[001] The present disclosure generally relates to the field of exhaust systems of internal
combustion engines. More particularly, the disclosure is directed towards a safety unit of
exhaust system of internal combustion engines.
5
BACKGROUND OF DISCLOSURE
[002] An exhaust system is an essential part of an internal combustion engine system.
The exhaust systems are provided to safely route exhaust gases from the engine to the
environment. The exhaust system is typically connected to an exhaust manifold, which
10 collects exhaust gases from the exhaust ports of the engine cylinders. A certain exhaust
gas pressure is required to overcome the hydraulic resistance of the exhaust system in
order to discharge the gases into the atmosphere. Due to high buildup of temperature
causes thermal expansion which could be fatal for the system. It has also seen that such
thermal expansion causes jamming issues between the mechanical interaction of the
15 components in the exhaust systems.
[003] Further, in order to control the direction of flow in exhaust systems, between
retrofit and main line system a lot of bend, obstruction and other similar things are
included which increases the back pressure in the system. Increased back pressure in
20 exhaust line may affect the performance of the engine, reduce engine efficiency and could
hamper the life of engine. Also, controlling the direction of flow in retrofit exhaust
systems produces high pressure drop.
[004] Various solutions were devised to cure the above-mentioned problems. One such
25 solution was providing a provision of one control valve at main and bypass lines each
along with two separate actuators with separate and independent control and delay logic.
Due to separate systems for operation of main and bypass lines such solution becomes
highly complex. Such complexity increases risk of failure of the system due to large
number of dynamic and digital components.
30
3
[005] The existing systems were also not able to mitigate the issues caused due to
uncertain flow dynamic nature of exhaust gases.
[006] Accordingly, there is a need in the art to provide a safety unit of exhaust system
5 of internal combustion engines which can overcome one or more limitations stated above
or any other limitations associated with the prior art.
SUMMARY
[007] One or more drawbacks of conventional safety units as described in the prior
10 art are overcome and additional advantages are provided as through a safety unit as
claimed in the present disclosure. Additional features and advantages are realized
through the technicalities of the present disclosure. Other embodiments and aspects of
the disclosure are described in detail herein and are considered to be a part of the
claimed disclosure.
15
[008] The present disclosure provides a safety unit in accordance with an exemplary
embodiment of the disclosure. The safety unit comprises a main chamber, an inlet port
attached with the exhaust system of the internal combustion engine to receive exhaust
gases from an inlet line, an outlet port connected with an outlet line and being configured
20 to expel exhaust gases from the engine, a bypass port; and a flap assembly accommodated
in the main chamber and configured to selectively regulate the direction of flow of exhaust
gases through either of the outlet port or the bypass port.
[009] In an embodiment of the present disclosure, the flap assembly comprises a flap
25 configured to move between a first position and a second position to selectively allow
passage of exhaust gases through either of the outlet port or the bypass port.
[010] In an embodiment of the present disclosure, in the first position, the flap is
configured to close the bypass port so as to allow flow of the exhaust gases from the inlet
4
port to the outlet port and in the second position, the flap is configured to close the outlet
port so as to allow flow of the exhaust gases from the inlet port to the bypass port.
[011] In an embodiment of the present disclosure, the flap is actuable by an actuator.
5
[012] In an embodiment of the present disclosure, the flap comprises a fixed end and a
free end, the fixed end being configured with a flap rod mounted hingedly, such that the
free end movable swingably about the fixed end of the flap.
10 [013] In an embodiment of the present disclosure, the flap is wedge shape flap having a
triangular cross section whereby free end of the flap is thicker than the fixed end.
[014] In an embodiment of the present disclosure, the flap assembly selectively
comprises a second flap attached with the flap rod and configured to actuate movement
15 of the first flap between the first and the second positions.
[015] In an embodiment of the present disclosure, a torsion spring attached with the flap.
[016] In an embodiment of the present disclosure, the main chamber comprises a cutout
20 provided at the wall of the main chamber to connect a pressure relief valve chamber.
[017] The foregoing summary is illustrative only and is not intended to be in any way
limiting. In addition to the illustrative aspects, embodiments, and features described
above, further aspects, embodiments, and features will become apparent with reference
25 to the drawings and the following detailed description.
