FORM - 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE
Specification
(See section 10 and rule 13)
EQUIPMENT USED IN INTERNAL COMBUSTION ENGINES
KIRLOSKAR OIL ENGINES LIMITED
an Indian Company
of Laxmanrao Kirloskar Road, Khadki, Pune 411 003,
Maharashtra, India
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

Field of invention:
This invention relates to equipment used in internal combustion engines.
Particularly, this invention relates to fuel injection equipment used in internal combustion engines, typically diesel internal combustion engines.
Even more particularly, this invention relates to fuel injection equipment used in multi-cylinder internal combustion engines, typically multi-cylinder diesel internal combustion engines.
Background of invention: Introduction:
The internal combustion engine is a heat engine in which combustion occurs in a confined space called a combustion chamber. Combustion of the fuel charge inside a chamber causes a rapid rise in temperature and pressure of the gases in the chamber. The expanding gases are used to move a piston, turbine blades, rotor or the engine itself.
Internal combustion engines can be powered by any fuel that can be combined with an oxidizer in the chamber. Fuels used may include petrol, liquefied petroleum gas, vapourized petroleum gas, compressed natural gas, diesel fuel, JP18 (jet fuel), biodiesel, ethanol, methanol (methyl or wood alcohol), and hydrogen peroxide and the like.
Fuel injection equipment is required in a diesel IC engine to supply the desired amount of fuel under required conditions. For this purpose diesel engines use a fuel injection pump (FIP). The Fuel injection pump consists of a plunger
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and barrel assembly with a control mechanism for pressurizing and metering the amount of fuel entering the combustion chamber.
Fuel injection equipment must fulfill following requirements:
• It should deliver the exact amount of fuel required by the engine
depending upon speed and load on the engine.
• It should deliver the fuel at sufficiently high pressure to have better
atomization and combustion of fuel.
• It should deliver the fuel at correct time to facilitate the combustion of the fuel.
• For a Multi-cylinder engine fuel injection equipment should deliver the fuel in precise manner to all the cylinders depending upon the firing order of the engine.
Prior Art:
The conventional fuel pumps have a typical construction, which limits the capacity as far as quantity of fuel injected into pump and injection pressure developed inside the pump. A single cylinder IC engine uses one fuel pump. The fuel pump is generally fitted into the crankcase. This type of arrangement does not have any design limitation as far as pressure and quantity of fuel injected is concerned. The fuel pump itself is designed for the required pressure. The crankcase provides the necessary support to the individual fuel pump.
Figure 1 illustrates every component of the conventional fuel pump according to the prior art. Construction details of a conventional fuel pump:
• The fuel pump consists of a plunger and barrel assembly, which
pressurizes the fuel to the desired level.
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• This plunger and barrel assembly is fitted into a housing.
• A camshaft is used to give a predetermined motion to the plunger through a spring and roller tappet arrangement.
• The camshaft is supported on the bearings, which are located in the housing.
• A toothed control rack is connected to the plunger through a toothed sleeve. The linear motion of the rack is converted into the rotary motion of the plunger, which is required to control the amount of fuel delivered to the engine.
• Fuel is supplied through a common gallery to all the plunger barrel assemblies.
• A feed pump is used to generate the required pressure in the fuel gallery.
• High-pressure pipes are used to supply the fuel from fuel pump to the injector.
Figure 2 illustrates the fuel circuit usually employed in a conventional diesel IC engine. The fuel circuit consists of following components.
1. Fuel Tank: This is required to store the fuel.
2. Feed Pump: This generally a piston type pump, which is used to suck the fuel from the tank and pressurize it to a certain, predetermined level. The feed pump is generally mounted on the fuel pump housing and is driven by fuel pump camshaft itself.
3. Hand Primer: In some cases a hand-priming pump is also used to assist the suction of fuel from fuel tank to the feed pump inlet.
4. Fuel Filter: This is used to filter out (trap) any dust, dirt or other foreign particle in the fuel circuit. A filter of suitable capacity and
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filtration efficiency is selected depending upon the engine requirement and application.
