Description:FIELD OF INVENTION

The present invention relates to a silencer for the exhaust system, having improved corrosion performance. In particular, the present invention relates to a silencer skin panel in exhaust system, and having improved corrosion performance. More particularly, the present invention relates to a powder coated steel silencer with multi-segment/tube skin panel to improve the corrosion resistance thereof.

BACKGROUND OF THE INVENTION

Primarily, a silencer is used to send exhaust gases from the internal combustion engine (ICE) to the atmosphere after filtering the restricted elements and gases which are generated after burning of fuels therein. A continuous operation of IC engine results in increasing the temperature of the silencer skin. Parts like the silencer are visible to the customer and any drop in its performance directly affects the vehicle performance and vehicle may become stand still. Therefore, high-temperature corrosion-resistance is very crucial for designing the silencers.

A silencer should have a heat resistant powder coating to withstand temperatures from 350 to 4000C as well as to improve the corrosion-resistance thereof. However, when the exhaust gas temperature gets reduced while going to the top location of the silencer, and the silencer skin temperature also goes down from 350 to 2500C at the bottom location to top location thereof respectively. Because of a change in the silencer skin temperature, the heat-resistance powder coating becomes inactive in the areas where temperature drops from 300 and 2500C, due to which the corrosion-resistance does not remain good at the middle and top portion of the silencer.
As the thermal conductivity of steel is constant, it is difficult to maintain a uniform temperature of the silencer skin because of the inner temperature variations.

Therefore, there is a need for gradually reducing the steel sheet thickness from the bottom to the top portions of the silencer for maintaining a uniform temperature of the silencer skin from the bottom to top portions thereof.

DISADVANTAGES OF THE PRIOR ART

Almost all the existing newly manufactured tractors of the applicant show corrosion in early stage in operation thereof. This leads to substantial costs of replacement of silencers under warranty.

The process of increasing the corrosion-resistance in the applicant’s tractors includes the following process:

• Shot blasting.
• Metalizing.
• Powder coating.
• Baking.

Another option is to use a ceramic coating on the silencers to reduce the corrosion thereof.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:
An object of the present invention is to provide a silencer having different sheet thicknesses and/or lengths for improving the corrosion performance thereof.

Another object of the present invention is to provide a silencer having different sheet thicknesses and/or lengths for a uniform silencer skin temperature to obtain an improved corrosion resistance thereof.

Still another object of the present invention is to provide a silencer having different sheet thicknesses and/or lengths for a uniform silencer skin temperature to obtain an improved corrosion performance thereof.

Yet another object of the present invention is to provide a multi-segment silencer having different sheet thicknesses and/or lengths for improving the corrosion resistance thereof.

Still further object of the present invention is to provide a multi-tube silencer having different sheet thicknesses/and/or lengths for improving the corrosion performance thereof.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

DESCRIPTION OF THE INVENTION

The multi-segment or multi-tube silencer configured in accordance with the present invention has variable sheet thickness in different segments for improving the corrosion performance thereof.
It is well-known that the equation for thermal conductivity K is as given below:
K = Q*t/A* ΔT
K : Thermal conductivity,
Q : Amount of heat transferred,
t : Distance between the two planes or thickness of sheet,
A : Surface area, and
ΔT: (T1-T2), wherein,
T1 – Inner surface temperature, and
T2 – Outer surface temperature.
The thermal conductivity of steel is measured at approximately 45 W/(mK).

Segment K A ΔT Q Sheet thickness
t (mm) t (mm) Inner radius
r (mm) Error Finalized thickness
(mm)
1 45 0.02826 200 42390 0.006 6 45 6

2 45 0.02826 150 42390 0.0045 4.5 46.5 0.00015
45 0.02826 150 42390 0.00465 4.65 46.35 -1.5E-05
45 0.02826 150 42390 0.004635 4.635 46.365 1.5E-06 4.6
45 0.02826 150 42390 0.0046365 4.6365 46.3635 -1.5E-07
45 0.02826 150 42390 0.0046364 4.63635 46.36365

3 45 0.02826 100 42390 0.003 3 48
45 0.03014 100 42390 0.0032 3.2 47.8 0.0002
45 0.03002 100 42390 0.0031867 3.1866667 47.81333333 -1.333E-05
45 0.03003 100 42390 0.0031876 3.1875556 47.81244444 8.88889E-07 3.18

The above silencer is manufactured by one of the following methods:

1. Multiple tubes are joined one over the other and maintaining the variable thickness in this silencer and assembling them together by welding.