BRIEF DESCRIPTION OF FIGURES
[018] The novel features and characteristics of the disclosure are set forth in the
description. The disclosure itself, however, as well as a preferred mode of use, further
30 objectives and advantages thereof, will best be understood by reference to the following
5
description of an illustrative embodiment when read in conjunction with the
accompanying drawings. One or more embodiments are now described, by way of
example only, with reference to the accompanying drawings wherein like reference
numerals represent like elements and in which:
5 FIG. 1 illustrates an exploded view of a safety unit in accordance with n embodiment of
the present disclosure.
FIG. 2 illustrates a perspective view of the safety unit in accordance with an embodiment
of the present disclosure.
FIG. 3 illustrates a perspective view of flap assembly of the safety unit in accordance
10 with an embodiment of the present disclosure.
FIG. 4 illustrates a perspective view of flap assembly of the safety unit in accordance
with another embodiment of the present disclosure.
FIG. 5 illustrates a perspective view of the safety unit disclosing configuration of seats
in accordance with an embodiment of the present disclosure.
15 FIG. 6 illustrates a perspective view of the safety unit disclosing configuration of outlet
section in accordance with an embodiment of the present disclosure.
FIG. 7 illustrates a schematic view of the safety unit disclosing configuration of outlet
section in accordance with another embodiment of the present disclosure.
FIG. 8 illustrates a schematic view of the safety unit disclosing configuration of bypass
20 section in accordance with an embodiment of the present disclosure.
[019] Skilled artisans will appreciate that elements in the drawings are illustrated for
simplicity and have not necessarily been drawn to scale. For example, the dimensions of
some of the elements in the drawings may be exaggerated relative to other elements to
help to improve understanding of embodiments of the present disclosure.
25
DETAILED DESCRIPTION
6
[020] While the disclosure is susceptible to various modifications and alternative forms,
specific embodiment thereof has been shown by way of example in the figures and will
be described in detail below. It should be understood, however that it is not intended to
limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure
5 is to cover all modifications, equivalents, and alternative falling within the spirit and the
scope of the disclosure as defined by the appended claims.
[021] Before describing in detail embodiments, it may be observed that the novelty
and inventive step that are in accordance with the present disclosure resides in a safety
10 unit for an exhaust system. It is to be noted that a person skilled in the art can be
motivated from the present disclosure and modify the various constructions of the
safety unit. However, such modification should be construed within the scope and
spirit of the disclosure. Accordingly, the drawings are showing only those specific
details that are pertinent to understanding the embodiments of the present disclosure so
15 as not to obscure the disclosure with details that will be readily apparent to those of
ordinary skill in the art having benefit of the description herein.
[022] The terms “comprises”, “comprising”, or any other variations thereof, are
intended to cover a non-exclusive inclusion, such that a setup, device that comprises a list
20 of components does not include only those components but may include other
components not expressly listed or inherent to such setup or device. In other words, one
or more elements in a system or apparatus proceeded by “comprises… a” does not,
without more constraints, preclude the existence of other elements or additional elements
in the system or apparatus.
25
[023] The present disclosure generally relates to the field of exhaust systems of internal
combustion engines. More particularly, the disclosure directed towards a safety unit of
exhaust systems of internal combustion engines.
7
[024] Reference will now be made to the exemplary embodiments of the disclosure, as
illustrated in the accompanying drawings. Wherever possible same numerals will be used
to refer to the same or like parts.
5 [025] Fig. 1 illustrates a safety unit (100) for an exhaust system of an internal
combustion engine in accordance with an exemplary embodiment of the present
disclosure. The safety unit (100) comprises a main chamber (10), an inlet port (13), an
outlet port (14), and a bypass port (15). The main chamber (10) provides a housing for all
components of the safety unit (100). Also, the main chamber (10) provides space for
10 direction control operations of exhaust gases. In an embodiment of the present disclosure,
the inlet port (13) is attached with the exhaust system of the internal combustion engine
to receive exhaust gases from an inlet line (131)
[026] As shown in figures 1 and 3, the safety unit (100) comprises a flap assembly (11)
15 accommodated in the main chamber (10). The flap assembly (11) comprises at least one
flap (110). The flap (110) is configured to move between a first position and a second
position to selectively allow passage of exhaust gases through either of the outlet port
(14) or the bypass port (15) to control the direction of exhaust gases. In an embodiment
of the present disclosure, the outlet port (14) is connected with an outlet line (141) to
20 expel exhaust gases from the engine. In another embodiment of the present disclosure,
the bypass port (15) is connected with a bypass line (141) to expel exhaust gases from the
engine during high pressure build up at the exhaust system.
