U.S. patent application number 14/470009 was filed with the patent office on 2014-12-11 for laser welding device for roll forming system and control method thereof.
The applicant listed for this patent is SUNGWOO HITECH CO., LTD.. Invention is credited to Mun-Yong LEE, Hyun-Uk SEOL.
Application Number | 20140360990 14/470009 |
Document ID | / |
Family ID | 46021352 |
Filed Date | 2014-12-11 |
United States Patent
Application |
20140360990 |
Kind Code |
A1 |
LEE; Mun-Yong ; et
al. |
December 11, 2014 |
LASER WELDING DEVICE FOR ROLL FORMING SYSTEM AND CONTROL METHOD
THEREOF
Abstract
A roll forming system which roll-forms a shaped beam by a roll
forming unit including a plurality of roll formers is disclosed. A
laser welding device for the roll forming system may include: front
and rear guide means disposed apart from each other at the rear of
the roll forming unit, and guiding movement of the shaped beam;
laser welding means mounted above and between the front and rear
guide means, reciprocatedly rotating a mirror by controlling a
mirror motor so as to irradiate a laser beam to a welding position
of the shaped beam, and thereby forming a welding bead having a
predetermined welding pattern; forming speed detecting means
detecting a forming speed of the shaped beam and transmitting a
signal corresponding thereto to a controller; a camera disposed at
the rear of the laser welding means, photographing a welding
portion of the shaped beam, and transmitting an image signal
corresponding thereto to the controller.
Inventors: |
LEE; Mun-Yong; (Pusan-city,
KR) ; SEOL; Hyun-Uk; (Pusan-city, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SUNGWOO HITECH CO., LTD. |
Pusan-city |
|
KR |
|
|
Family ID: |
46021352 |
Appl. No.: |
14/470009 |
Filed: |
August 27, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12969665 |
Dec 16, 2010 |
8847107 |
|
|
14470009 |
|
|
|
|
Current U.S.
Class: |
219/121.62 |
Current CPC
Class: |
B23K 26/24 20130101;
B23K 26/262 20151001; B23K 26/0846 20130101; Y10T 29/49888
20150115; B23K 26/032 20130101 |
Class at
Publication: |
219/121.62 |
International
Class: |
B23K 26/03 20060101
B23K026/03; B23K 26/24 20060101 B23K026/24; B23K 26/08 20060101
B23K026/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2010 |
KR |
10-2010-0117722 |
Claims
1. A control method of a laser welding device for a roll forming
system, comprising: (a) detecting a forming speed of a shaped beam;
(b) laser welding each welding position of the shaped beam by
controlling an output and a moving speed of a focus of a laser beam
to be reference values; (c) determining whether the forming speed
is within a predetermined error range; (d) receiving and analyzing
image information of the welding position of the shaped beam in a
case that the forming speed is within the predetermined error
range; (e) determining whether an analyzed welding pattern analyzed
from the image information maintains a predetermined welding
pattern; and (f) maintaining the output and the moving speed of the
focus of the laser beam in a case that the analyzed welding pattern
maintains the predetermined welding pattern.
2. The control method of claim 1, wherein the output and the moving
speed of the focus of the laser beam are controlled according to
the forming speed detected in real time before performing the step
(d) in a case that the forming speed is out of the predetermined
error range at the step (c).
3. The control method of claim 1, wherein a malfunction signal is
output and the control method of the laser welding device is
finished in a case that the analyzed welding pattern does not
maintain the predetermined welding pattern at the step (e).
4. The control method of claim 1, wherein the predetermined welding
pattern is set as a contour of a welding bead formed along a
predetermined zigzag line.
5. The control method of claim 4, wherein information about the
contour of the welding bead is stored as the predetermined welding
pattern.
6. The control method of claim 1, wherein the analyzed welding
pattern is a contour of the welding bead recognized from shading
difference between a basic material and the welding bead at each
welding position of the shaped beam.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional Application of U.S. patent
application Ser. No. 12/969,665 Filed Dec. 16, 2010, which claims
priority to and the benefit of Korean Patent Application No.
10-2010-0117722 filed in the Korean Intellectual Property Office on
Nov. 24, 2010, the entire contents of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] (a) Field of the Invention
[0003] The present invention relates to a laser welding device for
a roll forming system and a control method thereof. More
particularly, the present invention relates to a laser welding
device for a roll forming system and a control method thereof which
is disposed at the rear of a roll forming unit and laser welds each
welding position of a shaped beam in real time by controlling an
output and a moving speed of a focus of a laser beam according to a
forming speed.