5. Fuel Pump: This is used to pressurize and meter the fuel to the required level.
6. High-pressure Pipes: These are used for transfer of highly pressurized fuel from fuel pump to injector.
7. Injector: An injector is generally used to inject the high-pressure fuel into the combustion chamber.
8. Fuel Pump and Injector Leak-off: This is the surplus fuel not injected into the combustion chamber, this is returned to the fuel tank through return lines.
A multi cylinder IC engines make use of a number of individual fuel pumps. Each of the fuel pump is housed separately and is operated by its own camshaft. When such individual fuel pumps are used it has to be ensured that working of all the pumps is synchronized. A delay or lag caused due to malfunctioning of one such individual pump may reduce to the efficiency of the IC engine. Inline A type fuel pumps can be used but these fuel pumps have a limitation on amount of fuel that can be injected per stroke.
This invention seeks to overcome the limitations of the prior art.
Object of this invention is to provide a fuel injection equipment which is simple
and efficient.
Another object of this invention is to provide multiple fuel pumps assembled in a single housing operated by a single camshaft.
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Yet another object of this invention is to provide a fuel pump, which incorporates the advantages of the inline fuel pump as well as an individual fuel pump.
Yet another object of this invention is to provide a fuel injection system wherein each fuel pump can be removed independently and calibrated on test bench.
Summary of the invention:
In accordance with this invention there is provided a fuel injection equipment for an internal combustion engine, said equipment comprising:
(i) a plurality of fuel pumps placed in an aligned manner with respect
to each other, each of said fuel pumps defined by a housing having
a plunger and barrel assembly adapted to pressurize fuel to be
injected, an inlet port for receiving fuel and an outlet port for
delivering pressurized fuel;
(ii) a common shaft adapted to simultaneously drive each of said
plunger of said fuel pumps, said common shaft being connected to
each of said plungers of said fuel pumps;
(iii) a common fuel gallery connected to said inlet ports of said fuel
pump; and
(iv) governing means adapted to selectively control the amount of fuel
delivered to said fuel pumps via said common fuel gallery
connected to said plunger and barrel assemblies of said fuel
pumps.
Typically, the common shaft is a cam shaft.
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Typically, the cam shaft having an arrangement adapted to give
simultaneous predetermined motion to each of said plunger of said fuel
pumps.
Typically, the arrangement provided in the cam shaft spring and roller
tappet.
Typically, the cam shaft is supported in bearing.
Typically, the cam shaft is connected to said plunger of said fuel pumps via
a toothed rack and a toothed sleeve.
Typically, the rack has a linear motion and linear motion of said rack is
converted to rotary motion of said plunger.
Typically, a feed pump is provided which cooperates with said fuel gallery
to supply pressurized fuel is supplied-to said fuel pumps.
Typically, high pressure pipes are fitted to said outlet port to supply fuel to
injector of said internal combustion engine.
Typically, the housing is made of a metal which is at least one chosen from a
group of metals consisting of aluminium, brass and other alloys.
Typically, the bearings are at least one chosen from a group of bearings
consisting of roller bearings and hydrodynamic bearings.
Typically, the camshaft is made of steel material.
Brief description of the accompanying drawings:
The invention will be described in detail with reference to a preferred embodiment. Reference to this embodiment does not limit the scope of the invention, which is limited only by the scope of the claims.
In the drawings:
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Figure 1 illustrates the detailed construction of conventional type fuel pump
used in the IC engines according to the prior;
Figure 2 illustrates the typical fuel circuit uses for flow of fuel in the
conventional diesel IC engine according to the prior art;
Figure 3 illustrates a sectional view of the fuel injection equipment in
accordance with this invention;
Figure 4 illustrates a sectional view of the operative configuration of the fuel
injection equipment in accordance with this invention;
Figure 5 illustrates a partial sectional view of the fuel injection equipment in
accordance with this invention.
Figure 6 illustrates a sectional view of fuel pump as seen along section AA'
in the direction of the arrow 'X' of figure 5
Detailed description of the invention:
The invention will be described in detail with reference to figures 3 to 6 of the accompanying drawings.