[027] In an embodiment of the present disclosure, in the first position, the flap (110) is
25 configured to close the bypass port (15) so as to allow flow of the exhaust gases from the
inlet port (13) to the outlet port (14) and at the second position, the flap (110) is configured
to close the outlet port (14) so as to allow flow of the exhaust gases from the inlet port
(13) to the bypass port (15).
30
[028] In an embodiment of the present disclosure, the flap assembly comprises a flap
rod (112) and a hinge (not shown in figures). The at least one flap (110) is removably
8
attached with the flap rod (112) with help of a fastening means. The flap rod (112) is
pivotally mounted on the hinge and coupled with an actuator (12) via fastening means.
The flap rod (112) transfers the rotational moment from the actuator (12) to the flap (110).
The actuator (12) is configured to control the direction of flow between the outlet port
5 (14) and the bypass port (15) by selectively opening/closing the outlet or the bypass port
with the flap (110). In another embodiment of the present disclosure, the actuator (12) is
operated with the help of electrical or mechanical devices such as electric motor,
pneumatic cylinders etc.
10 [029] In an embodiment of the present disclosure, the hinge comprises a plurality of
cylindrical pieces with a through hole to provide a pivot point for the flap rod (112). A
clearance is provided between the flap rod (112) and the hinge. The clearance is
configured to accommodate thermal expansion under high temperature conditions and
facilitate smooth movement of the flap rod (112). In another embodiment of the present
15 disclosure, the fastening means can be a coupling means, plurality of screws, sealing
means or one or more of fasteners and the like.
[030] In an embodiment, as shown in figure 3, the flap (110) comprises a fixed end (114)
and a free end (113). The fixed end (114) being configured with the flap rod (112)
20 mounted hingedly, such that the free end (113) movable swingably about the fixed end of
the flap (110). In another embodiment, the flap (110) has a wedge like configuration. The
flap is having a triangular cross section whereby free end (117) of the flap (110) has a
predetermined thickness which is greater than the thickness of the fixed end (116). Due
to such shape, a flow from inlet impacts the flap (110) at an angle other than being
25 perpendicular, hence reducing the force acting on it thereby the amount of torque required
to move the flap (110) is also reduced. In an embodiment of the present disclosure, the
flap rotation angle is in the range of 50-110
○
. In yet an embodiment of the present
disclosure, the flap (110) is a rectangular shape flap.
30 [031] In an embodiment of the present disclosure, as shown in figure 4, the flap
assembly (11) comprises two flaps (110, 111) adapted to be attached with the flap rod
9
(112) and moving independently between the first and the second positions. A second flap
(111) is configured with the first flap (110) and is coupled with the actuator (12) so as
move the first flap from the first position to the second position. The second flap (111) is
configured as a failsafe mechanism in case the actuator (12) fails to move the first flap
5 (110) to the second position. The second flap (111) by the impact of flow from inlet of
exhaust gases, creates a momentum on first flap and thereby moves the first flap (110) to
the second position exposing the bypass port (15) to safely route exhaust gases from the
engine.
10 [032] In an embodiment of the present disclosure, a torsion spring (not shown) as an
energy storage medium is attached with the flap (100) to store the energy generated due
to movement of the flap (110) from the first position to the second position. The energy
stored in the torsion spring can be used to move the flap (110) from the second position
to first position.
15
[033] In an embodiment of the present disclosure, as shown in figure 5, the safety unit
(100) comprises a plurality of seats (16). The seats (16) are provided at the outlet port
(14) and the bypass port (15) of the main chamber (10). The seats (16) are configured to
a contact area for the flap (110) for negligible leakage closure. In another embodiment,
20 the seats are a ringed shaped body and provides a flat surface for the flap (110) to
completely shut of the desired ports to prevent leakage. In yet another embodiment of the
present disclosure, the seats (16) are made of separate parts which are to be joined at the
main chamber (10) to compensate the defects caused in the manufacturing of chamber
when seats are jointed and ensure mitigation of internal leakage.
