Note: Descriptions are shown in the official language in which they were submitted.
CA 02898929 2015-07-29
METHOD FOR WELDING METAL COMPONENTS
FIELD OF THE INVENTION
The present invention relates to a method for welding metal
components and particularly to a welding method
incorporating with a paste filling process.
BACKGROUND OF THE INVENTION
Welding is a widely adopted technique that usually aims to
join at least two metal pieces intended for assembly by
welding to form a complete weld at the junction of the two
metal pieces to produce improved structural strength after the
welding is finished.
However, during the welding process of the metal pieces a
molten crater is formed on the surfaces thereof and a solder is
added to aid welding. As a result, after the welding is finished
the weld is jutting noticeably from the metal surfaces that
makes the metal surfaces no longer neat or smooth. Hence an
additional grinding process usually is needed to trim the metal
surfaces that result in higher fabrication cost. There is still
room for improvement.
SUMMARY OF THE INVENTION
The primary object of the present invention is to solve the
problems of the conventional technique of higher cost and
requiring extra grinding.
To achieve the foregoing object the present invention
provides a method for welding metal components that
CA 02898929 2015-07-29
comprises the following steps:
Material preparing step: Provide a first metal piece and a
second metal piece. The first metal piece has a first working
portion intended to join the second metal piece, and the
second metal piece has a second working portion intended to
join the first metal piece;
Welding preparing step: Position the second working
portion of the second metal piece against the first working
portion of the first metal piece to jointly define an intended
welding seam;
Local welding step: Perform local welding on the intended
welding seam to form a plurality of welding zones and a
plurality of non-welding zones thereon that are spaced from
each other; and
Local paste filling step: Fill a bonding paste to each
non-welding zone and cure the bonding paste in a curing
condition to mask the non-welding zone to finish welding of
the first metal piece and the second metal piece to form a
metal component.
In one embodiment the curing condition at the local paste
filling step is a drying time after elapse thereof the bonding
paste is cured on the welded first metal piece and the second
metal piece.
In another embodiment the curing condition at the local
paste filling step is a curing temperature to cure the bonding
2
CA 02898929 2015-07-29
,
,
,
paste on the welded first metal piece and the second metal
piece.
In yet another embodiment the bonding paste at the local
paste filling step is an ultraviolet ray curing paste and the
curing condition is providing an ultraviolet ray to project on
the bonding paste to generate curing thereof on the welded
first metal piece and the second metal piece.
In yet another embodiment the local paste filling step
further is followed by a grinding step to grind the welding
zone so that the surface of the intended welding seam is neat
and smooth to match the surface of the first metal piece or the
second metal.
In yet another embodiment the grinding step further
includes a sub-step of grinding the non-welding zones at the
same time after paste filling.
In yet another embodiment the grinding step is followed
by a trimming step to make coloration on the total surface of
the metal component to change surface characteristics of the
metal component.
In yet another embodiment the welding zones at the local
welding step has a total length greater than at least 30% of the
total length of the intended welding seam.
Through the method set forth above, compared with the
conventional technique, the invention can provide many
advantageous features, notably:
3
CA 02898929 2015-07-29
1. In a condition of producing a same structural strength
the invention provides local welding on the first metal piece
and the second welding piece intended for welding, and can
form a weld shorter than that of the conventional technique
after the welding is finished, thus can reduce grinding portion,
consequently make welding cost lower.
2. By filling the bonding paste in the non-welding zones
to mask the intended welding seam and form a smoother
surface after curing, grinding potion required at the
downstream process can be reduced.
The foregoing, as well as additional objects, features and
advantages of the invention will be more readily apparent
from the following detailed description, which proceeds with
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowchart of a first embodiment of the invention.
FIGS. 2A through 2D are implementation schematic views of
the first embodiment of the invention.
FIGS. 3A through 3D are implementation schematic views of
a second embodiment of the invention.
FIG. 4 is a flowchart of a third embodiment of the invention.