[0004] (b) Description of the Related Art
[0005] Generally, a roll forming method is a method in which a coil
is uncoiled and the coil is bent to various shapes by passing
through a roll forming unit including a plurality of roll formers
respectively provided with an upper forming roll and a lower
forming roll. The roll forming method is used for manufacturing
beams of linear type (particularly, a bumper beam for a vehicle)
which is bent to the various shapes.
[0006] FIG. 1 is a schematic diagram of a roll forming system
according to a conventional art which performs a roll forming
method.
[0007] As shown in FIG. 1, the roll forming system according to the
conventional art includes an uncoiler 201 at a front portion of a
process line, and the uncoiler 201 performs an uncoil step S110 at
which a coil 200 is uncoiled. A straightener 203 is provided at the
rear of the uncoiler 201 and performs a straightening step S120 at
which the coil uncoiled from the uncoiler 201 is straightened to a
panel 250 of plate shape.
[0008] In addition, a brake press 205 is disposed at the rear of
the straightener 203 and performs a piercing step S130 at which a
plurality of holes for assembling is formed at the panel 250
supplied from the straightener 203.
[0009] In addition, a roll forming unit 207 including at least
seven roll formers R1-R7 is disposed at the rear of the brake press
205 and performs a roll forming step S140 at which the panel 250
passing through the uncoiler 201, the straightener 203, and the
brake press 205 is sequentially bent such that a shaped beam 260 is
formed.
[0010] In addition, a round bender 209 for forming the shaped beam
260 to have a predetermined curvature is disposed at the rear of
the roll forming unit 207. The round bender 209 is provided with a
shaped surface having the predetermined curvature and performs a
bending step S150 at which the shaped beam 260 passes through the
shaped surface so as to be manufactured as the shaped beam 260
having the predetermined curvature.
[0011] In addition, a cutting press 211 for cutting the shaped beam
260 in a predetermined size is disposed at the rear of the round
bender 209 and performs a cutting step S160 at which the shaped
beam 260 is cut in a size of the finished product.
[0012] A bumper beam 300 for a vehicle bent to have a closed
section, as shown in FIG. 2, is manufactured through the roll
forming system.
[0013] However, in a case of the bumper beam 300, both ends of the
closed section should be welded through a spot welding (SW) or a
cold metal transfer (CMT) welding at an additional welding
process.
[0014] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
invention and therefore it may contain information that does not
form the prior art that is already known in this country to a
person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0015] The present invention has been made in an effort to provide
a laser welding device for a roll forming system and a control
method thereof having advantages that additional welding processes
are not required by laser welding a shaped beam which is
roll-formed at the rear of a roll forming unit in real time.
[0016] In addition, an another objective of the present invention
is that an output and a moving speed of a focus of a laser beam are
controlled in real time according to a forming speed of a shaped
beam such that a welding bead along a predetermined zigzag line is
formed at a welding position of the shaped beam. Accordingly,
quality of laser welding may be improved.
[0017] A laser welding device for a roll forming system which
roll-forms a shaped beam through a roll forming unit provided with
a plurality of roll formers, may include: front and rear guide
means disposed apart from each other at the rear of the roll
forming unit, and guiding movement of the shaped beam; laser
welding means mounted above and between the front and rear guide
means, reciprocatedly rotating a mirror by controlling a mirror
motor so as to irradiate a laser beam to a welding position of the
shaped beam, and thereby forming a welding bead having a
predetermined welding pattern; forming speed detecting means
detecting a forming speed of the shaped beam and transmitting a
signal corresponding thereto to a controller; and a camera disposed
at the rear of the laser welding means, photographing a welding
portion of the shaped beam, and transmitting an image signal
corresponding thereto to the controller.
[0018] The front and rear guide means may respectively include: a
guide frame; a lower guide roller mounted at a lower portion of the
guide frame through a slider, and rolling guiding a lower surface
of the shaped beam; and an upper guide roller mounted at an upper
portion of the guide frame through a slider, and rolling guiding an
upper surface of the shaped beam.
[0019] The laser welding means may include: a laser oscillator
oscillating the laser beam according to a control of the
controller; a housing mounted at an upper portion of the rear guide
means through a bracket; a optic head mounted at a side of the
housing, and provided therein with an optical system controlling a
focus of the laser beam oscillated by the laser oscillator; the
mirror provided in the housing, and reflecting the laser beam
outputting from the optic head to the welding position of the
shaped beam; and the mirror motor provided in the housing, and
controlling a reflecting angle of the mirror by the controller so
as to move the focus of the laser beam irradiated to the welding
position of the shaped beam reciprocatedly within a predetermined
width.