2. Three different thickness steel plates (6.0 mm, 4.6 mm and 3.2 mm). welded together and the silencer is formed into a multi-segment tube.
SUMMARY OF INVENTION

In accordance with the present invention, there is provided a silencer with improved corrosion resistance or corrosion performance thereof, the silencer comprises a skin externally coated with powder coating and having the thickness thereof decreasing from the inlet end to the outlet end for maintaining a uniform temperature thereof.

Typically, the silencer comprises a plurality of portions assembled, e.g. by welding them together or pressing one over the other, along the length, from the inlet end to the outlet end thereof.

Typically, the silencer comprises three annular segments of the same or different length/s and/or the same or different thickness/es and having an inlet-end and an outlet-end.

Typically, each of the plurality of portions comprises an annular segment of the same length but different thickness.

Typically, each of the plurality of portions comprises an annular segment of a different lengths and thicknesses.

Typically, the annular segments of the same or different length/s are sequentially welded at least at one end, along the length, from the inlet-end to the outlet-end thereof.

Typically, the inlet-end comprises the annular segment of the highest thickness and the outlet-end comprises the annular segment of the least thickness.

Typically, the silencer comprises three tubular portions of the different lengths and/or different thicknesses and having an inlet-end and an outlet-end.

Typically, each of the plurality of portions comprises a different length and thickness.

Typically, the tubular portions are welded together one inside the other and welded at least at one end along the length, from the inlet end to the outlet end thereof.

Typically, the tubular portions are sequentially pressed into the other, along the length of the silencer from the inlet-end to the outlet-end thereof.

Typically, the inlet-end comprises the tubular portion of the highest thickness and the outlet-end comprises the tubular portion of the least thickness.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described in the following with reference to the accompanying drawings.

Figure 1a shows a conventional new silencer of the tractor in its original condition.

Figure 1b shows the corrosion of the silencer of Figure 1a subsequent to continuous operation thereof over time.

Figure 1c shows a tractor T fitted with a conventional silencer S in its original condition.

Figure 1d shows an enlarged perspective view of the conventional silencer S of Figure 1c.

Figure 2a shows another perspective view of the conventional silencer of the Fig. 1d.

Figure 2b shows a cross-sectional view of the conventional silencer of Fig. 2a.

Figure 2c shows an enlarged cross-sectional view of the conventional silencer of Fig. 2b.

Figure 3a shows a perspective view of the silencer improved in accordance with the present invention.

Figure 3b shows a cross-sectional view of the silencer of Figure 3a.

Figure 3c shows an enlarged cross-sectional view of the silencer of Figure 3b.

Figure 4 shows a typical tractor with a conventional silencer and the temperature variations observed in various portions of the silencer skin during a continuous operation of the silencer.

Figure 5 shows a schematic arrangement of a conventional silencer having a cross-section with uniform steel sheet thickness and showing the temperature gradient along its length during actual operation thereof.

Figure 6a shows the schematic arrangement of a conventional silencer of Figure 5 and Figure 6b shows an embodiment of the silencer configured in accordance with the present invention and having its skin made of gradually reducing steel-sheet thickness.

Figure 7a shows the schematic arrangement of a conventional silencer of Figure 5 and Figure 7c shows an embodiment of the silencer configured in accordance with the present invention, e.g. a multi-tube silencer.

Figure 8a shows the schematic arrangement of a conventional silencer of Figure 3 and Figure 8b shows another embodiment of the silencer configured in accordance with the present invention, e.g. a multi-segment.