FIG. 5 is a flowchart of a fourth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED
EMBODIMENTS
The present method aims to provide a method for welding
4
CA 02898929 2015-07-29
metal components to weld a plurality of metal pieces to form a
metal component. Please referring to FIG. 1, the method
comprises the following steps: material preparing step 10,
welding preparing step 11, local welding step 12 and local
paste filling step 13. More specifically, also referring to FIGS.
2 and 3, at the material preparing step 10, provide a first metal
piece 20 and a second metal piece 21. The first metal piece 20
and the second metal piece 21 can be respectively a metal tube
or a metal plate. To facilitate discussion, metal plates are
adopted in the embodiments of the first metal piece 20 and the
second metal piece 21 herein. According to assembly
requirement the first metal piece 20 has a first working
portion 201 intended to join the second metal piece 21, and
the second metal piece 21 has a second working portion 211
intended to join the first metal piece 20, as shown in FIG. 2A.
Next, the welding preparing step 11, please referring to
FIG. 2B, prepare to make preassembly of the first metal piece
and the second metal piece 21 by positioning the second
working portion 211 of the second metal piece 21 against the
20 first working portion 201 of the first metal piece 20 to jointly
define an intended welding seam 22. Next, enter the local
welding step 12: perform local welding on the intended
welding seam 22 to form a plurality of welding zones 221 and
a plurality of non-welding zones 222 that are spaced from
each other. Furthermore, the welding technique employed in
5
CA 02898929 2015-07-29
the invention can be, but not limited to, arc welding, gas
welding, resistance welding, brazing or soldering. At the local
welding step 12, preset a welding start spot and perform
welding for a selected distance to form one welding zone 221,
then stop welding on the intended welding seam 22 for
another selected distance to form one non-welding zone 222;
next, perform another welding on the intended welding seam
22 to form another welding zone 221; such a process cycle is
repeated as shown in FIG. 2C so that a weld is formed in an
intermittent manner on the intended welding seam 22 rather
than a continuous fashion. Moreover, in one embodiment total
length of the welding zones 221 is at least 30% of the total
length of the intended welding seam 22. However, the total
length ratio of the welding zone 221 against the total length of
the intended welding seam 22 can be adjusted according to
desired structural length to be made for the metal component.
Please referring to FIG. 2D, after the local welding step 12
is finished, enter the local paste filling step 13: fill a bonding
paste 23 to each non-welding zone 222 and cure the bonding
paste 23 in a curing condition to mask the non-welding zone
222 to finish welding of the first metal piece 20 and the
second metal piece 21 to form a metal component 24 as shown
in FIG. 2D. In addition, the bonding paste 23 can be selected
according to actual requirement or work environment in the
fabrication and assembly processes. For instance, the bonding
6
CA 02898929 2015-07-29
paste 23 can be a solvent-based bonding paste, an emulsified
polymer bonding paste, a heated bonding paste or ultraviolet
ray curing paste. In one embodiment the curing condition is a
drying time. After the bonding paste is filled at the local paste
filling step 13 and the first metal piece 20 and the second
metal piece 21 are maintained for a duration of the drying
time the bonding paste 23 is cured. The drying time can vary
by selecting different types or different blending proportions
of the bonding paste. In another embodiment the curing
condition is a curing temperature. After the bonding paste is
filled at the local paste filling step 13, place the metal
component 24 in a heated baking equipment, or provide hot
air to the metal component 24 via a portable hot air equipment
to provide the curing temperature to the intended welding
seam 22 formed on the first metal piece 20 and the second
metal piece 21 to cure the bonding paste 23. In yet another
embodiment curing of the bonding paste 23 is accomplished
through an ultraviolet ray curing paste, and the curing
condition is projecting an ultraviolet ray to the bonding paste
23 on the metal component 24 to form curing thereof.
