Description:TITLE: “METHOD FOR USING CO2 WELDING TORCHES IN WELDING FOR OBTAINING MORE FILLET DEPOSITION AND AN APPARATUS OF DOUBLE TORCH HOLDING UNIT”

FIELD OF INVENTION:

[001] The present invention is related to the process of welding to form structural ‘I’ beam which is involved in erection of thermal power plant. More particularly, the invention relates to automatic twin torch CO2 welding station which is being used in simultaneous welding of the fins to the either sides of the hanger tube which is used in re-heater coil assembly of thermal power plant. This invention is about the utilisation of the two CO2 welding torches of two CO2welding machine inverters of this machine in simultaneous welding at the same location in ‘I’ beam welding to obtain more weld fillet deposition.

BACKGROUND OF THE INVENTION:

[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[003] The automatic twin torch CO2 welding stations involves two welding torches in welding and joining two fins on either sides of the hanger tube simultaneously at the same time. The system consists of two sets of rack and pinion assemblies, one is on the ‘X’ axis for vertical alignment and other one is on the ‘Y’ axis for horizontal alignment of two torches. The rack fixed in the ‘X’ axis is provided with one pinion assembly which enables the overall alignment of the torch unit in vertical direction. Whereas the rack fixed in the ‘Y’ axis is provided with two pinion assemblies which enables horizontal alignment of two independent torches. So far the apparatus is involved in utilizing two CO2 welding torches in simultaneously welding on two different locations at the same time. In contrast, the present invention complies with utilisation of two CO2 welding torches in welding in same welding point in order to obtain more fillet deposition.

OBJECTS OF THE INVENTION:

[004] It is therefore an object of the present invention to propose a method and apparatus of utilising two CO2 welding torches from two separate CO2 welding machine to weld simultaneously at the same time in same welding location.

[005] Another object of the present invention is to obtain more fillet deposition by utilising two CO2 welding torches from two separate CO2 welding machine to weld simultaneously at the same time in same welding location.

[006] Yet another object of the present invention is to propose development of optimum CO2 welding parameters for utilising two CO2 welding torches from two separate CO2 welding machine to weld simultaneously at the same time in same welding location.

[007] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION:

[008] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method 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 part of the claimed disclosure.

[009] Involvement of multiple welding torches in simultaneous welding is more common. In such cases all the welding torches in simultaneous welding are involved in independent welding locations i.e., each one in separate welding location. This invention implies the derivation of welding method that involves two separate welding torches involved in welding at the same welding location.

[0010] This invention is carried out in order to obtain more fillet deposition in the welding where there is minimum filler wire being used. Here, in automatic twin torch CO2 welding station, where ‘I’ beam welding is being performed, CO2 welding process is carried out. In this CO2 welding process, the thickness of the filler wire used is 1.6mm only. Using this 1.6mm filler wire in single CO2 welding torch, the maximum weld fillet that can be obtained is only 6 to 8 mm. On the other hand, the weld fillet requirement is up to 12 to 21 mm which varies according to the thickness of the web plate used in the ‘I’ beam.

[0011] According to the present invention, there is provided Method for utilization of CO2 welding torches in welding for obtaining more fillet deposition comprising steps of:

- Welding to form structural ‘I’ beam for erection of thermal power plant, wherein automatic twin torch CO2 welding station is used in simultaneous welding of fins to either sides of the hanger tube at the same welding location which is used in re-heater coil assembly of thermal power plant;

- maintaining the working angle of the two torches to 25 degrees from either sides of the job that it forms an included angle of 40 degrees to each other;

- maintaining the voltage between 25V to 27V that the arc area covered by the two individual CO2 welding torches not to overlap with each other by maintaining the weld pool as common.

[0012] Further according to the invention, there is provided an apparatus of double torch holding unit for holding two CO2 welding torches (10 & 11) comprises of at least two racks (2 & 3) and three pinion assemblies (4, 5 & 6), wherein said rack (2) and pinion assembly (4) are assembled in the vertical ‘X’ axis, and said another rack (3) and other two pinion assemblies (5 & 6) are assembled in horizontal ‘Y’ axis, in which the rack and pinion assemblies at the horizontal ‘Y’ axis are assembled in-between an inverted ‘U’ bracket (7), wherein the two twisted flat strip assemblies (8 & 9) are fixed to the two pinion assemblies (3B & 3C) in the horizontal ‘Y’ axis in which two CO2 welding torches (10 & 11) are made to hold.

[0013] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0014] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0015] 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 by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:

[0016] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-

Figure1– Shows an apparatus of double torch holding unit capable of holding two CO2 welding torches according to the present invention.

Figure 2 – Shows the welding torch angle setting in accordance with the job (‘I’ Beam) to obtain perfect fillet deposition in accordance with the invention.

[0017] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENTOF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:

[0018] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described 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 is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0019] The present invention makes a disclosure regarding a technology pertaining to an invention directing to method for using CO2 welding torches in welding for obtaining more fillet deposition and an apparatus of double torch holding unit.