25
[034] In an embodiment of the present disclosure, as shown in figure 6, a hollow section
(18) is adapted with the outlet port (14) of the safety unit (100). In an embodiment, the
hollow section (18) can be conical, cylindrical, or rectangular in shape. The hollow
section (18) is configured to collect the flow from the main chamber (10). In another
30 embodiment of the present disclosure, the hollow section (18) is tapered towards the outlet
line and provides an enlarged area at the outlet port (14) thereby helps in reducing the
pressure drop by acting as a funnel for the exhaust gases. The hollow section (18) at the
10
outlet port also helps in reducing noise. In yet another embodiment of the present
disclosure, the taper angle of the hollow section is in the range of 4-10○
.
[035] In an embodiment of the present disclosure, an elbow (181) is configured to be
5 attached with the hollow section (18) to safely route the exhaust gases to the environment.
[036] In an embodiment of the present disclosure, as shown in Figure 7, the outlet line
(141) is provided at certain angle to reduce the torque exerted by exhaust gas at outlet. In
another embodiment of the present disclosure, the angle of the outlet line (141) with
respect to the inlet line (131) is in the range of 0-25○
10 .
[037] In an embodiment of the present disclosure, as shown in figures 1 and 2, the safety
unit (100) comprises a Pressure Relief Valve (PRV) (17) provided within a Pressure
Relief Valve (PRV) chamber. The pressure relive valve chamber (174) is integrated with
15 the main chamber (10) through a cutout (173) in the wall of the main chamber (10). The
cutout (173) is provided to separate the main chamber (10) into two parts. One part is for
receiving dynamic pressure and the other part is for receiving static pressure where
Pressure relief valve (PRV) is provided. The shape of cutout ensures that only static
pressure inside the chamber reaches up to the PRV (17) to ensure smooth functioning of
20 the PRV. In an embodiment of the present disclosure, the shape of the cutout (173) can
be rectangle or oval or triangle or perforated etc. In another embodiment of the present
disclosure, the cutout size by inlet area ratio is in the range of 0.2-2.
[038] The PRV (17) comprises a piston (171) and a housing (172) enclosing the piston.
25 The piston (171) enables the exhaust gas to release into the environment when the force
exceeded by the pressure inside the system. In another embodiment of the present
disclosure, the PRV is configured to actuate when the build-up of pressure inside the main
chamber reaches to a certain limit. In another embodiment of the present disclosure, the
limit defined to actuate the PRV is 80% of the disclosed backpressure limit of a diesel
30 generator.
11
[039] In an embodiment of the present disclosure, as shown in Figure 8, the bypass line
(151) is provided at certain angle to achieve proper sealing of the unit with the help of
gravity. In another embodiment of the present disclosure, the angle of the bypass line
(151) with the inlet line (131) is in the range of 5○
-30○
.
5
[040] In preferred embodiment of the present disclosure, working of the Safety unit
(100) is disclosed. When the exhaust gases pass through the main chamber (10), the gases
trigger high pressure build up inside the main chamber (10). Since the flap (110) is
pivotally mounted inside the chamber (10) and further connected with the actuator (12)
10 via the flap rod (112), in such situation of high pressure build up, the actuator (12) allows
the flap (110) to move from a first position to a second position. Movement of the flap
from the first position to the second position opens the bypass port (15) to safely route
exhaust gases from the engine. Further, in case if the pressure inside the system further
increases and reaches to a certain limit, the PRV comes to action and release the exhaust
15 into the environment.
[041] Accordingly, the safety unit as disclosed in the present disclosure provides an
integrated safety system which can withstand any flow pressure of exhaust gases and
improves engine performance. Further, the safety unit as disclosed above ensure less back
20 pressure, less pressures drop and limited leakage at the exhaust system.
[042] While considerable emphasis has been placed herein on the particular features of
this disclosure, it will be appreciated that various modifications can be made, and that
many changes can be made in the preferred embodiments without departing from the
25 principles of the disclosure. These and other modifications in the nature of the disclosure
or the preferred embodiments 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 disclosure and not as a limitation.
30 EQUIVALENTS:
12
[043] The embodiments herein and the various features and advantageous details thereof
are explained with reference to the non-limiting embodiments in the description.
Descriptions of well-known components and processing techniques are omitted so as to
not unnecessarily obscure the embodiments herein. The examples used herein are
5 intended merely to facilitate an understanding of ways in which the embodiments herein
may be practiced and to further enable those of skill in the art to practice the embodiments
herein. Accordingly, the examples should not be construed as limiting the scope of the
embodiments herein.