Figure 9 shows the schematic arrangement of a conventional silencer (a) of Figure 3 and an embodiment of a multi-tube silencer (c) configured in accordance with the present invention.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, a silencer configured in accordance with the present invention, e.g. multi-segment or multi-tube silencer for improving the corrosion performance and configured in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention.

Figure 1a shows a conventional new silencer S of the tractor S in its original condition.

Figure 1b shows the corrosion in the silencer S of Figure 1a of the tractor T after a continuous operation thereof, e.g. after 3 months of its operation.

Figure 1c shows a tractor fitted with a conventional silencer in its original condition.

Figure 1d shows an enlarged perspective view of the conventional silencer of Figure 1c.
Figure 2a shows another perspective view of the conventional silencer S of Figure 1d and having a sheet metal skin Sk of uniform thickness. It is also marked with a section line A-A to be explained below in details.

Figure 2b shows a cross-sectional view of the conventional silencer S of Figure 2a depicted across the section line A-A marked therein.

Figure 2c shows an enlarged cross-sectional view of the main body of the conventional silencer S of Figure 2b and depicting a sheet metal skin Sk of a uniform thickness t.

Figure 3a shows a perspective view of the silencer S1 improved in accordance with the present invention depicted across the section line A-A marked therein.

Figure 3b shows an enlarged cross-sectional view of the main body of the silencer S1 of Figure 3a across section line A-A and depicting a sheet metal skin Sk1 of variable thickness.

Figure 3c shows an enlarged cross-sectional view of silencer S1 of Figure 3b and depicting the sheet metal skin Sk1 of different thicknesses on various portions of the skin Sk1 thereof, e.g. skin thickness T1 in the top portion, skin thickness T2 at the middle portion and skin thickness T3 at the bottom portion. There is a gradual reduction in the silencer skin Sk1 of steel sheet thickness, from bottom to top portions thereof, i.e. T1 < T2 < T3, which helps in maintaining a uniform temperature of the skin Sk1 or an acceptable variation of 500C from the bottom to top portions thereof.

Figure 4 shows a typical tractor T fitted with a conventional silencer S and the temperature variations observed in various portions of the silencer skin during a continuous operation of the silencer. The exhaust gases enter this silencer at 4460C, rises upwards and the temperature at the skin thereof was observed gradually reducing from 3300C at the bottom portion to 3100C in the middle portion, and 2550C at the top portion thereof. The temperature 2600C at the entry of the exhaust pipe connected to the top portion of the skin is reduced to 2390C and exhaust is finally released at 2300C from exhaust pipe open to the atmosphere.

Figure 5 shows a schematic arrangement of a conventional silencer S having a cross-section with a skin Sk of uniform steel sheet thickness and showing a temperature gradient of 5000C at the bottom to 4000C in the middle and 3000C at the top portion thereof its length during actual operation thereof. The hot exhaust gases from the engine Exi enter from the bottom and cooled exhaust gases Exo exit from the top end thereof. The silencer S is made of steel sheet SS of thickness t and has a skin Sk externally coated with powder coating PC.

Figure 6a shows the schematic arrangement of a conventional silencer of Figure 5 and Figure 6b shows an embodiment of the silencer configured in accordance with the present invention and having skin with gradually and uniformly reducing sheet thickness (t1) from the bottom portion to the thickness (t2) at the top portion thereof. It is observed that this embodiment of this silencer has a uniform skin temperature of 2500C.

Figure 7a shows the schematic arrangement of a conventional silencer of Figure 5 and Figure 7b shows an embodiment of the silencer configured in accordance with the present invention, e.g. multi-tube silencer having multiple tubes, e.g. three tubes (T21, T22, T23) made of steel sheets of different thicknesses (t11, t12, t13) assembled together by securely fixing one over the other, to form the multi-tube silencer. It is observed that this embodiment of this silencer also has a uniform skin temperature of 2500C.

Figure 8a shows the schematic arrangement of a conventional silencer of Figure 5 and Figure 8b shows an embodiment of the silencer configured in accordance with the present invention, e.g. a multi-segment silencer having multiple segments of same or different lengths (L1, L2, L3) of different thicknesses assembled together by welding process. It is observed that even this embodiment of this silencer has a uniform skin temperature of 2500C.