[0020] Design of the apparatus of double torch holding unit may be discussed herein below:
[0021] Referring to figure1, the apparatus is of double torch holding unit which is capable of holding two CO2 welding torches (10 & 11). The whole apparatus is made to be held rigidly in a cantilever support (1). The apparatus comprises of two racks (2 & 3) and three pinion assemblies (4, 5 & 6). Said one rack (2) and one pinion assembly (4) are assembled in the vertical ‘X’ axis, and another rack (3) and other two pinion assemblies (5 & 6) are assembled in horizontal ‘Y’ axis. The rack and pinion assemblies at the horizontal ‘Y’ axis are assembled in-between an inverted ‘U’ bracket (7). Two twisted flat strip assemblies (8 & 9) are fixed to the two pinion assemblies (3B & 3C) in the horizontal ‘Y’ axis in which two CO2 welding torches (10 & 11) are made to hold.

[0022] The welding torch angle setting is in accordance with the job (‘I’ Beam), for which reference may be made to Fig.2.
[0023] As shown in fig.2, the included angle of the job (1) to be welded (‘I’ beam) is 90 degrees, which is being located and welded at ‘V’ position. As per the invention, here two CO2 welding torches (2 & 3) are subjected in welding process at one point which are tilted to the working angle of 25 degrees form the surface of the job (‘I’ beam), so that it forms an included angle of 40 degrees to each other.
[0024] This welding torch set up with appropriate welding amperage and voltage enables the successful invention of new methodology of utilization of two CO2 welding torches involved in welding at the same time in same point to obtain more fillet deposition.

[0025] In order to obtain more fillet deposition, a new method of CO2 welding has been invented. By this invention two CO2 welding torches from two separate CO2 welding inverters are involved to weld at the same time and at the same location. In this new welding method, the weld pool would be maintained as common to both the welding torches, in which filler wires from both the welding torches would provide at the same point so that the resultant fillet obtained would be more i.e., twice or even thrice than that of old single torch welding method.

[0026] In order to obtain a successful outcome by this welding method, there are two parameters to be derived. One is regarding the torch angle and another is regarding welding arc formation. First two parameters to be considered are regarding the torch angle i.e., working angle and travel angle. The travel angle is most common in many welding method i.e., 5 to 15 degrees which enables good deposition and to obtain splatter free welding.

[0027] In case of working angle, normally it is 90 degrees in case of butt joint and 45 degrees in case of angle joint. Here, the ‘I’ beam welding is of angle welding process in which 45 degree has to be chosen if single welding torch is utilized. Since single welding torch utilization is not sufficient to obtain the required fillet deposition of 12 to 21 mm, the new invention of utilizing two welding torches has been introduced by which the nominal welding angle of 45 degrees won’t work.

[0028] Here, the two torches are tilted to the working angel of 25 degrees from either sides of the job so that it forms an included angle of 40 degrees to each other. By this arrangement tip of the two welding torches meet at an angle of 40 degrees. When both the torches are made to weld at the same time, filler wire provided through both the torches forms a fillet of 12 to 21 mm as required. The specific level of fillet can be obtained by adjusting the travel speed accordingly.

[0029] Another two parameters to be derived regarding welding arc formation i.e., the Amperage and Voltage. The Amperage and the wire feed are interlinked to one another which is the in-built setting on the welding machine inverter itself which is 275A to 300A. While considering the voltage, it is the major factor which decides the penetration and parent metal bonding. It can be visually analyzed by observing the arc formed at the tip of the welding torch while welding.

[0030] In this invention the voltage has to be more precisely observed since two welding torches are involved at the same time maintaining the process at the same welding spot. Here, in this invention the distance between the arc formed at the tip of both the welding torches are precisely maintained not to meet with each other. If done so the frequency of the arc would be rapidly varying, affecting the formation of weld fillet which leads to even porosity defect. More the voltage, the arc area covered is more. Meanwhile lesser the voltage, the arc area covered will be less. The normal voltage fixed while using two welding torches is 25V to 27V. Therefore, both the arc formed at the tip of the both the welding torches are maintained to travel separately without overlapping whereas the welding pool is maintained to be common for both the torches.
[0031] As such this present invention of involving two CO2 welding torches to weld at the same welding spot maintaining the same welding pool is achieved successfully.

ADVANATGES OF THE INVENTION:
- Obtain more fillet formation using normal CO2 welding torch and ⁓1.6mm filler wire instead for procuring special kind of torch and filler wire to meet out the purpose.
- Cycle time has been reduced drastically, since the fillet formation obtained in three times of repetitive welding is obtained in single weld time.
- As a result Productivity is increased to a great extent.
- Manual welding is now converted to a semi-automatic welding which eliminates the requirement of skilled manual welders.
- Hazardous welding atmosphere is totally avoided.
- Total invention has been carried out as in-house establishment.
- Optimum utilization of available resources has been promoted.
- Operator fatigue is reduced to great extent.

