International Journal of Engineering Trends and Technology (IJETT) - Volume4 Issue7- July 2013
Automation in Sheet Metal Tig Welding Process: A Case Study
Author: Roshan W.Ttulankar
Author: Suraj S. Dehankar
Student
Student
Department Of Mechanical Engg.
Department Of Mechanical Engg.
J.D.I.E.T. Yavatmal, India
J.D.I.E.T. Yavatmal, India
Abstract- The paper deals with the designing of mechanism, which
machines for TIG welding. But in the long run it would again
can weld the silencer shells of sheet metal in a linear motion with an
turnout to be an expensive affair as regards maintenance, repair
improved degree of fineness and are relatively less cumbersome than
or replacement of any of the machine parts.
traditional welding process. The technical constraint that has to be
considered while designing and developing the mechanism was to
This creates the need for an indigenously made
achieve the stability, linear and uniform speed of welding torch and
automatic TIG welding mechanism which would minimize direct
uniform weld thickness for quality product. The details of testing on
exposure of welder to hazardous fumes and bright light of arc.
various silencer shells are given in paper. In near future variable
frequency drive (VFD) can be installed for its full atomization.
overcoming the drawbacks in the present manual welding
process.
Keyword: TIG Welding, VFD.
I.
Also minimize the time consumption for TIG welding, thus
INTRODUCTION
In manual TIG welding process the production rate is
Unlike other developed countries, we are still lagging
less & due to the non-uniformity in the linear motion, the
behind in advancement of machineries. Instead of utilizing
accuracy and quality of welding gets adversely affected. But in
automated machines, we are quite habitual of the traditional
case of this mechanism, the motion is uniform while welding & it
methods of production. On the other hand, developed countries
helps to avoid the pits and bulges forming due to an-uniformity in
are more focused to bring automation in every sector of
the movement of welders hand.
production. This has immensely helped them in reducing
production time, wastage of material, etc. Automation provides
accuracy, quality as well as requires less time and man power.
II.
TIG WELDING
Despite of losses in old methods of manufacturing and hazards
TIG welding (Tungsten inert gas welding) is also called
associated with them, small scale industries do not prefer
as gas Tungsten Arc Welding (GTAW) uses a non consumable
automated machines or special purpose machines for specific
electrode and a separate filler metal with an inert shielding
work. Most of the work in production is done manually.
gas.[5] This is the term used by welding engineers on blueprints,
Manpower is involved in the process instead of the machine as it
and in welding procedures. When TIG was introduced around the
is unaffordable for small scale industries. It is needed to enhance
1940’s it used to be referred to as “HeliArc” because the
the old machineries by automating them in order to get more
shielding gas used was helium.[6] It is no longer called HeliArc
benefits.
because in most cases the shielding gas used is Argon.
Whereas the arena is somewhat different in large scale
It is an arc welding process that uses a non-consumable
industries, they generally buy too costly special purpose
tungsten electrode to produce the weld.[4] Some welds, which
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International Journal of Engineering Trends and Technology (IJETT) - Volume4 Issue7- July 2013
join thin materials, (known as autogenous or fusion welds) can be
GTAW is comparatively more complex and difficult to master as
accomplished without filler metal; most notably edge, corner, and
it requires greater welder dexterity than MIG or stick welding and
butt joints. The weld area is protected from atmospheric
furthermore, it is significantly slower than most other welding
contamination by an inert shielding gas (argon or helium). A
techniques. A related process, plasma arc welding, uses a slightly
constant-current welding power supply produces energy which is
different welding torch to create a more focused welding arc and
conducted across the arc through a column of highly ionized gas
as a result is often automated.[3]
and metal vapour known as plasma.[1,2&3]
Weld Discontinuities: Undercutting, Tungsten inclusions,
Porosity, Weld metal cracks, Heat affected zone cracks.
TIG
Welding Problems: Erratic
arc,
Excessive
electrode
consumption, Oxidized weld deposit, Arc wandering, Porosity,
Difficult arc starting.[1]
TIG Welding Benefits :i. Superior quality welds. ii. Welds can be
made with or without filler metal. iii. Precise control of welding
variables (heat). iv. Free of spatter. v. Low distortion.[2]
III.
THE NECESSITY OF AUTOMATION
The TIG welding process is carried out for welding the
shells of cylindrical and conical shape which are made by metal
sheet of 1.2 & 1.5 mm thickness. previously this work was done
Fig.1 Setup of TIG Welding.
manually.
Manual GTAW is often considered the most difficult of
The reasons which were discussed are as follows,
all the welding processes commonly used in industry. Because
the welder must maintain a short arc length, great care and skill
•
amount of Tungsten fumes produced in welding process;
are required to prevent contact between the electrode and the
work piece. TIG welding is most commonly used to weld thin
Adverse effect on Health of welding gun operator due to
•
sections of stainless steel and non-ferrous metals such as
Non -Uniformity of the weld due to shaking of hand
while moving of torch.
aluminium, magnesium, and copper alloys. The process grants
the operator greater control over the weld than competing
processes such as shielded metal arc welding and gas metal arc
welding, allowing for stronger, higher quality welds. However,
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•
safety of the operator;.
•
The available SPM in the market is very costly, small
scale industries doesn’t afford this SPM.
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International Journal of Engineering Trends and Technology (IJETT) - Volume4 Issue7- July 2013
Fig.2 Fumes produced during welding
IV.