[0020] The mirror motor may be a step motor which can rotate
clockwise or counterclockwise.
[0021] The forming speed detecting means may include: a rotating
roller rolling contacted with the lower surface of the shaped beam
and rotating proportional to the forming speed of the shaped beam;
and an encoder motor connected to the rotating roller so as to
rotate with the rotating roller, and transmitting a signal
corresponding to a rotation speed of the rotating roller to the
controller.
[0022] The rotating roller may be made of urethane or rubber being
elastic.
[0023] A control method of a laser welding device for a roll
forming system, may include: (a) detecting a forming speed of a
shaped beam; (b) laser welding each welding position of the shaped
beam by controlling an output and a moving speed of a focus of a
laser beam to be reference values; (c) determining whether the
forming speed is within a predetermined error range; (d) receiving
and analyzing image information of the welding position of the
shaped beam in a case that the forming speed is within the
predetermined error range; (e) determining whether an analyzed
welding pattern analyzed from the image information maintains a
predetermined welding pattern; and (f) maintaining the output and
the moving speed of the focus of the laser beam in a case that the
analyzed welding pattern maintains the predetermined welding
pattern.
[0024] The output and the moving speed of the focus of the laser
beam may be controlled according to the forming speed detected in
real time before performing the step (d) in a case that the forming
speed is out of the predetermined error range at the step (c).
[0025] A malfunction signal may be output and the control method of
the laser welding device may be finished in a case that the
analyzed welding pattern does not maintain the predetermined
welding pattern at the step (e).
[0026] The predetermined welding pattern may be set as a contour of
a welding bead formed along a predetermined zigzag line.
[0027] Information about the contour of the welding bead may be
stored as the predetermined welding pattern.
[0028] The analyzed welding pattern may be a contour of the welding
bead recognized from shading difference between a basic material
and the welding bead at each welding position of the shaped
beam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a schematic diagram of a conventional roll forming
system.
[0030] FIG. 2 is a perspective view of a bumper beam for a vehicle
manufactured by a conventional roll forming system.
[0031] FIG. 3 is a schematic diagram of a roll forming system to
which a laser welding device according to an exemplary embodiment
of the present invention is applied.
[0032] FIG. 4 is a side view of a laser welding device according to
an exemplary embodiment of the present invention.
[0033] FIG. 5 is a schematic diagram showing an operation of a
laser welding device according to an exemplary embodiment of the
present invention.
[0034] FIG. 6 is a block diagram showing constituent elements for
controlling a laser welding device according to an exemplary
embodiment of the present invention.
[0035] FIG. 7 is a top plan view of a shaped beam illustrating a
predetermined welding pattern of a welding portion by a laser
welding device according to an exemplary embodiment of the present
invention.
[0036] FIG. 8 is a flowchart showing a control method of a laser
welding device according to an exemplary embodiment of the present
invention.
[0037] FIG. 9 is a perspective view of a shaped beam manufactured
by a roll forming system to which a laser welding device according
to an exemplary embodiment of the present invention is applied.
TABLE-US-00001 <Description of symbols> 1: uncoiler 2:
straightener 3: brake press 4: roll forming unit 5: laser welding
device 6: round bender 7: cutting press 10: coil 9: base 20: panel
30, 40, 50, 60: shaped beam 110, 120: front and rear guide means
130: laser welding means 140: forming speed detecting means 150:
camera 111, 121: guide frame 113, 123, 117, 127: slider 115, 125,
119, 129: guide roller 131: laser oscillator 132: housing 133:
bracket 134: optic head 135: optical fiber cable 136: mirror 137:
mirror motor 141: rotating roller 143: encoder motor WL: zigzag
line V: forming speed LB: laser beam WP: welding position B:
welding bead W: welding portion C: controller SP: predetermined
welding pattern Wd: width P: pitch L: length
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] Hereinafter, an exemplary embodiment of the present
invention will be described in detail with reference to the
accompanying drawings.
[0039] FIG. 3 is a schematic diagram of a roll forming system to
which a laser welding device according to an exemplary embodiment
of the present invention is applied, and FIG. 4 is a side view of a
laser welding device according to an exemplary embodiment of the
present invention.
[0040] A roll forming system to which a laser welding device
according to an exemplary embodiment of the present invention is
applied, as shown in FIG. 3, includes an uncoiler 1 disposed at the
front of a process line and uncoiling a coil 10.
