DESC:FIELD
The present invention relates to manufacturing process of pipes more particularly related manufacturing of inlet pipes of exhaust system.
DEFINITION
Stadium-shaped configuration: The term ‘stadium-shaped’ shaped refers to a two-dimensional extended ellipse with straight sides parallel to the major axis of the ellipse.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The conventional process of manufacturing an inlet pipe includes performing a series of operations on a pair of blanks. The operations include drawing, trimming, wiping, and sizing both the blanks. Thereafter, the two drawn components are firstly tack weled and subsequently fullwelded together to define a stadium-shaped first end and a narrow cylindrical second end of the inlet pipe. The inlet pipe thus formed, is subjected to inspection to determine the faulty pieces.
It has been observed that more than 5% of the inlet pipe parts tend to warp when subjected to heat, and another 5% suffer from leakage from the welding joints. Therefore, due to such defrects/rejection ,it can be inferred that the productivity is on the lower side by at least 10%. Moreover, any dimensional variation in any of the blank, caused while performing the conventional processes, can create difficulties in assembling the blank with its complementary blank. Further, the conventional process requires a lot of machining tools, which not only consume a lot of time producing each part, but also increase the manufacturing cost and the per part cost.
There is therefore felt a need of a procedure that alleviates the aforementioned drawbacks.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a process for manufacturing inlet pipes for exhaust systems.
Another object of the present disclosure is to provide a process that allows manufacturing of an inlet pipe in relatively lesser steps and time.
Yet another object of the present disclosure is to provide a process for manufacturing inlet pipes for exhaust systems in a cost-effective manner.
Still another object of the present disclosure is to provide a process, for manufacturing inlet pipes for exhaust systems, which eliminates warpage, leakage or failure of the inlet pipe.
Another object of the present disclosure is to provide a process for manufacturing inlet pipes for exhaust systems with minimal rejection rate and improves productivity.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present invention discloses a method of manufacturing inlet pipe for exhaust systems. The inlet pipe is defined by a stadium-shaped first end portion, a circular shaped second end portion and a transition portion configured to connect the first end portion with the second end portion. The method comprises steps of selecting a pipe of circular cross-section having circumference smaller than the first end portion of the inlet pipe and having circumference greater than the circumference of the second end portion of the inlet pipe;
expanding first end of the pipe by end forming to form the stadium shaped first end portion at first end of the pipe; reducing diameter of the pipe to desired diameter to form the circular second end portion at second end of the pipe.
According to an embodiment of present invention, in the expanding step the the first end of the pipe 10 is expanded in the range of 10%-18% to form the stadium shaped first end portion of desired dimension without failure of the pipe; and in the reducing step, diameter of the second end of the pipe is reduced in the range of 10%-18% to form the circular second end portion of desired diameter without failure of the pipe.
According to an embodiment of present invention, the expanding step is carried out in at least two stages to obtain the stadium shaped first end portion of desired dimensions.
According to an embodiment of present invention, the reducing step is carried out in at least two stages to obtain the circular shaped second end portion of desired dimensions.
According to an embodiment of present invention, the pipe is selected from pipe having diameter in the range of 120mm-135mm.
According to an embodiment of present invention, the pipe is selected from pipe having diameter in the range of 120mm-135mm and thickness in the range of 1.5 mm to 2.5mm.
According to another embodiment of present invention, the method comprises step of piercing at least two holes on the second end portion .
According to an embodiment of present invention, before the expanding step, the diameter of the pipe is less than major diameter of the stadium-shaped first end portion and greater than minor diameter of the stadium-shaped first end portion .
According to an embodiment of present invention, material of said pipe (10) is selected form the group consisting of stainless steel, aluminized steel, SS439, SS409, SS441 and aluminium.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A process, of the present disclosure, for manufacturing inlet pipes for exhaust systems will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a flowchart depicting the process of the present disclosure;
Figure 2 illustrates deformation of a pipe into the inlet pipe formed by the process of the present disclosure;
Figure 3 illustrates an isometric view of the inlet pipe formed by the process of Figure 1; and
Figure 4 illustrates a front view of the inlet pipe of Figure 3;
Figure 5 illustrates a cross-sectional view of the first end portion of the inlet pipe of Figure 3; and
Figure 6 illustrates a cross-sectional view of the second end portion of the inlet pipe of Figure 3.
LIST OF REFERENCE NUMERALS
10 pipe before being formed
d diameter of pipe 10
A first end of pipe 10
B second end of pipe 10
100 inlet pipe for exhaust system
105 first end portion (stadium shaped)
d1 major diameter of stadium shaped first end portion 105
d2 minor diameter of stadium shaped first end portion 105
110 second end portion ( circular shaped)
120 hole
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including”, “includes” and “having” are open-ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
A preferred embodiment of a process (200) for manufacturing inlet pipe (100) for exhaust systems will now be described in detail with reference to Figure 1 through Figure 6. The preferred embodiment does not limit the scope and ambit of the present disclosure.
An inlet pipe is defined by a stadium-shaped first end portion (105), and a transition portion configured to connect said first end portion (105) with said second end portion (110), as shown in Figure 4 through Figure 6.
In a preferred embodiment, the process (200) includes a first step (205) of selecting a pipe (10) of circular cross-section having circumference smaller than desired circumference of said first end portion (105) of said inlet pipe (100) and having circumference greater than the desired circumference of said second end portion (110) of said inlet pipe (100). In another embodiment, the pipe may have a diameter equal to the diameter of the desired diameter of the second end portion (110).
The process (200) includes a second step (210) of expanding a first end (A) of said pipe (10) by end forming to form said stadium shaped first end portion (105) at first end (A) of said pipe 10.
Thus, the second step (210) ensures alteration of the pipe from the original configuration to the desired stadium-shaped configuration.
The process (200) includes a third step (220) of reducing diameter of said pipe (10) to desired diameter by end forming to form said circular second end portion (105) at a second end (B) of said pipe (10).
Formation of first end portion and second ned portion defines a neck portion between said first and said second portion having conical shape cross section
The inlet pipe (100) thus formed by the process (200) of the present disclosure, has a monolithic configuration which reduces the rejection rate to less than 1%, and completely eliminates the possibilities of warpage or leakage due to the absence of any welding joint. Further, when compared to conventional processes, the process (200) of the present disclosure includes fewer steps which therefore decreases the manufacturing time by approximately 45%. Moreover, since the process (200) is focused on manufacturing the exhaust from a single pipe, the dimensional variations and productivity losses are also eliminated.
As compared to conventional tooling cost, the tooling of the process (200) of the present disclosure is cheaper by 65%, while per part cost is also cheaper by approximately 12%.
In an exemplary embodiment, as shown in Figure 2, a stainless steel pipe of circular cross-section having a diameter of 127mm and length of 230mm is formed in accordance with the process (200) of the present disclosure to form an inlet pipe (100). A first end (A) of the pipe is first expanded along an operative first direction with the help of the expanding tool to form the first end portion (105) without failure of the pipe. Thereafter, the diameter of a second end (B) of the pipe (10) is reduced with the help of end forming tool to form the second end portion (110) without failure of the pipe. The major diameter (d1) (length of the longer span) of the first end portion (105) of the thus formed inlet pipe is 183mm, and the minor diameter (d2) (the width of the shorter span ) of the first end portion (105) is 83mm. On the other hand, the diameter of the second end portion (110) is 114mm. The length of the inlet pipe is 211mm.
In an exemplary embodiment, circumference of stadium shaped first end portion is around 461mm and circumference of second end portion is around 359mm. Considereing the selected pipe (10) of diameter 127mm, circumference at both ends (A) and (B) before end forming operation is around 399mm. According to this embodiment, during end forming operation, the circumference of the circular pipe of diameter 127mm is expanded by around 15.5% at end A and reduced by around 10% at end B without failure of the pipe (10).
In another embodiment, at least one hole (120) is pierced on the second end portion (110) of the inlet pipe (100). In an embodiment, two holes (120) is pierced on the second end portion (110) of the inlet pipe (100).
In another embodiment the inlet pipe (100) may be manufactured from an aluminized steel, carbon steel, SS439, SS409, SS441 or aluminium.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of process for manufacturing inlet pipes for exhaust systems, which:
• allows manufacturing of an inlet pipe in relatively lesser steps and time;
• allows manufacturing of an inlet pipe in a cost-effective manner;
• eliminates warpage or leakage of the inlet pipe; and
• allows manufacturing of an inlet pipe with minimal rejection rate.
The foregoing disclosure has been described with reference to the accompanying embodiments which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following 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 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.
The foregoing description of the specific embodiments 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 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.
Any discussion of materials, implants, articles or 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 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.
The numerical values mentioned for the various physical parameters, dimensions 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.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure 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.
,CLAIMS:WE CLAIM:
1. A method of manufacturing inlet pipe (100) for exhaust systems, said inlet pipe (100) defined by a stadium-shaped first end portion (105), a circular shaped second end portion (110) and a transition portion configured to connect said first end portion (105) with said second end portion (110),
said method comprising steps of:
• selecting a pipe (10) of circular cross-section having circumference smaller than said first end portion (105) of said inlet pipe (100) and having circumference greater than the circumference of said second end portion (110) of said inlet pipe (100);
• expanding a first end (A) of said pipe (10) by end forming to form said stadium shaped first end portion (105) at first end (A) of said pipe (10);
• reducing diameter of said pipe (10) to desired diameter to form said circular second end portion (105) at a second end (B) of said pipe (10).

