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FIELD OF INVENTION
This invention relates to a single structure rail assembly for bi-fuel vehicle. The
rail assembly is mounted on intake manifold for direct feeding of CNG into
intake manifold through injectors.
BACKGROUND/PRIOR ART OF THE INVENTION
Currently available bi-fuel vehicles are provided with CNG injectors mounted
separately and gasoline injectors mounted directly on intake manifold.
Referring to fig. l,the arrangement comprises of CNG rail (a) mounted on
intake manifold (e). In this, CNG gas flows from CNG rail to combustion engine
chamber through a plurality of CNG injectors (b), hoses (c), and pipes (d),
which are connected with the help of a number of clamps (fj.
The aforesaid arrangement is suitable for a small car like Alto. However, the
drawbacks associated with the same are that, it has multiple number of parts
resulting in complicated layout with heavy weight and high cost. Further, it
requires five mounting points for CNG and gasoline rail mounting.
Therefore, another arrangement is also known in the art, which is better than
the above and discussed hereinbelow:-
Referring to fig. 2, wherein the arrangement is suitable for a medium sized car
like Omni. In this, both CNG injectors (p) and gasoline injectors (q) are directly
mounted on the intake manifold. In this arrangement, CNG rail (r) is mounted
on intake manifold (s). CNG gas flows from the rail to combustion engine
through CNG injectors mounted directly on intake manifold(s) like gasoline
injectors.
In the above provision, CNG fuel hoses from injectors to intake manifold are
deleted, thereby making it compact and easy to assemble. This is because CNG
injectors (P) are mounted directly on intake manifold (s) like gasoline injectors.
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Further, this arrangement also reduces overall vehicle weight comparatively.
However, the drawback associated with the above is that, it requires four
mounting points (C and G) for CNG rail and gasoline rail mounting.
Further drawbacks common to both aforesaid prior arts are given hercinbelow:
- Time consuming assembly due to presence of many components.
- Heavy CNG rail and injector assembly because of many parts and also
due to placement of CNG injectors between rail and sheet metal bracket.
- Less dynamic response of the vehicle due to long distance between CNG
injector and combustion chamber.
- High cost because both rails are separate not integrated, wherein
gasoline rail is made of sheet metal/casting and CNG rail is made of
sheet metal.
Now, reference may be made to the following prior arts:-
EP 1598546B1:- The invention relates to a duel-fuel system for a combustion
engine comprising at least one first injector for feeding a first fuel to the engine
and at least one second injector for feeding a second fuel to the engine, said
first and second injectors being separate and said first and second fuels being
different from each other. Said system further comprises a fuel rail component
defining a first fuel path for supplying said first fuel to said first injector and a
second fuel path for supplying said second fuel to said second injector, said
first and second fuel paths being separate. The invention also relates to a fuel
rail component.
It does not give any location for fuel rail mounting.
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JP 2005155570A:- A gasoline injector 26 to inject gasoline and a hydrogen
injector 27 to inject hydrogen are mounted on an intake passage 25, and the
mounting positions of the injectors 26 and 27 are set to be predetermined
positions so that gasoline spray injection from the gasoline injector 26 and
hydrogen jet injected from the hydrogen injector 27 collide with each other.
It only shows the location for different injector.
CN 201068831Y:- The utility model relates to an engine dual-fuel intake
manifold which comprises an intake manifold airway and an intake manifold
flange, the nozzle mounting step of a first kind of fuel is integrally cast and
arranged at the position where is just above the intake manifold airway and
near the intake manifold flange, the nozzle common-rail mounting hole of the
first kind of fuel and the nozzle mounting hole of the first kind of fuel are
processed and arranged on the nozzle mounting step of the first kind of fuel. In
addition, the nozzle mounting step of a second kind of fuel is integrally cast
and arranged at the position where is below the intake manifold airway and
near the intake manifold flange, the nozzle common-rail mounting hole of the
second kind of fuel and the nozzle mounting hole of the second kind of fuel are
processed and arranged on the nozzle mounting step of the second kind of fuel.
The utility mode simply achieves the assembly of the nozzle common-rail of two
different kinds of fuel, and the design and the arrangement of the nozzle
mounting hole position of the two different kinds of fuel on one intake
manifold, achieving the injection of the two kinds of fuel; the structure is
simple, and the processing is convenient. The utility model can better meet the
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requirements of the common-rail assembly of the nozzles of the two different
kinds of fuel and the arrangement of different injection angles.
It only shows the location for different injector.
Hence, the present invention is introduced to overcome the above
disadvantages.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide single structure rail
assembly for bi-fuel vehicle to obviate drawbacks associated with the known
arts.
Another object of the present invention is to provide single structure rail
assembly for bi-fuel vehicle which is simple in construction and cost effective.
Further object of the present invention is to provide single structure rail
assembly for bi-fuel vehicle which is efficient and reliable.
SUMMARY OF INVENTION
This invention provides a single structure rail assembly for bi-fuel vehicle
comprising of a CNG rail and gasoline rail connected to each other together
with a plurality of extended members provided with said CNG and gasoline rail
for mounting on intake manifold, wherein said rail assembly is mounted at
atleast three points on the intake manifold.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from
the ensuing description when read in conjunction with the accompanying
drawings and wherein:
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Figure 1 shows: conventional rail mounting assembly for bi-fuel vehicle.
Figure 2 shows: another known rail mounting assembly for bi-fuel vehicle.
Figure 3 shows: intake manifold with mounting points for single structure rail
assembly according to the present invention.