[0041] A straightener 2 is disposed at the rear of the uncoiler 1
and straightens the coil 10 uncoiled from the uncoiler 1 to a panel
20 of plate shape.
[0042] In addition, a brake press 3 is disposed at the rear of the
straightener 2 and forms a plurality of holes for assembling a
shaped beam at a panel 20 delivered from the straightener 2.
[0043] A roll forming unit 4 is disposed at the rear of the brake
press 3. The roll forming unit 4 sequentially bends the panel 20
passing through the straightener 2 and the brake press 3 so as to
roll-form the shaped beam 30 having a closed section.
[0044] The roll forming unit 4 includes at least seven roll formers
R1-R7 disposed in series.
[0045] In addition, a laser welding device 5, as shown in FIG. 4,
is disposed at the rear of the roll forming unit 4. The laser
welding device 5 performs laser welding at a welding position of
the shaped beam 30.
[0046] A round bender 6 including a plurality of curvature forming
rolls is disposed at the rear of the laser welding device 5. The
rounder bender 6 forms the shaped beam 40 passing through welding
process to have a predetermined curvature.
[0047] In addition, a cutting press 7 for cutting the shaped beam
50 having the predetermined curvature in a predetermined size is
disposed at the rear of the round bender 6.
[0048] The laser welding device 5, as shown in FIG. 4, includes
front and rear guide means 110 and 120, laser welding means 130,
forming speed detecting means 140, and a camera 150.
[0049] The front guide means 110 and the rear guide means 120 are
disposed on a base 9 between a rearmost roll former R7 of the roll
forming unit 4 and the round bender 6. The front guide means 110
and the rear guide means 120 are disposed apart from each other by
a predetermined distance and guide a movement of the shaped beam
30.
[0050] Herein, the front and rear guide means 110 and 120 have the
same constitution, function, and shape.
[0051] That is, the front and rear guide means 110 and 120
respectively includes guide frames 111 and 121 mounted on the base
9.
[0052] Lower guide rollers 115 and 125 for rolling guiding a lower
surface of the shaped beam 30 are rotatably mounted at lower
portions of the guide frames 111 and 121 through sliders 113 and
123.
[0053] In addition, upper guide rollers 119 and 129 for rolling
guiding an upper surface of the shaped beam 30 are rotatably
mounted at upper portions of the guide frames 111 and 121 through
sliders 117 and 127.
[0054] The front and rear guide means 110 and 120 rolling contacts
with the shaped beam 30 which is roll-formed by the roll forming
unit 4 with a constant speed and guides it through the upper guide
rollers 119 and 129 and the lower guide rollers 115 and 125.
[0055] That is, the upper guide rollers 119 and 129 and the lower
guide rollers 115 and 125 correct spring back of the shaped beam 30
caused by residual stress and prevent both ends of the shaped beam
30 which is a welding position WP when laser welding by the laser
welding device 5 from being spread.
[0056] In addition, the laser welding means 130 are disposed
between and above the front and rear guide means 110 and 120 and
laser weld the welding position WP of the shaped beam 30 delivered
from the roll forming unit 4.
[0057] That is, a focus of a laser beam LB oscillated from a laser
oscillator 131 is reciprocatedly moved within a predetermined width
and the laser beam LB is irradiated to the welding position WP of
the shaped beam 30. Therefore, a welding portion W having a welding
bead B of a predetermined shape is formed at the shaped beam
30.
[0058] The laser welding means 130 includes the laser oscillator
131 oscillating the laser beam LB by a control signal of a
controller C.
[0059] In addition, a housing 132 is disposed between and above the
guide frames 111 and 121 of the front and rear guide means 110 and
120. The housing 132 is mounted through a bracket 133 at an upper
end of the guide frame 121 of the rear guide means 120.
[0060] An optic head 134 is provided at one side of the housing
132. The optic head 134 is connected to the laser oscillator 131
through an optical fiber cable 135, and is provided with an optical
system (not shown) therein. The optical system controls the focus
of the laser beam LB oscillated by the laser oscillator 131.
[0061] In addition, a mirror 136 is disposed in the housing 132.
The mirror 136 reflects the laser beam LB output from the optic
head 134 to the welding position WP of the shaped beam 30.
[0062] In addition, a mirror motor 137 is disposed in the housing
132 and is connected to the mirror 136 through a rotating shaft
138.