Figures 3, 4, 5 and 6 illustrate various section views of the fuel injection equipment in accordance with this invention. The fuel injection equipments has a plurality of fuel pumps (10) housed in a housing (12). The housing (12) is an aluminum cast piece. The housing (12) also housed other components required for operation of the fuel pump unit such as cam shaft, control rack, feed pumps, support bearings and the like components. The fuel pumps are defined by a housing having a plunger (14) and barrel (16) assembly adapted to pressurize fuel to be injected, an inlet port for receiving fuel and an outlet port for delivering pressurized fuel.
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The plurality of fuel pumps (10) are simultaneously driven by a common shaft (18). The common shaft (18) is typically a cam shaft. The cam shaft (18) is connected to and drives each of the plungers (14) of the fuel pumps (10). The cam shaft (18) has an arrangement which give simultaneous predetermined motion to each plunger (14) of the fuel pumps (10). The cam shaft (18) is supported in bearing (20). The bearings (20) are used are roller or hydrodynamic bearings. A common fuel gallery is provided to supply fuel to the plunger (14) and barrel (16) assembly of the fuel pumps (10).
The fuel injection equipment has a governing means which selectively controls the amount of fuel delivered to the fuel pumps via the common fuel gallery connected to the plunger and barrel assemblies of the fuel pumps. The amount of fuel delivered is determined by the load and speed requirement. Though each fuel pump is a separate unit in it self, they are made to operate in a particular sequence matched with the engine firing order.
While considerable emphasis has been placed herein on the various structures and the structural interrelationships of the various components of the preferred embodiment, it will be appreciated that many alterations can be made and that many modifications can be made in the preferred embodiment without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
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We Claim:
1. A fuel injection equipment for an internal combustion engine, said
equipment comprising:
(i) a plurality of fuel pumps placed in an aligned manner with
respect to each other, each of said fuel pumps defined by a housing
having a plunger and barrel assembly adapted to pressurize fuel to be
injected, an inlet port for receiving fuel and an outlet port for
delivering pressurized fuel;
(ii) a common shaft adapted to simultaneously drive each of said
plunger of said fuel pumps, said common shaft being connected to
each of said plungers of said fuel pumps;
(iii) a common fuel gallery connected to each of said inlet ports of
said fuel pump; and
(iv) governing means adapted to selectively control the amount of
fuel delivered to said fuel pumps via said common fuel gallery
connected to said plunger and barrel assemblies of said fuel pumps.
2. A fuel injection equipment as claimed in claim 1, wherein said common shaft is a cam shaft.
3. A fuel injection equipment as claimed in claim 2, wherein said cam shaft has an arrangement adapted to give simultaneous predetermined motion to each of said plunger of said fuel pumps.
4. A fuel injection equipment as claimed in claim 3, wherein said arrangement for cam shaft is a spring and roller tappet.
5. A fuel injection equipment as claimed in claim 2, wherein said cam shaft is supported in bearing.
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6. A fuel injection equipment as claimed in claim 2, wherein said cam shaft is connected to said plunger of said fuel pumps via a toothed rack and a toothed sleeve.
7. A fuel injection equipment as claimed in claim 6, wherein the rack has a linear motion, said linear motion of said rack is converted to rotary motion of said plunger.
8. A fuel injection equipment as claimed in claim 1, wherein a feed pump is provided which cooperates with said fuel gallery to supply pressurized fuel is supplied to said fuel pumps.
9. A fuel injection equipment as claimed in claim 1, wherein high pressure pipes are fitted to said outlet port to supply fuel to injector of said internal combustion engine.
10. A fuel injection equipment as claimed in claim 1, as herein described with reference to the accompanying drawings.
Dated this 9th Day of November 2006.

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ABSTRACT:
A fuel injection equipment for an internal combustion engine is disclosed. The equipment has a plurality of fuel pumps placed in an aligned manner with respect to each other. The fuel pumps are defined by a housing having a plunger and barrel assembly, an inlet port and an outlet port. A common shaft is provided to simultaneously drive the plungers of the fuel pumps via the common shaft. A common fuel gallery is connected to each inlet port and governing means selectively controls the amount of fuel delivered to the fuel pumps.