Figure 9 shows the schematic arrangement of a conventional silencer (a) of Figure 5 and a multi-tube silencer (c) embodiment configured in accordance with the present invention and having three tubes (T21, T22, T23) made of steel sheets of same/different lengths (L1, L2, L3) and/or different thickness (t21, t22, t23) (e.g. 6.0 mm, 4.6 mm and 3.2 mm) joined by welding one over the other.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The multi-segment/tube silencer with different steel-sheet thicknesses and/or lengths for improving the corrosion resistance/performance thereof, and configured in accordance with the present invention offers the following advantages:
• Demonstrates uniform temperature of the silencer skin.
• Uniform silencer skin temperature provides improved corrosion resistance thereof.
• Facilitates in configuring different capacity of silencers.

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 of the disclosed embodiments.

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. The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person in the art would readily recognize that these embodiments can be applied with modifications possible within the spirit and scope of the present invention as described in this specification by making innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies, in terms of their size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

These relative terms are for convenience of description and do not require that the corresponding apparatus or device be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected”, refer to a relationship, wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. , Claims:We claim:

1. A silencer (S1) with improved corrosion resistance or corrosion performance thereof, said silencer comprises a skin (Sk1) externally coated with powder coating (PC) and having the thickness (t1, t2) thereof decreasing from the inlet end (Exi) to the outlet end (Exo) for maintaining a uniform temperature thereof.

2. The silencer (S1) as claimed in claim 1, wherein said silencer (S1) comprises a plurality of portions assembled, e.g. by welding them together or pressing one over the other along the length, from the inlet end (Exi) to the outlet end (Exo) thereof.

3. The silencer (S1) as claimed in claim 2, wherein said silencer (S1) comprises three annular segments of the same or different length/s (L1, L2, L3) and/or the same or different thickness/es and having an inlet-end (Exi) and an outlet-end (Exo).

4. The silencer (S1) as claimed in claim 3, wherein each of said plurality of portions comprises an annular segment of the same length (L1, L2, L3) but different thicknesses.

5. The silencer (S1) as claimed in claim 2, wherein each of said plurality of portions comprises an annular segment of different lengths (L1, L2, L3) and thicknesses (t11, t12, t13).

6. The silencer (S1) as claimed in claim 4 or 5, wherein said annular segments of the same or different length/s (L1, L2, L3) are sequentially welded at least at one end, along the length, from said inlet-end (Exi) to outlet-end (Exo) thereof.

7. The silencer (S1) as claimed in claim 6, wherein said inlet-end (Exi) comprises the annular segment of the highest thickness and said outlet-end (Exo) comprises the annular segment of the least thickness.

8. The silencer (S1) as claimed in claim 2, wherein said silencer (S1) comprises three tubular portions (T21, T22, T23) of the different lengths and/or different thicknesses and having an inlet-end (Exi) and an outlet-end (Exo).

9. The silencer (S1) as claimed in claim 8, wherein each of said plurality of portions (T21, T22, T23) comprises a different length and thickness (t11, t12, t13).

10. The silencer (S1) as claimed in claim 9, wherein said tubular portions (T21, T22, T23) are welded together one inside the other and welded at least at one end along the length, from said inlet-end (Exi) to said outlet-end (Exo) thereof.

11. The silencer (S1) as claimed in claim 9, wherein said tubular portions (T21, T22, T23) are sequentially pressed into the other along the length of said silencer (S1) from said inlet-end (Exi) to said outlet-end (Exo) thereof.

12. The silencer (S1) as claimed in claim 10 or 11, wherein said inlet-end (Exi) comprises the tubular portion (T23) of the highest thickness (t13) and said outlet-end (Exo) comprises the tubular portion (T21) of the least thickness (t11).

Dated this 17th day of March 2023.

Digitally / e-Signed by:

(SANJAY KESHARWANI)
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA-2043.