WORKING OF THE INVENTION:
[0032] By this invention, two CO2 welding torches have been subjected to weld in same welding spot (“I” beam web welding) maintaining the same weld pool which is totally a new method of welding process.
[0033] In “I” beam web welding, the required fillet formation is 12mm to 21mm which varies according to the thickness of the web. But maximum fillet obtained by the CO2 welding process is ⁓ 6 mm only since the welding torch capable to utilise the filler wire of thickness ⁓1.6mm only. Even if the welding speed and filler wire feed is adjusted, the required fillet formation couldn’t be obtained and if tried as such results with bad weld quality. Hence the filler wire thickness has to be increased parallel with the size of the welding torch which has to be procured newly.
[0034] Here is our new invention of methodology of utilising two CO2 welding torches at the same welding spot gives a successful result more than expectation. In “I” beam web and flange welding, two CO2 welding torches are subjected to weld at the same time in same spot where web and flange of the “I” beam are joined together. Here, both the CO2 welding torches are intended to weld maintaining a definite angle to each other as well to the welding object (web and flange of “I” beam). The distance between the two tips of the welding torches is maintained, as such the welding arc formed at the tip of the torch does not get overlapped. In this case, the amperage and voltage plays a main role in maintaining the size of the arc at both the tips of the welding torches.
[0035] The apparatus invented for holding the two CO2 welding torches is made with unique design by which the angle as well the distance between the welding torches are maintained in a definite manner throughout the welding process. Also the apparatus is provided with rack and pinion arrangements both in vertical ‘X’ axis and horizontal ‘Y’ axis so that the welding torches can be aligned according to the variations in the welding spot.

[0036] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0037] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0038] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0039] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0041] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0042] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
, Claims:WE CLAIM:

1. Method for utilization of CO2 welding torches in welding for obtaining more fillet deposition comprising steps of:
- welding to form structural ‘I’ beam for erection of thermal power plant, wherein automatic twin torch CO2 welding station is used in simultaneous welding of fins to either sides of the hanger tube at the same welding location which is used in re-heater coil assembly of thermal power plant;
- maintaining the working angle of the two torches to 25 degrees from either sides of the job that it forms an included angle of 40 degrees to each other;
- maintaining the voltage between 25V to 27V that the arc area covered by the two individual CO2 welding torches not to overlap with each other by maintaining the weld pool as common.

2. The method as claimed in claim 1, wherein the weld pool is maintained as common to both the welding torches, in which filler wires from both the welding torches provide at the same point that the resultant fillet obtained is more i.e., twice or even thrice than that of old single torch welding method.

3. The method as claimed in claim 1 or 2, which involves two parameters, which include torch angle and welding arc formation, in which the torch angle includes working angle and travel angle, wherein the travel angle is 5 to 15 degrees enabling good deposition and splatter free welding.

4. The method as claimed in claims 1-3, wherein the two torches are tilted to the working angel of 25 degrees from either sides of the job that it forms an included angle of 40 degrees to each other, in which by this arrangement tip of the two welding torches meet at an angle of 40 degrees, wherein when both the torches are made to weld at the same time, filler wire provided through both the torches forms a fillet of 12 to 21 mm.

5. The method as claimed in claims 1-4, wherein the welding arc formation involves Amperage and Voltage, in which the Amperage and the wire feed are interlinked to one another which is the in-built setting on the welding machine inverter itself which is 275A to 300A.

6. The method as claimed in claims 1-5, wherein the distance between the arc formed at the tip of both the welding torches is maintained not to meet with each other, wherein the normal voltage fixed while using two welding torches is 25V to 27V that both the arc formed at the tip of the both the welding torches are maintained to travel separately without overlapping and the welding pool is maintained to be common for both the torches.

7. An apparatus of double torch holding unit for holding two CO2 welding torches (10 & 11) comprises of at least two racks (2 & 3) and three pinion assemblies (4, 5 & 6), wherein said rack (2) and pinion assembly (4) are assembled in the vertical ‘X’ axis, and said another rack (3) and other two pinion assemblies (5 & 6) are assembled in horizontal ‘Y’ axis, in which the rack and pinion assemblies at the horizontal ‘Y’ axis are assembled in-between an inverted ‘U’ bracket (7), wherein the two twisted flat strip assemblies (8 & 9) are fixed to the two pinion assemblies (3B & 3C) in the horizontal ‘Y’ axis in which two CO2 welding torches (10 & 11) are made to hold.

8. The apparatus as claimed in claim 7, wherein the included angle of the job (1) to be welded (‘I’ beam) is 90 degrees, which is being located and welded at ‘V’ position, in which two CO2 welding torches (2 & 3) are subjected in welding process at one point which are tilted to the working angle of 25 degrees from the surface of the job (‘I’ beam) that it forms an included angle of 40 degrees to each other.

9. The apparatus as claimed in claim 7 or 8, wherein the apparatus is made to be held rigidly in a cantilever support (1).