Field of the Invention
The present invention relates to internal combustion engines,
particularly internal combustion gasoline engine having independent
intake port structures.
Background of the Invention
The conventional internal combustion engine for an automobile includes
each cylinder provided with a fuel injection valve. In such conventional
engines, equal number of fuel injection valves as the number of the
cylinders are mounted to a fuel supply pipe device, which supplies fuel
to the fuel injection valves. The Internal combustion engines with two
intake ports per combustion chamber have been finding utility in recent
years. In such arrangement the air and fuel mixture is allowed to flow
through the intake ports whose cross section is circular or elliptical. A
pent roof is provided at the end of the intake port at an angle such that
it allows the air intake to guide a fresh charge from each intake port
downstream from the cylinder towards the face of the piston and splits
by separation wall in two halves.
The prior art search revealed two citations, first citation relates to a fuel
injection device for an internal combustion engine which includes
intake ports provided in the same cylinder and an intake side valve
train for driving the intake valves while giving a difference in valve
opening property between the intake valves.
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The other citation relates to an injection system for an internal
combustion engine having at least one combustion chamber, the wall of
the combustion chamber has a first inlet port, which is closable by a first
inlet valve, and a second inlet port, which is closable by a second inlet
valve, the injection system includes a first injector for metered injection
of fuel into the area of the first inlet port, a second injector for metered
injection of fuel into the area of the second inlet port, a catalytic
converter unit, and a heating device for rapidly heating the catalytic
converter unit.
To improve the vehicle fuel consumption , there is a need to design an
intake port structure having two intake ports on a combustion chamber
to reduce the flow restriction and boundary layer interface friction.
There is also a requirement to design the cylinder head in such a manner
that it reduces the combustion duration of an engine.
Advantages of the Present Invention
The advantages of the present invention are as follows:
1. Reduction in flow friction losses due to shorter length of the intake
port.
2. Elimination of losses associated with dividing/bifurcation wall eddy
formation and recirculation zones.
3. High intake charge momentum resulting in higher tumble without
need for flow separation edge thereby leading to high flow.
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4. In case of Independent valve actuation, only one valve opens during
part load condition leading to higher throttle opening which results in
lower pumping loss and improvement in vehicle fuel consumption.
Objective of the Invention
The main objective of the present invention is to provide an independent
intake port structure with unidirectional flow of fuel for an internal
combustion gasoline engine that is having independent port structure at
cylinder head intake manifold with dual injectors (i.e. one injector per
port)
Another objective of the present invention is to optimize the air flow
motion from exit of intake manifold to combustion chamber for high
compression ratio (more than 10).
Yet another objective of the present invention is to overcome the
problem of reduction in mass flow rate by providing an intake port
structure that can strengthen tumble motion.
Still another objective of the present invention is to deliver fresh charge
to combustion chamber without any separation wall.
Summary of the Invention
This invention relates to independent intake port structure for internal
combustion gasoline engine wherein the air flow motion is optimized
from exit of intake manifold to combustion chamber for high
compression ratio (more than 10). Compression ratio is a key parameter
which directly affects the thermal efficiency of the engine. The
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phenomenon of knocking in gasoline engine puts a limit to the increase
in compression ratio which affects the low end WOT torque output.
The two independent ports at the entry on intake port through
individual runner of intake manifold inject fresh charge to a pent roof
combustion chamber without dropping the compression ratio. The two
injectors are parallel to each other. The pent roof combustion chamber
allows fresh charge (Air and Fuel) flow without any separation wall. The
intake ports and combustion chamber produces a tumble motion that
becomes stronger due the straight intake ports. The major components
of the invention are intake ports, intake valve, injectors, cylinder head
and combustion chamber.
Brief Description of the Drawings
Fig 1: illustrates schematic representation of the invention.
Fig 2 and Fig 3 illustrates independent ports arrangement for two intake
valve per cylinder gasoline engine.
Detailed Descriotion of the Invention
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As illustrated in Fig 1-3, the present invention relates to an internal
combustion engine having independent intake port structure, wherein
the air flow motion is optimized from exit of intake manifold to
combustion chamber for generating high compression ratio (more than
10).Said intake port are isolated with each other to increase tumble
motion without compromising mass flow rate and are having straight
profile.
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The present invention comprises of at least one intake valve (Fl, F2), at
least one intake port (Gl, G2), a combustion chamber (D), a piston(A), at
least one iniectors(Hl, H2), a cvlinder bore(B) and a cylinder headfC).
According to a preferred embodiment, the present invention comprises
of two intake valves(Fl and F2), two intake ports(Gl and G2), a
combustion chamber(D), a piston(A), two injectors(Hl and H2), a
cylinder bore(B) and a cylinder head(C).
During intake stroke as piston (A) moves in the downward direction ,
both the intake valves(Fl and F2) associated with piston(A) begin to
open. Fresh charge i.e. a mixture of fuel and air enters into the
combustion chamber (D) without dropping the compression ratio. The
mixing of air and fuel mixture is done in the combustion chamber (D) by
turbulence (tumbling motion) generated because of high kinetic energy
produced by independent intake port structure (Gl and G2). The pent
roof combustion chamber(D) is at an angle that ranges between 0^5
degrees and guides the fresh charge flow without any separation wall
from each intake port(Gl and G2) at downstream from the cylinder(B
and C) towards the face of the piston(A). Furthermore the area of the
port is reduce to increase flow velocity to a maximum of lOOm/s.
Fuel(El and E2) is sprayed in the air stream through each of the intake
port structure by two injectors(Hl and H2) that are parallel to each
other.
In an another embodiment of the present invention, small cross-section
of the intake port structures (Gl cind G2) allows high kinetic energy flow
without any loss. The two independent ports at the entry of intake port
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through individual runner of intake manifold , inject fresh charge to a
pent roof combustion chamber(D) without dropping the compression
ratio. The intake ports(Gl and G2) and combustion chamber(D)
produces a tumble motion that becomes stronger due the straight profile
of intake ports. The tumble motion enhances flame propagation velocity,
combustion stability and the thermal efficiency.
In an another embodiment both the valves work independently , only
one valve opens during part load condition leading to high throttle
opening and resulting in lower pump loss. One injector per port
increases the compression ratio leading to improvement in vehicle fuel
consumption.
Yet in another embodiment of the present invention, the cylinder
head(C) is designed in such a way that reduces the combustion duration
and intake port is designed in such a way to create tumble motion i.e.
enhancing the turbulence of incoming air fuel mixture in the combustion
chamber.
The invention is described herein is illustrative only and should not be
construed to limit the scope of the present invention in any manner.
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We Claim:
1. An internal combustion engine having independent port
structures, said engine comprises:
- at least one intake valve(Fl,F2);
- at least one intake port(Gl, G2);
- at least one injector(Hl,H2); and
- a combustion chamber(D),
characterized in that said intake port are isolated with each other to
increase tumble motion without compromising mass flow rate and
have straight profile.
2. An interrml combustion engine as claimed in Claim 1 , wherein
there is one said injector for one said intake port.
3. An internal combustion engine as claimed in any of the preceding
claims, wherein said intake port and said intake valves are preferably
two in number.
4. An internal combustion engine as claimed in any preceding claims,
wherein said intake port have small cross sectional area for high
kinetic energy flow without any loss.