DESIGN OF COMPONENT
Design of belt:
Fig. 3 Irregularities in weld
Design of lead screw
Overall Length : 35inches
Centre distance=3.5×diameter of larger pulley [12]
Length of threaded portion : 25 inches
=3.5×10
Calculation of lead screw
=35 inch
P= 180 watt
Length of belt=L= 2C+
π(
) (
+
)
L=89inch
T= =
Design of pulley:
=
×
π
×
π×
Size of larger pulley 10inch
= 4.47 N-m
Size of smaller pulley 2.5inch
T= ×τ×d3
∴τ=42
Mpa (Given) [12]
Calculation for pulley
d =8.7 mm
=
[10]
By considering Bending Moment
=
When torch is at center position then,
D2=10 inch
M=
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=
× .
×
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International Journal of Engineering Trends and Technology (IJETT) - Volume4 Issue7- July 2013
=3237.3 N-mm.
rotating and torch starts welding automatically as soon as
electrode come in front of metal sheet cylinder surface and
Twisting Moment
Te =√
electrode. The welding was held continuously till the shell ends.
After completion of welding in this forward stroke motor was
+
stopped and shell was replaced by new un-weld shell and motor
Te =5519.14 N-mm.
Te =
allowed to start rotating in reverse direction. In the same way that
shell also welded and same procedure is repeated for other shells
×τ×d3
for welding. In this the reverse-forward motion and stopping of
the torch is controlled by the R/F switch.
d= 8.74mm.
V.
WORKING
The TIG welding machine should be in off condition
before starting an operation. Torch should be kept on either side
of the mechanism. Silencer shell which is to be weld is then kept
on the magnetic fixture. The distance is adjusted between sheet
shell surface and tip of tungsten electrode by slight adjustment of
nuts provided on the bolt attached to the fixtures. Also edge line
is matched by moving the pointers over it. This given
arrangement provides the scope to fixture to move in both X & Y
direction. Current, voltage and Argon gas flow is checked and
adjusted them all to the required value. TIG welding machine is
switched ON. Then the supply is given to the motor, motor starts
Fig.4 Mechanism
I.
PERFORMANCE ANALYSIS
The percentage of quality achieved is considered on the basis of
proportion of fine welded length as to total length welded
Table 1 For sheet thickness =1.2mm (Conical Shell)
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No
Length(mm)
By Manual
of
Time
Quality
trials
(sec)
%
By Mechanism
Time(sec)
Quality
%
1
610
35
76 %
33
92 %
2
610
36
75 %
34
94 %
3
610
34
80 %
33
92 %
4
610
37
73 %
33
95 %
5
610
36
75 %
33
94 %
6
610
35
77 %
33
93 %
7
610
36
74 %
34
93 %
8
610
34
80 %
33
92 %
9
610
37
76 %
33
95 %
10
610
36
79 %
33
94 %
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International Journal of Engineering Trends and Technology (IJETT) - Volume4 Issue7- July 2013
No
Length(mm)
By Manual
of
Time
Quality
trials
(sec)
%
By Mechanism
Time(sec)
Quality
%
1
610
33
75 %
31
90 %
2
610
32
80 %
31
97 %
3
610
34
73 %
31
92 %
4
610
31
70 %
30
95 %
5
610
32
74 %
30
95 %
6
610
34
70 %
30
96 %
7
610
33
72 %
31
95 %
8
610
35
75%
31
95 %
9
610
34
72 %
31
96 %
No
10
610
32
78 %
30
98 %
of
Time
Quality
trials
(sec)
%
Table 3 For sheet thickness =1.5mm (Cylindrical Shell)
No
Length(mm)
By Manual
of
Time
Quality
trials
(sec)
%
By Mechanism
Time(sec)
Quality
%
1
520
27
76 %
27
96 %
2
520
28
75 %
27
93 %
3
520
26
55 %
27
90 %
4
520
29
72 %
26
92 %
5
520
29
81 %
27
97 %
6
520
27
76 %
27
94 %
7
520
28
75 %
27
94 %
8
520
26
73 %
27
96 %
9
520
29
66 %
26
96 %
10
520
29
81 %
27
98 %
Table 2 For sheet thickness =1.2mm (Cylindrical Shell)
Table 4 For sheet thickness =1.5mm (Conical Shell)
Length(mm)
By Manual
By Mechanism
Time(sec)
Quality
%
1
520
25
71 %
24
92 %
2
520
27
73 %
25
95 %
3
520
26
74 %
24
93 %
4
520
28
72 %
25
94 %
5
520
26
75 %
25
94 %
6
520
25
56 %
25
92 %
7
520
26
60 %
25
95 %
8
520
26
74 %
25
93 %
9
520
28
74 %
25
94 %
10
520
27
72 %
25
94 %
performance analysis, It observed that the silencer shell welded
using this mechanism discussed in this study are better in quality
II.
CONCLUSION
The mechanism reported in this study can weld silencer
shells for variety of popular bikes like Splendor, CT-100, CDDawn, Passion, Pulsar, Discover, etc. A lead screw is used to
and required less time than manual welding. Thus the mechanism
offers an efficient and less expensive alternative for the TIG
welding process and also reduces the human involvement thereby
reducing the health hazard and safety hazard.
convert rotational motion into uniform linear motion. TIG
welding torch is mounted on the lead screw nut. The lead screw
is coupled to an induction motor with V-belt. R/F switch helps in
reversal of the direction of movement. From the table of
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International Journal of Engineering Trends and Technology (IJETT) - Volume4 Issue7- July 2013
REFERANCES
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