[0063] As shown in FIG. 5, the mirror motor 137 controls a
reflecting angle of the mirror 136 by the control signal of the
controller C. Accordingly, the focus of the laser beam LB is
reciprocatedly moved at the welding position WP of the shaped beam
30 within a predetermined width Wd.
[0064] The mirror motor 137 may be a step motor which can rotate
clockwise or counterclockwise, but is not limited thereto.
[0065] In addition, the forming speed detecting means 140 is
provided at one side portion of the guide frame 111 of the front
guide means 110, detects a forming speed V of the shaped beam 30,
and transmits a signal corresponding thereto to the controller
C.
[0066] The forming speed detecting means 140 includes a rotating
roller 141 rolling contacted with the lower surface of the shaped
beam 30, and the rotating roller 141 rotates with a speed
proportional to the forming speed V of the shaped beam 30.
[0067] Herein, the rotating roller 141 is made of urethane material
such that no scratch is formed at the lower surface of the shaped
beam 30 when rolling contacted with it. The rotating roller 141 may
be made of rubber material which is elastic as well as urethane
material.
[0068] In addition, an encoder motor 143 is mounted at one side
portion of the guide frame 111 of the front guide means 110. A
rotating shaft 145 of the encoder motor 143 is connected to the
rotating roller 141.
[0069] That is, the encoder motor 143 generates electric signal
according to a rotation speed of the rotating roller 141 and
transmits the signal to the controller C. The controller C
calculates the forming speed V of the shaped beam 30 based on the
signal.
[0070] The camera 150 is disposed at the rear of the guide frame
121 of the rear guide means 120, photographs the welding portion W
of shaped beam 40, and transmits image information corresponding
thereto to the controller C. A conventional CCD camera may be used
as the camera 150,
[0071] Constituent elements for controlling the laser welding
device 5 are shown in FIG. 6. That is, the controller C receives
the forming speed V of the shaped beam 30 from the encoder motor
143 and controls the output of the laser beam LB oscillated from
the laser oscillator 131 according to a predetermined value in a
predetermined map table of each forming speed.
[0072] The controller C, as shown in FIG. 5, controls the mirror
motor 137 according to the predetermined value in the predetermined
map table of each forming speed of the shaped beam 30 such that the
mirror 136 is reciprocated. At this time, the rotation speed of the
mirror 136, that is the moving speed of the focus of the laser beam
LB irradiated to the welding position WP of the shaped beam 30 is
controlled according to the forming speed V.
[0073] In addition, the controller C receives from the camera 150
the image information of the welding portion W of the shaped beam
40 which is laser welded and determines welding quality. Based on
the determination, the controller C maintains or stops operations
of the laser oscillator 131 and the mirror motor 137.
[0074] Herein, the controller C is provided with a map in which a
predetermined welding pattern SP is stored so as to determine the
welding quality of the welding portion W.
[0075] The predetermined welding pattern SP, as shown in FIG. 7, is
set as a contour of the welding bead B which is formed along a
predetermined zigzag line WL.
[0076] The predetermined welding pattern SP can be attained when
the moving speed of the focus of the laser beam LB is controlled
according to the forming speed V of the shaped beam 30.
[0077] If the output of the laser beam LB is 5.8 kW, the
predetermined welding pattern SP can be attained when the forming
speed V is 5 m/min and the moving speed of the focus of the laser
beam LB is 32 m/min. At this time, width Wd and pitch P of the
welding bead B may be 1.6 mm and 0.5 mm, respectively.
[0078] The contour of the welding bead B is converted to data
through signal processing and is stored in the predetermined
welding pattern SP of the controller C.
[0079] Meanwhile, the controller C controls the laser oscillator
131 so as to control oscillating timing of the laser beam LB.
[0080] Hereinafter, a control method of the laser welding device 5
according to an exemplary embodiment of the present invention will
be described in detail in relation to the roll forming system.
[0081] As shown in FIG. 3, an uncoil step S1 at which the coil 10
is uncoiled by using the uncoiler 1 disposed at the front of the
process line is performed.
[0082] After performing the uncoil step S1, a straightening step S2
at which the coil 10 uncoiled from the uncoiler 1 is straightened
to the panel 20 by using the straightener 2 disposed at the rear of
the uncoiler 1 is performed.
[0083] By using the brake press 3 disposed at the rear of the
straightener 2, a piercing step S3 at which a plurality of holes
for assembling is formed at the panel 20 delivered from the
straightener 2 is performed.
[0084] After that, a roll forming step S4 at which the panel 20
delivered from the brake press 3 is sequentially bent and the
shaped beam 30 having the closed section is formed by using the
roll forming unit 4 disposed at the rear of the brake press 3 is
performed.