Figure 4 shows: intake manifold mounted with novel single structure rail
assembly of the present invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS
The present invention is directed to single structure rail assembly for bi-fuel
vehicle. Now, reference may be made to fig. 3, wherein the arrangement
comprises of atleast three bosses (1) for mounting of integrated rail assembly
(fig. 4) of the present invention. Further, there is provision of a plurality of CNG
injectors (2) mounted on intake manifold (I) so as to directly inject CNG into
said intake manifold. Similarly, a number of gasoline injectors (3) are also
mounted on the intake manifold to directly inject gasoline into the intake
manifold. The above provision eliminates hose between the injcctor(s) and
intake manifold.
Now, referring to fig. 4, in which the integrated rail assembly comprising of a
CNG rail (4) and a gasoline rail (5) connected to each other by means of a
connecting member (6).
Further, a plurality of extension members (7) are connected on both sides of
the CNG and gasoline rails, which act as bracket.
The above discussed rails, connecting means and extension members are
integrally provided constituting a single piece. Thus, a common rail is provided
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for both CNG and gasoline injectors. It is made of material such as sheet metal,
Aluminium, cast iron without restricting scope of the invention to the same.
Thus, the materials apparent to the person skilled in the art are understood to
be within the scope of the invention.
The rail assembly is preferably made of Aluminium (Al) for light weight. Said
rail assembly can be manufactured by casting/forging/any method suitable for
making the rail assembly.
Due to the provision of a single structure of mounting rails, minimum gap
between the rails can be maintained to be mounted on atleast three mounting
points with the help of brackets.
Due to the minimum gap between the rails, the mounting rail assembly is
comparatively nearer to the combustion chamber.
Again, it does not require to have bracket underneath the rail i.e. between the
injectors and rail, thereby reducing the weight.
Further, number of mountings is also reduced in the instant invention as
pcompared to the prior art i.e. it requires three mounting to serve the same
purpose, whereas as already indicated the conventional arrangements require
four/five mountings.
However, the number of mountings can vary according to the requirement. In
any case, it is less in comparison to the prior art. Thus, it is more efficient.
At the time of Engine dynamic condition both type of injectors should perform
their primary function that is to inject fuel at prescribed limit without any
leakage. These mountings also provide the force which clamp together intake
manifold, CNG injector & Gasoline injectors. The other important factor is the
direction of the injectors, the direction in which the mounting is being done.
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Thus, in the exemplary embodiment of the present invention, two mounting
points are provided away from the gasoline rail and another one mounting
point is positioned at the other end of the manifold i.e. away from the CNG rail
(4).
Further, the gasoline and CNG injectors are disposed at an angle with respect
to the rail assembly thereabove. Again, the centre to centre distance between
the CNG and gasoline injectors is maintained at a value for required layout and
performance of injectors, wherein the gasoline injectors are provided in
proximity to the combustion chamber.
With the help of the above, fuel can be directly fed into the intake manifold
from the CNG injectors mounted thereon. This eliminates provision of hose
from CNG injectors to intake manifold. Thus, CNG gas flows from CNG rail to
engine combustion chamber through the CNG injectors mounted directly on
said intake manifold like gasoline injectors. This provision makes it compact
and easy to assemble online.
Advantageous Features
- Robust
- Cost effective
- Efficient
- Reliable
- Single structure
- Common rail for both CNG and gasoline
- Less no. of mounting and less material as compared to prior art.
- Compact and ease in assembly.
It is to be noted that the present invention is susceptible to modifications,
adaptations and changes by those skilled in the art. Such variant embodiments
employing the concepts and features of this invention are intended to be within
the scope of the present invention, which is further set forth under the
following claims:-

CLAIM:
1. A single structure rail assembly for bi-fuel vehicle comprising of a CNG
rail and gasoline rail connected to each other together with a plurality of
extended members provided with said CNG and gasoline rail for
mounting on intake manifold, wherein said rail assembly is mounted at
atleast three points on the intake manifold.
2. A single structure rail assembly as claimed in claim 1, wherein said CNG
rail and gasoline rail are connected to each other by means of a
connecting member.
3. A single structure rail assembly as claimed in claim 1 or 2, wherein the
extended members are connected to said CNG and gasoline rail to act as
bracket.
4. A single structure rail assembly as claimed in any of the preceding
claims, wherein said brackets are mounted on atleast three mounting
points provided on said intake manifold.
5. A single structure rail assembly as claimed in any of the preceding
claims, wherein said CNG and gasoline rail in conjunction with
connecting means and extended members are integrally provided
constituting a single structure.
6. A single structure rail assembly as claimed in any of the preceding
claims, wherein the gasoline and CNG injectors are disposed at an angle
with respect to the rail assembly thereabove and the centre to centre
distance between the CNG and gasoline injectors is maintained at a value
for required layout and performance of injectors, in which the gasoline
injectors are provided in proximity to the combustion chamber.
7. A single structure rail assembly as claimed in any of the preceding
claims, wherein two mounting points are provided away from the
gasoline rail and another one mounting point is positioned at the other
end of the manifold i.e. away from the CNG rail.
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8. A single structure rail assembly as claimed in any of the preceding
claims, wherein the rail assembly can be manufactured by
forging/casting/any suitable method such as herein described.
9. A single structure rail assembly as claimed in claim 8, wherein the rail
assembly is made of material such as Alumninium, Cast iron, sheet
metal.
10. A single structure rail assembly as claimed in any of the preceding
claims, wherein the CNG and gasoline rail are provided maintaining
minimum required gap therebetween, thereby positioning the rail
assembly in proximity to the combustion chamber.
11. A single structure rail assembly as claimed in any of the preceding
claims, which eliminates provision of hose from injectors to intake
manifold by directly feeding fuel into the intake manifold from the CNG
rail through CNG injectors.
12. A single structure rail assembly as claimed in any of the preceding
claims, is associated with the advantageous features such as herein
described.