generation of engine power output.
Thus there is a need to provide for a two cylinder itiulti stroke automotive direction injection engine meant mainly foe smalJ commercial vehicles (SCVs) and large commercial vehicles (LCVs) wherein the direct ignition engine would provide improved power transmission efficiency.
The present inventors have found that a two cylinder multi stroke automotive direction diesel injection engine with improved power transmission efficiency can be achieved by way of an even firing order in the combustion chamber of the engine. Said firing order being established by way of a control means for advancing of start of fuel injection timing so as to reduce emission. Further it has been found by the inventors that the engine when inter-engaged and located at a certain inclination from the horizontal, it can work upto vertical configuration.
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OBJECTS OF THE INVENTION
Thus one object of the present invention is to provide a two-cylinder raulti stroke automotive direct injection diesel engine assembly with improved power transmission ef ficiency.
Another object of the present invention is to provide a two cylinder multi stroke automotive direct injection diesel engine assembly having even firing order during fuel injection in the combustion chamber.
Another object of the present invention is to provide a two cylinder multi stroke automotive direction injection engine with reduced mechanical and acoustic vibrations.
Another object of the present invention is to provide a two cy]inder multi stroke automotive direction injection engine such that without much modification an unit pump base common rail (UPCR) can easily be adapted for further stringent emission norms.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1 illustrates an exploded view of assembly of water pump and vacuum pump in crankcase.
Figures 2(a) and 2(b) illustrate schematic diagram of water pump assembly.
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F.i gure 3 illustrates an isometric view of water pump assembly.
F..,gure 4 illustrates an exploded view of vacuum pump assembly.
Figure 5 illustrates internal details of vacuum pump,
Fi gure 6 i1lustrates a schematic diagram of vacuum pump,
Figure 7 illustrates a cross sectional view and assembly of crankshaft and balancer shaft in crankcase.
Figure 8 illustrates an exploded view of balancer shaft and
crankshaft,
Figure 9 illustrates a schematic diagram of balancer shaft.
Figure 10 illustrates a schematic diagram of even firing crankshaft.
Figure 11 illustrates an isometric view of timer assembly.
Figure \7 illustrates a transverse sectional view of timer assembly.
Figure 13 illustrates a cross sectional view of timer assembly.
Figure 1.4 illustrates a comparison of firing intervals of even and uneven firing.
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DETAILED DESCRIPTION OF THE PRESENT INVENTION
The two cylinder or multiple cylinder engine assembly of the present inventjon is a direct injection diesel engine located at an inclination of 15 degree from the horizontal arid which can work upto vertical configuration. The height of the engine is so adjusted that it can be comfortably packaged either at the rear side of a cargo vehicle below the rear deck or in front side of the vehicle. The design of the engine is made in such a way that without much modification an unit pump base common rail (UPCR) can easily be adapted for further stringent emission norms. The engine primarily is designed for application of alight transportation/cargo vehicle upto the GVW of 1.5 ton. But the tonnage as described hereinabove is not a restriction to the present invention. The engine in its present concept as described so far and described hereinbelow can be extended to higher tonnage vehicles which will still be comprises in the true spirit of the present invention.
The engine assembly of the present invention comprises plurality of pumps which includes water pump means which is operatively coupled to a vacuum pump housing. The water pump is gear driven and comprises centrifugal impeller which is driven by engine crankshaft through gear drive. The water pump comprises spline shaft which in turn is coupled to the vacuum pump which is used for brakes and is packaged inside the engine. The vacuum pump is an integral part of the engine assembly and has eccentric segments which are running extension of water pump spline shaft.
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Orie embodiment of the present invention describes a shaft means adapted for reducing vibrations originating from the operation of the engine or any other acoustic vibrations if any generated. The shaft means is a balancer shaft which rotates in opposite direction to crankshaft* Balancer shaft design is incorporated to reduce high speed and low load vibrations of engine and it will give benefit to torque recoil.
In another embodiment the engine assembly of the present invention comprises even firing crankshaft in which the firing of each cylinder is separated from its predecessor by same angular travel of the crankshaft i.e. 360° phase di iference.
Benefits of even firing :
• Equal air distribution to each cylinder allows increased overall fuel delivery for increased torque output.
• EGR distribution will be more even affording reductions in emissions, it will help in NOx & PM trade-off.
• It also eliminates low frequency vibration component
Advantages :
i. Suitable turbo charging by way of even firing in two cylinder four stroke engine;
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2. 15° inclination of the engine from the horizontal so that the engine can also work up to vertical configuration;
3. Height adjustment is such that the engine assembly can be suitably packaged either at the rear side of a cargo vehicle below rear deck or in front side of the
vehicle;
4. Design of the engine is such that without much
modification an unit pump base common rail can easily
be adapted for further stringent emission norms.
Dated this the 26th day of May 2009
Abhishek Sen
Of S Majumdar & Co.
Applicant's Agent
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