Furthermore, after the ultraviolet ray curing paste is cured it is
unlikely to be changed by other ordinary physical conditions
(such as temperature). The cured ultraviolet ray curing paste
can be changed and removed only by using a release solvent.
Thus when the ultraviolet ray curing paste is selected change
7
CA 02898929 2015-07-29
,
of the metal component 24 in the downstream fabrication
process due to work environmental factors (such as
temperature) can be prevented.
As previously discussed, the metal component 24 finished
via the welding method of the invention has only the welding
zones 221 formed by local welding while the remained
portions are the masked non-welding zones 222 formed by
filling the bonding paste 23, hence the portion of the intended
welding seam 22 that require downstream fabrication (such as
grinding) is smaller, and the solder needed during the welding
process also can be reduced. .
Please referring to FIGS. 1, and 3A through 3D, the
method of the invention, in addition to be used on welding the
metal plates, also can be used on welding metal tubes as
shown in the drawings. At the material preparing step 10 the
first metal piece 20 and the second metal piece 21 of metal
tubes are provided that have respectively the intended first
working portion 201 and the second working portion 211. At
the welding preparing step 11 the first metal piece 20 and the
second metal piece 21 are preassembled to jointly define an
intended welding seam 22 via the first working portion 201
and the second working portion 211. Then enter the local
welding step 12 to do welding as previously discussed or on at
least two opposite lateral sides of the second metal piece 21
with the finished weld fully covered one lateral side of the
8
CA 02898929 2015-07-29
second metal piece 21 to form the welding zone 221 as shown
in FIG. 3C, while the remained lateral sides formed the
non-welding zone 222; then enter the local paste filling step
13 to fill the bonding paste 23 in the non-welding zone 222 at
the lateral side of the second metal piece 21; finally perform
curing on the bonding paste 23 in the curing condition to
finish welding to form the metal component 24.
The invention also makes test comparisons of the
structural strength between the metal component 24 made via
the method of the invention and the conventional welding
technique. Test outcomes show that the structural strength of
the metal component 24 made via the method of the invention
is proximate that of the conventional metal structure without
seriously damaging the structural strength, hence prove the
method of the invention can produce same degree of structural
strength and reduce welding portion and the consumed solder
material and cost.
Please referring to FIG. 4, in another embodiment of the
invention the method further includes a grinding step 14 of
grinding the welding zones 221 after the local paste filling
step 13 to smooth the surface of the intended welding seam 22
to match the surface of the first metal piece 20 or the second
metal piece 21, thereby makes the metal component 24 more
appealing in appearance. Furthermore, also referring to FIG. 4,
at the local paste filling step 13 the bonding paste 23 could be
9
CA 02898929 2015-07-29
filled unevenly, hence in yet another embodiment the grinding
step 14 further includes a grinding sub-step 141 for the
non-welding zones 222 after filling the paste to make the
surface of the intended welding seam 22 evenly formed.
Please also referring to FIG. 5, in yet another embodiment the
grinding step 14 further is followed by a trimming step 15 by
making coloration on the entire surface of the metal
component 24 to change the surface characteristics thereof
More specifically, after the metal component 24 is finished,
according to design or appearance requirements, selected paint
can be coated on the metal component 24 by spraying or the
like to change the surface characteristics.
As a conclusion, the method for welding metal
components provided by the invention can produce a metal
component by welding a first metal piece and a second metal
piece. During implementation of the method the first metal
piece and the second metal piece are positioned with a first
working portion and a second working position jointly defined
an intended welding seam; next, perform local welding on the
intended welding seam to form a plurality of welding zones
and a plurality of non-welding zones that are spaced from
each other; next, provide a bonding paste to fill the
non-welding zones and provide a curing condition to cure the
bonding paste to mask the non-welding zones to finish
welding of the first metal piece and the second metal piece to
CA 02898929 2015-07-29
form the metal component. As a result, in a given condition of
the same structural strength the invention can resolve the
problems of higher cost and extra grinding that occur to the
conventional technique.
11