10 [044] The foregoing description of the specific embodiments will so fully reveal the
general nature of the embodiments herein that others can, by applying current knowledge,
readily modify and/or adapt for various applications such specific embodiments without
departing from the generic concept, and, therefore, such adaptations and modifications
should and are intended to be comprehended within the meaning and range of equivalents
15 of the disclosed embodiments. It is to be understood that the phraseology or terminology
employed herein is for the purpose of description and not of limitation. Therefore, while
the embodiments herein have been described in terms of preferred embodiments, those
skilled in the art will recognize that the embodiments herein can be practiced with
modification within the spirit and scope of the embodiments as described herein.
20
[045] Throughout this specification the word “comprise”, or variations such as
“comprises” or “comprising”, will be understood to imply the inclusion of a stated
element, integer or step, or group of elements, integers or steps, but not the exclusion of
any other element, integer or step, or group of elements, integers or steps.
25
[046] The use of the expression “at least” or “at least one” suggests the use of one or
more elements or ingredients or quantities, as the use may be in the embodiment of the
disclosure to achieve one or more of the desired objects or results.
30 [047] Any discussion of documents, acts, materials, devices, articles and the like that
has been included in this specification is solely for the purpose of providing a context for
the disclosure. It is not to be taken as an admission that any or all of these matters form a
13
part of the prior art base or were common general knowledge in the field relevant to the
disclosure as it existed anywhere before the priority date of this application.
[048] The numerical values mentioned for the various physical parameters, dimensions
5 or quantities are only approximations and it is envisaged that the values higher/lower than
the numerical values assigned to the parameters, dimensions or quantities fall within the
scope of the disclosure, unless there is a statement in the specification specific to the
contrary.
10 List of Reference Numerals
Sr. No. Description
100 Safety Unit
10 Main Chamber
11 Flap Assembly
12 Actuator
13 Inlet Port
131 Inlet Line
14 Outlet Port
141 Outlet Line
15 Bypass Port
151 Bypass Line
110 Flap
111 Second Flap
112 Flap rod
14
113 Free end of Flap
114 Fixed end of Flap
16 A plurality of Seats
17 PRV
171 Piston
172 Housing
173 Cutout
174 PRV chamber
18 Hollow section
181 Elbow
15

We Claim:

1. A safety unit (100) for an exhaust system of an internal combustion engine,
the safety unit (100) comprising:
a main chamber (10),
5 an inlet port (13) attached with the exhaust system of the internal
combustion engine to receive exhaust gases from an inlet line (131),
an outlet port (14) connected with an outlet line (141) and being
configured to expel exhaust gases from the engine,
a bypass port (15); and,
10 a flap assembly (11) accommodated in the main chamber (10) and
configured to selectively regulate the direction of flow of exhaust gases
through either of the outlet port (14) or the bypass port (15).
.
2. The safety unit (100) as claimed in claim 1, wherein the flap assembly (11)
15 comprises a flap (110) configured to move between a first position and a
second position to selectively allow passage of exhaust gases through
either of the outlet port (14) or the bypass port (15).
3. The safety unit (100) as claimed in claim 1, wherein in the first position,
20 the flap (110) is configured to close the bypass port (15) so as to allow
flow of the exhaust gases from the inlet port (13) to the outlet port (14).
4. The safety unit (100) as claimed in claim 1, wherein the second position,
the flap (110) is configured to close the outlet port (14) so as to allow flow
25 of the exhaust gases from the inlet port (13) to the bypass port (15).
5. The safety unit (100) as claimed in claim 1, wherein the flap (100) is
actuable by an actuator (12).
30 6. The safety unit (100) as claimed in claim 1, wherein the flap (110)
comprises a fixed end (114) and a free end (113), the fixed end being
16
configured with a flap rod (112) mounted hingedly, such that the free end
movable swingably about the fixed end of the flap (110).
7. The safety unit (100) as claimed in claim 1, wherein the flap (110) is
5 wedge shape flap having a triangular cross section whereby free end (113)
of the flap (110) is thicker than the fixed end (114).
8. The safety unit (100) as claimed in claim 1, wherein the flap assembly (11)
selectively comprises a second flap (111) attached with the flap rod (112)
10 and configured to actuate movement of the first flap (110) between the
first and the second positions.
9. The safety unit (100) as claimed in claim 1, comprised a torsion spring
attached with the flap (110).
15
10. The safety unit as claimed in claim 1, wherein the main chamber (10)
comprises a cutout (173) provided at the wall of the main chamber (10) to
attach a pressure relief valve chamber (174).