2. The method as claimed in claim 1, in said expanding step the said first end (A) of said pipe 10 is expanded in the range of 10%-18% to form said stadium shaped first end portion (105) of desired dimension without failure of said pipe 10; and
in said reducing step, diameter of said second end (B) of said pipe (10) is reduced in the range of 10%-18% to form said circular second end portion (105) of desired diameter without failure of said pipe 10.

3. The method as claimed in claim 1, said expanding step is carried out in at least two stages to obtain said stadium shaped first end portion (105) of desired dimensions.

4. The method as claimed in claim 1, said reducing step is carried out in at least two stages to obtain said circular shaped second end portion (110) of desired dimensions.

5. The method as claimed in claim 1, said pipe (10) is selected from pipe having diameter in the range of 120mm-135mm.

6. The method as claimed in claim 1, said pipe (10) is selected from pipe having diameter in the range of 120mm-135mm and thickness in the range of 1.5 mm to 2.5 mm.

7. The method as claimed in claim 1, said method comprises step of piercing at least two holes (120) on said second end portion (110).

8. The method as claimed in claim 1, before said expanding step, the diameter (d) of said pipe (10) is less than major diameter (d1) of said stadium-shaped first end portion (105) and is greater than minor diameter (d2) of said stadium-shaped first end portion (105).

9. The method as claimed in claim 1, material of said pipe (10) is selected form the group consisting of stainless steel, aluminized steel, SS439, SS409, SS441 and aluminium.

Dated this 26th day of July, 2023

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K. DEWAN & CO.
Authorized Agent of Applicant