[0085] The laser welding device 5 according to an exemplary
embodiment of the present invention, as shown in FIG. 4, is
disposed at the rear of the roll forming unit 4. A welding step S5
at which the laser beam LB is irradiated to each welding position
WP of the shaped beam 30 according to the control method of the
laser welding device shown in FIG. 8 is performed.
[0086] In addition, by using the round bender 6 disposed at the
rear of the laser welding device 5, a bending step S6 at which the
shaped beam 40 delivered from the laser welding device 5 is formed
to have a predetermined curvature is performed. A cutting step S7
at which the shaped beam 50 delivered from the round bender 6 is
cut in the predetermined size by using the cutting press 7 disposed
at the rear of the round bender 6 is performed. Accordingly, the
shaped beam 60 shown in FIG. 9 is manufactured.
[0087] Hereinafter, the control method of the laser welding device
according to an exemplary embodiment of the present invention will
be described in detail with reference to FIG. 8.
[0088] The controller C detects the forming speed V of the shaped
beam 30 through the encoder motor 143 at a step S300.
[0089] In addition, the controller C controls the output of the
laser beam LB oscillated from the laser oscillator 131 and the
moving speed of the focus of the laser beam LB according to the
rotation of the mirror motor 137 to be reference values.
Accordingly, the laser welding proceeds at a step S310.
[0090] At this time, each welding position WP of the shaped beam 30
is laser welded according to the predetermined welding pattern SP
and the welding portion W is formed.
[0091] The predetermined welding pattern SP, as shown in FIG. 7, is
set as the contour of the welding bead B formed along the
predetermined zigzag line WL at each welding position WP of the
shaped beam 30.
[0092] In addition, the controller C determines whether the forming
speed V detected by the encoder motor 143 is within a predetermined
error range at a step S320.
[0093] If the forming speed V detected in real time is within the
predetermined error range, the controller C receives and analyzes
the image information of the welding portion W on the shaped beam
30 through the camera 150 at a step S330.
[0094] On the contrary, if the forming speed V detected in real
time is out of the predetermined error range, the controller C
controls the output and the moving speed of the focus of the laser
beam LB according to the forming speed V at a step S340, and
proceeds to the step S330. The output and the moving speed of the
focus of the laser beam LB according to the forming speed V may be
set through various experiments, and may be stored in the map
table.
[0095] After performing the step S330, the controller C determines
whether an analyzed welding pattern recognized from the image
information of the welding portion W maintains the predetermined
welding pattern SP at a step S350.
[0096] If the analyzed welding pattern maintains the predetermined
welding pattern SP, the controller C controls the laser oscillator
131 and the mirror motor 137 to maintain the output and the moving
speed of the focus of the laser beam LB at a step S360.
[0097] On the contrary, if the analyzed welding pattern does not
maintain the predetermined welding pattern SP, the controller C
controls the laser oscillator 131 and the mirror motor 137 to be
stopped and outputs a malfunction signal at a step S370.
[0098] The analyzed welding pattern is a contour of the welding
bead B recognized from shading difference between a basic material
and the welding bead B at the welding portion W of the shaped beam
30 which is laser welded in real time.
[0099] That is, the analyzed welding pattern is attained by
converting the contour of the welding bead B detected by the camera
150 to data through signal processing. The controller C compares
the analyzed welding pattern with the predetermined welding pattern
SP and determines the welding quality.
[0100] The shaped beam 60 manufactured by the laser welding device
and the control method according to an exemplary embodiment of the
present invention is shown in FIG. 9. The shaped beam 60 may be
used as a bumper beam for a vehicle. At this time, the welding
beads B having a predetermined length L are formed alternately
along a length direction thereof at the back surface of the bumper
beam.
[0101] As described above, the laser welding device for roll
forming system according to the present exemplary embodiment is
applied in the roll forming system. Accordingly, after the shaped
beam 30 having the closed section is roll-formed, each welding
position WP of the shaped beam 30 may be laser welded at once. So,
additional welding processes may be removed.
[0102] In addition, the output and the moving speed of the focus of
the laser beam LB is controlled according to the forming speed V of
the shaped beam 30 in real time in the control method of the laser
welding device for the roll forming system according to an
exemplary embodiment of the present invention. Therefore, the
welding bead B having the predetermined welding pattern SP is
formed at each welding position WP of the shaped beam 30.
Accordingly, quality of the laser welding may be improved.
[0103] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *