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FIELD OF INVENTION
This invention relates to an improved fuel delivery pipe for fuel injection system
of vehicle. The delivery pipe is provided with four leg mountings and antirotation
means for optimum performance of fuel injection system.
PRIOR ART
Fuel injection system of vehicle comprising of a delivery pipe (rail) for supply of
fuel from tank into the combustion chamber of engine through a plurality of
hoses and injectors under high pressure.
During operation of vehicle, force is exerted on the delivery pipe due to high
pressure inside said injectors. This may lead to deflection of the delivery pipe in
the middle.
Again, the injector is required to be in place by controlling its rotation for
efficient functioning of the fuel injection system.
Now, reference may be made to the following prior arts:-
EP 1529955:- This invention discloses a clamping arrangement for securing a
plurality of fuel injectors to an engine assembly, preferably onto a cylinder
head thereof. The clamp comprises a longitudinally extending beam having at
each end thereof an injector clamping member arranged in use to impart a
clamping force onto a clamping portion associated with an injector. The beam
has defined therethrough and in between the clamping members at least one
fixing hole adapted to receive an associated mechanical fixing for imparting the
clamping force and the or each fixing hole and the clamping members are
substantially in-line with each other. Each injector clamping member
comprises a closed flange that in use completely surrounds a portion of its
associated fuel injector and each closed flange is provided with at least
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one anti-rotation means that is arranged in use to engage with an anti-rotation
means of the fuel injector.
It is provided with a longitudinally extending beam to stop the injector rotation
with no provision for avoiding deflection of the rail.
WO 2009144069A:- It relates to the hold-down member according to the
invention for a fuel injection device characterized by a design, which still
enables a fuel injection valve to be held down very effectively. The fuel injection
device comprises at least one fuel injection valve, a receiving bore for the fuel
injection valve, and a connector of a fuel distributor line, wherein the holddown
member is clamped between a shoulder of the fuel injection valve and an
end surface of the connector. The hold-down member has a partially annular
base element, from which an axially flexible hold-down bracket extends at a
bend, said bracket having at least two webs, two slanted sections, and two
contact sections. The fuel injection valve is particularly suited for use in fuel
injection systems of mixture-compressing, spark-ignited internal combustion
engines.
It comprises of a hold down member to hold the injector in place without any
provision for anti rotation of the injector. Again, the member constitutes an
additional component.
WO 2006137298A1:- It relates to a positioning structure of a fuel injector
enabling the secure holding of the fuel injector, the use of a compact clip, and
the easy molding of the clip. The positioning structure comprises holding
tongue pieces and forming a projected part on the center peripheral surface of
the fuel injector and holding the peripheral surface of a branch pipe, a stopper
means brought into contact with a fuel feed pipe to stop the rotation of the
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branch pipe relative to its axis, and the clip having a recessed part for fitting
the projected part of the fuel injector thereto in the axial direction of the branch
pipe. The holding tongue pieces and of the clip are held on the peripheral
surface of the branch pipe, the stopper means is engaged with the fuel feed
pipe, and the projected part of the fuel injector is fitted to the recessed part of
the clip to position the fuel injector relative to the axis of the branch pipe in the
rotating direction.
This Patent involves a very complicated mechanism to control the
rotation/position of fuel injector.
US 6276339B1:- This relates to a spring clip assembly for connecting a fuel
injector to a fuel rail in an internal combustion engine comprising a
substantially circular ring having a circumferential outer surface, to which are
attached a first and a second plurality of elongate fingers. The first plurality of
elongate fingers extends in a first direction parallel to the axis of the ring and
includes connecting means for attaching the ring to a fuel injector. The second
plurality of elongate fingers extends in a second, opposite axial direction and
includes connecting means for attaching the ring to the fuel rail. The spring
clip assembly further comprises spring means held proximate a surface of the
ring by either the first plurality or the second plurality of elongate fingers. The
spring means provides a compressive load between the fuel injector and the
fuel rail. A fuel rail-injector assembly comprises a fuel rail, a plurality of fuel
injectors, and a corresponding plurality of the just-described spring clip
assemblies for connecting the injectors to the rail.
EP 1046810A2:- It discloses a mounting arrangement with a fuel rail having a
plurality of fuel injector cups, a plurality of fuel injectors, and a clip. The fuel
injector cups include a cylindrical tube defining a longitudinal axis, a fuel rail
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mounting section disposed at a first end of the tube, and a lip at a second end
of the tube. Each of the fuel injectors corresponding to one of the plurality of
fuel injector cups. The fuel injectors have a housing with a retention groove.
The clip engages both the lip of the fuel injector cup and the retention groove
in the housing of the fuel injector to secure the fuel injector to the fuel injector
cup and allow the fuel injector to reciprocate along the longitudinal axis.
It requires additional metallic clip for anti rotation of said injector.
Again, reference may be made to fig. 1 indicating delivery pipe with three legs
for mounting on intake manifold. However, it does not ensure injector
installation height.
Referring to US 6405713, which is provided with two legs for mounting.
However, length of legs does not ensure injector installation height. Further,
direction of mounting is not parallel to the injector axis to ensure alignment of
injector.
Again, referring to another prior art as shown in fig. 2, in which all three legs
are used for mounting of delivery pipe. This also does not ensure the injector
installation height.
Hence, the present invention is proposed to address the aforesaid drawbacks.
Further, the invention prevents deflection of delivery pipe and controls rotation
of injector.
OBJECTS OF THE INVNETION
The primary object of the present invention is to provide an improved fuel
delivery pipe for fuel injection system of vehicle which overcomes disadvantages
associated with the prior arts.
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Another object of the present invention is to provide an improved fuel delivery
pipe for fuel injection system of vehicle which is simple in construction.
Further object of the present invention is to provide an improved fuel delivery
pipe for fuel injection system of vehicle which is efficient and reliable.
SUMMARY OF THE INVENTION
According to this invention, there is provided an improved fuel delivery pipe for
fuel injection system of vehicle comprising of a fuel delivery pipe integrally
provided with atleast four legs for mounting on intake manifold and anti
rotation member to control rotation of injector supporting the rail, wherein the
injector is mounted on said 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:
Fig. 1 shows: conventional delivery pipe.
Fig. 2 shows: delivery pipe known in the art.
Fig. 3 shows: novel fuel delivery pipe according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS
The present invention discloses an improved fuel delivery pipe for fuel injection
system of vehicle. As it is known, fuel delivery pipe is an integral part of fuel
system of vehicle, which is assembled on the engine.
Now, reference may be made to fig. 3, wherein the delivery pipe (1) is provided
on a plurality of injectors (2), which are mounted on intake manifold (3),
purpose of which is suction and passage of air into combustion chamber.
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Primarily the delivery pipe serves as a channel of fuel supply from the
underbody fuel pipe to a plurality of injectors, wherein the fuel pipe carries fuel
from fuel tank to the engine room. Said injectors further spray the fuel into
intake ports for supplying fuel to combustion chamber of the engine. Thus, a
number of injectors and hoses are assembled to the rail while supplying fuel
under high pressure.
The pressure in the delivery pipe is normally around 4.0 bar. However,
opening/closing of the injector leads to pulsations in fuel flow along the
complete circuit.
Maximum amplitude is found in the delivery pipe i.e. rail. Hence, the fuel
deliver pipe is required to act as a surge tank as well as a pulsation damper.
Further, to avoid deflection of the rail due to exertion of force during vehicle
movement, the delivery pipe (rail) is integrally provided with atleast four legs.
Said legs are directly mounted on the intake manifold. Thus, the rail is
provided with a secondary mounting on said intake manifold. Again, the
provision of legs ensures the injector installation height during high engine
vibrations and also ensures normal functioning of the fuel injection system for
the entire life of vehicle. Fuel injector installation height is perpendicular
distance between two injector mounting surfaces.
Out of four legs of delivery pipe, outer two legs (5) are used for mounting of
delivery pipe on the intake manifold. Remaining two inner legs (4) of said
delivery pipe are used to hold the injectors between delivery pipe and intake
manifold so as to ensure installation height of all three injectors. This is
because the height is required to be controlled to avoid the fuel
leakage/seepage. Thus, the length of inner two legs is determined relying on
the requirement of injector installation height.
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Further, there is a controlled tolerance over the length of inner legs to control
installation height of three injectors.
Again, alignment of axis of injector with axis of delivery pipe and intake
manifold is very important in order to avoid fuel leakage due to inclination of
injector. Hence, to take care of injector alignment, inner legs mounting is
carried out along the length of said injector.
The delivery pipe can be of any material such as Aluminium, sheet metal,
plastic. However, plastic pipe is preferred over Aluminium and sheet metal pipe
because it is light in weight and corrosion free.
Further, manufacturing of the metallic delivery pipe involves a long procedure,
whereas manufacturing process of the plastic delivery pipe is simple.
Again, the injectors are required to have desired orientation so as to ensure
correct fuel spray pattern for optimum atomization of fuel droplets in the
combustion chamber of engine. To achieve the same, the rail is integrally
provided with an anti rotation member (6) as shown in the figure 1.
The anti rotation member (6) comprising of a projected member provided away
from the rail. The anti rotation member restricts rotation of said injector by
striking against coupler (7) provided with said injector. The coupler acts as an
inlet for supply of charge to operate the injector.
The anti rotation member can be made of material such as Aluminium, sheet
metal, plastic. However, plastic is preferred over other materials because of its
light weight. The light weight of member leads to reduction in cost and
improvement in fuel efficiency.
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Further, the above provision does not require an additional part (clip) unlike
the prior art to lock the injector rotation. Thus, less number of parts in
assembly leads to ease in assembly.
The delivery pipe of the present invention can be manufactured by method
such as injection moulding. However, the material and method are given as
example. Any other materials and methods readily apparent to person skilled
in the art are understood to be within scope of the invention.
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:

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WE CLAIM;
1. An improved fuel delivery pipe for fuel injection system of vehicle
comprising of a fuel delivery pipe integrally provided with atleast four
legs for mounting on intake manifold and anti rotation member to control
rotation of injector supporting the rail, wherein the injector is mounted
on said intake manifold.
2. An improved fuel delivery pipe as claimed in claim 1, wherein the outer
two legs are provided for mounting of rail on the intake manifold and the
inner two legs are provided to ensure injector installation height during
high engine vibrations and normal functioning of the fuel injection
system.
3. An improved fuel delivery pipe as claimed in claim 1 or 2, wherein the
inner two legs further prevent deflection of said rail during vehicle
movement and are disposed in parallel with the injector to avoid fuel
leakage.
4. An improved fuel delivery pipe as claimed in any of the preceding claims,
wherein length of the inner two legs is determined according to the
requirement of injector installation height together with controlled
tolerance over the length of inner legs to control installation height of
injectors.
5. An improved fuel delivery pipe as claimed in any of the preceding claims,
wherein said anti rotation member comprising of a projected member
provided away from said rail.
6. An improved fuel delivery pipe as claimed in claim 5, wherein said anti
rotation member is provided for each injector on the intake manifold.
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7. An improved fuel delivery pipe as claimed in any of the preceding claims,
wherein the anti rotation member is preferably made of plastic, which
results in reduction of weight and improvement is fuel efficiency.
8. An improved fuel delivery pipe as claimed in any of the preceding claims,
wherein the anti rotation member is provided for the desired orientation
of injectors so as to ensure the correct fuel spray pattern for optimum
atomization of fuel droplets in combustion chamber.
9. An improved fuel delivery pipe for fuel injection system of vehicle
substantially as herein described with reference to the accompanying
drawings.